The release of halide ions from some primary haloalkylamines

Abstract

The kinetics for the release of halide ions from some haloalkylamines and the corresponding haloalkylammonium ions have been investigated in aqueous solutions under different conditions. In basic solutions, the free amines react according to a two-term rate law                         k_obs = k₁+k₂[OH-] and their reactivities are in the order: 2-chloroethylamine ≈ 2-chloro- n-propylamine » 3-chloro-n-propylamine. The products formed are the corresponding iminoalkanes and the possible mechanisms are briefly discussed. In neutral solutions, the haloalkylammonium ions release halide ions by a considerably slower first-order reaction, which is retarded by acid. Since here there is not much difference in reactivity between 2-chloro-n-propylamine and 3-chloro-n-propylamine, the reaction probably involves a single-stage bimolecular attack by the solvent, leading to the formation of aminoalkanols. In both cases, the reactivities of 2-bromoethylamine me greater than those of the corresponding chloro compound.