One-step synthesis of pyrido[2,3-d]pyrimidines, amides, and benzoxazolylethylpyrimidine by condensation of substituted 3-(2-phenylpyrimidin-5-yl)propanoic acids with aromatic amines in polyphosphoric acid

摘要

Depending on the reactant structure, reactions of substituted 3-(2-phenylpyrimidin-5-yl)propanoic acids with 2-aminopyridine, p-toluidine, and 2-aminophenol in polyphosphoric acid afforded the corresponding N-(pyridin-2-yl)propanamides, 5-[2-(benzoxazol-2-yl)ethyl]pyrimidine, and pyrido[2,3-d]pyrimidinones.