阅读说明：本技术 杂环硼酸化合物的杂质及其控制方法 (Impurities of heterocyclic boronic acid compounds and methods of controlling the same ) 是由 朱云龙 郑直 周婷 叶杉 卿亚丽 黄雪惠 吕裕斌 于 2019-11-29 设计创作，主要内容包括：本发明提供了度格列汀L-酒石酸盐的杂质(I)、(II)及其制备方法。(I)和(II)为度格列汀L-酒石酸盐的氧化杂质,在度格列汀L-酒石酸盐制备及放置过程中均会产生。本发明同时提供了工业化生产度格列汀L-酒石酸盐时,在降低总杂的同时控制杂质(I)和(II)含量的方法,提高了度格列汀L-酒石酸盐的质量标准,保证其用药安全。另外,杂质(I)和(II)作为参比标准或对照品,可用于度格列汀或其L-酒石酸盐原料药和/或制剂中的质量控制和研究。<Image he="312" wi="700" file="DDA0002294662780000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The invention provides impurities (I) and (II) of duloxetine L-tartrate and a preparation method thereof. (I) And (II) an oxidation impurity which is dulagliptin L-tartrate, both produced during the preparation and placement of dulagliptin L-tartrate. The invention also provides a method for controlling the contents of the impurities (I) and (II) while reducing the total impurities during the industrial production of the duloxetine L-tartrate, so that the quality standard of the duloxetine L-tartrate is improved, and the medication safety of the duloxetine L-tartrate is ensured. In addition, the impurities (I) and (II) are used as reference standards or reference substances and can be used for quality control and research in the dulagliptin or L-tartrate bulk drug and/or preparation thereof.)

1. Heterocyclic boronic acid compound dulagliptin L-tartrate impurities (I) and (II), characterized in that: the impurities (I) and (II) have the following structures:

2. the process for the preparation of the impurity (II) according to claim 1, wherein: prepared by oxidizing duloxetine L-tartrate with hydrogen peroxide:

3. the method of claim 2, wherein: the concentration of the hydrogen peroxide is 0.1%, and the oxidation is carried out at room temperature for more than 90 hours.

4. A process for the preparation of duloxetine L-tartrate with reduced levels of impurities (I) and (II) as described in claim 1, wherein: when preparing duloxetine L-tartrate according to the route shown in the following formula,

wherein PG is an amine protecting group which can be removed by catalytic hydrogenation, and is preferably-Cbz, -PMB, -Bn; r¹、R²Is a boronic acid protecting group, each independently selected from methyl, ethyl, n-propyl, isopropyl or n-butyl, or R¹、R²Together with the attached oxygen atom form a cyclic boronic acid diester;

the method comprises the following steps:

(1) the intermediate 2 is subjected to catalytic hydrogenation reaction under the conditions of 10 weight percent of palladium carbon, 7-10 times of methanol by mass volume and 0.3-0.5MPa of hydrogen pressure;

(2) and (2) post-treating the product obtained in the step (1) in an inert gas atmosphere: filtering with microcrystalline cellulose and anhydrous sodium sulfate, concentrating the filtrate under reduced pressure to remove part of solvent, adding ethyl acetate, and concentrating continuously, wherein the concentration process is circulated for 3-4 times;

(3) adding the solution of ethyl acetate after concentration obtained in the step (2) and crystallizing at 0 ℃ to obtain an intermediate 1;

(4) and reacting the intermediate 1 with phenylboronic acid and L-tartaric acid in a mixed solution of normal hexane and water, and extracting the reaction liquid by using an ether solvent to obtain the duloxetine L-tartrate.

5. The method of claim 4, wherein: the structure of the cyclic boric acid diester is as follows:

6. the method of claim 4, wherein: in the catalytic hydrogenation reaction in the step (1), hydrogen is used for replacing reaction system gas in the reaction process.

7. The method of claim 4, wherein: the concentration in the step (2) is carried out until the residual volume is 1.5 to 3 times, preferably 1.5 to 2 times and more preferably 1.75 times of the mass of the intermediate 2; after concentration, ethyl acetate is added in a volume of 2 to 4 times, preferably 2.5 times, the mass of intermediate 2.

8. The method of claim 4, wherein: the volume of the n-hexane used in the step (4) is more than 8 times of the mass of the intermediate 1.

9. The method of claim 4, wherein: in the step (4), the ether solvent is methyl tert-butyl ether.

10. The use of impurities (I) and (II) as defined in claim 1 as standards or controls for quality control and research on the drug substance and/or formulation of duloxetine or its L-tartrate salt.

