反应详情

A solution of 2-fluoro-1,4-diiodo-benzene (804 mg, 2.31 mmol) in tetrahydrofuran (8 mL) was cooled to −78° C. (external) and a 2.0 M solution of isopropylmagnesium chloride in tetrahydrofuran (1.44 mL, 2.89 mmol) added via syringe. The resulting mixture was stirred for 30 minutes while allowing the temperature of the cooling bath to rise to −50° C. The reaction mixture was then immersed in an ice/water bath and anhydrous N,N-dimethylformamide (425 μL, 5.78 mmol) was added by syringe to the reaction mixture. The reaction was stirred at 0° C. for 10 minutes, then at room temperature for 5 minutes. Thin layer chromatography (TLC) indicated the reaction to be complete. The mixture was diluted with saturated aqueous ammonium chloride solution (8 mL) and extracted with diethylether (2×20 mL). The combined organic layers were dried over sodium sulfate and concentrated in vacuo. The resulting residue was purified by chromatography over silica gel gradient eluted with 0 to 15% v/v ethyl acetate/hexanes to give 2-fluoro-4-iodo-benzaldehyde as a fluffy-white solid (389 mg, 67%).

1. customto rise to −50° C
2. customThe reaction mixture was then immersed in an ice/water bath
3. stirringThe reaction was stirred at 0° C. for 10 minutes
4. waitat room temperature for 5 minutes
5. customthe reaction
6. extractionextracted with diethylether (2×20 mL)
7. dry with materialThe combined organic layers were dried over sodium sulfate
8. concentrationconcentrated in vacuo
9. customThe resulting residue was purified by chromatography over silica gel gradient
10. washeluted with 0 to 15% v/v ethyl acetate/hexanes