反应详情

Add acetyl chloride (8.5 mL, 120 mmol) to absolute ethanol (30 mL) and stir for 1 h. Add 4-methoxyphenylhydrazine hydrochloride (1.74 g, 10 mmol) and N-(4-oxo-cyclohexyl)-isobutyramide (Preparation 2) (1.83 g, 120 mmol) and reflux with stirring for 56 h. Cool to room temperature, dilute with ethyl acetate (100 mL) and wash with sodium bicarbonate solution (2×50 mL), brine, dry (MgSO4), filter and concentrate in vacuo. Dissolve the residue in dichloromethane and pass over a silica pad, eluting with 20% ethyl acetate/dichloromethane to obtain 2.32 g of a solid. Triturate the solid in diethyl ether with a small amount of dichloromethane, filter and dry under house vacuum to obtain 2.14 g (75%) of an off-white solid. MS (ES): m/z 287 (M+1), 285 (M−1); 1H NMR(DMSO-d6): δ 10.52 (s, 1H), 7.83 (d, 1H, J=7.5 Hz), 7.13 (d, 1H, J=8.8 Hz), 6.85 (s, 1H), 6.64 (dd, 1H, J=8.8, 2.2 Hz), 4.02 (m, 1H), 3.75 (m, 3H), 2.90 (dd, 1H, J=15.0, 5.3 Hz), 2.78 (m, 2H), 2.42 (m, 2H), 1.96 (m, 1H), 1.79 (m, 1H), 1.03 (d, 6H, J=6.6 Hz).

1. stirringwith stirring for 56 h
2. washwash with sodium bicarbonate solution (2×50 mL), brine
3. dry with materialdry (MgSO4)
4. filtrationfilter
5. concentrationconcentrate in vacuo
6. dissolutionDissolve the residue in dichloromethane
7. washpass over a silica pad, eluting with 20% ethyl acetate/dichloromethane