FIELD OF THE INVENTION
[0001] The present invention relates generally to the field of steroids and, in particular,
to novel 17-α-substituted, 11-β-substituted-4-aryl and 21-substituted 19-norpregnadienedione
analogs which possess potent antiprogestational activity with minimal antiglucocorticoid
activity.
BACKGROUND OF THE INVENTION
[0002] There have been numerous attempts over the past few decades to prepare steroids with
antibormonal activity. These have been reasonably successful where antiestrogens and
antiandrogens are concerned. However, the discovery of effective antiprogestational
and antiglucocorticoid steroids has proved to be a formidable task for the steroid
chemist. It has been generally recognized for some years, however, that antiprogestational
steroids would find wide applicability in population control, while antiglucocorticoids
would be extremely valuable in the treatment of, for example, Cushing's syndrome and
other conditions characterized by excessive endogenous production of cortisone. In
the last decade, largely through the efforts of Teutsch,
et al. of the Roussel-Uclaf group in France, a new series of 19-nortestosterone derivatives
has been synthesized with strong affinity for the progesterone and glucocorticoid
receptors and with marked antiprogestational and antiglucocorticoid activity
in vivo.
WO-A-89/12448 discloses anti-progestational and anti-glucocorticoid compounds which are 11.beta.-phenyl
19-norpregn-4,9-dien-3,20-dione derivatives. This important discovery revealed the
existence of a pocket in the progesterone/glucocorticoid receptors that is able to
accommodate a large 11β-substituent on selected 19-nortestosterone derivatives. By
suitable selection of such a substituent, steroids with antihormonal properties were
obtained.
[0003] The pioneering studies of Teutsch,
et al. on the synthesis of antiprogestational and antiglucocorticoid steroids is summarized
in a recent review article (
G. Teutsch in Adrenal Steroid Antagonism. Ed. M. K. Agarwal, Walter de Gruyter and
Co., Berlin, 1984. pp. 43-75) describing the work leading to the discovery of RU-38,486, the first steroid of
this type selected for clinical development. RU-38,486 or mifepristone was found to
be an effective antiprogestational/contragestative agent when administered during
the early stages of pregnancy (IPPF Medical Bulletin 20; No. 5, 1986). In addition
to these antiprogestational properties, mifepristone has very significant antiglucocorticoid
activity and was successfully used by
Nieman, et al., J. Clin, Endocrinology Metab., 61:536, (1985)) in the treatment of Cushing's syndrome. In common with the vast majority of steroidal
hormone analogs, mifepristone additionally exhibits a range of biological properties.
Thus, for example, it exhibits growth-inhibitory properties towards estrogen-insensitive
T47Dco human breast cancer cells (
Horwitz, Endocrinology, 116:2236, 1985). Experimental evidence suggests that the metabolic products derived from mifepristone
contribute to its antiprogestational and antiglucocorticoid properties (
Heikinheimo, et al., J. Steroid Biochem., 26:279 (1987)).
[0004] Ideally, for purposes of contraception, it would be advantageous to have compounds
which possess antiprogestational activity without (or with minimal) antiglucocorticoid
activity. Although there have been a number of attempts to modify the mifepristone
structure in order to obtain separation of the antiprogestational activity from the
antiglucocorticoid activity, this goal has not yet been fully achieved. As such, there
remains a need in the art for the development of new steroids which possess antiprogestational
activity with minimal antiglucocorticoid activity.
SUMMARY OF THE INVENTION
[0005] The present invention provides new steroids which possess potent antiprogestational
activity with minimal antiglucocorticoid activity.
[0006] More particularly, the present invention provides compounds 65, 104b, 105b, 105c,
106b, 106c, 113d, 122b and 123b as disclosed in the examples and figures 4 and 7-9
and as specified in the claims. Further compounds are also disclosed herein, including
compounds 73 and 112d.
[0007] As explained above, the compounds of the present invention possess potent antiprogestational
activity with minimal antiglucocorticoid activity and, thus, they are suitable for
long term use in the treatment of human endocrinologies or other conditions in steroid-sensitive
tissues. Specific conditions for treatment include, but are not limited to, endometriosis
(
Kettel, L.M., et al., Fertil Steril, 56:402-407;
Murphy, A.A., et al., Fertil Steril, 6:3761-766;
Grow, D.R, et al., J. Clin. Endocrinol. Metab., 81:1933-1939:) uterine leiomyoma (Murphy, A.A.,
et al., Ibid.; Murphy, A.A., et al., J. Clin. Endocrinol. Metab., 76:513-517), uterine fibroid (
Brogden, R.N., et al., Drugs, 45:384-409), meningioma (Brogden, RN.,
et al., Ibid.;
Poisson, M., et al., J. Neurooncol., 1:179-189;
Carroll, R.S., et al., Cancer Res., 53:1312-1316;
Mahajan, D.K. and London, S.N., Fertil Steril, 68:967-976 (1997)), and metastatic breast cancer (Brogden, R.N.,
et al., Id.;
Rochefort, H., Trends in Pharmacol. Sci., 8:126-128;
Horwitz, K.B., Endocr. Rev., 13:146-163 (1992) Mahajan, D.K. and London. S.N.,
Id.). Other uses include, but are not limited to, contraception (
Wood, A.J.J., N. engl. J. Med., 329:404-412 (1993);
Ulmann, A., et al., Sci. Amer., 262:42-48 (1990)), emergency postcoital contraceptive (
Reel, J.R., et al., Contraception, 58:129-136 (1998)) and inducement of cervical ripening.
[0008] As such, in addition to providing the above mentioned compounds, the present invention
provides these compounds for use in methods wherein the compounds are advantageously
used,
inter alia, to antagonize endogenous progesterone; to induce menses; to treat endometriosis;
to treat dysmenorrhea; to treat endocrine hormone-dependent tumors (
e.g., breast cancer, uterine leiomyomas,
etc.); to treat meningiomas; to treat uterine fibroids; to inhibit uterine endometrial
proliferation; to induce cervical ripening; to induce labor; and for contraception.
[0009] Other features, objects and advantages of the invention and its preferred embodiments
will become apparent from the detailed description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figures 1 through
11 illustrate the synthetic schemes used to prepare the compounds of the invention and
related compounds not forming part of the present invention.
DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS
[0011] The compounds of the present invention can readily be synthesized in a variety of
ways using modern synthetic organic chemistry techniques. Typically, the compounds
of the present invention are prepared using the synthetic schemes set forth in Figures
4 and 7-9. In general, there are five strategic steps that are useful in the synthesis
of the antiprogestational agents of the present invention. They are: (1) C21-substitution;
(2) construction of the 17α-hydroxy-20-ketone pregnane side chain with the natural
configuration via the SNAP reaction; (3) modification of the 17α-hydroxy moiety; (4)
regiospecific synthesis of the epoxide and 1,4-conjugate grignard addition of a variety
of 4-substituted aryl compounds; and (5) deketalization at C3 and 20 and concomitant
dehydratration at C5. Each of these five strategic steps is described in greater detail
hereinbelow. Moreover, a more detailed description of the synthetic protocols used
to prepare the compounds of the present invention is set forth in the Example Section.
It will be readily apparent to those of skill in the art that the particular steps,
or combination of steps, used will vary depending on the compound being synthesized.
Some parts of the following description of the synthetic techniques, some of the examples
and figures 1-3, 5, 6, 10 and 11 relate to the synthesis of related compounds other
than those of the present invention, but which nonetheless illustrate synthetic techniques
relevant to the synthesis of the compounds of the present invention.
[0012] Synthesis of the 17α,21-dimethoxy derivative (
113d) was achieved via oxidation at C-21 to afford the 21-hydroxy derivative (
107) of the 17a-methoxy compound (
94) following a modification of the procedure reported by
Moriarty, R.M. et al., J. Chem. Soc. chem. Commun., 641-642 (1981),
and Velerio, et al., Steroids, 60:268-271 (1995). Subsequent O-methylation provided the key 17α,21-dimethoxy intermediate (
108) (
see, Figure 8). Reduction of the 20-ketone
(108) to the 20ξ-ol
(109) followed by epoxidation at C5 and C10, copper (I) catalyzed conjugate Grignard addition
to the 5α, 10α-epoxide (
110), selective oxidation of the secondary alcohol, 20ξ-ol (
111) using IBX to the 20-ketone (
112), hydrolysis and acetylation, led to the target 17α,21-dimethoxy derivative (
113d).
2. Silicon Nucleophilic Annelation Process (SNAP)
[0013] As described herein silylation of β-cyanohydrin ketal with halomethyldimethylsilyl
chloride afforded the chloro- or broroomethyl dimethylsilyl ether. The reductive SNAP
reaction provided the 17α-hydroxy-20-ketopregnane side chain with the natural configuration
at C17 (
Livingston, D.A., et al., J. Am. Chem. Soc., 112:6449-6450 (1990);
Livingston, D.A., Adv.Med. Chem., 1:137-174 (1992);
U.S. Patent No. 4,092,693, which issued to
Livingston, D.A., et al. (May 1, 1990); U.S. Patent No. 4,977,255, which issued to Livingston, D.A., et al. (December 11, 1990). Alternatively, the
formation of the halomethyldimethylsilyl ether, followed by treatment with lithium
diisopropyl amide, provided the 21-substituted -17α-hydroxy-20-ketopregnanes,
3. 17α-Substitution
[0014] All 17α-esters illustrated in Figures 4-11 were prepared from their 17α-hydroxy precursors.
With the exception of the 17α-formate (
69A) and the 17a,21-diformate
(139), all 17α-esters were also obtained via a mixed anhydride procedure (
Carruthers, N.I. et al., J. Org. Chem., 57:961-965 (1992)).
[0015] 17α-methoxy steroid (
93) became available in large quantities from the 17α-hydroxydienedione (
92) leading to a new series of antiprogestational agents, such as compounds
97 and
113d. Methylation of 17α-hydroxy group was most efficiently carried out using methyl iodide
and silver oxide with acetonitrile as a cosolvent as described in the general procedure
of
Finch, et al. (J. Org. Chem., 40:206-215 (1975)). Other syntheses of 17α-methoxy steroids have been reported in the literature (
see, e.g., Numazawa, M. and Nagaoka, M., J. Chem. Soc. Commun., 127-128 (1983);
Numazawa, M. and Nagaoka, M., J. Org. Chem., 50:81-84 (1985);
Glazier, E.R., J. Org. Chem., 27:4397-4393 (1962).
4. 11β-Aryl-4-Substitution
[0016] The introduction of a variety of 4-substituted phenyl group at C11β into 19-norprogesterone
requires the 5α,10α-epoxide. Epoxidation of
2, 23, 34, 42, 50, 88, 94, 99, 109 and
119 has been known to be problematic (
see, Wiechert, R. and Neef, G., J. Steroid Biochem., 27:851-858 (1987)). The procedure developed by
Teutsch, G., et al. (Adrenal Steroid Antagonism (Agarwal, M.K., ed.), 43-75, Walter
de Gruyter & Co., Berlin, N.Y. (1984)),
i.e., H
2O
2 and hexachloro or fluoroacetone, proved to be regioselective, but not highly stereoselective.
A mixture of 5α,10α-epoxide and the corresponding 5β,10β-isomer was formed in approximately
a 3:1 ratio. However, reduction of the C20-ketone (
108) to the C20-ol (
109) prior to opoxidation, resulted in a 9:1 ratio of the desired 5α,10α-epoxide.
[0017] Treatment of the 5α,10α-epoxides with 3-5 equivalents of Grignard reagents prepared
from various 4-substituted aryl bromides
(see, Yux'ev, Y.K., et al,, Izvest. Akad. Nauk. S.S.S.R., Otdel Khim Nauk, 166-171 (CA 45:
10236f, (1951));
Wolfe, J.P. and Buchwald, S.L., J. Org. Chem., 62:6066-6068 (1997);
Veradro, G., et al., Synthesis, 447-450 (1991);
Jones, D.H., J. Chem. Soc. (C), 132-137 (1971);
Detty et al., J. Am. Chem. Soc., 105:875-882 (1983), and
Rao, P.N. et al., Steroids, 63:523-550 (1998)) in the presence of copper (1) chloride as a catalyst provided the desired 11β-4-substituted
phenyl steroids. It is noted that 4-bromothioanisole was purchased from the Aldrich
Chemical Co. (Milwaukee, Wisconsin). Evidence of the 11β-orientation of the 4-substituted
phenyl substituent was shown by the upfiled shift of the C18 methyl group (δ = 0.273-0.484
ppm in CDCl
3), which is in agreement with Teutsch's observations (
see, Teutsch, G. and Belanger, A., Tetrahedron Lett., 2051-2054 (1979)).
[0018] The presence of an unprotected 20-ketone resulted in low yields or in undesirable
Grignard product mixtures. This was circumvented by reduction of the 20-ketone (analysis
of this material by NMR indicated a single isomer; no further work was done for identification
of this single isomer) prior to epoxidation and subsequent oxidation of the 20-alcohol
by use of iodoxybenzoic acid (IBX) (
Dess, D.B. and Martin, J.C., J. Org. Chem., 48:4155-4156 (1983);
Frigerio, M. and Santagostino, M., Tetrahedron Letters, 35:8019-8022 (1994); and
Frigerio, M, et al., J. Org. Chem., 60:7272-7276) after Grignard addition (
see, Figure 8).
5. Deketalization
Deketalization with concomitant dehydration at C-5 in acidic media proceeded smoothly
to provide the 4,9-dione-3,20-dione.
