阅读说明：本技术 用于制备嘧啶基环戊烷化合物的方法 (Process for preparing pyrimidylcyclopentane compounds ) 是由 H·伊丁 R·伦茨 M·斯卡洛内 F·戈瑟兰 于 2014-11-13 设计创作，主要内容包括：本发明涉及一种用于制备式(I)化合物的方法,其中R～1如本文所定义,所述化合物用作制备活性药物化合物的中间体。(The invention relates to a method for producing compounds of formula (I), wherein R is 1 As defined herein, the compounds are useful as intermediates in the preparation of active pharmaceutical compounds.)

1. A process for the preparation of a compound of formula (I)

Or a salt thereof, comprising a compound of formula (II)

With compounds of the formula (III)

In a coupling reaction of (b), wherein

R¹Is an amino protecting group selected from the list of benzyl, benzyloxycarbonyl (benzyloxycarbonyl, CBZ), 9-fluorenylmethyloxycarbonyl (Fmoc), p-methoxybenzyloxycarbonyl, p-nitrobenzyloxycarbonyl, tert-Butoxycarbonyl (BOC) and trifluoroacetyl;

R²is an amino protecting group selected from the list of benzyl, benzyloxycarbonyl (benzyloxycarbonyl, CBZ), 9-fluorenylmethyloxycarbonyl (Fmoc), p-methoxybenzyloxycarbonyl, p-nitrobenzyloxycarbonyl, tert-Butoxycarbonyl (BOC) and trifluoroacetyl; and

m is a metal ion selected from the list of alkali metal ions, alkaline earth metal ions and transition metal ions.

2. The method of claim 1, wherein R¹Is tert-Butoxycarbonyl (BOC).

3. The method of any one of claims 1 or 2, wherein R²Is tert-Butoxycarbonyl (BOC).

4. The method of any one of claims 1 to 3, wherein M is an alkali metal ion.

5. The method of any one of claims 1 to 4, wherein M is Na⁺。

6. The process according to any one of claims 1 to 5, comprising the following reaction steps:

a) deprotecting the compound of formula (III) in a solvent under acidic conditions;

b) adjusting to alkaline pH using a base;

c) adding a solution comprising the compound of formula (II) in a solvent;

d) a solution comprising a coupling agent in a solvent is added.

7. The process according to any one of claims 1 to 6, wherein the deprotection in step a) is carried out using hydrochloric acid.

8. A compound of formula (II)

Wherein R is¹As defined in any one of claims 1 to 2 and M is Na⁺。

9. The compound of formula (II) according to claim 8, which is sodium (S) -3- (tert-butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) propionate.

10. A pharmaceutical composition comprising a compound of formula (VI)

Technical Field

The present invention relates to a process for the preparation of pyrimidylcyclopentane compounds useful as intermediates in the preparation of AKT protein kinase inhibitors having therapeutic activity against diseases such as cancer.

Background

The protein kinase B/Akt enzymes are a group of serine/threonine kinases that are overexpressed in certain human tumors. International patent application WO 2008/006040 and U.S. patent No. 8,063,050 discuss a number of AKT inhibitors, including the compound (S) -2- (4-chlorophenyl) -1- (4- ((5R,7R) -7-hydroxy-5-methyl-6, 7-dihydro-5H-cyclopenta [ d ] pyrimidin-4-yl) piperazin-1-yl) -3- (isopropylamino) propan-1-one (ipapartib, GDC-0068) being explored in clinical trials for the treatment of various cancers.

Although the methods described in WO 2008/006040 and US 8,063,050 are useful for providing hydroxylated cyclopenta [ d ] pyrimidine compounds as AKT protein kinase inhibitors, there is a need for alternative or improved methods, including methods for the large scale manufacture of these compounds.

Summary of The Invention

The present invention provides processes for the preparation of compounds of formula (I)

Or a salt thereof, comprising a compound of formula (II)

With compounds of the formula (III)

In which R is¹、R²And M is as described herein.

Detailed Description

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below.

Unless otherwise indicated, the nomenclature used in this application is based on the IUPAC systematic nomenclature.

Unless otherwise indicated, any open valency appearing on a carbon, oxygen, sulfur, or nitrogen atom in the structures herein indicates the presence of hydrogen.

The term "one or more" when referring to the number of substituents refers to the range of substitution from one substituent to the highest possible number, i.e., one hydrogen is replaced by a substituent until all hydrogens are replaced by substituents.

The term "optional" or "optionally" means that the subsequently described event or circumstance may but need not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

The term "pharmaceutically acceptable salt" refers to salts that are not biologically or otherwise undesirable. Pharmaceutically acceptable salts include both acid addition salts and base addition salts.

The term "pharmaceutically acceptable acid addition salts" means salts formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, carbonic acid, phosphoric acid; and those pharmaceutically acceptable salts of organic acids selected from the aliphatic, cycloaliphatic, aromatic, araliphatic, heterocyclic, carboxylic and sulfonic classes of organic acids, such as formic acid, acetic acid, propionic acid, glycolic acid, gluconic acid, lactic acid, pyruvic acid, oxalic acid, malic acid, maleic acid, malonic acid, succinic acid, fumaric acid, tartaric acid, citric acid, aspartic acid, ascorbic acid, glutamic acid, anthranilic acid, benzoic acid, cinnamic acid, mandelic acid, pamoic acid, phenylacetic acid, methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid and salicylic acid.

The term "pharmaceutically acceptable base addition salts" denotes those pharmaceutically acceptable salts formed with organic or inorganic bases. Examples of acceptable inorganic bases include sodium, potassium, ammonium, calcium, magnesium, iron, zinc, copper, manganese, and aluminum salts. Salts obtained from pharmaceutically acceptable organic non-toxic bases include the salts of: primary, secondary and tertiary amines, substituted amines (including naturally occurring substituted amines), cyclic amines, and basic ion exchange resins, such as isopropylamine, trimethylamine, diethylamine, triethylamine, tripropylamine, ethanolamine, 2-diethylaminoethanol, trimethylamine, dicyclohexylamine, lysine, arginine, histidine, caffeine, procaine, hydrabamine, choline, betaine, ethylenediamine, glucosamine, methylglucamine, theobromine, purine, piperazine, piperidine, N-ethylpiperidine, and polyamine resins.

The stereochemical definitions and conventions used herein generally follow the codes of S.P. Parker, McGraw-Hill Dictionary of Chemical Terms (1984) McGraw-Hill Book Company, New York; and Eliel, E. and Wilen, S., "Stereochemistry of Organic Compounds", John Wiley & Sons, Inc., New York, 1994. In describing optically active compounds, the prefixes D and L or R and S are used to denote the absolute configuration of a molecule with respect to its chiral center. Substituents attached to the chiral center under consideration are ranked according to the Sequence Rule of Cahn, Ingold and Prelog (Sequence Rule). (Cahn et al Angew. chem. Inter. Edit.1966,5,385; reconnaissance 511). The prefixes D and L or (+) and (-) are used to designate the sign of plane-polarized light rotation achieved by the compound, where (-) or L designates the compound as left-handed. Compounds prefixed with (+) or D are dextrorotatory.

The term "stereoisomer" refers to a compound having the same molecular connectivity and bonding multiplicity, but differing in the arrangement of its atoms in space.

The term "chiral center" refers to a carbon atom bonded to four non-identical substituents. The term "chiral" means not capable of overlapping with mirror images, while the term "achiral" means that embodiments can overlap with their mirror images. Chiral molecules are optically active, i.e. they are capable of rotating the plane of plane polarized light.

The compounds of the invention may have one or more chiral centers and may exist as optically pure enantiomers, mixtures of enantiomers (such as, for example, racemates), optically pure diastereomers, mixtures of diastereomers, diastereomeric racemates or mixtures of diastereomeric racemates. As long as a chiral center is present in the chemical structure, all stereoisomers intended to be associated with that chiral center are encompassed by the present invention.

The term "enantiomer" means two stereoisomers of a compound that are non-superimposable mirror images of each other.

The term "diastereomer" refers to a stereoisomer that has two or more chiral centers and whose molecules are not mirror images of each other. Diastereomers have different physical properties, such as melting points, boiling points, spectral properties, and reactivities.

The term "diastereomeric excess" (de) denotes the diastereomeric purity, i.e. (diastereomer a-diastereomer B)/(diastereomer a + diastereomer B) (in area%).

The term "enantiomeric excess" (ee) denotes the enantiomeric purity, i.e. (enantiomer a-enantiomer B)/(enantiomer a + enantiomer B) (in area%).

The terms "halo" and "halogen" are used interchangeably herein and denote fluoro, chloro, bromo, or iodo.

The term "halide" denotes a halide, in particular fluoride, chloride, bromide or iodide.

The term "alkyl" denotes a monovalent straight or branched chain saturated hydrocarbon group having 1 to 12 carbon atoms. In particular embodiments, the alkyl group has from 1 to 7 carbon atoms, and in more particular embodiments, from 1 to 4 carbon atoms. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl.

The term "alkenyl" denotes a monovalent straight or branched hydrocarbon group having 2 to 7 carbon atoms and at least one double bond. In particular embodiments, the alkenyl group has 2 to 4 carbon atoms and at least one double bond. Examples of alkenyl groups include ethenyl, propenyl, prop-2-enyl, isopropenyl, n-butenyl and isobutenyl.

The term "alkynyl" denotes a monovalent straight or branched chain saturated hydrocarbon group having 2 to 7 carbon atoms, containing one, two or three triple bonds. In particular embodiments, alkynyl groups have 2 to 4 carbon atoms, including one or two triple bonds. Examples of alkynyl groups include ethynyl, propynyl, and n-butynyl.

The term "alkoxy" denotes a group of formula-O-R ', wherein R' is alkyl. Examples of alkoxy moieties include methoxy, ethoxy, isopropoxy, and tert-butoxy.

The term "haloalkyl" denotes an alkyl group wherein at least one hydrogen atom of the alkyl group has been replaced by the same or different halogen atoms, in particular fluorine atoms. Examples of haloalkyl include monofluoro, difluoro or trifluoromethyl, ethyl or propyl, such as 3,3, 3-trifluoropropyl, 2-fluoroethyl, 2,2, 2-trifluoroethyl, fluoromethyl or trifluoromethyl. The term "perhaloalkyl" denotes an alkyl group wherein all of the hydrogen atoms of the alkyl group have been replaced by the same or different halogen atoms.

The term "haloalkoxy" denotes an alkoxy group wherein at least one hydrogen atom of the alkoxy group has been replaced by the same or different halogen atom, in particular a fluorine atom. Examples of haloalkoxy include monofluoro, difluoro or trifluoromethoxy, ethoxy or propoxy, such as 3,3, 3-trifluoropropoxy, 2-fluoroethoxy, 2,2, 2-trifluoroethoxy, fluoromethoxy or trifluoromethoxy. The term "perhaloalkoxy" denotes an alkoxy group wherein all of the hydrogen atoms of the alkoxy group have been replaced by the same or different halogen atoms.

The term "cycloalkyl" denotes a monovalent saturated monocyclic or bicyclic hydrocarbon group having 3 to 10 ring carbon atoms. In particular embodiments, cycloalkyl represents a monovalent saturated monocyclic hydrocarbon group having 3 to 8 ring carbon atoms. Bicyclic means consisting of two saturated carbocyclic rings having one or more carbon atoms in common. Certain cycloalkyl groups are monocyclic. Examples of monocyclic cycloalkyl are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl. Examples of bicycloalkyl are bicyclo [2.2.1] heptanyl or bicyclo [2.2.2] octanyl.

The term "heterocycloalkyl" denotes a monovalent saturated or partially unsaturated monocyclic or bicyclic ring system having 3 to 9 ring atoms containing 1,2 or 3 ring heteroatoms selected from N, O and S, the remaining ring atoms being carbon. In particular embodiments, heterocycloalkyl is a monovalent saturated monocyclic ring system having 4 to 7 ring atoms that contains 1,2, or 3 ring heteroatoms selected from N, O and S, the remaining ring atoms being carbon. Examples of monocyclic saturated heterocycloalkyl are aziridinyl, oxiranyl, azetidinyl, oxetanyl, pyrrolidinyl, tetrahydrofuryl, tetrahydro-thienyl, pyrazolidinyl, imidazolidinyl, oxazolidinyl, isoxazolidinyl, thiazolidinyl, piperidinyl, tetrahydropyranyl, tetrahydrothiopyranyl, piperazinyl, morpholinyl, thiomorpholinyl, 1-dioxo-thiomorpholin-4-yl, azepanyl, diazepanyl, homopiperazinyl or oxazepanyl (oxazepanyl). Examples of bicyclic saturated heterocycloalkyl are 8-aza-bicyclo [3.2.1] octyl, quinuclidinyl, 8-oxa-3-aza-bicyclo [3.2.1] octyl, 9-aza-bicyclo [3.3.1] nonyl, 3-oxa-9-aza-bicyclo [3.3.1] nonyl or 3-thia-9-aza-bicyclo [3.3.1] nonyl. Examples of partially unsaturated heterocycloalkyl groups are dihydrofuranyl, imidazolinyl, dihydro-oxazolyl, tetrahydro-pyridyl or dihydropyranyl.

The term "aryl" denotes a monovalent aromatic carbocyclic mono-or bicyclic ring system comprising 6 to 10 carbon ring atoms. Examples of aryl moieties include phenyl and naphthyl. A particular aryl group is phenyl.

The term "heteroaryl" denotes a monovalent aromatic heterocyclic mono-or bicyclic ring system having 5 to 12 ring atoms comprising 1,2, 3 or 4 heteroatoms selected from N, O and S, the remaining ring atomsAnd the seed is carbon. Examples of heteroaryl moieties include pyrrolyl, furanyl, thienyl, imidazolyl, oxazolyl, thiazolyl, triazolyl, oxadiazolyl, thiadiazolyl, tetrazolyl, pyridyl, pyrazinyl, pyrazolyl, pyridazinyl, pyrimidinyl, triazinyl, aza-azanylRadical diazaA group selected from the group consisting of an isoxazolyl, a benzofuranyl, an isothiazolyl, a benzothiophenyl, an indolyl, an isoindolyl, an isobenzofuranyl, a benzimidazolyl, a benzoxazolyl, a benzisoxazolyl, a benzothiazolyl, a benzisothiazolyl, a benzooxadiazolyl, a benzothiadiazolyl, a benzotriazolyl, a purinyl, a quinolyl, an isoquinolyl, a quinazolinyl, and a quinoxalinyl group.

"leaving group" refers to the portion of a first reactant in a chemical reaction that is displaced from the first reactant in the chemical reaction. Examples of leaving groups include, but are not limited to, hydrogen, halogen, hydroxyl, sulfhydryl, amino (e.g., -NRR, wherein R is independently alkyl, alkenyl, alkynyl, cycloalkyl, phenyl, OR heterocyclyl, and R is independently optionally substituted), silyl (e.g., -SiRRR, wherein R is independently alkyl, alkenyl, alkynyl, cycloalkyl, phenyl, OR heterocyclyl, and R is independently optionally substituted), -n (R) OR (wherein R is independently alkyl, alkenyl, alkynyl, cycloalkyl, phenyl, OR heterocyclyl, and R is independently optionally substituted), alkoxy (e.g., -OR, wherein R is independently alkyl, alkenyl, alkynyl, cycloalkyl, phenyl, OR heterocyclyl, and R is independently optionally substituted), thiol group (e.g., -SR, wherein R is independently alkyl, alkenyl, alkynyl, cycloalkyl, OR heterocyclyl), thiol group (e.g., -SR, wherein R is independently alkyl, alkenyl, alkynyl, cycloalkyl, OR heterocyclyl, OR a combination thereof, Phenyl or heterocyclyl, and R is independently optionally substituted), sulfonyloxy (e.g., -OS (O)1-2R, wherein R is independently alkyl, alkenyl, alkynyl, cycloalkyl, phenyl, or heterocyclyl, and R is independently optionally substituted), a sulfamate group (e.g., -os (o)1-2NRR, wherein R is independently alkyl, alkenyl, alkynyl, cycloalkyl, phenyl, or heterocyclyl, and R is independently optionally substituted), a carbamate group (e.g., -oc (o)2NRR, wherein R is independently alkyl, alkenyl, alkynyl, cycloalkyl, phenyl, or heterocyclyl, and R is independently optionally substituted), and a carbonate group (e.g., -oc (o)2R, wherein R is independently alkyl, alkenyl, alkynyl, cycloalkyl, phenyl, or heterocyclyl, and R is independently optionally substituted). Exemplary carbonate groups include t-butyl carbonate. Exemplary sulfonyloxy groups include, but are not limited to, alkylsulfonyloxy (e.g., methylsulfonyloxy (methanesulfonate) and trifluoromethylsulfonyloxy (trifluoromethanesulfonate)) and arylsulfonyloxy (e.g., p-toluenesulfonyloxy (toluenesulfonate) and p-nitrobenzenesulfonyloxy (p-nitrobenzenesulfonate)). Other examples of leaving groups include substituted and unsubstituted amino groups such as amino, alkylamino, dialkylamino, hydroxyamino, alkoxyamino, N-alkyl-N-alkoxyamino, acylamino, sulfonylamino, t-butoxy and the like.

The term "protecting group" means a group that selectively blocks a reactive site in a polyfunctional compound so that a chemical reaction can proceed selectively at another unprotected reactive site, under the meaning conventionally associated with it in synthetic chemistry. The protecting group may be removed at an appropriate point. Exemplary protecting groups are amino protecting groups, carboxyl protecting groups, or hydroxyl protecting groups.

The term "amino protecting group" denotes a group intended to protect an amino group, and includes benzyl, benzyloxycarbonyl (benzyloxycarbonyl, CBZ), Fmoc (9-fluorenylmethyloxycarbonyl), p-methoxybenzyloxycarbonyl, p-nitrobenzyloxycarbonyl, t-Butoxycarbonyl (BOC), and trifluoroacetyl. Other examples of such Groups are found in t.w.greene and p.g.m.wuts, "Protective Groups in Organic Synthesis", 2 nd edition, John Wiley & Sons, inc., New York, NY,1991, chapter 7; haslam, "Protective Groups in Organic Chemistry", edited by J.G.W.McOmie, Plenum Press, New York, NY,1973, Chapter 5; and T.W.Greene, "Protective Groups in Organic Synthesis", John Wiley and Sons, New York, NY, 1981. The term "protected amino" refers to an amino group substituted with an amino protecting group. A specific example of an amino protecting group is tert-Butoxycarbonyl (BOC).

