Synthesis of Substituted dihtydro-5H-pyrano[4,-3-b]pyridin-3-carboxamides and -3-carboxylic acids

Optimal conditions were established for the hydrolysis of 2-amino-3-cyanodihydropyranopyridines to give substituted dihydro-5H-pyrano-4,3-b]pyridine-3-carboxylic acids. Two convenient routes also were developed for the synthesis of the 3-carboxamide derivatives of substi-tuted dihydro-5H-pyrano4,3-b]pyridine from the corresponding 2-chlorocyano derivatives.A. L. Mndzhoyan Institute of Fine Organic Chemistry, National Academy of Sciences of the Republic of Armenia, Erevan, 375014. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7. pp. 995–998, July, 1994.Original article submitted February 15, 1994.