阅读说明：本技术 一种n,n-二烃基酰胺羧酸化合物及其制备方法和应用 (N, N-dialkyl amide carboxylic acid compound and preparation method and application thereof ) 是由 王艳良 肖文涛 吴玉远 林锦池 于 2021-06-24 设计创作，主要内容包括：本发明提出了一种N,N-二烃基酰胺羧酸化合物及其制备方法和应用。所述的N,N-二烃基酰胺羧酸化合物可作为萃取剂用于从低浓度稀土原料中富集稀土元素,从混合稀土原料中分离和提纯钇元素,从混合稀土原料中分离铝、铁、放射性钍、放射性铀和锕等元素。该化合物合成简单,成本低廉,作为萃取剂化学稳定性好,能够耐受强酸和强碱而不发生分解。(The invention provides an N, N-dialkyl amide carboxylic acid compound and a preparation method and application thereof. The N, N-dialkyl amide carboxylic acid compound can be used as an extracting agent for enriching rare earth elements from low-concentration rare earth raw materials, separating and purifying yttrium elements from mixed rare earth raw materials, and separating elements such as aluminum, iron, radioactive thorium, radioactive uranium, actinium and the like from the mixed rare earth raw materials. The compound has simple synthesis, low cost and good chemical stability as an extractant, and can tolerate strong acid and strong alkali without decomposition.)

1. An N, N-dihydrocarbylaminocarboxylic acid compound, wherein the N, N-dihydrocarbylaminocarboxylic acid compound has the structure shown in formula I:

wherein R is₁And R₂Independently is a linear or branched, substituted or unsubstituted, unsaturated hydrocarbon group of C4 and above;

R₃is a linear or branched, substituted or unsubstituted, saturated or unsaturated hydrocarbon group;

n is a natural number of 1 to 10, preferably 1 to 6.

2. The N, N-dihydrocarbylamide carboxylic acid compound of claim 1, wherein R is₁And R₂Independently, the alkyl group is a linear or branched chain unsubstituted unsaturated alkyl group with more than C4, preferably a linear or branched chain unsubstituted unsaturated alkyl group with C4-C20, more preferably a linear or branched chain unsubstituted alkenyl group with C4-C20.

3. The N, N-dihydrocarbylamide carboxylic acid compound of claim 1 or 2, wherein R is₁And R₂Independently any one of the following groups, wherein,represents the position of attachment of the group:

4. the N, N-dihydrocarbylamide carboxylic acid compound of any of claims 1-3, wherein R is₃Selected from linear or branched, substituted or unsubstituted, saturated or unsaturated hydrocarbon groups of above C4, preferably linear or branched, unsubstituted unsaturated hydrocarbon groups of C4-C30, more preferably linear or branched, unsubstituted alkenyl groups of C4-C18.

5. The N, N-dihydrocarbylamide carboxylic acid compound of any of claims 1-4, wherein R is₃Is any one of the following groups, wherein,represents the position of attachment of the group:

6. the method for producing an N, N-dihydrocarbylaminocarboxylic acid compound according to any one of claims 1 to 5, wherein the method for producing an N, N-dihydrocarbylaminocarboxylic acid compound is:

mixing N, N-dihydrocarbyl secondary amine shown in a formula II and dianhydride compound shown in a formula III for reaction to obtain N, N-dihydrocarbyl amide carboxylic acid compound shown in a formula I, wherein the reaction formula is as follows:

wherein R is₁、R₂、R₃A group as defined in any one of claims 1 to 5, n is a natural number of 1 to 10;

or mixing N, N-dihydrocarbyl secondary amine shown in a formula II and carboxylic acid mono-chloride compound shown in a formula IV for reaction to obtain N, N-dihydrocarbyl amide carboxylic acid shown in a formula I, wherein the reaction formula is as follows:

wherein R is₁、R₂、R₃A group as defined in any one of claims 1 to 5, n being a natural number of 1 to 10.

7. The method for producing an N, N-dihydrocarbylamide carboxylic acid compound according to claim 6, wherein the molar ratio of the N, N-dihydrocarbylamide carboxylic acid compound of the formula II to the dianhydride compound of the formula III is 1 (0.8 to 1.2);

preferably, the molar ratio of the N, N-dihydrocarbyl secondary amine shown in the formula II to the carboxylic acid monoacid chloride compound shown in the formula IV is 1 (0.8-1.2).

8. The method for producing an N, N-dihydrocarbylaminocarboxylic acid compound according to claim 6 or 7, wherein the temperature of the mixing reaction of the secondary N, N-dihydrocarbylamide carboxylic acid compound of formula II with the dianhydride compound of formula III is from 0 to 125 ℃ and the time of the mixing reaction is from 0.5 to 4 hours;

preferably, the temperature for mixing and reacting the N, N-dihydrocarbyl secondary amine shown in the formula II and the carboxylic acid monoacid chloride compound shown in the formula IV is 0-125 ℃, and the mixing and reacting time is 0.5-4 h.

9. The method for producing an N, N-dihydrocarbylaminocarboxylic acid compound according to any one of claims 6 to 8, wherein the mixing reaction of the N, N-dihydrocarbylamide carboxylic acid compound of formula II and the dianhydride compound of formula III is carried out in the absence of a solvent; or in a solvent;

preferably, the mixed reaction of the N, N-dihydrocarbyl secondary amine shown in the formula II and the carboxylic acid monoacyl chloride compound shown in the formula IV is carried out in the absence of a solvent; or in a solvent;

preferably, the solvent is an inert solvent selected from any one or a combination of at least two of hexane, dichloromethane, petroleum ether, toluene, xylene or kerosene.

