2-异丙基戊酸的合成

Synthesis of 2-Isopropyl Pentanoic Acid

为提高常用抗癫痫药丙戊酸钠的质量,合成了它的有关物质2-异丙基戊酸(1)。用氰乙酸甲酯(2)和溴丙烷在甲醇钠的甲醇溶液进行烷基化反应得到2-氰基戊酸甲酯(3)。3和2-碘丙烷在甲醇钠的甲醇溶液中反应得到2-氰基-2-异丙基戊酸甲酯(5)。5经硫酸水解、脱羧,再经氢氧化钠水解和硫酸酸化得到1,总收率约4%,纯度98%。

To improve the quality of sodium valproate,a commonly used anti-epileptic drug,its related substance 2-isopropyl pentanoic acid(1)was synthesized.The compound methyl 2-cyano-valerate(3)was obtained by the reaction of methyl cyanoacetate(2)and bromopropane in methanol solution of sodium methoxide.And then,3 was reacted with 2-iodopropane in methanol solution of sodium methoxide to synthesize methyl 2-cyano-2-isopropyl valenate(5).Followed by hydrolysis and decarboxylation,hydrolysis with sodium hydroxide and acidification with sulfuric acid,the title compound 1 was obtained with a total yield of 4%and the purity of 98%.