To a stirred mixture of 2-[4-(5,6-dichloro-2-ethyl-1H-benzimidazol-1-yl)phenyl]ethanol (Example 96, 100 mg, 0.3 mmol), N,O-Bis-tert-butoxycarbonylhydroxylamine (Baillie, L. C.; Batsanov, A.; Bearder, J. R.; Whiting, D. A. J. Chem. Soc. Perkin Trans. 1, 1998, 20, 3471., 140 mg, 0.6 mmol) and triphenylphosphine (158 mg, 0.6 mmol) in THF (10 mL) was added diethyl azodicarboxylate (DEAD) (0.1 mL, 0.6 mmol). The mixture was stirred under nitrogen atmosphere at room temperature for 2.5 h. The solvent was removed and the residue was purified by flash column chromatography on silica gel eluting with hexane/ehtyl acetate (1:1) to afford 174 mg (quant.) of the title compound as yellow amorphous: 1H-NMR (CDCl3) δ 7.84 (1H, s), 7.46 (2H, d, J=8.4 Hz), 7.25 (2H, d, J=8.4 Hz), 7.16 (1H, s), 3.92 (2H, t, J=6.7 Hz), 3.05 (2H, t, J=6.7 Hz), 2.76 (2H, q, J=7.6 Hz), 1.56 (9H, s), 1.46 (9H, s), 1.33 (3H, t, J=7.6 Hz).
