Method for synthesizing albendazole

A kind of technology of albendazole and synthetic method, applied in the field of organic synthesis, can solve the problems of high cost, large amount of glacial acetic acid, etc.

Inactive Publication Date: 2008-12-31
徐州诺特化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

This synthetic route consumes a large amount of glacial

Method used

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  • Method for synthesizing albendazole

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Experimental program
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Effect test

Embodiment 1

[0013] The preparation of 5-nitrobenzimidazole-2-carbamate methyl ester (3): in 500ml there-necked flask, add benzimidazole-2-carbamate methyl ester 20g (0.1mol), concentrated sulfuric acid 20ml, reduce to 0 ℃, and controlled below 0~5℃, add 20ml of fuming nitric acid dropwise, after the dropwise addition, keep warm and stir for reaction (below 10℃) for 2h. The reactant was poured into ice water, and a light yellow solid was precipitated, which was suction filtered, washed with water, and dried to obtain (3) 18.2 g of a light yellow solid, yield 77.0%, mp: 112-114°C.

[0014] The preparation of 5-aminobenzimidazole-2-methyl carbamate (4): add 17g (3) (0.07mol) and 2g of bone nickel suspended in 30ml absolute ethanol to a 250ml autoclave, turn off the high pressure The kettle, add hydrogen from the steel cylinder (pressure 7.5MPa, temperature 6°C), start the reaction at about 55°C, and keep the pressure in the kettle at 0.05-0.30MPa. When the hydrogen is no longer absorbed (ab...

Embodiment 2

[0020] The preparation of 5-nitrobenzimidazole-2-methyl carbamate (3): in a 500ml there-necked flask, add 22g (0.11mol) of benzimidazole-2-methyl carbamate, 30ml of concentrated sulfuric acid, and reduce to 0 Below 5°C, and controlled below 5°C, add 20ml of fuming nitric acid dropwise, after the dropwise addition, stir the reaction (below 5°C) for 2 hours, pour the reactant into ice water, and precipitate a pale yellow solid, filter with suction, wash with water, and dry to obtain ( 3) 20.3 g of light yellow solid, yield 78.0%, mp: 112-114°C.

[0021] Preparation of methyl 5-aminobenzimidazole-2-carbamate (4): Add 25.5 g (3) (0.105 mol) and 3 g of bone nickel suspended in 50 ml of absolute ethanol to a 250 ml autoclave, close In the autoclave, add hydrogen from the steel cylinder (pressure 75atm, temperature 6°C), start the reaction at about 60°C, and keep the pressure in the kettle at 0.05-0.30Mpa. When the hydrogen is no longer absorbed (about 60 ~ 90), turn off the heater,...

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Abstract

The invention relates to a synthetic methodsynthesis method for albendazole, which is characterized in that benzimidazole -2 - methyl carbamate (carbendazim) is taken as raw material to generare 5-nitrobenzene and imidazole -2-methyl carbamate through nitration reaction, or generare 5- amino benzimidazole -2 - methyl carbamate through reduction reaction, or generate 5 - amino benzimidazole -2 - methyl carbamate through diazotization and substitution reaction, or generate albendazole through alkylation reaction. The method of the invention has simple and convenient synthetic route, mild conditions and high product quality, with the total yield reaching more than 58%.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and relates to an organic synthesis method of albendazole. Background technique [0002] Albendazole is an important pesticide and insecticide. It is a high-efficiency broad-spectrum anthelmintic. It is suitable for expelling roundworms, pinworms, hookworms and whipworms, treating various types of cysticercosis, and can also be used for deworming livestock. At present, the industrialized production of albendazole in China generally adopts the synthetic route of using o-nitroaniline as a raw material through esterification, etherification, reduction and ring closure (Zhu Shuigeng, Gao Hongwu, etc., Chinese Journal of Pharmaceutical Industry, 1992, 23: 92 -93). The synthesis process has problems such as high cost and environmental pollution. In China, Li Anliang and others used carbendazim as the starting material to prepare albendazole through reactions such as thiocyanation, hydrolys...

Claims

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Application Information

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IPC IPC(8): C07D235/32A01P7/00
Inventor 王玉成高玉忠王理想王友志杨凯王圣良胡晓曹再林张春来张文娟靳长娟徐安民王乃剑
Owner 徐州诺特化工有限公司
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