CN115819309B

CN115819309B - A high-purity amino acid derivative and its preparation method

Info

Publication number: CN115819309B
Application number: CN202111450807.1A
Authority: CN
Inventors: 汤俊
Original assignee: Yanke Shanghai Biochemical Technology Co ltd
Current assignee: Yanke Shanghai Biochemical Technology Co ltd
Priority date: 2021-12-01
Filing date: 2021-12-01
Publication date: 2026-01-30
Anticipated expiration: 2041-12-01
Also published as: CN115819309A

Abstract

The invention discloses an amino acid derivative with high purity, which comprises, by weight, 1-3 parts of proline, 20-30 parts of an organic solvent, 0.5-1 part of a polypeptide condensing agent, 0.1-0.5 part of a nucleophilic catalyst and 1-1.5 parts of an amino protective agent. According to the invention, the esterification reaction is carried out under a milder condition by controlling the reaction speed of the raw materials, and methyl proline is generated as much as possible under the action of diisopropylcarbodiimide, so that the reaction yield is improved. Moreover, the protection effect of the tert-butyloxycarbonyl ester on the proline amino is further enhanced by adding the alkylamino pyridine compound, so that the reaction between the methyl ester intermediate and the amino is reduced, and the generation of an amide group is avoided. Meanwhile, the reaction condition is mild, and the generated product can realize higher purity without complex subsequent separation, and can be used as an intermediate of various medicines.

Description

High-purity amino acid derivative and preparation method thereof

Technical Field

The invention relates to an amino acid derivative with high purity and a preparation method thereof, in particular to C07D, and particularly relates to the field of heterocyclic compounds.

Background

The polypeptide medicine prepared from the amino acid derivative has become a hot spot for medicine development, has wide application of the polypeptide medicine, high safety and is applied to prevention, diagnosis and treatment of various diseases. The proline medicine has good permeability in organisms, is commonly used as a permeation regulator, can also be used as a protective agent of enzymes, and has the function of scavenging free radicals. The hydroxyproline methyl ester is used as a medical intermediate, can be used for research and development of various polypeptide medicaments, and has great significance for research and development of medicaments, wherein the hydroxyproline methyl ester is high in purity and good in yield.

Chinese patent No. CN112194606A discloses a preparation method of N-BOC-cis-4-hydroxy-L-proline methyl ester, L-hydroxyproline is adopted as a raw material, amino BOC is used for protection first, methyl esterification is carried out, the obtained proline methyl ester has higher yield, but the reaction time is longer, chinese patent No. CN201080051130 discloses a preparation method of N-Boc-cis-amino-L-proline methyl ester, trans-hydroxyproline is adopted as a raw material, sodium azide is needed to be added for chiral conversion, and BOC deprotection is easily caused in the reaction process, so that the yield is influenced.

Disclosure of Invention

In order to improve the preparation purity of the proline derivative and reduce the generation of byproducts, the first aspect of the invention provides an amino acid derivative with high purity, and the preparation raw materials comprise, by weight, 1-3 parts of proline, 20-30 parts of an organic solvent, 0.5-1 part of a polypeptide condensing agent, 0.1-0.5 part of a nucleophilic catalyst and 1-1.5 parts of an amino protecting agent.

As a preferred embodiment, the proline is selected from one or a combination of several of L-proline, D-proline and DL-proline.

As a preferred embodiment, the L-proline is selected from one or a combination of several of 4-hydroxy-L-proline, L-thioproline, L-aminoproline, L-amidoproline.

As a preferred embodiment, the proline is 4-hydroxy-L-proline.

As a preferred embodiment, the organic solvent is selected from one or a combination of several of hydrocarbon solvents, alcohol solvents, ester solvents, phenol solvents, ketone solvents, and furans.

As a preferred embodiment, the organic solvent used in the step 1 is chloroform and methanol, the organic solvent used in the step 2 is tetrahydrofuran, and the organic solvent used in the step 3 is a combination of chloroform and petroleum ether.

As a preferred embodiment, the organic solvent is added in an amount of 8-12 parts by weight of chloroform and 1-2 parts by weight of methanol in the step 1, 10-15 parts by weight of tetrahydrofuran in the step 2, and the volume ratio of the chloroform to petroleum ether in the step 3 is (3-5): 1.

As a preferred embodiment, the organic solvent is added in an amount of 9-11 parts by weight of chloroform and 1.2-1.8 parts by weight of methanol in the step 1, 11-14 parts by weight of tetrahydrofuran in the step 2, and the volume ratio of the chloroform to petroleum ether in the step 3 is (4-5): 1.

As a preferred embodiment, the organic solvent is added in an amount of 10 parts by weight of chloroform and 1.5 parts by weight of methanol in the step 1, 13 parts by weight of tetrahydrofuran in the step 2, and the volume ratio of the chloroform to petroleum ether in the step 3 is 4.5:1.

As a preferred embodiment, the polypeptide condensing agent is selected from one or a combination of a plurality of carbodiimide condensing agents, phosphorus positive ion condensing agents and urea positive ion condensing agents.

