US Patent 7179945 High-selective production method of di(aminomethyl)-substituted aromatic compound

A di(aminomethyl)-substituted aromatic compound is produced by a two-stage hydrogenation. In the first stage, an aromatic dinitrile is hydrogenated into a cyano(aminomethyl)-substituted aromatic compound in the presence of a Pd-containing catalyst. The resultant cyano(aminomethyl)-substituted aromatic compound is then hydrogenated in the second stage into the target di(aminomethyl)-substituted aromatic compound in the presence of a Ni- and/or Co-containing catalyst. By the above method, the di(aminomethyl)-substituted aromatic compound is produced in a high selectivity and a sufficiently high yield without reducing the catalyst life.