3-正丙基-5-羧基-1-甲基吡唑的合成研究

Synthesis of 1-Methyl-3-n-propylpyrazole-5-carboxylic Acid

以 2 -戊酮和草酸二乙酯为起始原料 ,经 Claisen缩合、环化、甲基化和皂化等反应制得目标化合物 3-正丙基 - 5 -羧基 - 1 -甲基吡唑 3。文献报道的合成方法为四步法 ,在此基础上加以改进 ,形成了两种新的合成路线 ,即三步法和两步法 ,其收率均高于四步法 ,高出 2 7.0 %

Methyl 3 n propylpyrazole 5 carboxylic acid 3 was prepared from 2 pentanone and diethyloxalate as starting materials. The synthetic route reported in literature consists of four steps, i.e. Claisen condensation, cyclization, methylation and hydrolysis. Two new routes with two steps and three steps are interduced. The yields of the three step and two step methods are 27.0% more than that of the four step method.