The invention relates to a method for recovering stable nitroxide radicals, wherein at least part of a reaction mixture consisting of a solid or suspension, or a filtrate or supernatent of a suspension, in which stable nitroxide radicals are present in non-solid form, is subjected to an azeotropic distillation. The invention further relates to a method for the selective oxidation of compounds which contain at least one hydroxyl group, using stable nitroxide radicals as catalyst, wherein the liquid phase of the mixture containing the reaction producsts is subjected to an azeotropic distillation, whereafter the nitroxide radical-containing distillate is recirculated to the reaction vessel.
Heeres, A., Van Doren, H. A., Bleeker, I. P., & Gotleib, K. F. (1996). Method for Recovering or Recirculating Stable Nitroxide Radicals. Smulders, Th., A., H., J.