Beckmann Rearrangement with Improved Atom Economy, Catalyzed by Inexpensive, Reusable, Bronsted Acidic Ionic Liquid
Alina Brzęczek‐Szafran, Karol Erfurt, Małgorzata Swadźba‐Kwaśny, Tomasz Piotrowski, Anna Chrobok
Abstract
Inexpensive protic ionic liquids, synthesized from di- or triamines and excess sulfuric acid, were used as solvents and catalysts for the Beckmann rearrangement. The use of ionic liquids in place of oleum or sulfuric acid allowed the base neutralization step, which is required in the conventional Beckmann rearrangement, to be entirely avoided, thereby dramatically improving the atom economy. Using a biphasic water/organic solvent extraction system, it was possible to recover and reuse the ionic liquid. The proposed method was found applicable for the synthesis of a range of primary and secondary amides.
Topics & Concepts
Beckmann rearrangementIonic liquidOleumChemistrySulfuric acidCatalysisAtom economySolventInorganic chemistryIonic bondingAtom (system on chip)Organic chemistryIonComputer scienceEmbedded systemChemical Synthesis and ReactionsChemical synthesis and alkaloidsAsymmetric Hydrogenation and Catalysis