反应详情

温度

80 °C

To a stirred suspension of 2,6-dimethoxy-benzonitrile (0.82 g, 5 mmol) and N-methylhydroxylamine hydrochloride (1.66 g, 20 mmol) in 1:1 water/ethanol (20 mL) was added sodium carbonate (1.05 g, 10 mmol) in small portions and the resulting mixture stirred at 80° C. for 24 h. The reaction mixture was concentrated and the residue was re-dissolved into 1:1 water:ethanol (25 mL). To this solution was added diethyl acetylenedicarboxylate (0.96 mL, 6 mmol) and the resulting mixture stirred for 30 min at room temperature. The reaction mixture was then taken up in ethyl acetate (100 mL), washed successively with water and brine (50 mL each), dried (Na2SO4), filtered and concentrated to give a yellow oil. The crude product was purified on silica gel column (3:7 to 1:1 ethyl acetate/hexanes) to afford the title compound as a viscous yellow (1.5795 g, 83% yield). 1HNMR (500 MHz, CDCl3) δ: 7.32 (1H, t, J=8.24 Hz), 6.55 (2H, d, J=8.24 Hz), 4.38–4.24 (2H, m), 4.20–4.14 (2H, m), 3.80 (6H, s), 3.48 (1H, d, J=16.48 Hz), 3.03 (1H, d, J=16.48 Hz), 3.02 (3H, s), 1.33 (3H, t, J=7.02 Hz), 1.26 (3H, 7.02 Hz). HRMS (ESI) calcd for C18H25N2O7S (M+H): 381.1662; found: 381.1656.

1. concentrationThe reaction mixture was concentrated
2. dissolutionthe residue was re-dissolved into 1:1 water
3. stirringthe resulting mixture stirred for 30 min at room temperature
4. washwashed successively with water and brine (50 mL each)
5. dry with materialdried (Na2SO4)
6. filtrationfiltered
7. concentrationconcentrated
8. customto give a yellow oil
9. customThe crude product was purified on silica gel column (3:7 to 1:1 ethyl acetate/hexanes)