A process for preparation of 4-mercapto-1-naphthol compounds which comprises the steps of: (i) obtaining a 4-heterocyclylthio-1-naphthol compound by reacting a 1-naphthol compound with a heterocyclylsulfur chloride or by reacting a 4-iodo-1-naphthol compound with an alkali metal or ammonium salt of a mercaptoheterocyclic compound, (ii) hydrolyzing the resulting 4-heterocyclylthio-1-naphthol compound in the presence of a base to form a reaction product, and (iii) acidifying said reaction product. The resulting compounds are useful as intermediates in the synthesis of bleach accelerator releasing couplers for use in silver halide color photographic materials.