反应详情

15.1 g (71.9 mmol) of the compound from Example 3A and 10.0 g (71.9 mmol) of the compound from Example 4A are dissolved in 375 ml ethanol and 1.7 g (7.2 mmol) camphor-10-sulfonic acid are added. The mixture is heated under reflux for 16 h. After cooling to RT, the reaction mixture is concentrated and the residue is purified by column chromatography over silica gel (mobile phase: methylene chloride/methanol 9:1, then 1:1). The product fraction is concentrated in vacuo and the residue is stirred in diisopropyl ether, filtered off and dried in vacuo.

1. temperatureThe mixture is heated
2. temperatureunder reflux for 16 h
3. concentrationthe reaction mixture is concentrated
4. customthe residue is purified by column chromatography over silica gel (mobile phase
5. concentrationThe product fraction is concentrated in vacuo
6. filtrationfiltered off
7. customdried in vacuo