Patent ID: 7884121

Claim:
A process for the preparation of an aminoalkyl phenyl carbamate compound of formula 1, wherein R 1 and R 2 independently are hydrogen or C 1-6 alkyl; R 3 and R 4 are the same or different and each is a lower alkyl; or R 3 and R 4 together with the nitrogen to which they are attached form a cyclic moiety of a three to eight-member ring, with or without a hetero atom; R 5 and R 6 independently are hydrogen, linear, branched or cyclic C 1 - 6 alkyl, allyl, propargyl or benzyl; or R 5 and R 6 together with the nitrogen to which they are attached form a cyclic moiety of three to eight member ring, with or without a hetero atom; the carbon center marked with “*” is racemic or enantiomerically enriched (R)- or (S)- configuration; and pharmaceutically acceptable addition salts thereof comprising: i) converting an amine R 5 R 6 NH to a carbamoylimidazolium salt of formula 3 wherein R 5 and R 6 are as defined above; X − is a counterion and R 7 is an alkyl or aryl group; ii) reacting in a solvent at a controlled reaction temperature the compound of formula 3 with a compound of formula 4, wherein R 1 , R 2 , R 3 , R 4 and “*” are as defined above to give the compound of formula 1; and iii) isolating the compound of formula 1.