(Diethylamino)sulfur trifluoride → 7-(1-Fluoro-1-methylethyl)imidazo[1,2-alpha]pyrimidine
反応式
[N:1]1[CH:2]=[CH:3][N:4]2[CH:9]=[CH:8][C:7]([C:10](O)([CH3:12])[CH3:11])=[N:6][C:5]=12.C(N(S(F)(F)[F:20])CC)C>ClCCl>[F:20][C:10]([C:7]1[CH:8]=[CH:9][N:4]2[CH:3]=[CH:2][N:1]=[C:5]2[N:6]=1)([CH3:12])[CH3:11]参加物
4
反応条件
- 温度
- -78 °C
実験手順
To a cooled (−78° C.) suspension of 2-(imidazo[1,2-α]pyrimidin-7-yl)propan-2-ol (1.02 mg, 5.8 mmol) in dichloromethane (25 ml) was added (diethylamino)sulfur trifluoride (1.22 mg, 7.5 mmol) dropwise over 5 min. The mixture was stirred at −78° C. for 40 min then quenched with methanol (1 ml). The mixture was warmed to ambient temperature, made basic with saturated sodium hydrogencarbonate solution (25 ml) and extracted with dichloromethane (2×25 ml). The combined organics were washed with brine (50 ml), dried over anhydrous sodium sulfate and evaporated to dryness. Purification of this material by chromatography on silica eluting with dichloromethane (containing 0.5% conc. ammonia) on a gradient of methanol (1-3%) gave 7-(1-fluoro-1-methylethyl)imidazo[1,2-α]pyrimidine (180 mg, 17%) as a yellow solid: δH (360 MHz, CDCl3) 1.78 (6H, d, J 22), 7.21 (1H, dd, J 7 and 1), 7.54 (1H, d, J 1), 7.79 (1H, d, J 1), 8.45 (1H, d, J 7).