[CH:1]([C:3]1[C:4]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[N:5][NH:6][CH:7]=1)=[O:2].F[C:14]1[C:19]([F:20])=[CH:18][CH:17]=[CH:16][N:15]=1.C(=O)([O-])[O-].[K+].[K+].O>CN(C)C=O>[F:20][C:19]1[C:14]([N:6]2[CH:7]=[C:3]([CH:1]=[O:2])[C:4]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[N:5]2)=[N:15][CH:16]=[CH:17][CH:18]=1A mixture of ethyl 4-formyl-1H-pyrazole-3-carboxylate (1.6 g, 9.52 mmol), 2,3-difluorpyridine (1.20 g) and potassium carbonate (1.97 g) in dimethylformamide (8 mL) is heated and stirred at 100° C. for 1.5 h. Then, the reaction mixture is stirred at room temperature overnight. Water is added, and the organic phase is extracted with ethyl acetate, decanted, dried over magnesium sulfate and solvent evaporated under reduced pressure. Crude is purified by normal phase Isco chromatography using ethyl acetate and hexane to give 711 mg of the title compound. MS (m/z): 264 (M+1).
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