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A kind of preparation method of 2-mercapto-1-methylimidazole

A technology of methylimidazole and mercapto, which is applied in the field of preparation of 2-mercapto-1-methylimidazole, can solve the problems of difficult industrial scale-up production and harsh reaction conditions, and achieve the effect of low price

Active Publication Date: 2020-06-26
浦拉司科技(上海)有限责任公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0013] The reaction conditions of this method are harsh, and n-butyllithium is added dropwise at -78°C, which is difficult for industrial scale-up production

Method used

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  • A kind of preparation method of 2-mercapto-1-methylimidazole
  • A kind of preparation method of 2-mercapto-1-methylimidazole
  • A kind of preparation method of 2-mercapto-1-methylimidazole

Examples

Experimental program
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Effect test

Embodiment 1

[0032] In the first step, add 249g of chloroacetaldehyde dimethyl acetal and 218g of water into a 1L high-pressure reactor, then pass in 218g of monomethylamine gas, start stirring, raise the temperature to 80-85°C, and react for 16 hours. GC detects that the raw material is less than ≦ 0.5%, lower the temperature and release the pressure, drop to about 20°C, add 100g of dichloromethane each time, extract 3 times, combine the organic phase, first evaporate the solvent, and then rectify under reduced pressure to obtain 202g of the product, the GC content is 96%, and the yield 85%.

[0033] In the second step, add 202g of the above product, 186g of tert-butylsulfonitrile, and 600mL of toluene into a 1L three-necked flask, start stirring, cool down to about 15°C, add 12g of boron trifluoride ether solution dropwise, and control the temperature not to exceed 25°C. After dripping, raise the temperature to 50-55°C and react for 3 hours. Evaporate the solvent under normal pressure wh...

Embodiment 2

[0036] In the first step, add 249g of chloroacetaldehyde dimethyl acetal and 84g of water into a 1L high-pressure reactor, then feed 156g of monomethylamine gas, start stirring, raise the temperature to 80-85°C, and react for 16 hours. GC detects that the raw material is less than ≦ 0.5%, lower the temperature and release the pressure, drop to about 20°C, add 100g of dichloromethane each time, extract 3 times, combine the organic phase, first evaporate the solvent, and then rectify under reduced pressure to obtain 198g of the product, the GC content is 95%, and the yield 83%.

[0037] In the second step, add 198g of the above product, 201g of tert-butylsulfonitrile, and 600mL of toluene into a 1L three-necked flask, start stirring, cool down to about 15°C, add 36g of boron trifluoride tetrahydrofuran solution dropwise, and control the temperature not to exceed 25°C. After dripping, rise to 60-70°C and react for 3 hours. Evaporate the solvent at normal pressure while raising th...

Embodiment 3

[0040] In the first step, add 249g of chloroacetaldehyde dimethyl acetal and 117g of water into a 1L high-pressure reactor, then inject 218g of monomethylamine gas, start stirring, raise the temperature to 80-85°C, and react for 16 hours. GC detects that the raw material is less than ≦ 0.5%, lower the temperature and release the pressure, drop to about 20°C, add 100g of dichloromethane each time, extract 3 times, combine the organic phase, first evaporate the solvent, and then rectify under reduced pressure to obtain 207g of the product, the GC content is 96%, and the yield 87%.

[0041] In the second step, add 207g of the above product, 200g of tert-butylsulfonitrile, and 600mL of toluene into a 1L three-necked flask, start stirring, cool down to about 15°C, add 29g of boron trifluoride acetonitrile solution dropwise, and control the temperature not to exceed 25°C. After dripping, rise to 60-70°C and react for 3 hours. Evaporate the solvent at normal pressure while raising th...

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Abstract

The invention discloses a preparation method of electronic grade 2-sulfydryl-1-methylimidazole. The method comprises the following steps: (1) a water solution of chloroacetaldehyde dimethyl acetal andmethylamine performs tank closing reaction for 16h at 80 to 85 DEG C; cooling and pressure release are performed; a solvent is used for extraction; the solvent is concentrated; rectification under vacuum is performed to obtain an intermediate of methylaminoacetaldehyde dimethyl acetal; (2) the methylaminoacetaldehyde dimethyl acetal and t-butyl thionitrile react under the boron trifluoride catalysis; condensation reaction is performed at 50 to 70 DEG C to obtain 2-tert-butyl sulfenyl-1-methylimidazole; (3) a solvent is added into the 2-tert-butyl sulfenyl-1-methylimidazole; a catalyst and anorganic solvent are added; reaction is performed at constant temperature; after filtering, filter liquid is concentrated; then, electronic grade water crystallization is performed to obtain the product of 2-sulfydryl-1-methylimidazole. The preparation method has the advantages that the raw material price is low; the environment-friendly effect is achieved; the operation of the synthesis method issimple and convenient; the product quality conforms to application standards of electronic chemicals.

Description

Technical field: [0001] The invention belongs to the field of organic chemistry, and in particular relates to a preparation method of 2-mercapto-1-methylimidazole. Background technique: [0002] 2-Mercapto-1-methylimidazole is an antithyroid drug commonly used in medicine. In recent years, it has been found that it can play an important role in liquid crystal materials, and has been concerned and researched by a large number of electronic chemical manufacturers. [0003] At present, the synthetic method of the 2-mercapto-1-methylimidazole of bibliography mainly contains two kinds: [0004] 1) The first synthetic method [0005] Using bromoacetaldehyde dimethyl acetal and methylamine aqueous solution as raw materials, through ammonolysis reaction, the intermediate methylamino acetaldehyde dimethyl acetal is obtained, and then reacted with potassium thiocyanate to obtain the target product [0006] The synthetic route is as follows: [0007] [0008] However, this synth...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D233/84
Inventor 漆伟君李静肖海旺
Owner 浦拉司科技(上海)有限责任公司