Kinetics of the Reaction of α-Chloro Aliphatic Acids with Aqueous Ammonia

The kinetics of the reaction of α-chloro aliphatic acids (CAA’s) with aqueous ammonia to form the corresponding α-amino acids and α-hydroxy acids have been studied by measuring the produced chloride ion. The observed rate for CAA’s having COOH on a s-C (s-CAA’s) is expressed as: v=(k1+k2[NH3]ex)[CAA], while the rate for CAA having COOH on a t-C (t-CAA): v=k1[CAA], These results together with previous observations indicate that the mechanism changes with substrate, i.e., pure SN2 type for chloroacetic acid to pure SN1 type for α-chloroisobutyric acid. The exclusion of α-lactone mechanism and the effect of carboxylato group are discussed. The reactivity of ammonia toward α-chloro aliphatic acids is as twice as that of hydroxide ion.