C(OC([NH:8][CH2:9][CH2:10][NH:11][C:12]1[CH:20]=[CH:19][CH:18]=[C:17]([N+:21]([O-:23])=[O:22])[C:13]=1[C:14]([OH:16])=[O:15])=O)(C)(C)C.Cl>C1COCC1.O1CCOCC1.C(OCC)(=O)C>[NH2:8][CH2:9][CH2:10][NH:11][C:12]1[CH:20]=[CH:19][CH:18]=[C:17]([N+:21]([O-:23])=[O:22])[C:13]=1[C:14]([OH:16])=[O:15]To a stirred solution of 2-(2-tert-butoxycarbonylamino-ethylamino)-6-nitro-benzoic acid (0.22 g, 0.00068 mol) in THF at 0° C. was added 4N HCl in dioxane (0.68 mL). The reaction was stirred at 0° C. for 2 h then warmed to room temperature overnight. The reaction mixture was diluted with ethyl acetate and washed with water. The organic phase was dried over magnesium sulfate, filtered and concentrated in vacuo to give 2-(2-amino-ethylamino)-6-nitro-benzoic acid (0.12, 76% yield). 1H NMR (400 MHz, CDCl3) δ 11.6 (s, 1H), 7.57 (t, 1H, J=7.6 Hz), 7.05 (d, 1H, J=7.8 Hz), 6.80 (d, 1H, J=7.8 Hz), 4.0 (broad s, 3H), 3.63 (m, 2H), 3.07 (m, 2H); MS (m/e) 226 (M+1).
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