Studies on Nitrile Salts. I. Dimerization of Nitriles Having α-Hydrogen in the Presence of Hydrogen Chloride

Abstract

The compositions and structures of several stable nitrile-HCl salts previously reported were reinvestigated. Most of them have been found to have the composition of 2RC≡N·2HCl and have been identified as N-(α-chloroalkenyl)alkylamidine hydrochlorides (3) by mass and NMR spectra analyses. However, the 2:3 adduct from chloroacetonitrile was confirmed to be N-(α,α,β-trichloroethyl)chloroacetamidine hydrochloride. The scope and limitations of the dimerization reaction of nitriles having α-hydrogen with HCl were studied. Most nitriles having α-hydrogen react with HCl to give N-(α-chloroalkenyl)alkylamidine hydrochlorides (3). Their hydrolysis to diacylamines (4) was also investigated.