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P-chlorophenylu hydrazine hydrochloride preparation method

A technology of chlorophenylhydrazine hydrochloride and p-chloroaniline is applied in the field of preparation of p-chlorophenylhydrazine hydrochloride, can solve the problems of high cost, low product yield, and is difficult to realize industrialization, and achieves reduction of environmental protection pressure, High yield and purity, reducing the effect of filtration times

Inactive Publication Date: 2015-09-23
HUNAN HAILI CHEM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The product yield is low, resulting in high cost, and it is difficult to realize industrialization

Method used

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  • P-chlorophenylu hydrazine hydrochloride preparation method
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  • P-chlorophenylu hydrazine hydrochloride preparation method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Add 61.2g of 36% hydrochloric acid, 28.0g of water, and 25.7g (0.2mol) of p-chloroaniline into a 500mL three-necked flask equipped with mechanical stirring, a thermometer and a reflux device, slowly cool to 5°C under stirring, and drop in 14.1 g sodium nitrite and 28.0 g water solution, after stirring for 1 h, the diazonium salt was obtained for later use.

[0018] In another 500mL three-necked flask equipped with mechanical stirring, thermometer and reflux device, add 63.0g sodium sulfite and 80.0g water, raise the temperature to 70°C, slowly add the above diazonium salt, keep warm at 70°C for 3h, heat filter, and the filtrate Add 51.4g of dichloroethane for extraction, separate the organic phase, slowly add hydrochloric acid (94.7g of 36% hydrochloric acid, 80.0g of water) to the aqueous phase at 70°C, keep warm for 1h, cool to room temperature, filter, and dry 31.4 g of p-chlorophenylhydrazine hydrochloride was obtained, with a purity of 99.6%, and a yield of 87.4% b...

Embodiment 2

[0020] Add 61.2g of 36% hydrochloric acid, 28.0g of water, and 25.7g (0.2mol) of p-chloroaniline into a 500mL three-necked flask equipped with mechanical stirring, a thermometer and a reflux device, slowly cool to 5°C under stirring, and drop in 14.1 g sodium nitrite and 28.0 g water solution, after stirring for 1 h, the diazonium salt was obtained for later use.

[0021] In another 500mL three-necked flask equipped with mechanical stirring, thermometer and reflux device, add 63.0g sodium sulfite and 80.0g water, raise the temperature to 70°C, slowly add the above diazonium salt, keep warm at 70°C for 3h, heat filter, and the filtrate Add 128.5g of benzene for extraction, separate the organic phase, and slowly add hydrochloric acid (94.7g of 36% hydrochloric acid, 80.0g of water) to the water phase at 70°C, keep warm for 1h, cool to room temperature, filter, and dry to obtain 31.2g p-Chlorophenylhydrazine hydrochloride, the purity is 99.7%, and the yield is 86.9% based on p-ch...

Embodiment 3

[0023] Add 61.2g of 36% hydrochloric acid, 28.0g of water, and 25.7g (0.2mol) of p-chloroaniline into a 500mL three-necked flask equipped with mechanical stirring, a thermometer and a reflux device, slowly cool to 5°C under stirring, and drop in 14.1 g sodium nitrite and 28.0 g water solution, after stirring for 1 h, the diazonium salt was obtained for later use.

[0024] In another 500mL three-necked flask equipped with mechanical stirring, thermometer and reflux device, add 63.0g sodium sulfite and 80.0g water, raise the temperature to 70°C, slowly add the above diazonium salt, keep warm at 70°C for 3h, heat filter, and the filtrate Add 102.8g of toluene for extraction, separate the organic phase, slowly add hydrochloric acid (94.7g of 36% hydrochloric acid, 80.0g of water) to the water phase at 70°C, keep warm for 1h, cool to room temperature, filter, and dry to obtain 31.5g p-Chlorophenylhydrazine hydrochloride, the purity is 99.5%, and the yield is 87.5% based on p-chloro...

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Abstract

The invention discloses a p-chlorophenylu hydrazine hydrochloride preparation method. P-chloroaniline serves as a raw material, after diazotization and reduction, non-polar solvent toluene or benzene, dichloromethane, trichloromethane and dichloroethane are used for extracting an aqueous phase to remove impurities, and then hydrochloric acid is added into the aqueous phase for hydrolysis to obtain p-chlorophenylu hydrazine hydrochloride through cooling, filtering and during. The chemical equation is shown as the following (please see the formula in the specification). Compared with the prior art, the non-polar solvents are used for extraction and impurity removal, the yield and the purity of an obtained product are high, the purity of the p-chlorophenylu hydrazine hydrochloride is larger than 99%, the yield is larger than 86%, filtering only needs to be carried out once, and operation is easy. Waste water amount is reduced by half compared with the prior art, and environmental protection pressure is reduced.

Description

technical field [0001] The invention relates to a preparation method of p-chlorophenylhydrazine hydrochloride. Background technique [0002] p-Chlorophenylhydrazine hydrochloride is an important pharmaceutical and pesticide intermediate. The structural formula of the compound is as follows: [0003] [0004] The preparation methods of p-chlorophenylhydrazine hydrochloride reported in literature at home and abroad have the following several. [0005] 1. The synthesis process of p-chlorophenylhydrazine hydrochloride in the literature [J]. Applied Chemistry, 2001, 18(12): 1001-1003. It is reported that p-chloroaniline is used as raw material, and obtained by filtration after diazotization, reduction and hydrolysis The crude product of p-chlorophenylhydrazine hydrochloride, add water and sodium hydroxide to adjust the pH value and filter to obtain p-chlorophenylhydrazine, then add water and hydrochloric acid to adjust the pH value and filter to obtain p-chlorophenylhydrazine...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C243/22C07C241/02
Inventor 罗亮明胡志彬黄超群杜升华熊莉莉
Owner HUNAN HAILI CHEM IND
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