Selective ortho methylation of phenols - by catalytic reaction with methanol

摘要

Selective methylation in the o-posn of phenols of formula (I): (where R1, R2, R3 and R4 (same or different)=H or satd 1-6C aliphatic hydrocarbon gps is carried out by reacting (I) with MeOH in the vapour phase at elevated temps using a 3-component CeO2-MgO-GeO2 catalyst or a 4-component CeO2-MgO-GeO2-SnO2 catalyst. Pref. reaction is at 300-500 degrees C using a solid or fluidised bed catalyst with a 1:1-15 mol ratio I:MeOH. Process is esp. useful for making o-phenol from m-cresol.