An efficient substituent dependent synthesis of congested pyridines and pyrimidines

Abstract

An efficient and versatile synthesis of various congested pyridines 3a– h, 6a, b, 8a– n, 10a– g, and 16a, b, and (pyrimidin-4-yl)acetonitriles 13a– g has been delineated by base catalyzed ring transformation of suitably functionalized 2 H-pyran-2-ones 1a– h, 5, 7, and 15 by formamidine acetate 2a, acetamidine hydrochloride 2b, S-methylisothiourea 9a, pyrazol-1-yl-carboxamidine 9b, and arylamidine hydrochloride 12 separately in the presence of powdered KOH in dry DMF.