Cl[C:2]1[CH:7]=[CH:6][N:5]=[CH:4][C:3]=1[N+:8]([O-:10])=[O:9].[CH3:11][N:12]1[CH2:17][CH2:16][NH:15][CH2:14][CH2:13]1.CCN(C(C)C)C(C)C.C([O-])(O)=O.[Na+]>O1CCOCC1.CCOC(C)=O>[CH3:11][N:12]1[CH2:17][CH2:16][N:15]([C:2]2[CH:7]=[CH:6][N:5]=[CH:4][C:3]=2[N+:8]([O-:10])=[O:9])[CH2:14][CH2:13]14-chloro-3-nitro-pyridine (2 g, 12.61 mmol) in dioxane (15 mL) was treated with 1-methylpiperazine (1.515 g, 1.678 mL, 15.13 mmol) and DIPEA (2.445 g, 3.295 mL, 18.92 mmol). The mixture was stirred at 80° C. for 1 hour, cooled to RT. The mixture was partioned between EtOAc and an aqueous saturated solution of NaHCO3 (40 ml). Combined organic extract was dried over MgSO4 and concentrated under reduced pressure to give an orange oil which was purified by chromatography on silica eluting with 5-10% MeOH/EtOAc/0.5-1% NH4OH to give 1-methyl-4-(3-nitro-4-pyridyl)piperazine 14 as a deep yellow oil which crystallised on standing. (2.56 g, 11.52 mmol, 91.36%). MS (ES+) 223.4.
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