A Quinolinone Compound Was Synthesized By A One-pot Photoinduced Decarboxylation Coupling Reaction

Quinolinone and its derivatives are a kind of very important nitrogen-containing heterocyclic compounds,whose skeleton structure is widely found in natural products or active drug molecules.In particular,2-quinolinone compounds have become the focus because of their excellent biological activity,pharmacological activity and comprehensive applications in clinical medicine.Since the first quinolinone antibiotic nalidixic acid was developed and applied in 1962,the research and development of drugs with lead compounds of 2-quinolinone have been the focus of attention.Through literature research,a one-pot synthesis by visible-light-induced decarboxylation coupling/intramolecular cyclization for preparing 4-aryl-2-quinolinone compounds was developed.Initially,the arylamines were used as the starting material to obtain the quinoline compounds through the skraup synthesis method.Then the N-acetyl-1,2,3,4-tetrahydroquinoline compounds were obtained by the follow reduction and acylation reaction.Meanwhile,benzoylformic acids were obtained by oxidation reaction of acetophenone compounds.Finally,4-aryl-2-quinolinone compounds were synthesized by a one-pot reaction system by visible-light-induced decarboxylation coupling/intramolecular cyclization between N-acetyl-1,2,3,4-tetrahydroquinoline as substrates and benzoylformic acid as acylation reagents.Twenty-two 4-aryl-2-quinolinone compounds were synthesized by the optimized reaction route and the structures were characterized and confirmed by high-resolution mass spectrometry,infrared spectroscopy,¹H-NMR and ¹³C-NMR.The mechanism of the reaction was proposed and proved by relevant experiments in this study.The reaction intermediates were successfully captured and characterized,which demonstrating the free radical reaction mechanism.Finally,in order to verify the applicability of the designed route,HBV inhibitor?a hepatitis b virus inhibitor?was successfully synthesized by the designed route.