PREPARATION OF PHENOL DERIVATIVE

PURPOSE:To obtain the titled compound useful as an intermediate for a pressure- sensitive or heat-sensitive dyestuff in high yield, by hydrolyzing an O,N-diacyl- 3-halogeno-4-aminophenol with an alkali in an aqueous medium. CONSTITUTION:A compound shown by the formula I (R is lower alkyl; X is halogen) is treated with an alkali (e.g., sodium hydroxide) in an aqueous medium (e.g., water) to give the desired phenol derivative shown by the formula II. An amount of the alkali used in the reaction is >=1 equivalent, preferably 1- 5 equivalent based on the raw material compound, and the reaction is carried out at 0-100 deg.C, preferably at 20-80 deg.C. Only the acyloxy group of the compound shown by the formula I is selectively hydrolyzed by the hydrolysis under the condition, to give the phenol derivative shown by the formula II. The compound shown by the formula I is obtained by diazotizing p-aminophenol, reacting it with chlorine or bromine.