No abstract

One‐pot reaction of cyclic 1,3‐diketones, dimethylformamide dimethylacetal (DMFDMA) and 2‐(1H‐benzo[d]imidaz‐2‐yl)acetonitrile was found to be a highly selective process leading to 4‐oxo‐1,2,3,4‐tetrahydrobenzo[4,5]imidazo[1,2‐a]quinolin‐6‐yl cyanides. Optimized reaction conditions using water as solvent at room temperature or under microwave heating allowed high yields of the target products required no additional purification.

The ring-chain tautomerism of 2-imino-2H-pyran derivatives annelated with an aromatic or aliphatic ring and their transformation into corresponding 2-pyridons were studied based on the relative stabilities of two series of model isomers calculated by the DFT method.