Process for the preparation of o-substituted benzal bromides and benzyl bromides

摘要

Benzal bromides and/or benzyl bromides which contain an electron-withdrawing substituent in the o-position are prepared by brominating toluene, which contains an electron-withdrawing substituent in the o-position using a positive N-bromo compound in a symmetrically halogenated alkane or alkene hydrocarbon and in the presence of a free-radical initiator at temperatures between 80 and 110 DEG C. The products are obtained in excellent yield and purity.