Process for the hydroxylation of phenols and phenol ethers in the nucleus

In a catalytic process for the hydroxylation of the nucleus of a phenol or phenol ether wherein a phenol or phenol ether is contacted with hydrogen peroxide at a temperature of 20.degree.-150.degree. C and at a pressure of 0.1 to 500 Torr employing 3 to 20 moles of said phenol or phenol ether per mole of hydrogen peroxide and the resulting hydroxylated phenol or phenol ether is recovered, the improvement which comprises employing a substantially anhydrous hydrogen peroxide obtained by distilling off said hydrogen peroxide together with the phenol or phenol ether to be hydroxylated from a nonaqueous solution whose solvent boils at a temperature higher than said phenol or phenol ether to be hydroxylated and affecting the hydroxylation in the presence of a strong acid either before or after condensing the vapor mixture which forms during the said distillation.