The term "deprotection/deprotection" refers to the process employed to remove a protecting group after completion of a selective reaction. Deprotecting agents include acids, bases or hydrogen, especially potassium or sodium carbonate, lithium hydroxide in alcoholic solution, zinc in methanol, acetic acid, trifluoroacetic acid, palladium catalyst or boron tribromide. A particular deprotection reagent is hydrochloric acid.

The term "buffer" means an excipient that stabilizes the pH of the formulation. Suitable buffers are well known in the art and can be found in the literature. Specific pharmaceutically acceptable buffers include histidine buffers, arginine buffers, citrate buffers, succinate buffers, acetate buffers, and phosphate buffers. Independent of the buffer used, the pH can be adjusted with acids or bases known in the art, such as hydrochloric acid, acetic acid, phosphoric acid, sulfuric acid and citric acid, sodium hydroxide and potassium hydroxide.

The term "alkali metal" refers to chemical elements of group 1 of the periodic table, i.e., lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). Specific examples of alkali metals are Li, Na and K, most particularly Na.

The term "alkaline earth metal" refers to chemical elements of group 2 of the periodic table, i.e., beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). Specific examples of alkaline earth metals are Mg and Ca.

The term "transition metal" denotes a chemical element whose atoms have an incomplete d-sub-shell (dsub-shell).

Abbreviations

Ac acetyl group

AcOH acetic acid

AN acetonitrile

BINAP 2,2 '-bis (diphenylphosphino) -1,1' -binaphthyl

BINAPHANE 1, 2-BIS [4, 5-dihydro-3H-BINAPHTHO (1,2-c:2',1' -e) PHOSPHAPINO ] BENZENE

BIPHEMP (6,6 '-dimethylbiphenyl-2, 2' -diyl) bis (diphenyl-phosphine)

BOC tert-butoxycarbonyl

(Boc)₂Di-tert-butyl O dicarbonate

CBS Keli-Bakeshi-chaita

(Corey-Bakshi-Shibata) catalyst

CBZ Phenylmethyloxycarbonyl, benzyloxycarbonyl

COD 1, 5-cyclooctadiene

CPME Cyclopentylmethyl Ether

de diastereomeric excess

DIPEA diisopropylethylamine

DMAP dimethylaminopyridine

DMF N, N-dimethylformamide

DPEN 1, 2-diphenylethylenediamine

ee enantiomeric excess

Et Ethyl group

EtOAc ethyl acetate

Fmoc 9-fluorenylmethyloxycarbonyl

(2-furyl) -MeOBIPHP (6,6 '-dimethoxybiphenyl-2, 2' -diyl) bis [ bis (2-furyl) -phosphine ]

HAP harmful air pollutants

HBTU N, N, N ', N' -tetramethyl-O- (1H-benzotriazol-1-yl) urea hexafluorophosphate

iBu isobutyl group

ICM International coordination conference

IPC in-process control

iPr isopropyl group

iPr-DUPHOS 1, 2-bis (2, 5-di-isopropylphospholanyl) benzene

Me methyl group

MeOBIPHEP (6,6 '-dimethoxybiphenyl-2, 2' -diyl) bis (diphenyl-phosphine)

MES 2- (N-morpholino) ethanesulfonic acid

MTBE methyl tert-butyl ether

NAD nicotinamide adenine dinucleotide

NADP phosphate Nicotinamide adenine dinucleotide

nBu n-butyl

NEM N-ethylmorpholine

n-propyl group of nPr

OAc acetate

PBS potassium dihydrogen phosphate buffer solution

pCym para-cymene

PDE allowances daily Exposure

Ph phenyl

pTol p-tolyl radical

pTol-Binap 2,2 '-bis (di-p-tolylphosphino) -1,1' -binaphthyl

S/C substrate to catalyst molar ratio

T3P propylphosphonic anhydride

tBu tert-butyl

t-BuOK Potassium tert-butoxide

TEA Triethylamine

TFA trifluoroacetate

THF tetrahydrofuran

TMBTP 2,2', 5, 5' -tetramethyl-4, 4 '-bis (diphenylphosphino) -3, 3' -bithiophene

TPA tri (n-propyl) amine

Xyl 3, 5-dimethylphenyl

3,5-Xyl,4-MeO-MeOBIPHEP (6,6 '-dimethoxybiphenyl-2, 2' -diyl) bis [ bis (3, 5-dimethyl-4-methoxy-phenyl) phosphine ]

3,5-Xyl-BINAP 2,2 '-bis [ di (3, 5-xylyl) phosphine ] -1,1' -binaphthyl

3,5-Xyl-MeOBIPHEP (6,6 '-dimethoxybiphenyl-2, 2' -diyl) bis [ bis (3, 5-dimethylphenyl) phosphine ]

The present invention provides a process for the preparation of a compound of formula (I) or a salt thereof, comprising a coupling reaction of a compound of formula (II) with a compound of formula (III), wherein R¹、R²And M are as described herein (scheme 1 below).

Another aspect of the present invention relates to a method for producing a compound of formula (II), which comprises asymmetrically hydrogenating a compound of formula (IV) using a metal complex catalyst (C) (scheme 1 below).

One aspect of the present invention relates to a method for the manufacture of a compound of formula (III) comprising an oxidoreductase-catalyzed asymmetric reduction of a compound of formula (V) (scheme 1 below).

Another aspect of the present invention relates to a process for the manufacture of a compound of formula (VI) or a pharmaceutically acceptable salt thereof, wherein the compound of formula (I) is deprotected (scheme 1 below).

Scheme 1

In one embodiment of the invention, R¹Is an amino protecting group selected from the list of benzyl, benzyloxycarbonyl (benzyloxycarbonyl, CBZ), 9-fluorenylmethyloxycarbonyl (Fmoc), p-methoxybenzyloxycarbonyl, p-nitrobenzyloxycarbonyl, tert-Butoxycarbonyl (BOC) and trifluoroacetyl.

In a particular embodiment of the invention, R¹Is tert-Butoxycarbonyl (BOC).

In one embodiment of the invention, R²Is an amino protecting group selected from the list of benzyl, benzyloxycarbonyl (benzyloxycarbonyl, CBZ), 9-fluorenylmethyloxycarbonyl (Fmoc), p-methoxybenzyloxycarbonyl, p-nitrobenzyloxycarbonyl, tert-Butoxycarbonyl (BOC) and trifluoroacetyl.

In a particular embodiment of the invention, R²Is tert-Butoxycarbonyl (BOC).

In one embodiment of the present invention, M is a metal ion selected from the list of alkali metal ions, alkaline earth metal ions and transition metal ions.

In a particular embodiment of the invention, M is a metal ion, in particular an alkali metal ion, an alkaline earth metal ion or a transition metal ion, with the proviso that it is not K⁺。

In a particular embodiment of the invention, M is an alkali metal ion.

In a particular embodiment of the invention, M is Li⁺、K⁺Or Na⁺。

In a particular embodiment of the invention, M is not K⁺。

In a most specific embodiment of the invention, M is Na⁺。

WO 2008/006040 discloses amino acids of formula (II-pa) wherein R is⁶And R⁹Various alternatives are possible and t is 0 to 4.

The process disclosed therein for the manufacture of compounds of formula (II-pa) involves a) a diastereoselective reaction of an alkylamine with a 2-arylacrylate to produce a racemic mixture or b) the asymmetric addition of alkoxymethylamine to a 2-phenylacetate containing a suitable chiral auxiliary. Neither process involves asymmetric hydrogenation, but addition reactions. Thus, both methods require additional steps for addition, cleavage and separation of the aids.

The synthesis according to method a) above proceeds by forming a racemic ester intermediate which is further hydrolyzed to the racemic acid, coupled with a chiral auxiliary (only in the form of, for example, the S enantiomer) to yield a 50:50 mixture of diastereoisomeric R-amino acids/S-auxiliary and S-amino acids/S-auxiliary. The diastereomers have to be separated by chromatography. The yield of the desired S-S intermediate was only 38%. In addition, the S-S intermediate must be hydrolyzed to provide the S-II acid (with the loss of the chiral auxiliary of the other chiral component). This procedure is tedious and inefficient because 72% of the material is lost in one step. In summary, the diastereoselective addition of amines and acrylates exhibits a lack of stereoselectivity and therefore the inherent problem of having to separate racemic mixtures by, for example, chromatography. Thus, the yield is at least 100% lower compared to the stereoselective sequence.

Furthermore, the asymmetric addition to the intermediate containing the chiral auxiliary (method b) above) requires additional steps for addition, cleavage and separation of the auxiliary. The precursors in the synthesis of the targeted acid are combined with a chiral auxiliary and the resulting intermediate is coupled with alkoxymethylamine. The product, if not consisting of a 1:1 mixture, at best consists of a slightly enriched mixture of diastereoisomers R/S and S/S, which must be further processed as mentioned above to isolate the (S) -isomer of the compound of formula (II-pa) in at best moderate yield.

Thus, better stereoselectivity is provided for the preparation of the compound of formula (II), thereby allowing to avoid subsequent chiral chromatography; fewer reaction steps are required; provide higher yields; and thus more efficient, greener and less costly improved methods are in unmet need.

The inventors of the present invention have found a novel process for the manufacture of a compound of formula (II) comprising asymmetric hydrogenation of a compound of formula (IV) using a metal complex catalyst (C).

This novel process for the manufacture of the compound of formula (II) is characterized by a number of related benefits compared to processes known in the art:

introduction of highly stereoselective reactions in the synthesis;

avoiding the use of chiral chromatography for subsequent purification;

a reduction in the number of reaction steps;

the overall yield is improved;

the overall reaction is more efficient, greener and less costly.

The specific metal complex catalysts of the present invention have been found to be much more efficient and much more active and selective than other known catalysts in the following sense: under similar reaction conditions (i.e., no additive), substrate to catalyst molar ratios (S/C) of as much as 10' 000 can be employed, while other known catalysts need to be used at S/C of 200-250. Thus, 40-50 times less catalyst usage has a substantial impact on efficiency, cost, and greenness.

Certain known catalysts require large amounts of LiBF₄As an additive (up to 5.8 mol% relative to the hydrogenation substrate, up to 100 molar equivalents relative to the catalyst) to increase the catalyst activity. High LiBF₄Is disadvantageous for industrial processes because of the presence of this large amount of fluoride ions (up to the hydrogenation substrate)23.2%) caused problems with corrosion steel pressure reactors when scaled up. On the other hand, even in LiBF₄With the additive, the catalyst also failed to reach the activity of our novel catalyst (e.g., up to S/C10' 000).

Homogeneous catalytic reactions, such as asymmetric hydrogenation, for example, as known in the art, require extremely laborious work-up procedures involving many cycles of extraction and concentration of the solution. Furthermore, asymmetric hydrogenation as known in the art requires removal of the metal catalyst with large amounts (up to 6 wt%; up to 193 times the weight of the catalyst relative to the hydrogenation substrate) of a scavenger (e.g., a thiol resin). Such removal of ruthenium contaminants using scavenger resins has not been easy to date and is quite expensive. Furthermore, the ruthenium content is only partially reduced (e.g., to about 50ppm) and proceeds to the next step, thus increasing the likelihood of byproduct formation. This increases material and labor costs and opens up discussions about potential impurities.

In summary, known methods for purifying and separating hydrogenation products from catalysts and additives are inefficient.

In contrast, the process according to the invention provides salts of the compounds of formula (II) which precipitate directly from the hydrogenation mixture and can be filtered off easily. Such isolation and purification of the hydrogenation product provides high yields (> 94%) with an ee of 100% and a ruthenium content below the detection limit of 5 ppm. The treatment of the asymmetric hydrogenation reaction product as discovered by the present inventors is therefore substantially simpler, cheaper and more applicable than conventional processes.

One aspect of the present invention relates to a compound of formula (II)

Wherein R is¹And M is as defined herein.

One aspect of the present invention relates to a compound of formula (II) which is sodium (S) -3- (tert-butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) propionate.

One aspect of the present invention relates to a process for the manufacture of a compound of formula (II)

Which comprises reacting a compound of the formula (IV) with a metal complex catalyst (C)

Asymmetric hydrogenation, wherein R¹And M is as defined herein.

In one embodiment of the present invention, the metal complex catalyst (C) is a ruthenium complex catalyst.

In one embodiment of the present invention, the ruthenium complex catalyst comprises ruthenium characterized by an oxidation number of II.

In one embodiment of the present invention, the ruthenium complex catalyst comprises a chiral phosphine ligand (D).

In one embodiment of the present invention, the ruthenium complex catalyst comprises ligands, in particular neutral ligands (L) and/or anionic ligands (Z).

Examples of neutral ligands (L) are olefins such as ethylene or propylene, cyclooctene, 1, 3-hexadiene, norbornadiene, 1, 5-cyclooctadiene, benzene, hexamethylbenzene, 1,3, 5-trimethylbenzene and p-cymene, or also solvents such as tetrahydrofuran, dimethylformamide, acetonitrile, benzonitrile, acetone, toluene and methanol.

An example of an anionic ligand (Z) is acetate (CH)₃COO-), trifluoroacetate (CF)₃COO-)、η⁵-2, 4-pentadienyl eta⁵2, 4-dimethyl-pentadienyl and halide ions, such as fluoride, chloride, bromide or iodide.

If the ruthenium complex catalyst is charged, it also contains a non-coordinating anion (Y). Examples of non-coordinating anions (Y) are halides, such as fluoride, chloride, bromide or iodide, BF₄-、ClO₄-、SbF₆-、PF₆-, B (phenyl)₄-, B (3, 5-bis-trifluoromethyl-phenyl)₄-、CF₃SO₃-and C₆H₅SO₃-。

The ruthenium complex catalyst may optionally be further coordinated to a Lewis acid (Lewis acid), such as AlCl₃。

In one embodiment of the invention, the ruthenium complex catalyst is selected from compounds of formula (C1), (C2), or (C3):

Ru(Z)₂D (C1)

[Ru(Z)_2-p(D)(L)_m](Y)_p (C2)

Ru(E)(E')CD)(F) (C3)

wherein:

d is a chiral phosphine ligand;

l is a neutral ligand selected from: c_2-7Alkene, cyclooctene, 1, 3-hexadiene, norbornadiene, 1, 5-cyclooctadiene, benzene, hexamethylbenzene, 1,3, 5-trimethylbenzene, p-cymene, tetrahydrofuran, dimethylformamide, acetonitrile, benzonitrile, acetone, toluene, and methanol;

z is an anionic ligand selected from: hydride, fluoride, chloride, bromide,. eta⁵-2, 4-pentadienyl eta⁵-2, 4-dimethyl-pentadienyl or a radical A-COO^-Provided that when two Z's are attached to the Ru atom, they may be the same or different;

a is C_1-7Alkyl radical, C_1-7Haloalkyl, aryl or haloaryl;

y is a non-coordinating anion selected from: fluoride ion, chloride ion, bromide ion, BF₄ ^-、ClO₄ ^-、SbF₆ ^-、PF₆ ^-B (phenyl)₄ ^-B (3, 5-bis-trifluoromethyl-phenyl)₄ ^-、CF₃SO₃ ^-And C₆H₅SO₃ ^-；

F is an optionally chiral diamine;

e and E' are both halide ions, or E is hydrogenAn anion, and E' is BH₄ ^-；

m is 1,2, 3 or 4:

p is 1 or 2.

In a particular embodiment of the invention, the ruthenium complex catalyst is selected from compounds of formula (C1) or (C2), wherein Z, D, L, Y, m and p are as described herein.

In a particular embodiment of the invention, the ruthenium complex catalyst is selected from compounds of formula (C1), wherein Z and D are as described herein.

In a particular embodiment of the invention, the ruthenium complex catalyst is Ru (Z)₂D, wherein Z and D are as described herein.

In a particular embodiment of the invention, the ruthenium complex catalyst is selected from compounds of formula (C2), wherein Z, D, L, Y, m and p are as described herein.

In a particular embodiment of the invention, the ruthenium complex catalyst is selected from compounds of formula (C3), wherein E, E', D and F are as described herein.

In a particular embodiment of the invention, the anionic ligands (Z) are independently selected from chloride, bromide, iodide, OAc and TFA.

In a particular embodiment of the invention, the anionic ligand (Z) is A-COO^-。

In a particular embodiment of the invention, A is-CF₃。

In a particular embodiment of the invention, the anionic ligand (Z) is Trifluoroacetate (TFA).

In a particular embodiment of the invention, the neutral ligands (L) are independently selected from benzene (C)₆H₆) P-cymene (pCym) and Acetonitrile (AN).

In a particular embodiment of the invention, the neutral ligand (L) is benzene (C)₆H₆)。

In a particular embodiment of the invention, the non-coordinating anion (Y) is selected from the group consisting of chloride, bromide, iodide and BF₄ ^-。

In a particular embodiment of the invention, the non-coordinating anion(s) ((s))Y) is BF₄ ^-。

In a particular embodiment of the invention, m is 1 or 4.

In a particular embodiment of the invention, m is 1.

In a particular embodiment of the invention, m is 4.

In a particular embodiment of the invention, p is 1.

In a particular embodiment of the invention, p is 2.

In a particular embodiment of the invention, E and E' are both chloride;

in a particular embodiment of the invention, the chiral diamine F is (1S,2S) -1, 2-diphenylethylenediamine (S, S-DPEN).

