The thermal decompositions of carbamates. II. Methyl N-methylcarbamate

Abstract

Methyl N-methyloarbamate decomposes in the range 370-422º to give methyl isocyanate and methanol. The reaction is first order in carbamate, and the variation of the rate constants with temperature is given by the equation. k = 10^12.39 exp(-4806O/RT) (s^-l; activation energy in cal mol^-l) Rate constants are unaffected by the addition of isobutene or by increase in the surface to volume ratio of the reaction vessel. The addition of alcohols or amines does not reverse the process. The decomposition is considered to be a homogeneous, unimolecular gas-phase reaction, probably proceeding through a four-centred transition state.