ABSTRACT
The reductive alkylation of aromatic amines with aldehydes or ketones in the presence of hydrogen and a hydrogenation catalyst is an excellent process of both laboratory and industrial utility. The importance of side reactions depends on whether your objective is to prepare a compound in the laboratory or to develop a commercial process. The two major side reactions are ketone reduction to the alcohol and ring hydrogenation. Ketone reduction would convert the acetone to isopropyl alcohol. Ring hydrogenation would convert the product, N-isopropylaniline, to its alicyclic analog, N-isopropylcyclohexylamine. The enamine undergoes hydrolysis to cyclohexanone and isopropylamine. These can react in a reductive alkylation to form N-isopropylcyclohexylamine, or the isopropylamine can be reductively alkylated with the starting ketone, acetone, to give diisopropylamine. Also, the cyclohexanone can reduce to cyclohexanol.
