Atorvastatin Intermediate
Clobetasol (Clobetasol Propionate EP Impurity G) is a topical corticosteroid. Glucocorticoid; anti-inflammatory.
ChEBI: A 3-oxo-Delta1,Delta4-steroid that is 16beta-methylpregna-1,4-diene-3,20-dione bearing hydroxy groups at the 11beta and 17alpha posit
ons, fluorine at position 9, and a chlorine substituent at position 21. It is used as its 17alpha-propionate ester to treat various skin disorders, including exzema and psoriasis.
A solution of betamethasone 21-methanesulfonate (4 g) in dimethylformamide
(25 ml) was treated with lithium chloride (4 g) and the mixture heated on the
steam bath for 30 minutes. Dilution with water gave the crude product which
was recrystallized to afford the title compound, MP 226°C.
Clobetasol is usually converted to the propionate as the useful form by
reaction with propionic anhydride.
Clobex (Galderma); Clobex (Galderma);
Embeline (Healthpoint); Olux (Connetics); Temovate
(Altana).
Corticosteroid, Antiinflammatory
