反应详情

Ammonium chloride (3.58 g, 66.7 mmol in 10 mL water) was added to a solution of ethyl 2-chloro-5-cyano-6-methylnicotinate (1.0 g, 4.4 mmol) in dioxane-THF-DMF (50 mL, 3:1:1), followed by zinc powder (2.3 g, 35.6 mmol) portionwise at room temperature. The reaction mixture was allowed to stir at room temperature for 3 h, diluted with EtOAc, and filtered through a pad of Celite. The clear filtrate of organic layer was washed with H2O and brine, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The crude product was purified by column chromatography (silica 60-120 mesh, eluent 10-15% EtOAc in petroleum ether) to afford ethyl 5-cyano-6-methylnicotinate (230 mg, yield 27%) as a white solid. 1H NMR (400 MHz, CDCl3) δ 9.25 (d, J=2.0 Hz, 1H), 8.49 (d, J=2.0 Hz, 1H), 7.27 (s, 1H), 4.47-4.42 (q, J=7.2 Hz, 2H), 2.86 (s, 3H), 1.45-1.41 (t, J=7.0 Hz, 3H). MS (ESI) m/z: Calculated for C10H10N2O2: 190.07. found: 191.2 (M+H)+.

1. filtrationfiltered through a pad of Celite
2. washThe clear filtrate of organic layer was washed with H2O and brine
3. dry with materialdried over anhydrous Na2SO4
4. concentrationconcentrated under reduced pressure
5. customThe crude product was purified by column chromatography (silica 60-120 mesh, eluent 10-15% EtOAc in petroleum ether)