| abstract |
(57) Abstract: The present invention relates to a benzoic acid derivative having retinoid activity and represented by the following general formula: Is intended to provide an industrially advantageous synthesis method which can be obtained easily, with good yield, and safely. According to the present invention, acetoanilide, which is easily available and easily handled, is subjected to a Friedel-Crafts reaction with 2,5-dimethyl-2,5-dichlorohexane as a starting material, and the obtained compound is terephthalic acid. Benzoic acid derivative represented by the following general formula, characterized in that several different operations of acyl exchange with monomethyl chloride, followed by hydrolysis and recrystallization from methanol-water are carried out in a one-vessel reaction. Are provided. The novel crystalline form obtained by the present synthesis method is suitable for formulation because it has little residual recrystallization solvent and uniform particle size. |