Synthesis method of high-purity lornoxicam

Abstract

The invention belongs to the technical field of medicine synthesis, and particularly relates to a synthesis method of high-purity lornoxicam. The method comprises the following steps: by taking 6-chloro-4-hydroxy-2-methyl-2-H-thieno [2, 3-e]-1, 2-thiazine carboxylic acid methyl ester-1, 1-dioxide and 2-aminopyridine as raw materials and xylene as a solvent, carrying out distillation reaction, condensing mixed gas obtained by the distillation reaction to obtain condensate, adsorbing methanol in the condensate by adopting a solid acid catalyst, and recycling the adsorbed condensate. According to the invention, the methanol generated by the reaction is distilled out so as to promote the reaction to proceed forwards, and then the methanol is absorbed under the catalysis of H2SO4 / MxOy superacid solid acid, so that the xylene returned to the reaction system does not contain methanol, and the coking of the reaction is reduced so as to improve the product quality and yield; and the purity of the prepared lornoxicam is high and can reach 99.9% or above, the solvent amount is reduced, and the method is suitable for industrial production.

Description

technical field [0001] The invention belongs to the technical field of medicine synthesis, and in particular relates to a synthesis method of high-purity lornoxicam. Background technique [0002] Lornoxicam, an anti-inflammatory analgesic, was developed by Nycomed, a Norwegian company, and was included in the analgesic ladder program formulated by the World Health Organization. Lornoxicam can be taken orally or injected, and is mainly used for the treatment of mild to moderate pain caused by rheumatoid arthritis, rheumatoid arthritis or routine surgery, low back pain, etc. [0003] The synthetic method of lornoxicam is numerous at present, mainly contains following two routes: [0004] Route 1: In 1997, Norwegian Nycomed Company used 2,5-dichlorothiophene as the starting material to synthesize lornoxicam through 7 steps of reaction: [0005] [0006] This synthetic route has many steps, the total yield is relatively low and the pollution is serious. Reagents such as n-b...

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Problems solved by technology

Therefore, the residue of methanol will increase the reaction by-products, resulting in severe coking, resulting in a decrease in yield and affecting product quality

[0011] "Ion Exchange and Adsorption", 1992, 8 (1), 44-47, mentioned that HNA resin is used to adsorb methanol, but HNA resin cannot completely absorb methanol in the xylene system, and a small amount of methanol will return to the reaction system, resulting in a reaction When coking occurs, the product purity is still not high

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