Process for the o-substitution of phenols

In a process for the production of o-substituted phenols by catalytically reacting phenols having at least one free o-position with alcohols or ethers in the presence of a catalyst containing iron oxide at an elevated temperature in the gaseous phase, the improvement which comprises reacting a compound selected from the group consisting of phenol, mono-alkyl phenol, and di-alkyl phenol with methanol or dimethyl ether in a molar ratio of 1:0.1-10 at a temperature of between 270.degree. C.-390.degree. C. for 0.05 to 10 seconds in the gaseous phase in the presence of a four component catalyst consisting essentially of (a) iron oxide, (b) vanadium oxide, (c) at least one oxide of a metal of the group consisting of boron, aluminum, titanium, zirconium, silicon, germanium, tin and lead, and (d) at least one oxide of a metal of the group consisting of an alkali metal, an alkaline-earth metal, lanthanum and manganese when component (c) is an oxide of silicon or when component (c) is an oxide other than silicon, component (d) is at least one oxide of a metal of the group consisting of calcium, strontium, barium, an alkali metal and lanthanum.