A mixture of compound 35d (77 mg, 0.29 mmol), compound 5e (108 mg, 0.38 mmol) and HATU (165 mg, 0.44 mmol) in Et3N (1 mL) and DMF (3 mL) was stirred for 18 h, and then poured into water (10 mL). The mixture was then extracted with EtOAc (3×). The combined organic extracts were washed with brine (2×), dried over Na2SO4, filtered, and concentrated under reduced pressure. The resultant residue was purified by flash column chromatography, eluting with 5% MeOH/CH2Cl2, to give compound 453 (67 mg). MS m/z (M+H+) 497.1. 1H NMR (CD3OD): δ 7.95 (d, J=2.0 Hz, 1H), 7.8 (d, J=2.0 Hz, 1H), 7.65 (d, J=8.1 Hz, 2H), 7.51 (d, J=8.1 Hz, 2H), 7.25 (t, J=8.0 Hz, 1H), 7.02 (s, 1H), 6.90-6.98 (m, 2H), 5.15 (s, 2H), 4.32-4.45 (m, 2H), 4.15-4.25 (m, 2H), 4.00-4.10 (m, 1H), 3.70-3.82 (br. s, 2H), 2.47 (br. s., 4H).
