反应详情

温度

60 °C

To 5-bromo-4-chloro-2-hydroxy-N-methyl-N-o-tolyl-benzamide (2.6 g, 7.3 mmol) in dry DMF (30 mL), was added K2CO3 (2.0 g, 7.6 mmol), followed by addition of t-butyl 4-bromobutyrate (2.0 g, 8.8 mmol). The mixture was heated at 60° C. for 12 hrs and partitioned between ethyl acetate and water. The organic layer was separated, washed with water and brine, and dried over MgSO4. After filtration, concentration and purification by silica gel column chromatography eluting with ethyl acetate in hexanes (3/7) gave 4-[4-bromo-5-chloro-2-(methyl-o-tolyl-carbamoyl)-phenoxy]-butyric acid tert-butyl ester (3.0 g). MS: 496.3 (M+H); tR=2.81 min (method 1).

1. custompartitioned between ethyl acetate and water
2. customThe organic layer was separated
3. washwashed with water and brine
4. dry with materialdried over MgSO4
5. filtrationAfter filtration, concentration and purification by silica gel column chromatography
6. washeluting with ethyl acetate in hexanes (3/7)