反应详情

Dissolve 2-chloro-4-trifluoromethylbenzonitrile (405 mg, 1.97 mmol) in anhydrous toluene (7 mL) and cool in a dry ice/ethanol bath. Add diisobutylaluminum hydride (DIBAL) (3.94 mL, 3.94 mmol, 1.0 M in toluene) slowly. Stir 30 min. Warm to room temperature, add acetic acid (2 mL) and wafer (10 mL) and stir for 2 hours. Extract the aqueous layer with ethyl acetate twice. Wash the organic layer with potassium sodium tartrate solution (Rochelle salt) twice. Dry (magnesium sulfate), filter, and concentrate to give a residue. Chromatograph the residue on silica gel eluting with a gradient of 100:0 to 1:1 hexanes:dichloromethane to give 2-chloro-4-trifluoromethylbenzaldehyde (123 mg, 30%). 1H NMR (400 MHz, CDCl3) δ 10.52 (s, 1H), 8.05 (d, 1H, J=8.0 Hz), 7.75 (s, 1H), 7.66 (d, 1H, J=8.0 Hz).

1. temperaturecool in a dry ice/ethanol bath
2. stirringstir for 2 hours
3. extractionExtract the aqueous layer with ethyl acetate twice
4. washWash the organic layer with potassium sodium tartrate solution (Rochelle salt) twice
5. dry with materialDry (magnesium sulfate)
6. filtrationfilter
7. concentrationconcentrate
8. customto give a residue