Acetic Anhydride → 2-Acetoxy-4-[4-(9-bromo-2,3-dimethyl-naphtho[2,3-b]thiophen-4-yl)-2-cyclopentyl-phenoxysulfonyl]-benzoic acid

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Reaction Steps

Using 4-[4-(9-Bromo-2,3-dimethyl-naphtho[2,3-b]thiophen-4-yl)-2-cyclopentyl-phenoxysulfonyl]-2-hydroxy-benzoic acid (0.293 g, 0.450 mmol), acetic anhydride (3.6 mL, 38.2 mmol) and magnesium iodide (0.125 g, 0.450 mmol) the tidle compound was prepared according to the procedure in Example 5. Purification on 2% H3PO4 /MeOH treated silica gel, eluting with a 10 & 30% EtOAc/pet. ether step gradient gave 0.245 g (79%) of the title compound as a colorless solid, mp 155-167° C.; 1H NMR (DMSO-d6) δ 1.32-1.38 (m, 2 H), 1.49-1.53 (m, 5 H), 1.58-1.63 (m, 3 H), 1.78-1.80 (m, 1 H), 2.30 (s, 3 H), 2.45 (s, 3 H), 3.00-3.28 (m, 1 H), 7.25-7.29 (m, 2 H), 7.36-7.39 (m, 2 H), 7.50 (t, 1 H), 7.67 (t, 1 H), 7.83 (d, b 1 H), 7.93 (dd, 1 H), 8.19-8.22 (m, 2 H), 13.6-13.8 (br. s, 1 H). mass spectrum (-ESI), m/z 691/693 (M-H). Anal. Calcd. for C34H29BrO7S2.0.3H2O: C, 58.42; H, 4.27 N, 0.00. Found: C, 58.38; H, 4.55 N, 0.10.

Provenance & Evidence