反应详情

温度

75 °C

To a solution of 3-methoxy-thiophenol (1.4 g, 0.01 mol) and 2-phenylbutyrolactone 2a (1.5 g, 0.0093 mol, (Tetrahedron 47, (8) 1525-40, 1991) in DMF (10.0 mL) were added potassium carbonate (1.4 g, 0.01 mol) and 18-crown-C (0.05 g), and the mixture was heated at 75° C. for 12 h under an atmosphere of argon. The reaction mixture was cooled, and partioned between 5% citric acid (25 mL) and ethylacetate (50 mL). The organic phase was washed with water (2×25 mL), dried dried (Na2SO4) and concentrated under reduced pressure to give a yellow syrup. This was purified by silica gel flash chromatography using 20% EtOAc in hexane. Fractions containing the desired acid as monitored by ES mass spectrometry, [m/z=303 (M+H)] were combined and concentrated. This material was dissolved in EtOH (5 mL), added 4N HCl/dioxane (5.0 mL) and stirred at room temperature for 1 h, and at 70° C. for 1 h. The resulting solution was concentrated to dryness and the residue was purified by silica gel flash chromatography using 20% EtOAc in hexane to give 1.2 g (40%) of the desired ester as a pale yellow liquid: 1H-NMR (400 Mz, CDCl3) δ 7.35-7.15 (m, 5H), 6.87 (m, m 1H), 6.85 (m, 1H), 6.70(m, 1H), 4.02 (m, 2H), 3.77 (m, 3H), 3.18 (d, 2H, J=7.2 Hz), 2.92 (dd, 1H, J=6.4 Hz), 2.65 (dd, 1H, J=8.0 Hz), and 1.11 (t, 3H, J=6.8 Hz); ES-MS m/z 331 (M+H)+; HR-MS Calcd C19H23O3S 331.1100, found 331.1377.

1. temperatureThe reaction mixture was cooled
2. washThe organic phase was washed with water (2×25 mL)
3. customdried
4. dry with materialdried (Na2SO4)
5. concentrationconcentrated under reduced pressure
6. customto give a yellow syrup
7. customThis was purified by silica gel flash chromatography
8. additionFractions containing the desired acid
9. concentrationconcentrated
10. dissolutionThis material was dissolved in EtOH (5 mL)
11. additionadded 4N HCl/dioxane (5.0 mL)
12. waitat 70° C. for 1 h
13. concentrationThe resulting solution was concentrated to dryness
14. customthe residue was purified by silica gel flash chromatography