[Br:1][C:2]1[N:3]=[C:4]([Cl:16])[C:5]([NH:8][NH:9]C(=O)C(F)(F)F)=[N:6][CH:7]=1.Cl.C(O)C.C([O-])([O-])=O.[Na+].[Na+]>O>[Br:1][C:2]1[N:3]=[C:4]([Cl:16])[C:5]([NH:8][NH2:9])=[N:6][CH:7]=1A 250 mL round bottom flask was charged with N′-(5-bromo-3-chloropyrazin-2-yl)-2,2,2-trifluoroacetohydrazide (2.97 g, 9.4 mmol), concentrated HCl (6 mL) and ethanol (60 mL). The resulting mixture was heated at 80° C. for 4 h. The reaction mixture was then allowed to cool to room temperature and neutralized with Na2CO3. It was then diluted with water and extracted with EtOAc (50 mL×3). The combined organic layers were dried over anhydrous Na2SO4 and concentrated in vacuo. The residue was further purified by flash column chromatography on silica gel with 20% EtOAc in petroleum ether, to afford 1.24 g (59%) of the product as a yellow solid.
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