10. Use of an N, N-dihydrocarbylaminocarboxylic acid compound according to any one of claims 1 to 5, for the preparation of an extractant for separating rare earth elements.

Technical Field

The invention relates to the technical field of organic compound synthesis, in particular to an N, N-dialkyl amide carboxylic acid compound and a preparation method and application thereof.

Background

The rare earth elements refer to 15 lanthanide elements with atomic numbers of 57-71 in the periodic table, and 17 metal elements including No. 21 scandium and No. 39 yttrium with similar chemical properties. The rare earth element has unique magnetic, optical and electrical properties, is known as 'industrial vitamin', is widely applied to the fields of metallurgy, petrochemical industry, glass ceramics, energy materials, military industry and the like, and is an important fundamental raw material for the development of human society.

At present, the exploitation of rare earth ore in nature firstly needs to use a leaching agent to leach rare earth ions to obtain a rare earth leaching solution, and then the rare earth ions are extracted and separated one by one in a solvent extraction mode. The development of an extractant is the most central technology in the solvent extraction process, multiple factors such as extraction selectivity, extraction rate, extraction capacity, stability, solubility, back extraction performance, safety, synthesis method and source of a compound need to be considered in the rare earth metal extractant for industrial application, the excellent extractant can be called one of ten thousand, and the good extractant can simplify the production process, improve the separation efficiency, reduce the production cost and reduce the pollution emission.

Commercially available extractant products known in the art are mainly classified into organic phosphine extractants, carboxylic acid extractants, and amine extractants, typical organic phosphine extractants include mono (2-ethylhexyl) 2-ethylhexyl phosphonate (P507), di (2-ethylhexyl) phosphonic acid (P204), di (2,4, 4-trimethylpentyl) phosphinic acid (C272), tributyl phosphonate (TBP), etc., amine extractants include tri-N-octylamine (N235), secondary primary amine (N1923), methyltrioctylammonium chloride (N263), etc., and carboxylic acid extractants include naphthenic acid, neodecanoic acid, secondary octylphenoxyacetic acid (CA-12), etc.

The commercially available extractant still has some defects, for example, P507 is the one most widely used in the rare earth separation industry, but the separation coefficient of the extractant for adjacent rare earth elements is low, such as the separation coefficient of praseodymium-neodymium is only 1.4, which makes the praseodymium-neodymium element difficult to separate. Naphthenic acid is mainly used for separating and purifying yttrium oxide, but the naphthenic acid is a byproduct of petrochemical industry, has complex components, can extract rare earth under the condition of higher pH, and has easily changed components after long-term use, thereby reducing the concentration of an organic phase and influencing the stability of a separation process. CA-12 extractant has been tried to replace naphthenic acid, which can effectively separate yttrium from all lanthanides in rare earth element extraction separation process and overcome the problem of reduced organic phase concentration when the naphthenic acid is used for extracting and separating yttrium, but the separation coefficient of heavy rare earth and yttrium in the extraction system is low, which causes the heavy rare earth element and yttrium to be difficult to separate, thus more stages of extraction tanks are required to be designed to achieve separation effect.

The amido carboxylic acid is a novel extractant containing N and O ligands, has certain selectivity for extracting transition metal ions, has stable chemical structure and fast extraction kinetics, and is an extractant with wide application prospect.

The prior art discloses various methods for preparing amide carboxylic acid compounds, for example, CN109824532A discloses a new process for synthesizing N, N' -tetraoctyl-3-oxoglutaramide (TODGA). The method comprises the following steps: (1) diglycolic acid with SOCl₂Reacting to generate diglycoyl chloride, and reacting with amine to generate partial TODGA; (2) removing water-soluble components from the by-product, and separating to obtain mono-oxa-amide carboxylic acid; (3) the TODGA is partially regenerated by reacting the mono-oxa-amide carboxylic acid with an amine. The process combines the characteristics of the existing process, and has high yield.

CN104529861A provides a method for synthesizing imide-based modified low molecular weight novolac resin, which comprises the following steps: in N, N-dimethylformamide or a mixed solvent mainly containing N, N-dimethylformamide, p-aminophenol reacts with anhydride of dicarboxylic acid to obtain an amide carboxylic acid phenolic compound, and then the amide carboxylic acid phenolic compound and 2, 6-dihydroxymethyl-p-cresol undergo polycondensation reaction and dehydration ring-closing reaction under the catalysis of an acidic catalyst such as oxalic acid to obtain the imide group modified low molecular weight linear phenolic resin.

CN106892835A discloses a bisdiglycolamide ligand, a preparation method thereof and a lanthanide/actinide separation and extraction system containing the bisdiglycolamide ligand, wherein the extraction system is formed by mixing an organic phase and a water phase in equal volumes, and the organic phase contains N, N, N ', N ', N ' -hexa-N-octyl-nitrilotriacetamide with the molar concentration of 0.1-0.7 mol/L as an extractant; the N, N, N ', N ', N ' -hexa-N-octyl-nitrilotriacetic amide in the extraction system has a unique triangular structure without N heterocyclic rings, so that the irradiation resistance stability of the extraction system can be greatly improved, secondary pollutants cannot be generated, and the environment protection is facilitated; the water-soluble bisdiglycolamide ligand is used as a masking agent in the extraction system, has the characteristic of being more prone to complexing with lanthanide, and can effectively mask the lanthanide in a water phase to realize selective separation of actinide and lanthanide.

