process for the preparation of m - and m - fenossibenzil fenossi - benzal halides useful as intermediates for the production of pesticides

摘要

Reaction of 3-phenoxytoluene with bromine at elevated temperature yields 3-phenoxybenzyl bromide, 3-phenoxybenzal bromide, or a mixture thereof. In contrast to teachings of the prior art, phosphorus halide catalysis or u.v. activation is not required to achieve a desirable amount of side-chain bromination with a minimum of nuclear halogenation. For example, it was observed that at 265+/-5 DEG C., good yields of the desired benzyl and benzal bromide were obtained, but no nuclear halogenated by-product was detected by gas chromatography.