In a particular embodiment of the invention, the ruthenium complex catalyst is coordinated to a Lewis acid, in particular AlCl₃。

In one embodiment of the invention, the chiral phosphine ligand D is selected from compounds of formulae (D1) to (D12):

wherein:

R¹¹is C_1-7Alkyl radical, C_1-7Alkoxy, benzyloxy, hydroxy or C_1-7alkyl-C (O) O-;

R¹²and R¹³Each independently is hydrogen, C_1-7Alkyl radical, C_1-7Alkoxy or di (C)_1-7Alkyl) amino; or

R bound to the same phenyl group¹¹And R¹²Or R attached to the same phenyl group¹²And R¹³Together are-X- (CH)₂)_r-Y-, wherein X is-O-or-C (O) O-, Y is-O-, -N (lower alkyl) -or-CF₂-, and r is an integer of 1 to 6; or

Two R¹¹Together are-O- (CH)₂)_s-O-or O-CH (CH)₃)-(CH₂)_s-CH(CH₃) -O-wherein s isAn integer of 1 to 6; or

R¹¹And R¹²Or R¹²And R¹³Together with the carbon atom to which they are attached form a naphthyl, tetrahydronaphthyl or dibenzofuran ring;

R¹⁴and R¹⁵Each independently is C_1-7Alkyl radical, C_3-8Cycloalkyl, phenyl, naphthyl, or heteroaryl, optionally substituted with 1 to 7 substituents independently selected from the group consisting of: c_1-7Alkyl radical, C_1-7Alkoxy, di (C)_1-7Alkyl) amino, morpholinyl, phenyl, tri (C)_1-7Alkyl) silyl, C_1-7Alkoxycarbonyl, hydroxycarbonyl, hydroxysulfonyl, (CH)₂)_t-OH and (CH)₂)_t-NH₂Wherein t is an integer from 1 to 6;

R¹⁶is C_1-7An alkyl group;

R¹⁷is C_1-7An alkyl group; and is

R¹⁸Independently is aryl, heteroaryl, C_3-8Cycloalkyl or C_1-7An alkyl group.

In a particular embodiment of the invention, the chiral phosphine ligand (D) is selected from compounds of formula (D1), wherein R is¹¹To R¹⁵As described herein.

In a particular embodiment of the invention, the chiral phosphine ligand (D) is selected from (R) -3,5-Xyl-BINAP, (R) -BINAP, (S) -2-furyl-MeOBIPHEP, (S) -BINAP, (S) -BINAPHANE, (S) -MeOBIPHEPEP, (S) -pTol-BINAP), (S) -TMBTP and (S, S) -iPr-DUPHOS.

In a particular embodiment of the invention, the chiral phosphine ligand (D) is selected from the group consisting of (S) -BIPHEMP, (S) -BINAP and (S) -MeOBIPHEP.

In a particular embodiment of the invention, the chiral phosphine ligand (D) is (S) -BINAP.

In a particular embodiment of the invention, the chiral phosphine ligand (D) is (S) -2,2 '-bis (diphenylphosphino) -1,1' -binaphthyl.

In a particular embodiment of the invention, the chiral phosphine ligand (D) is

In a particular embodiment of the invention, the ruthenium complex catalyst is selected from the group of:

Ru(TFA)₂((R)-3,5-Xyl-BINAP)、

Ru(OAc)₂((S) -2-furyl-MeOBIPHEP),

Ru(OAc)₂((S)-BINAP)、

[Ru(OAc)₂((S)-BINAP)]AlCl₃、

Ru(TFA)₂((S)-BINAP)、

Ru(TFA)₂((S)-BINAPHANE)、

Ru(TFA)₂((S)-BIPHEMP)、

Ru(OAc)₂((S)-MeOBIPHEP)、

Ru(TFA)₂((S)-TMBTP)、

Ru(TFA)₂((S,S)-iPr-DUPHOS)、

[Ru((R)-BINAP)(pCym)(AN)](BF₄)₂、

[RuBr((S)-BINAP)(C₆H₆)]Br、

[RuCl((S)-BINAP)(C₆H₆)]BF₄、

[RuCl((S)-BINAP)(C₆H₆)]Cl、

[RuI((S)-BINAP)(C₆H₆)]I、

[Ru((S)-BINAP)(AN))₄](BF₄)₂And

RuCl₂((S)-pTol-BINAP)(S,S-DPEN)。

in a particular embodiment of the invention, the ruthenium complex catalyst is selected from the group of:

Ru(TFA)₂((R)-3,5-Xyl-BINAP)、

Ru(OAc)₂((S) -2-furyl-MeOBIPHEP),

Ru(OAc)₂((S)-BINAP)、

[Ru(OAc)₂((S)-BINAP)]AlCl₃、

Ru(TFA)₂((S)-BINAP)、

Ru(TFA)₂((S)-BINAPHANE)、

Ru(TFA)₂((S)-BIPHEMP)、

Ru(OAc)₂((S)-MeOBIPHEP)、

Ru(TFA)₂((S)-TMBTP)、

Ru(TFA)₂((S,S)-iPr-DUPHOS)、

[Ru((R)-BINAP)(pCym)(AN)](BF₄)₂、

[RuBr((S)-BINAP)(C₆H₆)]Br、

[RuCl((S)-BINAP)(C₆H₆)]BF₄、

[RuI((S)-BINAP)(C₆H₆)]I、

[Ru((S)-BINAP)(AN))₄](BF₄)₂And

RuCl₂((S)-pTol-BINAP)(S,S-DPEN)。

in a particular embodiment of the invention, the ruthenium complex catalyst is a compound of formula (C1) selected from the group of:

Ru(TFA)₂((R)-3,5-Xyl-BINAP)、

Ru(OAc)₂((S) -2-furyl-MeOBIPHEP),

Ru(OAc)₂((S)-BINAP)、

[Ru(OAc)₂((S)-BINAP)]AlCl₃、

Ru(TFA)₂((S)-BINAP)、

Ru(TFA)₂((S)-BINAPHANE)、

Ru(TFA)₂((S)-BIPHEMP)、

Ru(OAc)₂((S)-MeOBIPHEP)、

Ru(TFA)₂((S) -TMBTP) and

Ru(TFA)₂((S,S)-iPr-DUPHOS)。

in a particular embodiment of the invention, the ruthenium complex catalyst is a compound of formula (C2) selected from the group of:

[Ru((R)-BINAP)(pCym)(AN)](BF₄)₂、

[RuBr((S)-BINAP)(C₆H₆)]Br、

[RuCl((S)-BINAP)(C₆H₆)]BF₄、

[RuCl((S)-BINAP)(C₆H₆)]Cl、

[RuI((S)-BINAP)(C₆H₆)]i and

[Ru((S)-BINAP)(AN)₄](BF₄)₂。

in a particular embodiment of the invention, the ruthenium complex catalyst is a compound of formula (C3), in particular RuCl₂((S)-pTol-BINAP)(S,S-DPEN))。

In a particular embodiment of the invention, the ruthenium complex catalyst is ru (tfa)2((S) -BINAP).

In a particular embodiment of the invention, the ruthenium complex catalyst is [ RuCl (S-BINAP) (C)₆H₆)]Cl。

In a particular embodiment of the invention, the ruthenium complex catalyst is not [ RuCl (S-BINAP) (C)₆H₆)]Cl。

In a particular embodiment of the invention, the asymmetric hydrogenation of the compound of formula (IV) is carried out in a solvent selected from alcohols, hydrocarbons, chlorinated hydrocarbons, fluorinated and polyfluorinated aliphatic or aromatic hydrocarbons, supercritical or liquid carbon dioxide, THF, water or mixtures thereof.

Specific solvents for asymmetric hydrogenation are alcohols, chlorinated hydrocarbons and THF.

Specific solvents for asymmetric hydrogenation are selected from MeOH, EtOH, i-PrOH, EtOH/cyclopentylmethyl ether, EtOH/CH₂Cl₂、EtOH/EtOAc、EtOH/THF、EtOH/H₂O、CH₂Cl₂And list of THF.

The most specific solvent for asymmetric hydrogenation is ethanol (EtOH).

The solvents can be used alone or in the form of mixtures of the solvents mentioned above.

In a particular embodiment of the invention, the asymmetric hydrogenation of the compound of the formula (IV) is carried out at a concentration of the compound of the formula (IV) of from 1 to 50% by weight, in particular 5%, 10%, 20% or 30% by weight.

In a particular embodiment of the invention, the asymmetric hydrogenation of the compound of the formula (IV) is carried out at a concentration of from 10 to 25% by weight of the compound of the formula (IV).

It has surprisingly been found that in special cases the addition of certain additives improves the asymmetric hydrogenation of the compound of formula (IV). It is hypothesized that the activity and stability of the ruthenium catalyst is substantially improved and, therefore, the amount of catalyst required is reduced. The use of lower amounts of catalyst results in simplified processing and reduced costs.

In a particular embodiment of the invention, the asymmetric hydrogenation of the compound of formula (IV) also comprises one or more compounds selected from the group consisting of LiBF₄、LiPF₆、LiO₃SCF₃、NaCl、NaBr、NaI、KCl、KBr、KI、LiCl、LiBr、LiI、HBF₄、HCl、HBr、H₂SO₄And CH₃SO₃H list of additives.

In a particular embodiment of the invention, the asymmetric hydrogenation of the compound of formula (IV) does not comprise LiBF₄、LiPF₆Or LiO₃SCF₃As an additive. In view of the highly corrosive nature of the fluoride ion-containing additives, they are difficult to handle and are therefore not preferred.

In a particular embodiment of the invention, the asymmetric hydrogenation of the compound of formula (IV) further comprises one or more additives selected from the list of NaCl, NaBr, KCl, KBr, HCl and HBr.

In a particular embodiment of the invention, the asymmetric hydrogenation of the compound of formula (IV) also comprises one or more compounds selected from the group consisting of LiBF₄、HBF₄、HCl、H₂SO₄And CH₃SO₃H list of additives.

In a particular embodiment of the invention, the asymmetric hydrogenation of the compound of formula (IV) also comprises one or more compounds selected from the group consisting of LiBF₄、NaCl、NaBr、LiCl、LiBr、LiI、HBF₄、HCl、HBr、H₂SO₄And CH₃SO₃H list of additives.

In a particular embodiment of the invention, the asymmetric hydrogenation of the compound of formula (IV) is carried out with hydrogen as the hydrogen source.

In a particular embodiment of the invention, the asymmetric hydrogenation of the compound of the formula (IV) is carried out under a hydrogen pressure of from 1 to 150 bar, in particular from 10 to 30 bar, most particularly from 17 to 21 bar.

In a particular embodiment of the invention, the asymmetric hydrogenation of the compound of the formula (IV) is carried out at a temperature of from 10 to 120 ℃, in particular from 20 to 90 ℃.

In a particular embodiment of the invention, the asymmetric hydrogenation of the compound of formula (IV) is carried out during a period of from 5 to 30 hours, in particular from 6 to 25 hours, more in particular from 6 to 23 hours.

In a particular embodiment of the invention, the asymmetric hydrogenation of the compound of formula (IV) is carried out at a substrate/catalyst ratio (S/C) of from 5 to 100 ' 000, in particular from 100 to 15 ' 000, most in particular from 100 to 10 ' 000.

In a particular embodiment of the invention, the asymmetric hydrogenation of the compound of the formula (IV) is carried out batchwise.

In a particular embodiment of the invention, the asymmetric hydrogenation of the compound of formula (IV) is carried out in a continuous manner.

One aspect of the present invention relates to a process for the manufacture of a compound of formula (II)

Which comprises reacting a compound of the formula (IV) with a metal complex catalyst (C)

Asymmetric hydrogenation followed by addition of formula C to the hydrogenation reaction mixture_1-7Alcohol solutions of alkyl-OM metal alkoxides to form salts, wherein R¹And M is as defined herein.

One aspect of the present invention relates to a process for the manufacture of a compound of formula (II) comprising asymmetric hydrogenation of a compound of formula (IV) using a metal complex catalyst (C), followed by addition of formula C to the hydrogenation reaction mixture without prior isolation or purification of the acid intermediate_1-7Alcohol solutions of alkyl-OM metal alkoxides to form salts, wherein R¹And M is as defined herein.

In a particular embodiment of the invention, the metal alkoxide employed in the salt forming step is MeOM, EtOM, iPrOM, nPrOM, nBuOM, iBuOM or tBuOM, most particularly EtOM.

In a particular embodiment of the invention, the alcohol used as solvent in the salt-forming step is C_1-7alkyl-OH, more particularly MeOH, EtOH, iPrOH, nPrOH, nBuOH, iBuOH or tBuOH, most particularly EtOH.

One aspect of the present invention relates to a process for the manufacture of a compound of formula (II) comprising asymmetric hydrogenation of a compound of formula (IV) using a metal complex catalyst (C), followed by salt formation by addition of an ethanolic solution of sodium ethoxide to the hydrogenation reaction mixture.

The compounds of formula (IV) can be prepared according to methods known to those skilled in the art. One particular general method for preparing the compound of formula (IV) is depicted in scheme 2. For a more detailed description of the individual reaction steps, see the examples section below.

Scheme 2

Reacting a compound of formula (IVa) (wherein R³Is optionally substituted C_1-7Alkyl, especially ethyl) with the compound HCO₂R⁴(wherein R is⁴Is an optionally substituted C1-7 alkyl group, particularly ethyl) under basic conditions to form a compound of formula (IVb). A compound of formula (IVb) with an amine HN (isopropyl) R⁵(wherein R is⁵Is hydrogen, C_1-7Alkyl or amino protecting groups) by further condensationTo form the compound of formula (IVc). When in the compound of formula (IVc) R⁵When hydrogen, the amine may be additionally protected to form a protected compound of formula (IVc) (e.g. wherein R is⁵Is an amino protecting group such as Boc). Hydrolysis of the ester of compound (IVc) provides the compound of formula (IV).

The ruthenium complex catalysts of the invention can in principle be prepared in a manner known per se. They can be prepared, for example, according to B.Heiser et al Tetrahedron: Asymmetry 1991,2, 51; or N.Feiken et al, Organometallics 1997,16, 537; or j. -p.genet, acc.chem.res.2003,36,908; or k.mashima et al, j.org.chem.1994,53,3064; angew. chem. int. Ed.1998,37, 1703-; or m.p. fleming et al, US 6,545,165B1 and references cited therein; and in particular for o.briel et al, Catalysis of Organic Reactions, CRC Press, Boca Raton,2009 of ferrocene-based Ru complexes, directly isolated or used (prepared in situ), the disclosures of all of these documents are incorporated herein by reference in their entirety for all purposes.

[Ru(TFA)₂((S)-BINAP)]The synthesis of (D) is disclosed in B.Heiser et al, Tetrahedron: Asymmetry 1991,2, 51.

The ruthenium complex catalyst can be prepared in situ, i.e., just prior to use and without separation. The solution in which such catalysts are prepared may already contain the substrate for enantioselective hydrogenation or the solution may be mixed with the substrate just before the hydrogenation reaction is initiated.

WO 2008/006040 discloses 5-methyl-6, 7-dihydro-5H-cyclopenta [ d ] of formula (71)]Pyrimidin-7-ol and process for producing the same, wherein R⁵Various alternatives are possible.

In particular, WO 2008/006040 discloses the use of chiral catalysts (in the presence of hydrogen), coriolis-buckhsh-Chayote (CBS) catalysts, borohydride reducing agents (in the presence of chiral ligands) or achiral reducing agents (e.g. H)₂Pd/C), reacting 5-methyl-5, 6-dihydrocyclopenta [ d)]Asymmetric reduction of pyrimidin-7-one to (R) or (S) -5-methyl-6,7-dihydro-5H-cyclopenta [ d]Pyrimidin-7-ol.

The processes known in the art to produce compounds of formula (III) exhibit the inherent disadvantages that they require vigorous reaction conditions (e.g. high pressure), use heavy metals and chiral auxiliaries, and the diastereoselectivity obtained is only limited (i.e. 88% de), thus requiring additional purification steps.

The inventors of the present invention have found use in the manufacture of compounds wherein R²A novel enzymatic process for the compounds of formula (III) as described herein.

These novel processes for the manufacture of compounds of formula (III) according to the present invention are characterized by a number of associated benefits compared to processes as known in the art. The advantage of enzymatic reduction is its catalytic nature, avoiding the potentially extremely high diastereoselectivity and mild reaction conditions that would require subsequent resolution of the diastereoisomers formed. Furthermore, heavy metals and chiral auxiliaries are not required.

The enzymatic reduction of the invention simplifies the technical requirements, reduces the number and quantity of components and enables a higher space-time yield. The advantages of the present invention are exemplified by the improvement of the technology-related guidelines, such as increased substrate concentration (up to 25%), increased product concentration (up to 25%), decreased cofactor loading (down to 1/3000 for the compound of formula (V)), and simpler cofactor regeneration system with 2-propanol as the final reducing agent. The cofactor regeneration system with 2-propanol as the final reducing agent avoids secondary enzymes, reduces viscosity, avoids continuous neutralization of gluconic acid as an oxidation co-substrate, and allows continuous removal of acetone formed.

One aspect of the present invention relates to a process for the manufacture of a compound of formula (III)

Which comprises reacting a compound of formula (V) catalyzed by a redox enzyme

Asymmetric reduction, wherein R²As defined herein.

In one aspect of the invention, the oxidoreductase catalyzing the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is a ketoreductase.

In one aspect of the invention, the oxidoreductase catalyzes the asymmetric reduction of the compound of formula (V) to the compound of formula (III) with a diastereoselectivity of at least 95% diastereomeric excess (de), particularly with a diastereoselectivity of at least 98% de, more particularly with a diastereoselectivity of at least 99% de.

In one aspect of the invention, the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is catalyzed by an oxidoreductase in the presence of a cofactor.

In one aspect of the invention, the cofactor oxidized in the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is NADH or NADPH.

In one aspect of the invention, the cofactor oxidized in the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is regenerated in situ using enzyme-coupled cofactor regeneration (e.g. based on glucose and glucose dehydrogenase as the final reducing agent) or substrate-coupled regeneration (e.g. using a secondary alcohol as co-substrate).

In one aspect of the invention, the oxidized cofactor in the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is regenerated in situ by enzyme-coupled cofactor regeneration using glucose and glucose dehydrogenase as co-substrates.

In one aspect of the invention, the oxidized cofactor in the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is regenerated in situ by substrate coupled regeneration using a secondary alcohol as co-substrate.

In one aspect of the invention, the secondary alcohol used as co-substrate for the coupled regeneration of the substrate is selected from 2-propanol, 2-butanol, butane-1, 4-diol, 2-pentanol, pentane-1, 5-diol, 4-methyl-2-pentanol, 2-hexanol, hexane-1, 5-diol, 2-heptanol or 2-octanol, in particular 2-propanol.

Particularly suitable is the use of 2-propanol for the regeneration of the cofactor under the same enzymes that also catalyze the target reaction and the continuous removal of the acetone formed.

In one aspect of the invention, the oxidoreductase catalyzing the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is a diastereoselective NADPH-dependent oxidoreductase.

