Manufacture of carbamates

Claim 1

A process for the manufacture of carbamates of the formula ##STR23## where R 1 is an aliphatic, cycloaliphatic or araliphatic radical which may be interrupted by one or more ##STR24## and/or oxygen atoms, R 2 is an aliphatic radical of at least 2 carbon atoms which is optionally interrupted by one or more ##STR25## and/or oxygen atoms, or is ##STR26## where the individual R 3 's may be identical or different and each is a cycloaliphatic, araliphatic or aromatic radical, and n is an integer from 2 to 6, and m is 0 or a positive integer, or R 1 is phenyl, or if m is not less than 1, R 1 is hydrogen ##STR27## wherein alcohols of the formula R.sup.1 --O--R.sup.2 .sub.m OH II where R 1 , R 2 and m have the above meanings except for R' being ##STR28## are reacted with urea in the presence of cation exchangers containing nickel ions, said exchangers having been prepared by exchanging the nickel ions into the performed cation exchangers, said cation exchangers being selected from the group consisting of phenolic resins, polystyrenesulfonic acid resins, bifunctional condensation resins, styrenephosphonic acid resins, styrenephosphinic acid resins, resorcinol resins or aliphatic or aromatic carboxylic acid resins.