Beckmann rearrangement of cyclohexanone oxime on zeolites

✍ Scribed by Avelino Corma; Hermenegildo Garcia; Jaime Primo; Enrique Sastre

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 522 KB
• Volume: 11
• Category: Article
• ISSN: 0144-2449
• DOI: 10.1016/s0144-2449(05)80010-7

✦ Synopsis

The Beckmann rearrangement of cyclohexanone oxime (1) was carried out in the liquid phase in the presence of a series of acid zeolites (HY-20, HY-50, HY-100, HYD, and HZSM-5) at different reaction temperatures.

Together with e-caprolactam (2). 5-cyano-1-pentene (3), and cyclohexanone (4) were present in the reaction mixtures. From the selectivity curves of 2 and 3, it can be concluded that a Ritter equilibrium between 2 and 3 occurs under our experimental conditions, the direction of the process depending strongly on the hydrophobicity of the catalyst. The influence of the level of Na+ exchange and of the framework Si/AI ratio on the total conversion and the selectivity of 2 reveals that medium and strong acid sites (p& < 0) catalyze the reaction. Finally, no appreciable variations in the specific activity of the catalyst were observed when changing from a tridirectional large pore size sample (Y) to a medium pore size (ZSM-5).