US2888457A - Bismethylenedioxy steroids and methods of making same - Google Patents

Description

BISMETHYLENEDIOXY STEROIDS AND METHODS OF MAKING SAME Roger E. Beyler, Westfield, and Lewis H. Sarett, Princeton, N.J., assignors to Merck & Co., Inc., Rahway, NJ., a corporation of New Jersey No Drawing. Application August 18, 1958 Serial No. 755,403

31 Claims. (Cl. 260-23955) This invention relates generally to new compounds derived from steroids which have attached to the condensed ring nucleus a dihydroxyacetone side chain. More particularly it is concerned with new steriods in which a dihydroxyacetone side chain of a pregnane or unsaturated pregnane is deactivated by formation of a bismethylenedioxy derivative. It is further concerned with a method for making such new compounds from steriods having a free or esterified dihydroxyacetone side chain.

This application is a continuation-in-part of our copending application Serial No. 632,010, filed January 2, 1957, now abandoned. v

It is well known that the vast majority of physiologically-active steroids are members of the pregnane series having a free or esterified dihydroxyacetone side chain at the C-17 position. This side chain is subject to oxidation at -21, to reduction at 0-20, to rearrangement leading to a D-homo steroid and to decomposition under strongly acidic or basic conditions. Since such reactions and reaction conditions are often necessary to modify or introduce functional substituents in the nucleus of the steroid molecule, the ability to deactivate or block the dihydroxyacetone side chain is important for the practical synthesis of physiologically-active steroids. Some success has been achieved by forming C-ZO ethylenedioxy steroids but this blocking group is not completely satisfactory since it is quite acid labile and serves to deactivate only one portion of the dihydroxyacetone side chain, the ketone function.

It is an object of our invention to provide a new series of steroid compounds in which the dihydroxyacetone side chain of a pregnane or unsaturated pregnane is deactivated by a very stable group wherein all three of the carbon atoms in the dihydroxyacetone chain are protected. It is a further object to protect the side chain of 17a,21-dihydroxy-20-keto pregnanes and unsaturated derivatives thereof with a group that can be conveniently removed to regenerate the dihydroxyacetone moiety. A more specific object is to provide new derivatives of steroids'having a dihydroxyacetone side chain in which this functional moiety is protected by a bismethylenedioxy group. An additional object is a process for making this new type of steroid from a steroidv having the dihydroxyacetone side chain. Other and further objects will become evident from the detailed explanation of our invention hereinbelow.

.We have found that when a steroid having a dihydroxyacetone side chain attached to the condensed ring steriod nucleus is treated with formaldehyde in the presence of a strong acid there is obtained a bismethylenedioxy steroid in which all three carbon atoms of the dihydroxyacetone moiety are a part of at least one of the five-membered rings thus formed. We have also found that the presence of nuclear substituents or nuclear double bonds do not interfere with or prevent the formation of such bismethylenedioxy compounds. Thus, when the dihydroxyacetone moiety is at the 0-17 position of the nucleus, a compound is obtained having at carbons l' l, 20 and 21 the structure o-on, 21 EUR l The new process may then be pictured structurally as applied to a steroid of the pregnane series having a dihydroxyacetone side chain at C-17 as follows:

O-CH:

Bythe dihydroxyacetone side chain is meant the'17a hydroxy-20-keto-21-hydroxy moiety of a steroid such asI. We refer to such new steroids as 17-20,2021 bismethyl enedioxy steroids. Although the dihydroxyacetone moiety must be unsubstituted in order to react as shown above, the steroid actually charged to the reaction mixture may, if desired for convenience sake, be esterified at either or both of the hydroxy groups since' such ester groups are hydrolyzed under the reaction conditions.

It will be evident that a dihydroxyacetone side chain located at positions of the steroid condensed ring nucleus other than at C-17, e.g. atC-16, at C-17a in D-homo steroids, and at other positions in the nucleus may also be converted by treatment with formaldehyde under our reaction conditions to the corresponding bismethylene dioxy compounds. However, since the physiologicallyactive steriods known at the present time have this function at C-17, we will discuss primarily those compounds, which may be described as l7a,2l-dihydroxy 20-keto' steroids of the pregnane series.

17-20,20-2l bismethylenedioxy steroids of the pregnane series are prepared by treating a 17a,21-dihydroxy?20-' keto steroid of the pre'gnane series with formaldehyde in the presence of a strong acid. An excess of formaldehyde is employed in order to obtain the optimum yield of bis-dioxy compound.

In making a 17-20,20-2l bismethylenedioxy steroid we are able to use pure formaldehyde itself, the readily available 40% aqueous formaldehyde solution (forma-, lin) or other compounds which act as a source of formal-' dehyde in the reaction mixture. Paraformaldehyde, for-' mal and trioxane are examples of compounds which act as a source of formaldehyde.

The reaction is carried out in the presence of a strong acid, such as hydrochloric, perchloric, hydrobromic, sul-' furic, phosphoric and like acids. log k of less than 2.25 are considered strong acids for our process and any of these may be employed. The -log k of a large number of organic and inorganic acids appear in Langes Handbook of Chemistry, Handbook Publishers, Inc., 8th ed., 1952, pp. 1229-1233. This and similar tables in other texts provide ready informa tion as to the log k values of different acids so that acids suitablefor usein our invention may be determined readily. Lewis acids or formic acid may also be used; as the acid catalyst in preparing 17-20,20-2l bismethyb Acids which have "a assess? enedioxy'steroids' although the log k of formic acid is 3;75.

