Heterocyclic Synthesis with Nitriles: Synthesis of Some New Thiophene, Pyridazine, Oxazine, Thiopyran, Pyrrole, and Pyrrolo[1,2‐b]pyridazine Derivatives*

Abstract

2‐Phenyl‐1,1,3‐tricyanopropene[α‐(cyanomethyl)benzylidene‐malononitrile] undergoes bromination with N‐bromosuccinimide (NBS) to afford 2‐phenyl‐1,1,3‐tricyano‐3‐bromopropene: [α(bromocyanomethyl)benzylidene malononitrile]. This bromo derivative undergoes reactions with sodium hydrogen sulfide, hydrazine hydrate, phenyl hydrazine, hydroxylamine hydrochloride, ethyl thioglycollate, urea derivatives, and cyanacetohydrazide to afford thiophene, 4H‐pyridazines, 4H‐oxazine and 4H‐thiopyran, N‐substituted pyrrole, and pyrrolo[1,2‐b]pyridazine derivatives respectively. * This work has been presented at the 9th Ibn Sina international conference on pure and applied heterocyclic chemistry, held 11–14 December, 2004 at Sharm El Sheikh, Egypt, and organized by the Egyptian Society of Heterocyclic Chemistry, Conference Book p. 194.