Patent ID: 8034978

Claim:
A process for preparing N-ethyl-N,N-diisopropyl-amine (Hünig base) by reacting acetaldehyde with hydrogen and diisopropylamine in the presence of a heterogeneous catalyst, wherein the reaction is carried out using a suspended catalyst as heterogeneous catalyst and is carried out in the semibatch mode in which the diisopropylamine as one reactant is placed in the reaction vessel and the acetaldehyde as the other reactant is added during the course of the reaction and the acetaldehyde is added in portions or continuously to the reaction mixture during the course of the reaction as a function of the achieved conversion of the diisopropylamine until a conversion of the diisopropylamine of at least 95% results, and all or part of the catalyst remains in the reaction vessel after the reaction batch and is reused for the next reaction batch.