N-(Trifluoromethylthio)saccharin

Used Chemicals

• N-(Trifluoromethylthio)saccharin [T3713]
• Chlorotrimethylsilane [C0306]
• Methylindole [M0561]
• Dichloromethane

Procedure

To a solution of 1-methylindole (0.125 mL, 1.0 mmol) and N-(trifluoromethylthio)saccharin (0.368 g, 1.30 mmol) in dichloromethane (6 mL) was added chlorotrimethylsilane (0.13 mL, 1,0 mmol). The mixture was stirred at room temperature for 16 hours. The reaction mixture was added to deionized water (20 mL). The white precipitate was filtered and washed with dichloromethane (10 mL). The filtrate was extracted with dichloromethane (20 mL × 2), washed with brine (20 mL), dried over Na2SO4 and filtered. The solvent was removed under reduced pressure. The residue was purified by flash column chromatography (eluent: hexane/ethyl acetate, 99/1→95/5→89/11) to obtain 1-methyl-3-(trifluoromethylthio)indole as a white solid (0.186 g, 80%).

Experimenter’s Comments

The reaction mixture was monitored by TLC (hexane/ethyl acetate = 9/1, Rf = 0.35) and GC.

Analytical Data (1-methyl-3-(trifluoromethylthio)indole)

¹H NMR (400 MHz, CDCl₃); δ 7.84 (s, 3H), 7.79 (d, J =7.80 Hz, 1H), 7.40-7.27(m, 4H)

¹³C NMR (100 MHz, CDCl₃); δ137.15, 136.92, 130.17, 129.38(q, J = 309.6 Hz), 122.90, 121.24, 119.36, 109.85, 92.96, 33.26.

Lead Reference

• N-Trifluoromethylthiosaccharin: An Easily Accessible, Shelf-Stable, Broadly Applicable Trifluoromethylthiolating Reagent
  • C. Xu, B. Ma, Q. Shen, Angew. Chem. Int. Ed. 2014, 53, 9316.