The reaction of a 17a,2 l-dihydroxy-20-keto steroid with formaldehyde is carried out in an organic solvent inertunder the reaction conditions. This may be a water-miscible solvent such as dioxane or tetrahydrofuran in which case the reaction takes place in a one-phase solvent system. Alternatively, and preferably formation of the 17-20,20-21 bismethylenedioxy steroid is effected in a two-phase reaction mixture wherein the steroid is dissolved in a water-immiscible organic solvent and the second phase is the aqueous acid-formaldehyde phase. Such an aqueouszorganic solvent two-phase reaction mixture is very satisfactory and is preferred for optimum yields under our operating conditions.- It. is desirable that both the starting material and the reactionproduct be soluble in the organic solvent, but satisfactory yields and quality of 17-20,20-21 bismethylenedioxy steroids are obtained when the end product is soluble and the starting 17,21- dihydroxy-20aketo-steroid is insoluble in the organic solvent. Suitable water-immiscible organic solvents for our process are chloroform, methylene chloride, ethylene dichloride, carbon tetrachloride, ethylene dibromide, methylene bromide, benzene, ethyl ether and the like, the chlorinated solvents being most satisfactory.

Formation of our new l7-20,20-2l bismethylenedioxy steroids of the pregnane series is ordinarily conducted at temperatures from about 30 C. to about +50 C. For ease of operation temperature of C. to about +35 C. are preferred and satisfactory yields are realized at such temperatures with most steroids.

' The time required for obtaining optimum. yields of l7-20,202l bismethylenedioxy steroids will depend to some extent on the particular reaction temperatureutilized. We have also found that the reaction time nec essary for good yields is a function of the type of. 1711,21.- dihydroxy-ZO-keto steroid employed as starting material. For instance, in a chloroform-formalin-hydrochloric acid reaction system, about 40-50 hours. are required for optimumconversion of cortisone to 17-20,20-2l bismeths ylenedioXy-4-pregnene-3,1l-dione, whereas only l530.

minutes are needed to convert prednisolone in high yield to l7-20,20-21 bismethylenedioxy-l,4-pregnadiene-11 8-01- 3-one.

This difference in steroid reactivity does not, however, present any serious difiiculty in readily determining the proper length of time to run the reaction under. any desired process condition. The course of conversionof the 171:,2l-dihydroxy-2o keto moiety of a steroid of the pregnane series to a l7-20,20-21 bismethylenedioxy derivative is readily followed. by use of the diam'sole hisdiphenyltetrazolium chloride reagent, commonly known as the B.T. reagent. This reagent reacts with a dihydroxyacetone grouping of a steroid to give a. deep blue solution. It does not form a blue color with the 17- 20,20-21 bismethylenedioxy steroids. By means of this B.T. test, therefore, the degree of reaction can be followed quantitatively, or if desired only semi-quantitative- 1y, since the intensity of the blue color is a function of the amount of 170:,21-dihYdI'0XY-20-k8t0 steroid present in the solution tested. This intensity of color can conveniently be measured against a known standard solution and the extent of reaction easily calculated. Use of the Blue Tetrazolium (B.T.) reagent in assaying for the presence of a dihydroxyacetone moiety is described more fully in a publication by Mader et al., Anal. Chem. 24, 666 (1952).

By the process discussed above, and where necessary following the course of reaction by the B.T. test, any 170:,21-dihYd1'OXY-20-k6t0 steroid of the pregnane series" may be converted to a 17-20,20.-21 bismethylenedioxy steroid.

Functional groups. or substituents in other parts of the pregnane molecule do not interfere with formation of the bismethylenedioxy side chain and in most cases are not themselves destroyed or modified under the reaction. conditions: Since strong" acid is present during the reaction, any unusually acid-sensitive substituents in other portions of the molecule might possibly react and we pre fer, where such side reactions are undesired and apt to occur, to temporarily form, iffeasible, an acid stable derivative of such substituents. In the case of ll-hydroxylated steroids, reactionat the ll-position may be substantially eliminated by carrying out our process in a solventisystern essentially free. of. alcohols, particularly the lower alkanols; Thus, in an alcohol free system, bydrocortisone and prednisolone are readily converted by treatment with formaldehyde and strong acid to 17- 20,20-21 bismethylenedioxy-4-pregnene-11/3-ol-3-one and 17-20,20-21 bismethylenediox -l,4-pregnadiene--01-3- one respectively. If alcohol should be present the l7- 20,20-21 bismethylenedioxy derivative, of course, forms but an alkoxymethyl ether derivative of the ll-hydroxy groupvis' also formed; Thisis, however, cleavedduring. removal of the bismethylenedioxy function.

Where functional substituents. in other parts of. the molecule, such as amines, are those that normally react with aldehydes, they will reactduring ourv process. This is not a serious difiiculty since in most instances-the original functional group can be regenerated readily.

We are able, therefore, to carry. out our new process on steroids of the pregnane series generally. Ordinarily, the steroid reactants will be substituted at the 3-position with an oxygen-containing function or a function reconvertible by hydrolysis to an oxygenated group, such as a keto or hydroxy group, or an ethylenedioxy, enamine, enol ether,

or ester moiety. The steroids may also have substituents such as hydroxy, keto, halo, ether or lower. alkyl groups-at.

other positions of the condensed ring nucleus; as for in stance at positions 1, 2,, 3, 4, 6, 7, 9, 11, 12, 14, 15 0111 6.

A preferred group of 17-20,20-2l bismethylenedioxy steroids of the invention have oxygenated functions at both;

the 3 and 11 positions of the condensedringsystem- Also: included within the preferred embodiments of the inverts tion are those bismethylenedioxy steroids having aihalogen group, such as chloro, bromo or fluoro, at the 9.-posi'-- tion of the ring. Our new compounds may be completely saturated or have one or more double bonds attached, forexample, to carbon. atoms 1, 4, 5, 6, 7, 11 or 14. For