It is apparent from the disclosure that the prior art, while providing a method for producing an amide carboxylic acid, does not provide an amide carboxylic acid compound and an extraction separation method thereof capable of more efficiently separating rare earth elements. In order to more effectively separate rare earth elements, it is required to develop a novel extractant having a higher separation coefficient than the prior art and capable of overcoming the disadvantages of the prior art, and an extraction separation method using the same.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide an N, N-dialkyl amide carboxylic acid compound and a preparation method and application thereof. The N, N-dialkyl amide carboxylic acid compound can be used as an extracting agent for separating and purifying selected rare earth elements from mixed rare earth material liquid, and particularly extracting and separating yttrium elements from a rare earth element mixture.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides an N, N-dihydrocarbylamide carboxylic acid compound having the structure shown in formula I below:

wherein R is₁And R₂A linear or branched, substituted or unsubstituted, unsaturated hydrocarbon group independently of C4 or more (for example, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C22, C24, C26, C28, C30, C35, C40, etc.);

R₃is a linear or branched, substituted or unsubstituted, saturated or unsaturated hydrocarbon group;

n is a natural number of 1 to 10 (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.), and preferably a natural number of 1 to 6.

The invention provides an amide carboxylic acid compound with a structure shown in formula I as a carboxylic acid type extractant for separating rare earth metals and an extraction separation method thereof, and the compound is not reported as a rare earth metal extractant. The compound as a metal extractant has a high separation coefficient for rare earth elements, particularly has high efficiency for separating heavy rare earth and yttrium elements, and can overcome the defects existing in the process of separating yttrium from naphthenic acid.

In the present invention, the hydrocarbon group is any one of a substituted alkyl group, a substituted alkenyl group and a substituted alkynyl group, and the substituents of the alkyl group, the alkenyl group and the alkynyl group are each independently selected from any one or a combination of at least two of halogen, hydroxyl group, carboxyl group, acyl group, ester group, ether group, alkoxy group, phenyl group, phenoxy group, amino group, amide group, nitro group, cyano group, mercapto group, sulfonyl group, thiol group, imino group, sulfonyl group and sulfanyl group; preferably, the substituent is halogen.

Preferably, said R is₁And R₂Independently a linear or branched, unsubstituted unsaturated hydrocarbon group (linear or branched and unsubstituted alkenyl or alkynyl group) of C4 or more, for example (C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C22, C24, C26, C28, C30, C35, C40, etc.), preferably a linear or branched, unsubstituted unsaturated hydrocarbon group of C4 to C20, more preferably a linear or branched, unsubstituted alkenyl group of C4 to C20.

Preferably, said R is₁And R₂Independently a linear or branched alkenyl or alkynyl group (linear or branched and unsubstituted alkenyl or alkynyl group) of C4 or more, more preferably a linear or branched and unsubstituted alkenyl group of C4 or more.

Preferably, said R is₁And R₂Independently any one of the following groups, wherein,represents the position of attachment of the group:

preferably, said R is₃A linear or branched, substituted or unsubstituted, saturated or unsaturated hydrocarbon group selected from C4 and more (for example, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C30, C40, etc.), preferably a linear or branched, unsubstituted unsaturated hydrocarbon group of C4 to C30, more preferably a linear or branched, unsubstituted unsaturated hydrocarbon group of C4 to C18.

Preferably, said R is₃The alkyl group is selected from a linear or branched unsaturated unsubstituted alkyl group having at least C4 (for example, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, etc.), preferably a linear or branched, unsaturated, unsubstituted alkyl group having at least C4, specifically a linear or unsubstituted alkenyl group, and further a linear alkenyl group having C4-C18.

Preferably, said R is₃Is a linear alkenyl of C10-C18.

Preferably, said R is₃Is any one of the following groups, wherein,represents the linking site of the group:

in a second aspect, the present invention provides a method for preparing an N, N-dihydrocarbylamide carboxylic acid compound as described in the first aspect, the method comprising:

mixing N, N-dihydrocarbyl secondary amine shown in a formula II and dianhydride compound shown in a formula III for reaction to obtain N, N-dihydrocarbyl amide carboxylic acid compound shown in a formula I, wherein the reaction formula is as follows:

wherein R is₁、R₂、R₃Is a group as defined in the first aspect, n is a natural number of 1 to 10;

or mixing N, N-dihydrocarbyl secondary amine shown in formula II and acyl chloride anhydride compound shown in formula IV for reaction to obtain N, N-dihydrocarbyl amide carboxylic acid compound shown in formula I, wherein the reaction formula is as follows:

wherein R is₁、R₂、R₃N is a natural number of 1 to 10.

Preferably, the molar ratio of the N, N-dihydrocarbyl secondary amine of formula II to the dianhydride compound of formula III is 1 (0.8-1.2), and may be, for example, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, etc.

Preferably, the molar ratio of the N, N-dihydrocarbyl secondary amine of formula II to the acid chloride anhydride compound of formula IV is 1 (0.8-1.2), and may be, for example, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, etc.

