反应详情

To a solution of 282b (33.0 g, crude) in dichloromethane (400 mL) and triethylamine (60 g, 600 mmol) was added ethyl 2-mercaptoacetate (19.2 g, 160 mmol). The reaction mixture was heated at reflux for 6 h. It was then concentrated under reduced pressure. The residue was dissolved in ethanol (400 mL) and triethylamine (60 g, 600 mmol). The mixture was heated at reflux for 12 h. It was concentrated again under reduced pressure and the residue was purified by silica-gel column chromatography eluting with 40:1 petroleum ether/ethyl acetate to afford 282c as yellow solid (18.0 g, 32%, over two steps). MS-ESI: [M+H]+ 225.3. 1H NMR (500 MHz, DMSO-d6) δ 7.49 (s, 1H), 4.32 (q, J=7.0 Hz, 2H), 2.72 (s, 2H), 2.56 (s, 2H), 1.35 (t, J=7.0 Hz, 3H), 1.22 (s, 6H).

1. temperatureThe reaction mixture was heated
2. temperatureat reflux for 6 h
3. concentrationIt was then concentrated under reduced pressure
4. dissolutionThe residue was dissolved in ethanol (400 mL)
5. temperatureThe mixture was heated
6. temperatureat reflux for 12 h
7. concentrationIt was concentrated again under reduced pressure
8. customthe residue was purified by silica-gel column chromatography
9. washeluting with 40:1 petroleum ether/ethyl acetate