Selective ortho-alkylation of phenol cpds. - using catalyst based on chromium and tin oxide cpds. with low temp. activity and long life

摘要

Selective ortho-alkylation of a phenolic cpd. (I) having an H atom in the ortho-position(s) by catalytic vapour phase reaction with a (satd. 1-4C) alcohol (II) is carried out in the presence of a mixed oxide catalyst (III) contg. Cr and Sn as active substances. 2,4-Dimethylphenol is useful as a starting material for the prodn. of polyphenylene oxide. The process is highly selective and gives a high degree of conversion of (I). The catalyst has satisfactory activity at low temp. and a long useful lifetime.