Chemical synthesis method for 2-hydroxybenzimadazoles

A technology for hydroxybenzimidazole and chemical synthesis, applied in the direction of organic chemistry and the like, can solve the problems of large environmental pollution, long steps, low yield and the like, and achieve the effects of less three wastes, low production cost and reasonable process conditions

Inactive Publication Date: 2008-07-02
WENZHOU UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

There are also reports that ethyl anthranilate and hydroxylamine are used as raw materials, and 2-hydroxybenzimidazole is obtained under the effects of benzenesulfonyl chloride and sodium hydroxide, etc., but this method has long steps and low yield, which is harmful to the environment. Pollution is relatively large

Method used

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  • Chemical synthesis method for 2-hydroxybenzimadazoles
  • Chemical synthesis method for 2-hydroxybenzimadazoles
  • Chemical synthesis method for 2-hydroxybenzimadazoles

Examples

Experimental program
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Effect test

Embodiment 1

[0025] The amount of feeding material is o-phenylenediamine, two (trichloromethyl) carbonate, pyridine=1: 0.4: 2.0, the feeding amount of o-phenylenediamine is 250mmol, the feeding amount of two (trichloromethyl) carbonate is 100mmol, the feeding amount of pyridine is 500mmol, and the organic solvent is methylene chloride 540ml, and its volume consumption is 20 times of the quality of o-phenylenediamine.

[0026] In a 500ml three-neck flask equipped with mechanical stirring, a constant pressure dropping funnel and a thermometer, 27g of o-phenylenediamine, 400ml of dichloromethane and 40ml of pyridine were sequentially added, and the temperature of the mixture was controlled at 10°C. Slowly add 140ml of dichloromethane solution that is dissolved with 29.7g of bis(trichloromethyl)carbonate in the mixed solution dropwise, continue to maintain the temperature and stir for 4h after the dropwise addition, filter, wash the filter cake with 100ml of dichloromethane, and then use 120ml ...

Embodiment 2

[0028] The amount of feeding material is o-phenylenediamine, two (trichloromethyl) carbonate, pyridine=1: 0.4: 3.0, the feeding amount of o-phenylenediamine is 250mmol, the feeding amount of two (trichloromethyl) carbonate is 100mmol, the feeding amount of pyridine is 750mmol, and the organic solvent is methylene chloride 540ml, and its volume consumption is 20 times of the quality of o-phenylenediamine.

[0029] In a 500ml three-neck flask equipped with mechanical stirring, a constant pressure dropping funnel and a thermometer, 27g of o-phenylenediamine, 400ml of dichloromethane and 60ml of pyridine were sequentially added, and the temperature of the mixture was controlled at -5°C. Slowly add 140ml of dichloromethane solution that is dissolved with 29.7g of bis(trichloromethyl)carbonate in the mixed solution dropwise, continue to maintain the temperature and stir for 4h after the dropwise addition, filter, wash the filter cake with 100ml of dichloromethane, and then use 120ml ...

Embodiment 3

[0031] The amount of feeding material is o-phenylenediamine, two (trichloromethyl) carbonate, pyridine=1: 0.4: 2.0, the feeding amount of o-phenylenediamine is 250mmol, the feeding amount of two (trichloromethyl) carbonate is 100mmol, the feeding amount of pyridine is 500mmol, and the organic solvent is methylene chloride 432ml, and its volume consumption is 16 times of the quality of o-phenylenediamine.

[0032] In a 500ml three-necked flask equipped with mechanical stirring, a constant pressure dropping funnel and a thermometer, 27g of o-phenylenediamine, 290ml of dichloromethane and 40ml of pyridine were sequentially added, and the temperature of the mixture was controlled at 30°C. Slowly add 142ml of dichloromethane solution that is dissolved with 29.7g of bis(trichloromethyl)carbonate in the mixed solution dropwise, continue to maintain the temperature and stir for 4h after the dropwise addition, filter, wash the filter cake with 100ml of dichloromethane, and then use 120m...

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Abstract

The invention relates to a chemical synthesis method of 2-hydroxy benzimidazole, which takes o-diaminobenzene and bis (trichloromethyl) carbonate as raw materials. The raw materials are put into organic solvent for react for 1-13h at -10-80 DEG C with the effect of organic alkali, after-treatment is carried out to reaction solution to get the 2- hydroxy benzimidazole. The chemical synthesis method of the 2- hydroxy benzimidazole of the invention has reasonable technical conditions, the used raw materials are cheap and can be obtained easily, the operation is simple and safe, the reaction conditions are mild and the production cost is low with less three wastes, thereby having higher implementation value and social and economic benefits.

Description

technical field [0001] The invention relates to a chemical synthesis method of 2-hydroxybenzimidazole. Background technique [0002] 2-Hydroxybenzimidazole is an important pharmaceutical intermediate and organic pigment intermediate, which is widely used in industry, such as the synthesis of 2-chlorobenzimidazole, a key intermediate of mizolastine. [0003] Before the present invention provides, the preparation method of 2-hydroxybenzimidazole in the prior art is to be the solvent of high boiling point, as n-amyl alcohol, DMF, ethylene glycol etc. o-phenylenediamine and urea are mixed, through a long time The 2-hydroxybenzimidazole is prepared by heating at high temperature under reflux, and the yield is medium. Due to the long-time operation at high temperature, this method has potential danger and medium yield; such as CN1944416, Przemysl Chemiczny [2004, 83 (8), 379-382] and the like. There are also reports that ethyl anthranilate and hydroxylamine are used as raw mater...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D235/26
Inventor 吴华悦吴登泽黄小波苏为科
Owner WENZHOU UNIVERSITY
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