Ammoximation of cyclohexanone and hydroxyaromatic ketones over titanium molecular sieves Original Research Article

The liquid phase ammoximation of cyclohexanone, ortho and para-hydroxyacetophenones (2-HAP and 4-HAP) with ammonia and hydrogen peroxide was investigated over titanium-silicalite-1 (TS-1), titanium-aluminum-beta (TiAl-Beta) and Ti-ZSM-48. The ammoximation of 4-HAP over TS-1 gave the corresponding oxime in 100% selectivity at 50% 4-HAP conversion. Under similar conditions, TiAl-Beta gave the oxime in 80% selectivity at 30% 4-HAP conversion. Ti-ZSM-48 afforded 17% 4-HAP conversion and 67% 4-HAP oxime selectivity. The ammoximation of 2-HAP occurred with 80% yield over TS-1 and with 40% yield over TiAl-Beta. Methanol as solvent and large excess of ammonia are preferred to perform ammoximation on TiAl-Beta.