example, there may be double bonds in the 1:2, 4:5, 5:6,. Some' 8:9, 9:11 and at other positions of the molecule. representative examples of new steroids made by the method of our inventionfromthe. corresponding. 17,21- dihydroxy-ZO-keto steroids. are- The desired products are isolated from the reaction mixture by extraction into an organic solvent followed by a chromatographic separation or by recrystallization from a suitable solvent. Certain of the 3,1l-bisoxygenated-17- 20,20-21 bismethylenedioxy ring A unsaturated steroids of the pregnane series have cortisone-like activity and may themselves be used in the treatment of diseases which respond to anti-inflammatory agents. For the most part, however, the greatest value of our new compounds lies in the fact that they represent intermediates in which the important C-17 dihydroxyacetone side chain is rendered chemically inert and inaccessible so that reactions and transformations which would destroy an unprotected dihydroxyacetone moiety may be used safely on other portions of the steroid molecule. For example, Claisen condensations at positions alpha to a carbonyl group may be carried out without undesirable reaction in the side chain. In this way Z-methyl cortisone or Z-methylhydrocortisone may be prepared from cortisone or hydrocortisone by first making the 17-20,20-21 bismethylenedioxy derivative, treating the resulting compound successively with methyl oxalate and a methylating agent, and finally treating the 2 methyl-l7-20,20-21 bismethyleizedioxy steroid with sulfuric acid to reverse the bismethylenedioxy function and obtain the Z-methyl cortisone or hydrocortisone. This process would not be feasible with an unprotected dihydroxyacetone side chain since extensive side reaction would occur at the 21-position.

Furthermore, after inactivation of the side chain by our method, it is now possible to treat a 17a,21-diol-20-keto steroid of the pregnane series having a nuclear carbonyl or oxide function with a metal alkyl or metal Grignard reagent thereby alkylating the nucleus without adverse reactions in the side chain. These new compounds also provide a convenient method for selectively reducing a carbonyl group in the A ring of the steroid nucleus without also reducing the ZO-keto substituent, and for selectively blocking, for any purpose, the 20-keto substituent of a 3,20-diketo steroid.

When the desired reactions have been performed on the steroid with the protected dihydroxyacetone side chain, the side chain can be readily regenerated by treatment of the l7-20,20-2l bismethylenedioxy compound with acid. This process of reforming the l7a,2l-dihydroxy-20-keto steroid of the pregnane series is more fully described in our copending application Serial No. 632,026, filed January 2, 1957.

The following examples are given for purposes of illustration and not by way of limitation:

EXAMPLE 1 .1 7-20,20-2I bismethylenedixy-4-pregnene-3,1I-di0ne 500 mg. of cortisone is suspended in 40 ml. of chloroform and 10 ml. of formalin (40% aqueous formaldehyde) and 10 ml. of concentrated hydrochloric acid are added. This two-phase system is stirred vigorously at room temperature for 52 hours. The aqueous phase is then made alkaline with aqueous sodium hydroxide, sepamelting point to 259262 C.

70. After re- 7 6 EXAMPLE 2 17-20,20-21-bismethylenedi0xy-4-pregnene-3,II-dione 500 mg. of cortisone free alcohol is suspended in 2 5 ml. of chloroform. To this mixture is added a solution of 10 ml. of concentrated hydrochloric acid and 10 ml. of formalin. The two-phase reaction mixture is stirred at room temperature for 19 hours, and at the end of this time, the chloroform layer is separated. It is washed with a saturated solution of sodium bicarbonate, dried and concentrated under vacuum to an amorphous residue. Upon treament with boiling methanol, a crystalline product separates weighing 328 mg. and having a melting point of 220-247 C. Further recrystallization from acetone-methylene chloride yields substantially pure 17-20,20-21-bismethylenedioxy-4-pregnene-3, ll-dione.

The same product is obtained when a methylene chloride solution of cortisone is heated with formalin and perchloric acid under the conditions described above.

, EXAMPLE 3 1 7-20,20-21-bismethylenedioxy-4-pregnene-3,1I-di0ne To a solution of 500 mg. of cortisone acetate in 25 ml. of chloroform is added a mixture of 10 ml. of formalin and 10 ml. concentrated hydrochloric acid. This two-phase reaction mixture is stirred at room temperature for 70 hours. At the end of this time, the chloroform layer is separated and the inorganic layer extracted with chloroform. This chloroform extract is added to the original chloroform layer and the solution washed with dilute soduim bisulfate, then dried over magnesium sulfate. The chloroform is removed under reduced pressure and an amorphous gum obtained, weighing 475 mg. After purification by chromatographing on acid washed alumina and elution with ether mg. of 17-20,20-2lbismethylenedioxy-4-pregnene-3,ll-dione is obtained.

In like manner 4,9(l1)-pregnadien-17a,21-diol-3,20- dione is converted to 17-20,20-21-bismethylenedioxy-4,9 1 1)-pregnadien-3-one, and 4-pregnen-l7a,2l-diol-3,20- dione 21-acetate to 17-20,20-21-bismethylenedioxy-4- pregnen-B-one.

EXAMPLE 4 1 7-20,20-21-bismethylenedioxy-4-pregnene-11fi-ol-3-0ne 17-20,20-21-bismethylenedioxy-4-pregnene-3J1-dione To 500 mg. of hydrocortisone suspended in 25 ml. of chloroform is added a mixture of 10 ml. of formalin and 10 ml. of concentrated hydrochloric acid. The twophase reaction mixture is stirred at room temperature for a period of 72 hours. At the end of this time, the layers are separated and the inorganic layer washed with chloroform. The combined chloroform extracts are washed with a saturated solution of sodium bicarbonate and then dried and concentrated under reduced pressure. The resulting gum is chromatogramed on acid washed alumina and washed alumina and a non-crystalline product obtained which is negative in the B.T. test and has the infrared spectrum expected for l7-20,20-2l-bismethylenedioxy-4-pregnene-1 1 fl-ol-3-one.

This non-crystalline material is dissolved in 2 ml. of acetic acid and to this solution is added 60 mg. of chromium trioxide. The reaction mixture is allowed to stand at room temperature for ten minutes and at the end of this time, 5 ml. of water added'to the mixture. The mix ture is extracted several times with methylene chloride, the methylene chloride extracts washed with dilute sodium bicarbonate, then dried and concentrated to yield 17-20, 20-21-bismethylenedioxy-4-pregnene-3 1 1-dione.

