Synthesis of novel spiro[indoline-3,7′-pyrrolo[1,2-c]imidazole]-6′-carbonitrile derivatives in water using a regioselective sequential three component reaction

A novel and straightforward method for the synthesis of pharmacologically promising spiro[indoline-3,7'-pyrrolo[1,2-c]imidazole]-6'-carbonitrile derivatives has been developed by a sequential three component one-pot reaction of isatin, malononitrile and hydantoin or thiohydantoin derivatives catalyzed by Et3N in water, an environmentally friendly reaction medium. This method provides clean and efficient access of privileged spirooxindole derivatives tethered with pyrrolizidine moiety from the readily available starting materials.