Acid-catalysed N–alkyl heterolysis of tertiary pyridinecarboxamides and benzamides under mild conditions

Abstract

Tertiary pyridinecarboxamides 1–9 and related benzamides 10–18 bearing a tert-butyl substituent were found to undergo alkyl–nitrogen heterolysis under unusually mild conditions. Accordingly, the corresponding secondary amides 19–33 have been isolated in high yields as the sole reaction product. Through a kinetic study based on pH–rate profiles and activation parameters, we have shown that the alkyl–nitrogen fission involved an initial protonation of the amide group that would concern the oxygen atom.