抄録
17α-Acyloxy-11β, 21-dihydroxy-2'-phenyl-2'H-2, 4-pregandieno[3, 2-c]pyrazol-20-one derivatives (3a, 3b, 4, 5a and 5c) were synthesized and tested for vasoconstrictive activities. Compound 3b showed the most potent activity, which was greater than that of 9α-fluoro-11β, 21-dihydroxy-16β-methyl-17α-valeroyloxy-1, 4-pregnadiene-3, 20-dione (betamethasone 17-valerate, BV). The activities of all other compounds (3a, 4, 5b and 5c) were rather weaker than that of the mother compound, 11β, 17α, 21-trihydroxy-2'-phenyl-2'H-2, .4-pregnadieno[3, 2-c]pyrazol-20-one (1). In contrast to the case of corticosteroids having a hydrocortisone-type skeleton, esterification of both the 17- and 21-hydroxy groups of the pyrazole-fused compound (1) or the substitution of the 21-hydroxy group of the 17-ester compound (3) with a chlorine atom are not always necessary for the exhibition of higher activity.
