[NH:1]1[CH:5]=[C:4]([C:6]#[N:7])[CH:3]=[N:2]1.CC(C)([O-])C.[K+].[Br:14][C:15]1[CH:22]=[CH:21][CH:20]=[C:19](F)[C:16]=1[CH:17]=[O:18]>CS(C)=O>[Br:14][C:15]1[C:16]([CH:17]=[O:18])=[C:19]([N:1]2[CH:5]=[C:4]([C:6]#[N:7])[CH:3]=[N:2]2)[CH:20]=[CH:21][CH:22]=11H-pyrazole-4-carbonitrile (935 mg, 10.0 mmol, Eq: 1.00) was dissolved in 15 mL of dry DMSO and potassium tert-butoxide (1.19 g, 10.0 mmol, Eq: 1.00) was added. The mixture was stirred at room temperature for 20 minutes and 2-bromo-6-fluorobenzaldehyde (4.08 g, 20.1 mmol, Eq: 2) was added. The mixture was stirred at room temperature overnight and then extracted with ethyl acetate and water. The organic layer was dried and concentrated. The crude material was purified by flash chromatography (silica gel, 40 g, 20% to 40% EtOAc in hexanes) to give 1-(3-bromo-2-formylphenyl)-1H-pyrazole-4-carbonitrile (1.53 g, 55%).
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