EXAMPLE 5 v 17-20,20-21-bismethylenedi0xy-1,4-pregnadiene-3,I1- dione To a suspension of 500 mg. of prednisone in .25 .ml. of chloroform is added a mixture of 10 m1. of formalin .the original organic phase. I solution is washed with a saturated solution of sodium hi- I washed alumina and eluted with ether. the ether gives the desired compound which, when crystallized from methanol, has melting point 239-243 C. (dec.) I

and thetwo layers are then separated. The aqueous .layer is extracted once with chloroform and the chloroform extract combined with the original organic solvent layer.. The chloroform is Washed with a saturated solution of sodium bicarbonate, dried and concentrated under reduced pressure to a semi-crystalline solid Weighing 712 1mg. This crude product is triturated with boiling .methanol and 352 mg. of crystalline material obtained,

melting point 175-195" C. After recrystallization of this material from acetone and methanol, a pure sample of 17-20,20-2l-bismethylenedioxy 1,4 pregnadiene 3,11-

dione, melting point 2l4-217 C., is obtained.

. The same product is obtained by using sulfuric acid in place of hydrochloric acid.

EXAMPLE 6 Pr epara tibiiof i120,20-ZI-biSmethyIenediOxy-I,ipreghadiene-I1,B-bl-3-0ne-1I-methoxymethylether To a suspension of 500 mg. of prednisolone in 25 ml. of chloroform is added a mixture of 10 ml. of formalin and 10 ml. of concentrated hydrochloric acid. This twophase system is stirred at room temperature for a period of 45 hours. At the end of this time, the two layers are separated. The aqueous layer is extracted once with chloroform and the chloroform extract combined with The combined chloroform carbonate,, dried and concentrated under reduced pres- .sure to ,a semi-crystalline solid weighing 500 mg. This product is recrystallized from methanol to yield 300 mg. .of product, melting at 191202 C. Recrystallization from acetone and methanol gives a pure sample of 17-20,

20-21 -'bismethylene-dioxyl-l,4-pregnadiene 11,3 ol 3- one-ll methoxymethylether, melting point 217220 C.

is stirred in a nitrogen atmosphere for one-half hour. 2.5 ml. of a 2 N methanolic solution of sodium methoxide is .added and stirring continued for five minutes. 0.3 ml. of

water is then added and stirring continued for an additional five minutes, and the solutionthen acidified with acetic acid. The solvent is removed under reduced pressure, the residue dissolved in chloroform and the chloroform extracted in sequence with water, 10% sodium bicarbonateand finally with water. The chloroform solution isdried over sodium sulfate and the solvent removed ,..under reduced pressure to give 1.09 grams of crude 4,6-

pregnadien-17m,21-diol-3 ,11,20-trione.

A mixture of this diol, 50 ml. of chloroform, 20 ml. of concentrated hydrochloric acid and 20 ml. of formalin .is stirred vigorously at room temperature for 64 hours.

50 ml. of chloroform and 50 ml. of water are then added,

I the layers separated, and the organic phase washed in se- .quence with water, 10% sodium bicarbonate and again with water. After drying with sodium sulfate, the chloroform is removed under reduced pressure to give a residue of 17 20,20 21 bismethylenedioxy 4,6 pregnadiene- 3,1l-dione., This product is dissolved in benzene, adsorbed on acid Evaporation of and lal +ll9 (chloroform).

Following the reactionconditions described in paragraphs two and three above, and using benzene as the organic solvent and hydrobromic acid in place of hydro I chloric acid, 17- 20,20-2l-bismethylenedioxy-6-methyl-9a- I fiuoro-l,4-pregn'adiene-'llpt-ol-3-one is obtained from 6- 3,20-dione. I

EXAMPLE 8 I7 20,20 21 bismethylenedioxy 1,4 p regn'izd ie he- 11fi-0l-3-0ne Toa suspension of 500 mg. of 1,4-pregnadiene-llfll7a,2l-triol-3,20-dione in 25 ml. of chloroform is added a mixture of 10 ml. of formalin and 10 ml. of concentrated hydrochloric acid. The reaction mixture is stirred vigorously at room temperature for one hour and at the end of this time, the chloroform layer is separated and Washed with a saturated solution of sodium bicarbonate. It is dried and concentrated under reduced pressure to give a gum which crystallizes upon trituration with boiling methanol. This product is recrystallized several-times from ethyl acetate to yield l7-20,20-2l-bismethylene dioxy-1,4-pregnadiene-l l {3-01-3 -one.

EXAMPLE 9 17 20,20 21 bismethylenedioxy 9oz -fluo ro 4'' pie mane-11 fl-0l-3-0ne Five grams of 9e-fluorohydrocortisone acetate are'dis- I solved in 250 ml. of chloroform. To the stirred solution is added 100 ml. of concentrated hydrochloric acid'and 100 ml. of 37% aqueous formaldehyde (formalin). After stirring at room temperature for 18 hours, the chloroform layer is separated, washed with saturated sodium bicarbonate, dried and evaporated to dryness. Trituration of the oil with methanol gives 1.1 grams of l7-20,20 -2lbisrnethylenedioxy 90c fiuoro 4 pregncne 1118 01- 3-one,melting point (245) 248-255 C.

"dissolved in one liter of chloroform and to this stirred solution is added 400 ml. of concentrated hydrochloric acid and 400 ml. of formalin. The reaction mixture is stirred at room temperature for one hour and worlted up as described in Example 9. "The product "melts at 250-260 C.,'285290 C.

EXAMPLE l1 Hydrolysis and acetylation of 17-20,20-2l-bismethyiehedi0xy-4-pregnene-3JI-dione t0 corlisone acetate To mg. of the bismethylenedioxy derivative obtained as in Example 1 is added 5 ml. of methanol and 5 ml. of 5 N sulfuric acid and the heterogeneous mixture refluxed on the steam bath for one hour (homogeneous after 45 minutes). The methanol is removed in vacuo and the resulting aqueous solution thoroughly extracted with ethyl acetate. The extract is washed with sodium bicarbonate, dried and concentrated to give 96 mg. of residue. This is dissolved in 0.3 ml. of pyridine and 0.3 ml. of acetic anhydride. The mixtureis heated for ten minutes on the steam bath and poured into Water. The resultant mixture is extracted several times with methylene chloride, the methylene chloride washed with dilute hydrochloric acid and sodium bicarbonate, dried over magnesium sulfate and evaporated. The residue is recrystallized from acetone to give cortisone acetate.

