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Mefenamic acid short-process synthesis preparation and refining method

A technology of mefenamic acid and purification method, which is applied in chemical instruments and methods, preparation of organic compounds, preparation of cyanide reactions, etc., can solve the problems of high production cost, low product productivity, complicated technological process, etc., and achieves improved product quality. Yield, reduced production cost, simple process steps

Inactive Publication Date: 2013-12-04
JIANGSU BEIHEDE CHEM
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] The traditional synthesis of mefenamic acid is prepared by condensation of sodium o-chlorobenzoate and 2,3-dimethylaniline in the aqueous phase. The process is complicated, the product productivity is low, and the production cost is high.

Method used

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Examples

Experimental program
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Embodiment 1

[0020] Embodiment 1, the synthetic preparation and refining method of mefenamic acid: (1) add 10kg N,N-dimethylformamide (DMF) in the condensation kettle, then drop into 4kg of o-chlorobenzoic acid and 2kg of salt of wormwood, Stir for 10±2 minutes; (2) Add 7kg of 2,3-dimethylaniline, stir evenly, and add 0.15kg of catalyst. Heat the temperature in the kettle to 120~128°C, react for 2 hours under constant stirring, add 3N hydrochloric acid solution dropwise into the kettle, and adjust the pH of the reaction solution to 4.3±0.2. Turn on the frozen brine to cool down, lower the internal temperature to 5±5°C, stir and crystallize for 30±2 minutes.

[0021] The crude product of mefenamic acid was obtained by filtration. (making the product is the sodium salt of mefenamic acid, so add hydrochloric acid to adjust the ph, and separate out the product (3). Add 10kg of N,N-dimethylformamide in the reaction vessel, then drop into 5kg of mefenamic acid crude product, Heat and stir to d...

Embodiment 2

[0022] Embodiment 2 is basically the same as Example 1, but wherein the molar ratio of each component is, o-chlorobenzoic acid: 2,3-dimethylaniline: sodium carbonate: DMF: catalyst=1: 1.5: 0.4: 4: 0.04 . The molar ratio of each component in step (3)-(6) is: crude mefenamic acid: medicinal charcoal: DMF=1:0.08:1.2.

Embodiment 3

[0023] Embodiment 3 is basically the same as Example 1, but wherein the molar ratio of each component is o-chlorobenzoic acid: 2,3-dimethylaniline: sodium carbonate: DMF: catalyst=1: 4: 1.2: 7: 0.18 . The molar ratio of each component in step (3)-(6) is: crude mefenamic acid: medicinal charcoal: DMF=1:0.25:3.5.

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Abstract

A mefenamic acid synthesis preparation and refining method comprises the following steps: 1, adding o-chlorobenzoic acid and acid-binding agent at appropriate ratio in DMF for stirring; 2, adding a certain amount of 2,3-dimethyl aniline, and performing condensation reaction with a catalyst of suitable ratio at a certain temperature to obtain a mefenamic acid crude product; 3-6, allowing the mefenamic acid crude product to be subjected to refining including bleaching and crystallization in an organic solvent to obtain the mefenamic acid finished product, wherein the acid-binding agent adopts o-chlorobenzoic acid and sodium carbonate, the molar ratio of the o-chlorobenzoic acid to 2,3-dimethyl aniline to sodium carbonate to DMF to catalyst is 1:(2-3):(0.5-1):(5-6):0.05:0.15, and the temperature is 120-130 DEG C. Compared with the traditional process, the method has the advantages of high target product productivity, simple process procedures, mild reaction conditions, simple purifying process, high product purity and suitability for industrialized production; and the primary solvent N-dimethyl formamide can be recycled, so that the production cost is further reduced.

Description

technical field [0001] The invention relates to a method for synthesizing and refining chemicals, in particular to a method for synthesizing, preparing and refining mefenamic acid. Background technique [0002] Mefenamic acid, also known as flutter, is a non-steroidal anti-inflammatory drug that can inhibit the synthesis of prostaglandins, inhibit proteolytic enzymes, stabilize the protein structure of cell membranes, and interfere with tissue metabolism. It is often used to relieve short-term moderate pain, such as muscle pain, headache, toothache, etc. This product is also the precursor of synthetic acridine antimalarials and anticancer drugs. [0003] The traditional synthesis of mefenamic acid is prepared by condensation of sodium o-chlorobenzoate and 2,3-dimethylaniline in the aqueous phase. The process is complicated, the product productivity is low, and the production cost is high. Contents of the invention [0004] The purpose of the present invention is to provid...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C229/58C07C227/08C07C227/42
Inventor 邵琦王诚鲁海华
Owner JIANGSU BEIHEDE CHEM
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