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4-amino-3-fluorophenol and synthesizing method thereof

A synthesis method and technology of fluorophenol are applied in the field of pharmaceutical intermediate 4-amino-3-fluorophenol and its synthesis, which can solve the problems of few preparation methods, incapable of industrialized production, harsh reaction conditions, etc. Effects of protection, yield improvement, and reaction efficiency improvement

Inactive Publication Date: 2016-07-27
叶芳
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] 4-Amino-3-fluorophenol is an important intermediate of the pesticide flubenzuron, and is also an important intermediate in the preparation of medicine and chemical industry. There are few reports on its preparation method
This process solves the problem of platinum carbon recovery and application, but cannot be industrialized due to the use of porous extractors
[0003] Chinese patent (200310120860.0) discloses a method for preparing 4-amino-3-fluorophenol by hydrogenation of o-fluoronitrobenzene. The reaction is carried out in an autoclave filled with an acidic medium, and a platinum / carbon catalyst is used to catalyze The hydrogenation product is extracted and separated, distilled, filtered, and dried to obtain the finished product. The 4-amino-3-fluorophenol prepared by this method has high purity, but the reaction conditions are harsh and the equipment requirements are high

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] (1) Mix 2.5 mol of m-fluoroaniline and 1 mol of sodium nitrite, stir in an ice-salt bath for 1 hour, then add 0.8 mol of sodium fluoroborate dropwise, continue stirring for 1 hour, add 6 mol of urea, stir for 20 minutes, filter, and dry to obtain white Diazonium salt solid;

[0022] (2) Mix the white diazonium salt solid obtained in step (1) with anhydrous copper sulfate, deionized water, and concentrated sulfuric acid, heat to 100° C., and distill the distillate with dichloromethane, then Dry and concentrate to obtain m-fluorophenol;

[0023] (3) Mix m-fluorophenol and ionic liquid obtained in step (2), stir in an ice-salt bath for 10 minutes, then add concentrated nitric acid, continue stirring for 20 minutes, add water to dilute, heat up to 8-10°C, and then steam Distillation, after distillation, extract the remaining liquid with ether, collect the ether layer, and wash with saturated sodium chloride, add the ether layer into sodium carbonate solution, stir to obtai...

Embodiment 2

[0026] (1) Mix 3 mol of m-fluoroaniline and 1 mol of sodium nitrite, stir in an ice-salt bath for 2 hours, then add 1.5 mol of sodium fluoroborate dropwise, continue stirring for 2 hours, add 10 mol of urea, stir for 50 minutes, filter, and dry to obtain a white heavy Nitrogen salt solid;

[0027] (2) Mix the white diazonium salt solid obtained in step (1) with anhydrous copper sulfate, deionized water, and concentrated sulfuric acid, heat to 120° C., and distill the distillate with dichloromethane, then Dry and concentrate to obtain m-fluorophenol;

[0028] (3) Mix m-fluorophenol and ionic liquid obtained in step (2), stir in ice-salt bath for 20 minutes, then add concentrated nitric acid, continue stirring for 40 minutes, add water to dilute, heat up to 8-10°C, and then steam Distillation, after distillation, extract the remaining liquid with ether, collect the ether layer, and wash with saturated sodium chloride, add the ether layer into sodium carbonate solution, stir to ...

Embodiment 3

[0031] (1) Mix 2.6 mol of m-fluoroaniline and 1 mol of sodium nitrite, stir in an ice-salt bath for 1.2 h, then add 0.9 mol of sodium fluoroborate dropwise, continue stirring for 1.2 h, add 7 mol of urea, stir for 25 min, filter, and dry. A white diazonium salt solid was obtained;

[0032] (2) Mix the white diazonium salt solid obtained in step (1) with anhydrous copper sulfate, deionized water, and concentrated sulfuric acid, heat to 105° C., and distill the distillate with dichloromethane, then Dry and concentrate to obtain m-fluorophenol;

[0033] (3) Mix m-fluorophenol and ionic liquid obtained in step (2), stir in an ice-salt bath for 15 minutes, then add concentrated nitric acid, continue stirring for 30 minutes, add water to dilute, heat up to 8-10°C, and then steam Distillation, after distillation, extract the remaining liquid with ether, collect the ether layer, and wash with saturated sodium chloride, add the ether layer into sodium carbonate solution, stir to obtai...

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Abstract

The invention discloses 4-amino-3-fluorophenol and a synthesizing method thereof.The synthesizing method comprises the steps that fluoroaniline serves as a raw material, a diazo-reaction is carried out first, then a fluorine resolving reaction is carried out, and a white diazonium salt solid is obtained; then, the white diazonium salt solid is subjected to a hydrolysis reaction, and 3-fluorophenol is obtained; 3-fluorophenol is then subjected to a nitration reaction, and 3-fluorine-4-nitrophenol is obtained; then, obtained 3-fluorine-4-nitrophenol is reduced, and 4-amino-3-fluorophenol is obtained.According to 4-amino-3-fluorophenol and the synthesizing method thereof, ionic liquid serves as a reaction solvent, the volatility is low, environment is easily protected, and no harm is caused to the human body; in the reaction of reducing nitro groups into amino groups, the microwave heating mode is adopted, so that the reaction efficiency is greatly improved, and the product yield is increased.

Description

Technical field: [0001] The invention relates to the technical field of biomedicine, in particular to a pharmaceutical intermediate 4-amino-3-fluorophenol and a synthesis method thereof. Background technique: [0002] 4-Amino-3-fluorophenol is an important intermediate of the pesticide and insecticide fiflubenzuron, and is also an important intermediate in the preparation of medicine and chemical industry. There are few reports on its preparation method. American scholars Benner, Brown et al., Derrenbacker et al., and Japanese scholars Tanaka et al., Xia Ben et al. respectively used platinum carbon catalysis to perform reductive rearrangement to obtain 4-amino-3-fluorophenol. Because this process is easy to cause platinum carbon poisoning, it cannot be applied mechanically, resulting in high production costs. Klausener et al. used o-fluoronitrobenzene and sulfuric acid aqueous solution as raw materials, catalyzed by platinum carbon, and reacted under pressure with hydrogen,...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C213/02C07C215/76
CPCC07C37/045C07C201/08C07C213/02C07C215/76C07C245/20C07C39/27C07C205/26Y02P20/54
Inventor 叶芳
Owner 叶芳
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