Synthesis of 2-amino-4H-pyran derivatives in aqueous media with nano-SnO2 as recyclable catalyst

A nano-SnO2 catalyzed environmentally benign strategy for the synthesis of 2-amino-4H-pyran derivatives via the multi-component reaction between aryl aldehydes, β-dicarbonyl compounds and malononitrile in aqueous media under reflux conditions in excellent yields is established. The structures of the synthesized compounds were confirmed using IR, 1H-NMR. The elemental analysis and morphology of the catalyst was characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). This one-pot three component protocol provides an efficient improved pathway for the synthesis of pyrans in the terms of short reaction times, simple working up procedure and recyclability of catalyst.