T. Caronna, S. Morrocchi, B. Vittimberga
Sep 1, 1990
Citations
0
Influential Citations
4
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
The photoinitiated reactions of 2,4-pyridinedicarbonitrile (1) and benzophenone in neutral, acidic, and basic 3:1 2-propanol-water and the kinetics of disappearance of 1, have been studied. Pyridinyl radical anion forms as an intermediate by an electron transfer. In acidic solution substitution of the cyano group in the 2 position and in the 2 and 4 positions with diphenylmethanol occurs. In neutral medium both substitution at the 2-position and reduction, in which the cyano group at the 4 position is replaced by hydrogen, are observed. In basic solution in which protonation of the radical anion is not likely, only reduction occurs. The rates of formation and relative yields of these products depends on the pH of the solution. A mechanism is discussed.