STUDIES WITH POLYFUNCTIONALLY SUBSTITUTED HETEROAROMATICS: NEW ROUTES FOR SYNTHESIS OF BENZOAZINES

Pyridazine (I) reacts with dimethyl acetylenedicarboxylate and with N-phenyl-maleimide yielding phthalazine (II) and pyrrolophthalazine (III), respectively. Pyridine IV reacts with benzylidene malononitrile to give compound VI. Compounds VIa-c could be successfully converted into the isoquinolines XIa-c on treatment with acrylonitrile. In contrast to the behavior of arylidene malononitrile, compound IV react with N-phenylmaleimide to yield the pyrroloisoquinoline XIII. Similarly, the reaction of compound IV with each of tetracyanoethylene and dimethyl acetylenedicarboxylate gave compounds XIV and XV respectively.