Patent ID: 6528666
Filing Date: 2003-03-04
Classification: A61P,C07J,Y02P

Abstract:
A process for preparing flumethasone, 6&agr;,9&agr;-difluoro-11&bgr;, 17&agr;,21-trihydroxy-16&agr;-methyl-pregna-1,4-diene-3,20-dione, flumethasone 21-acetate or its 17-carboxyl androsten analogue of the formula: characterized by the fact that a compound of the formula: is reacted with benzoyl chloride to form a 3-enolic ester of the formula: the enol benzoate (III a) thus obtained is reacted with an electrophilic fluorination agent so as to introduce fluorine the 6&agr;-position, the enol benzoate (III b) is deprotected at C3 to yield a compound of the formula: the 9,11-epoxy group of compound IV is fluorinated by reaction with hydrofluoric acid to yield flumethasone 21-acetate, and optionallythe flumethasone 21-acetate is hydrolyzed in the presence or absence of an oxidization agent to yield compound I or flumethasone, respectively.