In one aspect of the invention, the oxidoreductase catalyzing the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is a diastereoselective NADPH-dependent oxidoreductase selected from the list of:

KRED-NADPH-111 (from Codexis Inc., Redwood City, CA, USA),

KRED-NADPH-112 (from Codexis Inc., Redwood City, CA, USA),

KRED-NADPH-113 (from Codexis Inc., Redwood City, CA, USA),

KRED-NADPH-114 (from Codexis Inc., Redwood City, CA, USA),

KRED-NADPH-115 (from Codexis Inc., Redwood City, CA, USA),

KRED-NADPH-121 (from Codexis Inc., Redwood City, CA, USA),

KRED-NADPH-123 (from Codexis Inc., Redwood City, CA, USA),

KRED-NADPH-145 (from Codexis Inc., Redwood City, CA, USA),

KRED-NADPH-155 (from Codexis Inc., Redwood City, CA, USA),

A231 (from Almac Group Ltd. Craigavon, United Kingdom) and

KRED-NADPH-136 (from Enzysource, Hangzhou, China).

Other suitable oxidoreductases catalyzing the asymmetric reduction of a compound of formula (V) to a compound of formula (III) are diastereoselective NADPH-dependent oxidoreductases selected from the list of:

KRED-X1, an engineered ketoreductase enzyme from Lactobacillus kefir (Lactobacillus kefir) as disclosed in PCT International publication No. WO2010/025238A2 and identified as SEQ. ID. NO.34, and

KRED-X2, an engineered ketoreductase enzyme from saccharomyces ochraceus (Sporobolomyces salmonicolor), as disclosed in PCT international publication No. WO2009/029554a2 and identified as seq.id No. 138.

Other suitable oxidoreductases that catalyze the asymmetric reduction of a compound of formula (V) to a compound of formula (III) are the commercially available variants of KRED-X1 (from Codexis Inc., Redwood City, CA, USA).

Particularly suitable is the engineered ketoreductase "KRED-X1-P1B 06", a KRED variant "P1B 06" from Codexis KRED SPECIALTY Board product "KRED-X1-SPECIATY-PLT".

Other suitable oxidoreductases that catalyze the asymmetric reduction of a compound of formula (V) to a compound of formula (III) are the commercially available variants of KRED-X1 (from Codexis Inc., Redwood City, CA, USA). Particularly suitable are the following engineered ketoreductases from the Codexis KRED SPECIALTY Board product "KRED-X1.1-B06-SPECIATY-PLT":

"KRED-X1.1-P1F 01" (KRED variant P1F01),

"KRED-X1.1-P1H 10" (KRED variant P1H10),

"KRED-X1.1-P1G 11" (KRED variant P1G11),

"KRED-X1.1-P1C 04" (KRED variant P1C04),

"KRED-X1.1-P1C 11" (KRED variant P1C11) and

"KRED-X1.1-P1C 08" (KRED variant P1C 08).

Particularly suitable are the engineered ketoreductases "KRED-X1.1-P1C 04" and "KRED-X1.1-P1F 01". The most specific ketoreductase is the engineered ketoreductase "KRED-X1.1-P1F 01".

PCT international publication numbers WO2010/025085a2 and WO2009/029554a2 are hereby incorporated by reference in their entirety for all purposes, particularly with respect to the preparation and use of oxidoreductases.

It is also possible to use the cofactor NADH for all the above-mentioned enzymes.

In a particular aspect of the invention, the oxidoreductase catalyzing the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is a diastereoselective NADPH-dependent oxidoreductase selected from the list of: KRED-NADPH-111, KRED-NADPH-112, KRED-NADPH-113, KRED-NADPH-114, KRED-NADPH-115, KRED-NADPH-121, KRED-NADPH-123, KRED-NADPH-145, KRED-NADPH-155, A231, KRED-NADPH-136, KRED-X1, KRED-X2, KRED-X1-P1B06, KRED-X1.1-P1F01, KRED-X1.1-P1H10, KRED-X1.1-P1G11, KRED-X1.1-P1C04, KRED-X1.1-P1C11, and KRED-X1.1-P1C 08.

In a particular aspect of the invention, the oxidoreductase catalyzing the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is a diastereoselective NADPH-dependent oxidoreductase selected from the list of: KRED-X1, KRED-X2, KRED-X1-P1B06, KRED-X1.1-P1F01, KRED-X1.1-P1H10, KRED-X1.1-P1G11, KRED-X1.1-P1C04, KRED-X1.1-P1C11 and KRED-X1.1-P1C 08.

In a particular aspect of the invention, the oxidoreductase catalyzing the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is a diastereoselective NADPH-dependent oxidoreductase selected from the list of: KRED-X1, KRED-X2, KRED-X1-P1B06, KRED-X1.1-P1C04 and KRED-X1.1-P1F 01.

In a particular aspect of the invention, the oxidoreductase catalyzing the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is a diastereoselective NADPH-dependent oxidoreductase selected from the list of: KRED-X1, KRED-X1-P1B06, KRED-X1.1-P1C04 and KRED-X1.1-P1F 01.

In a particular aspect of the invention, the oxidoreductase catalyzing the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is a diastereoselective NADPH-dependent oxidoreductase selected from the list of: KRED-X1 and KRED-X2.

In a particular aspect of the invention, the oxidoreductase catalyzing the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is a diastereoselective NADPH-dependent oxidoreductase selected from the list of: KRED-X1 and KRED-X1-P1B 06.

In a particular aspect of the invention, the oxidoreductase catalyzing the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is a diastereoselective NADPH-dependent oxidoreductase selected from the list of: KRED-X1.1-P1C04 and KRED-X1.1-P1F 01.

In a particular aspect of the invention, the oxidoreductase catalyzing the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is the diastereoselective NADPH-dependent oxidoreductase KRED-X1.1-P1F 01.

In one aspect of the invention, the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is carried out in an aqueous medium in the presence of one or more organic co-solvents.

In one aspect of the invention, the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is carried out in an aqueous medium in the presence of one or more organic co-solvents, wherein the organic co-solvents are present in a total concentration of 1 to 50V%, in particular 4 to 40V%.

In one aspect of the invention, the co-solvent present in the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is selected from the list of: glycerol, 2-propanol, diethyl ether, tert-butyl methyl ether, diisopropyl ether, dibutyl ether, methyl tetrahydrofuran, ethyl acetate, butyl acetate, toluene, heptane, hexane, cyclohexene, and mixtures thereof; in particular 2-propanol.

2-propanol is particularly useful as a co-solvent because it can act as the final reducing agent for substrate coupling cofactor regeneration.

In one aspect of the invention, the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is carried out at a reaction temperature between 1 ℃ and 50 ℃, in particular between 20 ℃ and 45 ℃.

Temperatures within the upper range increase the reaction rate and facilitate acetone removal.

In one aspect of the invention, the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is carried out at a pH between 5.5 and 8.5.

In one aspect of the invention, the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is carried out in an aqueous buffer solution. Suitable buffers are known to the expert in the field. Specific buffers are 2- (N-morpholino) ethanesulfonic acid (MES) or potassium dihydrogen Phosphate (PBS).

The optimum pH range, and therefore any suitable buffer, depends on the particular oxidoreductase enzyme employed.

One aspect of the present invention relates to the asymmetric reduction of a compound of formula (V) to a compound of formula (III), wherein the compound of formula (V) is initially present at a concentration of 1 to 25 wt.%, in particular 10 to 20 wt.%.

One aspect of the present invention relates to the asymmetric reduction of a compound of formula (V) to a compound of formula (III), wherein the reaction concentration (total concentration of ketone of formula (V) and chiral alcohol of formula (III) in the reaction mixture) is between 1 and 25 wt.%, in particular between 10 and 20 wt.%.

One aspect of the invention relates to a process for the manufacture of a compound of formula (III) comprising asymmetric reduction of a compound of formula (V) catalyzed by a redox enzyme, followed by treatment by extraction or by filtration.

One aspect of the present invention relates to the asymmetric reduction of a compound of formula (V) to a compound of formula (III) catalyzed by a redox enzyme, wherein the product is conventionally treated by extraction or by filtration.

The crude product purity may be further increased by crystallization or used as such in a subsequent reaction sequence to make the compound of formula (I).

One aspect of the present invention relates to a process for the manufacture of a compound of formula (III) comprising an asymmetric reduction of a compound of formula (V) catalyzed by a redox enzyme, followed by treatment by extraction or by filtration and further by crystallization.

One aspect of the present invention relates to the asymmetric reduction of a compound of formula (V) to a compound of formula (III), wherein the product is conventionally worked up by extraction or by filtration and further by crystallization.

One aspect of the present invention relates to methods for making compounds of formula (IVc):

or a salt thereof, wherein R¹And R³As defined herein, the method comprises reacting a compound of formula (IVd):

or a salt thereof with R¹-X, wherein X is a leaving group, under conditions sufficient to produce a compound of formula IVc or a salt thereof.

In one embodiment, the process comprises making ethyl (E) -3- (tert-butoxycarbonyl (isopropyl) -amino) -2- (4-chlorophenyl) acrylate or a salt thereof, wherein R is¹Is a BOC protecting group, R³Is ethyl, and wherein R¹-X is (BOC)₂O。

In a particular embodiment, the process comprises admixing a compound of formula IVd or a salt thereof with less than about 8 equivalents, particularly less than about 4 equivalents, more particularly about 3 equivalents of (BOC)₂O in a polar solvent mixture comprising DMF under conditions to produce a compound of formula IVc or a salt thereof in a yield of greater than about 50%, particularly about 75% or greater than 75% yield.

In a more particular embodiment, the conditions comprise contacting a compound of formula IVd or a salt thereof with about 3 equivalents (BOC) in a mixture of polar solvents comprising DMF₂O and a basic mixture comprising about 2 equivalents each of tributylamine and Dimethylaminopyridine (DMAP). In one embodiment, the method further comprises adding (BOC)₂During O a portion of the liquid was removed from the reaction mixture under vacuum.

The compounds of formula (V) may be prepared according to methods known to those skilled in the art. One particular general method for preparing the compounds of formula (V) is depicted in scheme 3. For a more detailed description of the individual reaction steps, see the examples section below.

Scheme 3

Reaction of a compound of formula (Va) with an iodinating agent (e.g. an iodide salt such as NaI, and optionally with an acid) produces a diiodopyrimidine of formula (Vb) which can be further reacted with a mono-protected piperazine to provide a compound of formula (Vc). With a metallating agent, such as a Grignard reagent (e.g. C)_1-7Alkylmagnesium halides, such as iPrMgCl) metalate the compound of formula (Vc) to form the compound of formula (Vd), which is further cyclized to form cyclopentanone of formula (V), wherein

R²As described herein, in the context of the present disclosure,

g is Li or Mg, and the content of the alloy is,

R⁶is a compound of the formula Cl or OH,

R⁷is-CN, -COOR^aor-CONR^aR^bWherein R is^aAnd R^bIndependently selected from hydrogen, -OH, C_1-7Alkoxy radical, C_1-7Alkyl radical, C_2-7Alkenyl radical, C_2-7Alkynyl, C_3-8List of cycloalkyl, phenyl or 3 to 12 membered heterocycloalkyl; or R^aAnd R^bTogether with the nitrogen atom to which they are attached form a 3-7 membered heterocycloalkyl group.

WO 2008/006040 discloses a process for the manufacture of a compound of formula (73), wherein a compound of formula (71) is acylated with an appropriate amino acid after deprotection with an acid, wherein R and R⁵Various alternatives are possible.

The acylation reaction as described in the prior art exhibits the following disadvantages:

the method using HBTU as the coupling reagent is not suitable for large-scale commercial manufacturing processes. HBTU poses serious industrial hygiene problems because cases of allergic and occupational allergic Contact Dermatitis are described in the literature (Hannu t. et al, occupancy Med,2006,56(6), 430-.

The process using dichloromethane as a solvent is not suitable for large-scale commercial manufacturing processes because dichloromethane is classified as a Hazardous Air Pollutant (HAP) in the united states. Furthermore, it is rated by the international harmonization conference (ICH) as a class 2 solvent with strict allowable daily exposure (PDE) due to the inherent toxicity of dichloromethane.

Due to the extremely high solvent consumption and low throughput of chromatography, purification of the product using chromatography is not an acceptable purification method for large scale small molecule manufacture.

In the case where more than one solvent is involved in a mixture in a commercial large scale reaction process, the solvents need different boiling points sufficient to achieve separation from each other to allow separation from each other and recycle using distillation. A process involving four solvents in the same step (e.g. in the case of cyclopentyl methyl ether (CPME)) which is not recyclable because the mixture is not separable is not suitable for large scale manufacture.

The treatment of the product requires numerous (e.g. six) aqueous extractions, all of which are accompanied by concentrated inorganic salts, thus generating large amounts of contaminated wastewater. Such process conditions result in a production process that is environmentally unfavorable.

The present inventors have found a novel and improved process for the manufacture of compounds of formula (I) which comprises coupling a compound of formula (II) as a salt, particularly a sodium salt, to a compound of formula (III). It has been found that the use of a compound of formula (II) in the form of a salt, particularly a sodium salt, substantially facilitates and simplifies such processes compared to the use of free amino acids.

The process according to the invention for the manufacture of the compound of formula (I) is characterized by a number of relevant advantages compared to the processes described in the art, such as in particular:

the treatment of the compounds of formula (I) is considerably improved. Only three solvents (isopropanol, toluene and heptane) were used which could be separated well.

Propylphosphonic anhydride (T3P) is a non-toxic coupling agent with no allergenic and sensitizing properties.

The by-products of the reaction are water soluble and can therefore be easily removed by, for example, triple aqueous extraction.

One aspect of the present invention provides a process for the preparation of a compound of formula (I)

Or a salt thereof, comprising a compound of formula (II)

With compounds of the formula (III)

In which R is¹、R²And M is as defined herein.

One aspect of the present invention provides a process for the preparation of a compound of formula (I) or a salt thereof, comprising a coupling reaction of a compound of formula (II) with a compound of formula (III), wherein R¹、R²And M is as defined herein, comprising the following reaction steps:

a) deprotecting the compound of formula (III) in a solvent under acidic conditions;

b) adjusting to alkaline pH using a base;

c) adding a solution comprising the compound of formula (II) in a solvent;

d) a solution comprising a coupling agent in a solvent is added.

In one aspect of the invention, the deprotection in step a) is carried out using hydrochloric acid, sulfuric acid, trifluoroacetic acid or hydrobromic acid.

In a particular aspect of the invention, the deprotection in step a) is carried out using hydrochloric acid.

In one aspect of the invention, the solvent used for the deprotection in step a) is selected from the group consisting of water, methanol, ethanol, n-propanol, isopropanol, n-butanol and tert-butanol.

In a particular aspect of the invention, the solvent used for the deprotection in step a) is selected from n-propanol or isopropanol.

In one aspect of the invention, the deprotection in step a) is carried out at a temperature of 50 to 100 ℃, in particular at 80 ℃.

In one aspect of the invention, the deprotection in step a) is carried out during a reaction time of 0.1 to 24 hours, in particular during a reaction time of 1 to 2 hours.

In one aspect of the invention, the base in step b) is a liquid base selected from the group consisting of N-ethylmorpholine (NEM), Triethylamine (TEA), tri (N-propyl) amine (TPA), Diisopropylethylamine (DIPEA), pyridine and lutidine.

In one aspect of the invention, the base in step b) is N-ethylmorpholine (NEM).

In one aspect of the invention, in step b), 4 to 8 equivalents of base, in particular 6 to 7 equivalents of base, most in particular 6.5 equivalents of base, are added with respect to the compound of formula (III).

In one aspect of the invention, the solvent used in step c) is the same as the solvent used in step a).

In one aspect of the invention, the solvent used in step c) is selected from the group consisting of water, methanol, ethanol, n-propanol, isopropanol, n-butanol and tert-butanol.

In a particular aspect of the invention, the solvent in step c) is selected from n-propanol or isopropanol.

In one aspect of the invention, the coupling agent used in step d) is propylphosphonic anhydride (T3P).

In one aspect of the invention, the solvent used in step d) is selected from the group consisting of methanol, ethanol, N-propanol, isopropanol, N-butanol, t-butanol, toluene, acetonitrile, tetrahydrofuran, N-dimethylformamide, chloroform, dichloromethane, dichloroethane, diethyl ether, acetone, methyl ethyl ketone, dimethyl sulfoxide, N-dimethylacetamide, N-methylpyrrolidone, dioxane, tetrahydropyran, pyridine, 2-acetone, 2-butanone, ethylene glycol dimethyl ether, ethyl acetate, butyl acetate, isopropyl acetate and mixtures thereof.

In a particular aspect of the invention, the solvent used in step d) is selected from a mixture of n-propanol and toluene or isopropanol and toluene, most particularly a mixture of n-propanol and toluene.

In one aspect of the invention, the coupling reaction in step d) is carried out at a temperature of-10 to 50 ℃, in particular 0 to 25 ℃.

In one aspect of the invention, the coupling reaction in step d) is carried out during a reaction time of 0.1 to 24 hours, in particular during a reaction time of 1 to 4 hours.

One aspect of the present invention relates to a coupling reaction of a compound of formula (II) with a compound of formula (III), wherein after step d) the product is worked up by aqueous extraction.

In a particular aspect of the invention, the treatment of the product after step d) comprises an extraction with water of from 1 to 6 times, in particular 3 times.

One aspect of the present invention relates to processes for the manufacture of compounds of formula (VI)

Or a pharmaceutically acceptable salt thereof, wherein a compound of formula (I)

Deprotection of R wherein¹As defined herein.

One aspect of the present invention relates to a process for the manufacture of a compound of formula (VI) or a pharmaceutically acceptable salt thereof, wherein a compound of formula (I) is deprotected, wherein R¹As defined herein, comprising the following reaction steps:

i) deprotecting the compound of formula (I) in a solvent under acidic conditions;

ii) adjusting the pH with a base used in a solvent;

iii) optionally crystallizing said compound of formula (VI).

In one aspect of the invention, the deprotection in step i) is carried out using hydrochloric acid, sulfuric acid, trifluoroacetic acid or hydrobromic acid.

In a particular aspect of the invention, the deprotection in step i) is carried out using hydrochloric acid.

In one aspect of the invention, the solvent used for deprotection in step i) is selected from water, methanol, ethanol, n-propanol, isopropanol and tert-butanol or mixtures thereof.

