Catalytic Synthesis of Butyl Isovalerate by Brønsted Acidic Ionic Liquid under Microwave Irradiation

Abstract

Butyl isovalerate was synthesized from isovaleric acid and butanol with ionic liquid as catalysts under microwave irradiation. The systematic study was investigated including of the effects of molar ratio of acid to alcohol, microwave power, amount of catalyst, microwave time and microwave temperature on the process. The optimum operation conditions were as follows: n(butanol):n(isovaleric acid) = 1.6:1, microwave power 500 W, amount of catalyst of 6 wt % to isovaleric acid, microwave time of 0.5 h and microwave temperature of 110 ºC. The yield of butyl isovalerate could reach 92.1 % under the optimal operation conditions mentioned above. The excellent durability and recycle ability of ionic liquids were also addressed even after five times reused.