Water → Hexaethyldisiloxane

Temperatur

0 °C

Cyclosporin A (3.606 g, 3 mmol) was dissolved in dry pyridine (8 mL) and then DMAP (122 mg, 1 mmol) was added. The reaction mixture was cooled to 0° C. and then triethylsilyl trifluoromethanesulfonate (3.6 mmol) added dropwise. The mixture was allowed to warm to room temperature and stirred overnight. The reaction mixture was then poured slowly into water with stirring. The precipitated triethylsilyl ether was filtered off and washed with water. The collected cake was dissolved in a minimum volume of methanol and added to a 5% citric acid solution and stirred for 30 minutes. The precipitated product was collected by filtration and washed with water until the pH of the filtrate reached that of the water. The solid triethylsilyl ether was dried at 50° C. under vacuum to give a colorless solid. Triisopropylsilyl and tert-butyldimethylsilyl protecting groups were also introduced by following an analogous procedure.

1. temperatureto warm to room temperature
2. stirringwith stirring
3. filtrationThe precipitated triethylsilyl ether was filtered off
4. washwashed with water
5. dissolutionThe collected cake was dissolved in a minimum volume of methanol
6. additionadded to a 5% citric acid solution
7. stirringstirred for 30 minutes
8. filtrationThe precipitated product was collected by filtration
9. washwashed with water until the pH of the filtrate
10. dry with materialThe solid triethylsilyl ether was dried at 50° C. under vacuum
11. customto give a colorless solid
12. additionTriisopropylsilyl and tert-butyldimethylsilyl protecting groups were also introduced

ORD-Eintrag

ord-0e5eb25b6d804d4ba1b90f7cfaaa05f8

Quelldatensatz

uspto-grants-2006_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06998385B2