[NH2:1][C:2]1[CH:3]=[C:4]([CH:21]=[CH:22][C:23]=1[NH2:24])[O:5][CH2:6][CH2:7][N:8]1[CH2:13][CH2:12][N:11]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[CH2:10][CH2:9]1.O.[Br].[N:27]#[C:28]C#N>C(O)(=O)C>[NH2:27][C:28]1[NH:24][C:23]2[CH:22]=[CH:21][C:4]([O:5][CH2:6][CH2:7][N:8]3[CH2:13][CH2:12][N:11]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[CH2:10][CH2:9]3)=[CH:3][C:2]=2[N:1]=1A 100 mL flasked was charged of tert-butyl 4-(2-(3,4-diaminophenoxy)ethyl)piperazine-1-carboxylate (1.53 g, 4.54 mmol), water (50 mL) and acetic acid (2 mL) and stirred at room temperature for 15 minutes. The reaction mixture was placed in an ice bath and then charged with cyanogen bromine (0.526 g, 5 mmol) and continued to stir at 0° C. The reaction temperature was allowed to warm to room temperature and it was stirred over night. The reaction was completed as determined by LCMS. The reaction mixture was concentrated under reduced pressure and the resulting residue was dissolved in acetone, dried over anhydrous sodium sulfate, filtered and evaporated under reduced pressure to give 1.7 g of tert-butyl 4-(2-(2-amino-1H-benzo[d]imidazol-5-yloxy)ethyl)piperazine-1-carboxylate as a di-acetate salt as black foam. MS (EI): 362 (MH+).
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