3‐Oxobutanamides in Heterocyclic Synthesis, Synthesis Approaches for new Pyridines, Pyrimidines and their Fused Derivatives

Abstract

Abstract Condensation of 3‐oxobutanamide derivative 1 with DMF‐DMA afforded the thiazolopyrimidines 4 , pyridine derivative 7 and naphthyridines 12 depending on the different reaction conditions. Condensation of 1 with triethylorthoformate afforded ethoxymethylene derivative 3 . The ethoxymethylenes 3 reacted with different nucleophilic reagents to yield 14 , 15 , 20 and 23–25 respectively. Also, it reacted with malononitrile and ethyl cyanoacetate to give pyridine derivatives 28 a,b . Finally, the ethoxymethylenes 3 reacted with β‐naphthol to yield the benzoquinoline derivative 34 .