反应详情

To a suspension of thionicotinamide (30.0 g, 217.1 mmol) in EtOH (400 mL) at room temperature was added ethyl bromopyruvate (90% technical, 30.6 mL, 219 mmol). The reaction mixture was heated to reflux and stirred for 2.5 days. The reaction mixture was cooled to room temperature and the precipitate that formed upon cooling was collected via vacuum filtration. The cake was rinsed twice with hexanes. This solid was added to a separatory funnel containing ethyl acetate and saturated aqueous NaHCO3. The biphasic mixture was separated and the organic layer was washed with brine, dried over MgSO4, filtered, and concentrated in vacuo. The crude product was purified using silica gel chromatography, (0 to 100% ethyl acetate/hexanes) to afford the desired product as a tan solid (24.1 g, 47%): mp 73-75° C.; 1H NMR (300 MHz, CDCl3) δ 9.19 (dd, J=2.6, 1.0 Hz, 1H), 8.69 (dd, J=4.6, 1.6 Hz, 1H), 8.34 (dt, J=7.9, 1.6 Hz, 1H), 8.22 (s, 1H), 7.41 (ddd, J=7.9, 4.6, 1.0 Hz, 1H), 4.47 (q, J=6.9 Hz, 2H), 1.43 (t, J=6.9 Hz, 3H); ESIMS m/z 236.1 (M+2).

1. temperatureThe reaction mixture was heated
2. temperatureto reflux
3. customthe precipitate that formed
4. temperatureupon cooling
5. filtrationwas collected via vacuum filtration
6. washThe cake was rinsed twice with hexanes
7. additionThis solid was added to a separatory funnel
8. additioncontaining ethyl acetate and saturated aqueous NaHCO3
9. customThe biphasic mixture was separated
10. washthe organic layer was washed with brine
11. dry with materialdried over MgSO4
12. filtrationfiltered
13. concentrationconcentrated in vacuo
14. customThe crude product was purified