| 摘要 |
PURPOSE:To obtain an optically active uricotelic agent containing a furobenzisoxazole derivative which is the S(-)-isomer as an active ingredient. CONSTITUTION:This uricotelic agent contains S(-)-5-chloro-7,8-dihydro-3-pheny1 furo[2,3-g]-1,2-benzisoxazole-7-carboxylic acid expressed by formula I as an active ingredient. The compound expressed by formula I is obtained by dissolving a racemic modification expressed by formula II in an organic solvent, separating one optical isomer that is the R(+)-isomer with a basic optical resolving agent comprising preferably (-)-cinchonidine, then recovering a carboxylic acid substance from the mother liquor, adding a basic optical resolving agent preferably comprising (+)-phenylethylamine, etc., to the recovered carboxylic acid substance, depositing a crystal, repeating the recrystallization, purifying the resultant crystal, subsequently acidifying the crystal, removing bases and further repeating the recrystallization. |
