Organic Reactions under High Pressure: Efficient Multicomponent Synthesis of Novel Tricyclic Pyridazinonaphthyridine Derivatives under High Pressure

Background and Methodology: A series of pyridazino[5,4,3-de][1,6]naphthyridine derivatives of a new ring system (11a-k, 29a,b) were synthesized via novel multicomponent reaction under high pressure from 2-phenylhydrazono derivatives (1a-d), malononitrile and aromatic aldehydes (10a-h) or acetone (28). Conclusion: The structure of reaction products could be established by X-ray crystallography and a mechanism of reaction is proposed. Keywords: Multi component reactions, reactions under pressure, hetero-tricyclic systems, 2- phenylhydrazones, aldehydes, acetone.