反应详情

温度

140 °C

To a solution of ethyl 3,4-difluorobenzoate (1.5 g) in N,N-dimethylformamide (12 mL) is added 2-methylimidazole (1.3 g) and K2CO3 (2.2 g) and the mixture is heated at 140° C. in a microwave oven for 1 h. After cooling to room temperature, water and ethyl acetate are added and the organic layer is dried (MgSO4) and concentrated. The residue is purified by chromatography (ethyl acetate/hexane 0:1→1:0). The ester is dissolved in methanol (30 mL) and 4 M aqueous NaOH (3 mL) is added and the mixture is stirred at room temperature for 1 h. The mixture is neutralized with 6 M aqueous HCl, concentrated and then acidified with 6 M aqueous HCl. The precipitate is filtered off washing with a small amount of water and dried by suction to give the title compound.

1. temperatureAfter cooling to room temperature
2. dry with materialthe organic layer is dried (MgSO4)
3. concentrationconcentrated
4. customThe residue is purified by chromatography (ethyl acetate/hexane 0:1→1:0)
5. dissolutionThe ester is dissolved in methanol (30 mL)
6. addition4 M aqueous NaOH (3 mL) is added
7. concentrationconcentrated
8. filtrationThe precipitate is filtered off
9. washwashing with a small amount of water
10. customdried by suction