Synthetic Access to New Pyridone Derivatives through the Alkylation Reactions of Hydroxypyridines with Epoxides

Abstract

General methods for the preparation of a variety of pyridone and oxypyridine derivatives are described. 2‐,3‐,4‐Hydroxy pyridine and 2‐pyridinemethanol were alkylated with ethylene‐, propylene‐, and stryrene‐oxide and epichlorohydrin in the presence of different Lewis acids as a catalyst. The best yield of 3a was achieved in the presence of CdI2/BF3 · OEt2. The corresponding pyridone derivatives (3a–d, 7a–d) were obtained from the reaction of 2‐and 4‐hydroxypyridine with oxiranes in good yields, whereas oxypyridine derivatives (5a–d, 9a,b) were obtained from reactions of 3‐hydroxypyridine and 2‐pyridinemethanol with oxiranes. Chlorohydrines (3d, 5d, 7d) were easily converted to corresponding epoxy derivatives (10, 11, 12) in basic medium; then amino alcohols (13–17) were obtained from the reaction of these epoxy derivatives with amines.