Preparation methoh of tinidazole

A technology of tinidazole and nitroimidazole, which is applied in the field of preparation of antifungal drug tinidazole, can solve the problems of low yield, black color of intermediate products, high price, etc., and achieve increased solvent recovery and reduced dosage , The effect of production cost reduction

Inactive Publication Date: 2004-02-18
ZHEJIANG UNIV
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  • Description
  • Claims
  • Application Information

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Problems solved by technology

The shortcoming of this method is that the yield of the first and third steps is not high, and different literature reports are respectively 66%, 83% for the first step, and 54% for the third step, and use expensive phase transfer catalysts and a large amount of disulfuric acid ethyl ester; followed by the second step using a very large amount of NaBr and ZnCl 2 , not only the color of the intermediate product is black, but also the product needs to use a large amount of ammonia water to adjust the pH value, which will generate a large amount of waste water and waste residue

Method used

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  • Preparation methoh of tinidazole

Examples

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Effect test

Embodiment 1

[0012] 62g (1.0mol) ethanethiol is added in the 500ml reaction bottle, slowly add the industrial sodium methylate of 200g (1.04mol) 28%, the solution becomes pale yellow immediately, keep at room temperature then, slowly add dropwise by 80.6g (1.0 mol) of chloroethanol and 50ml methanol, the dropwise addition was completed, reacted at room temperature for 1 hour, then slowly heated to 80 ° C, and reacted for 3 hours. The cake was rinsed with methanol, dried for later use, the mother liquor was distilled to recover the methanol, and the residue was distilled under reduced pressure to collect fractions at 101-103°C / 50mmHg. 96.5%.

Embodiment 2

[0014] The sodium methoxide was replaced by an ethanol solution of sodium ethoxide, and the ethanol solution of chloroethanol was added dropwise. Other operations were the same as in Example 1 to obtain 101.8 g of β-hydroxyethyl sulfide, with a yield of 96%.

Embodiment 3

[0016] The sodium methoxide was replaced with a tert-butanol solution of sodium tert-butoxide, and pure chloroethanol was added dropwise. The other operations were the same as in Example 1 to obtain 103.1 g of β-hydroxyethyl sulfide with a yield of 97.3%.

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Abstract

A process for preparing tinidazole from ethiol and chloroethanol includes removing sodium at ordinary temp-100 deg.C in alkaline condition, vacuum distilling to obtain beta-hydroxyethioether, condensation reaction on 2-methyl-5-nitroimidazole in methyl substituted 2-pentone under action of ZnCl2 and sodium chloride to obtain 1-(beta-ethioethyl)-2-methyl-5-nitroimidazole, and catalytic oxidizing by hydrogen peroxide and concentrated sulfuric acid. Its advantages are high output rate, low cost and less environmental pollution.

Description

technical field [0001] The invention relates to a preparation method of antifungal drug tinidazole. Background technique [0002] The main preparation method (U.S. Patent US4160096, Chinese Patent Publication No. CN1053896C) of existing tinidazole is: the first step is starting raw material with mercaptoethanol, adopts quaternary ammonium salt as phase-transfer catalyst under alkaline condition, with disulfuric acid The ethyl ester is ethylated to obtain β-hydroxy ethyl sulfide; the second step of β-hydroxy ethyl sulfide is in 4-methyl-2-pentanone with ZnCl 2 Catalysis, HCl gas or NaBr, KI and H 2 SO 4 , and then condensed with 2-methyl-5-nitroimidazole to obtain the condensation product 1-(β-ethylthioethyl)-2-methyl-5-nitroimidazole; then the third step uses 30% hydrogen peroxide After oxidation under acidic conditions, adjust the pH to neutral with NaOH or ammonia water to obtain the product tinidazole with a total yield of 40% in three steps. Th...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D233/94
Inventor 戴立言
Owner ZHEJIANG UNIV
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