As a preferred embodiment, the carbodiimide condensing agent is one selected from diisopropylcarbodiimide, 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride, dicyclohexylcarbodiimide.

As a preferred embodiment, the polypeptide condensing agent is diisopropylcarbodiimide.

As a preferred embodiment, the nucleophilic catalyst is selected from one or a combination of several of an alkylamino pyridine compound or an allylaminopyridine.

As a preferred embodiment, the alkylamino pyridine compound is N-methyl-N- (glycidylamino pyridine).

The preparation method of the N-methyl-N- (epoxypropyl) aminopyridine comprises the following steps of mixing bipyridine hydrochloride and methylamine hydrochloride with a weight ratio of 2:1, adding ethyl acetate, stirring and refluxing for 5 hours, adding triethylamine with a mass concentration of 40%, controlling the pH value to be 11-12, filtering under reduced pressure, taking a filter cake, mixing with triethylamine with a mass concentration of 50%, dripping epichlorohydrin, stirring and refluxing for 4 hours, distilling under reduced pressure, and drying to obtain solid N-methyl-N- (epoxypropyl) aminopyridine.

As a preferred embodiment, the amino protecting agent is selected from one or a combination of several of carbonyl ester, phthalimide, phthalamide, p-benzenesulfonamide and trifluoroacetamide.

As a preferred embodiment, the carbonyl ester is selected from one or a combination of several of t-butoxycarbonyl ester, benzyloxycarbonyl ester, biphenyl-2-propoxycarbonyl ester.

As a preferred embodiment, the amino protecting agent is t-butoxycarbonyl ester.

The applicant finds that in the experimental process, the 4-hydroxy-L-proline and methanol can fully perform carboxyl methyl esterification reaction under the action of the catalyst diisopropylcarbodiimide, and methanol is added in a dropwise manner, so that the reaction condition is mild. The addition of the alkylamino pyridine compound can further increase the protection effect of the tert-butoxycarbonyl ester on the amino acid, enable the tert-butoxycarbonyl ester to be connected to a proline heterocycle, reduce the intensity of reaction by dripping the tert-butoxycarbonyl ester, and control the methyl ester intermediate not to react with the amino group on the amino acid, thereby avoiding the generation of an amide group. And the pH value of the system is controlled in the reaction process, so that chiral turnover of amino acid is prevented.

In a second aspect, the present invention provides a method for producing an amino acid derivative having high purity, comprising the steps of:

(1) Adding proline and a polypeptide condensing agent into an organic solvent, stirring at room temperature for reaction for 6-8h, and performing reduced pressure filtration after the reaction is completed to obtain a white solid;

(2) Adding the white solid obtained in the step 1 and a nucleophilic catalyst into an organic solvent, mixing and stirring, controlling the reaction temperature to be 25-40 ℃, reacting for 1-2h, dropwise adding an amino protective agent, and reacting for 6-8h;

(3) And (3) washing the solid product by using an organic solvent through reduced pressure filtration, repeatedly washing for 3 times, taking white solid, and drying to obtain the product.

In a preferred embodiment, step 1 is to add proline and polypeptide condensing agent into chloroform, react for 1-2h at room temperature, then drop methanol, drop methanol within 40-50min, react for 5-6h under continuous stirring, and filter under reduced pressure after the reaction is completed, thus obtaining white solid.

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

(1) According to the proline derivative, the esterification reaction is carried out under a milder condition by controlling the reaction speed of raw materials, and methyl proline is produced as much as possible under the action of diisopropylcarbodiimide, so that the reaction yield is improved.

(2) According to the proline derivative, the protection effect of tert-butoxycarbonyl ester on proline amino is further improved by adding the alkylamino pyridine compound, the reaction of methyl ester intermediate and amino is reduced, and the generation of amide groups is avoided.

(3) The proline derivative provided by the invention has mild reaction conditions, and the generated product can realize higher purity without complex subsequent separation, and can be used as an intermediate of various medicines.

Detailed Description

The present invention will be specifically described below by way of examples. It is noted herein that the following examples are given solely for the purpose of further illustration and are not to be construed as limitations on the scope of the invention, as will be apparent to those skilled in the art in light of the foregoing disclosure.

In addition, the raw materials used are commercially available unless otherwise indicated.

Example 1

The amino acid derivative with high purity is prepared from (by weight parts) proline 3, organic solvent 28, polypeptide condensing agent 0.75, nucleophilic catalyst 0.35, and amino protecting agent 1.3.

The proline is 4-hydroxy-L-proline, available from Porphyra tenera (Shanghai) chemical industry development Co., ltd.

The polypeptide condensing agent is diisopropylcarbodiimide.

