Cl.[Cl:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[NH:9][NH2:10].[Br:11][C:12]1[CH:13]=[CH:14][C:15]([C:18](=O)[CH2:19][C:20](=O)[C:21]([O:23][CH3:24])=[O:22])=[N:16][CH:17]=1.C([O-])(O)=O.[Na+]>CO.CCOC(C)=O>[Br:11][C:12]1[CH:13]=[CH:14][C:15]([C:18]2[N:9]([C:4]3[CH:5]=[CH:6][CH:7]=[CH:8][C:3]=3[Cl:2])[N:10]=[C:20]([C:21]([O:23][CH3:24])=[O:22])[CH:19]=2)=[N:16][CH:17]=1A mixture of (2-chlorophenyl)hydrazine hydrochloride (1.1 g, 6.1 mmol) and methyl 4-(5-bromopyridin-2-yl)-2,4-dioxobutanoate (1.7 g, 6.0 mmol) in MeOH (30 mL) was divided into two microwave reaction vessels. Each reaction vessel was then heated in the microwave at 120° C. for ten minutes. LC/MS analysis at this time showed the reaction to be essentially complete. The solutions were concentrated under reduced pressure to afford a dark brown semi-solid. This material was taken up in EtOAc and saturated aqueous NaHCO3. The layers were separated and the basic aqueous was extracted with EtOAc (3×). Combined organic extracts were washed with brine, dried over Na2SO4, filtered and concentrated to afford a dark oil. This crude product was purified by flash column chromatography eluting with a gradient from 0% to 100% EtOAc in hexane to afford methyl 5-(5-bromopyridin-2-yl)-1-(2-chlorophenyl)-1H-pyrazole-3-carboxylate (300 mg, 13% yield) as an oil.
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