[0019] Quite surprisingly, the compounds of the invention possess potent antiprogestational
activity with minimal antigincocorticoid activity. As a result of their antiprogestational
activity, the compounds of the invention can advantageously be used,
inter alia, to antagonize endogenous progesterone; to induce menses; to treat endometriosis;
to treat dysmenorrhea; to treat endocrine hormone-dependent tumors; to treat meningioma;
to treat uterine leiomyonas, to treat uterine fibroids; to inhibit uterine endometrial
proliferation; to induce labor; to induce cervical ripening, for hormone therapy;
and for contraception.
[0020] More particularly, compounds having antiprogestational activity are characterized
by antagonizing the effects of progesterone. As such, the compounds of the present
invention are of particular value in the control of hormonal irregularities in the
menstrual cycle, for controlling endometriosis and dysmenonhea, and for inducing menses.
In addition, the compounds of the present invention can be used as a method of providing
hormone therapy either alone or in combination with astrogenic substances in postmenopausal
women, or in women whose ovarian hormone production is otherwise compromised.
[0021] Moreover, the compounds of the present invention can be used for control of fertility
during the whole of the reproductive cycle. For long-term contraception, the compounds
of the present invention can be administered either continuously or periodically depending
on the dose. In addition, the compounds of the present invention are of particular
value as postcoital contraceptives, for rendering the uterus inimical to implantation,
and as "once a month" contraceptive agents.
[0022] A further important utility for the compounds of the present invention lies in their
ability to slow down growth of hormone-dependent tumors and/or tumors present in hormone-responsive
tissues. Such tumors include, but are not limited to, kidney, breast, endometrial,
ovarian, and prostate tumors,
e.g., cancers, which are characterized by possessing progesterone receptors and can be
expected to respond to the compounds of this invention. In addition, such tumors include
meningiomas. Other utilities of the compounds of the present invention include the
treatment of fibrocystic disease of the breast and uterine.
[0023] Compounds suitable for use in the above method of the present invention can readily
be identified using
in vitro and
in vivo screening assays known to and used by those of skill in the art. For instance, a
given compound can readily be screened for its antiprogestational properties using,
for example, the anti-McGinty test and/or the anti-Clauberg test described in the
examples. In addition, a given compound can readily be screened for its ability to
bind to the progesterone and/or glucocorticoid receptors or to inhibit ovulation using
the assays described in the examples. Moreover, a given compound can readily be screened
for its ability to inhibit tumor cell growth (
e.g., malignant tumor growth,
i.e., cancer) or to abolish tumorigenicity of malignant cells
in vitro or
in vivo. For instance, tumor cell lines can be exposed to varying concentrations of a compound
of interest, and the viability of the cells can be measured at set time points using,
for example, the alamar Blue® assay (commercially available from BioSource, International
of Camarillo, California). Other assays known to and used by those of skill in the
art can be employed to identify compounds useful in the methods of the present invention.
[0024] The compounds according to the present invention can be administered to any warm-blooded
mammal such as humans, domestic pets, and farm animals. Domestic pets include dogs,
cats,
etc. Farm animals include cows, horses, pigs, sheep goats,
etc.
[0025] The amount of active ingredient that can be combined with a carrier material to produce
a single dosage form will vary depending upon the disease treated, the mammalian species,
and the particular mode of administration. For example, a unit dose of the steroid
can preferably contain between 0.1 milligram and 1 gram of the active ingredient.
A more preferred unit dose is between 0.001 and 0.5 grams. It will be understood,
however, that the specific dose level for any particular patient will depend on a
variety of factors including the activity of the specific compound employed; the age,
body weight, general health, sex and diet of the individual being treated; the time
and route of administration; the rate of excretion; other drugs which have previously
been administered; and the severity of the particular disease undergoing therapy,
as is well understood by those of skill in the area.
[0026] The compounds of the present invention can be administered by a variety of methods.
Thus, those products of the invention that are active by the oral route can be administered
in solutions, suspensions, emulsions, tablets, including sublingual and intrabuccal
tablets, soft gelatin capsules, including solutions used in soft gelatin capsules,
aqueous or oil suspensions, emulsions, pills, lozenges, troches, tablets, syrups or
elixirs and the like. Products of the invention active on parenteral administration
can be administered by depot injection, implants including Silastic TM and biodegradable
implants, intramuscular and intravenous injections.
[0027] Compositions can be prepared according to any method known to the art for the manufacture
of pharmaceutical compositions and such compositions can contain one or more agents
selected from the group consisting of sweetening agents, flavoring agents, coloring
agents and preserving agents. Tablets containing the active ingredient in admixture
with nontoxic pharmaceutically acceptable excipients which are suitable for manufacture
of tablets are acceptable. These excipients can be, for example, inert diluents, such
as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate,
granulating and disintegrating agents, such as maize starch, or alginic acid; binding
agents, such as starch, gelatin or acacia; and lubricating agents, such as magnesium
stearate, stearic acid and talc. Tablets can be uncoated or, alternatively, they can
be coated by known methods to delay disintegration and adsorption in the gastrointestinal
tract and thereby provide a sustained action over a longer period. For example, a
time delay such as glyceryl monostearate or glyceryl distearate alone or with a wax
can be employed.
[0028] Formulations for oral use can also be presented as hard gelatin capsules wherein
the active ingredient is mixed with an inert solid diluent, for example calcium carbonate,
calcium phosphate or kaolin, or as soft gelatin capsules wherein the active ingredient
is mixed with water or an oil medium, such as peanut oil, liquid paraffin or olive
oil.
[0029] Aqueous suspensions of the invention contain the active materials in admixture with
excipients suitable for the manufacture of aqueous suspensions. Such excipients include
a suspending agent, such as sodium carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose,
sodium alginate, polyvinylpyrolidone, gum tragacanth and gum acacia, and dispersing
or wetting agents such as a naturally occurring phosphatide (
e.g., lecithin), a condensation product of an alkylene oxide with a fatty acid (
e.g., polyoxyethylene stearate), a condensation product of ethylene oxide with a long chain
aliphatic alcohol (
e.g., heptadecaethylene oxycetanol), a condensation product of ethylene oxide with a partial
ester derived from a fatty acid and a hexitol (
e.g., polyoxyethylene sorbitol mono-oleate), or a condensation product of ethylene oxide
with a partial ester derived from fatty acid and a hexitol anhydride (
e.g., polyoxyethylene sorbitan monooleate). The aqueous suspension can also contain one
or more preservatives such as ethyl or n-propyl p-hydroxybenzoate, one or more coloring
agents, one or more flavoring agents and one or more sweetening agents, such as sucrose,
aspartame or saccharin. Ophthalmic formulations, as is known in the art, will be adjusted
for osmolarity.
[0030] Oil suspensions can be formulated by suspending the active ingredient in a vegetable
oil, such as arachis oil, olive oil, sesame oil or coconut oil, or in a mineral oil
such as liquid paraffin. The oil suspensions can contain a thickening agent, such
as beeswax, hard paraffin or cetyl alcohol. Sweetening agents can be added to provide
a palatable oral preparation. These compositions can be preserved by the addition
of an antioxidant such as ascorbic acid.
[0031] Dispersible powders and granules of the invention suitable for preparation of an
aqueous suspension by the addition of water can be formulated from the active ingredients
in admixture with a dispersing, suspending and/or wetting agent, and one or more preservatives.
Suitable dispersing or wetting agents and suspending agents are exemplified by those
disclosed above. Additional excipients, for example sweetening, flavoring and coloring
agents, can also be present.
[0032] The pharmaceutical compositions of the invention can also be in the form of oil-in-water
emulsions. The oily phase can be a vegetable oil, such as olive oil or arachis oil,
a mineral oil, such as liquid paraffin, or a mixture of these. Suitable emulsifying
agents include naturally-occurring gums, such as gum acacia and gum tragacanth, naturally
occurring phosphatides, such as soybean lecithin, esters or partial esters derived
from fatty acids and hexitol anhydrides, such as sorbitan monooleate, and condensation
products of these partial esters with ethylene oxide, such as polyoxyethylene sorbitan
monooleate. The emulsion can also contain sweetening and flavoring agents.
[0033] Syrups and elixirs can be formulated with sweetening agents, such as glycerol, sorbitol
or sucrose. Such formulations can also contain a demulcent, a preservative, a flavoring
or a coloring agent
[0034] The pharmaceutical compositions of the invention can be in the form of a sterile
injectable preparation, such as a sterile injectable aqueous or oleaginous suspension.
This suspension can be formulated according to the known art using those suitable
dispersing or wetting agents and suspending agents which have been mentioned above.
The sterile injectable preparation can also be a sterile injectable solution or suspension
in a nontoxic parenterally-acceptable diluent or solvent, such as a solution of 1,3-butanediol.
Among the acceptable vehicles and solvents that can be employed are water and Ringer's
solution, an isotonic sodium chloride. In addition, sterile fixed oils can conventionally
be employed as a solvent or suspending medium. For this purpose any bland fixed oil
can be employed including synthetic mono- or diglycerides. In addition, fatty acids
such as oleic acid can likewise be used in the preparation of injectables.
[0035] The compounds of this invention can also be administered in the form of suppositories
for rectal administration of the drug. These compositions can be prepared by mixing
the drug with a suitable non-irritating excipient which is solid at ordinary temperatures
but liquid at the rectal temperatures and will therefore melt in the rectum to release
the drug. Such materials are cocoa butter and polyethylene glycols.
[0036] They can also be administered by in intranasal, intraocular, intravaginal, and intrarectal
routes including suppositories, insufflation, powders and aerosol formulations.
[0037] Products of the invention which are preferably administered by the topical route
can be administered as applicator sticks, solutions, suspensions, emulsions, gels,
creams, ointments, pastes, jellies, paints, powders, and aerosols.
[0038] The invention will be described in greater detail by way of specific examples. The
following examples are offered for illustrative purposes, and are intended neither
to limit or define the invention in any manner.
EXAMPLES
EXAMPLE 1
[0039] This example illustrates the preparation and properties of 17α-Acetoxy-11β-(4-acetylphenyl)-19-norpregna-4,9-diene-3,20-dione(
73) (
Figure 4).
Step 1. 3,20-bis-Ethylenedioxy-17α-hydroxy-19-norpregna-5(10),9(11)-diene (50):
[0040] A mixture of 17α-hydroxy-19-norpregna-4,9-diene-3,20-dione (
92,10 g, 31.8 mmol), ethylene glycol (11.10 g, 178.7 mmol), freshly distilled triethyl
orthoformate (14g, 94.1 mmol) and toluenesulfonio acid monohydrate (0.3 g, 1.58 mmol)
in CH
2Cl
2 (150 mL) was stirred at room temperature under nitrogen overnight. Analysis by TLC
(5% acetone in CH
2Cl
2) at that time indicated a complete reaction. Solid NaHCO
3 (~1 g) was added and the mixture was diluted with CH
2Cl
2 (~100 mL) and poured into H
2O. The mixture was extracted with CH
2Cl
2 (3x). The organic fractions were washed with H
2O (3x), filtered through sodium sulfate, combined and concentrated
in vacuo to give 12 g of the crude product
50 as a yellow foam. Crystallization of this crude material from CH
2Cl
2/MeOH containing a trace of pyridine gave 9.8 g of the pure diketal
50 as a light yellow solid in 77% yield; m.p. 169 - 171°C. FTIR(KBr, diffuse reflectance)
ν
max 3484 and 2912 cm
-1. NMR (300 MHz, CDCl
3): δ 0.792 (s, 3 H, C18-CH
3), 1.378 (s, 3 H, C21-CH
3), 3,816 and 4.047 (m, 4H, C20-ketal), 3.983 (s, 4H, C3-ketal) and 5.555 (m, 1 H,
C11-CH=). MS (EI) m/z (relative intensity): 402 (M
+, 100.0), 366 (2.5), 340 (20.8) 270 (59.9) and 99 (50.1).
Step 2. 3,20-bis-Ethylenedioxy-17α-hydroxy-5α,10α-epoxy-19-norpregna-9(11)-ene (51):
[0041] Hydrogen peroxide (30%, 3.3 mL, 32.31 mmol) was added to a solution of hexafluoroacetone
trihydrate (3.34 g, 16.17 mmol) in CH
2Cl
2 (53 mL) cooled to 0°C. Solid Na
2HPO
4 (1.48 g, 10.43 mmol) was added and the mixture stirred at 0°C for ½ hr. A solution
of the 3,20-diketal (
50, 6.0 g, 14.9 mmol) in CH
2Cl
2 (45 mL), precooled to 0°C, was added over a period of 10 min and the reaction mixture
was stirred overnight at 5°C. Analysis by TLC (5% acetone in CH
2Cl
2) at that point indicated absence of the starting material. The reaction mixture was
diluted with CH
2Cl
2 (~100 mL) and washed with 10% Na
2SO
3 solution (2x) and saturated NaHCO
3 solution (2x). The organic fractions were filtered through Na
2SO
4, combined and concentrated
in vacuo to give 7 g of
51 of a white foam. Trituration of the epoxide mixture (α and β) with ether afforded
3.05 g of the pure 5α,10α-epoxide
51 as a white solid in 48.9% yield; m.p. = 172-173°C. FTIR (KBr, diffuse reflectance)
ν
max 3439, 2950, 1705, 1642 and 1593 cm
-1. NMR (300 MHz, CDCl
3) δ 0.789 (s, 3 H, C18-CH
3), 1.365 (s, 3 H, C21-CH
3), 3.810 - 4.094 (m, 8 H, C3- and C20-ketals) and 6.013 (m, 1 H, C11-CH=). MS (EI)
m/z (relative intensity): 418 (M
+, 0.5), 400 (1.4), 293 (0.9), 131 (2.5), 99 (4.3) and 87 (100.00).
