4-Toluenesulfonyl chloride → 6-Fluoro-1-tosylindoline

Participants

Reaction Steps

4-Toluenesulfonyl chloride (460 mg, 2.4 mmol) was slowly added to a solution of 6-fluoro-2,3-dihydro-1H-indole (220 mg, 1.6 mmol) in THF (6 mL) and pyridine (260 μL). The reaction mixture was stirred at room temperature overnight. Upon the completion of the reaction, the mixture was cooled to 0° C., neutralized with aq. sat. NH4Cl (10 mL) and extracted with EtOAc (3×10 mL). The combined extracts were sequentially washed with aq. sat. NH4Cl (3×10 mL), brine (10 mL) and dried (MgSO4). The crude product was concentrated and dried over high vacuum. Chromatography of the residue (EtOAc/hexanes=1/3) gave 283 mg (0.98 mmol) of the title product. Yield: 61%, colorless oil. 1H NMR (300 MHz, CDCl3): δ 7.67 (d, J=8.2 Hz, 2H), 7.35 (dd, J=10.0, 2.3 Hz, 1H), 7.23 (d, J=8.2 Hz, 2H), 6.97 (m, 1H), 6.62 (m, 1H), 3.90 (t, J=8.4 Hz, 2H), 2.84 (t, J=8.4 Hz, 2H), 2.35 (s, 3H) ppm. 13C NMR (75 MHz, CDCl3): δ 162.5 (d, J=241.4 Hz), 144.5, 143.3 (d, J=11.7 Hz), 133.6, 129.8, 127.2, 127.0 (d, J=2.6 Hz), 125.7 (d, J=9.8 Hz), 110.0 (d, J=22.6 Hz), 102.8 (d, J=28.4 Hz), 50.7, 27.1, 21.5 ppm.

Provenance & Evidence