Abstract
An efficient route for the synthesis of 2-amino-4H-pyrans and pyran annulated heterocyclic moieties has been reported via one-pot tandem Knoevenagel–cyclocondensation of aldehydes, malononitrile, and carbocyclic/heterocyclic 1,3-diones in the presence of stabilized nickel nanoparticles in ethylene glycol at room temperature. A wide range of aromatic aldehydes undergo the condensation readily to afford the pharmacologically important compounds in excellent yields. Bis-pyranization has been observed in the reactions of terephthaldehyde.
Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.
GRAPHICAL ABSTRACT
ACKNOWLEDGMENT
K.V. is thankful to the Council of Scientific and Industrial Research, New Delhi, India, for the award of junior and senior research fellowships.