Facile one pot microwave assisted solvent-free synthesis of novel spiro-fused pyran derivatives via the three-component condensation of ninhydrin with malononitrile and active methylene compounds

Three-component condensation of ninhydrin, malononitrile, and some nucleophilic reagents in the presence of piperidine under microwave irradiation without solvent afforded the corresponding spiro-fused pyran derivatives. The structures of the products were proved by elemental analyses, IR, H-1 NMR and MS spectroscopy.