反应详情

To a suspension of 4-methyl-2,5-difluorobenzoic acid (comm, 52 g, 0.3 mol) in methanol (1.0 L) was added concentrated sulphuric acid (3 mL) with stirring and the reaction heated to reflux under nitrogen for 18 hours. The reaction was quenched with aqueous sodium bicarbonate solution (10%, 150 mL), concentrated in vacuo and the resulting residue partitioned between EtOAc (800 mL) and water (400 mL). The organic layer was washed with water (250 mL) and brine (100 mL), dried with sodium sulphate and concentrated in vacuo to yield the title compound as a clear oil that solidified on standing (54.7 g, 98%).

1. temperaturethe reaction heated
2. temperatureto reflux under nitrogen for 18 hours
3. customThe reaction was quenched with aqueous sodium bicarbonate solution (10%, 150 mL)
4. concentrationconcentrated in vacuo
5. customthe resulting residue partitioned between EtOAc (800 mL) and water (400 mL)
6. washThe organic layer was washed with water (250 mL) and brine (100 mL)
7. dry with materialdried with sodium sulphate
8. concentrationconcentrated in vacuo