In a particular aspect of the invention, the solvent used for the deprotection in step i) is selected from n-propanol, isopropanol and a 1:1 mixture of n-propanol/water.

In one aspect of the invention, the deprotection in step i) is carried out at a temperature of 30 to 100 ℃, in particular at 80 ℃.

In one aspect of the invention, the deprotection in step i) is carried out during a reaction time of 1 to 24 hours, in particular during a reaction time of 1 to 4 hours.

In one aspect of the invention, the base in step ii) is NaOH in a 1:1 mixture of n-propanol/water.

In one aspect of the invention, the base in step ii) is ammonia.

In one aspect of the invention, the solvent used in step ii) is the same as the solvent used in step i).

In one aspect of the invention, the solvent used in step ii) is selected from water, methanol, ethanol, n-propanol, isopropanol, n-butanol and tert-butanol or mixtures thereof.

In a particular aspect of the invention, the solvent in step ii) is selected from n-propanol, isopropanol and a 1:1 mixture of n-propanol/water.

In a particular aspect of the invention, the pH adjustment is carried out by dropwise addition of a solution of ammonia in isopropanol (2-4% by weight, in particular 3.8% by weight) or NaOH in a 1:1 mixture of n-propanol/water (5-10M, in particular 7M).

In a particular aspect of the invention, the final pH after adjustment in step ii) is higher than pH6, in particular between pH6 and 7.

In one aspect of the invention, the crystallization in step iii) is carried out by converting the solvent into a crystallization solvent suitable for crystallizing the compound of formula (VI).

In a particular aspect of the invention, the crystallization solvent in step iii) is selected from the group consisting of toluene, heptane, tetrahydrofuran, 2-propanone, 2-butanone, ethylene glycol dimethyl ether, ethyl acetate, butyl acetate, isopropyl acetate and mixtures thereof.

In a particular aspect of the invention, the crystallization solvent in step iii) is ethyl acetate.

One aspect of the present invention relates to a compound obtainable by any of the methods as described herein.

One aspect of the present invention relates to a pharmaceutical composition comprising a compound obtainable by any of the methods as described herein.

One aspect of the present invention relates to a compound of formula (VI) as described herein, comprising between 1ppb and 100ppm of a compound of formula (I), wherein R¹As defined herein.

One aspect of the present invention relates to a compound of formula (VI) as described herein, comprising between 1ppb and 1ppm of a compound of formula (I), wherein R¹As defined herein.

One aspect of the present invention relates to a pharmaceutical composition comprising a compound of formula (VI) as described herein.

One aspect of the present invention relates to a compound of formula (I) as described herein, comprising between 1ppb and 100ppm of a compound of formula (II), wherein R¹And M is as defined herein.

One aspect of the present invention relates to a compound of formula (I) as described herein comprising between 1ppb and 1ppm of a compound of formula (II), wherein R¹And M is as defined herein.

One aspect of the present invention relates to a compound of formula (I) as described herein, comprising between 1ppb and 100ppm of a compound of formula (III), wherein R¹And R²As defined herein.

One aspect of the present invention relates to a compound of formula (I) as described herein comprising between 1ppb and 1ppm of a compound of formula (III), wherein R¹And R²As defined herein.

One aspect of the present invention relates to a compound of formula (I) as described herein, comprising between 1ppb and 100ppmAnd between 1ppb and 100ppm of a compound of formula (III), wherein R¹、R²And M is as defined herein.

One aspect of the present invention relates to a compound of formula (I) as described herein comprising between 1ppb and 1ppm of a compound of formula (II) and between 1ppb and 1ppm of a compound of formula (III), wherein R¹、R²And M is as defined herein.

The invention also relates to the following:

1. a process for the preparation of a compound of formula (I)

Or a salt thereof, comprising a compound of formula (II)

With compounds of the formula (III)

In a coupling reaction of (b), wherein

R¹Is an amino protecting group selected from the list of benzyl, benzyloxycarbonyl (benzyloxycarbonyl, CBZ), 9-fluorenylmethyloxycarbonyl (Fmoc), p-methoxybenzyloxycarbonyl, p-nitrobenzyloxycarbonyl, tert-Butoxycarbonyl (BOC) and trifluoroacetyl.

R²Is an amino protecting group selected from the list of benzyl, benzyloxycarbonyl (benzyloxycarbonyl, CBZ), 9-fluorenylmethyloxycarbonyl (Fmoc), p-methoxybenzyloxycarbonyl, p-nitrobenzyloxycarbonyl, tert-Butoxycarbonyl (BOC) and trifluoroacetyl.

M is a metal ion selected from the list of alkali metal ions, alkaline earth metal ions and transition metal ions.

2. The method according to item 1Wherein R is¹Is tert-Butoxycarbonyl (BOC).

3. The method of any one of items 1 or 2, wherein R²Is tert-Butoxycarbonyl (BOC).

4. The method according to any one of items 1 to 3, wherein M is an alkali metal ion.

5. The method according to any one of items 1 to 4, wherein M is Na⁺。

6. The process according to any one of items 1 to 5, comprising the following reaction steps:

a) deprotecting the compound of formula (III) in a solvent under acidic conditions;

b) adjusting to alkaline pH using a base;

c) adding a solution comprising the compound of formula (II) in a solvent;

d) a solution comprising a coupling agent in a solvent is added.

7. The process according to any one of items 1 to 6, wherein the deprotection in step a) is carried out using hydrochloric acid.

8. The process according to any one of items 1 to 7, wherein the solvent used for deprotection in step a) is selected from n-propanol or isopropanol.

9. The process according to any one of items 1 to 8, wherein the base in step b) is selected from N-ethylmorpholine (NEM), Triethylamine (TEA), tri (N-propyl) amine (TPA), Diisopropylethylamine (DIPEA), pyridine and lutidine.

10. The process according to any one of items 1 to 9, wherein the base in step b) is N-ethylmorpholine (NEM).

11. The process according to any one of items 1 to 10, wherein the solvent in step c) is selected from n-propanol or isopropanol.

12. The process according to any one of items 1 to 11, wherein the coupling agent used in step d) is propylphosphonic anhydride (T3P).

13. The process according to any one of items 1 to 12, wherein the solvent used in step d) is a mixture of n-propanol and toluene.

14. The process of any one of items 1 to 13, wherein after step d), the product is treated by aqueous extraction.

15. The method of any one of items 1 to 14, further comprising a process for making a compound of formula (II)

Which comprises reacting a compound of the formula (IV) with a metal complex catalyst (C)

Asymmetric hydrogenation, wherein R¹And M is as defined in any one of items 1 to 5.

16. A process for the manufacture of a compound of formula (II)

Which comprises reacting a compound of the formula (IV) with a metal complex catalyst (C)

Asymmetric hydrogenation, wherein R¹And M is as defined in any one of items 1 to 5.

17. The process according to item 15 or 16, wherein the metal complex catalyst (C) is a ruthenium complex catalyst selected from compounds of formula (C1), (C2) or (C3):

Ru(Z)₂D (C1)

[Ru(Z)_2-p(D)(L)_m](Y)_p (C2)

Ru(E)(E’)(D)(F) (C3)

wherein:

d is a chiral phosphine ligand;

l is a neutral ligand selected from：C_2-7Alkene, cyclooctene, 1, 3-hexadiene, norbornadiene, 1, 5-cyclooctadiene, benzene, hexamethylbenzene, 1,3, 5-trimethylbenzene, p-cymene, tetrahydrofuran, dimethylformamide, acetonitrile, benzonitrile, acetone, toluene, and methanol;

z is an anionic ligand selected from: hydride, fluoride, chloride, bromide,. eta⁵-2, 4-pentadienyl eta⁵-2, 4-dimethyl-pentadienyl or a radical A-COO^-Provided that when two Z's are attached to the Ru atom, they may be the same or different;

a is C_1-7Alkyl radical, C_1-7Haloalkyl, aryl or haloaryl;

y is a non-coordinating anion selected from: fluoride ion, chloride ion, bromide ion, BF₄ ^-、ClO₄ ^-、SbF₆ ^-、PF₆ ^-B (phenyl)₄ ^-B (3, 5-bis-trifluoromethyl-phenyl)₄ ^-、CF₃SO₃ ^-And C₆H₅SO₃ ^-；

F is an optionally chiral diamine;

e and E 'are both halide ions, or E is a hydride ion and E' is BH₄ ^-；

m is 1,2, 3 or 4; and is

p is 1 or 2.

18. The process of any one of claims 15 to 17, wherein the ruthenium complex catalyst is Ru (Z)₂D, wherein Z and D are as defined in item 17.

19. The method of any one of claims 15 to 18, wherein the anionic ligand (Z) is independently selected from chloride, bromide, iodide, OAc, and TFA.

20. The method of any one of claims 15 to 19, wherein the anionic ligand (Z) is Trifluoroacetate (TFA).

21. The method according to any one of claims 15 to 17, wherein the neutral ligands (L) are independently selected from benzene (C)₆H₆) p-PCym) and Acetonitrile (AN).

22. The method according to any one of claims 15 to 17, wherein the neutral ligand (L) is benzene (C)₆H₆)。

23. The method of any one of items 15 to 17, wherein the non-coordinating anion (Y) is selected from chloride, bromide, iodide, and BF₄ ^-。

24. The method of any one of items 15 to 17, wherein the non-coordinating anion (Y) is BF₄ ^-。

25. The method of any one of claims 15 to 17, wherein m is 1 or 4.

26. The method of any one of claims 15 to 17, wherein E and E' are both chloride.

27. The process of any one of items 15 to 17, wherein the chiral diamine F is (1S,2S) -1, 2-diphenylethylenediamine (S, S-DPEN).

28. The process of any one of items 15 to 17, wherein the chiral phosphine ligand D is selected from compounds of formulae (D1) to (D12):

wherein:

R¹¹is C_1-7Alkyl radical, C_1-7Alkoxy, hydroxy or C_1-7alkyl-C (O) O-;

R¹²and R¹³Each independently is hydrogen, C_1-7Alkyl radical, C_1-7Alkoxy or di (C)_1-7Alkyl) amino; or

R bound to the same phenyl group¹¹And R¹²Or R attached to the same phenyl group¹²And R¹³Together are-X- (CH)₂)_r-Y-, wherein X is-O-or-C (O) O-, Y is-O-, -N (lower alkyl) -or-CF₂-, and r is an integer of 1 to 6; or

Two R¹¹Together are-O- (CH)₂)_s-O-or O-CH (CH)₃)-(CH₂)_s-CH(CH₃) -O-, wherein s is an integer from 1 to 6; or

R¹¹And R¹²Or R¹²And R¹³Together with the carbon atom to which they are attached form a naphthyl, tetrahydronaphthyl or dibenzofuran ring;

R¹⁴and R¹⁵Each independently is C_1-7Alkyl radical, C_3-8Cycloalkyl, phenyl, naphthyl, or heteroaryl, optionally substituted with 1 to 7 substituents independently selected from the group consisting of: c_1-7Alkyl radical, C_1-7Alkoxy, di (C)_1-7Alkyl) amino, morpholinyl, phenyl, tri (C)_1-7Alkyl) silyl, C_1-7Alkoxycarbonyl, hydroxycarbonyl, hydroxysulfonyl, (CH)₂)_t-OH and (CH)₂)_t-NH₂Wherein t is an integer from 1 to 6;

R¹⁶is C_1-7An alkyl group;

R¹⁷is C_1-7An alkyl group; and is

R¹⁸Independently is aryl, heteroaryl, C_3-8Cycloalkyl or C_1-7An alkyl group.

29. The process according to any one of items 15 to 17, wherein the chiral phosphine ligand (D) is selected from the compounds of formula (D1), wherein R is¹¹To R¹⁵As described in item 28.

30. The method according to any one of items 15 to 17 and 28 to 29, wherein the chiral phosphine ligand (D) is selected from (R) -3,5-Xyl-BINAP, (R) -BINAP, (S) -2-furyl-MeOBIPHEP, (S) -BINAP, (S) -BIPHEMP, (S) -MeOBIPHEP, (S) -pTol-BINAP), (S) -TMBTP and (S, S) -iPr-DUPHOS.

31. The process according to any one of items 15 to 17 and 28 to 30, wherein the chiral phosphine ligand (D) is selected from (S) -BIPHEMP, (S) -BINAP and (S) -MeOBIPHEP.

32. The process according to any one of items 15 to 17 and 28 to 31, wherein the chiral phosphine ligand (D) is (S) -BINAP.

33. The method of any one of items 15 to 17, wherein the ruthenium complex catalyst is selected from the group of:

Ru(TFA)₂((R)-3,5-Xyl-BINAP)、

Ru(OAc)₂((S) -2-furyl-MeOBIPHEP),

Ru(OAc)₂((S)-BINAP)、

[Ru(OAc)₂((S)-BINAP)]AlCl₃、

Ru(TFA)₂((S)-BINAP)、

Ru(TFA)₂((S)-BINAPHANE)、

Ru(TFA)₂((S)-BIPHEMP)、

Ru(OAc)₂((S)-MeOBIPHEP)、

Ru(TFA)₂((S)-TMBTP)、

Ru(TFA)₂((S,S)-iPr-DUPHOS)、

[Ru((R)-BINAP)(pCym)(AN)](BF₄)₂、

[RuBr((S)-BINAP)(C₆H₆)]Br、

[RuCl((S)-BINAP)(C₆H₆)]BF₄、

[RuI((S)-BINAP)(C₆H₆)]I、

[Ru((S)-BINAP)(AN))₄](BF₄)₂And

RuCl₂((S)-pTol-BINAP)(S,S-DPEN)。

34. the method of any one of claims 15 to 17, wherein the ruthenium complex catalyst is ru (tfa)₂((S)-BINAP)。

35. The process according to any one of items 15 to 34, wherein the asymmetric hydrogenation of compound of formula (IV) is carried out in a solvent selected from alcohols, hydrocarbons, chlorinated hydrocarbons, fluorinated and polyfluorinated aliphatic or aromatic hydrocarbons, supercritical or liquid carbon dioxide, THF, water or mixtures thereof.

36. The process of any one of items 15 to 35, wherein the asymmetric hydrogenation of compound of formula (IV) is carried out in a solvent selected from the list of: MeOH, EtOH, i-PrOH, EtOH/cyclopentylmethyl ether, EtOH/CH₂Cl₂、EtOH/EtOAc、EtOH/THF、EtOH/H₂O、CH₂Cl₂And THF.

37. The process of any one of items 15 to 36, wherein the asymmetric hydrogenation of compound of formula (IV) is carried out in ethanol (EtOH).

38. The process of any one of items 15 to 37, wherein the asymmetric hydrogenation of compound of formula (IV) further comprises one or more compounds selected from LiBF₄、LiPF₆、LiO₃SCF₃、NaCl、NaBr、NaI、KCl、KBr、KI、LiCl、LiBr、LiI、HBF₄、HCl、HBr、H₂SO₄And CH₃SO₃H list of additives.

39. The process according to any one of items 15 to 38, wherein the asymmetric hydrogenation of compound of formula (IV) is carried out under a hydrogen pressure of 1 to 150 bar.

40. The process according to any one of items 15 to 39, wherein the asymmetric hydrogenation of compound of formula (IV) is carried out under a hydrogen pressure of 10 to 30 bar.

41. The process of any one of items 15 to 40, wherein the asymmetric hydrogenation of compound of formula (IV) is carried out at a substrate/catalyst ratio (S/C) of 5 to 100' 000.

42. The process of any one of items 15 to 41, wherein the asymmetric hydrogenation of compound of formula (IV) is carried out at a substrate/catalyst ratio (S/C) of from 100 to 15' 000.

43. The process of any one of items 15 to 42, followed by adding formula C to the hydrogenation reaction mixture_1-7Alcohol solutions of alkyl-OM metal alkoxides to form salts, wherein R¹And M is as defined in items 1 to 4.

44. The method of any item 43, wherein the metal alkoxide employed in the salt forming step is MeOM, EtOM, iPrOM, nPROM, nBuOM, iBuOM, or tBuOM.

45. The method of any one of clauses 43 or 44, wherein the metal alkoxide employed in the salt forming step is EtOM.

46. The method of any one of items 43 to 45, wherein the alcohol used as the solvent in the salt formation step is C_1-7alkyl-OH, more particularly MeOH, EtOH, iPrOH, nPrOH, nBuOH, iBuOH or tBuOH.

47. The method of any one of items 43 to 46, wherein the alcohol used as the solvent in the salt formation step is EtOH.

48. The method of any one of items 1 to 14, further comprising a process for making a compound of formula (III)

Which comprises reacting a compound of formula (V) catalyzed by a redox enzyme

Asymmetric reduction, wherein R²As defined in any one of items 1 and 3.

49. A process for the manufacture of a compound of formula (III)

Which comprises reacting a compound of formula (V) catalyzed by a redox enzyme

Asymmetric reduction, wherein R²As defined in any one of items 1 and 3.

50. The method of any one of items 48 or 49, wherein the oxidoreductase catalyzes the asymmetric reduction of the compound of formula (V) to the compound of formula (III) with diastereoselectivity of at least 95% diastereomeric excess (de).

51. The method of any one of items 48 to 50, wherein the oxidoreductase catalyzes the asymmetric reduction of the compound of formula (V) to the compound of formula (III) with diastereoselectivity to at least 98% de.

52. The method of any one of items 48 to 51, wherein the asymmetric reduction of a compound of formula (V) to a compound of formula (III) is catalyzed by an oxidoreductase in the presence of a cofactor.

53. The method of any item 52, wherein the cofactor that is oxidized in the asymmetric reduction of compound of formula (V) to compound of formula (III) is NADH or NADPH.

54. The method of any one of items 52 to 53, wherein the cofactor is regenerated in situ by enzyme-coupled cofactor regeneration using glucose and glucose dehydrogenase as cosubstrates.

55. The method of any one of items 52 to 53, wherein the cofactor is regenerated in situ by substrate coupling cofactor regeneration using a secondary alcohol as co-substrate.

56. The method of item 55, wherein the secondary alcohol used as co-substrate for substrate coupling regeneration is selected from 2-propanol, 2-butanol, butane-1.4-diol, 2-pentanol, pentane-1, 5-diol, 4-methyl-2-pentanol, 2-hexanol, hexane-1, 5-diol, 2-heptanol, or 2-octanol.

