A safe, convenient and efficient method for the preparation of heterocyclic N-oxides using urea hydrogen peroxide

A novel. convenient, and high-yielding method has been developed for the preparation of heterocyclic N-oxides. The reaction uses the urea hydrogen peroxide addition complex as a peroxide Source for the in situ generation of trifluoroperacetic acid. The advantages of this method are easy handling of a stable, solid oxidant; high yields and simple removal of excess reagents and by-products. (C) 2008 Elsevier Ltd. All rights reserved.