,_ ‘2,989,526 United States Patent 0 ' CC Patented June 20, 1961

i 1 . ' 2 gen, methyl, or ?uoro; R3 and. R4 are hydrogen or methyl; 2,989,526 , and Ac is a lower 'alkano'ic acid residue of from 2 to 7 PROCESS FOR PREPARING carbon atoms inclusive. STEROIDAL IJACT ONES " The bonds represented by the symbol “5 ” are intended James F. Kerwin, Broomall, .and .Manfred E. ~Wol?, iElkins Park, Pa., ‘assignors .to Smith Kline & French’ to represent both the a and p con?guration of the group Laboratories, Philadelphia, Pa., a corporation of Penn so bound. , - . sylvania . . We have found that by treating the 11,18-epoxy-pregn No Drawing. Filed Apr. 21, 1960, Ser. No. 23,631 anes described above with ozone, there is affected a selec 9 Claims. (Cl. 260-23957) tive oxidation of the methylene group in the Iii-position 10 so as to yield the corresponding ll-hydroxy -18 This invention relates to a novel process for the'prep oic acid 11,18-lactones of Formula II. Furthermore, the aration of steroidal lactones. More speci?cally, it per ‘site of the reaction is speci?c to the 0-18 methylene func tains to the conversion of 11,18-oxido compounds tion. By employing ozone as the oxidizing agent rather to the corresponding 11,18-lactones (having the same than the materials utilized heretofore, higher yields are fundamental steroid nucleus) by the action of ozone. 15 obtained ‘with a concurrent greater ease of separation of In general this novel process is applicable to any com the ?nal product from the reaction medium. Further; pound possessing the fundamental cyclopentanohydro more, the use of ozone as the oxidizing agent oifers the phenanthrene nucleus, as for example, a pregnane, allo additional advantages of greater ease of preparation, con pregnane, 19-norpregnane or l9-norallopregnane, etio siderably lower initial cost, greater handling ease for or and which in addition, possesses 20 large scale preparations, and a lower toxicity factor for an epoxide linkage between the carbon atom designated as the operator. 0-11 and the carbon atom designated as C-l8. The The ‘reaction is advantageously executed by passing starting materials thus have as a minimal structure a 5 ozone gas through a solution of the starting material. membered epoxide ring, 4 of said S-ring members being The solvent employed may be any inert low molecular carbon atoms, which has a free methylene adjacent to the 25 weight organic solvent. Such suitable solvents include, oxygen ring member. Various other nonreactive substitu for example, saturated liquid hydrocarbons such ‘as pen ents such as halogen, lower alkyl, keto, lower alkanoyl tane, hexane, heptane and the like; halogenated hydro oxy, and the like may be optionally present in various carbons as for example chloroform, carbontetrachloride, positions of the steroid nucleus. Certain reactive centers s-tetrachloroethane, ethylene dichloride, as well as liquid such as unsaturated carbon bonds or hydroxyl groups 30 ?uorinated hydrocarbons and the like; lower alkyl must be protected during the reaction by known and ap alkanoic acid esters as for example ethyl acetate and propriate means, as for example halogenation of a double ethyl propionate; and lower alkyl ketones such as acetone, bond or esteri?cation of a free hydroxyl group thereby methylethyl ketone, diethylketone and the like. Certain converting reactive groups into groups unreactive under 35 more reactive solvents such as lower alkyl alcohols or un the condition of this process. Such protective groupings saturated hydrocarbons are not suitable due to'their re may then be removed subsequent to the key oxidation activity with ozone. ' process by the suitable means well-known to the art. The reaction is preferably carried out at temperatures The novel process of this invention can be illustrated, for example, as follows: from about 0 to about 40° C., however, temperatures as 40 low as —70° C. or as high as the boiling point of the o_-oH, solvent may be employed. v'Ihe reaction time is governed OHzOAo ’ O CHaOAc largely by the reactivity of the particular starting steroid;v CHOAc 0 (JJl JJHOAc however, the completion of te reaction can be readily de-' termined by measuring the intensity of the infrared ab MNRa 45 sorption attributed to y-lactones (about 5.65,u) at various R i R, I intervals during the introduction of the oxidizing agent. Upon completion of the reaction, hydrogen peroxide inl ~ —’03 1 which is formed during the course of the reaction is re

O- i 0_ moved by washing with water. The desired lactone is §\/ \/g\/ 50 then readily separated by removal of the solvent. H E H g The required 11,18-oxide starting materials are pre-* R: ’ R2 pared according to procedures described in copending ap (I) (II) plications. Such Serial No. 842,615, ?led September 28, Figure I 55 1959, now Patent No. 2,959,586. For the sake of clarity the general route may be summarized as follows:

re 69 CH3 N(CHa):

H0 OH=CH1 . .

