Synthetic method of N-(2-benzimidazolyl)-methyl carbamate

A technology of methyl carbamate and benzimidazolyl, applied in the field of organic synthesis, can solve the problems of serious environmental pollution, difficult operation, polluted environment and the like, and achieves the effects of high yield, simple operation and environmental friendliness

Active Publication Date: 2013-04-24
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 complicat

Method used

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  • Synthetic method of N-(2-benzimidazolyl)-methyl carbamate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] A kind of synthetic method of N-(2-benzimidazolyl)-carbamic acid methyl ester, its concrete steps are:

[0023] (1) 11.5g of methyl chloroformate and 16.4g of 50% sodium phosphate aqueous solution were added dropwise to 21.0g of 30% cyanamide aqueous solution at the same time. During the dropwise addition, the pH value of the reaction was controlled to be 7.0, and the reaction temperature was controlled at 5°C. After completion, the reaction was incubated for 2 hours;

[0024] (2) The above reaction solution was heated to 95°C, 10.8 g of o-phenylenediamine was put into it, and the reaction was kept for 3 hours. 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℃). The yield is 90.6%, and the content is 98.0%.

Embodiment 2

[0026] A kind of synthetic method of N-(2-benzimidazolyl)-carbamic acid methyl ester, its concrete steps are:

[0027] (1) 14.2g of methyl chloroformate and 11.2g of 50% potassium carbonate aqueous solution were added dropwise to 12.8g of 40% cyanamide aqueous solution. During the dropwise addition, the pH value of the reaction was controlled to be 7.2, and the reaction temperature was controlled at 10°C. After completion, the insulation reaction was carried out for 2.3 hours;

[0028] (2) The above reaction solution was heated to 93°C, 10.8g of o-phenylenediamine was put into it, and the reaction was incubated for 3.5 hours. 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℃). The yield is 89.5%, and the content is 98.1%.

Embodiment 3

[0030] A kind of synthetic method of N-(2-benzimidazolyl)-carbamic acid methyl ester, its concrete steps are:

[0031] (1) 14.2g of methyl chloroformate and 11.4g of 50% sodium phosphate aqueous solution were added dropwise to 14.0g of 30% cyanamide aqueous solution respectively. During the dropwise addition, the pH value of the reaction was controlled to be 7.4, and the reaction temperature was controlled at 8°C. After completion, the insulation reaction was carried out for 2.4 hours;

[0032] (2) The above reaction solution was heated to 91°C, 10.8g of o-phenylenediamine was put into it, and the reaction was kept for 3.2 hours. 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℃). The yield is 90.3%, and the content is 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, in particular to a method for synthesizing the pesticide carbendazim-N-(2-benzimidazolyl)-carbamic acid methyl ester. Background technique [0002] Carbendazim, also known as Mianweiling, Benzimidazole No. 44, is a benzimidazole fungicide, scientific name N-(2-benzimidazolyl)-methyl carbamate, MBC for short, is a broad-spectrum fungicide. It is a spectrum fungicide, which has a control effect on diseases caused by fungi (such as Deuteromyces spp. The pure product is white crystal in appearance, the original drug is brown powder, and the chemical properties are stable. The original drug is stored in a cool, dry place for 2-3 years. The active ingredients remain unchanged, and it is low in toxicity to humans, animals and fish. [0003] At present, there are two main methods for domestic production of synthetic carbendazim. One is to first synthesize methyl cyanamide formate with cyanami...

Claims

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Application Information

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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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