Patent ID: 7897801
Filing Date: 2011-03-01
Classification: C07C,Y02P

Abstract:
1. A process for the preparation of dinitrile compounds by hydrocyanation of unsaturated mononitrile compounds in a reaction medium and in the presence of a catalytic system comprising an organometallic complex formed from zero-valent nickel and from a mixture of organophosphorus ligands comprising at least one monodentate organophosphite compound and at least one bidentate organophosphorus compound selected from the group consisting of organophosphites, organophosphinites, organophosphonites and organophosphines, and optionally a promoter, said process comprising a recovery of the catalytic system, and comprising the steps of: a) controlling the concentration of unsaturated nitriles in the reaction medium resulting from the hydrocyanation reaction in order to obtain a concentration by weight of unsaturated nitriles of less than 20% in said medium, b) feeding the said medium to a stage of settling into two upper and lower phases, c) separating the two phases, the lower phase comprising most of the nickel and of the bidentate ligand, and a portion of the monodentate ligand, d) at least partially recycling said lower phase to a hydrocyanation stage, and e) subjecting the upper phase to a liquid/liquid extraction in order to extract the organometallic complex and the organophosphorus compounds present in said upper phase.