Reaction Steps
A solution of 3,5-dimethyl-1-(3-(2′-nitrobiphenyl-4-yloxy)phenyl)-1H-pyrazole 3 (2.19 g, 5.68 mmol, 1.0 eq) and PPh3 (4.47 g, 17.04 mmol, 3.0 eq) in 1,2-dichlorobenzene (30 mL) was refluxed (175-185° C.) for 24 hours, then cooled, and the solvent was removed by distillation under high vacuum. The residue was purified through column chromatography on silica gel using hexane/ethyl acetate (10:1-5:1) as an eluent to obtain the desired product as a white solid (1.83 g in 92% yield). 1H NMR (DMSO-d6, 400 MHz): δ 2.11 (s, 3H), 2.28 (s, 3H), 6.02 (s, 1H), 6.92 (dd, J=8.4, 2.0 Hz, 1H), 7.05 (dd, J=8.4, 2.4 Hz, 1H), 7.10 (t, J=2.0 Hz, 1H), 7.13-7.16 (m, 2H), 7.22-7.25 (m, 1H), 7.32-7.36 (m, 1H), 7.46 (d, J=8.0, 1H), 7.47 (t, J=8.4 Hz, 1H), 8.07 (d, J=7.2 Hz, 1H), 8.12 (d, J=8.4 Hz, 1H), 11.25 (s, 1H). 13C NMR (DMSO-d6, 100 MHz): δ 12.30, 13.24, 101.46, 107.52, 110.92, 111.10, 113.37, 116.43, 118.09, 118.87, 119.12, 119.88, 121.50, 122.23, 125.23, 130.36, 139.24, 140.17, 140.68, 140.99, 148.10, 154.44, 158.21.
