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Pharmaceutical intermediate 2,5-dichlorobenzoic acid synthesis method

A technology for the synthesis of dichlorobenzoic acid and its synthesis method is applied in the field of synthesis of pharmaceutical intermediate 2,5-dichlorobenzoic acid, which can solve the problems of low final yield and complicated process, shorten the reaction time and reduce intermediate link, the effect of improving the reaction yield

Inactive Publication Date: 2018-07-03
CHENGDU DONG DIAN AI ER TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] 2,5-dichlorobenzoic acid is mainly used as pesticide, pharmaceutical intermediate and organic synthesis intermediate, and is used to synthesize herbicides Tou Kewei and Dizao Ping. However, most of the existing synthetic methods use p-dichlorobenzene and Phosgene reacts to obtain 2,5-dichlorobenzoyl chloride, which is obtained through hydrolysis, and the process is more complicated, 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 product quality. Quality and yield, reducing by-product content is of great economic significance

Method used

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  • Pharmaceutical intermediate 2,5-dichlorobenzoic acid synthesis method

Examples

Experimental program
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Effect test

example 1

[0010] Add 2mol of 2,5-dichloro-6-aminobenzoic acid and 3mol mass fraction of 70% diisobutyl adipate solution in the reaction vessel, raise the solution temperature to 70°C, control the stirring speed to 130rpm, divide Add 3 mol of cobalt naphthenate 3 times, the interval between each time is 30min, continue the reaction for 90min, add 1200ml of potassium chloride solution with a mass fraction of 15%, the solution is layered, reduce the solution temperature to 10°C, and add a mass fraction of 20 % oxalic acid solution to adjust pH to 4, mass fraction is 10% potassium sulfate solution washing, mass fraction is 80% methyl tert-butyl ether solution washing, mass fraction is 90% 2-methyltetrahydrofuran solution washing, 15kPa Distilled under reduced pressure, collected fractions at 110°C, and dehydrated with anhydrous sodium sulfate dehydrating agent to obtain 351.44 g of finished product 2,5-dichlorobenzoic acid with a yield of 92%.

example 2

[0012] Add 2mol of 2,5-dichloro-6-aminobenzoic acid and 4mol mass fraction of 73% diisobutyl adipate solution in the reaction vessel, raise the solution temperature to 75°C, control the stirring speed to 140rpm, divide Add 3.5mol of cobalt naphthenate 4 times, each interval is 35min, continue to react for 110min, add 1200ml of potassium chloride solution with a mass fraction of 18%, the solution is layered, reduce the solution temperature to 12°C, add a mass fraction of 22% oxalic acid solution to adjust pH to 4.5, mass fraction is 14% potassium sulfate solution washing, mass fraction is 80% methyl tert-butyl ether solution washing, mass fraction is 93% 2-methyltetrahydrofuran solution washing, Distilled under reduced pressure at 18kPa, collected fractions at 115°C, and dehydrated with a dehydrating agent to obtain 359.08g of finished product 2,5-dichlorobenzoic acid with a yield of 94%.

example 3

[0014] Add 2mol of 2,5-dichloro-6-aminobenzoic acid and 5mol mass fraction of 76% diisobutyl adipate solution in the reaction vessel, raise the solution temperature to 78°C, control the stirring speed to 160rpm, divide Add 4 mol of cobalt naphthenate 5 times, the interval between each time is 40min, continue the reaction for 120min, add 1200ml of potassium chloride solution with a mass fraction of 22%, the solution is layered, reduce the temperature of the solution to 15°C, and add a mass fraction of 25% % oxalic acid solution to adjust pH to 5, mass fraction is 18% potassium sulfate solution washing, mass fraction is 85% methyl tert-butyl ether solution washing, mass fraction is 96% 2-methyltetrahydrofuran solution washing, 20kPa minus Pressure distillation, collecting fractions at 120°C, and dehydrating with a dehydrating agent, yielded 370.54 g of finished product 2,5-dichlorobenzoic acid with a yield of 97%.

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Abstract

The invention relates to a pharmaceutical intermediate 2,5-dichlorobenzoic acid synthesis method, which mainly comprises: adding 2 mol 2,5-dichloro-6-aminobenzoic acid and 3-5 mol diisobutyl adipate solution to a reaction container, increasing the solution temperature to 70-78 DEG C, controlling the stirring speed at 130-160 rpm, adding 3-4 mol cobalt naphthenate in 3-5 times every 30-40 min, continuously carrying out the reaction for 90-120 min, adding 1200 ml of a potassium chloride solution, layering the solution, reducing the solution temperature to 10-15 DEG C, adding an oxalic acid solution, adjusting the pH value to 4-5, washing with a potassium sulfate solution, washing with a methyl tert-butyl ether solution, washing with a 2-methyl tetrahydrofuran solution, carrying out pressurereducing distillation, collecting the distillate at a temperature of 110-120 DEG C, and dehydrating with a dehydrating agent to obtain the finished product 2,5-dichlorobenzoic acid.

Description

technical field [0001] The invention relates to a method for synthesizing a pharmaceutical intermediate 2,5-dichlorobenzoic acid. Background technique [0002] 2,5-dichlorobenzoic acid is mainly used as pesticide, pharmaceutical intermediate and organic synthesis intermediate, and is used to synthesize herbicides Tou Kewei and Dizao Ping. However, most of the existing synthetic methods use p-dichlorobenzene and Phosgene reacts to obtain 2,5-dichlorobenzoyl chloride, which is obtained through hydrolysis, and the process is more complicated, 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 product quality. Quality and yield, reducing by-product content has 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 2,5-dichlorobenzoic acid, comprising the steps: [0004] (i) Ad...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C51/16C07C63/70
CPCC07C51/16C07C63/70
Inventor 严义达
Owner CHENGDU DONG DIAN AI ER TECH
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