Method for preparing 3-fluorine phenylhydrazine

A technology of fluorophenylhydrazine and fluoroaniline, applied in the field of preparation of 3-fluorophenylhydrazine, can solve the problems of high production cost, long reaction time and the like, and achieve the effects of low production cost, shortened reaction time and high product purity

Inactive Publication Date: 2008-04-09
太仓市华联化工实业有限公司
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  • Application Information

AI Technical Summary

Problems solved by technology

[0002] 3-fluorophenylhydrazine is an important intermediate, especially a pharmaceutical intermediate. The prior art uses 3-fluoroaniline as a raw material, undergoes diazotization reaction, sodium sulfite reduction, and hydrolysis to prepare 3-fluorophenylhydrazine The synthetic method of hydrazine, reaction time is long, generally needs yield to be only 63-72%, and production cost is high

Method used

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Examples

Experimental program
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Embodiment Construction

[0009] The specific embodiment of the present invention is described below:

[0010] Add 100ml of water to a 600ml beaker, stir, add 57.5ml of 10N hydrochloric acid, 22.2 grams of 3-fluoroaniline, cool the solution to 0°C and slowly add sodium nitrite solution (made of 15 grams of sodium nitrite and 30ml of water), After the addition is complete, adjust the pH of the system to 1-2, control the temperature of the reaction system at 5°C, and stop the reaction after 15 minutes of reaction, filter and retain the filtrate.

[0011] Add 250ml of water into a 1000ml beaker, add 64 grams of sodium metabisulfite and 65 grams of sodium hydroxide under stirring. At this time, the pH of the solution is 7, and the temperature of the solution is 35°C. After the solution is cooled to 10°C, slowly add the above filtrate, When the addition is complete, the solution temperature is 18-20°C, pH is 7, continue to react for 30 minutes, heat the reaction system to 40-50°C, add 115ml of hydrochloric ...

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Abstract

The invention relates to a preparative method of 3-fluorophenylhydrazine. The 3-fluoroaniline is used as the primary row material, after the diazotization reaction, the reduction reaction and hydrolysis, the preparative method produces the 3-fluorophenylhydrazine, wherein, the reduction reaction adopting the sodium metabisulfite as the reducing agent is carried out in the conditions that the temperature is 10 to 35 DEG C, and the PH valve is 7 to 9. The 3-fluorophenylhydrazine prepared by the preparative method disclosed in the invention is characterized in high product purity and low production cost.

Description

technical field [0001] The invention relates to a preparation method of 3-fluorophenylhydrazine. Background technique [0002] 3-fluorophenylhydrazine is an important intermediate, especially a pharmaceutical intermediate. The prior art uses 3-fluoroaniline as a raw material, undergoes diazotization reaction, sodium sulfite reduction, and hydrolysis to prepare 3-fluorophenylhydrazine The synthetic method of hydrazine has a long reaction time, generally requires a yield of only 63-72%, and the production cost is high. Contents of the invention [0003] The technical problem to be solved by the present invention is to provide a preparation method of 3-fluorophenylhydrazine, the 3-fluorophenylhydrazine product obtained by the method has high purity and low production cost. [0004] In order to solve the above technical problems, the present invention adopts the following technical solutions: [0005] A preparation method of 3-fluorophenylhydrazine, using 3-fluoroaniline as ...

Claims

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Application Information

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IPC IPC(8): C07C243/22C07C241/02
Inventor沈云汉郁金龙
Owner太仓市华联化工实业有限公司