反应详情

1-Chloroethylchloroformate (3.24 mL) was added dropwise to a solution of compound 1 (5.22 g) in dichloromethane (75 mL) at 0° C. The solution was then heated to reflux for 3 hours, cooled to room temperature and concentrated in vacuo. The residue was then dissolved in methanol (75 mL) and heated to reflux for another 3 hours. The mixture was cooled to 0° C. and ether (200 mL) was added. Filtration afforded the title compound 2 as a white solid (3.38 g, 90%). LCMS: Rf: 0.380 min, M+H+: 231.

1. temperatureThe solution was then heated
2. temperatureto reflux for 3 hours
3. concentrationconcentrated in vacuo
4. dissolutionThe residue was then dissolved in methanol (75 mL)
5. temperatureheated
6. temperatureto reflux for another 3 hours
7. temperatureThe mixture was cooled to 0° C.
8. additionether (200 mL) was added
9. filtrationFiltration