One-Pot Synthesis of Three Types of 2,3-Disubstituted Thienopyridines from Halopyridinyl Ketones

Abstract

This report describes a one-pot synthesis of three types of thienopyridine derivatives from the respective halopyridinyl ketones.Thus, the reaction of 2-bromopyridin-3-yl ketones, derived from 2-bromopyridine, with sodium sulfide followed by successive treatment BrCH 2 EWG's and sodium hydride afforded 2,3-disubstituted thieno[2,3-b]pyridines.Similar one-pot sequences starting from aryl 3-bromopyridin-4-yl ketones and aryl 4-chloropyridin-3-yl ketones could also be readily performed to afford 2,3-disubstituted thieno[2,3-c]pyridines and 2,3-disubstituted thieno[3,2-c]pyridines, respectively.