[CH3:1][S:2][C:3]1[NH:7][N:6]=[C:5]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)[CH:4]=1.[I-:14].[Na+].II.C([O-])([O-])=O.[K+].[K+]>C1COCC1.O>[I:14][C:4]1[C:5]([C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][CH:13]=2)=[N:6][NH:7][C:3]=1[S:2][CH3:1]To a solution of 5-(methylthio)-3-phenyl-1H-pyrazole (1.5 g, 7.88 mmol) in THF (20 mL) and water (20 mL), were added sodium iodide (1.182 g, 7.88 mmol), iodine (3.00 g, 11.83 mmol), and K2CO3 (1.634 g, 11.83 mmol) at room temperature. The reaction was warmed to 100° C. and stirred for 2 h. The reaction was quenched with 2.0 M aqueous sodium thiosulfite and concentrated under reduced pressure. The mixture was extracted with ethyl acetate and washed with NaHCO3 solution. The organic extracts were dried over MgSO4 and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to give the title compound (2.35 g). LCMS m/z=317.02 [M+H]+; 1H NMR (400 MHz, DMSO-d6) δ ppm 2.43 (s, 3H), 7.43-7.79 (m, 5H), 13.5 (s, 1H).
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