反应详情

To a solution of 2-chloro-3-(trifluoromethyl)benzoic acid (1.0 g, 4.5 mmol) in THF (7 mL) was added carbonyl diimidazole (939 mg, 5.8 mmol). After 40 minutes, additional carbonyl diimidazole (200 mg, 1.2 mmol) was added and stirring was continued for 30 minutes. This solution was added dropwise to a separate flask containing hydrazine monohydrate (0.44 mL, 8.9 mmol) in THF (8 mL). After 1 h, 1M HCl was added, and the reaction mixture was extracted with 20% IPA/CHCl3 (×3). The combined organic extracts were washed with brine, dried (Na2SO4), filtered, and concentrated to afford the desired product as a white solid (1.0 g, 94%). MS (ESI): mass calcd. for C8H6ClF3N2O, 238.0; m/z found, 239.0 [M+H]+. 1H NMR (500 MHz, MeOD) δ 7.87 (dd, J=7.9, 1.3 Hz, 1H), 7.72-7.63 (m, 1H), 7.56 (t, J=7.8 Hz, 1H), 7.05 (s, 1H).

1. waitwas continued for 30 minutes
2. additionThis solution was added dropwise to a separate flask
3. waitAfter 1 h
4. extractionthe reaction mixture was extracted with 20% IPA/CHCl3 (×3)
5. washThe combined organic extracts were washed with brine
6. dry with materialdried (Na2SO4)
7. filtrationfiltered
8. concentrationconcentrated