EXAMPLE l2 1 7-20,20-21 -bismethylenedioxy- -pregnene-lfi-ol-3 orte separated, the aqueous layer extracted with chloroform and the solution combined. They are washed With sodium bisulfate, dried and concentrated in vacuo. .The entire residue is chromatographed on acid Washed'alu- Elution of the column with 1:4 petroleum ethermina.

. for two hours.

' fate.

17-20,20-21-17ismethylenedioxy-4-pregnene-11fl-0l-3-one EXAMPLE 14 17-20,20-21 bismethylenedioxy-9u-chloro4-pregnene-1113- l-3-0ne Ten grams of 9,11fi-oxido-4-pregnen-17a-21-diol-3,20- dione are suspended in 500 ml. of methylene chloride and to this mixture is added 20 ml. of hydrochloric acid and 20 ml. of formalin. The reaction is stirred at room temperature for 90 minutes. Isolation of the reaction product as described above yields seven grams of 17-20,20-21 bismethylenedioxy-9a-chloro-4-pregnene-l1B o1 3 one, melting point 180-190" C. Recrystallization from methylene chloride-methanol gives pure material, melting point 220230 C.

EXAMPLE 15 i 7 -20,2 0-21 bismethylenedioxy-1-pregnene-3,1 1 -dione A mixture of four grams of 1-pregnen-17 0:,21-di0l- 3,11,20-trione, 200 ml. of chloroform, 80 ml. of concentrated hydrochloric acid and 80 ml. of formalin is stirred vigorously at room temperature for 48 hours. At the end of this time the chloroform layer is separated and washed with three small portions of 5% potassium carbonate and then with water until the Water washings are neutral.

The chloroform solution is dried over magnesium sulfateand the solvent removed in vacuo. There is obtained a light yellow oily solid. On crystallization of this material from acetone and recrystallization from methylene chloride-methanol substantially pure 17-20,20-21 bismethylenedioxy 1 pregnene-3,ll-dione, melting point 230-233 C., is obtained.

EXAMPLE 16 17-20,20-21 bismethylenedioxy-allopregnane-11fi-ol- To a solution of 7.1 grams of allopregnane-ll;8,17a,2ltriol-3,20-dione in 350 ml. of chloroform is added 140 ml. of cold concentrated hydrochloric acid and 140 ml. of cold neutral formalin. The two-phase mixture is stirred The solvent layers are separated and the' aqueous phase extracted with two 100 ml. portions 'of chloroform. The chloroform solutions are combined, washed successively with water, 5% sodium bicarbonate and water, and then dried over anhydrous magnesium sulone-ll-methoxymethylether; further elution with ethyl ether gives l7-20,20-21 bismethylenedioxy-allopregnane- -ll}8-ol-3-one, melting point 220-225 C., after recrystallization from ether.

Following the procedure set forth in the above para- The chloroform is then removed in vacuo and the graph and starting with 6.5 grams of 9a-fluoro-L4-pregnadiene-l1;8,l7a,2l-triol-3,20-dione there is obtained 17-20,20-21 bismethylenedioxy-9tat-fluoro-1,4-pregnadiene- 1 1,8-01-3 -one.

EXAMPLE 17 17-20,20-21 bismethylenedioxy- I-pregnan-3-dne 500 mg. of 4-pregnen-17u,21-diol-3,20-dione in 25 ml. of chloroform is added to a mixture of 10 ml. of concentrated hydrochloric acid and 10 ml. of formalin. The

resulting two-phase system is stirred at room temperature for 44 hours. At the end of which time the phases are separated and the aqueous phase extracted with two 25 ml. portions of chloroform. The chloroform extracts are combined, washed with aqueous sodium bicarbonate and with water, dried and finally distilled. The residual solid is washed with petroleum ether to give 327 mg. of 17-20,20-21 bismethylenedioxy-4-pregnen-3-one, melting point 220245 C. Recrystallization from methanol and methylene chloride-ether raises the melting point to 250- 255 C.

In a similar fashion by employing 4,9(11)-pregnadien- 17a,21-diol-3,20-dione as the starting material and using sulfuric in place of hydrochloric acid, there is obtained 17 20,20-21 bismethylenedioxy-4,9(11)-pregnadien-3- one, melting point 218222 C.

EXAMPLE 18 17-20,20-21 bismethylenedi0xy-9ot-chlora-4-pregnene- 11p-0l-3-0ne One gram of 9a-chloro hydrocortisone acetate in ml. of methylene chloride is added to a pre-cooled mixture of 25 ml. of methanol free formaldehyde in 25 ml.

of concentrated hydrochloric acid. The reaction mixture EXAMPLE 19 17-20,20-21 bismethylenedioxy-9m-bromo-4- pregnene-11fl-0l-3-one To a stirred solution of 1.6 grams of 9,11-oxido-4- pregnen-17a,2l-diol,3-20-dione in 100 ml. of chloroform is added a cold mixture of 50 ml. of formaldehyde and 50 ml. of 40-42% hydrobromic acid. The reaction mixture is stirred at room temperature for 4 /2 hours. At the end of this time the chloroform layer is separated, washed with water and sodium bicarbonate solution, and dried. The chloroform is then removed in vacuo and the residual oil triturated with methanol. Crystals of 17- 20,20-21 bismethylenedioxy-9a-bromo-4-pregnene-llB-ol- 3-one are obtained which, after recrystallization from methanolmethylene chloride, melts at -177 C.

Oxidation of this substance with pyridine-chromium trioxide complex yields 17-20,20-21 bismethylenedioxy- 9a-bromo-4-pregnene-3, 1 l-dione.

