New method for the preparation of benzoic acid derivatives.

SE provides a process industrially advantageous for producing a benzoic acid derivative of the formula (V), which has a good activity retinoid with high safety, the process comprises the steps of CARRY OUT A REACTION "Friedel-Crafts" BETWEEN ACETANILURO WHICH IS easy to find and work and, 2,5-dimethyl ENDO AZIL EXCHANGE BETWEEN THE rEACTION PRODUCT AND ESTER CHLORIDE monomethyl terephthalic acid, hydrolyzing the reaction product, and recrystallizing the hydrolyzate from methanol /WATER. VARIOUS STEPS REACTION take place in a single vessel. CRYSTALS compound obtained are suitable for pharmaceutical preparation BECAUSE OF CONTAINING AN AMOUNT REDUCED RESIDUAL SOLVENT recrystallization AND UNIFORMS particle sizes.