[4‐(Acetylamino) phenyl] imidodisulfuryl Difluoride

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Chemistry (Pomona)

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[4‐(Acetylamino) phenyl] imidodisulfuryl Difluoride, S(VI) fluorides, AISF


InChI = 1S/C8H8F2N2O5S2/c1-6(13)11-7-2-4-8(5-3-7)12(18(9,14)15)19(10,16)17/h2-5H,1H3,(H,11,13)


(useful reagent for the fluorosulfurylation of phenols and amines)

  • Alternative Names: AISF, (4-acetamidophenyl)(fluorosulfonyl)sulfamoyl fluoride, N-[4-[bis(fluorosulfonyl)amino]phenyl]-acetamide
  • Physical Data: mp 141.0–143.1°C (dec.).1
  • Solubility: soluble in most organic solvents.
  • Form Supplied in: white or off-white solid (commercially available).1
  • Analysis of Reagent Purity: AISF has been characterized by 1H, 13C, and 19F NMR, HRMS, IR, and X-ray crystallography.
  • Preparative Method: Acetanilide is added dropwise to a refluxing solution of (diacetoxyiodo)benzene and lithium bis(fluorosulfonyl)imide in 1,2-dichloroethane (DCE). When the reaction is complete, it is cooled to room temperature and concentrated under reduced pressure. The crude product is purified via silica gel flash chromatography (45% EtOAc/heptane). The purified product is dissolved in hot MTBE, after which activated charcoal is added, and the suspension is stirred overnight. Filtering results in an off-white solid which is then triturated with MTBE/heptane (1:1) to yield AISF (1) (77%) as a white solid. Alternatively, AISF may be prepared using a chromatography-free procedure. Here, activated charcoal is added to the crude reaction mixture and stirred at room temperature. The solids are removed by filtration, and the solution is concentrated under reduced pressure. To the crude product are added DMSO, water, and brine (10:2:1 mixture), followed by extraction with MTBE (4×). The organic layer is washed with water, then brine, and dried using anhydrous magnesium sulfate. After filtering, the organic layer is diluted with heptane and stirred on an ice bath to yield AISF (1) (60%) as a white solid.1 image(1)
  • Handling, Storage, and Precautions: AISF is a bench-stable solid that can be stored and utilized at room temperature. AISF decomposes at temperatures above its melting point. Therefore, heating above 140 °C should be avoided.