~ 6 R4 , ~wRs X (1) Quaternization /; : (1) Alkali treatment. (2) Ion exchange resin R1 (2) Chromiq acid (3) Pyrolysis _ RM“, 2 oxidation (4) Quaternizatron H E R: 2,989,526 , 3 4 O——-—CH1 O-—-OH1 0_____cHl CHzOH CHzOAC CH=CH1 HOH CHOAc

MR1 MR2 MR: R4 I osmium /t Acylation _--) I‘; -—-——> tetroxide 1 0 —- E 0 H i R: (VI) Figure II wherein .Ac, R1, R2, R3, and R4 are as de?ned above; R5 20 Example 4 represents hydroxy, acetoxy, or taken together with the A solution of 500 mg. of 6,8-?uoro-11,18-oxido-20,21 carbon to which it is attached represents keto; and X is dipropionyloxypregnan-3-one in carbontetrachloride is hydroxyl or a reactive halide such as iodide or bromide. treated with ozone in the manner of Example 1 and there We have found that the 11,18-lactones prepared by our is thus obtained 3-keto-6?-?uoro-1l?-hydroxy-20,2l-di novel process possess the valuable physiological action of 25 propionyloxypregnan-l8-oic acid 11,18-lactone. diuresis. Furthermore, while possessing this activity in In an analogous fashion by employing the 6a-?uoro their own right, they also serve as valuable intermediates isomer of the starting material of this example, there is in the preparation of other more potent diuretic agents, obtained 3-keto-6a-?uoro-11?-hydroxy-20,2l-dipropionyl as for example, 3,20-diketo 11,6,2l-dihydroxy-4-pregnene oxy-pregnan-l8-oic acid 11,18-lactone. 18-oic acid 11,18’lactone. These conversions are de— 30 scribed in our copending applications. Example 5 The following examples will serve to illustrate further By substituting 750 mg. of 6/3-methyl-1L18-oxido the methods applicable to this invention. These examples, 20,21-diacetoxypregnane-3-one for the starting material however, should not be construed as limiting the scope of Example 1 and following the procedure therein de of this invention, the scope being de?ned only by the 35 scribed there is obtained 3-keto-6?-methyl-l1?-hydroxy~ appended claims. 20,21-diacetoxypregnan-18-oic acid 11,18-lactone. Example 1 Example 6 One gram of 11,18-oxido-20,21-diacetoxyallopregnan-3 11,18-oxido-16a-methyl-20,21-diacetoxypregnan-3 - one one is dissolved in 50 ml. of carbontetrachloride. A 40 (900 mg.) is treated with ozone in the manner of Ex stream of oxygen gas containing ozone gas is then bubbled ample l and there is thus obtained upon isolation as there through the solution while the temperature is maintained in described, 3-keto-1l?-hydroxy-l6a-methyl- 20,21-di at approximately 25° C. The degree of completion of acetoxypregnan-l8-oic acid 11,18-lactone. the reaction is determined at regular intervals by measur ing the infrared absorption of samples of the reaction Example 7 mixture at a wave length of 5.65M. When a constant 45 By employing 1 mg. of 11,l8-OXidO-9nc-?L1OI'O-20,Zl infrared absorption is found on successive measurements diacetoxyallopregnan-3-one as the starting material and the introduction of ozone is stopped and the reaction mix following the procedure of Example 1, there is obtained ture washed well with water. The solvent is then re upon isolation of the product in the prescribed manner, moved under reduced pressure to yield 3-keto-11/3-hy 3-keto-9tx-?uoro-1 1B-hydroxy~20,2 1 -diacetoxyallopreguan droxy-20,2l-diacetoxy--I8-oic acid 11,18 5 O 18-oic acid 11,18-lactone. lactone, as a solid. Similarly 250 mg. of 11,1S-OXidO-6oc,9oc-di?uO1'O-20,2l Example 2 diacetoxyallopregnan-3-one is converted to 3-keto—6a,9a One gram of 11,18-oxido-20,2l-diacetoxypregnan-Swne di?uoro-l l?