The synthesis of thienopyridines from ortho-halogenated pyridine derivatives; Part 2

Synthetic routes to the ortho-halogenated pyridine derivatives, ethyl 2- and 4-chloro-3-pyridylacetate, ethyl 3-bromo-4-pyridylacetate and ethyl 3-bromo-2-pyridylacetate, which have methylene groups activated by the ester functionality are reported. Reaction of these pyridines with carbon disulfide in the presence of sodium hydride, followed by quenching with iodomethane, results in the formation of the corresponding thienopyridines in moderate yields.