Different methods for the synthesis of pyridine derivatives as well as the chemical reactivity profiles and structures of these substances are reviewed. The utility of these compounds as precursors is emphasized in the synthesis of many heterocycles that are pharmacologically active organic compounds and agrochemicals. This review results from a literature survey containing some synthetic methods and applications of pyridine derivatives.

A novel 2-ethoxycarbonyl methylidine-4,5-dihydo-4-oxo-5-arylmethylidine-1,3-thiazole derivatives (2a-c) are obtained via the reaction of 4-thiazolinone derivative (1) with different aromatic aldehydes. Cyclization of 4-thiazolidinone derivatives (2a-c) with various αcyanocinnamonitriles afforded the corresponding thiazolopyridine derivatives (5a-r). Thiazolopyridine derivatives (5a,b) are refluxed with acetic anhydride, and gave N,Ndiacetyl amino derivatives (8a,b).