Synthesis of N,N-dimethyldodecylamine by the catalytic hydrogenation of N,N-dimethyldodecylamide

N,N-dimethyldodecylamine was produced by the catalytic hydrogenation of N,N-dimethyldodecylamide over a Ni/γ-Al2O3 catalyst. During the process, there was a side reaction: the catalytic hydrogenation of N,N-dimethyldodecylamide produced dodecyl alcohol and dimethylamine. Therefore, dimethylamine was introduced into the raw materials, which would suppress the side reaction. The Ni/γ-Al2O3 catalyst obtained from the reduction of the NiO/γ-Al2O3 catalyst in an autoclave had higher surface area and nickel dispersion and the amount of coke was less. Therefore, the catalyst had higher activity and stability. In this case, the hydrogen gas was a raw material and a reducing agent, and reduction of the NiO phase and the hydrogenation reaction were carried out synchronously. Under the conditions of dimethylamine introduction and the Ni/γ-Al2O3 catalyst obtained from the reduction of the NiO/γ-Al2O3 catalyst in the autoclave, the N,N-dimethyldodecylamide conversion, the N,N-dimethyldodecylamine selectivity and yield were 98.0, 99.0 and 97.1 %.