Pyridine → 4-bromo-3-nitro-1-[3-(trifluoromethyl)phenyl]-1H-pyrazole

Participants

Reaction Steps

Pyridine (99%, 0.512 mL, 6.27 mmol) and [3-(trifluoromethyl)phenyl]boronic acid (649 mg, 3.42 mmol) were added to a solution of 4-bromo-3-nitro-1H-pyrazole (596.6 mg, 3.108 mmol) in tetrahydrofuran (9 mL); copper(II) acetate (99%, 855 mg, 4.66 mmol) was then added, and the reaction was stirred for 42 hours. The reaction mixture was filtered through Celite and concentrated in vacuo, then partitioned between EtOAc (5 mL) and water (5 mL). The aqueous layer was extracted with EtOAc (3×5 mL), and the combined organic layers were washed with water (5 mL) and dried over sodium sulfate. After filtration and removal of solvent under reduced pressure, the residue was purified via silica gel chromatography (Gradient: 0% to 20% EtOAc in heptane) to provide C56. The regiochemistry of C56 was assigned based on NOE experiments. Yield: 779 mg, 2.32 mmol, 75%. GCMS m/z 335, 337 (M+). 1H NMR (400 MHz, CDCl3) δ 7.68-7.76 (m, 2H), 7.94-7.98 (m, 1H), 7.99-8.01 (m, 1H), 8.14 (s, 1H).

Provenance & Evidence