反应详情

2,2-Difluoro-2-(fluorosulfonyl)acetic acid (495 mL, 4.79 mmol) was added dropwise to a solution of ethyl 6-hydroxymethylpyridine-2-carboxylate (800 mg, 4.79 mmol) and CuI (91 mg, 0.479 mmol) in MeCN (10 mL) at room temperature at a rate to maintain the internal temperature <30° C. The mixture was stirred for a further 20 min at room temperature, poured onto brine/water and extracted with EtOAc (×3). The combined extracts were dried (MgSO4), filtered, evaporated and purified by column chromatography (4:1 to 2:1, isohexane:EtOAc) to give the title compound (130 mg, 13%) as a colorless oil; NMR δH (400 MHz, CDCl3) 8.01 (1H, d, J 7.5 Hz), 7.89 (1H, t, J 7.5 Hz), 7.66 (1H, d, J 7.5 Hz), 6.41 (1H, t, J 74.0 Hz), 5.14 (2H, s), 4.49 (2H, q, J 7.0 Hz), 1.44 (3H, t, J 7.0 Hz); (M+H)+ 232.

1. temperatureto maintain the internal temperature <30° C
2. additionpoured onto brine/water
3. extractionextracted with EtOAc (×3)
4. dry with materialThe combined extracts were dried (MgSO4)
5. filtrationfiltered
6. customevaporated
7. custompurified by column chromatography (4:1 to 2:1, isohexane:EtOAc)