Synthesis method of p-chlorophenyl hydrazine

A technology for p-chlorophenylhydrazine and a synthesis method, which is applied in the directions of hydrazine, hydrazine preparation, nitrogen and non-metallic compounds, etc., can solve the problems of troublesome recycling and processing, a large amount of waste water, and high requirements for operation and feeding, so as to reduce the consumption of water, The effect of reducing emissions and improving safety

Inactive Publication Date: 2017-01-04
ANHUI COSTAR BIOCHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Yet above-mentioned several reducing agents all have some defects: 1) the method cost of preparing p-chlorophenylhydrazine with tin dichloride as reduction diazonium liquid is higher, and yield is lower, and reaction can produce a large amount of waste water, recycling and processing Both are troublesome; 2) When sodium sulfite is used as reducing agent, due to the low solubility

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0018] Example 1

[0019] Add 78.2g of hydrazine hydrate with a mass concentration of 80% into a 250ml four-necked flask with a stirring and reflux condenser, turn on the stirring, cool to 0℃ with an ice salt bath, and start to add 61.8g of hydrochloric acid with a mass concentration of 36%. , Obtain the hydrazine hydrochloride solution, store it at low temperature, add 64g p-chloroaniline and 90ml ethylene glycol into a 500ml four-necked flask, turn on the stirring, heat up to 100℃, add the hydrazine hydrochloride solution dropwise with a constant pressure dropping funnel, keep warm and reflux for reaction 5h, cool to room temperature, add water and stir to precipitate a solid, filter, wash with water, and dry to obtain p-chlorophenylhydrazine. The solid is dried 60.5g, the yield is 85%, and the purity is 98.9%.

Example Embodiment

[0020] Example 2

[0021] Add 78.2g of hydrazine hydrate with a mass concentration of 80% to a 250ml four-necked flask with a stirring and reflux condenser, turn on the stirring, cool to 5℃ with an ice salt bath, and start to add 61.8g of hydrochloric acid with a mass concentration of 36%. , Obtain the hydrazine hydrochloride solution, store it in low-temperature refrigeration, add 64g p-chloroaniline and 90ml ethylene glycol into a 500ml four-necked flask, turn on the stirring, heat up to 110℃, add the hydrazine hydrochloride solution dropwise with a constant pressure dropping funnel, keep warm and reflux for reaction 5h, cool to room temperature, add water and stir to precipitate a solid, filter, wash with water, and dry to obtain p-chlorophenylhydrazine. The solid is dried 65.5g, the yield is 92%, and the purity is 99.2%.

Example Embodiment

[0022] Example 3

[0023] Add 78.2g of hydrazine hydrate with a mass concentration of 80% to a 250ml four-necked flask with a stirring and reflux condenser, turn on the stirring, cool to 4℃ with an ice salt bath, and start adding 61.8g of hydrochloric acid with a mass concentration of 36% dropwise , Obtain the hydrazine hydrochloride solution, store it in low-temperature refrigeration, add 64g p-chloroaniline and 90ml ethylene glycol into a 500ml four-necked flask, turn on the stirring, heat up to 120℃, add the hydrazine hydrochloride solution dropwise with a constant pressure dropping funnel, keep warm and reflux for reaction 5h, cool to room temperature, add water and stir to separate out a solid, filter, wash with water, and dry to obtain p-chlorophenylhydrazine. The solid is dried 62.0g, the yield is 87%, and the purity is 98.2%.

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Abstract

The invention discloses a synthesis method of p-chlorophenyl hydrazine. The method comprises the following steps: (1) adding hydrazine hydrate into a four-neck flask, starting to stir and adding a hydrochloric acid solution dropwise at a certain reaction temperature to obtain a hydrazine hydrochloride solution; (2) adding p-chloroaniline into the four-neck flask, starting to stir by using glycol as a solvent, adding the hydrazine hydrochloride solution obtained in the step (1) dropwise at the reaction temperature of 100 to 120 DEG C, performing heat-insulating reflux reaction for 2 to 6 hours, and filtering, washing and drying after the reaction is finished to obtain the p-chlorophenyl hydrazine. By the method, one-step synthesis of the p-chlorophenyl hydrazine is realized by using the p-chloroaniline and the hydrazine hydrate, the yield can reach more than 85%, and the method is suitable for enterprise large-scale production; by the method provided by the invention, the tedious operation steps, such as diazotization, reduction and acidolysis, in the traditional method are avoided, and the process safety is improved; by the method, the use amount of water can be reduced, the discharge quantity of waste water is greatly reduced, waste water treatment in the later period is avoided, and the cost is reduced.

Description

technical field [0001] The invention belongs to the fields of organic synthesis and pesticide synthesis, and in particular relates to a synthesis method of p-chlorophenylhydrazine. Background technique [0002] p-Chlorophenylhydrazine is a widely used organic synthesis intermediate, which can be used in the synthesis of dyes, medicines and other chemicals. At present, the synthesis method of p-chlorophenylhydrazine mainly uses p-chloroaniline as raw material, carries out diazotization reaction with sodium nitrite and hydrochloric acid at 0-5°C, and uses tin dichloride, sodium sulfite, sodium bisulfite, ammonium sulfite etc. as a reducing agent for the reduction reaction, and finally for the hydrolysis reaction to obtain p-chlorophenylhydrazine. [0003] Yet above-mentioned several reducing agents all have some defects: 1) the method cost of preparing p-chlorophenylhydrazine with tin dichloride as reduction diazonium liquid is higher, and yield is lower, and reaction can pro...

Claims

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Application Information

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IPC IPC(8): C07C241/02C07C243/22
CPCC01B21/16C07C241/02C07C243/22
Inventor 王红伟赵维德黄会真王小生李箕明张涛
Owner ANHUI COSTAR BIOCHEM CO LTD
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