Tetrafluoroboric acid → 2-[7-(5-Bromo-4-fluoro-2-methoxyphenyl)imidazo[1,2-b][1,2,4]triazin-3-yl]propan-2-ol

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Reaction Steps

To a cold (−20° C.) solution of 2-[7-(4-fluoro-2-methoxyphenyl)imidazo[1,2-b][1,2,4]triazin-3-yl]propan-2-ol (0.4 g, 1.32 mmol) in acetonitrile (4 ml) under nitrogen was added tetrafluoroboric acid (54 wt % solution in Et2O, 0.21 ml, 1.59 mmol) and then N-bromosuccinimide (0.28 g, 1.59 mmol) slowly such that the internal temperature remained less than −10° C. After addition the cooling bath was removed and the reaction mixture was allowed to warm to room temperature. Stirring at this temperature continued for 16 h. A 40% aqueous solution of NaHSO3 (10 ml) was added and the reaction mixture extracted with EtOAc (3×50 ml). Organic extracts were washed with water (50 ml), saturated aqueous brine (50 ml), dried (Na2SO4) and concentrated under reduced pressure. The residue was purified by flash chromatography (silica gel, EtOAc) to give a quantitative yield of the title compound: 1H NMR (400 MHz, CDCl3) δ 1.71 (6H, s), 3.47 (1H, s), 3.89 (3H, s), 6.86 (1H, d, J 10.3), 8.21 (1H, d, J 7.9), 8.29 (1H, s), 8.74 (1H, s); MS (ES+) m/z 381, 383 [M+H]+.

Provenance & Evidence