The Beckmann rearrangement of the relatively bulky cyclododecanone oxime was carried out in batch and fixed-bed continuous reactors. With microporous molecular sieve catalysts, the process is controlled by diffusion within the micropores. Conversion, selectivity, and catalyst life are improved with the use of nanocrystalline materials. A solid acid catalyst formed by nanolayers of zeolite is more active and selective than either a nanocrystalline Beta zeolite or a mesoporous MCM-41 material, and the amount of organic remaining adsorbed on the catalyst after reaction is smaller in the former. Product desorption, activity, selectivity and catalyst life are much improved by using a nonprotic polar solvent and higher reaction temperatures. (c) 2007 Elsevier Inc. All rights reserved.