反应详情

N,N-diisopropylethylamine (1.10 mL, 6.36 mmol) was added to a stirred solution of 2-bromo-5-chlorobenzoic acid (3-1) (0.500 g, 2.12 mmol), N,O-dimethylhydroxylamine.HCl (0.310 g, 3.18 mmol), and O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (1.21 g, 3.18 mmol) in N,N-dimethylformamide (8.5 mL) at ambient temperature. After 3 h, the reaction mixture was poured into water and extracted three times with ethyl acetate. The combined organic extracts were washed with saturated aqueous sodium bicarbonate, brine, dried (MgSO4) and concentrated in vacuo. Purification of the crude residue by flash chromatography on silica gel (gradient elution; 0-25% ethyl acetate/hexanes as eluent) gave 3-2 (0.56 g) as a colorless solid.

1. customat ambient temperature
2. extractionextracted three times with ethyl acetate
3. washThe combined organic extracts were washed with saturated aqueous sodium bicarbonate, brine
4. dry with materialdried (MgSO4)
5. concentrationconcentrated in vacuo
6. customPurification of the crude residue by flash chromatography on silica gel (gradient elution; 0-25% ethyl acetate/hexanes as eluent)