The invention providess a process for carbonylating a nitrogen-containing organic compound, selected from the group consisting of nitro, nitroso, azo, and azoxy compounds, by reacting said nitrogen-containing organic compound, with carbon monoxide, wherein the improvement comprises the step of:(a) reacting said nitrogen-containing compound with carbon monoxide, in the presence of a primary amine and a catalyst, essentially free of redox active metal components selected from the group consisting of rhodium and ruthenium.