Preferably, the temperature of the mixing reaction of the N, N-dihydrocarbyl secondary amine of formula II and the dianhydride compound of formula III is 0-125 deg.C, such as 0 deg.C, 5 deg.C, 10 deg.C, 15 deg.C, 20 deg.C, 25 deg.C, 30 deg.C, 35 deg.C, 40 deg.C, 50 deg.C, 60 deg.C, 70 deg.C, 80 deg.C, 90 deg.C, 100 deg.C, 105 deg.C, 110 deg.C, 115 deg.C, 120 deg.C, 125 deg.C, and the mixing reaction time is 0.5-4h, such as 0.5h, 0.6h, 0.8h, 1h, 1.2h, 1.4h, 1.6h, 1.8h, 2h, 2.2h, 2.4h, 2.6h, 2.8h, 3h, 3.2h, 3.4h, 3.6h, 3.8h, 4h, etc.

Preferably, the temperature of the mixing reaction of the N, N-dihydrocarbyl secondary amine of formula II and the acid chloride anhydride compound of formula IV is 0 to 125 ℃, for example, 0 ℃, 5 ℃, 10 ℃, 15 ℃, 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃, 50 ℃, 60 ℃, 70 ℃, 80 ℃, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃, 125 ℃ and the like, and the mixing reaction time is 0.5 to 4 hours, for example, 0.5 hour, 0.6 hour, 0.8 hour, 1 hour, 1.2 hour, 1.4 hour, 1.6 hour, 1.8 hour, 2 hour, 2.2 hour, 2.4 hour, 2.6 hour, 2.8 hour, 3 hour, 3.2 hour, 3.4 hour, 3.6 hour, 3.8 hour, 4 hour and the like.

Preferably, the mixing reaction of the N, N-dihydrocarbyl secondary amine shown in the formula II and the dianhydride compound shown in the formula III is carried out in the absence of a solvent; or in a solvent.

Preferably, the mixed reaction of the N, N-dihydrocarbyl secondary amine shown in the formula II and the acyl chloride anhydride compound shown in the formula IV is carried out in the absence of a solvent; or in a solvent.

In the present invention, it is worth mentioning that the reaction can also be carried out under the solvent-free condition, and the compound with the structure shown in formula II and the compound with the structure shown in formula III are directly mixed and reacted.

Preferably, the solvent is an inert solvent selected from any one or a combination of at least two of hexane, dichloromethane, petroleum ether, toluene, xylene or kerosene.

In a third aspect, the present invention provides the use of an N, N-dihydrocarbylamide carboxylic acid compound as described in the first aspect, in the preparation of an extractant for separating rare earth elements.

Preferably, the separation of the rare earth element is specifically extraction separation of yttrium element from a rare earth element mixture.

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

(1) the amide carboxylic acid provided by the invention can be used for enriching rare earth elements from low-concentration rare earth raw materials, separating and purifying yttrium elements from mixed rare earth raw materials, removing elements such as aluminum, iron, radioactive thorium, radioactive uranium, actinium and the like from the mixed rare earth raw materials, and other fields.

(2) The amide carboxylic acid provided by the invention has good chemical stability, and can tolerate strong acid and strong alkali without decomposition.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the specific embodiments are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

This example provides a compound I-1 of formula I, wherein the formula of compound I-1 is shown below:

the synthetic route of compound I-1 is shown below:

(1) dissolving N, N-dihydrocarbyldiamine represented by formula II-1 (12.5g, 0.1mol) in toluene (20mL) to obtain solution one; dissolving a dianhydride compound shown in formula III-1 (28.2g, 0.1mol) in toluene (30mL) to obtain a solution II;

(2) adding the solution I into the solution II, stirring the solution, raising the temperature to 80 ℃, maintaining the reaction temperature for 2 hours, and after the reaction is finished, concentrating in vacuum to remove toluene to obtain the compound I-1.

The solvent-free synthesis method comprises the following steps:

directly mixing N, N-dihydrocarbyl secondary amine (12.5g, 0.1mol) shown in formula II-1 with dianhydride compound (28.2g, 0.1mol) shown in formula III-1 to form a mixed solution, stirring the mixed solution, raising the temperature to 80 ℃, maintaining the temperature for 2 hours, and obtaining compound I-1 after the reaction is finished.

Or, mixing N, N-dihydrocarbyl secondary amine shown in formula II-1 and carboxylic acid monoacid chloride compound shown in formula III-1a for reaction, wherein the reaction formula is as follows:

the synthesis method comprises the following steps: directly mixing N, N-dihydrocarbyl secondary amine (24.2g, 0.10mol) shown in formula II-1 with carboxylic acid monoacid chloride compound (31.7g, 0.10mol) shown in formula III-1a to form a mixed solution, stirring the mixed solution, raising the temperature to 80 ℃, maintaining the temperature for 2 hours at the reaction temperature, and obtaining compound I-1 after the reaction is finished.

The invention carries out nuclear magnetic resonance analysis on the compound I-1:

¹H NMR(500MHz,CDCl₃),δ12.01(1H),7.11(1H),7.05(1H),5.66(1H),5.56(1H),5.13(1H),4.98(1H),3.02(1H),2.33(2H),2.02(4H),1.94(2H),1.84(2H),1.33(2H),1.30(4H),1.29(2H),1.26(8H),0.88(3H),0.78(6H)。

¹³C NMR(500MHz,CDCl₃),δ178.4,165.7,128.9,128.3,125.5(2C),99.8(2C),37.6,33.0,31.9,29.9,29.7,29.7,29.6,29.6,29.3,27.9,27.3,24.0(2C),22.7,14.1,14.0(2C)。

example 2

The synthetic route of compound I-2 is shown below:

(1) dissolving N, N-dihydrocarbyldiamine represented by formula II-2 (15.3g, 0.1mol) in toluene (20mL) to obtain a solution I; dissolving a dianhydride compound shown in formula III-2 (28.2g, 0.1mol) in toluene (30mL) to obtain a solution II;

(2) adding the solution I into the solution II, stirring the solution, raising the temperature to 85 ℃, maintaining the reaction temperature for 2 hours, and after the reaction is finished, concentrating in vacuum to remove toluene to obtain the compound I-2.