Step 3 3,20-bis-Ethylenedioxy-5α,17α-dihydroxy-11β-[4-(2-methyl-1,3-dioxolan-2-yl)phenyl]-19-norpregn-9-ene (56):
[0042] Magnesium turnings (435 mg, 17.9 mmol) were weighed into a 100 mL round bottom two-neck
flask equipped with a reflux condenser, a magnetic stirrer and a rubber septum. A
small crystal of iodine was added and the system was flushed with dry nitrogen and
flame dried. After the system had cooled to room temperature, freshly distilled THF
(20 mL) was introduced
via syringe followed by a small amount of dry dibromoethane (~0.1 mL). After evidence
of reaction was observed (disappearance of I
2 color, bubble formation on metal), a solution of the ketal of 4-bromoacetophenone
(
see, Detty, M.R., et al., J. Am. Chem. Soc., 105:875-882 (1983); and
Rao, P.N., et al., Steroids, 63:523-530 (1998)) (4.35 g, 17.9 mmol) in dry THF (10 mL) was added via syringe. The mixture was then
stirred in a hot water bath for 2 hr. (After 35 min, an additional 10 mL of THF was
added as a white precipitate formed and the reaction mixture thickened). The reaction
was cooled to room temperature and copper (I) chloride (177 mg, 1.79 mmol) was added
and the mixutre stirred at room temperature for ½ hr (the precipitate went back into
solution with the addition of the copper chloride). The 5α,10α-epoxide (
51, 1.5 g, 3.58 mmol) in dry THF (10 mL) was added via syringe and the reaction mixture
stirred at room temperature for 45 min. At this time, TLC (10% acetone in CH
2Cl
2) showed no starting material. Saturated NH
4Cl solution (~20 mL) was added and the mixture stirred at room temperature for ½ hr
while air was drawn through the reaction mixture to oxidize the copper. The contents
of the flask were diluted with H
2O (~100 mL) and extracted with CH
2Cl
2 (3x). The organic fractions were washed with saturated NH
4Cl solution (1x), H
2O (1x), and brine (1x), and then dried over anhydrous Na
2SO
4, filtered and concentrated
in vacuo to yield an oil. The oil was purified on a flash column (10% acetone in CH
2Cl
2) yielding 1.3 g of a stable white foam. The material was crystallized from ether
to yield 880 mg of
56 as a white crystalline solid in 42.3% yield; m.p. = 185-188°C. FTIR (KBr, diffuse
reflectance)
νmax 3501, 2940, 1609, 1443, 1371, 1181 and 1042 cm
-1. NMR (CDCl
3) δ 0.45 (s, 3 H, C18-CH
3), 1.4 (s, 3 H, CH
3 from ethylene ketal of acetophenone at C11β), 1.6 (s, 3 H, C21-CH
3), 3.6 - 4.2 (br m, 12 H, C3- and C20-ketals and ketal of acetophenone at C11β-),
4.3 (br d, 1H, C11α-CH), and 7.05 - 7.47 (dd, 4 H, aromatic-CH's). MS(EI) m/z (relative
intensity): 582 (M
+). Anal, Calcd. for C
34H
46O
8; C, 70.08; H, 7.96. Found: C, 70.00; H, 8.05.
Step 4 17α-Hydroxy-11β-(4-Acetylphenyl)-19-norpregna-4,9-diene-3,20-dione (65):
[0043] Nitrogen was bubbled through a mixture of EtOH (25 mL) and 8.5% H
2SO
4 (2:5 mL) for ½ hr to remove oxygen. The Grignard adduct (
57, 750 mg, 1.28 mmol) was added as a solid with stirring. The mixture was put into
an oil bath preheated to 95°C for 1 hr. The mixture was cooled in an ice bath and
quenched with saturated K
2CO
3 to bring the pH to ∼10. The mixture was diluted with H
2O (125 mL) and extracted with CH
2Cl
2 (3x). The organic fractions were washed with saturated NaHCO
3 (1x), H
2O (1x), brine (1x), combined and dried over anhydrous Na
2SO
4. This material was concentrated
in vacuo to give 600 mg of 65 as an oil. Tho material was purified on a flash column (10%
acetone in CH
2Cl
2) to yield 560 mg of 65. This material was crystallized from CH
2Cl
2 and ether to give 475 mg of 65 as a white solid in 85.9% yield; m.p. = foams/honeycombs
at 112-115°C. FTIR (KBr, diffuse reflectance)
νmax 3390, 2976, 1709, 1679, 1655, 1601, 1360 and 1275 cm
-1. NMR (CDCl
3) δ 0.4 (s, 3 H, C18-CH
3), 2.25(s, 3 H, C21-CH
3), 2.6 (s, 3 H, 11β-4-phenylacetyl CH
3), 3.25 (s, 1H, C17α-OH),, 4.5 (br d, 1 H, C11α-CH), 5.8 (s, 1 H, C4-CH=) and 7.2
- 8.0 (dd, 4 H, aromatic-CH's), MS (EI) m/z (relative intensity): 432(M
+, 88.7), 414 (11,3), 389 (25.4), 371 (21.1), 346(100:0), 331 (46.5), 319 (22.5), 280
(15.5), 235 (16.9), 200 (14.1), 147(18.3), 133 (18.3), 115 (12.7), 105 (15.5) and
91 (21.1)
Step 5. Preparation of the target compound 73:
[0044] The triketone (
65, 375 mg, 0.87 mmol) was dissolved in CH
2Cl
2 (10 mL) and cooled to 0°C in an ice bath. In a separate roundbottom flask, trifluoroacetic
anhydride (3.65 g, 17.3 mmol) and acetic acid (1.14 g, 17.3 mmol) were added to CH
2Cl
2 (10 mL), flushed with dry nitrogen and stirred at room temperature for ½ hr. The
mixed anhydride was then placed in an ice bath and cooled to 0°C. The cold mixed anhydride
solution was then added to the triketone
(65) solution and treated with
p-toluenesulfonic acid (152 mg, 0.79 mmol). The reaction mixture was stirred for 45
min at 0°C. The reaction was quenched with saturated K
2CO
3 (pH = 10), diluted with H
2O and extracted with CH
2Cl
2 (3x). The organic layers were combined, washed with H
2O (2x), brine (1x), dried over sodium sulfate, filtered and concentrated to yield
425 mg of crude
73. The crude product
73 was purified on a flash column (10% acetone in CH
2Cl
2) to yield 340 mg of compound
73. Crystallization from CH
2Cl
2, and ether afforded 305 mg of
73 as white solid in 73.96% yield; m.p. = 243-246°C.
[0045] Analysis by reverse phase HPLC on a Waters Nova Pak C
18 column eluted with MeOH:H
2O in the ratio of 70:30 at a flow rate of 1 mL/min and at λ = 260 nm indicated it
to be 99.6% pure. FTIR (KBr, diffuse reflectance)
vmax 2791, 1729, 1712, 1681, 1595, 1362, and 1257 cm
-1, NMR (CDCl
3) δ 0.3 (s, 3 H, C18-Me), 2.10 (s, 3 H, C17α-OAc), 2.15 (s, 3 H, C21-CH
3), 2.55 (s, 3 H, 11β-4-phenylacetyl CH
3), 4.5 (br d, 1 H, C11α-CH), 5.8 (s, 1 H, C4-CH=) and 7.2 - 8.0 (dd, 4 H, aromatic-CH's).
MS (EI) m/z (relative intensity): 474(M
+, 2.8), 414 (36.6), 399 (14.0), 389 (8.5) and 371 (100). Anal. Calcd. for C
30H
34O
5 ½Et
2O: C, 74.85; H, 7.44, Found: C, 74.94; H, 7.19.
EXAMPLE 2
[0046] This example illustrates the preparation and properties of 17α,21-Diacetoxy-11β-(4-acetylphenyl)-19-norpregna-4,9-diene-3,20-dione(
106b) (Figure 7);
Step 1. 3,3-Ethylenedioxy-17β-cyano-17α-trimethylsilyloxyesttra-5-(10),9(11)-diene
(99);
[0047] Under nitrogen, pyridine (136.9 g, 1740 mmol) solution of the cyanohydrin ketal (98,
25 g, 73.22 mmol) was treated with chlorotrimethylsilane (44g, 394 mmol). The mixture
was stirred at room temperature overnight. The reaction mixture was poured into a
50:50 mixture of ice/saturated NaHCO
3 solution (∼1.2 L), stirred until the ice had melted, and extracted with hexane (3x).
The organic extracts were washed with H
2O (3x), brine (1x), combined, dried over anhydrous Na
2SO
4, and concentrated
in vacuo. The remaining pyridine was azeotropically removed
in vacuo with heptane. Crystallisation of the residue from pentane gave 26.1 g of the pure
silyl ether (
99) as a white solid in 86.2% yield; m.p, = 99 - 101°C, FTIR (KBr, diffuse reflectance)
ν
max 2944, 2908, 2231 and 1253 cm
-1. NMR (300 MHz, CDCl
3) δ 0.229 (s, 9 H, C17α-OSi(CH
3)
3), 0.894 (s, 3 H, C18-CH
3), 3.987 (s, 4 H, 3-O
CH2CH2O) and 5.615 (t, 1 H, J = 2.55 Hz, C11-CH=). MS (EI) m/z (relative intensity): 413
(M
+, 100.0), 398 (5.5), 385 (24.0), 371 (6.4), 237 (33.9) and 69.3 (86.0).
Step 2. 3,3-Ethylenedioxy-5α-10α-epoxy-17β-cyano-17α-trimethylsilyloxyestr-9(11)-ene
(100):
[0048] Hydrogen peroxide (30%, 12 mL), 117.12 mmol) was added to a vigorously stirred mixture
of hexafluoroacetone trihydrate (20.20 g, 112.5 mmol) in CH
2Cl
2 (185 mL) cooled to 0°C in an ice bath. The reaction mixture was stirred at 0°C for
½ hr, and solid Na
2HPO
4 (11g, 77.5 mmol) was added followed by an ice-cold solution of the silyl ether (99,25
g, 60.44 mmol) in CH
2Cl
2 (185 mL). The mixture was then stirred at 0°C for 5 hr, then at 5°C overnight. Analysis
by TLC (5% acetone in CH
2Cl
2) at that time indicated a complete reaction. The reaction mixture was diluted with
CH
2Cl
2 (∼200 mL) and washed with 10% Na
2SO
3 solution (1x), H
2O (1x) and brine (1x). The organic fractions were filtered through anhydrous sodium
sulfate, combined and concentrated
in vacuo. Trituration of the residue with ether afforded 16.66 g of the pure 5α,10α-epoxide
(100) as a white solid in 64.16% yield; m.p. 156 - 160°C. FTIR (KBr, diffuse reflectance)
ν
max 2955, and 2228 cm
-1, NMR (300 MHz, CDCl
3) δ 0.219 (s, 9 H, OSi(CH
3)
3), 0.894 (s, 3 H, C18-CH
3), 3.85 - 3.97 (s, 4 H, C3-O
CH2CH2O) and 6.082 (t, 1 H, J = 2,6 Hz, C11-CH=). MS(EI) ml (relative intensity): 429 (M
+, 18.5), 401(2.8), 343 (11.1), 238 (9.5), 99 (100.0) and 86 (36.2).
Step 3. 3,3-Ethylenedioxy-5α-hydroxy-11β-[4-(2-methyl-1,3-dioxolan-2-yl)phenyl]-17β-cyano-17α-trimethylsilyloxyestr-9-ene
(101b):
[0049] Under nitrogen and in flame-dried glassware, dry THF (240 mL) was added to magnesium
turnings (2.3 g, 94.6 mmol). Solid bromoacetophenone ketal (
see, EXAMPLE 1 Step 3) (20.79 g, 85.5 mmol) was added and the mixture heated to refux.
After ½ hr of reflux, evidence of Grignard formation such as cloudiness and color
change was observed. Heating was discontinued and tho mixture stirred for 1 hr, after
which time most of the magnesium had reacted and a substantial amount of the precipitated
Grignard ragent was observed. Solid CuCl (4 g, 40.4 mmol) was added and the mixture
was stirred at room temperature for 15 min, after which time the solid reagent went
back into solution. A solution of the 5α,10α-epoxide (
100, 17.5 g, 40.73 mmol) in THF (150 mL) was added and the reaction mixture was stirred
at room temperature for 1 hr. After that time, TLC(5% acetone in CH
2Cl
2) of a small aliqout quenched with saturated NH
4Cl solution indicated a complete reaction. The reaction was quenched by the addition
of saturated NH
4Cl solution (∼50 mL). In order to oxidize Cu(I) to Cu(II), air was drawn through the
reaction mixture for ½ hr. The resulting blue mixture was diluted with ether (500
mL) and washed with H
2O (2x), brine (1x), dried over anhydrous Na
2SO
4, filtered and concentrated
in vacuo to give 41 g of the residue as an oil. Crystallization of this crude material from
ether gave the pure
101b (23.0 g) as a white solid in 95% yield; m.p. = 192 - 193°C. FTIR (KBr, diffuse reflectance):
v
max 3515, 2951, 2884, 2230, 1619, 1505 and 1102 cm
-1. NMR (CDCl
3): δ 0.25 (s, 9 H, Si(CH
3)
3), 0.5 (s, 3 H, C18-CH
3), 1.67 (s, 3 H, C11β-(acetophenone ketal CH
3), 3.67 - 4.17 (m, 8 H, C3- OCH
2CH
2O-), 4.37 (m, 2 H, C11α-CH plus OH), 7.17 (d, 2 H, J = 9 Hz, 2', 6' aromatic-CH's)
and 7.37 (d, 2 H, J = 9 Hz, 3', 5' aromatic-CH's). MS (EI) m/z (relative intensity):
593 (M
+, 3.6), 578 (6.0), 575 (9.1), 560 (2.5), 366 (5.2) 99 (27.3) and 87 (100.0). Anal.
