Substituent-Oriented Synthesis of Substituted Pyridines/Pyrido[3,2-C]coumarins viaSequential Reactions of α-H and Me/Aryl Substituted Oxime Acetates and 3-Formylchromones

Autor: Bodala, Varaprasad, Podugu, Rajitha Lakshmi, Yettula, Kumari, Kadiri, Sunanda Kumari, Vidavalur, Siddaiah
Zdroj: The Journal of Organic Chemistry; September 2024, Vol. 89 Issue: 18 p12957-12966, 10p
Abstrakt: A facile one pot sequential and highly chemoselective synthesis of substituted pyridines/pyrido[3,2-c]coumarins has been developed from oxime acetates and 3-formylchromones in the presence of FeCl2. This reaction was oriented by different substituents on the α-position (H, methyl/aryl) of oxime acetates. Mechanistic investigations suggested that substituted pyridines were formed via intramolecular aza-Michael addition followed by ring opening, while pyrido[3,2-c]coumarins were formed via intermolecular Michael addition. Besides, anti-TB activity was screened for some of the synthesized pyridines. Among the tested compounds, 3ga, 3ha, 3ja, 3ma, 3ac, 4pa, 4pband 4sbwere found to have good activity with an MIC of 12.5 μg/mL.
Databáze: Supplemental Index