METHOD FOR PREPARING FLUMETASONE, COMPOUND Russian patent published in 2005 - IPC

FIELD: organic chemistry, chemical technology, pharmacy.

SUBSTANCE: invention describes the improved method for preparing flumetasone (6α,9α-difluoro-11β,17α,21-trihydroxy-16α-methylpregna-1,4-diene-3,20-dione), flumetazone 21-acetate or its 17-carboxyl-androstene analogue of the formula (I) . Method involves interaction of benzoyl chloride with compound of the formula (II) in pyridine medium of its mixture with N,N'-dimethylacetamide to prepare 3-enol ester of the formula (IIIa) and it's the following interaction with 1-(chloromethyl)-4-fluoro-1,4-diazonium-bicyclo[2.2.2]octane-bis(tetrafluoroborate) in acetonitrile medium and water to prepare compound of the formula (IIIb) and the following removing the protective group in compound of the formula (IIIb) at the position C3 in medium of aqueous metabisulfite and ammonia to prepare compound of the formula (IV) . After the fluorination reaction of 9,11-epoxy group in compound of the formula (IV) using HF flumetasone 21-acetate is prepared followed by the selective hydrolysis with KOH in methanol (CH₃OH) medium in the presence or absence of H₂O₂ to prepare compound of the formula (I) or flumetasone, respectively.

EFFECT: improved preparing method.

3 cl, 5 ex