EXAMPLE 20 17-20,20-21 bismethylenedioxy-I6u-methyl-4- pregnene-3,1 I -dione ring 237 ml. of 37% hydrochloric acid and 237 ml. of 37% formaldehyde. This mixture is stirred at room temperature for 70 hours. The chloroform layer is then sep 11B-ol-3-one, melting point 275279 C. that the reaction medium employed in making this substance be substantially methanol-free.

assess? ares are the 'jaqueeus layer xuaetea twice with "50 m1. of chloroform. The chloroform solution and extracts'are combined, washed with saturated sodium bicarbonate solution and with Water. The chloroform solution is then dried over magnesium sulfate and concentrated in vacuo until crystallization occurs. The resulting slurry is flushed with 100 ml. of methanol to remove the chloroform and then dissolved in approximately 200 ml. of methanol. The methanol solution is concentrated in vacuo to a volume of about 75 ml. and cooled to 5 C. The slurry is filtered and the crystalline material washed with cold methanol to give 17-20,20-21 bismethylenedioxy-loamethyl-4-pregnene-3,ll-dione, melting point 231236 C.

The same product is obtained when sulfurous acid is used-in place of hydrochloric acid as the acid catalyst.

EXAMPLE 21 17 20,20-2 1 Eisinethylenedi0xy-16m-methyl-4- pi-eghene-I 1 fi-0l-3-one A mixture of 47.5 ml. of formaldehyde (low in meth- -anol content) and 47.5 ml. of concentrated hydrochloric acid are added at 0' C. to a solution of 5 grams of 16amethyl hydrocortisone in 182 ml. of methanol-free chloroform. The mixture is stirred at room temperature in a nitrogen atmosphere for 24 hours. The chloroform layer is then separated and the aqueous layer extracted with chloroform. The chloroform solutions are combined, washed with two 50 ml. portions of water, sodium bicarbonate solution and water. The chloroform solution is then dried over magnesiurn sulfate, filtered and concentrated to dryness. The residue is triturated with "cold methanol and the crude solid thus obtained is dissolved in 215 ml. of benzene and chromatographed on 400 mg. of Florosil, elution with acetone in nhexane and concentration of these fractions yields 17- 20,20-21 bismethylenedioxy-16a-methyl-4-pregnene-11,8-

ol-3-one, melting 278283 C.

The llfl-methoxy methyl ether of said substance is obtained on elution of the column with 7% acetone in n-hexane, melting point 240-243 C. after recrystallization from chloroform-hexane.

' EXAMPLE 22 conditions of Example 7 hereinabove there is obtained 1 7-20,20-2l bismethylenedioxy-6u methyl-4 pregn'ene- It is important EXAMPLE 23 1 7-2 0,20-21 bismethylenediaxy-I 6 B-methyl-4-pregnene- 3 ,1 1 -di0ne temperature for 20 hours, followed by addition of 960 ml. of Water. The layers are separated and-the aqueous layer extracted with three 200 ml. portions of methylene chloride. The combined methylene chloride layer and extracts are washed with 200 ml, of water and excess potassium bicarbonate, and two 200 ml. portions of 'waterytney are dried over magnesinum sulfate and taken to dryness in vacuo (fiush'ed'twice with benzene). The residue is triturated with ether 'to yield 6.69 grams of crystalline 17-20,20-21 bismethylenedioxy-l6B-methyl-4- pregnene-3,11-dione, melting point 220-247 C. (dec.).

The starting material for making this material is prepared as follows:

To a solution of 3a-acetoxy-l6-pregnene-11,20-dione in a mixture of tetrahydrofuran and ethyl ether is added diazomethane to produce 3a-acetoxy-16or,'17ot-methyleneazopregnane-11,20-dione (melting point 186190 C.) which precipitated from solution. Heating this compound at about 180 C. in vacuo produces 3ct-acetoxy-l6-methyl- 16-pregnene-ll,20-dione (melting point 165167 C.) which upon reaction with hydrogen peroxide in the presence of sodium hydroxide in methanol solution for :18 hours at room temperature affords 16a,17a-epoxy-3ahydroxy-16,9-methyl-pregnane-l1,20-dione (melting point 178-180 C.). When this compound is treated with perchloric acid in aqueous dioxane at 2530 C. for 65 hours and the resulting reaction mixture is diluted with water a mixture of 3a,17a-dihydroxy-l6-rnethyl-15- pregnene-11,20-dione and 3a,17oc-dihydr0xy-l6-methylene-pregnane (melting point 158167 C.) is precipitated and recovered by filtration. Reduction of this mixture with hydrogenin methanol in the presence of palladiumcalcium carbonate catalyst affords a mixture of 3a,17a dihydrox-16 x-methylpregnane-11,20-dione and 30:,17adihydroxy-l6B-methylpregnane-11,20-dione sintering at C. Bromination of this mixture with bromine in chloroform at 4045 C. affords a mixture of 2l-bromo- 3a,17a dihydrox -16a-methylpregnane-11,20-dione and 21 bromo-3a,17u-dihydroxy-16,8-methylpregnane-l1,20- dione which upon reaction with potassium acetate and potassium iodide in acetone produces a mixture of 3a,17a,21-trihydroxy-lGti-methylpregnane-l1,20-dione 21- acetate and 3a,l7a,2l-trihydroxy-loa-methylpregnane- 11,20-dione 21-acetate. To a solution of this mixture in aqueous t-butanol at 10--15 C. is added N-bromosuccinimide to produce a mixture of 17a,21-dihydroxy-16umethylpregnane-3,l1,20-trione 21-acetate and 17a,2l-dihydroxy 16p methylpregnane-3,11,20-trione 2 l-acetatc which on chromatography on neutral alumina and elution with chloroform-benzene (1:1) and benzene yields 17a,2l-dihydroxy-16/9-methylpregnane-3,11-20-trione 21- acetate (melting point 2l02l3 C.). Reaction of this compound with bromine in a mixture of acetic acid and chloroform affords the corresponding 4-bromo compound (melting point -170" C. dec.) which is converted by reaction with semicarbazide to the 3-semicarbazone of 17a,21-dihydroxy 16B methyl-4-pregnene-3,11,20-trione 21-acetate. Treatment of this compound with a mixture of acetic acid and pyruvic acid gives 1706,21-dil'lYdl'OXY- 16B-methyl-4-pregnene-3,11,20-trione 21-acetate (melting point 226-232 C.). This latter substance is then hydrolyzed to the C-21 free alcohol by treatment with potassium bicarbonate or potassium hydroxide in aqueous methanol.