The invention carries out nuclear magnetic resonance analysis on the compound I-2:

¹H NMR(500MHz,CDCl₃),δ12.01(1H),7.11(1H),7.05(1H),5.66(2H),5.13(1H),4.98(1H),3.02(1H),2.33(2H),2.16(4H),1.94(2H),1.84(2H),1.46(4H),1.33(2H),1.30(4H),1.29(2H),1.26(8H),0.95(6H),0.88(3H)。

¹³C NMR(500MHz,CDCl₃),δ178.4,165.7,128.9,128.3,124.9(2C),100.5(2C),37.6,33.0,31.9,29.9,29.7(2C),29.6(2C),29.3,27.9,27.4(2C),27.3,23.0(2C),22.7,14.2(2C),14.1。

example 3

The synthetic route of compound I-3 is shown below:

(1) dissolving N, N-dihydrocarbyldiamine represented by formula II-3 (15.3g, 0.1mol) in toluene (20mL) to obtain solution one; dissolving a dianhydride compound shown in formula III-3 (28.2g, 0.1mol) in toluene (30mL) to obtain a solution II;

(2) adding the solution I into the solution II, stirring the solution, raising the temperature to 80 ℃, maintaining the temperature for 1.5h, and after the reaction is finished, concentrating in vacuum to remove toluene to obtain the compound I-3.

The invention carries out nuclear magnetic resonance analysis on the compound I-3:

¹H NMR(500MHz,CDCl₃),δ12.01(1H)，5.66(2H),5.32(2H),3.87(4H),3.02(1H),2.33(2H),2.05(6H),1.94(2H),1.84(2H),1.79(6H),1.33(2H),1.30(4H),1.29(2H),1.26(8H),0.88(3H)。

¹³C NMR(500MHz，CDCl₃),δ178.4,171.4,136.3(2C),128.9,128.3,122.4(2C),56.5(2C),37.6,33.0,31.9,29.9,29.7,29.7,29.6,29.6,29.3,27.7,27.3,22.7,14.5(2C),14.1,12.4(2C)。

example 4

The synthetic route of compound I-4 is shown below:

(1) dissolving N, N-dihydrocarbyldiamine represented by formula II-4 (18.1g, 0.1mol) in toluene (20mL) to obtain solution one; dissolving a dianhydride compound shown in formula III-4 (28.2g, 0.1mol) in toluene (30mL) to obtain a solution II;

(2) adding the solution I into the solution II, stirring the solution, raising the temperature to 90 ℃, maintaining the temperature for 2 hours, and after the reaction is finished, concentrating in vacuum to remove the toluene to obtain the compound I-4.

The invention carries out nuclear magnetic resonance analysis on the compound I-4:

¹H NMR(500MHz，CDCl₃),δ12.01(1H),7.11(2H),5.66(1H),5.56(1H),5.13(2H),3.02(1H),2.33(2H),2.16(4H),1.94(2H),1.84(2H),1.46(4H),1.38(4H),1.33(2H),1.30(4H),1.29(4H),1.28(2H),1.26(8H),0.93(6H),0.88(3H)。

¹³C NMR(500MHz,CDCl₃),δ178.4,165.7,128.9,128.3,124.9(2C),103.1(2C),37.6,31.8(2C),33.0,31.9,29.9,29.7,29.7,29.6,29.6,29.3，27.9,27.3,22.8(2C),22.7,18.9(2C),14.2(2C),14.1。

example 5

This example provides a compound I-5 of formula I, wherein the formula of compound I-5 is shown below:

the synthetic route of compound I-5 is shown below:

(1) dissolving N, N-dihydrocarbyldiamine represented by the formula II-5 (29.3g, 0.1mol) in toluene (20mL) to obtain a solution I; dissolving a dianhydride compound shown in formula III-5 (28.2g, 0.1mol) in toluene (30mL) to obtain a solution II;

(2) adding the solution I into the solution II, stirring the solution, raising the temperature to 80 ℃, maintaining the reaction temperature for 3 hours, and after the reaction is finished, concentrating in vacuum to remove toluene to obtain the compound I-5.

The invention carries out nuclear magnetic resonance analysis on the compound I-5:

¹H NMR(500MHz，CDCl₃),δ12.01(1H)，7.11(1H)，7.05(1H)，5.66(1H)，5.56(1H)，5.13(1H)，4.98(1H)，3.02(1H)，2.33(2H),2.16(4H),1.94(2H),1.84(2H),1.33(6H),1.30(8H),1.29(6H),1.26(20H),0.88(9H)。

¹³C NMR(500MHz,CDCl₃),δ178.4,165.7,128.9,128.3,124.8(2C),103.1(2C),37.6,33.0,31.9,31.9(2C),29.9,29.7,29.7,29.7(4C),29.6,29.6,29.6(2C),29.3,29.3(2C),27.9,27.3,22.7,22.7(2C),19.2(2C),14.1,14.1(2C)。

example 6

This example provides a compound I-6 of formula I, wherein the formula of compound I-6 is shown below:

the synthetic route of compound I-6 is shown below:

(1) dissolving N, N-dihydrocarbyldiamine represented by the formula II-6 (12.1g, 0.1mol) in toluene (20mL) to obtain a solution I; dissolving a dianhydride compound shown in formula III-6 (28.2g, 0.1mol) in toluene (30mL) to obtain a solution II;

(2) adding the solution I into the solution II, stirring the solution, raising the temperature to 85 ℃, maintaining the reaction temperature for 3 hours, and after the reaction is finished, concentrating in vacuum to remove toluene to obtain the compound I-6.