Technical Field

The invention belongs to the technical field of medical analysis and preparation, and particularly relates to impurities (I) and (II) of a heterocyclic boronic acid compound duloxetine L-tartrate, a preparation method of the impurities (I) and (II), and a quality control method of the impurities (I) and (II).

Background

Duloxetine L-Tartrate (Dutogliptin L-Tartrate) is a selective DPP-IV inhibitor, currently in clinical stage, and can be used for glucose regulation in diabetic patients. The duloxetine L-tartrate is a heterocyclic boric acid compound, and has the following structure:

the rivogliptin L-tartrate is white to yellowish solid powder, is easily soluble in methanol and is very slightly soluble in isopropanol. Because of its high water absorption, the solid material contains about 10% water. Meanwhile, the duloxetine L-tartrate is unstable in property and is easy to degrade under acidic and alkaline conditions to generate impurities.

Patents CN101232890, CN101679238 and WO2010107809 disclose preparation methods of duloxetine L-tartrate. Carrying out hydrogenation reduction on the intermediate (2-I), removing a-Cbz protecting group on N to obtain an intermediate (1-I), then removing a borate blocking group in a phenylboronic acid solution, and simultaneously forming a salt with L-tartaric acid to obtain duloxetine L-tartrate:

in the above two reactions, various impurities are generated. However, no literature reports about related impurities and control methods of the gliptin or the L-tartrate thereof are available at present. The inventors of the present application, when preparing duloxetine L-tartrate according to the above route, found that both reactions resulted in impurities with a relative retention time RRT1.09 (as measured by the liquid phase detection method of duloxetine L-tartrate). More importantly, different batches produced different amounts of the impurity, and various recrystallization purification conditions had poor removal of the impurity. If the structure of the impurity cannot be determined and the source of the impurity is further estimated, the content of the impurity cannot be controlled, and the stability of the quality of the drug cannot be ensured. Therefore, it is very important to confirm the structure of the RRT1.09 impurity and control the content of the impurity.

Due to the fact that more impurities are generated in the synthesis process of dulagliptin, the separation and identification work difficulty of each impurity is high. Since the amount of the produced RRT1.09 impurity is uncontrollable and has the same polarity as the duloxetine, the separation and identification work of the impurity has great difficulty, and a proper method must be found for identification and confirmation to further control the content of the impurity.

Disclosure of Invention

The invention aims to provide impurities (I) and (II) of a heterocyclic boronic acid compound duloxetine L-tartrate, optimize a process for preparing the duloxetine L-tartrate, and obtain the duloxetine L-tartrate with less total impurities while controlling the contents of the two impurities, so that the duloxetine L-tartrate can simultaneously meet the requirements of industrial production and the quality specification of medicines. The invention provides a preparation method of impurity (II), and the impurity (II) is prepared. The impurity (II) is L-tartrate of the impurity (I), and peak positions of the impurities (I) and (II) are the same under the detection condition, so the impurities (I) and (II) can be used as a standard substance or a reference substance for detecting the content of the impurities (I) and (II) in the raw material drug or preparation of the digliptin or the L-tartrate thereof so as to carry out quality control and research on the impurity (I) and the impurity (II).

The purpose of the invention can be realized by the following technical scheme:

the invention provides impurities (I) and (II) of heterocyclic boronic acid compound duloxetine L-tartrate, the impurities (I) and (II) having the following structures, respectively:

impurities (I) and (II) are oxidation impurities, which can be generated in the preparation process, and meanwhile, duloxetine products can be generated by degradation in the placing process. In order to control the content, research and control on the preparation process or the storage condition are needed.

The route for preparing duloxetine L-tartrate by the inventors of the present application is shown as follows:

in the early stage of the research, the present inventors have conducted intensive studies on the purification of the product obtained from the hydrogenation reaction in order to reduce the content of each impurity, and have attempted the purification effects of various solvents at different temperatures. The solvents used include: dichloromethane/ethyl acetate, dichloromethane/n-hexane, dichloromethane/isopropyl acetate, dichloromethane/methyl tert-butyl ether, dichloromethane/ethyl acetate/n-hexane, ethyl acetate/n-hexane, ethyl acetate/acetonitrile, tetrahydrofuran/n-hexane, isopropyl acetate/n-hexane, methanol/n-hexane, acetonitrile, methyl tert-butyl ether, isopropyl acetate. Among them, the best results can be obtained when using ethyl acetate for purification, and the specific process and purification parameters are as described in patent CN 101232890.

