反应详情

An acetic acid solution (10 ml) of methyl N-{4-[2-(4-chlorophenyl)-4-oxo-1-propylbutyl]benzoyl}-β-alaninate, INTERMEDIATE 4, (757 mg, 1.76 mmol), ZnCl2 (3.1 M in AcOH, 1.7 ml, 5.27 mol) and 2-fluoro-4-methylphenylhydrazine hydrochloride (374 mg, 2.1 mmol) was heated at 80° C. for 45 minutes. The solution was concentrated and the residue partitioned between EtOAc and water. The organic phase was washed with water (2×), brine (2×) and dried over Na2SO4. The solution was filtered, concentrated and the residue purified by silica gel chromatography using a hexanes/ethyl acetate gradient to give the title compound. Data for the major diastereomer: 1H NMR (500 MHz, CD3CN): δ 9.11 (s, 1H); 7.54 (d, J=8.2 Hz, 2H); 7.48 (d, J=8.5 Hz, 2H); 7.38 (d, J=8.2 Hz, 2H); 7.30 (d, J=8.4 Hz, 2H); 7.15 (d, J=2.5 Hz, 1H); 7.11 (s, 1H); 7.02-6.97 (m, 1H); 6.59 (d, J=12.3 Hz, 1H); 4.49 (d, 11.6 Hz, 1H); 3.60 (s, 3H); 3.56-3.48 (m, 3H); 2.52 (t, J=6.8 Hz, 2H); 2.32 (s, 3H); 1.49-1.35 (m, 2H); 1.04-0.90 (m, 2H); 0.69 (t, J=7.4 Hz, 3H). LC1=3.94 min. (M+H)=535. Chiral LC1 (1% to 15% EtOH/heptane over 25 min, 15% EtOH/heptane isocratic >25 min) retention time 28.38 minutes. The material also contains ca 2% by area of the enantiomer. Chiral LC1 (1% to 15% EtOH/beptane over 25 min, 15% EtOH/heptane isocratic >25 min) retention time 26.88 minutes.

1. concentrationThe solution was concentrated
2. customthe residue partitioned between EtOAc and water
3. washThe organic phase was washed with water (2×), brine (2×)
4. dry with materialdried over Na2SO4
5. filtrationThe solution was filtered
6. concentrationconcentrated
7. customthe residue purified by silica gel chromatography