Multi component reactions under increased pressure: On the mechanism of formation of pyridazino[5,4,3-de][1,6]naphthyridine derivatives by the reaction of malononitrile, aldehydes and 2-oxoglyoxalarylhydrazones in Q-Tubes

Abstract

Efficient synthesis of phenanthridin-6(5H)-one derivatives 12a-n in a four-component reaction of aldehyde hydrazone, aromatic aldehydes and malononitrile in Q-Tubes is reported. The results showed that the methodology has the advantage of being a one-pot synthesis of tricyclic systems in good yields. Potential routes leading to formation of compounds 12 are discussed. The structures of the synthesized compounds could be unequivocally established via X-ray crystal structure determination and spectroscopic methods.