Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

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
View PDF6 Cites 9 Cited by
  • 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

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Synthetic method of N-(2-benzimidazolyl)-methyl carbamate
  • 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%.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

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

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
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
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com