反应详情

A mixture of 3.5 g of 11β-trimethylsiloxy-21-acetoxy-6α-fluoropregna-4,16-diene-3,20-dione obtained according to Example 6, 2.65 g of 2,3-dichloro-4,5-dicyanobenzoquinone (DDQ) and 30 ml of dioxan was heated under reflux for 2 hours. The resulting dark colored suspension was cooled, filtered from dichloro-dicyanohydroquinone, and evaporated to dryness. The residue was dissolved in chloroform and passed through a short column of neutral alumina (50 g). The solvent was evaporated under reduced pressure. The residue was crystallized from methanol. The analytical sample of 11β-trimethylsiloxy-21-acetoxy-6α-fluoropregna-1,4,16-triene-3,20-dione (compound 13) was obtained by an additional recrystallization from methanol. The yield was 2.65 g.

1. customobtained
2. temperaturewas heated
3. temperatureunder reflux for 2 hours
4. temperatureThe resulting dark colored suspension was cooled
5. filtrationfiltered from dichloro-dicyanohydroquinone
6. customevaporated to dryness
7. dissolutionThe residue was dissolved in chloroform
8. customThe solvent was evaporated under reduced pressure
9. customThe residue was crystallized from methanol