Process for the preparation of isophoronediamine

US5504254A · kind A · utility

Assignee

• Degussa AG · DE

Inventors

• Thomas Haas · Munster, DE
• Dietrich Arntz · Oberursel, DE
• Dieter Most · Bruchköbel, DE

Key dates

• Filing date: Dec 22, 1994
• Grant date: Apr 2, 1996
• Expiry date: Dec 22, 2014

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C2601/14
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process is disclosed for the continuous preparation of 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophoronediamine) in high yield and high purity from 3-cyano-3,5,5-trimethylcyclohexanone (isophoronenitrile) by aminating hydrogenation with hydrogen and ammonia in the presence of a fixed bed catalyst. The aminating hydrogenation is carried out by allowing a mixture of isophoronenitrile, ammonia and a C.sub.1 -C.sub.3 -alcohol, in the presence of hydrogen, to trickle over a trickle bed reactor provided with a Co and/or Ru fixed bed catalyst, at 3 to 8 MPa and at a temperature of 40.degree. to 150.degree. C., preferably 90 to 130.degree. C., and working up the reaction mixture by distillation. Preferably, a high-boiling by-product fraction, containing a bicyclic amidine, is added to the mixture to be hydrogenated, thereby appreciably increasing the yield.