Kovember, 1963 KOTES 793

separated off. Repeated recrystallizations from ether-hexane gave an analytical sample: m.p. 246'; infrared absorption maxima vmal 1621, 1600, 1567, 1471 (shoulder), 1445, and 1420 (shoulder) cm.-l; ultraviolet absorption X,,, 256 nip, ( e 5700).

Anal . Calcd. for C16H240NT2: C, 73.80; H, 9.29; N, 10.76. Found: C,73.60; H,9.20; S, 10.60.

Acknowledgment.-The authors are indebted to Dr. R . I . Dorfman for the endocrinological assays.

Steroidal [17,l6-c]Pyrazoles

C. H. ROBIN SON,^ X, F. BRUCE, AND E. P. OLIVETO

Satirral Products Research Department, Schfring Corporation, Bloomnjield, Kew Jersey

Rewived J u n e Y , 1963

Some years ago, as part of a search for modified estrogens which might show useful lipid-shifting activity and a minimum of feminizing properties, a number of estrogen analogs bearing heterocyclic rings fused a t positions 16 and 17 were synthesized in these Labora- tories. The purpose of this article is to describe the preparation and properties of one such group of modi- fied estrogens, the 1,3,5 (1 0) -estratrieno [ 17,16-c ]py- razoles.

After this manuscript was completed, a publication2 appeared in whirh compounds IIa-d (Chart I) were

CHART 1

RO I a R = H I1

h R = C H , a R = R 1 = H b R = H; R = CHI c R = CH3; R ' = H d R = R ' = C H I

N/r' 1

RO &" a R = CHI; R' = CH$O b R = CHaCO; c R = CHBCO;

R' = CHICO R' = CHa

described. The experimental procedures involved2 [the action of hydrazine or methylhydrazine in ethanol on 16-hydroxymethylene estrone3 (Ia) or the corre- sponding 3-methyl ether4 I b ] were essentially the same as those used in our work.

The compounds IIa-c could each be methylated (dimethyl sulfate-potassium hydroxide) to give one and the same [ 17,16-c IN-methylpyrazole (IId).

(1) Dept. of Pharmacology, The Johns Hopkins Medical School, Balti-

( 2 ) P. de Ruggieri, C. Gandolfi, and D. Chiaramonti, Gazz. chim. ital., 93,

(3) L. Ruzicka, V. Prelog, and J . Battegay, Hell, . Chim. Acta, 31, 1246

(4 ) .I. C. Bardhan, J . Chem. Soc., 1848 (1936).

more 5 , Maryland.

269 (1963).

(1948).

The E-acetyl compounds (IIIa and b) were prepared by the action of hot acetic anhydride on IIc and IIa, respectively. Acetylation a t C-3 of the [17,16-c]- S-methylpyrazole (IIb) gave IIIc. The physical properties of all these compounds are collected in Table I.5

The ultraviolet spectra require some comments. Steroidal [3,2-c]pyrazoles with saturated A-rings have been reported6 to show A:::" 223 nip (e - 5,000) in accord with the absorption shown by simple pyra- zoles.7,8 I n the cases a t hand, t'he maximum a t 222- 223 mp ( E - 14,000-15,000) is att'ributed to summa- tion of the E-band of the aromatic A-ring and the pyrazole absorption. Indeed, this was simply deinon- strated as follows : a solution containing equimolar amounts of estrone 3-methyl ether and 3p-hydroxy-5- androsteno[l7,16-c]pyrazoleg [IVa; A::,"" 223 mp (e 6,500)] showed the same maximum a t 222 nip ( e 15,500) as did 3-methoxy-1,3,5 (10)-estratrieno [ l7,lG-c 1- pyrazole (IIc), along with the normal 278 and 288 mp maxima due to the aromatic A-ring.

The N-acetylpyrazoles (IIIa and b) as well as the 5androsteno [17,16-c]?;-acetylpyrazoles IVb showed A,,, 255 nip ( e - 21,000), in good agreement with the values recorded for an K-acetyl androstano [3,2-c]- pyrazole6 [A?,"," 258 nip ( e 19,000)] and for simple X-acylpyrazoles.8t lo

The infrared absorptions due to the ?;-acetyl group in I I Ia and b appeared a t 5.82 p, and in the case of com- pound IVb a t 5.75 p. These absorption peaks differ quite markedly from those due to the >SCOR sys- tem" (-6.0-6.14 p) and the >C=?;SICOR system1? (-6.0 p). However, the C=O absorptions of a number of X-acylpyrazoles have been recorded by Ried and Konigstein13 who found, for example, t'hat X-propionyl- 3,5-dimethylpyrazole showed Amax 1722 cm. -l (5.81 p).