However, as research progresses and perfection progresses, when more suitable detection conditions are used, it is found that a plurality of impurities which are not detected before exist in the product purified under the above optimum conditions, so that the purification conditions need to be screened again.

Through a large number of screening experiments, it has been found that it is difficult to obtain satisfactory hydrogenation-reduction products in high yield and purity. Relatively good purification effect can be obtained only by changing the crystallization process, using THF and ethyl acetate mixed solvent for recrystallization and strictly controlling the volume and temperature of the solvent in each crystallization process.

However, despite tight control, the impurities of RRT1.09 (relative to the position of the peak of duloxetine) are still at high levels. Further, the present inventors have found that the content of the impurity does not decrease or increase when recrystallization is performed using a solvent containing tetrahydrofuran. The content of the impurities can not be obviously reduced by using other solvents, such as ethyl acetate, dichloromethane and the like for recrystallization again. It is hypothesized that this impurity may be an oxidation impurity, which is elevated during purification with tetrahydrofuran due to the peroxide contained in the tetrahydrofuran solvent.

To verify this estimation, the structure of the impurity was confirmed, and the synthesis of the impurity was investigated, and finally the structure of the impurity was confirmed.

The invention also provides a preparation method of the impurity (II), which is prepared by oxidizing duloxetine L-tartrate with hydrogen peroxide:

in a preferred embodiment, the concentration of the hydrogen peroxide is 0.1%, and the oxidation is performed at room temperature for 90 hours or more.

The mass spectrum of impurity (II) is shown in figure 1, and the molecular ion peak M/z is 214.1540 (M + H) shown in figure 1⁺Peak, consistent with the theoretical molecular weight of 213.1477 for the free base of impurity (II).

The hydrogen spectrum and carbon spectrum of impurity (II) are shown in figure 2 and figure 3 respectively. The hydrogen spectrum data and the carbon spectrum data can reasonably assign hydrogen and carbon on the structural formula.

And (3) taking the impurity (II) as a reference substance, taking the duloxetine L-tartrate which is placed in the air for a long time as a sample, and injecting the sample under the condition of duloxetine L-tartrate detection. Through detection, the peak position of the impurity (II) is basically coincided with the impurity of RRT1.09 corresponding to the main peak of duloxetine, and the impurity of RRT1.09 is verified to be the oxidized impurity.

And (3) dissociating the impurity (II) under the alkaline condition, and removing the L-tartaric acid to obtain the impurity (I). When detected, the impurity (I) and the impurity (II) peak at the same time.

In order to avoid the generation of oxidation impurities, the inventors of the present invention did not use ether solvents such as tetrahydrofuran for purification after the hydrogenation reaction was completed. Meanwhile, in order to meet the requirements of high product purity and low content of oxidized impurities, the process conditions need to be continuously optimized.

The invention also provides a method for preparing the high-purity gliptin L-tartrate, and the method for preparing the high-purity gliptin L-tartrate can effectively control the generation of oxidized impurities and reduce the generation of other impurities. The method uses a process route shown as the following formula, and adopts the process conditions of the steps (1) to (4):

wherein PG is an amine protecting group which can be removed by catalytic hydrogenation, and is preferably-Cbz, -PMB, -Bn; r¹、R²Is a boronic acid protecting group, each independently selected from methyl, ethyl, n-propyl, isopropyl or n-butyl, or R¹、R²Together with the attached oxygen atom form a cyclic boronic acid diester;

(1) the intermediate 2 is catalytically hydrogenated under the conditions of 10 percent of palladium carbon by weight, 7 to 10 times of methanol by mass volume and 0.3 to 0.5MPa of hydrogen pressure;

(2) and (2) post-treating the product obtained in the step (1) in an inert gas atmosphere: filtering with microcrystalline cellulose and anhydrous sodium sulfate, concentrating the filtrate under reduced pressure to remove part of solvent, adding ethyl acetate, and concentrating continuously, wherein the concentration process is circulated for 3-4 times;

(3) adding the solution of ethyl acetate after concentration obtained in the step (2) and crystallizing at 0 ℃ to obtain an intermediate 1;

(4) and reacting the intermediate 1 with phenylboronic acid and L-tartaric acid in a mixed solution of normal hexane and water, and extracting the reaction liquid by using an ether solvent to obtain the duloxetine L-tartrate.

In a preferred embodiment, the cyclic boronic acid diester structure is:

in a preferred embodiment, during the catalytic hydrogenation reaction of step (1), the reaction system gas is replaced with hydrogen.

