No abstract

Consecutive Knoevenagel condensation, Michael addition, cyclization, and Ullmann Csp 2 -N coupling reactions took place in the Domino reaction of o-halogenated benzaldehydes, tert-butyl 2,4-dioxopiperidine-1-carboxylate, and 1H-indazol-6-amine or 3H-benzo[d]imidazol-5-amine catalyzed by CuI. It gave series of fused hexacyclic heterocycles containing naphthyridine, acridine, and pyrazole (imidazole) moieties in one-pot under ligand-free conditions. Graphical abstract H N N NH 2 CHO Br N O O + CuI Cs 2 CO 3 O O N N N N O BOC N N H NH 2 N N N N O BOC Imidazo[4,5,1-de][1,6]naphthyridino[4,3,2-mn]acridine Pyrazolo[4,5,1-de][1,6]naphthyridino[4,3,2-mn]acridine

The reaction of 2‐(4,5‐diphenyl‐1H‐imidazol‐2‐yl)aniline and aromatic aldehyde was treated in ionic liquids under catalyst‐free condition and gave dehydrogenated 5‐aryl‐2,3‐diphenylimidazo[1,2‐c]quinazolines. The same reaction gave un‐aromatized 5‐aryl‐2,3‐diphenyl‐5,6‐dihydroimidazo[1,2‐c]quinazoline derivatives while it was controlled in an inert gas. This procedure approach to imidazo[1,2‐c]quinazolines has the advantages of milder reaction conditions, one‐pot, catalyst free, high yields, and environmentally benign.

The tandem reaction of hydrazide (I) with ketone (II) proceeds in the presence of excess NaHCO3 to give the title products (III) containing three new rings.