GB754872A - Improvements in or relating to the preparation of a mixture of cymene isomers rich in m- and p-cymene - Google Patents

Abstract

A mixture of cymene isomers rich in m- and p-cymene is obtained by contacting toluene with propylene in an amount up to a 0.6 molecular quantity based on the toluene at a temperature of 80-150 DEG C. in the presence of 0.1 to 2 mol. per cent of aluminium chloride until a mixture of m- and p-cymenes containing less than 5 per cent o-cymene is produced, and separating the mixture from the catalyst. The time for the alkylation step is about 1 hour at 100 DEG C. The m- and p-cymenes may be subjected to oxidation as described in Specifications 610,293, 626,095, 630,286 and 681,990, with molecular oxidation under conditions favourable to hydroperoxide formation until 35 per cent of hydroperoxide is produced. These may be converted to cresols by contacting them with an acid acting catalyst such as sulphuric acid, acid clays and Friedel-Craft catalysts in aqueous or non-aqueous homogeneous or heterogeneous systems at a temperature of 0-150 DEG C. until the hydroperoxides are completely destroyed.