反应详情

温度

100 °C

To a mixture of 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5-(trifluoromethyl)aniline (500 mg, 1.742 mmol) in 1,4-dioxane (12 mL) and water (3 mL) was added tert-butyl 4-bromo-1H-pyrazole-1-carboxylate (473 mg, 1.916 mmol), PdCl2(dppf) (127 mg, 0.174 mmol) and Cs2CO3 (1135 mg, 3.48 mmol). The mixture was stirred at 100° C. for 16 h under N2. The mixture was filtered and concentrated, which was purified by silica column chromatography (PE/EA=1:1). All fractions found to contain product by TLC (PE/EA=1:1, Rf=0.2) were combined and concentrated. Then the residue was purified by preparative TLC (DCM/MeOH=15:1, Rf=0.6) to yield a yellow solid of 3-(1H-pyrazol-4-yl)-5-(trifluoromethyl)aniline (8 mg, 0.030 mmol, 1.7% yield): 1H NMR (400 MHz, CD3OD) δ 7.93 (s., 2H), 7.08 (s, 1H), 7.06 (s, 1H), 6.78 (s, 1H). ES-LCMS m/z 228.1 (M+H).

1. filtrationThe mixture was filtered
2. concentrationconcentrated
3. customwhich was purified by silica column chromatography (PE/EA=1:1)
4. concentrationconcentrated
5. customThen the residue was purified by preparative TLC (DCM/MeOH=15:1, Rf=0.6)