The synthetic method of n-(2-benzimidazolyl)-methyl carbamate

A technology based on methyl carbamate and benzimidazole, applied in the field of organic synthesis, can solve the problems of serious environmental pollution, environmental pollution, complex process, etc., and achieve high yield, simple operation, and environmental friendliness

Active Publication Date: 2015-10-07
JINGBO AGROCHEM TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In this method, it is first necessary to use a large amount of alkali to neutralize the hydrogen chloride generated by the reaction, and form a sodium salt with methyl cyanamide; secondly, it is necessary to use a large amount of hydrochloric acid to acidify the sodium salt of methyl cyanamide, and neutralize And reaction produces ammonia, therefore, this method is easy to produce a large amount of acid-base waste water, pollutes the environment, and process is complicated, difficult to operate
Another commonly used method is the lime nitrogen process, which mainly uses lime nitrogen hydrolysis to produce cyanamide, directly reacts with methyl chloroformate to generate calcium salt of methyl chloroformate, and then adds o-phenylenediamine after filtration and acidification The reaction product, this process is easy to cause a large amount of industrial waste residue, which is very difficult to handle and seriously pollutes the environment

Method used

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  • The synthetic method of n-(2-benzimidazolyl)-methyl carbamate

Examples

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Effect test

Embodiment 1

[0022] A kind of synthetic method of N-(2-benzimidazolyl)-methyl carbamate, its specific steps are:

[0023] (1) Add 11.5g of methyl chloroformate and 16.4g of 50% sodium phosphate solution to 21.0g of 30% cyanamide aqueous solution at the same time. During the dropping process, control the reaction pH value to 7.0, and control the reaction temperature at 5°C. After finishing, heat preservation reaction 2 hours;

[0024] (2) Raise the temperature of the above reaction solution to 95°C, and put 10.8g of o-phenylenediamine into it, keep it warm for 3 hours, heat filter after the reaction, and wash with 80°C water to obtain 17.3g of the product. The obtained product was detected by high performance liquid chromatography (methanol:water=60:40, wavelength 230nm chromatographic column 20RBAX SB-C184.6*150mm5μm, flow rate 1.0ml / min column temperature 30°C). Yield 90.6%, content 98.0%.

Embodiment 2

[0026] A kind of synthetic method of N-(2-benzimidazolyl)-methyl carbamate, its specific steps are:

[0027] (1) Add 14.2g of methyl chloroformate and 11.2g of 50% potassium carbonate aqueous solution to 12.8g of 40% cyanamide aqueous solution at the same time. During the dropping process, control the reaction pH value to 7.2, and control the reaction temperature at 10°C. After finishing, heat preservation reaction 2.3 hours;

[0028] (2) Raise the temperature of the above reaction solution to 93°C, and put 10.8g of o-phenylenediamine into it, keep it warm for 3.5 hours, heat filter after the reaction, and wash with 84°C water to obtain 17.1g of the product. The obtained product was detected by high performance liquid chromatography (methanol:water=60:40, wavelength 230nm chromatographic column 20RBAX SB-C184.6*150mm5μm, flow rate 1.0ml / min column temperature 30°C). Yield 89.5%, content 98.1%.

Embodiment 3

[0030] A kind of synthetic method of N-(2-benzimidazolyl)-methyl carbamate, its specific steps are:

[0031] (1) Add 14.2g of methyl chloroformate and 11.4g of 50% sodium phosphate solution to 14.0g of 30% cyanamide aqueous solution at the same time. During the dropping process, control the reaction pH value to 7.4, and control the reaction temperature at 8°C. After finishing, heat preservation reaction 2.4 hours;

[0032] (2) Raise the temperature of the above reaction solution to 91°C, add 10.8g of o-phenylenediamine into it, keep it warm for 3.2 hours, heat filter after the reaction, and wash with 82°C water to obtain 17.2g of the product. The obtained product was detected by high performance liquid chromatography (methanol:water=60:40, wavelength 230nm chromatographic column 20RBAX SB-C184.6*150mm5μm, flow rate 1.0ml / min column temperature 30°C). Yield 90.3%, content 98.1%.

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Abstract

The invention discloses a synthetic method of N-(2-benzimidazolyl)-methyl carbamate. The method comprises the steps of by taking hydrogen cyanamide, methylclhlorofonmate and o-phenylenediamine as materials, adding strong alkali and weak acid salt in synthetic process; adding the strong alkali and weak acid salt to control the pH value of a reaction system in the reaction process, achieving the target of feeding once to control the pH of two-step reaction by the buffer effect, wherein the strong alkali and weak acid salt can be combined with and consume hydrogen chloride generated in the first step of reaction to counteract ammonia generated in the second step of reaction. The synthetic method is simple to operate, high in yield, and environment-friendly; the cost of acid-base is reduced; generation of impurities in reaction is reduced; and no waste water or residue is generated.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a method for synthesizing the pesticide carbendazim-N-(2-benzimidazolyl)-methyl carbamate. Background technique [0002] Carbendazim, also known as cotton wilt, benzimidazole No. 44, is a benzimidazole fungicide, scientific name N-(2-benzimidazolyl)-methyl carbamate, referred to as MBC, is a broad Spectrum fungicides have control effects on a variety of crop diseases caused by fungi (such as Deuteromycetes, Polyascus). The appearance of its pure product is white crystal, the original drug is brown powder, and its chemical properties are stable. The active ingredient of the original drug will not change after 2-3 years of storage in a cool and dry place, and has low toxicity to humans, livestock and fish. [0003] At present, there are mainly two methods for domestically producing synthetic carbendazim. One is to first synthesize methyl cyanamide formate wi...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D235/32
Inventor 王越先李洪侠栾波吴文雷魏政
Owner JINGBO AGROCHEM TECH CO LTD
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