Preparation of N-alkyl-monosubstituted carbamates

A process for the preparation of an alkyl-N-monosubstituted carbamic acid ester which comprises reacting an aliphatic primary amine having the formula RNH.sub.2 wherein R is a straight or branched chain alkyl group containing from 1 to 18 carbon atoms, with urea and at least a stoichiometric amount of a monohydric aliphatic alcohol, based on the aliphatic amine and, having from 1 to 18 carbon atoms at a temperature in the range of from about 125.degree. C. to 250.degree. C. in the presence of a catalytic amount of a tertiary amine containing from 1 to 18 carbon atoms and selected from the group consisting of trialkylamines wherein the alkyl groups are the same, triphenylamine, n-dodecyldimethylamine, n-tetradecyldimethylamine, n-hexyldecyldimethylamine, n-octyldecyldimethylamine, N,N,N',N'-tetramethylethylenediamine, 1,4-diazabicyclo[2.2.2]octane, 4(N,N-dimethylamino)pyridine, pyridine, 1,5-diazabicyclo[4.3.0]non-5-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene;

• methyldiethylamine, butyldimethylamine and benzyldimethylamine.