Calcd. for C
34H
47NO
6Si: C, 68.77; H, 7.98; N, 2.36. Found: C, 68.69; H, 7.87; N, 2.43.
Step 4. 17β-cyano-17α-hydroxy-11β-(4-acetylphenyl)-estra-4,9-dien-3-one (102b);
[0050] A solution of the Grignard adduct
(101b, 23 g, 38.7 mmol) was dissolved in THF (100 mL) and the system was flushed with nitrogen.
Glacial acetic acid (314.7 g, 524 mmol) and H
2O (100 mL) were added and the mixture was stirred overnight at room temperature. At
that time, TLC (10% acetone/CH
2Cl
2) indicated an incomplete reaction. The reaction mixture was then heated to reflux
for 1 hr, after which time TLC indicated a complete reaction.
[0051] The volatiles were removed
in vacuo at 50°C and the residue diluted with H
2O (∼250 mL) and saturated NaHCO
3 solution (∼125 mL). The subsequent precipitate was extracted with EtOAc (5x) with
some difficulty in that the crude product was relatively insoluble in most solvents
used. The organic fractions were washed with H
2O (2x), brine (1x), combined, dried over anhydrous sodium sulfate, filtered and concentrated
in vacuo. Trituration of the residue with ether gave the cyanohydrin (
102b, 16.3 g) as a light yellow solid in 100% yield; m.p. = 141 - 143°C (dec), FTIR (KBr,
diffuse reflectance): v
max 3362, 2966, 2946, 2232, 1619, 1730, 1658 and 1600 cm
-1. NMR (CDCl
3 + d
6 DMSO): δ 0.57 (s, 3 H, C18-CH
3), 2.60 (s, 3 H, C11β-(4-phenyl-C(O)CH
3), 4.57 (br s, 1 H, C11α-CH), 5.80 (s, 1 H, C4-CH=), 7.40 (d, 2 H, J = 9 Hz, 2', 6'
aromatic-CH's) and 7.97 (d, 2 H, J = 9 Hz, 3', 5' aromatic-CH's), MS(EI) m/z (relative
intensity): 415 (M
+,0.5), 404 (0.4), 388 (100.0), 292 (65) and 97 (51.0). Anal. Calcd. for C
27H
29NO
3·1/3H
2O: C, 76.93; H, 7.09; N, 3.32. Found: C, 77.04; H, 6.99; N, 3.45.
Step 5. 11β-(4-acetylphenyl)-17β-cyano-17α-bromethyldimethylsilyloxyestra-4,9-dien-3-one
(103b):
[0052] Under nitrogen, a solution of the cyanohydrin
(102b, 15 g, 36.12 mmol), Et
3N (6.53 g, 64 mmol) and DMAP (2.6 g, 21.3 mmol) in dry THF (180 mL) was treated with
bromomethyldimethylsilyl chlorine (9.70 g, 54 mmol). The mixture was stirred overnight
at room temperature, diluted with ether (500 mL), filtered through Celite and
concentrated in vacuo. The relative insolubility of this material
(103b) precludes chromatographic purification useing ether as eluent. The crude material
(103b) was used directly in the subsequent reaction without further purification or characterization.
Step 6. 17α-Hydroxy-11β-(4-acetylphenyl)-21-bromo-19-norpregna-4,9-dien-3-one (104b);
[0053] Under anhydrous conditions and using a mechanical stirrer, a solution of the silyl
ether
(103b) (assumed 20.34 g, 36.12 mmol) in dry THF (500 mL) was cooled to - 78°C and treated
dropwise with a 1.5
M solution of lithium diisopropylamide (LDA) in cyclohexane (100 mL, 150 mmol). After
1 hr, the reaction mixture became very viscous, almost a gel. The reaction was quenched
at -78°C by addition of 4.45
M HBr (500 mL, 890 mmol) and the mixture allowed to warm to room temperature. After
stirring at room temperature for 1 hr, the excess acid was neutralized by slow addition
of concentrated NH
4OH solution (∼60 mL), The mixture was further diluted with H
2O (∼200 mL) and extracted with CH
2Cl
2 (3x). The organic fractions were washed with H
2O (3x), combined, filtered through Na
2SO
4 and concentrated
in vacuo to give 20 g of the residue as a foam. This material was purified
via flash chromatography eluted with (10% acetone in CH
2Cl
2) to give 2.6 g of the 21-bromo product
(104b) as a white solid in 14.1% yield. FTIR (KBr, diffuse reflectance): v
max 3340, 2946, 1723, 1693, 1679, 1645 and 1601 cm
-1. NMR (CDCl
3): δ 0.33 (s, 3 H, C18-CH
3), 2.19 (s, 3 H, 11β-(4-phenyl-C(O)CH
3), 4.30 - 4.70 (m, 3 H, C11α-CH and C21-CH
2Br), 5.83 (s, 1 H, C4-CH=), 7.33 (d, 2 H, J = 9 Hz, 2', 6' aromatic-CH's) and 7.93
(d, 2 H, J = 9 Hz, 3',5' aromatic-CH's). MS (EI) m/z (relative intensity): 512 (M
+,24.1), 466 (100), 432 (48.5), 431 (48.5), 430 (86,4), 371 (71,9) and 91 (76.0).
Step 7. 17α-Hydroxy-11β-(4-acetylphenyl)-21-acetoxy-19-norpregna-4,9-diene-3,20-dione
(105b):
[0054] A mixture of the 21-bromo drivative
(104b, 2.5 g, 4.89 mmol), anhydrous KOAc (20 g, 203.8 mmol) in dry CH
3CN (100 mL) was heated to reflux under nitrogen, After 2 hr, TLC (10% acetone in CH
2Cl
2) indicated a complete reaction. The reaction mixture was cooled to room temperature,
filtered and concentrated
in vacuo to give 2.6 g as a foam. This material was purified via flash chromatography (12%
acetone in CH
2Cl
2) followed by cyrstallization from EtOAc to give 1.5 g of the pure 17α-ol-21-acetate
(105b) as a light yellow solid in 62.6% yield; m.p. = softens at 110°C, FTIR (KBr, diffuse
reflectance): v
max 3467, 2948, 1749, 1727, 1727, 1681, 1380, 1664 and 1603 cm
-1. NMR (CDCl
3): δ 0.31 (s, 3 H, C18-CH
3), 2.15 (s, 3 H, C17α-OC(O)CH
3), 2.57 (s, 3 H, 11β-4-phenyl-C(O)C
H3), 4.5 (br d, 1 H, C11α-CH), 5.01 (dd, 2 H, J
1= 18.7 Hz, J
2 = 18 Hz, C21-
CH2OAc), 5.81 (s, 1 H, C4-CH=), 7.34 (d, 1 H, J = 8.2 Hz, 2', 6' aromatic-CH's), 7.35
(d, 1 H, J = 6.8 Hz, 2', 6' aromatic-CH's) and 7.93 (d, 2 H, J = 8.2 Hz, 3', 5' aromatic-CH's),
MS (EI) m/z (relative intensity): 490 (M
+, 88.0), 430 (100.0), 344 (80.0), 236 (44.0), and 91 (55.0). Anal, Calcd. for C
30H
34O
6'1/5CH
2Cl
2 C, 70.99; H, 6.79, Found: C, 70.83; H,
6.65.
Step 8._Preparation of the target compound 106b:
[0055] Under nitrogen trifluoroacetic anhydride (11.15 g, 53.2 mmol), glacial acetic aoid
(3025 g, 54.2 mmol) in dry CH
2Cl
2 (35 mL) were combined and stirred at room temperature for ½ hr.
p-Toluenesulfonic acid monohydrate (0.5 g, 2.63 mmol) was added and the reaction mixture
was cooled to 0°C in an ioe bath. A solution of the 17α-ol-21-acetate
(105b, 1.28 g, 2.61 mmol) in dry CH
2Cl
2 (10 mL) was precooled to 0°C and then added. The reaction mixture was stirred at
0°C. After 45 min, TLC (10% acetone in CH
2Cl
2) indicated a complete reaction. The mixture was quenched at 0°C with concentrated
NH
4OH solution (∼10 mL, ∼148 mmol), allowed to warm to room temperature, and diluted
with H
2O (∼50 mL). The pH of the aqueous fraction was adjusted to 5 with concentrated NH
4OH solution and the mixture extracted with CH
2Cl
2 (3x). The organic fractions were washed with H
2O (3x), combined, dried over anhydrous Na
2SO
4, filtered and concentrated
in vacuo to give 1.8 of the crude product as a foam. The crude material was purified via flash
chromatography (5% acetone in CH
2Cl
2) to give 1.1 g of the purified diacetate
(106b) as a foam. Crystallization of this foam from EtOAc / heptane afforded 0.78 g of the
pure solid (
106b) as a white crystalline solid in 56.1% yield.; m.p. = 197 - 199°C, Reverse phase
HPLC analysis on Phonomenex Prodigy 5 ODS-2 column eluted with H
2O/CH
3CN, 1: 1 at a flow rate of 1 mL/min and at λ = 302 nm indicated this material to be
>99% pure with a retention time (t
R) of 5.6 min. FTIR (KBr, diffuse reflectance): v
max 2951, 1757, 1678, 1664 and 1604 cm
-1. NMR (CDCl
3): δ 0.33 (s, 3 H, C18-CH
3), 2.07 (s, 3 H, C17α-OC(O)CH
3), 2.10 (s, 3 H, C21-OAc), 2.50 (s, 3 H, C11β-4-phenyl-C(O)CH
3), 4.43 (m, 1 H, C11α-CH), 4.77 (dd, 2 H, J
1= 32.9 Hz, J
2 = 14.9 Hz, C21-
CH2OAc), 5.77 (s, 1 H, C4-CH=), 7.23 (d, 2 H, J = 8 Hz, 2', 6' aromatic-CH's), and 7.83
(d, 2H, J = 8 Hz, 3', 5' aromatic-CH's). MS (EI) m/z (relative intensity): 532 (M
+, 6.2), 472 (17.3), 412 (11.3), 371 (100.0) and 91 (14.3). Anal. Calcd. for C
32H
36O
7·1/7H
2O: C, 71.81; H, 6.83. Found: C, 71.89; H, 6.87.
EXAMPLE 3
[0056] This example illustrates the preparation and properties of 17α-Acetoxy-11β-(4-acetylphenyl)-21-thioacetoxy-19-norpregna-4,9-diene-3,20-dione
(106c) (Figure 7):
Step 1. 17α-Hydroxy-11β-(4-acetylphenyl)-21-thioacetoxy-19-norpregna-4,9-diene-3,20-dione
(105c):
[0057] A mixture of the 21-bromo derivative
(104b, 5.746 g, 11.23 mmol), sodium iodide (16.84 g, 112.3 mmol), potassium thioacetate
(12.83 g, 112.3 mmol) in dry acetone (600 mL) was heated to reflux under nitrogen.
After 4 hr, TLC (50% EtOAc in hexanes) indicated a complete reaction. The reaction
was cooled to room temperature, filtered, concentrated
in vacuo, diluted with H
2O (∼200 mL) and extracted with CH
2Cl
2 (3x). The organic fractions were washed with H
2O (1x) and brine (1x), combined, dried over anhydrous sodium sulfate, concentrated
in vacuo to give the crude product as a yellow foam. This material was purified by flash chromatography
(50% EtOAc in hexanes) followed by crystallization from EtOAc/hexanes to afford the
pure 17α-ol-21-thioacetate (
105c, 3.25 g, 57.1%) as a white crystalline solid; m.p. = 159 - 160°C. FTIR (KBr, diffuse
reflectance): v
max 3325, 2950, 1723, 1688, 1637 and 1590 cm
-1. NMR (CDCl
3): δ 0.33 (s, 3 H, C18-CH
3), 2.4 (s, 3 H, C21-SC(O)CH
3), 2.57 (s, 3 H, C11β-4-phenyl-C(O)CH
3), 4.0 (dd, 2 H, J
1 = 48.6 Hz, J
2 = 18 Hz, C21- CH
2SAc), 4.57 (br d, 1 H, C11α-CH), 5.8 (s, 1 H, C4-CH=), 7.37 (d, 2 H, J = 9 Hz, 2',
6' aromatic-CH's), and 7.93 (d, 2 H, J = 9 Hz, 3', 5' aromatic-CH's). MS(EI) m/z (relative
intensity): 506 (M
+, 29.1), 488 (14.4), 474 (16.6), 431 (100.0) and 346 (78.1). Anal. Calcd. for C
30H
34O
5S·H
2O: C, 68.68; H, 6.92; S, 6.11. Found: C,68,99; H, 6.73; S, 6.06.
