Electrochemical synthesis of 3-phenylcinnamonitrile by reduction of benzophenone in acetonitrile

The electrochemical cyanomethylation of benzophenone in acetonitrile was investigated as an interesting way of synthesizing high yield of 3-phenylcinnamonitrile (55% for 50% of theoretical circulated charge). This synthetic method uses the benzophenone radical-anion as a strong electrogenerated base to abstract a proton from the solvent and obtain the nucleophile -CH2CN. This anion is capable of yielding cyanomethylated products very easily. In our case the reaction of this anion with benzophenone yields 3-phenylcinnamonitrile in a father-son like mechanism. (C) 2003 Elsevier Science B.V. All rights reserved.