57. The method of any one of items 55 to 56, wherein the secondary alcohol used as co-substrate for regeneration of the substrate coupling cofactor is 2-propanol.

58. The method of any one of items 48 to 57, wherein the oxidoreductase is a diastereoselective NADPH-dependent oxidoreductase selected from the list of: KRED-NADPH-111, KRED-NADPH-112, KRED-NADPH-113, KRED-NADPH-114, KRED-NADPH-115, KRED-NADPH-121, KRED-NADPH-123, KRED-NADPH-145, KRED-NADPH-155, A231, KRED-NADPH-136, KRED-X1, KRED-X2, KRED-X1-P1B06, KRED-X1.1-P1F01, KRED-X1.1-P1H10, KRED-X1.1-P1G11, KRED-X1.1-P1C04, KRED-X1.1-P1C11, and KRED-X1.1-P1C 08.

59. The method of any one of items 48 to 58, wherein the oxidoreductase is a diastereoselective NADPH-dependent oxidoreductase selected from the list of: KRED-X1, KRED-X2, KRED-X1-P1B06, KRED-X1.1-P1F01, KRED-X1.1-P1H10, KRED-X1.1-P1G11, KRED-X1.1-P1C04, KRED-X1.1-P1C11 and KRED-X1.1-P1C 08.

60. The method of any one of items 48 to 59, wherein the oxidoreductase is a diastereoselective NADPH-dependent oxidoreductase selected from the list of: KRED-X1, KRED-X2, KRED-X1-P1B06, KRED-X1.1-P1C04 and KRED-X1.1-P1F 01.

61. The method of any one of items 48 to 60, wherein the oxidoreductase is a diastereoselective NADPH-dependent oxidoreductase selected from the list of: KRED-X1.1-P1C04 and KRED-X1.1-P1F 01.

62. The process of any one of items 48 to 61, wherein the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is carried out in an aqueous medium in the presence of one or more organic co-solvents.

63. The method of clause 62, wherein the organic co-solvent is present at a total concentration of 1 to 50V%.

64. The method of clause 62, wherein the organic co-solvent is present at a total concentration of 5 to 30V%.

65. The method of any one of items 48 to 64, wherein the organic co-solvent is selected from the list of: glycerol, 2-propanol, diethyl ether, tert-butyl methyl ether, diisopropyl ether, dibutyl ether, methyl tetrahydrofuran, ethyl acetate, butyl acetate, toluene, heptane, hexane, cyclohexene and mixtures thereof.

66. The method of any one of items 48 to 65, wherein the organic co-solvent is 2-propanol.

67. The process of any one of items 48 to 61, wherein the asymmetric reduction of the compound of formula (V) to the compound of formula (III) is carried out in an aqueous buffer solution.

68. The method of any claim 67, wherein the buffer is 2- (N-morpholino) ethanesulfonic acid (MES) or potassium dihydrogen Phosphate (PBS).

69. The method of any one of items 50 to 68, followed by treatment by extraction or by filtration.

70. The method of any one of items 1 to 14, further comprising for the manufacture of a compound of formula (VI)

Or a pharmaceutically acceptable salt thereof, wherein a compound of formula (I)

Deprotection of R wherein¹As defined in any one of items 1 to 2.

71. The method of clause 70, which comprises the reaction steps of:

i) deprotecting the compound of formula (I) in a solvent under acidic conditions;

ii) adjusting the pH with a base used in a solvent;

iii) optionally crystallizing said compound of formula (VI).

72. The process of any one of items 70 or 71, wherein the deprotection in step i) is carried out using hydrochloric acid, sulfuric acid, trifluoroacetic acid, or hydrobromic acid.

73. The method of any one of items 70 to 72, wherein the deprotection in step i) is performed using hydrochloric acid.

74. The method of any one of items 70 to 73, wherein the solvent used for deprotection in step i) is selected from n-propanol, isopropanol, and a 1:1 mixture of n-propanol/water.

75. The method of any one of items 70 to 74, wherein the base in step ii) is NaOH or ammonia.

76. The process of any one of items 70 to 75, wherein the solvent in step ii) is selected from n-propanol, isopropanol, and a 1:1 mixture of n-propanol/water.

77. The process of any one of items 70 to 76, wherein the crystallization in step iii) is carried out by converting the solvent to a crystallization solvent suitable for crystallizing the compound of formula (VI).

78. The process of item 77, wherein the crystallization solvent in step iii) is selected from the group consisting of toluene, heptane, tetrahydrofuran, 2-propanone, 2-butanone, ethylene glycol dimethyl ether, ethyl acetate, butyl acetate, isopropyl acetate, and mixtures thereof.

79. The process of clause 77, wherein the crystallization solvent in step iii) is ethyl acetate.

80. A variety of compounds obtainable by the method according to any one of items 1 to 79.

81. Various pharmaceutical compositions comprising a compound obtainable by a method according to any one of items 1 to 79.

82. A compound of formula (II)

Wherein R is¹And M is as defined in any one of items 1 to 5.

83. A compound of formula (II) according to item 82 which is sodium (S) -3- (tert-butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) propionate.

84. The compound of formula (VI) according to item 70 comprising between 1ppb and 100ppm of the compound of formula (I), wherein R¹As defined in any one of items 1 or 2.

85. The compound of formula (VI) according to item 70 comprising between 1ppb and 1ppm of the compound of formula (I), wherein R¹As defined in any one of items 1 or 2.

86. A pharmaceutical composition comprising a compound of formula (VI) according to any one of items 84 or 85.

87. A compound of formula (I) according to item 1 comprising between 1ppb and 100ppm of the compound of formula (II), wherein R¹And M is as defined in any one of items 1 to 5.

88. A compound of formula (I) according to item 1 comprising between 1ppb and 1ppm of the compound of formula (II), wherein R¹And M is as defined in any one of items 1 to 5.

89. A compound of formula (I) according to item 1 comprising between 1ppb and 100ppm of said formula(III) Compounds wherein R¹And R²As defined in any one of items 1 to 3.

90. A compound of formula (I) according to item 1 comprising between 1ppb and 1ppm of the compound of formula (III), wherein R¹And R²As defined in any one of items 1 to 3.

91. A compound of formula (I) according to item 1 comprising between 1ppb and 100ppm of the compound of formula (II) and between 1ppb and 100ppm of the compound of formula (III), wherein R¹、R²And M is as defined in any one of items 1 to 5.

92. A compound of formula (I) according to item 1 comprising between 1ppb and 1ppm of the compound of formula (II) and between 1ppb and 1ppm of the compound of formula (III), wherein R¹、R²And M is as defined in any one of items 1 to 5.

93. The invention as herein before described.

Examples

The following examples 1-15 are provided to illustrate the invention. They should not be considered as limiting the scope of the invention, but merely as being representative thereof.

Example 1

(E) -3- (tert-Butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) acrylic acid

To a solution of ethyl formate (123.9L, 1538.9mol) in MTBE (189L) was added 4-chlorophenylethyl acetate (120kg, 604.1 mol). The mixture was stirred at 15-30 ℃ for 30 minutes, followed by the addition of a mixture of t-BuOK (136.8kg, 1219.1mol) in MTBE (1215.8L) while maintaining the internal temperature below 5 ℃. The mixture was stirred at 0-10 ℃ for 1.5 hours. The reaction mixture was added to an aqueous solution of hydrochloric acid (35%, 99.8L at 560L H) while maintaining the internal temperature below 10 ℃₂0) in (c). The mixture was stirred between 0-10 ℃ for 30 minutes until a final pH of 2 was observed. The layers were separated and the organic layer was washed with 25% NaCl solution (496L).

Cooling the mixture to-5 deg.C, followed by maintaining the temperature<Isopropylamine (107.2L, 1251.9mol) and AcOH (70.5L, 1233.3mol) were added slowly at 10 ℃. The mixture was stirred at 0-10 ℃ for 3 hours, then successively with H₂O(760L)、15％Na₂C0₃The organic layer was washed with aqueous solution (424L) and 25% aqueous NaCl solution (650L). The aqueous layer was separated and DMF (443L) and DMAP (14.4kg, 117.9mol) were added to the organic solution. The mixture was then heated to 60-65 ℃ and then slowly added over 24 hours (Boc)₂O (951.6L, 4142mol), DMF (228.6L) and triethylamine (263.0L, 1821.8 mol). After stirring for about 6 hours, the mixture was cooled to room temperature and MTBE (1434L), water (1010L) and 10% aqueous citric acid solution (938L) were added. The aqueous layer was separated and the mixture was washed with 25% aqueous NaCl (984L). The organic layer was then concentrated by distillation to a minimum working volume (about 240L) while maintaining the temperature below 50 ℃. The organic layer was then stirred at 0-5 ℃ for 5 hours and filtered. The filter cake was washed with heptane (20.6L) and dried to provide ethyl (E) -3- ((tert-butoxycarbonyl) (isopropyl) amino) -2- (4-chlorophenyl) acrylate as a white solid (148.55kg, 63% yield over three steps).

Ethyl (E) -3- ((tert-butoxycarbonyl) (isopropyl) amino) -2- (4-chlorophenyl) acrylate (133.5kg, 362.9mol) was added to H stirred at room temperature₂O (252L), NaOH (58.25kg, 1456mol) and EtOH (383.5L). The mixture was warmed to 40-45 ℃ for 2.5 hours until a clear solution formed. The mixture was concentrated to the minimum working volume while maintaining the temperature below 50 ℃. The mixture was then cooled to 10-25 ℃ and a solution of HCl (842L 2N HCl and 11L 35% HCl) was added until a final pH of 2-4 was obtained. The aqueous layer was separated and the organic layer was washed with 25% aqueous NaCl solution (810L). N-heptane was added during distillation to form a suspension. The product was collected and washed with n-heptane, and dried at 40-45 ℃ for about 10 hours to provide 110.7kg (90.5% yield) of (E) -3- (tert-butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) acrylic acid having a purity of 99.9% by HPLC. Single crystal x-ray analysis was used to confirm the E configuration.

Example 1a

(E) -3- ((tert-butoxycarbonyl) - (isopropyl) amino) -2- (4-chlorophenyl) acrylic acid ethyl ester

To a concentrated solution of ethyl 2- (4-chlorophenyl) -3- (isopropylamino) acrylate (prepared as above in example 1 from 120kg of ethyl 2- (4-chlorophenyl) acetate, 0.604kmol) was added DMF (354kg) and the batch was concentrated to 3 volumes. DMAP (14.0kg, 114.6mol) and n-Bu were added₃N (224.21kg, 1.21kmol) and heating the mixture to 70-75 ℃ and adding (BOC) at 70-75 ℃ over 2 hours₂A solution of O (330kg, 1.51kmol) in DMF (169kg) solution. After the addition was complete, about 200L of DMF was removed under vacuum at less than 75 ℃ over 3 hours. Continuously adding water (BOC) at 70-75 deg.C within 0.5 hr₂O (68.6kg, 0.314kmol) in DMF (32.4 kg). After the addition was complete, the batch was concentrated at a temperature below 75 ℃ and then cooled to about 23.5 ℃. MTBE (899.6kg) was charged and the mixture was cooled to about 12.6 ℃. A solution of citric acid monohydrate (197.4kg) in water (702kg) was added at 10-20 ℃. The layers were separated and the organic layer was washed with 5% aqueous NaCl (582 kg). The layers were separated and the organic layer was concentrated to 240-360L at less than 50 ℃. After charging n-heptane (77kg), the mixture was concentrated to 240-360L at below 50 ℃. After charging with n-heptane (70kg), the suspension was stirred at 0-10 ℃ for 4 hours, and the product was collected by centrifugation. The cake was washed with n-heptane (28.2kg) and ethyl (E) -3- ((tert-butoxycarbonyl) (isopropyl) amino) -2- (4-chlorophenyl) acrylate (170.6kg, 77% yield, 99.8A% HPLC) was obtained, which was used as above in this example 1 to prepare (E) -3- (tert-butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) acrylic acid.

Example 2

(S) -3- (tert-Butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) propanoic acid sodium salt

In a glove box (O)₂Content 2ppm) was added to a 50ml autoclave, which was charged with 6.8g (20.0mmol) of (E) -2- (4-chlorophenyl) -3- [ (2-methylpropan-2-yl) oxycarbonyl-propan-2-ylamino]Prop-2-enoic acid, 34ml ethanol and 4.81mg (0.0051mmol, S/C4' 000) [ Ru (TFA)₂((S)-BINAP]. The asymmetric hydrogenation was carried out at 60 ℃ under 18 bar of hydrogen for 7 hours. After cooling to room temperature, the pressure was released from the autoclave and a sample of the yellow reaction solution was analyzed to show>99% conversion to (S) -3- (tert-butoxycarbonyl-isopropyl-amino) -2- (4-chloro-phenyl) -propionic acid, where the S/R enantiomeric ratio was 99.3 to 0.7. The hydrogenation mixture, which contains the crude reaction mixture of 6 analogous hydrogenation experiments (a total of 47.9g (E) -2- (4-chlorophenyl) -3- [ (2-methylpropan-2-yl) oxycarbonyl-propan-2-ylamino) was transferred under argon with the aid of 100ml of tert-butyl methyl ether into an 11-glass reactor]Prop-2-enoic acid), followed by dropwise addition of an ethanol solution of sodium ethoxide (52.3ml, 140mmol) at 50 ℃ under stirring. A pale yellow precipitate formed, which was stirred at the same temperature, followed by stirring at room temperature overnight. The precipitated product was filtered off, washed with tert-butyl methyl ether/ethanol 4:1 mixture (300ml) and tert-butyl methyl ether (200ml), dried under vacuum until the weight was constant to give a 96.3% yield and also an S/R enantiomeric ratio>99.9 ratio < 0.1% gave sodium (S) -3- (tert-butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) propionate (49.03g) as white crystals.¹H-NMR(D₂O). delta.7.32 (d,2H),7.22(d,2H),3.65-3.85 two broad singlet, aryl-CHAnd N-CH(CH₃)₂),3.55(m,2H),1.29(s,9H),1.00(d,3H),0.80(bs,3H)。

The enantiomeric ratio was determined by HPLC using a Chiralpak-AD-3 column of 150mm by 4.6 mm. Eluent: A) n-heptane with 0.10% trifluoroacetic acid, B) ethanol, flow rate: 1.25ml/min, 25 ℃,5 μ l injection volume, 220 nm. Retention time: (S) -3- (tert-butoxycarbonyl-isopropyl-amino) -2- (4-chloro-phenyl) -propionic acid 2.48 min, (R) -3- (tert-butoxycarbonyl-isopropyl-amino) -2- (4-chloro-phenyl) -propionic acid 2.77 min, (E) -2- (4-chlorophenyl) -3- [ (2-methylprop-2-yl) oxycarbonyl-prop-2-ylamino ] prop-2-enoic acid 3.16 min.

Example 3

(S) -3- (tert-Butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) propanoic acid sodium salt

In a glove box (O)₂Content 2ppm) to a 185ml autoclave were charged with 17.0g (50.0mmol) of (E) -2- (4-chlorophenyl) -3- [ (2-methylpropan-2-yl) oxycarbonyl-propan-2-ylamino]Prop-2-enoic acid, 70ml ethanol and 4.74mg (0.005mmol, S/C10' 000) [ Ru (TFA)₂((S)-BINAP]. The asymmetric hydrogenation was carried out at 70 ℃ under 18 bar of hydrogen for 22 hours. After cooling to room temperature, the pressure was released from the autoclave and a sample of the yellow reaction solution was analyzed to show>99% conversion to (S) -3- (tert-butoxycarbonyl-isopropyl-amino) -2- (4-chloro-phenyl) -propionic acid, where the S/R enantiomeric ratio was 98.2 to 1.8. The hydrogenation mixture was transferred under argon with the aid of 200ml of tert-butyl methyl ether into a 400ml glass reactor, followed by dropwise addition of an ethanol solution of sodium ethoxide (18.7ml, 50mmol) at 50 ℃ with stirring. A pale yellow precipitate formed, which was stirred at the same temperature, followed by stirring at room temperature for a total of 3.5 hours. The precipitated product was filtered off, washed with tert-butyl methyl ether/ethanol 4:1 mixture (80ml) and tert-butyl methyl ether (20ml), dried under vacuum until the weight was constant to yield sodium (S) -3- (tert-butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) propionate (17.35g) as white crystals in 94.6% yield and with S/R enantiomeric ratio 100 to 0%.

Example 3a

(S) -3- (tert-Butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) propanoic acid sodium salt

In a glove box (O)₂Content 2ppm) was added to a 185ml autoclave, which was charged with 10.0g (29.4mmol) of (E) -2- (4-chlorophenyl) -3- [ (2-methylpropan-2-yl) oxycarbonyl-propan-2-ylamino]Prop-2-enoic acid, 125mL ethanol, 0.118mL NaBr in water (1M) and 5.77mg (0.006mmol, S/C5' 000) [ Ru (TFA)₂((S)-BINAP]. The asymmetric hydrogenation was carried out at 60 ℃ under 18 bar of hydrogen for 22 hours. After cooling to room temperature, the pressure was released from the autoclave and a sample of the yellow reaction solution was analyzed to show>99% conversion to (S) -3- (tert-butoxycarbonyl-isopropyl-amino) -2- (4-chloro-phenyl) -propionic acid, where the S/R enantiomeric ratio was 98 to 2. By means of10mL of ethanol transferred the hydrogenation mixture to a 0.5L reactor. The reaction mixture was evaporated in vacuo at 45 ℃ to give a residual volume of 65 mL.

70ml of tert-butyl methyl ether were added at 45 ℃. A solution of sodium ethoxide (11.4g, 35mmol) in ethanol was then added dropwise with stirring at 45 ℃. The funnel was rinsed with 1.3g of ethanol. A pale yellow precipitate formed, which was stirred at the same temperature for 1 hour, followed by stirring at room temperature for 1 hour. The precipitated product was filtered off, washed with tert-butyl methyl ether/ethanol 1:1 mixture (13.6g) and tert-butyl methyl ether (16g), dried under vacuum until the weight was constant to yield sodium (S) -3- (tert-butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) propionate (9.52g) as white crystals in 89% yield and with S/R enantiomeric ratio 100 to 0%.

