Reaction Steps
Trifluoroacetic acid (0.5 mL) was added to a solution of (R)-t-butyl 2-((R)-4-(1-((R)-1-(2,4-dichlorophenyl)ethyl)-1H-benzo[d]imidazol-6-yl)-2-methylpiperazine-1-carbonyl)pyrrolidine-1-carboxylate (0.072 g, 0.12 mmol) in dichloromethane (1.5 mL) and the resulting solution was stirred at room temperature for 1 h. Excess solvent was removed in vacuo, and the residue was diluted with dichloromethane (10 mL). The organic layer was neutralized with saturated aqueous sodium bicarbonate, and the aqueous layer was further extracted with dichloromethane (2×15 mL). The combined organic layers were dried (Na2SO4), filtered, and concentrated in vacuo. The crude product was purified by reverse phase HPLC (C18 column, acetonitrile-H2O with 0.1% TFA as eluent) to give the product as a white solid (0.007 g, 0.014 mmol, 12%). 1H NMR (400 MHz, CDCl3) δ 8.02 (s, 1 H), 7.66 (d, J=8.8 Hz, 1 H), 7.45 (d, J=1.6 Hz, 1 H), 7.14 (dd, J=1.6, 8.4 Hz, 1 H), 6.93 (d, J=8.4 Hz, 1 H), 6.85 (d, J=8.4 Hz, 1 H), 6.50 (d, J=2.0 Hz, 1 H), 5.89 (q, J=6.8 Hz, 1 H), 4.86-4.80 (m, 1 H), 4.56-4.85 (m, 1 H), 4.28-4.25 (m, 1 H), 3.99-3.94 (m, 1 H), 3.86-3.82 (m, 1 H), 3.73-3.70 (m, 1 H), 3.56-3.50 (m, 1 H), 3.44-3.31 (m, 2 H), 3.20-3.17 (m, 1 H), 2.86-2.81 (m, 2 H), 2.71-2.66 (m, 1 H), 2.16-2.06 (m, 1 H), 1.96 (d, J=6.8 Hz, 3 H), 1.48-1.25 (m, 3 H); MS: (ES) m/z calculated for C25H30Cl2N5O [M+H]+ 486.2, found 486.4
