O-Alkylation of hydroxypyridines and derivatives via transient alkyl diazonium species

Abstract

Diazotisation of amines with a nitrite reagent was performed in the presence of hydroxy-pyridines and derivatives to give the alkylation products. The O-alkylation product was isolated from 2-, 3-, 4-hydroxypyridines, 2-hydroxyquinoline and 2-hydroxypyrimidines. In the case of 2-hydropyridines, the N-alkylation product was also observed, with the O-alkylation product being favoured. The reaction conditions were compatible with a variety of functional groups, and namely amino alcohols were successfully reacted to afford hydroxy-substituted products. The distinctive reactivity of dinitrites in comparison to mononitrites is also addressed.