反应详情

N-methyl-N-methoxylamine hydrochloride (3.41 g, 35 mmol) was dissolved in 140 mL methylene chloride. Triethylamine (14.6 mL, 105 mmol) was added and the reaction mixture was stirred for 10 minutes. Then the reaction mixture was stirred for 16 hours after 5-bromo-2-chloro-benzoic acid 6a (8.24 g, 35 mmol) and bis(2-oxo-3-oxazolidinyl)phosphonic chloride (10.69 g, 42 mmol) were added in turn. Thereafter, the reaction mixture was extracted with ethyl acetate (80 mL×3) after 120 mL water were added. The organic extract was washed with saturated sodium chloride solution (60 mL) and combined, dried over anhydrous magnesium sulfate, and filtered. The filtrate was concentrated under reduced pressure and the resulting residue was purified by silica gel chromatography with elution system B to obtain the title compound 5-bromo-2-chloro-N-methoxy-N-methyl-benzamide 6b (7.50 g, pale yellow solid), yield: 76.9%. MS m/z (ESI): 280.0 [M+1]; 1H NMR (400 MHz, CDCl3): δ 7.46-7.44 (m, 2H), 7.29-7.26 (m, 1H), 3.49 (s, 3H), 3.37 (s, 3H).

1. additionwere added in turn
2. extractionThereafter, the reaction mixture was extracted with ethyl acetate (80 mL×3) after 120 mL water
3. additionwere added
4. extractionThe organic extract
5. washwas washed with saturated sodium chloride solution (60 mL)
6. dry with materialdried over anhydrous magnesium sulfate
7. filtrationfiltered
8. concentrationThe filtrate was concentrated under reduced pressure
9. customthe resulting residue was purified by silica gel chromatography with elution system B