: Synthesis and Reactions of Some New . Heterocyclic Compounds Related to Pyridine Derivatives

Abstract

The present work was planned to synthesize some new pentasubstituted pyridines and related thieno[2,3-b]pyridines, as new compounds in this field, of anticipated biological and medicinal importance. Also, the reaction of the latter compounds with a variety of reagents to produce other derivatives of pyridine and thieno[2,3-b]pyridine as well as their condensed heterocyclic systems are hereby included. Moreover, some of the synthesized compounds were tested in-vitro for their antimicrobial activities.

Our approach to the synthesis of the target compounds started from the reaction of arylmethylenecyanothioacetamides (81a-c) with acetylacetone, which gave a mixture of dihydrothio­ xopyridines 85a-c and the corresponding tetrahydrothioxo­ pyridines 86a-c. Dehydrogenation of 86a-c to afford 85a-c was achieved by heating in pyridine (Scheme 1).

5-Acetyl-4-aryl-3-cyano-6-methylpyridine-2(1H)-thiones (85a-c) were employed as starting materials for the target compounds.