A diamine 2-(3,3,5-trimethylcyclohexyl)propane-1,3-diamine of formula 1 and a process for producing 2-(3,3,5-trimethylcyclohexyl)propane-1,3-diamine by A) reacting isophorone (IP) and malononitrile to afford the intermediate 2-(3,5,5-trimethylcyclohex-2-en-1-ylidene)malononitrile, and B) hydrogenating 2-(3,5,5-trimethylcyclohex-2-en-1-ylidene)malononitrile in the presence of at least one catalyst. In another embodiment, the hydrogenation in step B) of the process is performed at 20-120° C. and at 20-300 bar.