Methanol → 4-(4-Fluoro-phenyl)-3-(4-methanesulfonyl-phenyl)-5-trifluoromethyl-1H-pyrazole

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Reaction Steps

To a solution of the pyrazole from Step 2 (4.0 g, 11.4 mmol) in 150 mL methanol was added a solution of Oxone® (14.0 g, 22.7 mmol) in 50 mL water. After 1 hour the solids were filtered off, washed with ethyl acetate and the filtrate concentrated in vacuo. This mixture was partitioned between ethyl acetate and water, and the organic layer washed with brine, dried over MgSO4 and reconcentrated in vacuo. Recrystallization from chloroform gave 4-(4-fluorophenyl)-3-[4-(methylsulfonyl)phenyl]-5-(trifluoromethyl)-1H-pyrazole (3.98 g, 91%) as a pale yellow solid: mp 219°-220° C. Elemental analysis for C17H12N2F4SO2Calc'd.: C, 53.12, H, 3.15, N, 7.29, S, 8.34. Found: C, 52.85, H, 3.12, N, 7.21, S, 8.61

Provenance & Evidence