PURPOSE: To obtain the titled compound useful as an anti-inflammatory drug or analgesic while suppressing variability of resolution efficiency, by subjecting a 2-(6-methoxy-2-naphthyl)propionic acid lower alkyl ester to optical resolution in the presence of a base by preferential crystallization.
CONSTITUTION: A racemic modification of 2-(6-methoxy-2-naphthyl)propionic acid lower alkyl ester or a mixture wherein one of optical active substance exists in a larger amount than the other is dissolved in a solvent such as methanol, etc. in the presence of a base such as an alkali metal, diazabicycloundecene, etc. Then, one of the optical active substances is inoculated into the solution, and optical resolution is carried out by preferential crystallization. In the operation, it is required to keep the total of the molar fraction of 2-(6-methoxy-2- naphthyl)propionic acid and its salt ≤7%, preferably ≤5%.
ARAI KAZUTAKA
TAKAKUWA YASUO
