Synthesis of Functionalized Pyrano[3,2‐c]pyridines and Their Transformations to 4‐Hydroxy‐3[(1E)‐N‐hydroxyalkanimidoyl]pyridones

Abstract

Reaction of 4‐hydroxy‐6‐methyl‐2(1H)‐pyridones 1a and 4‐hydroxy‐1,6‐dimethyl‐2(1H)‐pyridones 1b with diethyl malonates 2a–e leads to the formation of pyrano[3,2‐c]pyridines 4a–j. Degradation of 4a–i affords the corresponding ketones 6a–i. Condensation of ketones 6a–i with hydroxyl amine or phenyl hydrazine hydrochloride is described.

Keywords:

• ethyl malonates
• 4‐hydroxy‐2‐pyridones
• pyrano[3,2‐c]pyridines

Acknowledgment

The authors thank DANIDA for the financial support to carry out this work at the Faculty of Science, Monoufiya University, through the project “Development of New Drugs against Hepatitis.”