Triphenylphosphine Catalysed Facile Multicomponent Synthesis of 2-Amino-3-Cyano-6-Methyl-4-Aryl-4H-Pyrans

Triphenyl phosphine (PPh3), an efficient and reusable catalyst, catalysed the synthesis of 2-amino-3-cyano-6-methyl-4-aryl-4H-pyran-5-ethylcarboxylate derivatives by one-pot condensation of aromatic aldehydes, malononitrile and ethyl acetoacetate in EtOH-H2O (1:1) at reflux conditions. The results show that aromatic aldehydes containing electron-donating groups or electron-withdrawing groups could react smoothly to give the corresponding products in good to excellent yields. Given the increasing levels of interest in green chemistry, the recyclability and reusability of the catalyst have been evaluated. It was also found that triphenyl phosphine can be recycled at least four times without loss of activity. This method has the advantages of high yield, mild reaction conditions, environmentally benign methodology and short reaction time.