反应详情

To a suspension of sodium hydride (60% in oil, 1.71 g, 42.8 mmol) in THF (40 mL), 4-methoxybenzenethiol (5.0 g, 35.7 mmol) was added dropwise at room temperature over a period of 10 min. The mixture was stirred at room temperature under N2 for 10 min and then cooled to 0° C. Ethyl bromoacetate (4.0 mL, 36 mmol) was added dropwise at 0° C. over a period of 10 min. The reaction mixture was stirred at room temperature for 30 min and then quenched with saturated ammonium chloride. The organic layer was separated and the aqueous layer was extracted with ethyl acetate (2×). The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated in vacuo. The residue was purified by chromatography on silica gel (1:9 ethyl acetate/hexanes) to provide (4-methoxy-phenylsulfanyl)-acetic acid ethyl ester (7.9 g, 98%) as colorless oil: 1H NMR (300 MHz, CDCl3) δ 7.42 (d, J=6.6 Hz, 2H), 6.84 (d, J=6.6 Hz, 2H), 4.11 (q, J=7.1 Hz, 2H), 3.80 (s, 3H), 3.51 (s, 2H), 1.21 (t, J=7.1 Hz, 3H); ESI MS m/z 227 [(M+H)+, calcd for C11H15O3S, 227.0].

1. additionwas added dropwise at room temperature over a period of 10 min
2. temperaturecooled to 0° C
3. stirringThe reaction mixture was stirred at room temperature for 30 min
4. customquenched with saturated ammonium chloride
5. customThe organic layer was separated
6. extractionthe aqueous layer was extracted with ethyl acetate (2×)
7. washThe combined organic layers were washed with brine
8. dry with materialdried over Na2SO4
9. filtrationfiltered
10. concentrationconcentrated in vacuo
11. customThe residue was purified by chromatography on silica gel (1:9 ethyl acetate/hexanes)