反应详情

温度

-78 °C

3,5-Bis(trifluoromethyl)anisaldehyde (prepared as in Sui and Macielag, Synth. Commun. 1997, 27, 3581-3590, which is expressly incorporated by reference herein; 2.0 grams (g), 7.7 millimoles (mmol)) was dissolved in dry dichloromethane (CH2Cl2; 15 milliliters (mL)), cooled to −78° C. and treated in portions with boron tribromide (BBr3, 1 M solution in CH2Cl2; 8.0 mL, 8.0 mmol). The mixture was stirred and allowed to warm to 25° C. After 20 hours (h), the mixture was cooled to −40° C., carefully treated with H2O (10 mL) and warmed to room temperature. The separated organic phase was washed with water (H2O; 10 mL), saturated (satd) sodium chloride (NaCl) solution (5 mL), dried over sodium sulfate (Na2SO4) and evaporated. The residue was purified by silica gel chromatography with a 0 to 20% gradient of ethyl acetate (EtOAc) in hexane to give the purified aldehyde (1.4 g, 70%) as an oil: 1H NMR (400 MHz, CDCl3) δ 12.05 (s, 1H), 10.02 (s, 1H), 8.07 (s, 2H). EIMS m/z 258.

1. temperatureto warm to 25° C
2. temperaturethe mixture was cooled to −40° C.
3. temperaturewarmed to room temperature
4. washThe separated organic phase was washed with water (H2O; 10 mL), saturated (satd) sodium chloride (NaCl) solution (5 mL)
5. dry with materialdried over sodium sulfate (Na2SO4)
6. customevaporated
7. customThe residue was purified by silica gel chromatography with a 0 to 20% gradient of ethyl acetate (EtOAc) in hexane