Cesium carbonate → 2-Methyl-3-(4-{2-[5-methyl-2-(3-thiophen-3-ylphenyl)oxazol-4-yl]ethoxy}phenyl)-2-phenoxypropionic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

3-(4-Hydroxyphenyl)-2-methyl-2-phenoxypropionic acid ethyl ester (495 mg, 1.7 mmol) (see Ex. 1, Part C), toluene-4-sulfonic acid 2-[5-methyl-2-(3-thiophen-3-ylphenyl)oxazol-4-yl]ethyl ester (2.2 mmol) and Cs2CO3 (700 mg, 2.2 mmol) are combined in anhydrous DMF (25 mL) and stirred for 16 h at 55° C. under an atmosphere of nitrogen. The mixture was then cooled and diluted with ethyl acetate (100 mL), and washed with water then brine. The organic layer was dried with Na2SO4 and concentrated in vacuo to a viscous yellow oil. The residue was purified by flash column chromatography (100 g silica, 60×15 mL fractions, gradient elution 0–20% ethyl acetate in hexanes) to provide the title compound as a colorless oil. 1H NMR (400 MHz, CDCl3) δ 8.23 (s, 1H), 7.90 (dt, J=7.6 Hz, J=1.2 Hz, 1H), 7.64 (dt, J=7.6 Hz, J=1.2 Hz, 1H), 7.56–7.55 (m, 1H), 7.48–7.39 (m, 3H), 7.23–7.14 (m, 5H), 6.96 (t, J=7.2 Hz, 1H), 6.83–6.81 (m, 4H), 4.24 (t, J=6.8 Hz, 2H), 4.12 (q, J=7.2 Hz, 2H), 3.26 (d, J=14.0 Hz, 1H), 3.10 (d, J=14.0 Hz, 1H), 3.00 (t, J=6.4 Hz, 2H), 2.39 (s, 3H), 1.38 (s, 3H) 1.21 (t, J=7.2 Hz, 3H); MS (EI) 568.2 (M+H)+.

Provenance & Evidence