The gaseous oxidation of tertiary aliphatic amines. III. N -methyl diethylamine and N -ethyl dimethylamine

Abstract A comparative study of the gaseous oxidation of N- methyl diethylamine and N-ethyl dimethylamine shows that the former compound closely resembles triethylamine in its general behaviour, while the latter compound exhibits a striking similarity to trimethylamine. With both the mixed tertiary amines a reaction occurs which leads to the formation of secondary amine, but which rapidly becomes self-inhibited as oxidation proceeds. Only with N-methyl dimethylamine, however, are substantial amounts of primary amine formed among the products of slow combustion. A possible explanation of this last difference is that only peroxy-radicals derived from tertiary amines containing at least two ethyl groups can, on steric grounds, readily undergo intramolecular attack to yield monoalkylamines. The apparent ease of such a reaction during the oxidation of N-methyl diethylamine and triethylamine may thus account for the marked contrast between the behaviour of these two compounds on the one hand and that of N-ethyl dimethylamine and trimethylamine on the other.