Reaction #502084

Reaction equation

Betulin

Jones Reagent

→

betulonic acid

Solvents

benzene

methanol

acetone

Conditions

Workup

1. 1
   workup.ADDITIONadded dropwise at 0° C
2. 2
   Otherquench with methanol (100 mL)
3. 3
   workup.STIRRINGstir for 5 minutes
4. 4
   workup.ADDITIONadd H2O (200 mL)
5. 5
   OtherRemove organic solvent under vacuum, and then separate the precipitate
6. 6
   Filtrationby filtration
7. 7
   WashWash precipitate on the
8. 8
   Filtrationfilter with cooled water
9. 9
   Otherdry
10. 10
    Otherto obtain crude material
11. 11
    FiltrationThe solution is then filtered through a layer of aluminum oxide
12. 12
    workup.ADDITIONthe eluate is treated with an aqueous 10% KOH solution until complete precipitation
13. 13
    OtherThe precipitate is then separated by filtration
14. 14
    Washwashed with 10 mL
15. 15
    Temperaturecooled benzene
16. 16
    Otherdried
17. 17
    Otherto obtain white solid
18. 18
    workup.ADDITIONthe solution is poured into 100 mL 15% aqueous HCL solution

Procedure

Starting off with Betulin (10 g) in acetone (300 mL), add freshly prepared Jones Reagent added dropwise at 0° C. Stir for 5 hours, quench with methanol (100 mL), then stir for 5 minutes and add H2O (200 mL). Remove organic solvent under vacuum, and then separate the precipitate by filtration. Wash precipitate on the filter with cooled water, and dry to obtain crude material. This dry material is to be dissolved in 30 mL benzene. The solution is then filtered through a layer of aluminum oxide and the eluate is treated with an aqueous 10% KOH solution until complete precipitation. The precipitate is then separated by filtration, washed with 10 mL cooled benzene, and dried to obtain white solid. The salt is dissolved in 30 mL methanol and the solution is poured into 100 mL 15% aqueous HCL solution. The betulonic acid (2.7 g) is obtained after the precipitate is filtered, washed with water, and dried.

Source