反应详情

Add trifluoromethanesulfonic anhydride (0.66 mL, 3.94 mmol) to a solution of quinoxalin-5-ol (Yamamoto, T. et al., J. Am. Chem. Soc. 1996, 118, 3930-3936; 500 mg, 3.42 mmol) in pyridine (6.8 mL) at 0° C. Allow the reaction to warm slowly to room temperature over 18 h. Add saturated aqueous sodium bicarbonate solution (100 mL) and extract the mixture with methylene chloride (3×100 mL). Dry the combined organic solutions with sodium sulfate, concentrate in vacuo, and purify by flash column chromatography to provide the subtitled compound (810 mg, 85%) as an off-white solid. MS ESI+ m/e 279 (M+1). 1H NMR (CDCl3): δ 8.85 (m, 2H), 8.18 (m, 1H), 7.84 (m, 1H), 7.63 (m, 1H). TLC (SiO2): Rf0.2 (3:1 hexanes/ethyl acetate).

1. customthe reaction
2. extractionAdd saturated aqueous sodium bicarbonate solution (100 mL) and extract the mixture with methylene chloride (3×100 mL)
3. dry with materialDry the combined organic solutions with sodium sulfate
4. concentrationconcentrate in vacuo
5. custompurify by flash column chromatography