title: A novel class of potent topical antiinflammatory agents: 17-benzoylated, 7 alpha-halogeno substituted corticosteroids.
abstract: As part of continued efforts in the synthesis of structurally novel corticosteroids, a number of 17 alpha-benzoylated, 7 alpha-halogeno substituted prednisolones were tested for topical antiinflammatory activity. 7 alpha-Chloro, 7 alpha-bromo, and 7 alpha-iodo corticosteroids were synthesized by hydrogen halide addition to 1,4,6-triene-3-ones. The 7 alpha-fluoro substituted steroid was obtained by reaction of the appropriate 7 beta-hydroxy compound with N,N-diethyl(2-chloro-1,1,2-trifluoroethyl)amine. Antiinflammatory potencies were obtained using a croton oil-induced inflammation in the ears of mice. In this assay the greatest effect of a 7 alpha-halogen was observed in the 16 alpha-methylprednisolone series, where 7 alpha-fluoro and 7 alpha-bromo substitution yielded corticosteroids with topical potencies significantly higher than those of the corresponding 17,21-dipropionate analogs. Surprisingly, little potency enhancement due to 7 alpha-halogenation was discerned in the 16 beta-methylprednisolone series.
mesh_terms: D000287:Administration, Topical; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000138:chemical synthesis*; D055598:Chemical Phenomena; D002621:Chemistry; D005938:Glucocorticoids; D051379:Mice; D013329:Structure-Activity Relationship
chemical_list: D000893:Anti-Inflammatory Agents; D005938:Glucocorticoids