Step 2. Preparation of the target compound 106c:
[0058] Under nitrogen, trifluoroacetic anhydride (17.43 g, 82.89 mmol), glacial acetic acid
(7.17 g) 118.45 mmol),
p-toluenesulfonic acidmonohydrate (1.0 g, 5.3 mmol) and dry CH
2Cl
2 (100 mL) were combined and stirred at room temperature for ½h. The mixture was cooled
to 0°C in an ice bath and a solution of the 17α-ol-21-thioacetate (
105e, 3.0 g, 5.92 mmol) in dry CH
2Cl
2 (54 mL) was added. The mixture was stirred at 0°C for 6 hr after which time TLC (4%
acetone/CH
2Cl
2) indicated a complete reaction. The mixture was neutralized with cold saturated NaHCO
3 and extracted with CH
2Cl
2, (3x), The organic fractions were washed with brine (2x), combined, dried over sodium
sulfate and concentrated
in vacuo to give the crude product as a foam. Purification of this material by Flash chromatography
eluting 4% acetone/CH
2Cl
2 followed by crystallization from EtOAc/hexanes gave 2.34 g of the pure compound
106c as a yellow crystalline solid; m.p. = 204 - 205°C. FTIR (KBr, diffuse reflectance):
v
max 2948, 1734, 1702, 1676, 1663 and 1602 cm
-1. NMR(CDCl
3): δ 0.30 (s, 3 H, C18-CH
3), 2.15 (s, 3 H, C17α-OC(O)CH
3), 2.33 (s, 3 H, C21-SC(O)CH
3), 2.57 (s 3 H, C11β-4-phenyl-C(O)CH
3), 3.94 (dd, 2H, J
1= 20.7 Hz, J
2 = 14.4 Hz, C21-
CH2SAc), 4.53 (br d, 1H, C11α-CH), 5.83 (s, 1 H, C4-CH=), 7.37 (d; 2 H, J = 9 Hz, 2',
6' aromatic-CH's), and 7.93 (d, 2 H, J = 9 Hz, 3', 5' aromatic-CH's), MS (EI) m/z
(relative intensity): 548 (M
+, 6.9), 488 (18.4), 413 (27.4), 371 (100.0) and 280 (24.0). Anal. Calcd. for C
32H
36O
6S·1/10H
2O: C, 69.82; H, 6.63; S, 5.82. Found; C, 68.83; H, 6.67, S, 5.59.
EXAMPLE 4
[0059] This example illustrates the preparation and properties of 17α,21-Dimethoxy-11β-(4-acetylphenyl)-19-norpregna-4,9-diene-3,20-dione
(
113d) (
Figure 8):
Step 1. 3,3-Ethylenedioxy-17α-methoxy-21-hydroxy-19-norpregna-5(10),9(11)-dien-20-one (107):
[0060] To a solution of the 17α-methoxy-3-ketal (
94, 10.0 g, 27.1 mmol) in dry THF (150 mL) was added iodobenzene diacetate (
Moriarty, et al., J. Chem. Soc., Chem. Commun., 641-642 (1981);
Velerio, et al., Steroids, 60:268-271 (1995)) (34.59 g, 4x) as a solid. The suspension was stirred under nitrogen and cooled
to 0°C. H
2O (7.73 mL, 429.6 mmol, 16x) was added, followed by 0.5
M KO-tBu solution (1400 mL, 700 mmol, 26x) via transfer needle. (A 50:50 (v/v) mixture
of freshly opened methanol (700 mL) and 1.0 M potassium t-butoxide in THF (700 mL;
Aldrich) was prepared and cooled to 0°C to give a 0.5 M base solution). Upon completion
of addition the reaction mixture was removed from the ice bath and the solution alowed
to warm to room temperature. The reaction was monitored every hour by TLC (5% acetone
in CH
2Cl
2) and after 4 hr, virtually all of the starting material had been converted to approximately
a 80:20 mixture of two more polar components. The reaction mixture was diluted with
H
2O (500 mL) and brine (500 mL) and extracted into ether (3x). Organic fractions were
washed again with H
2O and brine. Combined organic extracts were dried by filtration through Na
2SO
4, evaporated in
vacuo, and further dried under high vacuum to recover 13.84 g of an orange oil. Purification
by flash chromatography (5% acetone in CH
2Cl
2) gave 6.0 g of a pale yellow-white foam (
107) in 57.5% yield. Trituration with pentane produced
107 which was dried under vacuum to recover 5.36 g of a white powder in 51.0% yield;
m.p. = 147 - 152°C. FTTR (KBr, diffuse reflectance): v
max 3478, 2900, 2825, 1712,1437, 1384 and 1372 cm
-1. NMR (300 MHz, CDCl
3): δ 0.550 (s, 3 H, C18-CH
3), 3.159 (s, 3 H, C17α-OCH
3), 3.981 (s, 4 H, C3-O
CH2CH2O), 4.251 and 4.471 (AB, 2 H, J
AB = 19.81 Hz, C21-CH
2) and 5.544 (br s, 1 H, C11-CH=). MS (EI) m/z (relative intensity): 388 (M
+, 54.8), 356 (13.8), 297 (100.0), 211 (65.0), 169 (51.1) and 99 (56.3). Anal. Calcd.
for C
23H
32O
5·1/4H
2O: C, 70.29; H, 8.34. Found: C, 70.21; H, 8.12.
Step 2. 3,3-Ethylenedioxy-17α,21-dimethoxy-19-norpregna-5(10),9(11)-dien-20-one (108):
[0061] To a solution of the 3-ketal-21-hydroxy compound (
107, 5.0 g, 12.87 mmol) in 500 mL of 1,2-dimethoxyethane (DME) was added Proton-Sponge®
[1,8-bis(dimethylamino)naphthalene] (13.79 g, 64.35 mmol, 5x) as a solid. The solution
was cooled to 0°C in an ice water bath and trimethyloxonium tetrafluoroborate (9.52
g, 64.35 mmol, 5x) was added as a solid. The suspension was kept at 0°C under nitrogen,
for 3 hr. At that time, TLC (5% acetone in CH
2Cl
2) indicated all of the starting material had been cleanly converted to the slightly
less polar 3-ketal-17α,21-dimethoxy compound (
108). H
2O and EtOAc were added, the mixture was transferred to a separatory funnel, and the
layers allowed to separate. The organic fraction was washed with ice-cold 1 N HCl
(2x), H
2O (1x), saturated NaHCO
3 (1x), H
2O (1x), and brine (1x). Combind EtOAc extracts (3x) were dried by filtration through
Na
2SO
4 and evaporated
in vacuo. The resulting colorless oil was dried overnight under high vacuum to recover a white
foam (
108, 5.28 g) in quantitative yield. Analysis by TLC and NMR indicated the crude material
was sufficiently pure to carry directly on to the next reaction. A small amount was
triturated with pentane and dried overnight under high vacuum to give 120 mg of
108 as a white solid; m.p = 104-110°C. FTIR (KBr, diffuse reflectance): v
max 2926; 2884, 2828,1722, 1447, 1380, 1322 and 1252 cm
-1. NMR (300 MHz, CDCl
3): δ 0.585 (s, 3 H, C18-CH
3), 3.175 (s, 3 H, C17α-OCH
3), 3.442 (s, 3 H, C21-OCH
3), 3.983 (s, 4 H, C3-O
CH2CH2O), 4.182 and 4.367 (AB, 2 H, J
AB = 18.01 Hz, C21-CH
2) and 5.555 (br s, 1 H, C11-CH=). MS (EI) m/z (relative intensity): 402 (M
+, 27.7), 370 (7.2), 297 (100.0), 211 (62.1), 169 (41.6) and 99 (62.7). Anal. Calcd.
for C
24H
34O
5·3/5H
2O: C, 69.74; H, 8.58. Found: C, 69.82; H, 8.43.
Step 3. 3,3-Ethylenedioxy-17α,21-dimethoxy-19-norpregna-5(10),9(11)-dien-20-ol (109):
[0062] The 3-ketal 17α,21-dimethoxy-20-one (
108, 5.0 g, 12.42 mmol) was dissolved in dry THF (100 mL) and 2 equivalents of LiAlH
4 (25 mL, 25 mmol, 1.0
M in ether) were added
via syringe. The solution was stirred magnetically at room temperature under nitrogen.
After 15 minutes, examination by TLC (5% acetone in CH
2Cl
2) indicated the starting material had been cleanly converted to a single, more polar
product (
109). The reaction mixture was cooled in an ice bath, and saturated Na
2SO
4 (~2 - 3 mL) was added dropwise
via pipette. When the reaction was quenched, several scoops of Na
2SO
4 were added and the mixture allowed to stir 1 hr. Filtration through a sintered glass
funnel, followed by evaporation
in vacuo produced a concentrated syrup. The syrup was taken up in H
2O and CH
2Cl
2, transferred to a separatory funnel, and the layers allowed to separate. The organic
fraction was washed again with brine. Combined CH
2Cl
2 extracts (3x) were dried by filtration through Na
2SO
4 and evaporated
in vacuo. The resulting white foam was dried further under high vacuum to recover 4.69 g of
the crude
109. Purification of this crude product by flash chromatography (5% isopropanol in CH
2Cl
2) gave 4.24 g of 109 as a white foam in 84.4% yield.
[0063] The two purest fractions were combined and taken up in a minimum amount of acetone/hexane.
After standing six days at room temperature, large, colorless crystals had formed.
The crystals were collected by centrifugation, washed with several portions of hexane,
and dried under high vacuum to recover 177 mg. Analysis by TLC (10% acetone in CH
2Cl
2) indicated the crystals were of the highest purity. Analysis of this material by
NMR indicated a single isomer. No further work was done for identification of this
single isomer. A second crop of 78 mg with only a trace of impurity was obtained from
the mother liquors; m.p. =111- 115°C. FTIR (KBr, diffuse reflectance): v
max 3576, 3456, 2930, 2891, 2827, 1460 and 1372 cm
-1. NMR (300 MHz, CDCl
3): δ 0.824 (s, 3 H, C18-CH
3), 3.298 (s, 3 H, C17α-OCH
3), 3.392 (s, 3 H, C21-OCH
3), 3.416 (dd, 1 H, J
1 = 9.30 Hz, J
2 = 8.10 Hz, C21-CH
2), 3,490 (dd, 1 H, J
1 = 9.30 Hz, J
2 = 3.30 Hz, C21-CH
2), 3.923 (dd, 1 H, J
1 = 8.10 Hz, J
2 = 3.30 Hz, C20-CH), 3.980 (s, 4 H, C3-O
CH2CH2O) and 5.595 (br s, 1 H, C11-CH=). MS (EI) m/z (relative intensity): 404 (M
+, 2.1), 372 (5.7), 329 (1.7), 297 (100.0) and 211 (35.7). Anal. Calcd. for C
24H
36O
5·1/5C
6H
14: C, 71.76; H, 9.27. Found: C, 71.83; H, 9.04.
Step 4. 3,3-Ethylenedioxy-5α,10α-epoxy-17α,21-dimethoxy-19-norpregn-9(11)-en-20-ol (110):
[0064] To a solution of hexafluoroacetone (2.01 mL, 14.39 mmol) in CH
2Cl
2 (50 mL), was added solid Na
2HPO
4 (1.36 g, 9.59 mmol) and 30% H
2O
2 (2.16 mL, 21.1 mmol). The mixture was transferred to the cold room and stirred vigorously
for % hr at 4°C. A chilled solution of the 20-alcohol (
109, 3.88 g. 9.59 mmol) in CH
2Cl
2 (25 mL) was added via pipette and rinsed in with additional CH 2Cl
2 (25 mL). After stirring overnight at 4°C, TLC (7.5% acetone in CH
2Cl
2) indicated virtually all of the starting material had been converted to one major,
more polar product with only a trace of byproducts. The reaction mixture was transferred
to a separatory funnel and washed with 10% Na
2SO
3 (1x), H
2O (1x), and brine (1x). Combined CH
2Cl
2 extracts (3x) were dried by filtration through Na
2SO
4 and evaporated
in vacuo to recover a foam. NMR analysis of the crude material indicated the a and β epoxides
were present in approximately a 9:1 ratio. Trituration with ether produced 2.27 g
of the pure 5α,10 α epoxide (
110) as a white powder in 56.3% yield; m.p. =146 -153°C. FTIR (KBr, diffuse reflectance):
v
max 3558, 2939, 1638,1446,1373 and 1247 cm
-1. NMR (300 MHz, CDCl
3): δ 0.824 (s, 3 H, C18-CH
3), 3.273 (s, 3 H, C17α-OCH
3), 3.389 (s, 3 H, C21-OCH
3), 3.402 (dd, 1 H, J
1 = 9.61 Hz, J
2 = 8.10 Hz, C21 -CH
2), 3,476 (dd, 1 H, J
1 =9.1 Hz, J
2 =3.30Hz, C21-CH
2), 3.908 (m, 5 H, C3-O
CH2CH2O and C20-CH) and 6.053 (brs, 1 H, C11-CH=). MS (EI) m/z (relative intensity): 420
(M
+, 1.7), 402 (6.0), 370 (6.2), 345 (20.0), 313 (77.8), 295 (100.0) and 99 (95.4). Anal.
Calcd. for C
24H
36O
5·1/10H
2O: C, 68.25; H, 8.64. Found: C, 68.31; H, 8.71.
Step 5: 3,3-Ethylenedioxy-5α-hydroxy-11β-[4-(2-methyl-1,3-dioxolan-2-yl)phenyl]-17α,21-dimethoxy-19-norpregn-9-en-20-ol
(111d):
[0065] Magnesium turnings (289 mg, 11.89 mmol) were weighed into a 100 mL round bottom two-neck
flask equipped with a reflux condenser, a magnetic stirrer, and a rubber septum, A
small crystall of iodine was added and the system was flushed with nitrogen and flame
dried, After cooling to room temperature, freshly distilled THF (10 mL) was introduced
via syringe followed by a small amount of dry dibromoethane (~0.1 mL). After evidence
of reaction was observed (disappearance of I
2 color, and bubble formation on metal), a solution of the ketal of 4-bromoacetophenone
(
see, Example 20, Step 1) (2.89 g, 11.89 mmol) in dry THF (10 mL) was added via syringe.