Example 3b

(S) -3- (tert-Butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) propanoic acid sodium salt

In a glove box (O)₂Content 2ppm) was added to a 185ml autoclave, which was charged with 10.0g (29.4mmol) of (E) -2- (4-chlorophenyl) -3- [ (2-methylpropan-2-yl) oxycarbonyl-propan-2-ylamino]Prop-2-enoic acid, 120mL ethanol (distilled under Ar), 0.118mL aqueous NaCl (1M) and 5.8mg (0.006mmol, S/C5' 000) [ Ru (TFA)₂((S)-BINAP]. The asymmetric hydrogenation was carried out at 60 ℃ under 18 bar of hydrogen for 12 hours. After cooling to room temperature, the pressure was released from the autoclave and a sample of the yellow reaction solution was analyzed to show>99% conversion to (S) -3- (tert-butoxycarbonyl-isopropyl-amino) -2- (4-chloro-phenyl) -propionic acid, with an S/R enantiomeric ratio of 99 to 1. The hydrogenation mixture was transferred to a 0.5L reactor with the aid of 10mL of ethanol. The reaction mixture was evaporated in vacuo at 45 ℃ to give a residual volume of 65 mL.

70ml of tert-butyl methyl ether were added at 20 ℃. A solution of sodium ethoxide in ethanol (21% (m/m), 9.5g, 29.4mmol) was then added dropwise with stirring at 45 ℃. The funnel was rinsed with 1.3g of ethanol. A precipitate was formed, which was stirred at the same temperature for 1 hour, followed by stirring at room temperature for 1 hour. The precipitated product was filtered off, washed with tert-butyl methyl ether/ethanol 1:1 mixture (13.6g) and tert-butyl methyl ether (16g), dried under vacuum until the weight was constant to yield sodium (S) -3- (tert-butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) propionate (9.5g) as white crystals in 89% yield and with S/R enantiomeric ratio 100 to 0%.

Example 3c

(S) -3- (tert-Butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) -propionic acid

In a glove box (O)₂Content 2ppm) to a 185ml autoclave were charged with 17.1g (50.0mmol) of (E) -2- (4-chlorophenyl) -3- [ (2-methylpropan-2-yl) oxycarbonyl-propan-2-ylamino]2-propenoic acid and 75ml ethanol. In a separate flask, 4.79mg (0.005mmol, S/C10' 000) [ Ru (TFA)₂((S)-BINAP]And 8.3ml of ethanol were treated with 1.67ml (0.10mmol) of 60 mmol of aqueous HCl, and the resulting suspension was stirred for 30 minutes and then added to the autoclave. After the autoclave had been sealed, the asymmetric hydrogenation was carried out at 60 ℃ for 12 hours under 18 bar of hydrogen. After cooling to room temperature, the pressure was released from the autoclave and a sample of the yellow reaction solution was analyzed to show 99.5% conversion to (S) -3- (tert-butoxycarbonyl-isopropyl-amino) -2- (4-chloro-phenyl) -propionic acid with an S/R enantiomeric ratio of 98.7 to 1.3.

Example 3d

(S) -3- (tert-Butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) -propionic acid

The procedure of example 3c was repeated using HBr as additive. The hydrogenation was carried out at 99.8% conversion and the desired (S) -acid was isolated in quantitative yield with an S/R enantiomeric ratio of 98.7: 1.3.

Example 3e

(S) -3- (tert-Butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) -propionic acid

In a glove box (O)₂Content 2ppm) to a 185ml autoclave were charged with 17.0g (50.0mmol) of (E) -2- (4-chlorophenyl) -3- [ (2-methylpropan-2-yl) oxycarbonyl-propan-2-ylamino]2-propenoic acid and 75ml ethanol. In a separate flask, 9.59mg (0.010mmol, S/C5' 000) [ Ru (TFA)₂((S)-BINAP]And 9.8ml of ethanol were treated with 0.20ml (0.20mmol) of 1 molar aqueous HCl solution, and the resulting suspension was stirred for 30 minutes and then added to the autoclave. In a sealed autoclaveAfter this, the asymmetric hydrogenation was carried out at 60 ℃ under 18 bar of hydrogen for 12 hours. After cooling to room temperature, the pressure was released from the autoclave and a sample of the yellow reaction solution was analyzed to show 99.7% conversion to (S) -3- (tert-butoxycarbonyl-isopropyl-amino) -2- (4-chloro-phenyl) -propionic acid with an S/R enantiomeric ratio of 99.0 to 1.0.

Example 3f

(S) -3- (tert-Butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) -propionic acid

The procedure of example 3f was repeated using LiBr as additive. The hydrogenation was carried out at 98.9% conversion and the desired (S) -acid was isolated in quantitative yield with an S/R enantiomeric ratio of 98.5: 1.5.

Example 4

(S) -3- (tert-Butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) -propionic acid

In a glove box (O)₂Content 2ppm) A35 ml autoclave equipped with a glass insert and a magnetic stirrer bar was charged with 400mg (1.18mmol) of (E) -2- (4-chlorophenyl) -3- [ (2-methylpropan-2-yl) oxycarbonyl-propan-2-ylamino]Prop-2-enoic acid, 5.92mg (0.00589mmol) [ Ru (TFA)₂((S)-BINAP)](S/C200) and 4ml of ethanol. The autoclave was sealed and pressurized with 20 bar of hydrogen and the asymmetric hydrogenation was carried out at 60 ℃ for 14 hours with stirring. After cooling to room temperature, the pressure was released from the autoclave and the ethanol solution was evaporated in vacuo to yield (S) -3- (tert-butoxycarbonyl-isopropyl-amino) -2- (4-chloro-phenyl) -propionic acid in quantitative yield and in S/R enantiomeric ratio 99: 1. Conversion is>＝99.9％。

Examples 5.1 to 5.17(S) or (R) -3- (tert-butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) propanoic acid

The procedure of example 4 was repeated using different chiral ruthenium catalysts to yield the corresponding (R) and (S) isomers of 3- (tert-butoxycarbonyl-isopropyl-amino) -2- (4-chloro-phenyl) -propionic acid. The results are shown in table 1 together with the catalyst,% conversion and S/R enantiomeric ratio. In all experiments (unless explicitly indicated in the footnotes), the reaction scale was 400mg, the temperature was 60 ℃, the hydrogen pressure was 20 bar and the reaction time was 14 hours at S/C ratio 200. The reactor was a 35ml autoclave. The indicated amounts of additives are intended to be relative to the amount of metal catalyst.

TABLE 1

35ml autoclave, 1.7g scale; S/C250, 22 hours. b)1.7g scale, S/C250, 14 hours; c)6.8g of substrate in a 50ml autoclave, S/C1500, 5 hours. d) 2.56mg of [ Ru (COD) (TFA) ] are stirred in 3ml of ethanol at 50 ℃ in a glove box₂]₂And 2.2 molar equivalents of chiral diphosphine for 3 hours to prepare the catalyst in situ.

Examples 6.1 to 6.8

(S) or (R) -3- (tert-butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) propionic acid

The following hydrogenations were carried out in a similar manner to examples 5.1-5.16 using various materials as additives to provide the (R) and (S) isomers of 3- (tert-butoxycarbonyl-isopropyl-amino) -2- (4-chloro-phenyl) -propionic acid in the purities and enantiomeric purities indicated in table 2. In all experiments (unless explicitly indicated in the footnotes), the reaction scale was 400mg, the temperature was 60 ℃ and the hydrogen pressure was 18-20 bar, during 4 hours at an S/C ratio of 200. The reactor was a 35ml autoclave. The indicated amounts of additives are intended to be relative to the amount of metal catalyst.

TABLE 2

Reaction time 14 hours for a); b) S/C4000, 18 hours, 6.8g scale, in a 185ml autoclave; c) S/C200, 14 hours, 1.18g Scale, 30ml autoclave, 20 bar H₂。

Examples 7.1 to 7.11

(S) or (R) -3- (tert-butoxycarbonyl (isopropyl) amino) -2- (4-chlorophenyl) propionic acid

The procedure of examples 5.1-5.16 was repeated, but the reaction conditions were varied in hydrogen pressure, concentration and solvent to yield the corresponding (R) and (S) isomers of 3- (tert-butoxycarbonyl-isopropyl-amino) -2- (4-chloro-phenyl) -propionic acid. The results are shown in table 3. In all experiments (unless explicitly indicated in the footnotes), the reaction scale was 400mg, in 4ml of solvent, the temperature was 60 ℃ and the reaction time was 14 hours at an S/C ratio of 200. The reactor was a 35ml autoclave, the catalyst was Ru (TFA)₂((S)-BINAP)。

TABLE 3

Reaction time 4 hours for a); b)200mg of substrate in 4ml of ethanol; c)600mg of substrate in 2ml of ethanol; d) 2.56mg of [ Ru (COD) (TFA) ] are stirred in 3ml of ethanol at 50 ℃ in a glove box₂]₂And 4.0mg of (S) -BINAP for 3 hours to prepare the catalyst in situ.

Example 8

(R) -4- (5-methyl-7-oxo-5, 6-dihydro-5H-cyclopenta [ d ] pyrimidin-4-yl) piperazine-1-carboxylic acid tert-butyl ester

(R) -3- (4, 6-dichloropyrimidin-5-yl) butanoic acid methyl ester

To a mixture of methyl (R) -3- (4, 6-dihydroxypyrimidin-5-yl) butyrate (1.00kg, 4.70mol), toluene (4.00L) and 2, 6-lutidine (0.550L, 4.70mol) was slowly added phosphorus oxychloride (0.960L, 10.6mol) at 50 ℃. The mixture was stirred at 70 ℃ for 24 hours. The solution was cooled to 0 ℃. While maintaining the internal temperature below 30 ℃, a 20% aqueous sodium hydroxide solution (about 40.0mol,1.60kg at 8.00L H₂0) to obtain a final pH value between 5 and 6. Ethyl acetate (2.50L) was added, stirred for 0.5 hour, and then the layers were separated. The aqueous phase was extracted with ethyl acetate (3X 1.00L). The organics were combined and washed with 1N hydrochloric acid (2X 2.50L) and brine (2.50L). The organic layers were combined and dried over sodium sulfate and filtered through a glass fiber filter. The solution was concentrated to about 3.00mL/g and diluted with acetonitrile to about 7.00 mL/g. This sequence was repeated twice to remove residual ethyl acetate and toluene (by¹H NMR analysis confirmed). The remaining crude solution was used directly in the next step without further purification or isolation.

(R) -3- (4, 6-diiodopyrimidin-5-yl) butanoic acid methyl ester

To a solution of methyl (R) -3- (4, 6-dichloropyrimidin-5-yl) butyrate (36.0g, 145mmol) in acetonitrile (540mL) was added sodium iodide (152g, 1.02 mol). The mixture was stirred at 25 ℃ for 30 minutes, then cooled to about 5 ℃. Methanesulfonic acid (9.41mL, 1.00 eq) was added over 5 minutes. The mixture was stirred at about 5 ℃ for 3 hours. The reactor was cooled to about 5 ℃ and N, N-diisopropylethylamine (20.3mL, 116mmol) was added. The mixture was stirred for 1 hour while allowing the mixture to warm to 20 ℃. Saturated sodium sulfite solution was added until no further color change was observed to remove iodine. Water (540mL) was added and the pH was adjusted to between about 5 and 7. The biphasic mixture was concentrated under reduced pressure at a temperature of less than 40 ℃ to remove acetonitrile. The aqueous suspension was filtered to give 48.8g (78% yield) of the product as an off-white solid.

(R) -4- (6-iodo-5- (4-methoxy-4-oxobutan-2-yl) pyrimidin-4-yl) piperazine-1-carboxylic acid tert-butyl ester

To a solution of (R) -methyl 3- (4, 6-diiodopyrimidin-5-yl) butyrate (212g, 491mmol) and Boc-piperazine (101g, 540mmol) in methanol (424mL) was added N, N-diisopropylethylamine (94.3mL, 540 mmol). The mixture was heated at 60 ℃ for 24 hours. The methanol was distilled off under reduced pressure at below 40 ℃. To the mixture was added 318mL of tetrahydrofuran. The above solvent exchange procedure was repeated twice. To the mixture was added 424mL of tetrahydrofuran, 212mL of saturated aqueous ammonium chloride solution, and 21.2mL of water. The organic layer was washed with 212mL (1.00 volume) of saturated aqueous ammonium chloride solution. This tetrahydrofuran solution was used in the next step without further purification (91% by weight yield).

(R) -3- (4- (4- (tert-butoxycarbonyl) piperazin-1-yl) -6-iodo-pyrimidin-5-yl) butanoic acid

To a solution of tert-butyl (R) -4- (6-iodo-5- (4-methoxy-4-oxobutan-2-yl) pyrimidin-4-yl) piperazine-1-carboxylate (219g, 0.447mol) in tetrahydrofuran (657mL) at 25 ℃ was added a solution of lithium hydroxide monohydrate (56.2g, 1.34mol) in 329mL of water. The mixture was stirred at 25 ℃ for 5 hours. The bottom aqueous layer was discarded. The mixture was acidified with 1N hydrochloric acid at 5 ℃ to give a final pH value of between about 1 and 2. The layers were separated. The top layer was then extracted with isopropyl acetate (440mL × 3), combined with the bottom layer, and washed with water (220mL × 2). The solvent was distilled off under reduced pressure at below 50 ℃. Residual isopropyl acetate was azeotroped with heptane at reduced pressure below 50 ℃. The product gradually precipitated out and was filtered to give an off-white to light yellow powder (196g, 84% yield).

(R) -4- (6-iodo-5- (4- (methoxy (methyl) amino) -4-oxobutan-2-yl) pyrimidin-4-yl) piperazine-1-methyl Tert-butyl ester

To a solution of (R) -3- (4- (4- (tert-butoxycarbonyl) piperazin-1-yl) -6-iodo-pyrimidin-5-yl) butyric acid (100g, 210mmol) in tetrahydrofuran (700mL) was added 1,1' -carbonyldiimidazole (40.9g, 252mmol) in portions. The reaction mixture was stirred at 20 ℃ for 1 hour and cooled to 5 ℃. N, O-dimethylhydroxylamine hydrochloride (41.0g, 420mmol) was added portionwise followed by N-methylmorpholine (6.94mL, 63.0 mmol). The mixture was stirred at 5 ℃ for about 1 hour, slowly warmed to room temperature, and stirred for 24 hours. Saturated aqueous ammonium chloride (500mL) and water (150mL) were added to give a clear phase separation. The organic layer was washed with saturated aqueous ammonium chloride (500mL) and brine (200 mL). Residual water was azeotropically removed by co-evaporation with tetrahydrofuran to reach less than 500 ppm. The product in the form of a solution in tetrahydrofuran was used in the next step without further purification or isolation (gravimetric yield: > 99%.

(R) -4- (5-methyl-7-oxo-6, 7-dihydro-5H-cyclopenta [ d)]Pyrimidin-4-yl) piperazine-1-carboxylic acid tert-butyl ester

A solution of tert-butyl (R) -4- (6-iodo-5- (4- (methoxy (methyl) amino) -4-oxobutan-2-yl) pyrimidin-4-yl) piperazine-1-carboxylate (109g, 210mmol) in tetrahydrofuran (600mL) was purged with nitrogen for 30 minutes. A solution of isopropyl magnesium chloride (159mL, 210mmol, 1.32M in tetrahydrofuran) was added dropwise at-15 ℃. The mixture was stirred at-10 ℃ for 1 hour and slowly transferred to 20 wt% cold aqueous ammonium chloride (600mL) with stirring while maintaining the internal temperature below 10 ℃. The organic layer was then washed with saturated aqueous ammonium chloride (500 mL). The tetrahydrofuran was distilled off under reduced pressure at below 40 ℃. Methyl tert-butyl ether (350mL) was added slowly while maintaining the internal temperature between 35 ℃ and 40 ℃, followed by heptane (350 mL). The mixture was slowly cooled to 20 ℃ and the product gradually precipitated out during the process. The slurry was filtered and the filter cake was dried under vacuum at 40 ℃ to give a grey solid (52.3g, 75% yield over two steps).¹H NMR(300MHz,CDCl₃)δ8.73(s,IH),3.92-3.83(m,2H),3.73-3.49(m,7H),2.96(dd,J＝16.5,7.2Hz,1H),2.33(dd,J＝16.5,1.8Hz,IH),1.50(s,9H),1.32(d,J＝6.9Hz,3H)。C₁₇H₂₅N₄0₃HRMS calculated of (a): [ M + H ]]⁺333.1921, found: 333.1924.

example 9

4- [ (5R,7R) -7-hydroxy-5-methyl-6, 7-dihydrocyclopenta [ d ] pyrimidin-4-yl ] piperazine-1-carboxylic acid tert-butyl ester

3g of 4- [ (5R) -5-methyl-7-oxo-5, 6-dihydrocyclopenta [ d ] are formed under vigorous stirring]Pyrimidin-4-yl]Piperazine-1-carboxylic acid tert-butyl ester in 21ml of aqueous buffer (100mM 2- (N-morpholino) ethanesulfonic acid, pH 5.8), 6ml of 2-propanol and 3mg of the oxidative cofactor NADP [ Roche ]]Reduced yellow suspension of (1). The reaction solution was heated to 40 ℃ and stirred for 5 minutes, and thenThe reduction was started by adding 30mg KRED-X1-P1B 06. The pH was adjusted from 5.6 to 5.8. During the course of the reaction at 40 ℃ achieving almost complete conversion (IPC: 0.6 area% of educt) in 21.5 hours, the pH increased to 6.4. To the reaction was added 30ml of isopropyl acetate and stirred vigorously for 15 minutes. Phase splitting occurs spontaneously. The separated aqueous phase was extracted twice with 50ml of isopropyl acetate, for a total of 100ml of isopropyl acetate. The combined organic phases were over MgSO₄Dried, filtered and evaporated under vacuum at 50 ℃ to yield a light red foam at 3.07g (102%) as the title compound as crude product containing about 4% isopropyl acetate. GC-EI-MS: 334.2(M + H)⁺(ii) a Chiral HPLC: 99.88% (R, R), 0.12% (R, S) [254 nm; chiralpak IC-3; 150 x 4.6mm, 3 μm, flow rate 0.8ml, 30 ℃, a: 60% n-heptane, B: 40% EtOH +0.1DEA, 0-15 min 100% B, 15-17 min 100% B, 17.1 min 40% B](ii) a Chemical purity HPLC: 99.2 area% (containing 0.6 area% of educt).¹H NMR(600MHz,CDCl₃) δ ppm 1.17-1.22(m,3H)1.45-1.51(m,9H)2.02(s,1H)2.12-2.24(m,2H)3.43-3.83(m,9H)3.85-4.08(m,1H)5.12(t, J ═ 7.2Hz,1H)8.53(s,1H) (containing about 4% isopropyl acetate).

