PROCESS FOR IMPROVING THE CATALYTIC ACTIVITY OF CATALYST SYSTEMS FOR REDUCTIVE AMINATION OF ALIPHATIC CYANOALDEHYDES TO ALIPHATIC DIAMINES

摘要

The instant invention provides a process for improving catalytic activity of catalyst systems for reductive amination of aliphatic cyanoaldehydes to aliphatic diamines. The process for improving catalytic activity of catalyst systems for reductive amination of aliphatic cyanoaldehydes to aliphatic diamines comprises the steps of: (1) feeding ammonia, optionally hydrogen, and optionally one or more solvents over one or more heterogeneous metal based catalyst systems having a reduced catalytic activity for a period of greater than 1 hour at a temperature in the range of from 50° C. to 500° C.; wherein said one or more heterogeneous metal based catalyst systems have a yield of less than 90 percent based on the molar conversion of cyanoaldehydes to diamines; and (2) thereby improving the catalytic activity of said one or more heterogeneous metal based catalyst systems.