Preparation of caprolactam

US4963672A · kind A · utility

Assignee

• BASF SE

Inventors

• Franz Merger · Bischofswerda, DE
• Rolf Fischer · Heidelberg, DE
• Wolfgang Harder · Weinheim, DE
• Claus-Ulrich Priester · Ludwigshafen, DE
• Uwe Vagt · Speyer, DE

Key dates

• Filing date: Dec 12, 1989
• Grant date: Oct 16, 1990
• Expiry date: Dec 12, 2009

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/52
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Caprolactam is prepared in a process comprising the following steps: PA1 (a) reacting the 5-formylvaleric ester with liquid ammonia as reaction medium and hydrogen in the presence of a ruthenium catalyst in liquid phase at from 80.degree. to 140.degree. C. under a hydrogen partial pressure of from 40 to 100 bar, PA1 (b) replacing the reaction medium ammonia by an aromatic hydrocarbon having a boiling point of from 80.degree. to 240.degree. C. which is liquid under the reaction conditions, PA1 (c) heating the resulting mixture in liquid phase under superatmospheric pressure at 230.degree.-350.degree. C. to form caprolactam, and PA1 (d) isolating caprolactam from the resulting reaction mixture.