反应详情

A 75-mL pressure vessel was charged with 1-bromo-2-iodo-4-(trifluoromethyl)benzene (2.015 g, 5.74 mmol), 1-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (Aldrich, St. Louis, Mo., 1.374 g, 6.60 mmol), potassium phosphate (2.438 g, 11.48 mmol), and PdCl2(dppf)-CH2Cl2 adduct (Strem Chemicals Inc., Newburyport, Mass., 0.469 g, 0.574 mmol). The vessel was flushed with Ar (g), then DMF (19.14 ml) was added. The vial was sealed and placed in an 80° C. oil bath for 2 hours. The mixture was diluted with water and extracted with EtOAc (3×). The combined organic extracts were washed with brine, dried over sodium sulfate, filtered, and concentrated. The residue was chromatographed on an 80 g silica gel column to give 5-(2-bromo-5-(trifluoromethyl)phenyl)-1-methyl-1H-pyrazole (1.001 g, 3.28 mmol) as a yellow solid. [M+H]+=307.0.

1. customThe vessel was flushed with Ar (g)
2. additionDMF (19.14 ml) was added
3. customThe vial was sealed
4. customplaced in an 80° C.
5. customfor 2 hours
6. additionThe mixture was diluted with water
7. extractionextracted with EtOAc (3×)
8. washThe combined organic extracts were washed with brine
9. dry with materialdried over sodium sulfate
10. filtrationfiltered
11. concentrationconcentrated
12. customThe residue was chromatographed on an 80 g silica gel column