反应详情

A mixture of 2-(4-hydroxybenzyl)-2-phenoxybutyric acid ethyl ester (0.030 mmol), toluene-4-sulfonic acid 2-(5-methyl-2-biphenyl-4-yl-oxazol-4-yl)ethyl ester (0.030 mmol) (see Ex. 1, Part I) 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-{4-[2-(2-Biphenyl-4-yl-5-methyl-oxazol-4-yl)-ethoxy]-benzyl}-2-phenoxy-butyric acid. 1H NMR (400 MHz, CDCl3) δ 8.05–8.03 (m, 2H), 7.68–7.61 (m, 4H), 7.48–7.44 (m, 2H), 7.40–7.35 (m, 1H), 7.32–7.25 (m, 2H), 7.09–6.96 (m, 5H), 6.79–6.70 (m, 2H), 4.19 (t, 2H, J=6.4 Hz), 3.29 (s, 2H), 2.99 (t, 2H, J=6.4 Hz), 2.39 (s, 3H), 2.14 (qd, 1H, J=14.8, 7.6 Hz), 2.07 (qd, 1H, J=14.8, 7.6 Hz), 0.91 (t, 3H, J=7.6 Hz).

1. temperaturewas heated
2. temperatureto reflux for 24 h under N2
3. temperaturewas heated
4. temperatureat reflux for an additional 2 h
5. temperatureThe reaction was cooled
6. customthe solvent removed in vacuo
7. extractionextracted with water and CH2Cl2
8. customthe organic layer dried
9. customThe solvent was removed in vacuo