PURPOSE: To provide an efficient method for production of a phenol having a substituent group according to a reaction exhibiting a high raw material conversion in a shorter time in comparison with the conventional method.
CONSTITUTION: In production of a phenol containing a substituent group through a formic acid ester from a corresponding benzaldehyde containing a substituent group, synthesis of the formic acid ester from the corresponding benzaldehyde containing a substituent group is carried out by conducting oxidation in the presence of a peracid without using water and hydrolysis of the resultant formic acid ester is conducted in the presence of a base or water without isolation of the formic acid ester. Excessive oxidizing agents are thermally decomposed and converted into a carboxylic acid without removal by reduction and the resultant product is purified according to crystallization or distillation.