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Chemical synthesis method of 2-chlorin benzimidazole

A chlorobenzimidazole and chemical synthesis technology, applied in the direction of organic chemistry and the like, can solve the problems of high risk factor, high equipment requirements, unfriendly environment, etc., and achieve the effects of simple and safe operation, less three wastes, and low production cost

Inactive Publication Date: 2009-10-07
WENZHOU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] Before the present invention was provided, the preparation method of 2-chlorobenzimidazole in the prior art was prepared by mixing 2-hydroxybenzimidazole and phosphorus oxychloride, heating to reflux and reacting under the condition of hydrogen chloride gas, for example: CN1944416, Zhejiang University Journal (Natural Science Edition) [2003,30 (6), 671-673]; There are also reports in the literature that in the presence of phosphorus trichloride (or phosphorus pentachloride), 2-hydroxybenzimidazole and Phosphorus oxychloride mixed heating reflux makes 2-chlorobenzimidazole, as CN1486981, Synthetic Communications [1998,28 (9), 1703-1712]; A major feature of this method is to have adopted environment unfriendly reagent, to equipment The requirements are high, the risk factor is large in the production process, the three wastes are serious, and it is not friendly to the environment;

Method used

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  • Chemical synthesis method of 2-chlorin benzimidazole
  • Chemical synthesis method of 2-chlorin benzimidazole
  • Chemical synthesis method of 2-chlorin benzimidazole

Examples

Experimental program
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Embodiment 1

[0026] The amount of feeding material is 2-hydroxybenzimidazole, two (trichloromethyl) carbonate, N, N-dimethylaniline=1: 0.4: 1.0, the feeding amount of 2-hydroxybenzimidazole is 100mmol, bis The charging capacity of (trichloromethyl) carbonate is 40mmol, and the charging capacity of N, N-dimethylaniline is 100mmol, and the consumption of 1,4-dioxane as solvent is 201ml, and its volume consumption is 2-hydroxyl 15 times the mass of benzimidazole.

[0027] In a 500ml three-neck flask equipped with mechanical stirring, a constant pressure dropping funnel and a thermometer, add 13.4g 2-hydroxybenzimidazole, 136ml 1,4-dioxane and 12.6ml N,N-dimethylaniline in sequence , the temperature of the mixture was controlled at 10°C. Slowly add 65ml of 1,4-dioxane solution in which 11.0g of bis(trichloromethyl)carbonate is dissolved in the mixed solution dropwise, after the dropwise addition, continue to maintain the temperature and stir for 6h, and adjust the pH with 12% sodium hydroxide...

Embodiment 2

[0029] The amount of feeding material is 2-hydroxybenzimidazole, two (trichloromethyl) carbonate, N, N-dimethylaniline=1: 0.4: 1.0, the feeding amount of 2-hydroxybenzimidazole is 100mmol, bis The charging capacity of (trichloromethyl) carbonate is 40mmol, and the charging capacity of N, N-dimethylaniline is 100mmol, and the consumption of 1,4-dioxane as solvent is 536ml, and its volume consumption is 2-hydroxyl 40 times the mass of benzimidazole.

[0030] In a 1000ml three-necked flask equipped with mechanical stirring, a constant pressure dropping funnel and a thermometer, add 13.4g 2-hydroxybenzimidazole, 300ml 1,4-dioxane and 12.6ml N,N-dimethylaniline in sequence , the temperature of the mixture was controlled at 10°C. Slowly add 236ml of 1,4-dioxane solution in which 11.0g of bis(trichloromethyl)carbonate is dissolved in the mixed solution dropwise, continue to maintain the temperature and stir for 12h after the dropwise addition, and adjust the pH with 12% sodium hydro...

Embodiment 3

[0032] The amount of feeding material is 2-hydroxybenzimidazole, two (trichloromethyl) carbonate, N, N-diethylaniline=1: 0.4: 1.0, the feeding amount of 2-hydroxybenzimidazole is 100mmol, bis The charging capacity of (trichloromethyl) carbonate is 40mmol, and the charging capacity of N, N-diethylaniline is 100mmol, and the consumption of 1,4-dioxane as solvent is 536ml, and its volume consumption is 2-hydroxyl 40 times the mass of benzimidazole. The reaction temperature was -5°C.

[0033] The operation steps and other reaction conditions were the same as in Example 2 to obtain 12.1 g of 2-chlorobenzimidazole with a yield of 79.6% and a purity of 98.4%.

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Abstract

The invention discloses a chemical synthesis method of 2-chlorobenzimidazole, that is, 2-hydroxybenzimidazole and bis(trichloromethyl)carbonate are used as raw materials, under the action of an organic base, in an organic solvent After reacting at -30-50° C. for 0.5-12 hours, the reaction solution is post-treated, and the product is post-treated to obtain the 2-chlorobenzimidazole. The chemical synthesis method of 2-chlorobenzimidazole of the present invention has reasonable process conditions, cheap and easy-to-obtain raw materials, simple and safe operation, low production cost, less waste, and great implementation value and social and economic benefits.

Description

technical field [0001] The invention relates to a chemical synthesis method of 2-chlorobenzimidazole. Background technique [0002] 2-Chlorobenzimidazole is a widely used intermediate in organic synthesis, widely used in the synthesis of medicines, pesticides, etc., especially as an intermediate in the synthesis of a series of antihistamines, for example, for the treatment of allergic conjunctivitis, urticaria The new anti-allergic drugs Mizolastin (mizolastine), Emedastine and so on. [0003] Before the present invention was provided, the preparation method of 2-chlorobenzimidazole in the prior art was prepared by mixing 2-hydroxybenzimidazole and phosphorus oxychloride, heating to reflux and reacting under the condition of hydrogen chloride gas, for example: CN1944416, Zhejiang University Journal (Natural Science Edition) [2003,30 (6), 671-673]; There are also reports in the literature that in the presence of phosphorus trichloride (or phosphorus pentachloride), 2-hydroxy...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D235/24
Inventor 吴华悦黄小波吴登泽苏为科
Owner WENZHOU UNIV