New method for preparing thiabendazole

A technology of thiabendazole and thiazole, which is applied in the field of drug synthesis, can solve the problems of high reaction temperature, low yield, unfavorable environmental protection, etc., and achieve the effect of high atom utilization rate and beneficial to green chemistry

Inactive Publication Date: 2015-04-29
YANTAI BESTENPHARM TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] Such as CN1042150A is a kind of technique of producing thiabendazole by tartaric acid, is made up of five steps namely (1) pyruvic acid is made by tartaric acid cracking; (2) bromopyruvate is generated by pyruvic acid bromination; Amide reaction to prepare thioformamide; (4) bromopyruvate reacts with thioformamide to generate thiazole carboxylic acid hydrobromide; (5) thiazole carboxylic acid hydrobromide reacts with o-phenylenediamine to generate thiabendazole (synthetic route is as follows); although this technique raw material is cheap and easy to get, but the first step reaction temperature is very high and yield is low, economically uneconomical, and also needs to use thioformamide later on, is unfavorable for environmental protection

Method used

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  • New method for preparing thiabendazole
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  • New method for preparing thiabendazole

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0056] 1.1) Preparation of monochloroacetone

[0057] Add 200g of acetone, 20g of calcium carbonate and 10mL of water into a 500mL four-necked bottle, connect the rectification column, and connect the chlorination reactor and condenser at the upper port of the column; start to heat up and reflux, pass chlorine gas, and stop the chlorine flow when the temperature rises to 100°C , to end the reaction. The reactants contained 1.8% of acetone, 95.4% of monochloroacetone, 1.2% of 1,1-dichloroacetone and 1.6% of other impurities according to gas phase detection.

[0058] 1.2) Synthesis of 2-amino-4-methylthiazole

[0059] Add 113.88 g (1.50 mol) of thiourea directly to the monochloroacetone reaction solution (containing 125 g of monochloroacetone, 1.36 mol), stir to form a suspension, and heat to reflux in a water bath for 5 h. The reaction solution was poured into a beaker containing 500 g of ice-water mixture, cooled in a cryopump, and then 200 g of sodium hydroxide was added wi...

Embodiment 2

[0069] 2.1) Preparation of monochloroacetone

[0070] Add 200g of acetone and 10mL of water into a 500mL four-necked flask, raise the temperature and reflux to flow chlorine, slowly add 20% aqueous sodium hydroxide solution into the reaction flask to make the pH of the feed solution = 3-4, and stop the flow when the temperature rises to 100°C. Chlorine ends the reaction. The reactants contained 2.0% of acetone, 94.2% of monochloroacetone, 1.5% of 1,1-dichloroacetone and 2.3% of other impurities according to gas phase detection.

[0071] 2.2) Synthesis of 2-mercapto-4-methylthiazole

[0072] Mix monochloroacetone (74.0g, 0.8mol) with 200mL of water, adjust the pH to 2 with dilute hydrochloric acid, cool the mixture to 40°C, then add a solution of ammonium dithiocarbamate (132g, 1.2mol) and 50mL of water , the reaction mixture was stirred at 40°C for 5 h, and after the reaction was stopped, the pH was adjusted to 9 with sodium hydroxide, extracted with 3*100 mL of ethyl acetat...

Embodiment 3

[0082] 3.1) Preparation of monochloroacetone

[0083] Add 180g of acetone, 30g of calcium carbonate and 10mL of water into a 500mL four-necked bottle, connect the rectification column, and connect the chlorination reactor and condenser at the upper port of the column; start to heat up and reflux, pass chlorine gas, and stop the chlorine flow when the temperature rises to 110°C , to end the reaction. The gas phase detection of the reactant contained 2.1% of acetone, 95.6% of monochloroacetone, 1.4% of 1,1-dichloroacetone, and 0.9% of other impurities.

[0084] 3.2) Synthesis of 2-amino-4-methylthiazole

[0085] Add 113.88 g (1.50 mol) of thiourea directly to the reaction liquid of chloroacetone (containing 115 g of 1.25 mol of chloroacetone), stir to form a suspension, and heat to reflux in a water bath for 6 hours. The reaction solution was poured into a beaker containing 480g of ice-water mixture, cooled in a cryopump, and then 180g of sodium hydroxide was added with stirri...

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Abstract

The invention relates to a new method for synthesizing thiabendazole. Acetone and chlorine are taken as starting materials to synthesize chloroacetone, chloroacetone not subjected to separation can directly react with thiocarbamide to obtain 2-Amino-4-methylthiazole which is subjected to diazotization to obtain 4-methylthiazole, and 4-methylthiazole is oxidized to produce 4-thiazolecarboxylic acid, and finally, 4-thiazolecarboxylic acid reacts with o-phenylenediamine to obtain the target object thiabendazole. The thiabendazole is a broad-spectrum anthelmintic, can repel roundworms, hookworms, whipworms, pinworms, strongyloises stercoralis and trichinization, is also a broad-spectrum efficient disinfectant and is widely used as a fruit fresh-keeping agent and a bactericidal mildew inhibitor in various fields over the past decade in China.

Description

technical field [0001] The invention relates to a drug synthesis method, in particular to a new synthesis method of a compound with the common name Thiabendazole, and belongs to the field of chemical synthesis. Background technique [0002] Thiabendazole, also known as Thiabendazole and Tibendazole, or TBZ for short, is an excellent anti-mold preservative. It is mainly used for fruit and vegetable preservation, food antisepsis and daily necessities such as grain, cloth, decorative materials, etc. It has the characteristics of high efficiency, broad spectrum, low toxicity, and less residue, so it has been approved in the food additive standards of various countries in the world. Anti-mold and preservation of fruits and vegetables. [0003] Have a lot of document patents to also publicly report the synthetic method of thiabendazole at present, as shown in following synthetic route: use lactic acid and o-phenylenediamine as starting raw material, first generate 2-hydroxyethylb...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D417/04
CPCC07D417/04
Inventor 毕海东支彩霞张艺兴
Owner YANTAI BESTENPHARM TECH CO LTD
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