反应详情

To a suspension of NaH (60% in oil, 1.89 g, 47 mmol) in 20 mL of DMF was added tert-butyl ethyl propanedioate (6.5 g, 34.7 mmol) at room temperature. The mixture was stirred for 30 min. A solution of 2-chloro-5-nitropyridine (5.0 g, 31.5 mmol) in 10 mL of DMF was added. The mixture was stirred at r.t. overnight. The solvent was removed under reduce pressure. Water was added and the mixture was extracted with EtOAc. The combined organic layer was washed with brine, dried over anhydrous Na2SO4, concentrated and the residue was purified by column chromatography with silica gel to give tert-butyl ethyl (5-nitropyridin-2-yl)propanedioate: 1H-NMR (400 MHz, CDCl3) δ 9.39 (s, 1H), 8.51 (d, J=8.8 Hz, 1H), 7.76 (d, J=8.8 Hz, 1H), 5.00 (s, 1H), 4.28 (q, J=7.2 Hz, 2H), 1.49 (s, 9H), 1.31 (t, J=7.2 Hz, 3H).

1. stirringThe mixture was stirred at r.t. overnight
2. customThe solvent was removed
3. additionWater was added
4. extractionthe mixture was extracted with EtOAc
5. washThe combined organic layer was washed with brine
6. dry with materialdried over anhydrous Na2SO4
7. concentrationconcentrated
8. customthe residue was purified by column chromatography with silica gel