Acetic Anhydride → 2-Acetoxy-4-{4-[2-(4-Bromo-benzyl)-4,5-dimethyl-thiophene-3-carbonyl]-2-cyclopentyl-phenoxysulfonyl}-benzoic Acid

Participants

Reaction Steps

The title compound was prepared according to the procedure in Example 22 using 4-{4-[2-(4-bromo-benzyl)-4,5-dimethyl-thiophene-3-carbonyl]-2-cyclopentyl-phenoxysulfonyl}-2-hydroxy-benzoic acid (0.211 g, 0.315 mmol), magnesium iodide (0.0876 g, 0.315 mmol) and acetic anhydride (2.5 mL) in ether. Purification on 2% H3PO4 /MeOH treated silica gel, eluting with a 10 & 20% EtOAc/pet ether step gradient followed by crystallization from acetone/hexane gave 0.185 g (57%) of the title compound as a white solid, mp 113-114° C. 1H NMR (DMSO-d6) δ 1.27-1.34 (m, 2 H), 1.51-1.58 (m, 2 H), 1.63-1.78 (m, 4 H), 1.80 (s, 3 H), 2.25 (s, 3 H), 2.28 (s,3 H), 2.95 (quintet, 1 H), 3.86 (s, 2 H), 6.97 (d, 2 H), 7.24 (d, 1 H), 7.38 (d, 2 H) 7.52 (dd, 1 H), 7.57 (d, 1 H), 7.86 (d, 1 H), 7.92 (dd, 1 H), 8.16 (d, 1 H) 13.8 (br s, 1 H). mass spectrum (-ESI) m/z 709 (M-H). Anal. Calcd. for C34H31BrO8S2 : C, 57.38; H, 4.39; N, 0.00. Found: C, 56.99; H, 4.38; N, 0.02.

Provenance & Evidence