C(Cl)(=O)C.C(O)C.Cl.[CH3:9][O:10][C:11]1[CH:16]=[CH:15][C:14]([NH:17]N)=[CH:13][CH:12]=1.O=[C:20]1[CH2:25][CH2:24][CH:23]([NH:26][C:27](=[O:31])[CH:28]([CH3:30])[CH3:29])[CH2:22][CH2:21]1>C(OCC)(=O)C>[CH3:9][O:10][C:11]1[CH:16]=[C:15]2[C:14](=[CH:13][CH:12]=1)[NH:17][C:20]1[CH2:25][CH2:24][CH:23]([NH:26][C:27](=[O:31])[CH:28]([CH3:29])[CH3:30])[CH2:22][C:21]2=1
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), and brine. Dry the organic portion(MgSO4), filter, and concentrate in vacuo. Dissolve in dichloromethane and pass over a silica pad, eluting with 20% ethyl acetate/dichloromethane. 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),
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