The shift to lower wave length of the C=O absorption in going from t'he system >?;COR to systems of the type RCOXJN=I \ = can be plausibly attributed13 to the change in double bond character of the C=O group in the latter case where the electron pair on S1 is coni- mitted to the electron system of the heterocyclic ring.

We had assumed that our IY-methylpyrazoles had the structures shown, rather than the possible alterna- tive system V for reasons which have since been ad- vanced by Clinton, et a1.,6 when considering the case of steroidal [3,2-c]pyrazoles. The disclosure6 by these

MeOH

( 5 ) N o s~ectroscopic da ta were reported for compounds IIa-d by the Italian workers2 and we show these figures in Table 11, together with melting points (corrected) and optical rotations measured in solvents diffrring from those in ref. 2.

(6) R. 0. Clinton, 4. J. Manson. F. TV. Stonner, H. C. Neumann. R. G. Christiansen. R. L. Clarke, J. H. Ackerman, D. F. Page, J. W. Dean, W. 12. Dickinson. and C. Carabateas, J . Am. Chem. Soc., 83, 1478 ( l k 6 1 ) . (7) R. Huttel and J. Kratzer, Ber. , 92, 2014 (1959). (8 ) H. A . Staab, Ann., 622, 31 (1959). (9) After this work was completed, a publication appeared [K. Bruckner,

K. Irmscher, F. Werder, K. H. Bark, and H. N e t z , Ber., 94, 2897 (1961j1 in which the preparation of compound IVa was reported. The ghysiral con- s tan ts recorded for IVa b y these workers are in good agreement with those which we observed.

(10) Huttel and Kratzerr report A::? 251 m r (14,160) for N-acetyl-4- ethylpyrazole, compared with X d , ' , " p 218 mp ( e 3,450) for the parent 4- ethylpyrszole.

(11) L. J. Bellamy, "The Infrared Spectra of Complex Molecules," Methuen, London, 2nd Ed., 1958, p. 205.

(12) J. Elks and G. H. Phillipps, J . Chem. Soc., 4326 (1956), describe the infrared spectra of some steroidal acetylhydraeones and of acetone acetyl- hydrazone (A,% 1668 cm.-*: 6.00 p ) .

(13) W. Ried and F. .J . Konigstein, Ann., 626, 53 (1959).

T $14

H \7

VI VI1

In tlic case of the X-acetyl [li,lG-c]pyrazole systmi, we propose the structure VIIT, rather thaii the stltPriin- t i w struetiire IX.

/NCOCHs N /NCOCHs N

' H ' H VI11 IX

'I'hc ii.111.r. spectra of the pyrazoles indicate that the ( ' - 1 8 mctliyl iwoiiaiicc is shifted wlativc.ly littlr on

TAI31,I: TI

N.\r 11. 1)ATA I O R [17,1&0] 1'1RAZOLES'

N--NR2

C-IS n' It 2

R'O &AH

1j ' 1( 2 tnethhl

CHl I1 1 os 3.84 CII, CHJ 1 00 3 84 3.81 CH,CO CHI 1 00 2 27 3 83 CHJC'O CH,CO 1 OY 2 30 2 0s CIII II.HC1 I 24

ti S.m.r . spectra ae re meosurcd in CL)C'12 solution, at GO 1 1 ~ , \+it11 tetraiiiethylsilane as internal reference, using a J7ilrian A - G O spectronietcr. I'ositioiis of niethx 1 resonances are given in pairt- per inillion (p p 111 ), tetrarneth? lsilane = 0. We thank Ih. T,t.iitl

,\.landell, r: it I ory 1-niversit r, .It l:mt:L, U eorgia, for f hese niei is i I i t'-

Experimental

nic,nts. analytical Laboratory, Fchering Coqiorci t,ion).

N-Alkylation and N-Acylation of 1,3,5( lO)-Estratrieno[l7, 16-c]pyrazoles. (a) [17,16-c]N-Methylpyrazoles. 3-Methoxy- 1,3,5( lO)-estratrieno[17,16-c]N-methylpyrazole (IId) from 3- Hydroxy-1,3,5(10)-estratrieno[l7,16-c]pyrazole (IIa).-To a stirred refluxing solution of 3-hydroxy-1,3,5( 10)-estratrieno [ 17,- 16-clpyrazole (IIa, 1 g.) and potassium hydroxide (6 g.) in meth- :mol (50 ml.) and Tyater (10 ml.), was added dimethyl sulfate (1.0 id . ) . After 30 min. another 1.0-ml. portion of dimethyl sulfate \vas added, and this operat'ion was repeated twice more a t 30 min. intervals (total volume of dimethyl sulfate used was 4 nil., total reaction time was 2 hr. under reflux). The reaction mixture was then concentrated to low volume, diluted with ivater, and left a t room temperature overnight. The mixture \vas then ext,racted ni th methylene chloride, and the extract \vas washed with water and evaporated in vamo. The solid residue was crystallized from aqueous methanol to give I Id (740 mg.), identical in all respects with the compound obtained by the action of niethylhydrazine on 16-hydroxymethylene estrone 3- methyl ether.

