9.alpha.-Fluoro or 9.alpha.-chloro corticosteroid esters
Title esters I (R = Cl, OR1; R1, R2 = C2-6 acyl, benzoyl; R3 = .alpha.- or .beta.-Me or -F; X = Cl, F; .DELTA.1 may be present or absent) were prepd. by reacting the epoxides II with HCl or HF. Thus, II (R = O2CPh, R2 = COEt, R3 = .alpha.-Me, .DELTA.1 present) was added slowly to 50% HCl in DMF at -5.degree. to 0.degree., followed by stirring for 2.5 h and pptn. in aq. NH3 and ice to give 96% I (X = Cl, others as above). Twenty-seven other I were similarly prepd., many (esp. with X = Cl) being novel antiinflammatories, and most of these having activities comparable to or greater than betamethasone 17-valerate in the rat-paw edema test. I (R = O2CPr, R2 = COPr, COEt, R3 = .alpha.-Me, X = Cl, .DELTA.1 present) were particularly active.