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Synthetic method of acetamidophenol serving as medical intermediate

A technology of acetaminophen and a synthesis method, which is applied in the field of synthesis of a pharmaceutical intermediate o-acetaminophen, can solve the problems of complicated process and low final yield, and can reduce intermediate links, shorten reaction time, and improve reaction yield. Effect

Inactive Publication Date: 2017-05-10
CHENGDU ZHONGHENG HUATIE TECH CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, most of the existing synthetic methods are complicated in process, and the final yield is not very high. Therefore, it is necessary to propose a new synthetic method, which is useful for further improving the quality and yield of the product and reducing the content of by-products. important economic significance

Method used

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  • Synthetic method of acetamidophenol serving as medical intermediate

Examples

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example 1

[0011] Mix 3 mol of o-aminophenol with 12 L of 30% formic acid solution, control the stirring speed at 130 rpm, add 4 mol of formic acetic anhydride and mix evenly, raise the temperature of the solution to 70 ° C, reflux for 90 min, and distill under reduced pressure for 3 h, pour the remaining solution into mass The fraction is 15% potassium chloride solution, the temperature of the solution is lowered to 10°C, and precipitates are precipitated, the mass fraction is 85% ether solution, the mass fraction is 90% acetone solution, recrystallization, and anhydrous calcium sulfate dehydrating agent dehydrates to obtain crystals O-acetaminophen 403.17g, yield 89%.

example 2

[0013] Mix 3mol of o-aminophenol with 13L of 35% formic acid solution, control the stirring speed at 140rpm, add 4.5mol of formic acetic anhydride and mix well, raise the solution temperature to 75°C, reflux for 100min, distill under reduced pressure for 4h, and pour the remaining solution into The mass fraction is 17% potassium chloride solution, the temperature of the solution is lowered to 13°C, and precipitates are precipitated, the mass fraction is 87% ether solution, the mass fraction is 93% recrystallized in acetone solution, and the anhydrous potassium carbonate dehydrating agent is dehydrated to obtain Crystal o-acetaminophen 416.76g, yield 92%.

example 3

[0015] Mix 3 mol of o-aminophenol with 15 L of formic acid solution with a mass fraction of 40%, control the stirring speed at 160 rpm, add 5 mol of formic acetic anhydride and mix well, raise the temperature of the solution to 80°C, reflux for 110 min, and distill under reduced pressure for 5 h, pour the remaining solution into mass The fraction is 20% potassium chloride solution, the temperature of the solution is lowered to 15°C, precipitates are precipitated, the mass fraction is 90% ether solution, the mass fraction is 96% recrystallized in acetone solution, and anhydrous calcium sulfate dehydrating agent is dehydrated to obtain crystals o-Acetaminophen 430.35g, yield 95%.

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Abstract

The invention discloses a synthetic method of acetamidophenol serving as a medical intermediate. The synthetic method comprises the following steps: mixing 3mol of o-aminophenol with 12 to 15L of formate solution; controlling the stirring speed at 130 to 160rpm, adding 4 to 5mol of acetic formic anhydride and uniformly mixing; raising the temperature of the solution to be 70 to 80DEG C, and carrying out refluxing for 90 to 110 minutes and reduced pressure distillation for 3 to 5 hours; pouring obtained residual solution into a potassium chloride solution, reducing the temperature of the solution to be 10 to 15DEG C, and separating out precipitation; washing with a diethyl ether solution, recrystallizing in an acetone solution, and dehydrating by a dehydrating agent to obtain a crystal acetamidophenol, wherein in the steps, the mass percent of the formate solution is 30 to 40 percent, the mass percent of the potassium chloride solution is 15 to 20 percent, and the mass percent of the diethyl ether solution is 85 to 90 percent.

Description

technical field [0001] The invention relates to a method for synthesizing a drug intermediate o-acetaminophen. Background technique [0002] O-acetaminophen is mainly used in organic synthesis, pharmaceutical industry, and also as a stabilizer for hydrogen peroxide. Most of the existing o-acetaminophen synthesis methods adopt the mixing of o-aminophenol and acetic anhydride to generate products. However, most of the existing synthetic methods are complicated in process, and the final yield is not very high. Therefore, it is necessary to propose a new synthetic method, which is useful for further improving the quality and yield of the product and reducing the content of by-products. important economic significance. Contents of the invention [0003] The object of the present invention is to provide a kind of synthetic method of drug intermediate o-acetaminophen, comprising the steps of: [0004] (i) Mix 3mol o-aminophenol with 12-15L formic acid solution, control the sti...

Claims

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Application Information

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IPC IPC(8): C07C231/02C07C231/24C07C233/25
CPCC07C231/02C07C231/24C07C233/25
Inventor 彭响亮
Owner CHENGDU ZHONGHENG HUATIE TECH CO LTD
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