9-fluoro-11beta,17,21-trihydroxy-16beta-methylpregna-1,4-diene-3,20-dione 17,21-di(valerate)

Originator

Valisone,Schering,US,1967

Manufacturing Process

The valerate is made from betamethasone as a starting material as follows: A suspension of 9α-fluoro-11β,17α,21-trihydroxy-16β-methylpregna-1,4-diene- 3,20-dione(betamethasone) (2 grams) in sodium dried benzene (500 ml) was distilled vigorously for a few minutes, toluene-p-sulfonic acid monohydrate (30 mg) and methyl orthovalerate (5 ml) were added and distillation was continued for 10 minutes. The mixture was then boiled under reflux for 1.5 hours after which time unreacted betamethasone alcohol (400 mg) was removed by filtration. The benzene solution was treated with solid sodium .bicarbonate and a few drops of pyridine, filtered and evaporated to dryness at about 50°C. The residue, in ether, was filtered through grade III basic alumina (20grams) to remove traces of unreacted betamethasone alcohol, the ether removed in vacuo and the residue of crude betamethasone 17,21- methyl orthovalerate was treated with acetic acid (20ml) and a few drops of water and left overnight at room temperature.
The acetic acid solution was poured into water (100 ml) and extracted with chloroform. The chloroform extracts were washed in turn with water, saturated sodium bicarbonate solution and water, dried and evaporated in vacuo. The residual gum was triturated with ether and a white crystalline solid (1.16 grams) isolated by filtration. Recrystallization from ether (containing a small amount of acetone)-petroleum ether gave 9α-fluoro-11β,21-dihydroxy-16β- methyl-17α-valeryloxypregna-1,4-diene-3,20-dione (871 mg) as fine needles.

Therapeutic Function

Corticosteroid