Acetic Anhydride → HCID 9895874, compound

Participants

Reaction Steps

A stirred suspension containing 4-[4-(9-bromo-2,3-dimethyl-naphtho[2,3-b]thiophen-4-yl)-2,6-dimethyl-phenoxysulfonyl]-2-hydroxy-benzoic acid (0.350 g, 0.572 mmol), acetic anhydride (4.55 mL) and magnesium iodide (0.159 g, 0.572 mmol) in anhydrous ethyl ether (10.0 mL, 0.05M) was refluxed for 0.5 h. The reaction was cooled to ambient temperature, quenched with H2O (150 mL), extracted with ether and concentrated. The crude product was dissolved in THF:H2O (1:1, 10 mL) and refluxed for 1 h. The reaction was cooled to ambient temperature, diluted with H2O (50 mL) and extracted with ether and EtOAc. The combined organic extracts were concentrated and purified on 2% H3PO4 /MeOH treated silica gel, eluting with a 20 & 25% EtOAc/pet. ether step gradient to give 0.298 g (76%) of the title compound as a white solid; 1H NMR (DMSO-d6) δ 1.58 (s, 3 H), 2.15 (s, 6 H), 2.30 (s, 3 H), 2.45 (s, 3 H), 7.20 (s, 2 H), 7.46-7.54 (m, 2 H), 7.67 (t, 1 H), 7.94 (d, 1 H), 8.05 (dd, 1 H), 8.20-8.25 (m, 2 H), 13.75-13.95 (br.s., 1 H). mass spectrum (-ESI), m/z 651/653 (M-H).

Provenance & Evidence