Method for preparing albendazole with chloropropane in place of bromopropane

A technology of albendazole and chloropropane, applied in the field of synthesis of imidazole compounds, can solve the problems of poor safety, low yield, high production cost, etc., and achieve the effects of safe production process, reduced environmental hazards, and mild process conditions

Active Publication Date: 2016-11-30
东营睿港投资服务有限责任公司
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] Aiming at the technical problems such as poor safety, low yield and high production cost in the existing albendazole preparation method, the present invention starts from the reaction conditions and the raw materials participating in the reaction, and replaces the higher-priced bromine with lower-priced chloropropane Propane participates in the reaction to provide a method for preparing albendazole with chloropropane instead of bromopropane that is simple to operate, safe in reaction and low in production cost

Method used

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  • Method for preparing albendazole with chloropropane in place of bromopropane
  • Method for preparing albendazole with chloropropane in place of bromopropane
  • Method for preparing albendazole with chloropropane in place of bromopropane

Examples

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Embodiment 1

[0021] Example 1: Add 100.00 g (0.52 mol) of carbendazim, 46.98 g (0.58 mol) of sodium thiocyanate, and 500.00 g of glacial acetic acid in a 1500 mL reaction flask in sequence, and slowly raise the temperature to 35° C. 253.00 g (2.08 mol) of hydrogen peroxide with a mass concentration of 28% was slowly added dropwise under the pressure, and the temperature in the reaction bottle was controlled at 35-37° C. After the hydrogen peroxide is added dropwise, continue to stir at 35°C and keep it warm for 6 hours. After the heat preservation is over, the solid is distilled under reduced pressure to obtain methyl 5-thiocyanobenzimidazole-2-carbamate, and the liquid glacial acetic acid is distilled out. recycle and re-use. After the glacial acetic acid has been distilled, add 1.50 g of benzyltriethylammonium chloride to the solid methyl 5-thiocyanobenzimidazole-2-carbamate, and slowly add 40% hydrogenated ammonium chloride in a stirring state. 110.00 g (1.82 mol) of sodium tetrahydrof...

Embodiment 2

[0022] Example 2: Add 100.00 g (0.52 mol) of carbendazim, 51.03 g (0.63 mol) of sodium thiocyanate, and 600.00 g of glacial acetic acid in a 1500 mL reaction flask in sequence, and slowly raise the temperature to 35° C. 253.00 g (2.08 mol) of hydrogen peroxide with a mass concentration of 28% was slowly added dropwise under the pressure, and the temperature in the reaction bottle was controlled at 35-37° C. After the hydrogen peroxide is added dropwise, continue to stir at 35°C and keep it warm for 4.5 hours. After the heat preservation is over, the solid is distilled under reduced pressure to obtain methyl 5-thiocyanobenzimidazole-2-carbamate, and the liquid ice is distilled off. Acetic acid recycling. After the glacial acetic acid has been distilled, add 2.0 g of benzyltriethylammonium chloride to the solid methyl 5-thiocyanobenzimidazole-2-carbamate, and slowly add 40% hydrogenated ammonium chloride in a stirring state. 124.80 g (2.08 mol) of sodium tetrahydrofuran solutio...

Embodiment 3

[0023]Example 3: 100.00g (0.52mol) of carbendazim, 59.13g (0.73mol) of sodium thiocyanate, and 500.00g of glacial acetic acid were sequentially added to a 1500mL reaction flask, and the temperature was slowly raised to 35°C. 253.00 g (2.08 mol) of hydrogen peroxide with a mass concentration of 28% was slowly added dropwise under the pressure, and the temperature in the reaction bottle was controlled at 35-37° C. After the hydrogen peroxide is added dropwise, continue to stir at 35°C and keep warm for 5 hours. After the keep warm, the solid is distilled under reduced pressure to obtain methyl 5-thiocyanobenzimidazole-2-carbamate, and the liquid glacial acetic acid is distilled out. recycle and re-use. After the glacial acetic acid has been distilled, add 2.00 g of benzyltriethylammonium chloride to the solid methyl 5-thiocyanobenzimidazole-2-carbamate, and slowly add 40% hydrogenated ammonium chloride in a stirring state. 140.40 g (2.34 mol) of sodium tetrahydrofuran solution,...

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Abstract

The invention discloses a method for preparing albendazole with chloropropane in place of bromopropane, and belongs to the technical field of synthesis of imidazole compounds. The method comprises the following steps of firstly, sequentially adding carbendazol, sodium thiocyanate and glacial acetic acid into a reactor, performing uniform stirring, raising the temperature to 35 DEG C, slowly and dropwise adding a hydrogen peroxide solution under a stirring state, and performing a reaction so as to obtain solid 5-sulfhydryl benzimidazole-2-carbaminic acid methylester; preparing a chlorobenzene Grignard reagent by using 1,2-bromofume Grignard reagent; and then adding a phase transfer catalyst namely benzyl triethyl ammonium chloride to the solid 5-sulfhydryl benzimidazole-2-carbaminic acid methylester, slowly and dropwise adding a tetrahydrofuran solution of sodium hydride under the stirring state, performing a reaction for 30 minutes, beginning to slowly and dropwise drop the chlorobenzene Grignard reagent under the stirring condition, and performing a reaction so as to obtain an albendazole product. According to the method disclosed by the invention, the chloropropane is used for replacing the bromopropane which is relatively higher in price, so that not only is the investment cost of reaction raw materials reduced, but also the yield and the purity of the albendazole are guaranteed to be increased.

Description

Technical field: [0001] The invention belongs to the technical field of synthesis of imidazole compounds, and in particular relates to a method for synthesizing albendazole, which uses chloropropane instead of bromopropane to synthesize albendazole. Background technique: [0002] Albendazole (Albendazole, ABZ), also known as albendazole, chemically named 5-propylthio-1H-benzimidazole 2-carbamate methyl ester, is a broad-spectrum high-efficiency and low-toxic anthelmintic. The drug was first listed by the American Smith Kline Company in 1977, and it is widely used clinically to treat various helminth infectious diseases. There are multiple ways about the synthesis of albendazole, and there are two main production methods in the market: the one is the paper "Synthesis of Albendazole" (Zhu Shuigeng, "Chinese Journal of Pharmaceutical Industry" (1990, 21 (5)) Reported in carbendazim as raw material, through four steps such as thiocyanation, thioetherification, reduction and cyc...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D235/32
CPCC07D235/32
Inventor 张千峰陈向莹马森贾爱铨
Owner 东营睿港投资服务有限责任公司
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