Potassium Carbonate → 2-(Benzo[1,3]dioxol-5-yloxy)-2-methyl-3-(4-{2-[5-methyl-2-(3-thiophen-2-yl-phenyl)-oxazol-4-yl]-ethoxy)-phenyl)-propionic acid

Participants

Reaction Steps

A mixture of 2-(benzo[1,3]dioxol-5-yloxy)-3-(4-hydroxyphenyl)-2-methyl-propionic acid ethyl ester (0.030 mmol) (see Ex. 58, Part C), toluene-4-sulfonic acid 2-[5-methyl-2-(3-thiophen-2-ylphenyl)oxazol-4-yl]ethyl ester (0.030 mmol) (see Ex. 5, Part B) and 325 mesh K2CO3 (0.084 g, 0.60 mmol) in ethanol (2 mL) was heated to reflux for 24 h under N2. Aqueous 5N NaOH (0.5 mL) and additional ethanol (1 mL) was added to the reaction mixture and it was heated at reflux for an additional 2 h. The reaction was cooled and the solvent removed in vacuo. The residue was acidified with aqueous 1 N HCl (5 mL), extracted with water and CH2Cl2 and the organic layer dried by passing it through a Varian Chem Elut 1003 cartridge. The solvent was removed in vacuo to give 2-(benzo[1,3]dioxol-5-yloxy)-2-methyl-3-(4-{2-[5-methyl-2-(3-thiophen-2-yl-phenyl)-oxazol-4-yl]-ethoxy}-phenyl)-propionic acid. 1H NMR (400 MHz, CDCl3) δ 8.19 (t, 1H, J=1.71 Hz), 7.85–7.82 (m, 1H), 7.67–7.63 (m, 1H), 7.42 (t, 1H, J=7.82 Hz), 7.38–7.37 (m, 1H), 7.28–7.26 (m, 1H), 7.13 (d, 2H, J=8.79 Hz), 7.06 (dd, 1H, J=4.88 Hz, J=3.42 Hz), 6.79 (d, 2H, J=8.79 Hz), 6.60 (d, 1H, J=8.30 Hz), 6.40 (d, 1H, J=2.44 Hz), 6.32 (dd, 1H, J=8.30 Hz, J=2.44 Hz), 5.87 (d, 2H, J=0.98 Hz), 4.19 (t, 2H, J=6.11 Hz), 3.15 (d, 1H, J=14.17 Hz), 3.04–3.01 (m, 3H), 2.39 (s, 3H), 1.30 (s, 3H);HRMS (ES+) m/z exact mass calcd for C33H30NO7S 584.1743, found 584.1744.

Provenance & Evidence