反应详情

A solution of 2,3,4-trifluoro-5-methoxybenzoic acid (Hayashi et al., Bull. Chem. Soc. Jap., 1972; 45(9):2909-2914, 3.443 g, 16.7 mmol) in dichloromethane (100 mL) at 0° C. is treated with oxalyl chloride (7 mL, 80 mmol) followed by N,N-dimethylformamide (4 drops). The mixture is stirred at room temperature for 3.5 hours, concentrated to near dryness, and co-evaporated with benzene. The acid chloride is then diluted with dichloromethane, cooled to 0° C., and treated with absolute ethanol (10 mL, 170 mmol). The resulting solution is stirred at room temperature for 20 hours, poured into saturated NaHCO3 solution, and extracted with dichloromethane. The organic extracts are washed with brine, dried over Na2SO4, filtered, and concentrated under vacuum to afford the title compound (3.785 g). 1H NMR (200 MHz, CDCl3): δ 7.36-7.29 (m, 1H), 4.42 (q, 2H), 3.93 (s, 3H), 1.44 (t, 3H).

1. concentrationconcentrated
2. additionThe acid chloride is then diluted with dichloromethane
3. temperaturecooled to 0° C.
4. stirringThe resulting solution is stirred at room temperature for 20 hours
5. extractionextracted with dichloromethane
6. washThe organic extracts are washed with brine
7. dry with materialdried over Na2SO4
8. filtrationfiltered
9. concentrationconcentrated under vacuum