Preparation, Use, and Safety of O-Mesitylenesulfonylhydroxylamine

The aminating reagent O-mesitylsulfonylhydroxylamine (MSH) has a known potential hazard since it contains high-energy functional groups in its structure. There are references in the literature that report several incidents involving the use of pure and crystalline MSH. The preparation and safe use of this reagent at kilo scale are described herein.