反应详情

To a solution of 4,5-difluoro-2-nitrobenzoic acid 1a (40.0 g, 196.947 mmol) in anhydrous MeOH (1.0 L), was added concentrated H2SO4 (60.0 mL) and the clear mixture was refluxed for 2 days. Then methanol was removed in vacuo and the residue was partitioned between EtOAc and water. The EtOAc extract was washed with brine, dried over with anhydrous. Na2SO4, and concentrated to yield the methyl 4,5-difluoro-2-nitrobenzoate 1b as a pale yellow solid, 39.71 g (93%).

1. temperaturethe clear mixture was refluxed for 2 days
2. customThen methanol was removed in vacuo
3. customthe residue was partitioned between EtOAc and water
4. extractionThe EtOAc extract
5. washwas washed with brine
6. customdried over with anhydrous
7. concentrationNa2SO4, and concentrated