tetrabutylammonium bromide-cesium carbonate: new reagent system for the synthesis of substituted pyridines at room temperature

the highly substituted pyridine derivatives are found to exhibit diverse pharmacological activities. they are also emerged as potential medicinal leads in developing therapeutic agents for the treatment of various diseases. in this work, a series of 2-amino-3,5-dicarbonitrile-6-thio-pyridine derivatives have been synthesized at room temperature via one-pot, multi-component reaction of various aromatic aldehydes, malononitrile and thiophenols using catalytic amount of tetrabutylammonium bromide (tbab) and cesium carbonate in methanol. in the present method, the use of thermal condition is avoided. in addition, the advantages such as operational simplicity, economic viability, ecologically benign nature make this protocol a very efficient alternative to the literature methods.