[C:1](=[O:20])([O:18][CH3:19])[O:2][C:3]1[CH:8]=[C:7]([N+:9]([O-])=O)[C:6]([Br:12])=[CH:5][C:4]=1[CH:13]1[CH2:17][CH2:16][CH2:15][CH2:14]1.[BH4-].[Na+].C(OCC)(=O)C.CCCCCC>CO.Cl[Ni]Cl>[C:1](=[O:20])([O:18][CH3:19])[O:2][C:3]1[CH:8]=[C:7]([NH2:9])[C:6]([Br:12])=[CH:5][C:4]=1[CH:13]1[CH2:17][CH2:16][CH2:15][CH2:14]1
Alternative Procedure: To a solution of 4-bromo-2-cyclopentyl-5-nitrophenyl methyl carbonate (100 mg, 0.29 mmol) and NiCl2 (49 mg, 0.38 mmol) in methanol (1.0 mL) was added NaBH4 (14 mg, 0.38 mmol) portion-wise at 0° C. The reaction was stirred for 5 min then quenched with NaHCO3 and diluted with ethyl acetate. The reaction mixture was filtered through a pad of Celite and the layers separated. The aqueous layer was re-extracted with ethyl acetate and the combined organic extracts were dried over Na2SO4, filtered and concentrated. Silica gel chromatography (10% ethyl acetate/hexane) provided 5-amino-4-bromo-2-cyclopentylphenyl methyl carbonate (49 mg, 54% yield).
Wird geladen…
