Method for producing diarylmethane or its derivatives

Abstract

A method to produce diarylmethane or its derivatives by condensation reaction can be carried out without difficulty and without the deterioration of catalyst, and the intended product can be produced inexpensively by recovering and recycling used alcohol. In the method, dimethoxymethane and an aromatic compound are reacted at a temperature of 80 to 400° C. with an acid catalyst. Further, the method comprises the steps of (1) reacting alcohol with formaldehyde using an acid catalyst to obtain acetal; (2) reacting the acetal and an aromatic compound using an acid catalyst to obtain a reaction mixture containing diarylmethane or its derivatives and alcohol; (3) separating and recovering diarylmethane or its derivatives and alcohol from the reaction mixture, and (4) recycling at least a portion of the recovered alcohol to the step (1).

Dependencies are inferred from the claim text.