Novel and highly efficient synthesis of 3-(alkyl/benzylthio)-9b-hydroxy-1H-imidazo[5,1-a]isoindole-1,5(9bH)-dione derivatives

Abstract The oxidation of 3a,8a-dihydroxy-2-(alkyl/benzylthio)indeno[1,2- d ]imidazol-8(3 H )-ones to give the corresponding 3-(alkyl/benzylthio)-9b-hydroxy-1 H -imidazo[5,1- a ]isoindole-1,5(9b H )-dione derivatives in good to excellent yields at room temperature using two oxidants, periodic acid in aqueous ethanol and lead(IV) acetate in acetic acid, has been reported.