Regiospecific introduction of alkyl groups into 4-position of pyridine novel synthesis of 4-substituted pyridines

Regiospecific synthesis of 4-substituted pyridines is attained via alkylation of diisopropyl 1-ethoxycarbonyl-1, 4-dihydropyridine-4-phosphonate followed by treatment with butyllithium. The phosphonate is prepared directly from pyridine in one pot.