Synthesis of Antipsychotic Drug Risperidone
Guan Yihe, Yu Xiaohong, Wang Xijuan (Zhejiang Jianfeng Haizhou pharmatical Co. Ltd, Taizhou, Zhejiang 317016)
A process for risperidone synthesis was designed and validated. 6-Fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride was synthesized from 4-piperidinecarboxlic acid through acetylation, chlorination, Fiedel crafts reaction, hydrolysis, oximation and cyclization. 3-(2-Chloroethyl)-6,7,8,9-tetrahydro-2-methyl- 4H-pyrido[1,2-α]pyrimidin-4-one was synthesized from 2-aminopyridine in 2 steps of condensation and hydrogenation reduction. Risperidoneis obtained from the two compounds through condensation, in the total yield of 12%. 1,2-Dichloroethane is used as a solvent for the separation with palladium on carbon as the best catalyst, the best dosage is 5% by mass. The process conditions are mild and raw materials are easily available, which is suitable for industrialization production.