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D-cysteine hydrochloride monohydrate preparation method

A technology of cysteine ​​hydrochloride and monohydrate, which is applied in the field of preparation of D-cysteine ​​hydrochloride monohydrate and can solve the problem of ring opening of D-4-tetrahydrothiazole-4-carboxylic acid Difficulties, poor optical purity, low product yield, etc., to achieve the effects of high product yield, high chemical purity, and short drying time

Inactive Publication Date: 2011-11-09
四平市精细化学品有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In this method, the ring opening of D-4-tetrahydrothiazole-4-carboxylic acid is difficult, and racemization also occurs
The product yield is not high, only about 30%, and the optical purity is not good

Method used

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  • D-cysteine hydrochloride monohydrate preparation method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] (1), D-2, the preparation of 2-dimethyltetrahydrothiazole-4-carboxylic acid-L-tartrate double salt:

[0037] Add 384g of L-cysteine, 480g of L-tartaric acid, 1600ml of acetone and 1200ml of acetic acid into the reaction bottle, stir and dissolve and heat to reflux, reflux for 0.5h, then add 26ml of salicylaldehyde, reflux for 20h, cool to 0 with an ice-water bath ℃, filtered, the filter cake was washed twice with the filtrate, and then washed with acetone until it was colorless, and dried to obtain 728g of D-2,2-dimethyltetrahydrothiazole-4-carboxylic acid-L-tartrate double salt.

[0038] (2), the preparation of D-cysteine:

[0039] Dissolve 728g of D-2,2-dimethyltetrahydrothiazole-4-carboxylic acid-L-tartaric acid double salt in 4050ml of water, heat to reflux for 1.5h, then concentrate the reaction solution to about 400ml, adjust the system with 275ml of triethylamine PH = 3.6, then add 2100ml of ethanol, stir for 10 minutes, cool down to 20°C, filter and dry to obta...

Embodiment 2

[0043] (1) Prepare 728g of D-2,2-dimethyltetrahydrothiazole-4-carboxylic acid-L-tartrate double salt according to (1) in Example 1, dissolve in 4050ml of water, heat to reflux for 1.5h, add 35g Activated carbon, stirred for 15 minutes, filtered to remove the activated carbon, concentrated the reaction solution to about 400ml, adjusted the pH of the system to 3.6 with 275ml of triethylamine, then added 2100ml of ethanol, stirred for 10 minutes, cooled to 20°C, filtered, dried to obtain D-cysteine Acid 405.2g.

[0044] (2), the preparation of D-cysteine ​​hydrochloride monohydrate:

[0045] Add 405.2g of the prepared D-cysteine ​​into the mixed solution composed of 400ml concentrated hydrochloric acid, stir and react at 40°C for 30 minutes, then let it stand and cool down to about -5°C, filter the precipitated white crystals, and put them in ice acetone Wash and dry to obtain about 406.2 g of D-cysteine ​​hydrochloride monohydrate. The chemical purity is 99.23%, and the yield ...

Embodiment 3

[0047] (1), D-2, the preparation of 2-dimethyltetrahydrothiazole-4-carboxylic acid-L-tartrate double salt:

[0048] Add 384g of L-cysteine, 480g of L-tartaric acid, 1,600ml of acetone and 1,800ml of propionic acid into the reaction bottle, stir and dissolve and heat to reflux, reflux for 0.5h, then add 26ml of salicylaldehyde, reflux for 20h, and cool down to 0°C, filtered, the filter cake was washed twice with the filtrate, and then washed with acetone until it was colorless, and dried to obtain D-DMTL-TA776g.

[0049] (2), the preparation of D-cysteine ​​hydrochloride monohydrate:

[0050] According to (2) (3) step in example 1, 776gD-2,2-dimethyltetrahydrothiazole-4-carboxylic acid-L-tartrate double salt is prepared to obtain D-cysteine ​​hydrochloride monohydrate 434.6g, chemical purity 99.19%, yield 78.03%.

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Abstract

The invention discloses a preparation method of an intermediate D-cysteine hydrochloride monohydrate which is used for synthetizing third generation cephalosporin antibiotic cefminox sodium. The preparation method comprises the following steps: taking L-cysteine, acetone and L-tartaric acid as raw materials which are subjected to a reaction with acetone and acetate (or propionic acid) mediums, utilizing an asymmetric transforming agent salicylic aldehyde to carry out asymmetric transformation to form D-2,2-dimethyl thiazolidine-4-carboxylic acid-L-tartrate; carrying out hydrolyzation, crystallization, filteration and drying treatments on double salt to obtain D-cysteine; generating hydrochloride after a reaction between the D-cysteine and hydrochloric acid with a content of 16-31%, and carrying out dissolving, decolouring, distillation and recrystallization treatments to obtain the D-cysteine hydrochloride-hydrate product. The preparation method in the invention has the advantages of simple process, high product yield, high chemical purity and high optical purity. Recycle and reuse of input solvent and unreacted raw material facilitate industrialization production.

Description

technical field [0001] The present invention relates to a kind of preparation method of the intermediate of synthetic third-generation cephalosporin antibiotic cefminox sodium, more specifically, it relates to a kind of preparation method of D-cysteine ​​hydrochloride monohydrate. Background technique [0002] D-cysteine ​​hydrochloride monohydrate is an intermediate in the synthesis of the third-generation cephalosporin antibiotic cefminox sodium. Cefminox sodium has unique dual effects, broad antibacterial spectrum, rapid and powerful sterilization, and remarkable curative effect. It can be used for respiratory tract infection, urinary system infection, pelvic infection, sepsis and other infections. D-cysteine ​​hydrochloride monohydrate as its indispensable intermediate, the existing preparation of D-cysteine ​​hydrochloride monohydrate has the following methods: [0003] 1. Formaldehyde method: using L-cysteine ​​as raw material, reacting with formaldehyde to prepare D-...

Claims

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Application Information

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IPC IPC(8): C07C323/58C07C319/02C07C319/12
Inventor 薛亮吴金河王春艳刘长宝王宏禹
Owner 四平市精细化学品有限公司
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