Study On Synthesis Of 4-Bromo-a,a-dimthylbenzenacetic Acid

In this paper, 4-bromo-α,α－dimthylbenzenacetic acid was prepared starting from 4-bromophenylacetonitrile by the methods of methylation and then hydrolyzation. In the first step, 4-bromo-α,α－dimthylbenzeneacetonitrile was successfully synthesized from 4-bromophenylacetonitrile by the methylation in accordance with the principle of phase transfer catalysis, in which catalyst was methyltrioctyl ammonium. At the same time, the effects of some factors, such as the amount of sodium hydroxide, methyltrioctyl ammonium chloride, water, and their feed ratio used in the methylating process, on the yield of 4-bromo-α,α－dimthylbenzeneacetonitrile were discussed, and the better methylating conditions were determined. It was shown that both the yield and purity of 4-bromo-α,α－dimthylbenzeneacetonitrile are higher than those reported in the literature by the other method.In the step of hydrolyzation, we studied systematically the factors affecting the reaction time and yield of hydrolyzation, such as the amount of potassium hydroxide, ethanol, water and their feed ratio. The better process conditions were obtained, and the yield was close to those reported in the literature. The present study provided a new method of synthesizing the title compound, and it had importance in the industrial production of 4-bromo-α,α－dimthylbenzeneacetic acid.