Synthesis and Reactions of 3- Cyano 4, 6- Diphenyl (2-Substituted)-Pyridine Likely to Possess Antimicrobial Activity

Heterocycles containing pyridine moiety are representatives of a major structure type in medicinal chemistry and agriculture. Reaction of 2-chloro-4, 6-diphenylpyridine-3-carbonitrile 2 with each of hydrazine hydrate, hydroxylamine and anthranilic acid afforded the corresponding pyrazolo, isoxazolo and quinazolino pyridine derivatives 3, 4 and 5 respectively. While on alkylation of 2-mercapto-4, 6-diphenyl pyridine -3-carbonitrile 7 with each of ethyl chloroacetate and phenacyl bromide followed by cyclisation in presence of NaOH gave the corresponding 4, 6-diphenyl pyridine thienopyridine derivatives 9 and 12. Diazotization of ethyl 3-amino-4, 6-diphenylylthio [2, 3-b]pyridine-2-carboxylate 9 followed by reaction with each of thiourea, guanidine carbonate and hydroxylamine hydrochloride gave the corresponding thienopyridine derivatives 15, 16 and 17 respectively. The biological activity of some newly synthesized compounds has been discussed.