Preparation method of diclofenac

Abstract

The invention belongs to the technical field of chemical drug synthesis, and particularly relates to a preparation method of diclofenac. The preparation method comprises the following steps: (1) adding 2-chlorophenylacetic acid or 2-chlorophenylacetate and a polar aprotic solvent into a reaction bottle, performing dissolution under stirring, adding 2,6-dichloroaniline, an alkali, a catalyst and areaction accelerator, performing heating under stirring to 120-160 DEG C, and performing heat preservation for a reaction for 2-24 h, wherein the catalyst is nano copper oxide or nano cuprous iodide;and (2) cooling the reaction mixture obtained in the step (1) to 70-90 DEG C, performing filtration, performing reduced-pressure distillation on the filtrate to obtain a crude product, performing purification on the crude product, and performing drying to obtain the diclofenac. According to the method provided by the invention, the catalyst has high catalytic efficiency and a small usage amount, areaction solvent is easy to recover, the production costs are low, the prepared product has a high yield, high purity and high quality, and the industrial production application is easy to realize.

Description

technical field [0001] The invention belongs to the technical field of chemical drug synthesis, and in particular relates to a preparation method of diclofenac. Background technique [0002] Diclofenac is the free acid of diclofenac. Diclofenac sodium (diclofenac sodium) is the third generation of non-steroidal powerful anti-inflammatory analgesics. It was listed in my country in the mid-1980s and is clinically used for various types of rheumatoid arthritis, lupus erythematosus, neuritis, cancer, and postoperative diseases. Pain and fever caused by various reasons. Compared with other anti-inflammatory analgesics, its curative effect is stronger, 2-2.5 times stronger than indomethacin, 20-50 times stronger than aspirin; oral absorption is rapid, and the peak blood concentration can be reached in 2 hours; excretion is fast, long-term use without accumulation Function; this product occupies a leading position in antirheumatic drugs. [0003] There are many reports about the ...

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Problems solved by technology

[0003] There are many reports about the synthetic method of diclofenac, wherein the most concise synthetic method is to use 2-chlorophenylacetic acid or 2-chlorophenylacetic acid salt as starting material, and one-step preparation of diclofenac through Ullamann reaction, the route of this synthetic method is the shortest, easy to operate Simple, has good industrialization value; But the ubiquitous problem of this synthetic method at present is: the reaction yield is low, and the highest yield of diclofenac is only 42.9% (yield recorded in existing documents), and catalyst (copper or copper Salt) is used in a large amount, and there are many industrial wastes, which cause great environmental pollution

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