反应详情

A mixture of 2-(4-hydroxybenzyl)-2-phenoxybutyric acid ethyl ester (0.030 mmol) (see Ex. 40, 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-(4-{2-[5-methyl-2-(3-thiophen-2-yl-phenyl)-oxazol-4-yl]-ethoxy}-benzyl)-2-phenoxy-butyric acid. 1H NMR (400 MHz, CDCl3) δ 8.22–8.21 (m, 1H), 7.89–7.85 (m, 1H), 7.66–7.62 (m, 1H), 7.45–7.40 (m, 2H), 7.32–7.25 (m, 3H), 7.11–6.97 (m, 6H), 6.77 (d, 2H, J=8.4 Hz), 4.20 (t, 2H, J=6.4 Hz), 3.29 (s, 2H), 2.98 (t, 2H, J=6.4 Hz), 2.39 (s, 3H), 2.14 (qd, 1H, J=14.6, 7.6 Hz), 2.07 (qd, 1H, J=14.6, 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