Preparation method of praziquantel

The invention relates to the technical field of medical intermediates, and provides a praziquantel preparation method which comprises the following steps: S1, adding isoquinoline, cyanide, tetrabutylammonium bromide and dichloroethane into a reactor, and dropwise adding benzoyl chloride for reaction to obtain a first-step product; s2, performing catalytic hydrogenation on the first-step product to obtain a second-step product; and S3, adding ethyl acetate into the second-step product, stirring and dissolving, adding sodium bicarbonate, dropwise adding chloroacetyl chloride, stirring and reacting to obtain a praziquantel crude product, and recrystallizing to obtain praziquantel. Through the technical scheme, the problems of long reaction process, high energy consumption and low yield in the prior art are solved. 本发明涉及医药中间体技术领域，提出了一种吡喹酮的制备方法，包括以下步骤：S1、将异喹啉、氰化物、四丁基溴化铵和二氯乙烷加入反应器中，滴加苯甲酰氯反应得到第一步产物；S2、第一步产物催化加氢得到第二步产物；S3、第二步产物加入乙酸乙酯搅拌溶解后加入碳酸氢钠，然后滴加氯乙酰氯，搅拌反应后得到吡喹酮粗品，经重结晶得到吡喹酮。通过上述技术方案，解决了现有技术中的反应流程长、能耗高、收率低的问题。