Trifluoroacetic acid → N-(1H-benzimidazol-2-ylmethyl)-N-(5,6,7,8-tetrahydroquinolin-8-yl)-ethane-1,2-diamine

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Reaction Steps

To a solution of 2-{[(2-tert-butoxycarbonylamino-ethyl)-(5,6,7,8-tetrahydro-quinolin-8-yl)-amino]-methyl}-benzoimidazole-1-carboxylic acid tert-butyl ester (0.490 g, 0.94 mmol) in dichloromethane (4 mL) was added trifluoroacetic acid (4 mL). The mixture was stirred at room temperature for 1 h. Sodium hydroxide (2 M, 30 mL) was added and the mixture was extracted with chloroform (3×20 mL). The extracts were dried over Na2SO4 and concentrated. Purification of the crude material by column chromatography on silica gel (90:5:5 CH2Cl2—CH3OH—NH4OH) provided 294 mg (97%) of N1-(1H-benzoimidazol-2-ylmethyl)-N1-(5,6,7,8-tetrahydro-quinolin-8-yl)-ethane-1,2-diamine as a colorless oil. 1H NMR (CDCl3) δ 1.60-1.75 (m, 1 H), 1.87-1.98 (m, 1 H), 2.01 (m, 1 H), 2.22 (m, 1 H), 2.56-2.85 (m, 6 H), 4.03 (m, 1 H), 4.04 (d, J=16.8 Hz, 1 H), 4.17 (d, J=16.8 Hz, 1 H), 7.11-7.21 (m, 3 H), 7.40 (d, J=7.8 Hz, 1 H), 7.56 (brs, 2 H), 8.55 (d, J=4.2 Hz, 1 H).

Provenance & Evidence