反应详情

To a solution of 2.5 M n-butyl lithium in hexanes (2 mL, 5.0 mmol) and tetrahydrofuran (20 mL) at −78° C. under an atmosphere of nitrogen was added dropwise tetramethylpiperidine (0.85 mL, 5.0 mmol). The resulting light yellow solution was stirred for approximately 15 minutes, then 1,3-difluoro-5-iodo-benzene (1 g, 4.17 mmol) was added dropwise. This solution was stirred at −78° C. for 1 hour, followed by the addition of acetaldehyde (0.70 mL, 12.5 mmol) via syringe. The reaction mixture was stirred at −78° C. for 10 minutes then allowed to warm to room temperature. TLC indicated the reaction to be complete. The reaction was quenched with saturated aqueous ammonium chloride solution (2 mL), diluted with water (50 mL) and extracted with ethyl acetate (2×30 mL). The combined organic layers were dried over sodium sulfate and concentrated in vacuo. The crude product was purified by chromatography over silica gel gradient eluted with 0 to 25% v/v ethyl acetate/hexanes to give 1-(2,6-difluoro-4-iodo-phenyl)-ethanol (561 mg, 47%).

1. stirringThis solution was stirred at −78° C. for 1 hour
2. stirringThe reaction mixture was stirred at −78° C. for 10 minutes
3. customthe reaction
4. customThe reaction was quenched with saturated aqueous ammonium chloride solution (2 mL)
5. additiondiluted with water (50 mL)
6. extractionextracted with ethyl acetate (2×30 mL)
7. dry with materialThe combined organic layers were dried over sodium sulfate
8. concentrationconcentrated in vacuo
9. customThe crude product was purified by chromatography over silica gel gradient
10. washeluted with 0 to 25% v/v ethyl acetate/hexanes