[CH2:1]([O:3][C:4]([C:6]1[N:7]([C:12]2[CH:17]=[CH:16][C:15]([O:18]C)=[CH:14][CH:13]=2)[N:8]=[C:9]([CH3:11])[CH:10]=1)=[O:5])[CH3:2].B(Br)(Br)Br>C(Cl)Cl>[CH2:1]([O:3][C:4]([C:6]1[N:7]([C:12]2[CH:13]=[CH:14][C:15]([OH:18])=[CH:16][CH:17]=2)[N:8]=[C:9]([CH3:11])[CH:10]=1)=[O:5])[CH3:2]To a solution of 2-(4-methoxyphenyl)-5-methyl-2H-pyrazole-3-carboxylic acid ethyl ester (200 mg, 0.768 mmol, Example 10, Step 1) in methylene chloride (10 mL) at −40° C. was added boron tribromide (2.3 mL). The reaction was allowed to stir for 1 hour at −40° C. and for an additional hour while warming to room temperature. The reaction was quenched with ethanol diluted with water and methylene chloride. The organic layer was dried (MgSO4) and concentrated to give 128 mg of the desired product. LC-MS (C13H14N2O3 calculated 246) m/z 247 (M+H).
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