PROCESS FOR PRODUCING CATECHOL DERIVATIVES

摘要

An improved process for producing catechol derivatives (1) useful as intermediates for compounds useful as drugs or agricultural chemicals, which comprises the reaction steps shown above. In said process (I), R represents alkyl, cycloalkyl, aralkyl, alkoxy, halogeno, allyl or aryl, and R<1> represents a hydroxy-protecting group. The process is characterized in that formylation as the first step is conducted in the presence of a tin catalyst in two stages, first at 60 to 85 DEG C to a conversion of 30 to 80 % and then at 95 to 105 DEG C to completion, to thereby obtain a salicylaldehyde (3) in a high yield with a high selectivity. The objective catechol derivatives (1) having a high purity are hence obtained in a high yield.