The invention carries out nuclear magnetic resonance analysis on the compound I-6:

¹H NMR(500MHz，CDCl₃),δ12.01(1H),5.66(1H),5.56(1H),3.02(1H),2.33(2H),2.23(4H),1.94(2H),1.84(2H),1.33(2H),1.30(4H),1.29(2H),1.26(8H),1.14(6H),0.88(3H)。

¹³C NMR(500MHz，CDCl₃),δ178.4,174.8,128.9,128.3,85.8(2C),83.0(2C),35.0,33.0,31.9,29.9,29.7(2C),29.6(2C),29.3,27.3,25.9,22.7,14.1,13.6(2C),9.1(2C)。

example 7

This example provides a compound I-7 of formula I, wherein the formula of compound I-7 is shown below:

the synthetic route of compound I-7 is shown below:

(1) dissolving N, N-dialkenylsecondary amine represented by the formula II-7 (12.6g, 0.1mol) in toluene (20mL) to obtain a solution I; dissolving a dianhydride compound shown in the formula III-7 (15.6g, 0.1mol) in toluene (30mL) to obtain a solution II;

(2) adding the solution I into the solution II, stirring the solution, raising the temperature to 85 ℃, maintaining the reaction temperature for 5 hours, and after the reaction is finished, concentrating in vacuum to remove the toluene to obtain the compound I-7.

The invention carries out nuclear magnetic resonance analysis on the compound I-7:

¹H NMR(500MHz,CDCl₃),δ12.01(1H),7.11(1H),7.05(1H),5.13(1H),4.98(1H),2.33(2H),2.27(1H),2.02(4H),1.78(2H),1.62(1H),1.43(2H),0.91(6H),0.78(6H)。

¹³C NMR(500MHz,CDCl₃),δ178.4,169.5,125.5(2C),99.8(2C),41.4,39.2,30.4,26.3,24.9,24.0,22.8(2C),18.0,14.0(2C)。

example 8

This example provides a compound I-8 of formula I, wherein the formula of compound I-8 is shown below:

the synthetic route of compound I-8 is shown below:

(1) dissolving N, N-dibutenylsecondary amine represented by the formula II-8 (12.6g, 0.1mol) in toluene (20mL) to obtain a solution I; dissolving a dianhydride compound shown in the formula III-8 (31.0g, 0.1mol) in toluene (30mL) to obtain a solution II;

(2) adding the solution I into the solution II, stirring the solution, raising the temperature to 80 ℃, maintaining the reaction temperature for 2 hours, and after the reaction is finished, concentrating in vacuum to remove toluene to obtain the compound I-8.

The invention carries out nuclear magnetic resonance analysis on the compound I-8:

¹H NMR(500MHz，CDCl₃),δ11.80(1H),7.11(2H),5.66(1H),5.56(1H),5.13(2H),3.02(1H),2.21(2H),2.02(4H),1.94(2H),1.55(2H),1.54(2H),1.33(2H),1.30(4H),1.29(2H),1.26(8H),1.25(2H),0.88(3H),0.78(6H)。

¹³C NMR(500MHz，CDCl₃),δ178.4,165.7,130.9,128.8,125.5(2C),99.8(2C),38.2,34.7,34.0,31.9,29.9,29.7,29.7,29.6,29.6,29.3,27.3,25.9,24.4,22.7,18.0(2C),14.1,14.0(2C)。

example 9

This example provides a compound I-9 of formula I, wherein the formula of compound I-9 is shown below:

the synthetic route of compound I-9 is shown below:

(1) dissolving N, N-dihydrocarbyldiamine represented by the formula II-9 (54.1g, 0.1mol) in toluene (20mL) to obtain a solution I; dissolving a dianhydride compound shown in the formula III-9 (19.6g, 0.1mol) in toluene (30mL) to obtain a solution II;

(2) adding the solution I into the solution II, stirring the solution, raising the temperature to 80 ℃, maintaining the reaction temperature for 2 hours, and after the reaction is finished, concentrating in vacuum to remove toluene to obtain the compound I-9.

The invention carries out nuclear magnetic resonance analysis on the compound I-9:

¹H NMR(500MHz,CDCl₃),δ11.87(1H),5.94(1H),5.25(1H),5.21(1H),3.02(1H),2.46(4H),2.21(2H),1.55(2H),1.54(2H),1.44(4H),1.33(2H),1.29(4H),1.26(52H),1.25(4H),0.88(6H)。

¹³C NMR(500MHz,CDCl₃),δ178.4,174.8,140.8,114.6,83.3(2C),81.9(2C),41.8,34.0,32.7,31.9(2C),29.9,29.6(18C),29.3(2C),29.0,29.0,28.7(4C),28.4(2C),24.7,22.7(2C),15.6(2C),14.1(2C)。

example 10

This example provides a compound I-10 of formula I, wherein the formula of compound I-10 is shown below:

the synthetic route of compound I-10 is shown below:

(1) dissolving N, N-dihydrocarbyldiamine represented by formula II-10 (34.9g, 0.1mol) in toluene (20mL) to give solution one; dissolving a dianhydride compound shown in formula III-10 (26.6g, 0.1mol) in toluene (30mL) to obtain a solution II;

(2) adding the solution I into the solution II, stirring the solution, raising the temperature to 80 ℃, maintaining the reaction temperature for 2 hours, and after the reaction is finished, concentrating in vacuum to remove toluene to obtain the compound I-10.