The mixture was then stirred in a hot water bath for 2 hr until the majority of the
magnesium was consumed. After the reaction mixture was cooled to room temperature,
solid copper (I) chloride (11.8 mg, 1.19 mmol) was added and the mixture was stirred
at room temperature for ½ hr. The epoxide (
110, 1.0 g, 2.38 mmol) in dry THF (10 mL) was added via syringe. The reaction mixture
was stirred at room temperature for 1 hr then quenched with the addition of saturated
NH
4Cl solution (~20 mL), and the mixture was stirred at room temperature for ½ hr while
air was drawn through the reaction mixture to oxidize Cu(I) to Cu(II). The contents
of the flask were diluted with water (~100 mL) and extracted with CH
2Cl
2 (3x). The organic extracts were washed with saturated NH
4Cl solution (1x), water (1x) and brine (1x), then dried over anhydrous sodium sulfate,
filtered and concentrated
in vacuo to yield 4.3 g of oil. This was purified on a flash column (10% acetone in CH
2Cl
2) to yield 850 mg of
111d as a white foam which was triturated with ether to produce a white crystalline solid
in 61.2% yield; m.p. = 145 - 150°C (Material changed to amber gel) and gel melts at
173 - 177°C. FTIR (KBr, diffuse reflectance): v
max 3461, 2946, 2877, 2812, 1663, 1602, 1540, 1505, 1457 and 1372 cm
-1. NMR (300 MHz, CDCl
3): δ 0.443 (s, 3H, C18-CH
3), 1.636 (s, 3 H, CH
3 of acetophenone ketal), 3.289 (s, 3 H, C17α-OCH
3), 3.358 (s, 3 H, C21-OCH
3), 3.741-4.015 (m, 8 H, C3- and C11β-4-acetyl ketals), 4.244 (br s, 1 H, C11α-CH),
7.165-7.327 (dd, 4 H, aromatio-CH's). MS (EI) m/z (relative intensity): 584 (M
+). Anal. Calcd. for C
34H
48O
8: C, 69.86; H, 8.22. Found: C, 69.63; H, 8.28.
Step 6: 3,3-Ethylenedioxy-5α-hydroxy-11β-[4-(2-methyl-1,3-dioxolan-2-yl)phenyl]-17α,21-dimethoxy-19-norpregn-9-en-20-one (112d):
[0066] Under nitrogen, IBX (1.149 g, 4.104 mmol) was dissolved in DMSO (8 mL) over a period
of 10 min. A solution of the Grignard product (
111d, 800 mg, 1.368 mmol) in DMSO (8 mL) was added
via pipette to the above solution and the reaction mixture stirred at room temperature
for ½ hr. At that time, TLC (10% acetone in CH
2Cl
2; aliquot was diluted in water and extracted into EtOAo) showed the starting material
had been converted to a single less polar product. The reaction was diluted with H
2O (~150 mL) and extracted with CH
2Cl
2 (3x). The organic layers were washed with H
2O (1x) and brine (1x), dried over anhydrous sodium sulfate, filtered and concentrated
in vacuo to give 820 mg of
112d as an off-white foam. This was purified on a flash column (10% acetone in CH
2Cl
2). The product was originally obtained as a foam and was triturated with pentane and
dried
in vacuo to yiled 540 mg of
112d as a white solid in 73% yield; m.p. = 102 -106°C (shrinkage to an amber gel); 111
- 113°C (gel bubbles); 123 - 133°C (gel melts). FTIR (KBr, diffuse reflectance): v
max 3526, 2939, 2884, 2825, 1722, 1665 and 1604 cm
-1. NMR (300 MHz, CDCl
3): δ 0.190 (s, 3 H, C18-CH
3), 1.625 (s, 3 H, CH
3 of acetophenone ketal), 3.146 (s, 3 H, C17α-OCH
3), 3.445 (s, 3 H, C21-OCH
3), 3.742 and 4.015 (m, C3 and C11β-4-acetylphenyl ketals), 4.310 (d, 1 H, C11α-CH),
7.119 - 7.332 (dd, 4 H, aromatic-CH's) MS (EI) m/z (relative intensity): 582 (M
+), Anal. Calcd. for C
34H
46O
8: C, 70.08; H, 7.96 Found: C, 70.11; H, 8.01. FTIR (KBr, diffuse reflectance); v
max 3526, 2939, 2884, 2825, 1722, 1665 and 1604 cm
-1. NMR (300 MHz, CDCl
3); δ 6.190 (s, 3H, C18-CH
3), 1.625 (s, 3 H, CH
3 of acetophenone ketal), 3.416 (s, 3 H, C17α-4CH
3), 3.445 (s, 3 H, C21-OCH
3), 3,742 and 4,015 (m, C3 and C11β-4-acetylphenyl ketals), 4.310 (d, 1 H, C11α-CH),
7.119-7.332 (dd, 4 H, aromatic-CH). MS (EI) m/z (relative intensity): 582 (M
+). Anal. Calcd. for C
34H
46O
8: C, 70.08; H, 7.96 Found: C, 70.11; H, 8.01.
Step 7. Preparation of the target compound 113d:
[0067] Nitrogen was bubbled through a mixture of EtOH (925 mL) and 8.5% sulfuric acid for
½ hr to remove oxygen. The 20-ketone (
112d, 520 mg, 0.892 mmol) was added as a solid with stirring to the above solution. The
mixture was put into an oil bath preheated to 95 °C and was refluxed under nitrogen
for 1 hr. The reaction mixture was cooled in an ice bath and quenched with saturated
K
2CO
3 solution (pH ≅ 10), diluted with water (~125 mL) and extracted with CH
2Cl
2 (3x). The organic fractions were washed with water and brine, dried over anhydrous
Na
2SO
4, filtered and concentrated
in vacuo to give 460 mg of the crude product, Flash chromatography (10% acetone in CH
2Cl
2) gave 377 mg of an off-white pale yellow solid. This was crystallized from mixture
of distilled ether and CH
2Cl
2 to yield 360 mg of
113d in 81% yield as a white crystalline solid in two batches. The product
113d retained CH
2Cl
2 and required extreme drying: m.p. = 133-136°C (foams) and 172-178°C (foam melts).
FTIR (KBr, diffuse reflectance): v
max 2942, 1719, 1681, 1665, 1600, 1409, 1359 and 1272 cm
-1. NMR (300 MHz, CDCl
3): δ 0.264 (s, 3 H, C18-CH
3), 2.571 (s, 3 H, CH
3 of acetophenone ketal), 3.185 (s, 3 H, C17α-OCH
3), 3.449 (s, 3 H, C21-OCH
3), 4.183 and 4.385 (dd, 2 H, C21-CH
2-), 4.456 and 4.481 (d, 1 H, C11α-CH), 5.90 (s, 1 H, C4-CH=), 7.247 - 7.7883 (dd,
4H, aromatic-CH's). MS (EI) m/z (relative intensity): 476 (M
+, 35), 403 (93), 371 (100), 331 (67) and 91 (26). Anal. Calcd. for C
30H
36O
5: C, 75.63; H, 7.56. Found: C, 74.78; H, 7.58.
EXAMPLE 5
[0068] This example illustrates the preparation and properties of 17α-Acetoxy-11β-(4-acetylphenyl)-21-methoxy-19-norpregna-4,9-diene-3,20-dione
(
123b):
Step 1. 17α-Hydroxy-21-chloro-19-norpregna-4,9-diene-3,20-dione (115):
[0069] The 3-ketal cyanohydrin (
98, 50g, 73.22 mmol) was magnetically stirred with freshly distilled THF (550 mL) under
nitrogen at room temperature. 4-Dimethylaminopyridine (DMAP) (4.47 g, 36.59 mmol)
was added as a solid. Freshly distilled Et
3N (27.60 mL, 197.68 mmol) followed by freshly distilled chloro-(chloromethyl)dimethylsilane
(25.1 mL, 190.36 mmol) was added
via syringe. The reaction was allowed to stir overnight at room temperature. The next
day TLC on silica (2% acetone in CH
2Cl
2) showed all starting material had been converted to the silyl ether. The reaction
mixture was cooled to -78°C in a dry ice bath with isopropanol, and then diluted with
THF (800 mL). Lithium diisopropylamide (LDA) (2.0
M, 300 mL, 600 mmol) was added dropwise to the reaction
via an additional funnel over a period of 45 min. Once addition was complete, the reaction
was stirred for 1.5 hr at -78°C, HCl (4
N, 1250 mL, 5 mol) was added
via the addition funnel. The dry ice bath was removed, and the reaction was allowed to
stir overnight at room temperature. The reaction mixture was then cooled to 0°C and
neutralized by the addition of concentrated NH
4OH (305 mL). The mixture was transferred to a separatory funnel and extracted with
EtOAc (3x), washed with H
2O (2x) and brine (1x). The organic fractions were combined, filtered through Na
2SO
4 and evaporated
in vacuo. The resulting solid was triturated with ether (1000 mL), collected on a Buchner funnel,
and washed with additional ether. After drying overnight
in vacuo, 38.90 g of 115 as a dark yellow solid was recovered in 76.61% yield. Analysis by
TLC on silica (5% acetone in CH
2Cl
2) showed the material was suitable to carry directly on to the next reaction; m.p.
= 204 - 207°C. FTIR (KBr, diffuse reflectance): v
max 3465, 2946, 1729, 1664, 1599 and 1573 cm
-1. NMR (300 MHz, CDCl
3): δ 0.833 (s, 3 H, C18-CH
3), 4.352 and 4.655 (AB, 2 H, J
AB = 16.8 Hz, C21-CH
2) and 5.687 (s, 1 H, C4-CH=) MS (EI) m/z (relative intensity): 350 (M
+, 33.1), 348 (100.0), 253 (63.7), 213 (71.5) and 91 (62.6).
Step 2. 17α-Hydroxy- 21-acetoxy-19-norpregna-4,9-diene-3,20-dione (116):
[0070] The 21-chloro compound (
115, 37.90 g, 108.64 mmol), KOAc (111.83 g, 1139.63 mmol) and acetonitrile (927 mL) were
mechanically stirred. The suspension was brought to reflux under nitrogen. After 2.5
hr, TLC on silica (5% acetone in methylene chloride) indicated the reaction had gone
to completion. The reaction mixture was allowed to cool to room temperature, and precipitated
KCl was removed by filtration through a sintered glass funnel. Acetonitrile was evaporated
in
vacuo, and the resulting residue was taken up in CH
2Cl
2 and H
2O. The mixture was transferred to a separatory funnel, extracted with CH
2Cl
2 (3x), and washed with H
2O (2x) and brine (1x). The organic fractions were combined, filtered through Na
2SO
4 and evaporated
in vacuo to give 36.26 g of
116 in 89.61% crude yield. The solid material was taken up in hot acetone (150 mL) and
CH
2Cl
2 (150 mL). The solution was scratched, seeded and stored in the freezer for 4 hr.
The crystals were then filtered through a Buchner funnel and dried
in vacuo to recover 10.71 g of the 17α-ol-21-acetate (
116) in 52.14% yield. The mother liquor was evaporated
in vacuo and purified by flash column chromatography eluted with 10% acetone in CH
2Cl
2. Fractions containing the 17α-ol-21-acetate (
116) were combined and evaporated
in vacuo to recover 2.58 g of a golden yellow solid in 12.61%. The total yield of the purified
17α-ol-21-acetate (
116) was 13.29 g of a golden yellow solid in 64.7% yield; m.p. = 213 - 218°C. FTIR (KBr,
diffuse reflectance): v
max 3475, 2947, 2951, 1744, 1720, 1646, 1606, 1578, 1367 and 1235 cm
-1. NMR (300 MHz, CDCl
3): δ 0.841 (s, 3 H, C18-CH
3), 2.182 (s, 3 H, C21-OAc), 4.868 and 5.081 (AB, 2 H, J
AB = 17.4 Hz, C21-CH
2) and 5.683 (s, 1H, C4-CH=) MS (EI) m/z (relative intensity): 372 (M
4+, 78.3), 354 (9.7), 312 (75.6), 253 (100.0) and 91 (69.3).
Step 3. 17α,21-Dihydroxy-19-norpregna-4,9-diene-3,20-dione (117):
[0071] The 17α-ol-21-acetate (
116) (35.15 g, 94.37 mmol) was suspended in freshly opened MeOH (2870 mL) and deoxygenated
by bubbling nitrogen through the mixture for 45 min. KHCO
3 (deoxygenated, 0.5
M, 283 mL, 141.74 mmol) was added, and the suspension was mechanically stirred and
brought to reflux under nitrogen. After 10 minutes at reflux, TLC on silica (5% isopropanol
in CH
2Cl
2) showed the reaction to be complete. The reaction mixture was cooled to room temperature,
neutralized by the addition of HOAc (8.15 mL), and MeOH was evaporated
in vacuo. The reaction mixture was extracted with CH
2Cl
2 (3x), and washed with H
2O (2x) and brine (1x). The combined organic fractions were filtered through Na
2SO
4 and evaporated
in vacuo to recover 29.83 g of the solid in 95.7% yield. The solid was taken up in acetone
with a small amount of CH
2Cl
2. The solution was scratched, seeded and stored in the freezer for 1 hr. The resulting
crystals were collected on a Buchner funnel, rinsed with acetone and dried
in vacuo to recover the first crop. The mother liquor was concentrated and stored in the freezer
overnight to afford a second crop of crystals. The combined solid recovered was 16.15
g in 51.8% crude yield. The mother liquors were evaporated
in vacuo and purified by flash column chromatography eluted with 5% isopropanol in CH
2Cl
2. Fractions containing the diol (
117) were combined and evaporated
in vacuo to recover 4.86 g. The total yield of
117 was 19.75 g of a light yellow solid in 76.7%; m.p. = 197 - 204°C. FTIR (KBr, diffuse
reflectance): v
max 3917, 2954, 2869, 1715, 1635, and 1590 cm
-1. NMR (300 MHZ, CDCl
3): δ 0.827 (s, 3 H, C18-CH
3), 4.323 and 4.690 (AB, 2 H, J
AB = 19.81 Hz, C21-CH
2) and 5.686 (s, 1 H, C4-CH=). MS (EI) m/z (relative intensity): 330 (M
+, 100.0), 312 (10.1), 253 (61.7), 213 (64.5), 174 (26.1) and 91. (38.5).
