773-64-8

10576-12-2

38202-27-6

Ethyl N-hydroxyacetimidate (2.00 g, 19.4 mmol), N,N-diisopropylethylamine (3.01 g, 23.3 mmol), and 4-dimethylaminopyridine (240 mg, 1.96 mmol) were dissolved in anhydrous dichloromethane (30 mL) and the solution was cooled to 0°C. To the cooled solution was slowly added, with stirring, 2,4,6 -trimethylbenzene-1-sulfonyl chloride (4.66 g, 21.3 mmol) to the cooled solution. The reaction mixture was gradually warmed to room temperature and stirring was continued for 1 hour. Upon completion of the reaction, the reaction was quenched by the addition of water (40 mL) and subsequently extracted with dichloromethane (30 mL, 3 times). The organic layers were combined, dried with anhydrous sodium sulfate and concentrated under reduced pressure to give the crude product. The crude product was purified by silica gel fast column chromatography using a hexane solution of 5% ethyl acetate as eluent to afford ethyl O-(2,4,6-trimethylbenzenesulfonyl)acetohydroxamic acid as a white solid (5.19 g, 94% yield). The product was characterized by 1H NMR (400 MHz, CDCl3), 13C NMR (101 MHz, CDCl3) and HRMS (ESI/TOF), and the data were consistent with the expected structure.