The invention carries out nuclear magnetic resonance analysis on the compound I-10:

¹H NMR(500MHz,CDCl₃),δ11.87(1H),7.11(2H),5.72(1H),5.57(1H),5.13(2H),3.02(1H),2.21(2H),2.16(4H),1.94(2H),1.55(2H),1.54(2H),1.38(2H),1.33(6H),1.30(10H),1.29(6H),1.26(16H),1.25(4H),0.93(3H),0.88(6H)。

¹³C NMR(500MHz,CDCl₃),δ178.4,165.7,130.9,128.8,124.8(2C),103.1(2C),44.2,35.0,34.0,33.0,32.1,31.9(2C),29.9,29.7(4C),29.6(6C),29.3(2C),29.3,29.3,29.0,25.2,24.7,22.8,22.7(2C),19.2,14.2,14.1(2C)。

comparative example 1

This comparative example provides a compound I-d1, the compound I-d1 having the formula:

the synthetic route of compound I-d1 is shown below:

(1) dissolving a N, N-dihydrocarbyldiamine of formula II-d1 (6.7g, 0.1mol) in toluene (20mL) to give a solution one; dissolving a dianhydride compound shown in formula III-d1 (28.2g, 0.1mol) in toluene (30mL) to obtain a solution II;

(2) adding the solution I into the solution II, stirring the solution, raising the temperature to 85 ℃, maintaining the temperature for 2.5h, and after the reaction is finished, concentrating in vacuum to remove toluene to obtain the compound I-d 1.

The nuclear magnetic resonance analysis of the compound I-d1 is carried out by the invention:

¹H NMR(500MHz,CDCl₃),δ12.01(1H),7.33(2H),6.10(2H),5.66(1H),5.56(1H),4.68(2H),3.02(1H),2.33(2H),1.94(2H),1.84(2H),1.33(2H),1.30(4H),1.29(2H),1.26(8H),0.88(3H)。

¹³C NMR(500MHz,CDCl₃),δ178.4,165.7,128.9,128.3,126.3(2C),101.6(2C),37.6,33.0,31.9,29.9,29.7,29.7,29.6,29.6,29.3,27.9,27.3,22.7,14.1。

comparative example 2

This comparative example provides a compound I-d2, the compound I-d2 having the formula:

the synthetic route of compound I-d2 is shown below:

(1) dissolving a N, N-dihydrocarbyldiamine of formula II-d2 (15.7g, 0.1mol) in toluene (20mL) to give a solution one; dissolving a dianhydride compound shown in formula III-d2 (28.2g, 0.1mol) in toluene (30mL) to obtain a solution II;

(2) adding the first solution into the second solution, stirring the solution, raising the temperature to 80 ℃, maintaining the reaction temperature for 2 hours, and after the reaction is finished, concentrating in vacuum to remove toluene to obtain the compound I-d 2.

The nuclear magnetic resonance analysis of the compound I-d2 is carried out by the invention:

¹H NMR(500MHz，CDCl₃),δ12.01(1H),5.66(1H),5.56(1H),3.60(2H),3.02(1H),2.33(2H),1.94(2H),1.84(2H),1.47(4H),1.33(2H),1.31(4H),1.30(4H),1.29(2H),1.26(8H),1.26(6H),0.89(6H),0.88(3H)。

¹³C NMR(500MHz，CDCl₃),δ178.4,170.2,128.9,128.3,58.9(2C),38.0,37.7(2C),33.0,31.9,29.9,29.7,29.7,29.6,29.6,29.3,27.7,27.3,22.7,20.2(2C),18.9(2C),14.1(2C),14.0。

comparative example 3

This comparative example provides a compound I-d3, the compound I-d3 having the formula:

the synthetic route of compound I-d3 is shown below:

(1) dissolving a N, N-dihydrocarbyldiamine of formula II-d3 (12.9g, 0.1mol) in toluene (20mL) to give solution one; dissolving a dianhydride compound shown in formula III-d3 (28.1g, 0.1mol) in toluene (30mL) to obtain a solution II;

(2) adding the first solution into the second solution, stirring the solution, raising the temperature to 80 ℃, maintaining the reaction temperature for 2 hours, and after the reaction is finished, concentrating in vacuum to remove toluene to obtain the compound I-d 3.

The nuclear magnetic resonance analysis of the compound I-d3 is carried out by the invention:

¹H NMR(500MHz，CDCl₃),δ12.01(1H),5.66(1H),5.56(1H),3.18(4H),3.02(1H),2.33(2H),1.94(2H),1.84(2H),1.52(4H),1.33(2H),1.30(4H),1.29(2H),1.26(8H),1.08(6H),0.89(6H),0.88(3H)。

¹³C NMR(500MHz，CDCl₃),δ178.4,170.8,128.9,128.3,49.7(2C),37.4,33.0,31.9,30.0(2C),29.9,29.7,29.7,29.6,29.6,29.3,27.7,27.3,22.7,20.1(2C),14.1,13.8(2C)。

test example 1

Test for enriching rare earth elements

(1) The compounds prepared in examples 1 to 10 and comparative examples 1 to 3 were used in amounts of (5.13, 5.48, 5.83, 7.24, 5.07, 3.7, 7.0, 9.28, 7.75, 4.39, 5.53, 5.3) g by mass, respectively.

