反应详情

温度

86 °C

1-Bromo-3,4,5 trifluorobenzene (5 g, 24 mmol) was added to a slurry of Pd(OAc)2 (0.269 g, 5 mol %), bisdiphenylphosphino-ferrocene (1.0 g, 7 mol %) in anhydrous toluene (50 mL) at rt. Benzophenone hydrazone (4.9 g) was added, stirred for 5 min following by addition of dried cesium acetate (9.33 g) and toluene (40 mL). The flask was removed from a glove box and heated to 86° C. for 72 hours. The reaction was monitored by disappearance of bromotrifluourobenzene by LC (210 nm) or 19F NMR. The reaction mixture was cooled down to room temperature and filtered through a sintered glass funnel. The solvent was removed under the vacuum. The orange solid residue was re-dispersed in ether (15 mL) and hexane (150 mL) and heated up to 58° C., stirred for 20 min. The hot solution was quickly filtered, solid discarded and the solution was allowed to cool to room temperature, stirred for 30 min, then 1 hour at 4° C. The formed slurry was filtered, washed with cold hexane (2×25 mL). Crystals were dried in air then in the vacuum at 80° C. for 1 hour to give 5 g of diphenylmethanone (3,4,5-trifluorophenyl)hydrazone (64% yield) as a yellowish solid.

1. customThe flask was removed from a glove box
2. temperatureThe reaction mixture was cooled down to room temperature
3. filtrationfiltered through a sintered glass funnel
4. customThe solvent was removed under the vacuum
5. additionThe orange solid residue was re-dispersed in ether (15 mL)
6. temperaturehexane (150 mL) and heated up to 58° C.
7. stirringstirred for 20 min
8. filtrationThe hot solution was quickly filtered
9. temperatureto cool to room temperature
10. stirringstirred for 30 min
11. custom1 hour
12. customat 4° C
13. filtrationThe formed slurry was filtered
14. washwashed with cold hexane (2×25 mL)
15. customCrystals were dried in air