Sodium Bismuthate: An Efficient Catalyst for the One-pot Synthesis of Biologically Active Spiro[4H-pyran] Derivativesunder Solvent-free Conditions

Abstract

An efficient sodium bismuthate (NaBiO3) synthesis of biologically active spiro[4H-pyran]<br />derivatives has been accomplished via one-pot three-condensation of isatin/acenaphthequinone, malononitrile and different reagents including 1,3-dicrbonyl compounds, α-naphthol and 4-hydroxycumarin under solvent-free conditions. The notable advantages of the present procedure are: eco-friendly, environmentally benign nature,low-cost and non-toxic catalyst, simplicity of operation with no necessity of chromatographic<br />purification steps, short reaction times, good to high yields and solvent-free conditions. <br /><br />