反应详情

Acetic anhydride (3.2 g, 31.31 mmol) is heated to 115° C. under an argon atmosphere. The compound of Example 30A (700 mg, 5.22 mmol) is added and the solution is stirred at reflux for one hour. Ethanol (3 ml, 51.12 mmol) is added dropwise to the mixture and refluxing is continued for 10 minutes. The mixture is cooled to room temperature, poured into ice water and neutralised with saturated sodium bicarbonate solution. The aqueous phase is extracted with diethyl ether. The organic phase is washed with brine, dried with magnesium sulphate, filtered and concentrated in vacuo to afford a black oil. The oil is dissolved in dimethylsulfoxide (8 ml) and purified by preparative HPLC.

1. temperatureat reflux for one hour
2. temperaturerefluxing
3. extractionThe aqueous phase is extracted with diethyl ether
4. washThe organic phase is washed with brine
5. dry with materialdried with magnesium sulphate
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customto afford a black oil
9. custompurified by preparative HPLC