4-bromo-1-phenyl-1H-pyrazole (140 mg, 0.627 mmol), furan-2-ylboronic acid (88.2 mg, 0.941 mmol), Pd(PPh3)4 (70 mg, 0.062 mmol), and Cs2CO3 (400 mg, 1.254 mmol) were combined in toluene-methanol (1:1) (2 ml). The reaction mixture was heated under microwave at 80° C. for 60 minutes. The reaction mixture was then filtered and washed with toluene-ethanol (5 ml), and the filtrate was concentrated. The crude product was column purified using 15-20% ethyl acetate/hexanes, and was then further purified by preparative HPLC to yield the desired 4-(furan-2-yl)-1-phenyl-1H-pyrazole (22 mg, 0.10 mmol 16.7%). The HPLC purity of the final product was 99.72%. LC-MS [M+H] 211 (C13H10N2O+H expected 211.08). The 1H-NMR spectra was in accordance with the chemical structure.
