Trifluoromethanesulfonic anhydride → 5-Methyl-1-(4-methylbenzyl)-1H-pyrazole-3-carbonitrile

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Reaction Steps

To a mechanically stirred solution of 5-methyl-1-(4-methylbenzyl)-1H-pyrazole-3-carboxamide (Step 1, 200 mg, 0.872 mmol) and N,N-diisopropylethylamine (760 μL, 4.36 mmol) in dichloromethane (10 mL) was added dropwise trifluoromethanesulfonic acid anhydride (266 μL, 1.57 mmol) at 0° C. After stirring for 30 minutes at this temperature, all volatiles were removed in vacuo. Then, in a first purification step, the crude product was subjected to preparative HPLC, followed by a second purification using MPLC (silica, dichloromethane) to afford the title compound in pure form (140 mg, 76%): 1H NMR (400 MHz, CDCl3) δ 7.13 (d, 2H), 7.02 (d, 2H), 6.43 (s, 1H), 5.27 (s, 2H), 2.33 (s, 3H), 2.21 (s, 3H); ES-MS m/z 211 (M)+; HPLC RT (Method J) 4.54 min.

Provenance & Evidence