Patent ID: 7939691

Claim:
A process for the preparation of a primary diamine by hydrogenation of a dinitrile compound in the presence of a hydrogenation catalyst, comprising: hydrogenating the dinitrile compound with hydrogen or a hydrogen-containing gas; subjecting the stream E 0 resulting from the hydrogenation medium to a first distillation and recovering a top fraction E 1 which comprises water and the imines present and a bottom fraction Q 1 which comprises the hydrogenated compounds; subjecting the stream Q 1 to a second distillation and recovering a top fraction E 2 which comprises the hydrogenated compounds and a bottom fraction Q 2 which comprises compounds having a higher boiling point than the primary diamine; subjecting the top fraction E 2 to a third distillation and recovering a bottom fraction Q 3 which comprises the hydrogenated compounds and a top fraction E 3 which comprises the compounds having a lower boiling point than that of the diamine compound formed; and subjecting the bottom fraction Q 3 to a fourth distillation and recovering a top fraction E 4 which comprises the pure diamine, and a bottom fraction Q 4 which comprises compounds having a higher boiling point than the primary diamine.