Patent / 1976
16-Methyl-9.alpha.-halogen steroid esters and ethers
Prednisolone mixed esters I (R = Cl, F; R1 = H, EtCO, F3CCO; R2 = H, AcO, EtCO2; R3 = H, BuCO, EtCO) (18 compds.) were prepd. Thus, acylation of I(R = Cl, F; R1 = H, R2 = H, AcO) with (F3CCO)2O gave I (R1 = F3CCO) which was acylated with (BuCO)2O. Solvolysis of I (R1 = F3CCO, tetrahydropyran-2-yl; R2 = H; R3 = BuCO) gave I (R1 = H, R2 = H, R3 = BuCO) which was acylated with (EtCO)2O to I (R1 = EtCO, R2 = H, R3 = BuCO). Treatment of I (R1 = F3CCO, R2 = H, R3 = BuCO) with iodine and CaO followed by KOAc gave I (R1 = F3CCO, R2 = AcO, R3 = BuCO) which underwent solvolysis and addnl. acylation. I (R = F, R1 = EtCO, R2 = H, R3 = BuCO) had 7 times the antiinflammatory activity as fluocinolone acetonide.