PREPARATION OF 4-BROMOMETHYL-5-METHYL-1,3-DIOXOL-2-ONE

摘要

PURPOSE:To improve the yield of the titled compound useful as an intermediate of pharmaceuticals in the bromination of 4,5-dimethyl-1,3-dioxol-2-one with molecular bromine under specific condition, by heat-treating the reaction mixture under specific condition after the completion of the reaction. CONSTITUTION:4,5-Dimethyl-1,3-dioxol-2-one of formulaIis brominated economically by reacting with economically available molecular bromine in an inert solvent at 10-90 deg.C, preferably 30-85 deg.C. The obtained reaction mixture is, if necessary after the removal of the inert slovent therefrom, heat-treated at 95- 160 deg.C, preferably at 100-150 deg.C for =1hr, preferably =1.5hr to convert a part of the dibrominated compound by-produced in the bromination reaction to the objective compound. The 4-bromomethyl-5-methyl-1,3-dioxol-2-one of formula II can be prepared in high yield by this process.