The spontaneous cyclization of some amino acids

Abstract

In the first part of this work, a study is made of the cyclization of 2-(1-aminoethyl)benzoic acid to the lactam over a wide AlkalinA pH region. The reaction is pH-independent above the pK (9005) of thA amino group up to 0.1J.Vl NaOH, where a a hydroxide ion catalysed reaction starts to become significant. Below pH 12 the reaction is found to be buffer catalysed. The second part of this work is a study of the steric acceleration of the cyclization of o-phenyl acetic and propionic acid derivatives under acidic conditions (0.01 - 1M HCl). Steric acceleration may be expressed in terms of an increase in the entropy of activation.