Concise Synthesis of Quinolinone Derivatives

A concise and efficient protocol for the synthesis of novel quinolinone derivatives 4 has been established from a intramolecular cyclization of cyanoacetylenaminones 3, which were synthesized by the regio-selective cyanoacylation reaction of beta-enaminones 1 with cyanoacetic acid 2. The reaction was performed in acetonitrile media at 40 degrees C, and piperidine as catalyst. As a result, a novel series of quinolinones 4a similar to 4t were obtained with the yields of 82%similar to 95%. The reaction is particularly attractive due to the following advantages of operational simplicity, atom economy, simple starting materials, and easy purification.