Trifluoromethanesulfonic anhydride → 6-chloro-2-(5-fluoro-1H-indol-2-yl)pyridin-3-yl trifluoromethanesulfonate

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Reaction Steps

To a degassed solution of 6-chloro-2-(5-fluoro-1H-indol-2-yl)pyridin-3-ol (600 mg, 2.28 mmol) and DIPEA (1.0 g, 7.74 mmol) in DCM (10 mL), Tf2O (1.3 g, 4.61 mmol) were added dropwise under N2 at 0° C. The mixture was stirred at RT for 2 hours. The mixture was diluted with water and extracted with DCM. The organic layers were washed with brine, dried over Na2SO4, and concentrated. The mixture was purified by column chromatography (PE:EA=10:1) to give 6-chloro-2-(5-fluoro-1H-indol-2-yl)pyridin-3-yl trifluoromethanesulfonate (700 mg, yield: 77.6%). 1H-NMR (DMSO-d6, 400 MHz) δ 11.91 (br s, 1H), 8.17 (d, J=8.8 Hz, 1H), 7.66 (d, J=8.8 Hz, 1H), 7.51˜7.58 (m, 1H), 7.42˜7.50 (m, 1H), 7.18 (d, J=1.6 Hz, 1H), 7.06˜7.14 (m, 1H). MS (M+H)+: 395/397.

Provenance & Evidence