| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optically active carboxylic acid which is useful as a medicine and so on at a low reaction temperature in a short reaction time by forming an salt with an optically active amine to dominantly crystallize a salt of one optical isomer with isomerizing an optically active isomer of a specific carboxylic acid in the presence of a specific base, followed by treating with an acid. SOLUTION: This optically active carboxylic acid is obtained by dominantly crystallizing a salt of one optical isomer by forming an salt with an optically active amine (preferably an α-arylethylamine) which is shown preferably by the formula [R1 and R2 are mutually different (substituted) aryl or the like] and has an asymmetric carbon atom bound to one hydrogen atom at α-position (preferably flurbiprofen and so on) in the presence of a base preferably 1,8- diazabicyclo-[5,4,0]-undec-7-ene and so on} which is stronger than the optically active amine, followed by treating the obtained crystallized salt with an acid. |
