One-pot synthesis of highly substituted pyridines has been demonstrated via multicomponent reaction of aldehydes, malononitrile and thiophenol using Mg-Al hydrotalcite as a solid base and reusable catalyst. The catalytic activity is intimately connected to the basicity of the catalyst. The best activities were observed with the Mg/Al: 5 catalyst. The catalyst could be reused for further run without a significant loss in activity. The protocol was also applicable for various aromatic aldehydes which affords desired product in good to excellent yield.

An efficient and simple synthesis of some 2-amino-3-cyano-4H-pyran derivatives was developed by the one-pot and three-component reaction of aldehydes, ethyl acetoacetate, and malononitrile in the presence of ammonia as catalyst at room temperature. The reaction is rapid and clean, and gives the products in high yields.