反应详情

3-Chloro-5-difluoromethoxybenzoic acid (1.8 g, 8 mmol; see step (iii) above) and oxalyl chloride (1.5 g, 11.8 mmol) were dissolved in methylene chloride (50 mL). DMF (2 drops) was added and the reaction mixture was stirred at ambient temperature for 30 minutes. Then, N,O-dimethylhydroxylamine (1 g, 10.2 mmol) and triethylamine (3 g, 30 mmol) were added and after another 10 minutes stirring at ambient temperature, the reaction mixture was concentrated at reduced pressure. The residue was taken up in ether (100 mL) and water (50 mL). After separation, the organic phase was washed with brine, dried over sodium sulphate, filtered and concentrated. This residue was chromatographed on silica (hexane/ethyl acetate 2:1) which gave 2 g, 7.5 mmol (93%) of the sub-title compound.

1. stirringstirring at ambient temperature
2. concentrationthe reaction mixture was concentrated at reduced pressure
3. customAfter separation
4. washthe organic phase was washed with brine
5. dry with materialdried over sodium sulphate
6. filtrationfiltered
7. concentrationconcentrated
8. customThis residue was chromatographed on silica (hexane/ethyl acetate 2:1) which