The nucleophilic catalyst is N-methyl-N- (epoxypropyl) aminopyridine, and the preparation method comprises the following steps of mixing 2 parts by weight of 4, 4-bipyridine dihydrochloride (CAS: 27926-72-3) with 1 part by weight of methylamine hydrochloride (CAS: 593-51-1), adding ethyl acetate, stirring and refluxing for 5 hours, adding triethylamine with the mass concentration of 40%, controlling the pH value to be 12, filtering under reduced pressure, taking all filter cakes to be mixed with triethylamine with the mass concentration of 50%, controlling the pH value to be 12, dropwise adding epichlorohydrin, enabling the weight ratio of epichlorohydrin to 4, 4-bipyridine dihydrochloride to be 2:1, stirring and refluxing for 4 hours, distilling under reduced pressure, and drying to obtain solid N-methyl-N- (epoxypropyl) aminopyridine.

The amino protective agent is tert-butyloxycarbonyl ester.

A method for producing an amino acid derivative having a high purity, comprising the steps of:

(1) Adding proline and a polypeptide condensing agent into chloroform, reacting for 1.5 hours at room temperature, then dropwise adding methanol, reacting for 5 hours under continuous stirring after dropwise adding in 40 minutes, and filtering under reduced pressure after the reaction is completed to obtain a white solid;

(2) Adding the white solid obtained in the step 1 and a nucleophilic catalyst into an organic solvent, mixing and stirring, controlling the reaction temperature to be 30 ℃, reacting for 2 hours, dropwise adding an amino protective agent, and reacting for 8 hours;

The organic solvent adopted in the step 1 is 10 parts by weight of chloroform and 1.5 parts by weight of methanol, the organic solvent adopted in the step 2 is 13 parts by weight of tetrahydrofuran, and the organic solvent adopted in the step 3 is a combination of chloroform and petroleum ether, wherein the volume ratio is 4.5:1.

Example 2

An amino acid derivative with high purity and a preparation method thereof are provided, and specific steps are the same as in example 1, except that the polypeptide condensing agent is dicyclohexylcarbodiimide.

Example 3

An amino acid derivative with high purity and a preparation method thereof are provided, and the specific steps are the same as in example 1, except that the nucleophilic catalyst is dimethylaminopyridine.

Example 4

An amino acid derivative with high purity and a preparation method thereof are provided, and specific steps are the same as those of example 1, except that the volume ratio of chloroform to petroleum ether in the step3 is 3:1.

Performance testing

1. Purity by adding the sample to an HPLC-MS instrument, and finding the concentration of the corresponding proline derivative on a standard curve with the total area of the peaks, purity = c proline derivative/c white solid =100%

2. Yield = m _{White solid}/(m_{Proline (proline)}+m_{polypeptide condensing agent}+m_{Amino protective agent}) 100%

Examples 1-4 were tested according to the criteria described above and the test results are shown in Table 1.

TABLE 1

	Purity/%	Yield/%
			Example 1	98.52	90.31
Example 2	95.33	86.02
			Example 3	90.01	91.32
Example 4	95.89	85.42

Claims

1. A high-purity amino acid derivative, characterized in that the raw materials for preparation are, by weight: 1-3 parts proline, 20-30 parts organic solvent, 0.5-1 part polypeptide condensing agent, 0.1-0.5 parts nucleophilic catalyst, and 1-1.5 parts amino protecting agent;

The proline is 4-hydroxy-L-proline; the polypeptide condensing agent is diisopropylcarbodiimide; the catalyst is N-methyl-N-(epoxypropylene)aminopyridine;

The preparation method of the N-methyl-N-(epoxypropane)aminopyridine includes the following steps: mixing bipyridine hydrochloride and methylamine hydrochloride at a weight ratio of 2:1, adding ethyl acetate and stirring under reflux for 5 hours, adding triethylamine with a mass concentration of 40%, controlling the pH value to 11-12, filtering under reduced pressure, taking the filter cake and mixing it with triethylamine with a mass concentration of 50%, adding epichlorohydrin dropwise, stirring under reflux for 4 hours, distilling under reduced pressure, and drying to obtain solid N-methyl-N-(epoxypropane)aminopyridine;

The amino protecting agent is tert-butyloxycarbonyl ester (BOC).

The method for preparing the high-purity amino acid derivative includes the following steps:

(1) Add proline and polypeptide condensing agent to an organic solvent and stir the reaction at room temperature for 6-8 hours. After the reaction is complete, filter under reduced pressure to obtain a white solid.

(2) Take the white solid obtained in step 1 and the nucleophilic catalyst and add them to an organic solvent to mix and stir. Control the reaction temperature to 25-40℃ and react for 1-2 hours. Add an amino protectant and react for 6-8 hours.

(3) The solid product was washed with organic solvent by vacuum filtration. The washing was repeated 3 times. The white solid was taken and dried.

2. The high-purity amino acid derivative according to claim 1, wherein the organic solvent is selected from one or a combination of several of hydrocarbon solvents, alcohol solvents, ester solvents, phenol solvents, ketone solvents, and furans.

3. A method for preparing a high-purity amino acid derivative according to any one of claims 1-2, characterized in that it comprises the following steps: