Reaction of Aminomalononitrile and Benzylic Compounds as a Plausible Route to Phenylalanine

Abstract

As a possible route to phenylalanine, reaction of aminomalononitrile with benzylic compounds was studied. 2-Benzyl-2-aminomalononitrile (3) was obtained in a good yield when aminomalononitrile p-toluenesulfonate (1) was treated with benzyl bromide (2) in THF using triethylamine as a base. The reaction proceeded in the presence of water. Compound 3 was hydrolyzed to afford phenylalanine. The aminomalononitrile route can explain the presence of not only 1 methylene in aromatic amino acids, but also α-hydrogen in all 20 proteinogenic amino acids.