反应详情

A solution of 2,6-difluoro-3-nitro-benzaldehyde (9.0 g, 48.1 mmol), p-toluenesulfonic acid monohydrate (183 mg, 0.962 mmol), trimethylorthoformate (3.5 ml, 32.4 mmol) and methanol (200 ml) was heated at reflux for 4 hours. The reaction mixture was allowed to cool to room temperature and then concentrated in vacuo. The resultant residue was dissolved in DCM (250 mL) and washed with a mixture of water (200 mL) and saturated NaHCO3 solution (50 mL). The organic layer was dried (Na2SO4) and concentrated in vacuo to yield the title compound (10.83 g, 97%). 1H NMR (DMSO-d6, 300 MHz): 8.28 (1 H, ddd, J=9.34, 8.48, 5.51 Hz), 7.39 (1 H, td, J=9.34, 1.81 Hz), 5.66 (1 H, s), 3.40 (6 H, s).

1. temperatureat reflux for 4 hours
2. concentrationconcentrated in vacuo
3. dissolutionThe resultant residue was dissolved in DCM (250 mL)
4. washwashed with a mixture of water (200 mL) and saturated NaHCO3 solution (50 mL)
5. dry with materialThe organic layer was dried (Na2SO4)
6. concentrationconcentrated in vacuo