Step 4. 3,20-bis-Ethylenedioxy-17α,21-Dihydroxy-19-norpregna-5(10),9(11)-diene (118):
[0072] The diol (
117, 9.88 g, 29.89 mmol) and freshlyopened ethylene glycol (750 mL) were magnetically
stirred.
p-Toluenesulfonic acid monohydrate (0.49 g, 2.60 mmol) was added to the suspension
as a solid. The ethylene glycol was distilled
in vacuo at 81°C under 2 mm Hg. After distilling for 3 hr, the mixture was cooled to room
temperature and poured into saturated NaHCO
3 (250 mL) and H
2O (250 mL). The mixture was extracted with CH
2Cl
2 (3x), washed with H
2O (2x) and brine (1x). The organic fractions were combined, filtered through sodium
sulfate and evaporated
in vacuo to recover a solid. Analysis by TLC on silica (5% isopropanol in CH
2Cl
2) showed all of the starting material to be converted to an 85:15 mixture of 3,20-diketal
to 3-ketal with a small amount of by-product. The resulting solid was triturated with
ether, collected on a Buchner funnel, washed with additional ether and dried
in vacuo to recover 6.46 g of
118 in 51.64% yield. The mother liquor was evaporated
in vacuo and purified through flash chromatography eluting with 4% isopropanol in CH
2Cl
2. This recovered 0.6 g of the light beige, solid diketal in 4.8% yield. The total
yield of the solid diketal (
118) was 7.06 g of a light beige solid in 56.44% yield; m.p. =173 -176°C. FTIR (KBr,
diffuse reflectance): v
max 3452, 2892,1652, 1436, 1370, 1223 and 1055 cm
-1. NMR (300 MHz, CDCl
3): δ 0.795 (s, 3 H, C18-CH
3), 3.686 and 3.894 (AB, 2 H, J
AB =12.61 Hz, C21-CH
2), 3.987 (s, 4 H, C3-O
CH2CH2O-), 4.130 (m, 4 H, C20-O
CH2CH2O-) and 5.555 (br s, 1 H, C11-CH=). MS(EI) m/z (relative intensity): 418 (M
+, 5.6), 400 (0.7), 387 (3.9), 314 (3.5), 211 (4.6) and 103 (100.0).
Step 5. 3,20-bis Ethylenedioxy-17α-hydroxy-21-methoxy-19-norpregna-5(10),9(11)-diene (119):
[0073] To a solution of the diketal (
118, 0.5 g, 1.19 mmol) in CH
2Cl
2 (50 mL) was added 1,8-bis-(dimethylamino)naphthalene ("Proton Sponge", 1.28 g, 5.97
mmol) followed by trimethyloxonium tetrafluoroborate (0.88 g, 5.97 mmol). The mixture
was mechanically stirred in an ice bath under nitrogen. The ice bath was allowed to
melt to bring the reaction to room temperature. The reaction mixture was stirred for
3 hr, at which time TLC (5% isopropanol in CH
2Cl
2) indicated the reaction had gone to completion. The mixture was poured into a separatory
funnel and washed with H
2O (2x). The CH
2Cl
2 extracts (3x) were combined, filtered through Na
2SO
4 and evaporated
in vacuo. The resulting residue was taken up in EtOAc, washed with ice-cold 1
N HCl (2x), H
2O (1x), saturated NaHCO
3 (1x), H
2O (1x), and brine (1x). Combined EtOAc fractions (3x) were filtered through Na
2SO
4 and evaporated
in vacuo to give 0.5 g of
119 as a yellow foam in 97.14% yield. The material was of adequate purity to carry onto
the subsequent epoxidation. The reaction was repeated to produce a total of 13.57
g of the 21-methoxy compound (
119). NMR (300 MHz, CDCl
3): δ 0.798 (s, 3 H, C18-CH
3), 3.415 (s, 3 H, C21-OCH
3), 3.546 and 3.715 (AB, 2 H, J
AB = 10.51 Hz, C21-CH
2), 3.985 (s, 4 H, C3-O
CH2CH2O-), 4.05 (m, 4 H, C20-O
CH2CH2O-) and 5.54 (br s, 1 H, C11-CH=). Decomposition of analytical sample precluded further
analysis.
Step 6. 3,20-bis-Ethylenedioxy-5α,10α-epoxy-17α-hydroxy-21-methoxy-19-norpregn-9(11)-ene
(120):
[0074] Hexafluoroacetone trihydrate (6.49 mL, 46.64 mmol) and CH
2Cl
2 (100 mL) were mechanically stirred vigorously at 4°C. Solid Na
2HPO
4 (3.67 g, 25.91 mmol) and 30% H
2O
2 (7.01 mL, 68.39 mmol) were added and stirred for 15 minutes at 4°C. A cold solution
of the 21-methoxy compound (
119, 13.45 g, 31.09 mmol) in CH
2Cl
2 (100 mL) was added to the mixture via an additional funnel over a period of 1 hr.
The reaction mixture was allowed to stir overnight at 4°C. Examination by TLC (25%
EtOAc in CH
2Cl
2) showed all of the starting material had been converted to a mixture of the α and
β epoxides in about a 2:1 ratio. The mixture was transferred to a separatory funnel
and washed with 10% Na
2SO
3 (1x), saturated NaHCO
3 (1x) and H
2O (1x), Combined CH
2Cl
2 extracts (3x) were filtered through Na
2SO
4 and evaporated
in vacuo to recover 14.06 g of the epoxide (
120) as a white foam in quantitative yield. The 2:1 mixture of α- and β- epoxides was
used directly for the subsequent Grignard reaction. NMR (300 MHz, CDCl
3): δ 0.700 (s, 3 H, C18-CH
3), 3.407 (s, 3 H, C21-OCH
3), 3.539 and 3.692 (AB, 2 H, J
AB = 10.51 Hz, C21-CH
2), 4.051 (m, 8 H, C3- and C20-O
CH2CH2O-), 5.819 (br s, 0.3 H, C11-CH= of β-epoxide), and 5.997 (br s, 0.6 H, C11-CH= of
α-epoxide). Decomposition of analytical sample precluded further analysis.
Step 7. 3,20-bis-Ethylenedioxy-5α,17α-dihydroxy-11β-[4-(2-methyl-1,3-dioxolan-2-yl)phenyl]-21-methoxy-19-norpregn-9-ene
(121b):
[0075] A 3-neck 1 L flask was euipped with a mechanical stirrer, an addition funnel, and
a reflux condenser and flame-dried under a stream of nitrogen, Magnesium (3.90 g,
146 mmol) was added, followed by one iodine crystal, 150 mL of dry THF, and 1-2 drops
of 1,2-dibromoethane. The mixture was stirred under nitrogen and heated in a warm
water bath, but no reaction occurred, 4-Bromoacetophenone ethylene ketal (
see, EXAMPLE 1, Step 3) (35.5 g, 146 mmol) was added as a solution in THF (100 mL) via
the addition funnel and then rinsed in with additional THF (40 mL). Upon completion
of addition, the mixture was heated to reflux to initiate formation of the Grignard
reagent. Heating was discontinued and the mixture allowed to stir 1.5 hr as the water
bath gradually cooled to room temperature. Copper (I) chloride (1.59 g, 16.06 mmol)
was added as a solid and stirring continued for another ½ hr. The mixture of epoxides
(
120, 13.11 g, 29.2 mmol, ∼66% α-epoxide) was added as a solution in THF (50 mL) via the
addition funnel and rinsed in with additional THF (20 mL). After stirring 1.5 hr at
room temperature, TLC (20% acetone in CH
2Cl
2; quenched with saturated NH
4Cl and extracted into EtOAc) indicated the reaction was >95% complete. The reaction
was quenched by the addition of 200 mL of saturated NH
4Cl and air was drawn through the mixture for ½ hr with vigorous stirring. Ether was
added, the mixture was transferred to a separatory funnel, and the layers allowed
to separate. The organic layer was washed with 10% NH
4Cl, H
2O and brine. Combined ether extracts (3x) were filtered through Na
2SO
4 and evaporated in
vacuo to give 35.23 g of the crude product (
121b). Purification by flash column chromatography (20% acetone in CH
2Cl
2) afforded 7.24 g of a pale foam. Trituration of this foam with ether and pentane
produced 5.93 g of the product (
121b) as a beige powder in 50.2% yield (based on 66% of the mixture as α-epoxide). NMR
(CDCl
3): δ 0.4 (s, 3 H, C18-CH
3), 1.63 (s, 3 H, CH
3 of C11β-4-C
6H
4C(O)CH
3), 3.45 (s, 3 H, C21-OCH
3), 3.57 - 4.40 (m, 15 H, C3-O
CH2CH2O-, C11β-O
CH2CH2O- and C20- O
CH2CH2O-, C11α-CH and C21-CH
2-), 7.2 (d, 2 H, J = 9 Hz, 2', 6' aromatic-CH's) and 7.83 (d, 2 H, J = 9 Hz, 3', 5'
aromatic-CH's). MS (EI) m/z (relative intensity): 612 (M
+, 0.1), 594 (3.3), 549 (15.0), 459 (2.7), 117 (100.0) and 87 (74.7). Decomposition
of the analytical sample precluded further analysis.
Step 8. -17α-Hydroxy-11β-(4-acetylphenyl)-21-methoxy-19-norpregna-4,9-diene-3,20-dione
(122b):
[0076] The Grignard adduot (
121b, 5.81 g, 9.48 mmol) was dissolved in THF (60 mL) and stirred magnetically, under
nitrogen, at room temperature. Trifluoroacetic acid (180 mL) was added followed by
H
2O (60 mL). After 1.5 hr, examination by TLC (20% acetone in CH
2Cl
2; neutralized with NH
4OH before developing) indicated all of the starting material had been converted to
a slightly less polar product. The reaction mixture was neutralized by the careful
addition of NH
4OH (165 mL)
via an addition funnel. Enough additional NH
4OH was added to bring the pH to 7.0 by pH paper. H
2O was added, the mixture was transferred to a separatory funnel, and extracted with
BtOAo. The organic fraction was washed again with H
2O and brine. Combined EtOAc fractions (3x) were filtered through Na
2SO
4 and evaporated
in vacuo to give
6.60 g of a foam. Purification of the crude product by flash column chromatography (20%
acetone in CH
2Cl
2) afforded a yellow solid (
122b). Crystallization from a minimum amount of hot EtOAc gave large, bright yellow crystals.
The crystals wore collected on a Buchner funnel and dried overnight under high vacuum
at 70°C to recover 2.84 g of
122b. A TLC of the mother liquors indicated they were pure enough to carry on to the subsequent
reaction. The mother liquors were evaporated
in vacuo and dried under high vacuum over the weekend to recover 0.46 g. The total yield of
the 17α-OH (
122b) was 3.3 g as bright yellow crystals in 75.25% yield. A small amount of the crystalline
product was dried
in vacuo at 110°C over the weekend for purposes of characterization. The crystals were fused
and pulverized with a spatula; m.p. = 105 - 109°C (softens). Analysis by HPLC on a
Phenomenex Prodigy 5 ODS-2 column (150 x 4.6 mm) oluted with 50% CH
3CN in H
2O at a flow rate of 1 mL per min and λ = 302 nm indicated a purity of >99% with a
retention time (t
R) of 5.02 min. FTIR (KBr, diffuse reflectance): v
max 3444, 2944, 1722, 1662, 1602, 1407 1359 and 1.271 cm
-1. NMR (CDCl
3): δ 0.33 (s, 3 H, C18-CH
3), 2.57 (s, 3 H, C11β-4-C
6H
4-C(O)CH
3), 3. 47 (s, 3 H, C21-OCH
3), 4.23 - 4.47 (AB, 2 H, J
AB = 18 Hz, C21-CH
2-), 4.52 (br d, 1 H, C11α-CH), 5.48 (s, 1 H, C4-CH=), 7.3 (d, 2 H, J = 9 Hz, 2', 6'
aromatic-CH's) and 7.92 (d, 2 H, J = 9 Hz, 3', 5' aromatic-CH's). MS (EI) m/z (relative
intensity): 462 (M
+, 100.0), 430 (11.2), 389 (27.0), 346 (97.9) and 91 (22.3). Anal. Calcd. for C
29H
34O
5·9/20C
4H
8O
2: C, 73.66; H, 7.55. Found: C, 73.66; H, 7.29.
