Method for the optical resolution of racemic 6-(4-aminophenyl)-4,5dihydro-5-methyl-3(2H)-pyridazinone

摘要

The present invention relates to a method for the optical resolution of racemic 6-(4-aminophenyl)-4,5dihydro-5-methyl-3(2H)-pyridazinone to enantiomers, which method comprises the following steps: a) contacting the racemic mixture with D- or L-tartaric acid in ethyl acetate solvent, b) recovering the crystalline salt therefrom; and c) optionally basifying the salt to form the corresponding free base.