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Preparation method of paracyano-group phenyl hydrazine hydrochloride

A technology of cyanophenylhydrazine and hydrochloride, which is applied in the field of preparation of aromatic hydrazine hydrochloride synthesis, can solve problems such as low yield and poor crystal form, achieve short production time, low requirements for production equipment, The effect of high overall yield

Inactive Publication Date: 2009-10-07
上海药明康德新药开发有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a synthetic method for effectively preparing p-cyanophenylhydrazine hydrochloride, which mainly solves the technical problems of poor crystal form and low yield in existing preparation methods

Method used

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  • Preparation method of paracyano-group phenyl hydrazine hydrochloride

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] Synthesis of p-cyanophenylhydrazine hydrochloride

[0013] Under mechanical stirring, (1kg, 8.5mol) p-cyanoaniline was dissolved in a 20-liter reactor of water (2.4L) and hydrochloric acid (3.1L), cooled to 5-10°C with an ice bath, and the reaction solution became White suspension. Slowly add sodium nitrite aqueous solution (602g / 5L) dropwise, and control the internal temperature at -5-5°C during the dropwise addition. After the dropwise addition, it can be observed that the reaction solution turns into a clear and transparent solution. After stirring for half an hour at -5-5°C, add SnCl dropwise to the clear solution 2 .2H 2 O (3.87kg, 16.9mol) of hydrochloric acid solution (35-37% HCl, 4.2L), the internal temperature is controlled at 5-10°C during the dropwise addition. The dropwise addition process was accompanied by heat release, and white solids were gradually precipitated. Stir at 5-10°C for 1 hour and filter. The filter cake was washed with 35-37% hydroch...

Embodiment 2

[0017] Synthesis of p-cyanophenylhydrazine hydrochloride

[0018] Under mechanical stirring, (1kg, 8.5mol) p-cyanoaniline was dissolved in a 20-liter reactor of water (2.4L) and hydrochloric acid (3.1L), cooled to 5-10°C with an ice bath, and the reaction solution became White suspension. Slowly add sodium nitrite aqueous solution (602g / 5L) dropwise, and control the internal temperature at -5-5°C during the dropwise addition. After the dropwise addition, it can be observed that the reaction solution turns into a clear and transparent solution. After stirring for half an hour at -5-5°C, add SnCl dropwise to the clear liquid 2 .2H 2 O (3.87kg, 16.9mol) of hydrochloric acid solution (35-37% HCl, 4.2L), the internal temperature is controlled at 5-10°C during the dropwise addition. The dropwise addition process was accompanied by heat release, and white solids were gradually precipitated. Stir at -5-5°C for 1 hour and filter. The filter cake was washed with 35-37% hydrochlo...

Embodiment 3

[0022] Synthesis of p-cyanophenylhydrazine hydrochloride

[0023] Under mechanical stirring, (1kg, 8.5mol) p-cyanoaniline was dissolved in a 20-liter reactor of water (2.4L) and hydrochloric acid (3.1L), cooled to 5-10°C with an ice bath, and the reaction solution became White suspension. Slowly add sodium nitrite aqueous solution (602g / 5L) dropwise, and control the internal temperature at -5-5°C during the dropwise addition. After the dropwise addition, it can be observed that the reaction solution turns into a clear and transparent solution. After stirring at 5-10°C for half an hour, add SnCl dropwise to the clear solution 2 .2H 2 O (3.87kg, 16.9mol) of hydrochloric acid solution (35-37% HCl, 4.2L), the internal temperature is controlled at 5-10°C during the dropwise addition. The dropwise addition process was accompanied by heat release, and white solids were gradually precipitated. Stir at -5-5°C for 1 hour and filter. The filter cake was washed with 35-37% hydroch...

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Abstract

The invention relates to a preparation method for compounding fragrant hydrazine, in particular to a preparation method of paracyano-group phenyl hydrazine hydrochloride, which mainly solves the technical problems of poor crystal shape and low yield of the prior preparation method. The adopted technical scheme is as follows: the preparation method of the paracyano-group phenyl hydrazine hydrochloride is characterized in that: paracyano-group aniline is used as a raw material and is prepared into diazo hydrochloride in a hydrochloric water solution by the diazotizing reaction of sodium nitrite in the mode of one-step continuous reacting operation, the diazo hydrochloride is reduced by a tin-protochloride hydrochloric solution, filtered and washed to obtain paracyano-group phenyl hydrazine hydrochloride, and the paracyano-group phenyl hydrazine hydrochloride is recrystallized by the mixed solution of methanol and water to obtain a white crystal target product. The paracyano-group phenyl hydrazine hydrochloride obtained by the invention is an important normal medical intermediate product.

Description

Technical field: [0001] The invention particularly relates to a preparation method for the synthesis of aromatic hydrazine hydrochloride, in particular to a preparation method for p-cyanophenylhydrazine hydrochloride. Background technique: [0002] P-cyanophenylhydrazine is a relatively important commonly used drug intermediate. For the preparation of p-cyanophenylhydrazine, the literature reports also use p-cyanoaniline as a raw material, which is obtained by reacting with sodium nitrite and tin dichloride / concentrated hydrochloric acid successively. p-Cyanophenylhydrazine as the hydrochloride salt. But what obtain is white powder, and yield is only 70%. Therefore, find a kind of suitable solvent to carry out recrystallization, obtain good crystal form, improve product yield and just become the key problem that the present invention needs to solve. Invention content: [0003] The purpose of the present invention is to provide a synthetic method for effectively preparing...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C243/22C07C241/02
Inventor 游先军黄平周盛峰郭劲松顾虹唐苏翰李革
Owner 上海药明康德新药开发有限公司
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