Improved process for the preparation of carbamates

A process for the preparation of a compound of general structure (I)

• wherein
• each of R1 and R2, are equal to or different from each other, and are independently selected from an alkyl group having 1 to 10 carbon atoms, which is optionally substituted by at least one halogen atom, an aryl group or an aralkyl group;
• R3 is selected from an alkyl group having 1 to 36 carbon atoms, which is optionally substituted by at least one halogen atom, an aryl group or an aralkyl group;
• each of R′, R″ and R4, are equal to or different from each other, and are independently selected from H, an alkyl group having 1 to 10 carbon atoms, which is optionally substituted by at least one halogen atom, an aryl group or an aralkyl group;
• n is an integer in the range from 1 to 8,
• which process comprises an oxidative carbonylation reaction of a compound of general structure (II)
• wherein R1, R2, R4, R′, R″ and n have the same meaning as defined here above, with a hydroxyl compound of general formula (III),
• R3-OH (III),
• wherein R3 has the same meaning as defined here above, and in the presence of a catalyst system, wherein said catalyst system comprises
• at least one catalyst of the formula XkYl [compound (XkYl)] wherein X is Cu or a metal selected from metals from the Group VIIIB, Y is a halogen, a salt of an organic acid or a salt of an organic compound;
• and wherein k is an integer 1, 2, 3 or 4 and l is an integer 0, 1, 2, 3 or 4;
• at least one halogen containing promoter effective to promote said reaction.