反应详情

温度

60 °C

A round-bottom flask was charged with 1-bromo-2-iodo-4-(trifluoromethyl)benzene (5.00 g, 14.25 mmol), 1-methyl-1h-pyrazole-5-boronic acid pinacol ester (3.41 g, 16.39 mmol), potassium phosphate (6.05 g, 28.5 mmol) and PdCl2(dppf)-CH2Cl2 (1.164 g, 1.425 mmol). The flask was flushed with Ar, and DMF (47.5 ml) was then added. The flask was sealed, heated to 60° C. for 12 h, then stirred at room temperature for 48 h. The mixture was diluted with water and extracted with EtOAc (3×). The combined organics were washed with brine, dried, and concentrated in vacuo. The crude product was purified by chromatography on silica gel (0 to 100% EtOAc/Heptane) to yield 5-(2-bromo-5-(trifluoromethyl)phenyl)-1-methyl-1H-pyrazole (2.956 g, 9.69 mmol, 68.0% yield) as a brown solid. 1H NMR (400 MHz, DMSO-d6) δ=8.06 (td, J=0.7, 8.1 Hz, 1 H), 7.86-7.73 (m, 2 H), 7.53 (d, J=2.0 Hz, 1 H), 6.41 (d, J=2.0 Hz, 1 H), 3.64 (s, 3 H). m/z (ESI) 305.0 (M+H)+.

1. customThe flask was flushed with Ar, and DMF (47.5 ml)
2. additionwas then added
3. customThe flask was sealed
4. additionThe mixture was diluted with water
5. extractionextracted with EtOAc (3×)
6. washThe combined organics were washed with brine
7. customdried
8. concentrationconcentrated in vacuo
9. customThe crude product was purified by chromatography on silica gel (0 to 100% EtOAc/Heptane)