| 摘要 |
PROBLEM TO BE SOLVED: To obtain a racemic carboxylic acid useful as an intermediate raw material for medicines and agrochemicals in high yield by reducing the amount of a base used and racemizing an optically active carboxylic acid under mild conditions. SOLUTION: The racemizing reaction of an optically active carboxylic acid represented by the formula (R<1> and R<2> are each hydroxyl, a 1-10C alkyl, a 6-10C aryl, a 7-11C aralkyl or a 5-6C cycloalkyl; X is H or an alkali metal) or an alkali metallic salt thereof is carried out in the coexistence of a base (e.g. potassium hydroxide) and dimethyl sulfoxide at 60-130 deg.C for 0.1-40hr. The base is used in an amount of 1.01-10 equiv. based on the optically active carboxylic acid and 0.01-9 equiv. based on the alkali metallic salt of the optically active carboxylic acid. The dimethyl sulfoxide is used in an amount of 0.1-10 times based on the optically active carboxylic acid (alkali metallic salt). An organic solvent (e.g. cyclohexane) and water may coexist in racemization. |
