The thermal decompositions of casbamates. III. Ethyl N,N-dimethylcarbamate and the effect of N-substitution upon the β-elimination

Abstract

Ethyl N,N-dimethylcarbamate thermolyses to, N,N-dimethylamine, carbon dioxide, and ethylene in a homogeneous molecular reaction. First-order rate constants are described in s^-1 units by the equation                           log k = 12.10-(44340±400)/θ where θ = 4.576T. The pattern of substituent effects for N-substitution and values of ΔS^? for several N-substituted carbamates show that ring closure through the carbonyl oxygen is favoured over the alternative cyclization involving the nitrogen atom.