The inventor of the present application finds that, in the catalytic hydrogenation reaction process in step (1), impurity PHX2044 is generated, and the structure thereof is as follows:by replacing the gases of the reaction system with hydrogen during the reaction, for example once per hour and twice per hour, the production of the impurities is greatly reduced and the purity of the hydrogenated product is improved.

In a preferred embodiment, the concentration in step (2) means that the remaining volume after each concentration is 1.5 to 3 times, preferably 1.5 to 2 times, more preferably 1.75 times the mass of intermediate 2; after concentration, ethyl acetate is added in a volume of 2 to 4 times, preferably 2.5 times, the mass of intermediate 2.

In a preferred embodiment, the volume of n-hexane used in step (4) is 8 times or more the mass of intermediate 1.

In a preferred embodiment, the ether-based extraction solvent used in step (4) is methyl tert-butyl ether.

The high-purity duloxetine L-tartrate in the invention refers to duloxetine L-tartrate in which the sum of the contents of impurities (I) and (II) is less than 0.15% and the total impurity content is less than 0.5%.

The dulagliptin L-tartrate impurities (I) and (II) provided by the invention can be used as a standard substance or a reference substance for quality control and research on a dulagliptin or L-tartrate bulk drug and/or preparation thereof.

Compared with the prior art, the invention has the following beneficial effects:

1) the application confirms and characterizes the uncontrollable oxidation impurities (I) and (II) which are easy to generate in the industrial production of duloxetine L-tartrate;

2) the structure of the oxidized impurities is prepared and verified, and reference or contrast is provided for quantitative and qualitative analysis of duloxetine L-tartrate impurity detection;

3) the method controls the generation of impurities (I) and (II), ensures the purity of the duloxetine and the L-tartrate thereof, improves the product quality, and has very important guiding significance on the medication safety of the duloxetine.

In conclusion, the invention provides refractory oxidized impurities (I) and (II) of duloxetine L-tartrate, a preparation method and a quality control method thereof. The technical problems that the impurities cannot be separated and obtained in the prior art, so that the impurities cannot be subjected to structure identification and quality control are solved. The quality stability and the medication safety of the duloxetine L-tartrate are ensured.

Drawings

FIG. 1 is a high resolution mass spectrum of duloxetine L-tartrate impurity (II) obtained in example 1;

FIG. 2 shows the preparation of duloxetine L-tartrate impurity (II) from example 1¹HNMR nuclear magnetic spectrum;

FIG. 3 shows the preparation of duloxetine L-tartrate impurity (II) from example 1¹³A CNMR nuclear magnetic spectrum;

FIG. 4 is an HPLC plot of duloxetine L-tartrate impurity (II) prepared in example 1;

FIG. 5 is an HPLC plot of the product of test 1 of comparative example 1 having an RRT1.09 impurity level of 0.95%;

FIG. 6 is an HPLC chart showing the content of duloxetine of 99.71% and the content of RRT1.09 impurity of 0.08% obtained in comparative example 3.

Detailed Description

The invention is further illustrated with reference to specific examples, which are not intended to limit the invention in any way.

The intermediate (2-I) used in the invention is prepared into a crude product by referring to a preparation method in a patent CN101232890, and then the crude product is recrystallized and purified by methanol, and the purification yield is about 92%.

Other compounds or reagents were prepared by conventional methods or were commercially available from the company.

"boronic acid protecting group" refers to a moiety that blocks or protects the function of a boronic acid when subjected to a reaction involving other functional sites of a compound. Typically, the boronic acid hydroxyl group is protected as a boronic ester derived from an alcohol, such as (+) -pinanediol, pinacol, 1, 2-dicyclohexyl-ethylene glycol, 1, 2-ethylene glycol, 2-diethanolamine, 1, 3-propanediol, 2, 3-butanediol, diisopropyl tartrate, 1, 4-butanediol, diisopropyl glycol, (S, S) -5, 6-decanediol, 1, 2-triphenyl-1, 2-ethanediol, (2R, 3R) -1, 4-dimethoxy-1, 1, 4, 4-tetraphenyl-2, 3-butanediol, methanol, ethanol, isopropanol, catechol, 1-butanol, or the like. Those skilled in the art will understandAlcohols having only a single hydroxyl group, such as methanol, form diesters having the formula-B (OR)2, where R is the organic moiety from the alcohol (e.g., -B (OMe))₂). In contrast, diols such as pinacol are formed with-B (OR)₂The cyclic boronic acid diester of (a), wherein the organic moiety (e.g. -C (Me))₂-C(Me)₂-) connects two oxygens.

-Cbz: a benzyloxycarbonyl group;

-PMB: p-methoxybenzyl;

-Bn: a benzyl group.