Synthesis and Structure-Activity Relationships in a Series of Antiinflammatory Corticosteroid Analogs, Halomethyl Androstane-17.beta.-carbothioates and -17.beta.-carboselenoates
作者:Gordon H. Phillipps、Esme J. Bailey、Brian M. Bain、Raymond A. Borella、Jacky B. Buckton、John C. Clark、Alice E. Doherty、Alan F. English、Harold Fazakerley
DOI:10.1021/jm00048a008
日期:1994.10
The preparation and topical antiinflammatory potencies of a series of halomethyl 17 alpha-(acyloxy)11 beta-hydroxy-3 -oxoandrosta-1,4-diene-17 beta-carbothioates, carrying combinations of 6 alpha-fluoro, 9 alpha-fluoro, 16-methyl, and 16-methylene substituents, are described. Key synthetic stages were the preparation of carbothioic acids and their reaction with dihalomethanes. The carbothioic acids were formed from 17 beta-carboxylic acids by initial reaction with dimethylthiocarbamoyl chloride followed by aminolysis of the resulting rearranged mixed anhydride with diethylamine, or by carboxyl activation with 1,1'-carbonyldiimidazole (CDI) or 2-fluoro-N-methylpyridinium tosylate (FMPT) and reaction with hydrogen sulfide, the choice of reagent being governed by the 17 alpha-substituent. Carboxyl activation with FMPT and reaction with sodium hydrogen selenide led to the halomethyl 16-methyleneandrostane-17 beta-carboselenoat analogues. Antiinflammatory potencies were measured in humans using the vasoconstriction assay and in rats and mice by a modification the Tonelli croton oil ear assay. Best activities were shown by fluoromethyl and chloromethyl carbothioates with a 17 alpha-propionyloxy group. S-Fluoromethyl 6(alpha,9 alpha-difluoro-11 beta-hydroxy-16 alpha-methyl-3-oxo-17 alpha-(propionyloxy)androsta-1,4-diene-17 beta-carbothioate (fluticasone propionate, FP) was selected for clinical study as it showed high topical antiinflammatory activity but caused little hypothalamic-pituitary-adrenal suppression after topical or oral administration to rodents.