Patent ID: 7629486

Claim:
A process comprising preparing an amino- and hydroxybenzonitrile of the formula (I) wherein X is at least one amino or hydroxy group, by reacting an amino- or hydroxybenzoic acid of the general formula (II) wherein R is —OH, or NH 2 , and X is as defined above, with ammonia in the presence of a supported catalyst comprising phosphorus at a temperature between 250 and 500° C., wherein preparation step 1) is performed in a reaction gas that is oxygen free and contains ammonia and without an organic solvent and is then followed by an at least two-stage purification step 2) in which 2.1) the gaseous mixture or solid reaction product obtained from preparation step 1) is converted to an aqueous ammonium-containing suspension and 2.2) a) releasing the product present in the solid as an ammonium salt with the aid of a filtration by adding acid or by driving out ammonia and subsequently introducing the acid, or b) releasing the product present in the solid as an ammonium salt by reactive distillation, or c) releasing the product present in the solid as an ammonium salt is performed by an elimination at temperatures of from 0 to 100° C. and in the presence of an organic solvent.