Similarly, 3-methoxy-1,3,5( lO)-estratrieno[ 17,16-c]pyrazole ( I Ic) was S-methylated to IId, usingt he same procedure (dimethyl sulfate-potassium hydroxide).

(b) 1,3,5( l0j-Estratrieno[ 17,16-c] N-acety1pyrazoles.-A solu- tion of the steroidal [17,16-c]pyrazole (1.0 g.) in acetic anhydride (ti ml.) was heated a t 95" for 3 hr. On cooling, the [17,16-c]- X-acetylpyrazole crystallized out, and was filtered off, dried, and recrystal!ized from acetone-hexane.

3p-Hydroxy-5-androsteno[17,16-c] pyrazole (IVa).-This com- pound was prepared from 16-hydroxymethylene-3p-hydroxy-5- sndrosten-17-one (10 g.) and hydrazine (10 g; 955x) in refluxing ethanol (300 ml.) fur 3 hr. by the procedure outlined in b. The pure product (6.8 g.) had m.p. 256-259' de^.^: [ a ] ~ -58,

mp(6,300); X:ir13.15, 6.00, 6.14, and6.3Zp. Anal. Calcd. for CIOH2J20: C, 72.69; H, 9.15; S, 8.48.

Found: C, 72.98; H, 9.17; S, 8.48. 30-Acetoxy-5-androsteno [ 17,16-c] N-acetylpyrazole (IVb1.-

A solution of the foregoing pyrazole (IVa, I g.) in acetic anhydride (3.0 ml.) was heated a t 95" for 1.5 hr. Evaporation to dryness gave a solid residue which was crystallized from aqueous methanol to furnish the pure X-acetylpyrazole (IVb, 880 mg.), m.p. 198- L ' O O O , [e111 -60", A:::" 255 mp ( E 20,500); A:!:' 5.75, 6.24, 6.62, :LIld 8.00 p.

Anal. Calcd. for C24H~2S208 : C, 72.69; H, 8.13; ?;, 7.07. Found: C, 72.93; H, S.38; S, 7.35.

30-Hydroxy-5-androsteno [ 17,16-c] pyrazolium Chloride (IVa. HCI). (a).-To a solution of 3p-hydrouy-5-androsteno[l7,16-c]- pyrazole ( IVa, 100 mg.) in methanol (15 ml.) was added concen- trated hydrochloric arid (1.0 nil.), and the solution Ras left a t rooni temperature overnight. Dilution n-ith water and filtration gave the hydrochloride salt of IVa which was crystallized from aqueous methanol, t o give material of m.p. 190-200" dec., A",': 3.05,3.85,5.3,6.38,and6.55p.

-1nal. Calcd. for C2,H,,C1H20: C, 68.84; H, 8.38; N, 8.03; C1, 10.16.

( b ) A solution of the [17,16-c]pyrazole (IVa, 200 mg.) in ether (15 nil.) and dioxane (30 ml.) was stirred while a brisk stream of hydrogen chloride gas was bubbled through the solution. The precipitated hydrochloride salt was filtered, washed with ether, and dried to give material identical (m.p., m.m.p., infrared), ivith the compound prepared in a.

3-Methoxy 1,3,5( 10)-Estratrieno[ 17,16-c]pyrazolium Chlo- ride.-Dry HC1 gas n-as bubbled through an ethereal solution (150 nil.) of 3-methoxy 1,3,5( lO)-estratrieno[17,16-c]pyrazole (IIc, 1 g.) until a n-hite precipitate formed. The mixture was filtered, and the solid was washed with ether and then crystallized twice from methanol to give the pyrazolium chloride (IIc .HCI, 200 mg.), n1.p. 232-235", A2:;'3.88, 6.22, 6.38, and6.7p.

Anal. Calcd. for C2oH3;CIK20: C, 69.65; H, 7.31; ?J, 8.12; C1,10.28. Found: C, 69.43; H, 7.34; X, 8.38; C1, 10.48.