-hydroxy-ZO,ZI-dihydroxyallopregnan-l8 - oic is dissolved in 50 ml. of s-tetrachloroethane and the re 55 acid 11,18-lactone. What we claim is: sultant solution treated with ozone as described in Ex 1. The process of preparing steroidal lactones having ample 1. Upon isolation as therein described, there is obtained 3-keto-11B-hydroxy-20,21-diacetoxypregnan~18 the following fundamental structure: oic acid 11,18-1actone. 60 0 (EHQOA-C Example 3 O_Gll (IJHOAc A solution of 5 g. of 11,18-oxido-20=,21-diacetoxy-19— norallopreguan-3-one in 200 ml. of methylene chloride is treated with ozone according to the procedure of Example 1, the temperature being maintained at 0° C. The re 65 /g\/ sultant product is isolated as therein described to yield 3 keto - 11B - hydroxy - 20,21-diacetoxy-19-noral1opregnan a.‘ 18-oic acid 11,18-lactone. g\/ In a similar fashion, 11,18--oXido-20,21-diacetoxy-19 H 2 norpregnan-3-one is subjected to the oxidative procedure 70 R2 herein described. The reaction is carried out at the re wherein R1 is a member selected from the group consist ?ux temperature of the methylene chloride (ca. 40° C.) ing of hydrogen and fluoro; R2 is a member selected or alternatively at 25° C. Isolation of the product in the from the group consisting of hydrogen, methyl and ?uoro; manner of Example 1 yields 3-keto-115-hydroxy-20,2‘1 R3 and R4 are members selected from the group consist diacetoxy-19-norpregnan-18-oie acid 11,18-lactone. 7 01 ing of hydrogen and methyl; and Ac is lower alkanoyl of 2,989,526 5 6 2 to 7 carbons, comprising oxidizing with ozone ‘a ster 5. The process of preparing a 3-keto-9a-?uoro-1l? oidal epoxide having the following fundamental structure: hydroxy-20,21-di-(lower alkanoyloxy) - allopregnane-18 O——-CH2 oic acid 11,18-lactone which comprises treating the corre CHIOAC sponding 9a-?u0rO-1 1,18-oxido-20,21-di-i(lower alkanoyl a oxy)-allopregnane-3-one with ozone. CHOAc 6. The process of preparing a 3-keto-11/8-hydroxy-16u methyl 20,2i1-die('1ower alkanoyloxy) -pregnane-l8-oic acid RI 11,18-lactone which comprises treating the corresponding R4 11,18-oxido—16u-methyl 20,21-di-(lower alkanoyloxy) 10 pregnane-B-one with ozone. 7. The process of preparing a 3-keto-6a-i?uoro 115 hydroxy~20,21~di~(lower alkanoyloxy)-pregnan-18 - oic i acid 11,18 lactone which comprises treating the corre H E sponding 6a-?uoro-11,18-oxido-20,21-di-(lower alkanoyl R2 15 oxy) -pregnan-3-one with ozone. wherein Ac and IR1_4 are as de?ned above. 8. The process of preparing a 3-keto-6?-?uoro llp-hy 2. The method of claim 1 characterized in that the dr0xy-20,21-di~(lower alkanoyloxy)-pregnan—18-oic acid oxidation reaction is run from about -—70° C. to about 11,18 lactone which comprises treating the corresponding 40° C. 6p-?uoro-11,18-oxido-20,21 - di - (lower alkanoyloxy) 3. The method of claim 2 characterized in that a liquid 20 pregnan-B-one with ozone. halogenated hydrocarbon solvent of less than 6 carbon 9. The process of preparing a 3-keto-6/8-methyl v1 1,B~ atoms is used. hydroxy - 20,21-di#(lower alkanoyloxy)-pregnan-18-oic 4. The process of preparing a 3-keto-11?~hydroxy acid 11,18 lactone which comprises treating the corre 20,21-di~(lower alkanoyloxy)-allopregnan-18~oic acid sponding 6,8-methyl-11,18-oxido-20,21-di-(lower alkanoyl 11,18-lactone which comprises treating the corresponding 25 oxy) -pregnan-3-one with ozone. 11,18-oxido-20,21-di-(lower alkanoyloxy)-a1lopregnan-3 one with ozone. No references cited.