反应详情

A mixture of 2-(m-tolyloxy)-3-(4-hydroxyphenyl)-2-methyl-propionic acid ethyl ester (0.095 g, 0.030 mmol) (see Ex. 48, Part C), toluene-4-sulfonic acid 2-(5-methyl-2-biphenyl-4-yl-oxazol-4-yl)ethyl ester (0.030 mmol) 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 3-{4-[2-(2-biphenyl-4-yl-5-methyl-oxazol-4-yl)-ethoxy]-phenyl}-2-methyl-2-m-tolyloxy-propionic acid. 1H NMR (400 MHz, CDCl3) δ 8.06 (d, 2H, J=8.21 Hz), 7.70 (d, 2H, J=8.60 Hz), 7.64–7.62 (m, 2H), 7.48–7.45 (m, 2H), 7.41–7.37 (m, 1H), 7.18 (d, 2H, J=8.60 Hz), 7.12 (t, 1H, J=7.82 Hz), 6.86–6.81 (m, 3H), 6.72–6.68 (m, 2H), 4.22 (t, 2H, J=5.86 Hz), 3.24 (d, 1H, J=14.08 Hz), 3.13 (d, 1H, J=14.08 Hz), 3.08 (t, 2H, J=5.86 Hz) 2.44 (s, 3H), 2.28 (s, 3H), 1.42 (s, 3H); HRMS (ES+) m/z exact mass calcd for C35H34NO5 548.2437, found 548.2459.

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