Cl[C:2]1[CH:7]=[C:6]([NH2:8])[C:5]([N+:9]([O-:11])=[O:10])=[CH:4][N:3]=1.[NH:12]1[CH2:16][CH2:15][CH2:14][CH2:13]1.C(=O)([O-])[O-].[K+].[K+]>C(#N)C>[N+:9]([C:5]1[C:6]([NH2:8])=[CH:7][C:2]([N:12]2[CH2:16][CH2:15][CH2:14][CH2:13]2)=[N:3][CH:4]=1)([O-:11])=[O:10]A 500 mL round bottom flask equipped with a reflux condenser was charged with 2-chloro-5-nitropyridin-4-amine (2.00 g, 11.5 mmol, 1.0 equiv), pyrrolidine (2.86 mL, 34.6 mmol, 3.0 equiv), potassium carbonate (4.78 g, 34.6 mmol, 3.0 equiv) and acetonitrile (50 mL). The mixture was heated at 70° C. overnight under nitrogen then cooled to room temperature. The yellow solids were collected by filtration and washed with acetonitrile, water and hexanes. The solids were dried to obtain the title compound as a bright yellow solid (1.43 g, 1st crop). The solvents from the filtrate were removed and the aqueous was extracted with ethyl acetate. The organic extracts was dried (Na2SO4), filtered and removed in vacuo to obtain additional product as an orange/yellow solid (820 mg, 2nd crop). The 2nd crop of product was triturated with ethyl acetate (3 mL) and then filtered and washed with ethyl acetate (2×1 mL) and diethyl ether (3 mL) to obtain a bright yellow solid (751 mg). The total yield of 5-nitro-2-(pyrrolidin-1-yl)pyridin-4-amine obtained was 2.18 g (91%). m/z (ES+) 209.1 (M+H)+. 1H NMR (400 MHz, DMSO-d6): δ 8.79 (s, 1H), 7.39 (br s, 2H), 5.63 (s, 1H), 3.40 (br s, 4H), 1.93 (br s, 4H).
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