Abstract

-oxoanilides in heterocyclic synthesis: A convenient synthetic route to polyfunctionally substituted pyridazines and pyridines

Author(s): Abdel Haleem M.Hussein, Abu-Bubakr A.M.El-Adasy, Mohamed A.M.Gad-Elkareem, Ismail M.Othman

Coupling of N-naphthalen-1-yl-3-oxo-butyramide (1) with equimol of aryldiazonium chloride salts (2) yield the corresponding hydrazone products (3a-d). The arylhydrazones (3a-d) condensed with ethyl cyanoacetate (4a) to give the pyridazinone derivatives (6a-d). Similarly, hydrazones (3a-d) condensedwithmalononitrile (4b) yielding the pyridazinimines (7a-d). The reaction of compound (1) with equimolar amounts ofmalononitrile upon refluxing in ethanolic piperidine afforded compound (10). In contrast to the behavior of compound (1) towards cyano thioacetamide, it reacted with cyanoacetamide (4d) to yield the expected pyridine (14). Condensation of compound (1) with aromatic aldehydes (15) afforded compounds (16a-d). Compound (1) reacted with arylidenemalononitrile (17a-c) under basic conditions yielding (21a-c). Similarly, Compound (1) easily reacted with arylidenecyano thioacetamide (17a-c) to yield the pyridinethione (25a-c). The structure of the synthesized compounds was established from their analytical and spectral data.