Evidence for Two Competing Mechanisms in Regeneration of 2-(2,4-Dinitrobenzyl)pyridine from its Enamine Tautomer

Kinetic effects of pressure on the title reaction were studied. The reaction was insensitive to a change in pressure at 0.1 MPa, however, it was accelerated by an increase in pressure at P > 100 MPa, showing the existence of two reaction routes with and without solvent participation. Viscosity-induced retardations observed in highly viscous media supported intervention of solvent molecules at high pressures.