EXAMPLE 24 17-20,20-21 bismethylenedioxy-I6B-methyl-3-ethylenedioxy-5-pregnen-1 1 -one 17.5 grams of 17-20,20-21 bismethylenedioxy-lfi/S- methyl cortisone (prepared as in Example 23) is dissolved in 890 ml. of benzene, 45 ml. of ethylene glycol and 1.78 grams of p-toluene sulfonic acid, and the mixture heated at reflux for 17.5 hours. During this time a water separator is used to remove the water as it distills. The reaction mixture is then cooled to 20 C., washed with two 200 cc. portions of water, 200 cc. of saturated sodium bicarbonate solution and 200 cc. of Water, The organic layer is dried over anhydrous magnesium sulfate and concentrated to a solid. The solid after trituration with ether yields 12.4 grams of 17-20,20-2l bismethylenedioxy-l 6B-methyl-3-ethylenedioxy-5 -pregr1en-1 l-one.

13 EXAMPLE 2s 17-20,20-21 bismethylenedioxy-1 6fl-m ethyl-L4-pregnadime-3,1 1 dione with three 25 ml. portions of methylene chloride. The

combined methylene chloride ,layer and extracts are washed with 35 ml. of aqueous potassium bicarbonate" and three ml. portions of water, dried over anhydrous magnesium sulfate and concentrated to dryness in vacuo. The residue is flushed with benzene, during which process it crystallized. The yield of crystalline -17-20,20-21 bismethylenedioxy 1613 methyl 1,4 pregnadiene-' 3,11-dione is 1.28 grams.

The 16,8 methyl 1,4 pregnadien 17a,21 diol- 3,11,20-trione is prepared by treating 16,8-methyl-4- pregnen-'17a ,21-diol-3,11,20-trione 21-acetate with selenium dioxide in t-amyl alcohol, and then saponifying the ZI-acetate ester by warming in methanolic potassium bicarbonate.

EXAMPLE 26 17-20,20-21 bismethylenedioxy9a-fluor0-4-pregnene-3,1 1-

dione When 9a-fll10l'0 cortisone is treated according to the procedure set forth in Example 18, using sulfuric acid in place of hydrochloric acid, there is obtained 17-20, 20-21 bismethylenedioxy-9a-fluoro-4-pregnene-3,1 l-dione, melting point 275-290 C,

EXAMPLE 27 17 20,20 21 bismethylenedioxy 3 pyrrolidyl 3,5- pregnadien-I 1 one 500 mg. of 17-20,20-21 bismethylenedioxy-4-pregnene- 3,11-dione is dissolved in about 10 ml. of ethanol containing a little methylene chloride. This is concentrated to about 5 ml. to remove methylene chloride. To the concentrate is added 0.5 ml. of pyrrolidine and the mixture heated for one minute on the steam bath. The resultant precipitate is cooled and filtered, and washed with ethanol to give 540 mg. of light yellow prisms, melting point 205- 212 C. (dec.), of 17-20,20-21 bismethylene-dioxy-3- pyrrolidyl-3,S-pregnadien-l l-one.

Any departure from the above description which conforms to the present invention is intended to be included within the scope of the claims.

What is claimed is:

1. 17-20,20-21 bismethylenedioxy pregnanes having at the 3-position a substituent selected from the class consisting of keto and hydroxy groups and groups convertible thereto by hydrolysis, and having at the ll-position a substituent selected from the class consisting of hydrogen, hydroxy and keto groups; and unsaturated derivatives thereof.

2. 17-20,20-21 bismethylenedioxy pregnanes having at the 3-position a substituent selected from the class consisting of keto and hydroxy groups and groups convertible thereto by hydrolysis, having at the 9-position a substituent selected from the class consisting of halo and hydroxy groups, and having at the ll-position a substituent selected from the class consisting of hydroxy and keto groups; and unsaturated derivatives thereof.

3. 17-20,20-21 bismethylenedioxy pregnanes having at the 3-position a substituent selected from the class consisting of keto and hydroxy groups and groups convertible thereto by hydrolysis, having at the 9-position a substituent selected from the class consisting of hydrogen, .halo and hydroxy groups and at the ll-position', a

substituent selected from the class consisting of hydrogen, 4

hydroxy and keto groups and having at the 16-position a lower alkyl group; and unsaturated derivatives thereof having atleast one ring A double bond.

4. 17-20,20-21 bismethylenedioxy pregnanes having an oxygenated function at the 3-position; and nuclearly unsaturated derivatives thereof.

5. 17-20,20-21 bismethylenedioxy 4 pregnene 3,11- dione.

6. 17-20,20-21 bismethylenedioxy 4 pregnene-llp-ol- 3-one.

7. 17-20,20-21 bismethylenedioxy 1,4 pregnadiene-3, ll-dione.

8. 17-20,20-21 bismethylenedioxy-1,4-pregnadiene-11pol-3-one.

9. 17-20,20-21 bismethylenedioxy-9a-fluoro-4-pregnene- 11fi-ol3-one.

10. 17-20,20-21 bismethylenedioxy-9a-fluoro-1,4-pregnadiene-l 1/8-ol-3-one.

11. 17-2o,20-21 bismethylenedioxy-16-rnethyl-4-pregnene-3,1 l-dione.

12. 17-20,20-21 bismethylenedioxy-16e-methy1-4-prcgnene-11B-ol-3-one.

