Syntheses of Methyl Dihydroxybenzoates by the Reactions of Methyl Salicylate with Organic Peroxides

Abstract

The hydroxylation of methyl salicylate with organic peroxides was investigated. Isobutyl methyl ketone peroxide and acidic solids such as activated clay and diboron trioxide were found to be suitable as the peroxide and the catalyst for this reaction. The main products under theses conditions were methyl 2, 3- and 2, 5-dihydroxybenzoates, in the 2, 3- to 2, 5- product ratio of 0.6∼0.8. In contrast to isobutyl methyl ketone peroxide which gave the methyl dihydroxybenzoates in 65∼69% yield based km the peroxide, hydrogen peroxide (8.0%), t-butyl hydroperoxide (1.4%), and performic acid (12.8%) formed in situ, behaved poorer as an oxidant.