title: Study of the Beckmann rearrangement of acetophenone oxime over porous solids by means of solid state NMR spectroscopy.
abstract: The Beckmann rearrangement of acetophenone oxime using zeolite H-beta and silicalite-N as catalysts has been investigated by means of (15)N and (13)C solid state NMR spectroscopy in combination with theoretical calculations. The results obtained show that the oxime is N-protonated at room temperature on the acid sites of zeolite H-beta. At reaction temperatures of 423 K or above, the two isomeric amides, acetanilide and N-methyl benzamide (NMB) are formed, and interact with the Brønsted acid sites of zeolite H-beta through hydrogen bonds. The presence of residual water hydrolyzes the two amides, while larger amounts inhibit the formation of NMB and cause the total hydrolysis of the acetanilide. Over siliceous zeolite silicalite-N, containing silanol nests as active sites, the oxime is adsorbed through hydrogen bonds and only acetanilide is formed at reaction temperatures of 423 K or above. In the presence of water, the reaction starts at 473 K, still being very selective up to 573 K, and the amide is partially hydrolyzed only above this temperature .
authors: Instituto de Tecnología Química, Valencia, Spain.
authors: Ana Belen
authors: AB
authors: Fernandez
authors: Ines
authors: I
authors: Lezcano-Gonzalez
authors: Mercedes
authors: M
authors: Boronat
authors: Teresa
authors: T
authors: Blasco
authors: Avelino
authors: A
authors: Corma
mesh_terms: D000098:Acetophenones / Q000737:chemistry*; D003198:Computer Simulation; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010091:Oximes / Q000737:chemistry*; D016062:Porosity; D017641:Zeolites / Q000737:chemistry
chemical_list: D000098:Acetophenones; D010091:Oximes; D017641:Zeolites; C038699:acetophenone