(2) Mixing the above extractive agents with 0.96mL of 10.8mol/L sodium hydroxide aqueous solution, and saponifying at 25 deg.C for 5min to obtain saponified extractive agent viscous liquid with saponification degree of 80%;

(3) and (3) mixing the saponified extractant viscous liquid with 2000mL of ionic rare earth leaching solution at room temperature, and enriching for 0.5 h. The ionic rare earth leaching solution comprises the following components: lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and yttrium, wherein the total molar concentration is 0.00636 mol/L. pH 6.0. And (3) testing the concentration of the rare earth ions in the water phase before and after enrichment, and calculating the total enrichment rate E% of the rare earth ions.

The specific test results (total enrichment of rare earth ions) are shown in table 1:

TABLE 1

Item	Example 1	Example 2	Example 3	Example 4	Example 5	Example 6
							The total enrichment rate E%	98.6	98.2	98.5	97.7	97.9	99.6
Item	Example 7	Example 8	Example 9	Example 10
							The total enrichment rate E%	96.7	96.9	98.5	98.8
Item	Comparative example 1	Comparative example 2	Comparative example 3
							The total enrichment rate E%	91.2	93.8	93.6

As shown in the table above, the enrichment ratio of the N, N-dihydrocarbylamide carboxylic acids of examples 1-10 is above 95%, and the total enrichment ratio of the N, N-dihydrocarbylamide carboxylic acids of comparative examples 1-3 is below 95%, so that the N, N-dihydrocarbylamide carboxylic acid defined by the invention as an extractant can enrich rare earth elements from low-concentration rare earth raw materials, and the enrichment effect is better.

Test example 2

Isolated yttrium ion test

(1) The compounds prepared in the above examples 1-10 and comparative example 1 were prepared into extractant solutions, respectively, and the concrete preparation method of the extractant solution was: the extraction agent used in examples 1 to 10 and comparative example 1 was (5.13, 5.48, 5.83, 7.24, 5.07, 3.7, 7.0, 9.28, 7.75 and 4.39, 5.53, 5.3) g in mass, and the extraction agent solution was prepared by mixing (19.87, 19.52, 19.17, 17.76, 19.93, 21.3, 18.0, 15.72, 17.25 and 20.61, 19.47, 19.7) g in mass, and the concentration of the extraction agent was 0.52 mol/L;

(2) mixing each extractant solution with 0.96mL of 10.8mol/L sodium hydroxide aqueous solution, and saponifying at 25 deg.C for 5min to obtain saponified extractant solution with saponification degree of 80%;

(3) 25mL of saponified extractant solution and 25mL of mixed rare earth solution are mixed at room temperature, and the extraction time is 0.5 h. The mixed rare earth solution comprises the following components: lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and yttrium, wherein the concentration of each element is 0.020 mol/L. The concentrations of rare earth ions in the aqueous phase before and after extraction were measured, and the relative separation coefficient beta of each rare earth ion (Ln) with respect to yttrium ion (Y) was calculated_Ln/Y；

Specific test results (relative separation coefficient beta of rare earth ions (Ln) relative to yttrium ions (Y))_Ln/Y) As shown in table 2:

TABLE 2

As seen from Table 2, the separation coefficients (. beta.) for respective rare earth elements of the N, N-dihydrocarbylamide carboxylic acids of examples 1 to 10_Ln/Y) Separation coefficient (. beta.) higher than that of comparative examples 1 to 3_Ln/Y) The N, N-dialkyl amido carboxylic acid defined by the invention can better separate and purify yttrium element from the mixed rare earth raw material.

Test example 3

Stability test

The compound I-1 prepared in the above example 1 was subjected to a stability test, which specifically comprises the following steps: preparing a compound I-1 into an extractant solution, wherein the specific preparation method of the extractant solution comprises the following steps: mixing 40.7g of the extractant with 100mL of toluene to prepare an extractant solution with the concentration of 1.0 mol/L; 50mL of the extractant solution is mixed with 50mL of hydrochloric acid solution with the concentration of 6mol/L and stirred, and another 50mL of the extractant solution is mixed with 50mL of sodium hydroxide solution with the concentration of 6mol/L and stirred, the stirring is maintained for 15 days, and then the loss rate of the extractant is tested by nuclear magnetic detection.

The stability test methods of the compounds of examples 2 to 10 and comparative example are the same as those of compound I-1.

The specific test results (loss of extractant in hydrochloric acid medium and liquid caustic medium) are shown in table 3 below:

TABLE 3

As can be seen from the test data in Table 3, the loss rate of the N, N-dihydrocarbylamide carboxylic acid of the present invention in hydrochloric acid medium is below 0.05%; the loss rate in a liquid caustic soda medium is below 0.07 percent; it is fully demonstrated that the N, N-dihydrocarbylaminocarboxylic acids prepared according to the present invention are excellent in chemical stability and are resistant to strong acids and bases without decomposition.

The Applicant states that the present invention is illustrated by the above examples of N, N-dihydrocarbylamide carboxylic acids and their preparation and use, but that the invention is not limited to the above examples, which do not mean that the invention must be practiced in any way. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.