Preparation method of flavoxate hydrochloride coupled impurity

The invention provides a preparation method of a flavoxate hydrochloride coupled impurity. The preparation method comprises the following steps: with a compound 2 (R is methyl, ethyl or hydrogen atom) as an initial material, performing a coupling reaction on two molecules first and then constructing a benzene ring branch chain structure, or constructing a branch chain structure and then performing coupling. By obtaining the coupled impurity, the impurity spectrum of flavoxate hydrochloride is clearer, and an analytical method is more accurate by inspecting the degree of separation of impurities, so that the quality of flavoxate hydrochloride active ingredient is further improved, and the curative effect and the safety are guaranteed. 盐酸黄酮哌酯偶联杂质的制备方法本发明提供了种盐酸黄酮哌酯偶联杂质的制备方法，以化合物2（R为甲基、乙基或氢原子）为起始物料，可以先进行两分子的偶联反应，再构建苯环支链结构，也可以先进行支链结构的构建再偶联。通过该偶联杂质的获得，可以使盐酸黄酮哌酯的杂质谱更加明确，并通过考察杂质之间的分离度，使分析方法更加准确，从而进步提高盐酸黄酮哌酯原料药的质量，保障疗效与安全性。