One-pot, three-component synthesis of highly substituted pyridines and 1,4-dihydropyridines by using nanocrystalline magnesium oxide

One pot, three component synthesis of 2-amino-4-aryl-3,5-dicyano-6-sulfanylpyridines and the corresponding 1,4-dihydropyridines are from readily accessible starting materials is described. Simply heating of an ethanolic solution of structurally diverse aldehydes with various thiols and malononitrile in the presence of nanocrystalline magnesium oxide provides the highly substituted pyridine derivatives in moderate to high yields, each representing a privileged medicinal scaffold with their structural motif. After completion of the reaction, the catalyst can be recovered efficiently and reused with constintent activity.