Eco-friendly process for the synthesis of spiro-4H-pyran derivatives using Al2O3 as an efficient catalyst

An efficient and readily aluminium oxide (Al2O3) for the synthesis spiro-4H-pyran derivatives has been accomplished via one-pot condensation of isatin, malononitrile and different reagents including 1, 3-dicrbonyl compounds, naphthol and 4-hydroxycumarin. The notable advantages of the present procedure are: operational simplicity, solvent-free conditions, environmentally benign nature, low-cost and non-toxic catalyst, short reaction times and good yields.

Keywords:

Aluminium oxide (Al2O3) , Spiro-4H-pyran derivatives , Operational simplicity , Environmentally benign nature conditions.