Preparation of pharmacologically active 16-methyl-9.alpha.-halo steroid esters and ethers
Halopregnadienediones I [R = Cl, F; R1 = OH, O2CEt, (tetrahydropyran-2-yl)oxy; R2 = H, OH, O2CEt, O2CBu; R3 = OH, OAc, O2CEt] (15 compds.) were prepd. by selective acylation and solvolysis. Thus, I (R = Cl, R1 = O2CCF3, R2 = H, R3 = O2CBu) (II) was hydrolyzed using NaHCO3-H2O to give I (R = Cl, R1 = OH, R2 = H, R3 = O2CBu) which was acylated with EtCO2H in the presence of (F3CCO)2O to give I (R = Cl, R1 = O2CEt, R2 = H, R3 = O2CBu). Iodination of II followed by acetoxylation gave I (R = Cl, R1 = O2CCF3, R2 = OAc, R3 = O2CBu). Acylation of I (R = Cl, R1 = R3 = OH, R2 = H) by (F3CCO)2O gave I (R = Cl, R1 = O2CCF3, R2 = H, R3 = OH) which after treatment with BuCO2H-(F3CCO)2O gave II. I (R = F, R1 = O2CEt, R2 = H, R3 = O2CBu) had 7 times the topical antiinflammatory activity of fluocinolone acetonide in the McKenzie vasoconstrictor topical test.