Diethyl Ether → 2-{3-[3-(2-Ethyl-5-hydroxy-4-oxazol-4-yl-phenoxy)propoxy]-2-propyl-phenoxy}benzoic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-(3-{3-[5-benzyloxy-2-ethyl-4-(2-hydroxyacetyl)phenoxy]propoxy}-2-propylphenoxy)benzoic acid methyl ester (1.39 g, 2.27 mmol) in methylene chloride (20 mL) cooled to −78° C. was added triflic anhydride (0.57 mL, 3.4 mmol) and 2,6-lutidine (0.40 mL, 3.4 mmol). The resulting mixture was stirred for 1 h then poured into ether and water. The organic layer was separated and washed once with saturated sodium chloride solution, dried (sodium sulfate), filtered, and concentrated in vacuo. The residue was dissolved in a 2:1 mixture of formamide/N,N-dimethylformamide (9 mL) and heated at 120° C. in a sealed tube for 4 h. The mixture was cooled to room temperature and diluted with ethyl acetate. The mixture was washed four times with water, once with saturated sodium chloride solution, dried (sodium sulfate), filtered, and concentrated in vacuo. Chromatography (silica gel, 10% ethyl acetate/90% hexane) of the residue provided 89 mg (6%) of the title product as a colorless oil. 1H NMR (CDCl3) δ 7.92 (s, 1H), 7.85 (s, 1H), 7.83 (m, 2H), 7.35 (m, 6H), 7.03 (d, J=8 Hz, 1H), 7.00 (d, J=8 Hz, 1H), 6.73 (d, J=8 Hz, 1H), 6.62 (d, J=8 Hz, 1H), 6.52 (s, 1H), 6.35 (d, J=8 Hz, 1H), 5.07 (s, 2H), 4.14 (m, 4H), 3.76 (s, 3H), 2.61 (m, 4H), 2.26 (quintet, J=6 Hz, 2H), 1.48 (hextet, J=7 Hz, 2H), 1.15 (t, J=8 Hz, 3H), 0.84 (t, J=8 Hz, 3H).

Provenance & Evidence