反应详情

To the crude ethyl 4-(1-(hydroxyimino)-2-methylpropyl)benzoate in a 100-mL round-bottom flask was added acetic acid (8 mL) and zinc dust (1.33 g, 20.3 mmol). The mixture was stirred at rt for 1 h, then filtered through a pad of Celite. The pad was rinsed with ethanol (50 mL). Combined filtrate was concentrated to give a solid. To the solid residue was added ammonium hydroxide (20 mL) and DCM (50 mL). The solution was stirred at rt for 10 min. After separation, the aqueous layer was extracted with DCM (2×50 mL). Combined organic phases were washed with brine, dried (MgSO4), and concentrated to give an oil. Flash column chromatography (EtOAc:hexanes:TEA, 20:80:2 to 100:0:2) afforded ethyl 4-(1-amino-2-methylpropyl)benzoate (0.563 g, 55%) as a clear oil. LC-MS: (FA) ES+ 222; 1H NMR (CDCl3, 300 MHz) δ7.99 (d, J=8.3 Hz, 2H), 7.36 (d, J=8.5 Hz, 2H), 4.37 (q, J=7.2 Hz, 2 μl), 3.68 (d, J=7.0 Hz, 1H), 1.86 (m, 1H), 1.39 (t, J=7.0 Hz, 3H), 0.96 (d, J=7.0 Hz, 3H), 0.77 (d, J=7.0 Hz, 3H).

1. filtrationfiltered through a pad of Celite
2. washThe pad was rinsed with ethanol (50 mL)
3. concentrationCombined filtrate was concentrated
4. customto give a solid
5. stirringThe solution was stirred at rt for 10 min
6. customAfter separation
7. extractionthe aqueous layer was extracted with DCM (2×50 mL)
8. washCombined organic phases were washed with brine
9. dry with materialdried (MgSO4)
10. concentrationconcentrated
11. customto give an oil