Reaction Steps
Iodotrimethylsilane (2.8 mL, 1 N in methylene chloride) was added dropwise to a -10° C., stirred solution of (R)-2-[2,6-dibromo-4-(6-bromo-benzo[b]naphtho[2,3-d ]thiophen-11-yl)-phenoxy]-4-(1, 3-dioxo-1, 3-dihydro-isoindol-2-yl)-butyric acid, methyl ester (0.770 g, 0.953 mmol) in methylene chloride (14 mL) under a try N2 atmosphere. The solution was allowed to warm to ambient temperature and was stirred overnight. The reaction mixture was quenched, further diluted with water (100 mL), and partitioned between water and methylene chloride (2×75 mL). Methylene chloride extracts were concentrated and triturated with pet. ether. It was then recrystallized from acetic acid to provide the title compound as a grey solid (0.228 g, 52%): mp 215-217° C.: NMR (CDCl3); δ8.35 (d, J=8 Hz, 1 H), 7.89-7.86 (m, 2 H), 7.82 (dd, J=8, 1 Hz, 1 H), 7.76-7.71 (m, 2 H), 7.67(ddd, J=8, 7, 1 Hz, 1 H), 7.63-7.59 (m, 3 H), 7.58 (ddd, J=8, 7, 1 Hz, 1 H), 7.42 (ddd, J=8, 7, 1 Hz, 1 H), 7.20 (ddd, J=8, 7, 1 Hz, 1 H), 6.81(d, J=8 Hz, 1 H), 5.27 (t, J=7 Hz, 1 H, 1 H), 4.12 (m, 2 H), 2.65 (t, J =7 Hz, 2); MS (EI): [M+], 3 bromine isotope pattern, 791 (75%), 793 (98%), 795 (100%), 797 (38%); Anal. Calc. for C34H2OBr3NO5S: C, 51.41, H, 2.54, N, 1.76. Found: C, 51.65, H, 2.37, N, 1.70.
