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.
Pyridines and fused pyridines are accessible by a combination of a Lewis acid-catalyzed multicomponent reaction and aromatization involving loss of a 2-furylmethyl chain.
A one-pot multicomponent reaction for assembling substituted 4-arylidene imidazolin-5-ones from l-amino acid methyl esters, iso-, isothio- or isoselenocyanates, and α-bromoketones has been discovered.
One-pot multicomponent synthesis of highly substituted pyridines using hydrotalcite as a solid base and reusable catalyst