Patent ID: 7084294
Filing Date: 2006-08-01
Classification: B01J,C07C,Y02P

Abstract:
1. A process for the recovery of a Lewis acid from a reaction mixture (I) which has been obtained in the hydrocyanation of an olefinically unsaturated compound to a nitrile which has a miscibility gap with water under certain pressure and temperature conditions, in the presence of a catalyst system comprising a Lewis acid and a complex compound comprising a phosphorus-containing compound which is suitable as ligand and a central atom which is suitable for the complex compound, which comprises a) removing the complex compound from mixture (I) to give a mixture (II), b) adding water to the mixture (II) and placing the mixture (II) under pressure and temperature conditions such that a phase (III) which has a higher content of water than of the nitrile and a phase (IV) which has a higher content of the nitrile than of water are obtained, where phase (III) has a higher content of the Lewis acid than does phase (IV), c) adding a liquid diluent (V) that  to phase (III) to form a mixture of phase III and liquid diluent V, d) subjecting the mixture of phase (III) and liquid diluent (V) to distillation under the pressure conditions of step c1 or step c2, giving a mixture (VI) which has a higher content of water than of the diluent (V) and a mixture (VII) which has a higher content of the diluent (V) than of water, where the mixture (VII) has a higher content of the Lewis acid than does the mixture (VI), and e) subjecting the mixture (VII) to hydrocyanation of the olefinically unsaturated compound to give the nitrile, in the presence of the catalyst system.