Examples 10.1 to 10.6

4- [ (5R,7R) -7-hydroxy-5-methyl-6, 7-dihydrocyclopenta [ d ] pyrimidin-4-yl ] piperazine-1-carboxylic acid tert-butyl ester

For examples 9.1-9.6, the procedure of example 9 was repeated, but varying the cofactor (NADP [ Roche ]) ratios as indicated in the table below, and applying a different ketoreductase variant, i.e., applying KRED-X1.

TABLE 4

Example 11

4- [ (5R,7R) -7-hydroxy-5-methyl-6, 7-dihydrocyclopenta [ d ] pyrimidin-4-yl ] piperazine-1-carboxylic acid tert-butyl ester

Under vigorous stirring, 6g of 4- [ (5R) -5-methyl-7-oxo-5, 6-dihydrocyclopenta [ d ] are formed]Pyrimidin-4-yl]Piperazine-1-carboxylic acidTert-butyl ester in 18ml of aqueous buffer (100mM 2- (N-morpholino) ethanesulfonic acid, pH 5.8), 6ml of 2-propanol and 6mg of the oxidative cofactor NADP [ Roche ]]Reduced yellow suspension of (1). The reaction solution was heated to 40 ℃ and stirred for 5 minutes, and then, reduction was started by adding 60mg KRED-X1-P1B 06. The pH was adjusted from 5.5 to 5.8. During the course of the reaction at 40 ℃ to achieve almost complete conversion in 2 days (IPC: 1 day 1.3 area% educt, 2 days 1.2 area% educt), the pH was increased to 6.0. To the reaction was added 30ml of isopropyl acetate and stirred vigorously for 15 minutes. Phase splitting occurs spontaneously. The separated aqueous phase was extracted twice with 50ml of isopropyl acetate, for a total of 100ml of isopropyl acetate. The combined organic phases were over MgSO₄Dried, filtered and evaporated under vacuum at 50 ℃ to yield a light red foam at 6.02g (99.7%) as the crude product of the title compound containing about 4% isopropyl acetate. GC-EI-MS: 334.2(M + H)⁺(ii) a Chiral HPLC: 99.88% (R, R), 0.12% (R, S) [254 nm; chirapakl IC-3; 150 x 4.6mm, 3 μm, flow rate 0.8ml, 30 ℃, a: 60% n-heptane, B: 40% EtOH +0.1DEA, 0-15 min 100% B, 15-17 min 100% B, 17.1 min 40% B](ii) a Chemical purity HPLC: 98.4 area% (containing 1.3 area% educt).¹H NMR(600MHz,CDCl₃) δ ppm 1.2(d, J ═ 7.1Hz 3H)1.49(s,9H)2.14-2.23(m,2H)3.46-3.59(m,5H)3.64(ddd, J ═ 13.1,6.9,3.3Hz,2H)3.78(ddd J ═ 13.1,7.2,3.3Hz,2H)5.12(t, J ═ 7.2Hz,1H)8.53(s,1H) (containing about 4% isopropyl acetate).

Example 12

4- [ (5R,7R) -7-hydroxy-5-methyl-6, 7-dihydrocyclopenta [ d ] pyrimidin-4-yl ] piperazine-1-carboxylic acid tert-butyl ester

3g of 4- [ (5R) -5-methyl-7-oxo-5, 6-dihydrocyclopenta [ d ] are formed under vigorous stirring]Pyrimidin-4-yl]Piperazine-1-carboxylic acid tert-butyl ester in 21ml of an aqueous buffer solution (100mM potassium dihydrogen phosphate, pH 7.2; 2mM magnesium chloride), 6ml of 2-propanol and 3mg of the oxidative cofactor NADP [ Roche ]]Reduced yellow suspension of (1). The reaction solution was heated to 40 ℃ and stirred for 5 minutes, and then, reduction was started by adding 30mg KRED-X1-P1B 06. The pH was adjusted from 7.5 to 7.2. A reaction to almost complete conversion (IPC: 0.8 area% educt) was achieved at 40 ℃ in 18.5 hDuring the course of the reaction, the pH was lowered to 7.15. To the reaction was added 30ml of isopropyl acetate and stirred vigorously for 15 minutes. Phase splitting occurs spontaneously. The separated aqueous phase was extracted twice with 50ml of isopropyl acetate, for a total of 100ml of isopropyl acetate. The combined organic phases were over MgSO₄Dried, filtered and evaporated under vacuum at 50 ℃ to yield a light red foam at 3.06g (102%) as the crude product containing about 4% isopropyl acetate of the title compound. GC-EI-MS: 334.2(M + H)⁺(ii) a Chiral HPLC: 99.76% (R, R), 0.24% (R, S) [254 nm; chirapakl IC-3; 150 x 4.6mm, 3 μm, flow rate 0.8ml, 30 ℃, a: 60% n-heptane, B: 40% EtOH +0.1DEA, 0-15 min 100% B, 15-17 min 100% B, 17.1 min 40% B](ii) a Chemical purity HPLC: 98.9 area% (containing 0.8 area% educt).¹H NMR(600MHz,CDCl₃) δ ppm 1.16-1.22(m,3H)1.45-1.53(m,9H)2.12-2.25(m,2H)3.42-3.86(m,9H)4.13(br.s.,1H)5.12(t, J ═ 7.2Hz,1H) 8.44-8.59 (m,1H) (containing about 4% isopropyl acetate).

Examples 13.1 to 13.7

4- [ (5R,7R) -7-hydroxy-5-methyl-6, 7-dihydrocyclopenta [ d ] pyrimidin-4-yl ] piperazine-1-carboxylic acid tert-butyl ester

10mg of 4- [ (5R) -5-methyl-7-oxo-5, 6-dihydrocyclopenta [ d ] dissolved in a mixture of 50. mu.l of DMSO and 50. mu.l of 2-propanol was added]Pyrimidin-4-yl]Piperazine-1-carboxylic acid tert-butyl ester to deep well plate containing 300. mu.l buffer (100mM MES, 2mM MgCl)₂(ii) a pH 5.8), 1mg NADP and KRED-X1. After 1.5 hours of shaking at room temperature, 0.5ml of MeOH was added to each well and analyzed by HPLC. The results of the best variants are listed in the table below.

TABLE 5

Examples	Ketoreductase variants	The product (R, S): (R, R)
			13.1	KRED-X1.1-P1F01	0.00:85:96
13.2	KRED-X1.1-P1H10	0.00:81.87
			13.3	KRED-X1.1-P1C08	0.00:78.20
13.4	KRED-X1.1-P1C04	0.03:94.83
			13.5	KRED-X1.1-P1G11	0.03:94.06
13.6	KRED-X1.1-P1C11	0.04:86.69
			13.7	KRED-X1-P1B06	0.08:79.80

Example 13a

4- [ (5R,7R) -7-hydroxy-5-methyl-6, 7-dihydrocyclopenta [ d ] pyrimidin-4-yl ] piperazine-1-carboxylic acid tert-butyl ester

A suspension of 50g (150mmol) of tert-butyl 4- [ (5R) -5-methyl-7-oxo-5, 6-dihydrocyclopenta [ d ] -pyrimidin-4-yl ] piperazine-1-carboxylate in 100ml of aqueous buffer (100mM potassium dihydrogen phosphate, pH 7.2), 78g of 2-propanol and 50mg of NAD (75. mu. mol) was formed under vigorous stirring. The reduction was started by adding 500mg KRED-X1.1-P1F 01. The reaction mixture was sparged with nitrogen and heated to 40 ℃ for 22 hours. After the reaction was complete, 174g of isopropyl acetate were added, stirred, the phases were split and the aqueous phase was removed. The aqueous phase is re-extracted with 174g of isopropyl acetate. The aqueous phase was removed and the organic phases were combined and concentrated in vacuo at 35 ℃ to a final volume of 115 mL. 212g of heptane were added over 1 hour at the same temperature, the suspension was aged for 1 hour and cooled to 10 ℃ over 6 hours. The suspension was filtered and washed with 68g heptane. After drying the filter cake at 50 ℃ for 4 hours, 41.1g (82% yield, 100% area purity) of white crystals were obtained.

Example 13b

4- [ (5R,7R) -7-hydroxy-5-methyl-6, 7-dihydrocyclopenta [ d ] pyrimidin-4-yl ] piperazine-1-carboxylic acid tert-butyl ester

40g (150mmol) of 4- [ (5R) -5-methyl-7-oxo-5, 6-dihydrocyclopenta [ d ] are formed under vigorous stirring]-pyrimidin-4-yl]Piperazine-1-carboxylic acid tert-butyl ester in 240ml of an aqueous buffer solution (containing 3.3g KH)₂PO₄And 8.4g K₂HPO₄) 26g glucose and 40mg NAD. The reduction was warmed to 35 ℃ and started by adding 400mg KRED-X1.1-P1F01 and 400mg GDH-101. Over the course of the reaction (26 h), the pH was maintained at 7.0 using 58.8mL of aqueous KOH (10% (m/m)). After the reaction was complete, 290g isopropyl acetate and 117g NaSCN were added, stirred, the phases were split and the aqueous phase was removed. The organic phase was washed with 200g of water and filtered using a filtrox filter plate and the aqueous phase was washed with 175g of isopropyl acetate. The combined organic phases were concentrated in vacuo at 25 ℃ to a final volume of 100 mL. 383g of heptane were added over 1 hour at 25 ℃. The suspension was cooled to 0 ℃ over 30 minutes and aged for 30 minutes. The suspension was filtered and washed with 91g heptane. After drying the filter cake at 50 ℃ for 16 hours, 30.9g (76% yield, 100% area purity) of white crystals were obtained.

Example 14

((S) -tert-butyl 2- (4-chlorophenyl) -3- (4- ((5R,7R) -7-hydroxy-5-methyl-6, 7-dihydro-5H-cyclopenta [ d ] pyrimidin-4-yl) piperazin-1-yl) -3-oxopropyl) (isopropyl) carbamate

A three-necked 500mL reactor equipped with a mechanical stirrer, nitrogen inlet, and thermometer was charged with tert-butyl 4- ((5R,7R) -7-hydroxy-5-methyl-6, 7-dihydro-5H-cyclopenta [ d ] pyrimidin-4-yl) piperazine-1-carboxylate (16.7g, 52.5mmol) and 2-propanol (65 mL). The solution was heated to 55 ℃. 2-propanol (24.6g, 140mmol) containing 20.8% (m/m) HCl was then added over 10 minutes at 55 ℃. The suspension was stirred until the reaction was complete. The reaction mixture was cooled to 10 ℃ and 4-methylmorpholine (32.9g, 325mmol) was added. The mixture was stirred at 15 ℃ for 30 minutes. (S) -3- ((tert-butoxycarbonyl) (isopropyl) amino) -2- (4-chlorophenyl) propanoic acid sodium salt (19.1g, 52.5mmol) and 2-propanol (73g) were added and the reaction mixture was cooled to 5 ℃. Propane phosphonic anhydride (T3P) (50 w% (m/m) in toluene) (35g, 57.3mmol) was added at a rate to maintain the temperature at 5 ℃.

After the reaction was complete, 20g of water was added. The solution was concentrated by distillation at 45 ℃ and 150 mbar to a final volume of 100 mL. Toluene (260g) was added. The solution was concentrated again by distillation at 45 ℃ and 150 mbar until the final volume was 300 mL. Water (150g) was added and the suspension was stirred for 15 minutes. The phases were separated for 15 minutes and the aqueous phase was removed. Water (100g) was added and the suspension was stirred for 15 minutes. The phases were separated for 15 minutes and the aqueous phase was removed. Water (100g) was added again and the suspension was stirred for 15 minutes. The phases were separated for 15 minutes and the aqueous phase was removed. The solution was concentrated by distillation at 45 ℃ and 150 mbar to a final volume of 100 mL. N-heptane (34g) was added and the solution was cooled to 0 ℃ over 1 hour to allow ((S) -2- (4-chlorophenyl) -3- (4- ((5R,7R) -7-hydroxy-5-methyl-6, 7-dihydro-5H-cyclopenta [ d ] to stand]Pyrimidin-4-yl) piperazin-1-yl) -3-oxopropyl) (isopropyl) carbamic acid tert-butyl ester. N-heptane (170g) was further added. The suspension was aged for 2 hours, filtered and washed with a mixture of toluene (6.4g) and n-heptane (29.2g), thenWashed twice with heptane (68.4 g each). Drying the filter cake at ≤ 55 deg.C to give ((S) -2- (4-chlorophenyl) -3- (4- ((5R,7R) -7-hydroxy-5-methyl-6, 7-dihydro-5H-cyclopenta [ d ] as an off-white solid]Pyrimidin-4-yl) piperazin-1-yl) -3-oxopropyl) (isopropyl) carbamic acid tert-butyl ester isolated 23.9g, 86% yield. (¹H NMR(600MHz,CDCl₃)δppm 0.68(br.s.,3H)0.94-1.08(m,3H)1.14(d,J＝7.0Hz,3H)1.47(s,10H)2.06-2.27(m,2H)3.30(br.s.,1H)3.38-3.53(m,5H)3.56-3.73(m,4H)3.78(br.s.,3H)4.62(br.s.,1H)5.10(t,J＝7.1Hz,1H)7.24(s,1H)8.49(s,1H)。

Example 15

(S) -2- (4-chlorophenyl) -1- (4- ((5R,7R) -7-hydroxy-5-methyl-6, 7-dihydro-5H-cyclopenta [ d ] pyrimidin-4-yl) piperazin-1-yl) -3- (isopropylamino) propan-1-one monohydrochloride

To a 500mL reactor equipped with a mechanical stirrer, nitrogen inlet, thermometer, and pH meter was added ((S) -2- (4-chlorophenyl) -3- (4- ((5R,7R) -7-hydroxy-5-methyl-6, 7-dihydro-5H-cyclopenta [ d)]Pyrimidin-4-yl) piperazin-1-yl) -3-oxopropyl) (isopropyl) carbamic acid tert-butyl ester (50g) and 2-propanol (128 g). The solution was heated to 50 ℃. A solution of HCl in 2-propanol (21 wt% (m/m), 46.7g) was added at 50 ℃. The solution was maintained at 50 ℃ until the reaction was complete and the mixture was cooled to 25 ℃. A solution of ammonia in 2-propanol (2M, 66.6g, 1.66 eq) was added over about 1 hour until a pH of 6.7 was reached. The suspension was cooled to 0 ℃ and filtered. The filter cake was washed with 2-propanol (39 g). The filtrate was concentrated by distillation at 50 ℃ and 150 mbar to a final volume of 100 mL. Ethyl acetate (130g) was added to the solution. The slurry was solvent switched at 40 ℃ using ethyl acetate (670g) at constant volume (300 mL). The suspension was cooled to 5 ℃ and the slurry was filtered. The filter cake was washed with EtOAc (105mL) and dried under vacuum at 100 ℃ for 16H to provide (S) -2- (4-chlorophenyl) -1- (4- ((5R,7R) -7-hydroxy-5-methyl-6, 7-dihydro-5H-cyclopenta [ d ] as an off-white solid]Pyrimidin-4-yl) piperazin-1-yl) -3- (isopropylamino) propan-1-oneKetone monohydrochloride: 36.4g (82% yield). (¹H NMR(600MHz,D₂O)δppm 0.92(d,J＝7.1Hz,3H)1.23(t,J＝6.4Hz,6H)1.89-2.15(m,2H)2.85-3.06(m,1H)3.17-3.59(m,10H)3.83(d,J＝10.5Hz,2H)4.33(dd,J＝8.5,4.9Hz,1H)4.98(t,J＝7.0Hz,1H)7.23(d,J＝8.5Hz,2H)7.36(d,J＝8.7Hz,2H)8.10-8.35(m,1H).LCMS[M+H]⁺458.2)。

Example 16

(S) -2- (4-chlorophenyl) -1- (4- ((5R,7R) -7-hydroxy-5-methyl-6, 7-dihydro-5H-cyclopenta [ d ] pyrimidin-4-yl) piperazin-1-yl) -3- (isopropylamino) propan-1-one monohydrochloride

To a 500mL reactor equipped with a mechanical stirrer, nitrogen inlet, thermometer, and pH meter was added tert-butyl ((S) -2- (4-chlorophenyl) -3- (4- ((5R,7R) -7-hydroxy-5-methyl-6, 7-dihydro-5H-cyclopenta [ d ] pyrimidin-4-yl) piperazin-1-yl) -3-oxopropyl) (isopropyl) carbamate (50g) and 1-propanol (131 g). The solution was heated to 60 ℃. A solution of HCl in 1-propanol (22 wt% (m/m), 38.0g) was added at 60 ℃. The solution was maintained at 50 ℃ until the reaction was complete and the mixture was cooled to 25 ℃. Aqueous NaOH (28%) (16g) was added until pH6 was reached. The suspension was concentrated in vacuo at 60 ℃ until a final volume of 100mL was reached. The suspension is cooled to 20 ℃,90 g of ethyl acetate are added and filtered with a filtrox plate. The reactor and filtration unit were washed with 41g of 1-propanol/ethyl acetate. The solution was filtered through a charcoal filter pad at 20 ℃. The reactor and filter were rinsed with 82g of 1-propanol/ethyl acetate. The solution was concentrated in vacuo at 60 ℃ to a final volume of 300 mL. The distillation was continued at 60 ℃ and at the same time 1260g of ethyl acetate were added, keeping the volume constant.

The suspension was cooled to 5 ℃ and the slurry was filtered. The filter cake was washed with EtOAc (105mL) and dried under vacuum at 60 ℃ for 16 hours to provide (S) -2- (4-chlorophenyl) -1- (4- ((5R,7R) -7-hydroxy-5-methyl-6, 7-dihydro-5H-cyclopenta [ d ] pyrimidin-4-yl) piperazin-1-yl) -3- (isopropylamino) propan-1-one monohydrochloride as an off-white solid: 36.5g (81% yield, 91.4% (m/m) purity, 99.9% (area) determination).