HYDROLYSIS OF ACETONITRILE IN THE PRESENCE OF NBCL5

The mechanism of the hydrolysis of acetonitrile to ammonium ion in the presence of NbCl5 has been investigated. Two possible mechanisms are discussed: metal-assisted (catalysed) hydrolysis and a mechanism based on the addition of alcohol and HCl to the CN triple bond to give init ially an imidate hydrochloride salt, which may undergo further hydroly sis to the ester and ammonium ion (Pinner synthesis). Support for this route came from the spectroscopic identification of the alkoxyimminiu m ion intermediate, CH3C(OCH3) = NH2+. Although the reaction is not ca talysed by Nb, the extent or reaction is strongly related to the amoun t of Nb present. It is concluded that the Pinner reaction is operating with the amount of HCl available for the reaction being controlled by the Nb concentration.