Prepn. of N-alkyl-benzamide(s) - by reaction of benzoic ester with aq. soln. of primary amine so that reaction starts in heterogeneous phase

摘要

Prepn. of N-alkylbenzamides of formula (I) by reaction of a benzoic acid ester of formula (II) with a primary amine of formula (III) is effected at 20-100 (pref. 20-75) deg.C. using an aq. soln. of the amine (III) so that the reaction starts in a heterogeneous phase. In the formulae, R1 and R3 = opt. branched 1-4C alkyl (esp. both Me); and R2 = H or opt. branched 1-4C alkyl (esp. H). ADVANTAGE - The excess of amine recovered by distn. of the reaction prod. can be recycled to the reaction (claimed). The use of gaseous amines is avoided and the extent of hydrolysis of the ester is reduced. The reaction proceeds well even though (II) and (III) may be in the form of an emulsion.