Synthesis of Pyridyl- β -ketophosphonates

In this paper we report a three-stage synthesis of alkyl ethyl 2-oxo-2-(pyridin-2-, -3-and -4-yl)ethylphosphonates (2a-e, 3a-e, 4a-e) starting from commercially-available triethyl phosphite.Triethyl phosphite was first transesterified with alcohols in the presence of sodium catalyst to give the alkyl diethyl phosphites (1b-e) in low to moderate yields.The Claisen condensation between 2lithioalkylphosphonates and ethyl pyridine-2-,-3-and -4-carboxylate, followed by an Arbusov reaction with methyl iodide, gave the final products in moderate yields.The structures of the products were confirmed by 1H-NMR, 13C-NMR, and 31P-NMR.Estimation of the pharmacotherapeutic potential has been accomplished for synthesized compounds on the basis of Prediction of Activity Spectra for Substances (PASS).