3-Hydroxy 1,3,5(10)-Estratrieno[l7,16-c]pyrazolium Chlo- ride.-A solution of 3-hydroxy 1,3,5( lO)-estratrieno[17,16-c]- pyrazole ( I Ia , 600 mg.) in methanol (90 ml.) containing concen- trated H C l ( 6 ml.) was left a t room temperature for 48 hr. Dilu- tion with water gave a precipitate which was filtered, washed with vxter, and dried. Crystallization from methanol-water gave the pyrazolium chloride (IIa.HC1, 400 mg.), m.p. 303-309" dec.; A:>:::' 2.95, 3.1S, 3.7, 5.3,6.2,6.35, 6.45, and 6.7 p.

-lrtal. Calcd. for C1YH?3C1?;20: C, 88.97; H, 7.01; N, 8.47; ('1, 10.72.

Found: C, 68.37; H, 8.00; ?;, 7.81; C1, 10.17.

Found: C, 6S.64; H, 7.3s; S, 8.31; CI, 10.99.

Ariesthetic Steroid Uerivatives

H. I). BROWN AND L. H . SAREII

IlfercX: Sharp & Dohme Research Laboratories, ULcioLoti ot Merck & Co., Inc. , Rahway, Sew Jersey

fiecezoed June 24, 1963

In coiiiiectiori with a study of water soluble deriva- tives of the anesthetic steroids, pregnaii-3a-ol-20-oiie and pregnaii-3cr-ol-3,20-dione, a number of functional derivatives were prepared which could revert to the parent compound in vivo. TWO of the more interesting compounds in this series are described. The 3-phos- phate ester of pregnan-3a-ol-20-one could coiiceivably be hydrolyzed to the parent sterol in uiuo, since phos- phate esters of 21-oxy steroids are known to possess the antiinflammatory activity of the parent steroid.2 Like- wise, 21-carboxypregiian-3cr-ol-3,20-dione was prepared in the hope that the solubilizing carboxy group would be removed in oivo following intravenous administration of the sodium salt.

The phosphate ester of pregnanolone was prepared by addition of pregnanolone to phosphorus oxychloride to produce the dichlorophosphate. This in turn was hydrolyzed in dilute acid to the dihydrogeii phosphate ester which fortunately could be separated by extrac- tion from phosphoric acid.

The 21-carboxy derivative of 11-ketopregiianolone was obtained via the oxalyl derivative, isolated as the eiiolate followiiig condensation of dimethyl oxalate with the steroid in the presence of dry sodium methoxide. Hydrogen peroxide cleavage of the keto ester gave the desired 21-carboxylic acid. The acid slowly lost carbon dioxide at room temperature and a t the melting point was completely converted into 11-ketopregnanoloiie.

Intravenous administration of the 3-phosphate ester of pregnanolone to dogs at a dose of 10 mg./kg. pro- duced no anesthesia. Similarly, administration of the freshly prepared sodium salt of 21-carboxy-11-keto pregnanolone a t a dose of 10 mg.,'kg. (ll-ketopreg- iianolone equivalent) resulted only in a transient seda- tioii with no measurable ane~thes ia .~

Experimental4

21-Oxalylpregnan-3a-ol-ll,20-dione.-Sodium methoxide (2 N , 11 ml.) in methanol was added to 25 ml. of dry benzene and the solvent was removed in vacuo. Additional solvent was added followed by a second concentration and, finally, baking on a steam bath under vacuum. To the dry fluffy powder, 2.36 g. (0.02 mole) of freshly distilled dimethyl oxalate was added a t room tempera- ture. The mixture was heated with stirring to reflux and cooled, and then 3.32 g. (0.01 mole) of 11-ketopregnanolone in about 25 ml. of benzene was added portionwise a t room temperature. -4lmost immediately a yellow gum precipitated. The reaction mixture was stirred for 2 hr. and then decanted, and the gum was washed with ether by decantation. Following drying in vacuo,

(1) For selected references on steroid anesthetics see: (a) H. Selye, Proc. Soc. Ezptl. Bid. M e d . , 46, 116 (1941) ; (b) S . K. Figdor, &I. J. Rodet, B. RI. Bloom, E. G. Agnello, S. K. P'an, and G. D. Laubach, J . Pharmacal. Ezptl. Therap., 119, 229 (1957) .

(2) (a) G. I. Poos, R. Hirschmann, G. A . Bailey, F. Cutler, Jr., L. H. Sarett , and J. hl. Chemerda, Chem. Ind. (London), 12FO (1958); J. C. Melhyand R. H. Silber, A m . Practitioner Dig. Treat., 12, 156 (1901).

(3) The authors are indebted to Dr. L. S. Watson of our Biological Re- search Laboratories for these results.

(4) Melting points were taken on a liofler micro hot stage. The authorti are indebted to D r . N. R. Trenner and hIr. R. Walker for the infrared sueotra and to hIr. R. Boos for the microanalyses.

(b)