13. 17-20,20-21 bismethylenedioxy-16-methyl-1,4-pregnadiene-l 1 13-01-3 one.

14. l7-20,20-2l bismethylenedioxy-9oc-fluoro-16-rnethyl-l,4-pregnadiene-1 1,8-ol-3-one.

15. 17 -20,20-21 bismethylenedioxy 16p methyl-1,4- pregnadiene-3,l l-dione.

16. The process for preparing a 17-20,20-21 bismethylenedioxy steroid that comprises reacting a member of the class consisting of 3-oxygenated-17a,21-dihydroxy- 20-keto pregnanes and unsaturated derivatives thereof with formaldehyde in the presence of an acid selected from the class consisting of acids having a --log k of less than 2.25 and formic acid.

17. The process of claim 16 wherein the acid is a mineral acid.

18. The process for preparing a 17-20,20-21 bismethylenedioxy steroid that comprises reacting a member of the class consisting of 3,11-bisoxygenated-17u,2l-dihydroxy-ZO-keto pregnanes and unsaturated derivatives thereof with formaldehyde in the presence of an acid selected from the class consisting of acids having a log k of less than 2.25 and formic acid.

19. The process for preparing a 17-20,20-21 bimethylenedioxy steroid that comprises reacting a member of the class consisting of 16-rnethyl-3,1l-bisoxygenated-Ua, 2l-dihydroxy-20-keto pregnanes and unsaturated derivatives thereof with formaldehyde in the presence of an acid selected from the class consisting of acids having a log k of less than 2.25 and formic acid.

20. The process which comprises reacting 4-pregnen- 17a,21-diol-3,l1,20-trione with formaldehyde in the presence of an acid selected from the class consisting of acids having a log k of less than 2.25 and formic acid to produce 17-20,20-21 bismethylenedioxy-4-pregnene-3, ll-dione.

21. The process which comprises reacting 4-pregnen- 17a,2l-diol-3,l1,20-trione with formaldehyde in the presence of hydrochloric acid in an aqueouszorganic solvent two-phase reaction medium to produce 17-20,20-21 bismethylenedioxy-4-pregncue-3, 1 l-dione.

22. The process which comprises reacting 1,4-pregnadien-17a,21-diol-3,l1,20-trione with formaldehyde in the presence of an acid selected from the class consisting of acids having a log k of less than 2.25 and formic acid to produce 17-20,20-21 bismethylenedioxy-1,4-pregnadiene-3,1 l-dione.

23. The process which comprises reacting 1,4-pregnadiene-llfl,l7a,21-triol-3,20-dione with formaldehyde in the presence of an acid selected from the class consisting of acids having a log k of less than 2.25 and formic assess? :"acld'to produce 17-20;20?21 .bismethylenedioxy-l,4-preg- 'nadiene-l'lfi-ol-B-one.

24. The process which comprises reacting 9u-fiuor0-4- "pregnene-l1,8,17a,21-triol-3,20-dione with formaldehyde in the presence of an acid selected from the class consisting of acids having a -log k of less than 2.25 and formic acid to produce 17-20,20-21 bismethylenedioxy- 9a-fluoro-4-pregnene-l 1 B-ol-S-one.

25. The process which comprises reacting 16-rnethyl- 4 pregnen 17,2l diol 3,11,20 trione With form- 'aldehyde in the presence of an acid selected from the class consisting of acids having a log k of less than 2.25 and formic acid to produce 17-20,20-21 'oisrnethylenedioxy 16 methyl 4 pregnene 3,11 dione.

26. The process which comprises reacting 16-n1ethyl- 4-pregnen l7zx,21 diol 3,11,20 trione With formaldehyde in the presence of hydrochloric acid in an vaqueonsmrganic solvent two-phase reaction medium to formic acid to produce 17-20,20-21 bismethylenedioxy- 16a-methyl-4-pregnene-1 1 61-01-3 -one.

28. The process which comprises reacting 16-methyl- 1 I i F Au 1,4 pregnadiene 11fl,l7a,21 triol 3,20 dione with formaldehyde in the presence of an acid selected from the class consisting of acids having a log k of less than 2.25 and formic acidto produce 17-20,20-21 bismethylenedioxy-16-methyl-1,4-pregnadiene 11fi-ol-3-one.

29. The process which comprises reacting 9oz-fill0l'0- 16 methyl 1,4 pregnadiene 1l}8,17oz,21 triol 3,20- dione with formaldehyde in the presence of an acid selected from the class consisting of acids having a log k of less than 2.25 and formic acid to produce 17-20,20-21 bismethylenedioxy 9a fluoro .1 6 methyl 1,4 pregnadiene-11fl-ol-3-one.

30. The process which comprises reacting 9a-fluoro-16- methyl 1,4 pregnadiene 11/3,17a,21 triol 3,20- dione with formaldehyde in the presence of hydrochloric acid in an aqueousmrganic solvent two-phase reaction medium to produce 17-20,2()- 21 bisrnethylenedioxy-9afluoro 16 methyl 1,4 pregnadiene 11B ol 3 one.

31. The process which comprises reacting 16fi-methyl- 1.4 pregnadien 170 ,21 triol 3,11,20 t rione with formaldehyde in the presence ofan acid selected from the class consisting of acids having a log k of less than2.25 and formic acid to produce 17 20,20-21 bismethylenedioxy-l65-methy1-1,4-pregnadiene-3,1 l-dione.

No references cited.

Claims (1)

1. 17-20,20-21 BISMETHYLENEDIOXY PREGANANES HAVING AT THE 3-POSITION A SUBSTITUENT SELECTED FROM THE CLASS CONSISTING OF KETO AND HYDROXY GROUPS AND GROUPS CONVERTIBLE THERETO BY HYDROLYSIS, AND HAVING AT THE 11-POSITION A SUBSTITUENT SELECTED FROM THE CLASS CONSISTING OF HYDROGEN, HYDROXY AND KETO GROUPS; AND UNSATURATED DERIVATIVES THEREOF.