Preparation method of avalatropag maleate intermediate

The invention relates to a preparation method of an atavtrombopag maleate intermediate, which comprises the following steps: dropwise adding phosphorus oxychloride into an intermediate 2, 5, 6-dichloronicotinic acid and pyridine in an organic solvent at-10-20 DEG C for reaction to obtain an intermediate 3; the intermediate 2 is 4-(4-chlorothiophene-2-yl)-5-(4-cyclohexyl piperazine-1-yl)-1, 3-thiazole-2-amine, and the intermediate 3 is 5, 6-dichloro-N-[4-(4-chlorothiophene-2-yl)-5 (4-cyclohexyl piperazine-1-yl)-1, 3-thiazole-2-yl] pyridine-3-formamide. The method is low in pollution, and the prepared intermediate 3 is high in yield and good in quality. 本发明涉及一种马来酸阿伐曲泊帕中间体的制备方法，将中间体2、5,6-二氯烟酸和吡啶在有机溶剂中，于-10℃～20℃，滴加三氯氧磷反应得到中间体3；所述中间体2为4-(4-氯噻吩-2-基)-5-(4-环己基哌嗪-1-基)-1,3-噻唑-2-胺，所述中间体3为5,6-二氯-N-[4-(4-氯噻吩-2-基)-5(4-环己基哌嗪-1-基)-1,3-噻唑-2-基]吡啶-3-甲酰胺。本发明方法的污染小、制得中间体3的收率高且质量好。