4-羟基-5,6,8-三甲氧基喹啉-2-羧酸乙酯(1)是合成白内障治疗药吡诺克辛(pirenoxine,cataline,白内停)的中间体。文献[1～3]以2,4,5-三甲氧基苯胺(2)为原料与丁酮二酸二乙酯(3)加成脱水,再脱醇环合而制得。其收率为30%[1]、42%[2]或57%[3](以2计)。本文以此合成路线合成1,改进后 Ethyl 4-hydroxy-5,6,8-trimethoxyquinoline-2-carboxylate (1) is an intermediate for the synthesis of pirenoxine (cataline). Literature [1 ~ 3] to 2,4,5 - trimethoxy aniline (2) as raw materials and butylene ketal diethyl ester (3) dehydration, and dealcoholation obtained. The yield is 30% [1], 42% [2] or 57% [3] (calculated as 2). This synthesis of synthetic route 1, improved