The reactions of aromatic Schiff bases with dimethyl acetylenedicarboxylate. I. Reaction in an organic solvent

Abstract

Reaction of benzylideneanisidine with dimethyl acetylenedicarboxylate in refluxing xylene/nitrobenzene gave low yields of a bis-adduct, the dihydropyridine (12), and two dehydro adducts-the quinolines (13a) and (14). Anisylideneaniline under similar conditions gave the dihydropyridine (16) and an 'abnormal' bis-adduct. Benzylideneaniline gave only an 'abnormal' bis-adduct.