Step 9. Preparation of the target compound 123b:
[0077] A mixture of trifluoroacetic anhydride (32.78 g, 156 mmol) and acetic acid (9.38
g, 156 mmol) in CH
2Cl
2 (100 mL) was allowed to stir ½ hr at room temperature under nitrogen. The mixture
was cooled to 0°C in an ice H
2O bath and
p-toluenosulfonic acid monohydrate (1.30 g, 6.86 mmol) was added as a solid. The 17α-OH
(
122b, 2.89 g, 6.24 mmol) was added as a solution in 25 mL of CH
2Cl
2 and rinsed in with additional CH
2Cl
2 (25 mL). After 45 min, TLC (10% acetone in CH
2Cl
2) indicated the reaction had gone to completion. The reaction was neutralized by the
careful addition of NH
4OH (31.6 mL, 416 mmol). Additional NH
4OH was added to bring the pH to 7 by pH paper. Water was added and the mixture transferred
to a separatory tunnel. The organic fractions were washed with H
2O and brine. Combined CH
2Cl
2 extracts (3x) were filtered through Na
2SO
4 and evaporated
in vacuo to recover 3.13 g of crude material, Purification by flash chromatography (10% acetone
in CH
2Cl
2) provided 1.56 g of a crystallizing oil. Additional fractions containing a small
amount of a less polar impurity were also combined and evaporated to give 1.04 g of
an oil. Pure fractions were crystallized from a minimum amount of boiling EtOAc, triturated
with pentane and dried 3 nights in a drying pistol at 110°C to give 0.99 g of
123b as pale yellow crystals. The crystals fused at this temperature, but were readily
pulverized for analysis. Mother liquors were combined with the impure fractions and
crystallized from EtOAc to give an additional 0.9 g. Total yield of
123b was 1.89 g as a pale yellow solid in 60.1% yield; mp. = 113°C (softens).
[0078] Analysis by HPLC on a Phenomenex Prodigy 5 ODS-2 column (150 x 4.6 mm) eluted with
50% CH
3CN in H
2O at a flow rate of 1 mL per min and λ = 302 nm indicated a purity of 99.7% with a
retention time (t
R) of 7.69 min. FTIR (KBr, diffuse reflectance): v
max 2942, 1730, 1680,1602, 1432,1408,1368 and 1266 cm
-1, NMR (CDCl
3): δ 0.33 (s, 3 H, C18-CH
3), 2.10 (s, 3 H, C17α-OAc), 2.57 (s, 3 H, C11β-C(O)CH
3), 3. 42 (s, 3 H, C21-OCH
3), 4.07 & 437 (AB, 2 H, J
AB = 18·Hz, C21-CH
2-), 4.50 (brd, 1 H, C11α-CH), 5.83 (
s, 1 H, C4-CH=), 7.28 (d, 2H, J = 9 Hz, 2', 6' aromatic-CH's) and 7.92 (d, 2 H, J =9
Hz, 3',5' axomatic-CH's). MS (EI) m/z (relative intensity): 504 (M
+, 3,3), 447 (17.9), 389 (28.4), 371 (100.0) and 91 (13.8). Anal. Calcd. for C
31H
36O
6'1/6CH
2Cl
2·1/2H
2O: C, 70.92; H, 7.13. Found: C, 71.06; H, 6.91.
Biological Properties of the Compounds of the invention
MATERIALS AND METHODS
Statistical Analysis
AntiMcGinty Test (McGinty, et al., Endocrinology, 24:829-832 (1939))
[0080] Immature female rabbits of the New Zealand White breed (approx. 1 kg body weight)
were maintained under standard laboratory conditions and received a subcutaneous injection
of 5 µg estradiol in 10% ethanol/sesame oil daily for 6 consecutive days. Twenty-four
hours after the last injection of estradiol (day 7) animals underwent sterile abdominal
surgery to ligate a 3-4 cm segment of both uterine horns. The experimental compound
in appropriate solvent (usually 10% ethanol/sesame oil) was injected intraluminally
into the ligated segment of one uterine horn and the vehicle alone into the ligated
segment of the contralateral horn. Injection volume was limited to 0.1 ml, and care
was taken to prevent leakage. A stimulating dose of progesterone (0.8 mg/day) was
administered subcutaneously to each rabbit daily for the next three days (days 7,
8 and 9) for the purpose of inducing endometrial proliferation. All animals were sacrificed
on day 10 when a segment central to the ligatures was removed and fixed in 10% neutral
buffered formalin and submitted for histological processing. Five micron sections
stained with hematoxylin and eosin (H&E) were evaluated microscopically for the degree
of endometrial glandular proliferation according to the method of McPhail (
McPhail, J. Physiol., 83:145 (1934). The percent inhibition of endometrial proliferation for each rabbit was calculated
and the mean of the group of five animals recorded.
AntiClauberg Test (Clauberg, C., Zentr. Gynakol., 54:2757-2770 (1930))
[0081] Immature female rabbits of the New Zealand White breed (approx. 1 kg body weight)
were maintained under standard laboratory conditions and received a subcutaneous injection
of 5 µg estradiol in 10% ethanol/sesame oil daily for 6 consecutive days. Twenty-four
hours after the last dose of estradiol (day 7) animals received progesterone by subcutaneous
injection (0.8 mg/day) and the experimental compound in appropriate vehicle (usually
10% ethanol/sesame oil) orally or subcutaneously for five consecutive days. One group
of rabbits received progesterone only. Twenty-four hours after the last dose all animals
were sacrificed for removal of the uterus which was cleaned of all fat and connective
tissue, weighed to the nearest 0.2 mg and placed in 10% neutral buffered formalin
for subsequent histological processing. Five micron sections stained with hematoxylin
and eosin (H&E) were evaluated microscopically for the degree of endometrial glandular
proliferation according to the method of McPhail (McPhail,
supra). The percent inhibition of endometrial proliferation at each dose level of the experimental
compound was derived by comparison with the progesterone-stimulated animals alone.
Postcoital Test
[0082] Adult female rats of the Sprague-Dawley strain were maintained under standard laboratory
conditions, 14 hours of light and 10 hours of darkness each day and cohabited with
proven fertile males when in proestrus. Sperm-positive animals were randomly assigned
to control and experimental groups. The day vaginal sperm were found in vaginal washings
constituted day 0 of gestation. Rats received experimental compounds or vehicle (control)
daily by the oral route on days 0-3 or 4-6. and were sacrificed between days 10 and
17 to record the number and condition of conceptuses.
Antiovulatory Test
[0083] Immature female rats of the Sprague-Dawley strain weighing 200 to 250 g were maintained
under standard laboratory conditions, 14 hours of light and 10 hours of darkness each
day. Vaginal washings were obtained daily and evaluated microscopically to establish
the estrous cycle of each animal. Animals exhibiting two consecutive four-day cycles
were used in the test Each dose group consisted of eight rats and one group served
as the vehicle control. Animals were dosed at noon on the day of proestrus and sacrificed
24 hours later when ova can usually be visualized in the distended ampulla of the
oviduct using a dissecting microscope. The oviducts were excised, an incision made
in the distended ampulla and the ova teased out in a drop of water on a microscope
slide so that the number shed could be counted. Historically, control animals shed
between 12 and 14 ova during each estrous cycle. Agents which inhibit ovulation usually
exhibit an "all or none" effect; it is rare that ovulation is "partially" inbibited.
Treatment groups were compared with the control group using a 95% contingency table
or the ED
100 was established with additional dose levels.
Relative Binding Affinities for the Progesterone and Glucocorticoid Receptors
[0084] Uteri and thymus glands were obtained from estradiol-primed immature female rabbits
of the New Zealand White strain for preparation of cytosols for the progesterone and
glucocorticoid receptor assays, respectively. Tissues were excised and immediately
placed in ice cold TEGDM buffer (10 mM Tris, pH 7.4; 1.5 mM EDTA; 10% glycerol vol/vol/;
1 mM dithiothreitol [DTT]; and 20 mM sodium molybdate). The tissues were dissected
free of connective tissue and fat, weighed and minced finely. Minced tissues were
homogenized in 3 volumes TEGDM/gm with four 10 second bursts of a VirTis Cyclone set
at half maximum speed with a 30 second cooling period (in ice) between bursts. Homogenates
were centrifuged at 109,663 g at 4°C for 1 hour to yield the soluble cytosol fraction.
Aliquots of cytosol were snap frozen and stored at -75°C.
[0085] All binding assays were carried out at 2-6°C for 16-18 hours. The following radioactive
ligands were used: [1,2-
3H(N)]-progesterone (50.0 Ci/mmole) for the progesterone receptor (PR). [6,7-
3H(N)-dexamethasone (39.2 Ci/mmole) for the glucocorticoid receptor (GR) and [2,4,6,7-
3H(N)]-estradiol for the estrogen receptor. For the progesterone receptor RBA assays
0.02 ml uterine cytosol or TEDGM buffer, 0.05 ml of various concentrations of test
compounds or progesterone, 0.13 ml TEGDM buffer and 0.05 ml [
3H]-progesterone were added to duplicate tubes. For the glucocorticoid receptor RBA
assays 0.1 ml thymus cytosol or TEDGM buffer, 0.05 ml of various concentrations of
test compounds or dexamethasone, 0.05 ml TBGDM buffer and 0.05 ml [
3H]-dexamethasone were added to duplicate tubes. For the estrogen receptor RBA assays
0.05 ml uterine cytosol, 0.1 ml TEGDM buffer, 0.05 ml of various concentrations of
test compounds or estradiol and 0.05 ml [
3H-estradiol were added to duplicate tubes. The concentrations of the test compounds,
progesterone, dexamethasone and estradiol ranged from 0.05 to 100 nM and the concentrations
of the competitors ranged from 0.5 to 500 nM. Total binding was measured at radioligand
concentrations of 3.5 nM and nonspecific binding was measured in the presence of a
200-fold excess of unlabeled progesterone (PR), dexamethasone (GR) or diethylstilbestrol
(BR), respectively.
[0086] In all incubations bound and free ligand were separated using extra-coated charcoal
(DCC). A 0.1 ml aliquot of DCC (0.5% charcoal/0.05% DextranT-70) was added to each
tube. The tubes were vortexed and incubated on ice for 10 minutes. Five-tenths ml
TEG buffer (without DTT or molybdate) was then added to all tubes to improve supernatant
recovery following centrifugation. The charcoal was pelleted by centrifugation at
2,100 g for 15 minutes at 4°C. The supernatants containing the [
3H]-steroid receptor complexes were decanted into vials containing 4 ml Optifluor (Packard
Instrument Co.), vortexed, equilibrated in a liquid scintillation counter for 30 minutes
and then counted for 2 minutes. This provided the quantity of receptor bound [
3H]-steroid at each competitor concentration.
[0087] The standard curves and the EC
50 (Effective Concentration) for each standard curve and curve for each test compound
was determined by entering the counting data (receptor bound [
3H]-progesterone, [
3H]-dexamethasone or [
3H]-estradiol) into a four parameter sigmoidal computer program (RiaSmart® Immunoassay
Data Reduction Program, Packard Instrument Co., Meriden, Connecticut. The RBA for
each test compound was calculated using the following equation:

where EC
50 Standard = molar concentration of unlabeled progesterone, dexamethasone or estradiol
required to decrease bound [
3H]-progesterone (PR), [
3H]-dexamethasone (GR) or [
3H]-estradiol to 50% of the respective buffer control (100% bound radioligand) and
EC
50 Test Compound = molar concentration of test compound required to decrease bound [
3H]-progesterone (PR), [
3H]-dexamethasone (GR) or [
3H]-estradiol to 50% of the respective buffer control (100% bound radioligand).
RESULTS
EXAMPLE 1
[0088] Since mifepristone (CDB-2477) is frequently used as a reference standard, Table 2,
infra, contains data comparing the antiprogestational activity and relative binding affinity
for the progesterone and glucocorticoid receptors of CDB-2914 with this standard.
Recent studies have shown a good correlation between relative binding affinity for
the glucocorticoid receptor and a biological test based upon the antagonism of dexamethasone-induced
thymus involution in adrenalectomized male rats.
Table 2
| CDB NO. |
COMPOUND NO. |
BINDING AFFINITY1 |
BIOLOGICAL ACTIVITY |
| Progester |
Glucocortic |
antiClauberg2 |
Postcoital3 |
Antiovulator4 |
| 2914 |
69B |
122 (234) |
114 |
100 |
2 |
1 |
| 3875 |
69A |
164 |
30 |
97 |
|
|
| 3247 |
69C |
91 |
49 |
~10 |
2* |
|
| 3248 |
69D |
40 |
89 |
weak (subcu) |
inactive @2* |
|
| 4243 |
91 |
171 |
59 |
inactive |
|
|
| 4418 |
70 |
79 |
/2 |
~25 |
|
|
| 4363 |
71 |
123 (203) |
20 |
253 |
0.5 |
>16 |
| 4399 |
72 |
109 |
110 |
35 |
|
|
| 4176 |
74 |
131 |
32 |
<10 |
|
|
| 4324 |
97a |
120 |
52 |
110 |
|
|
| 4398 |
97b |
47 |
38 |
99 |
|
|
| 4455 |
106a |
|
|
|
|
|
| 4241 |
106b |
136 (172) |
14 |
34 |
|
|
| 4400 |
113A |
117 (237) |
62 |
229 |
|
|
| 4454 |
113B |
59 |
34 |
|
|
|
| 4417 |
113c |
63 |
45 |
70 |
|
|
| 4239 |
123a |
174 (140) |
11 |
45-83 |
|
|
| 4416 |
123b |
64 |
45 |
77 |
|
|
| 4393 |
139 |
30 |
79 |
inactive |
|
|
| 4247 |
126a |
95 |
43 |
170 |
|
|
| 4362 |
126b |
76 |
15 |
125 |
|
|
| 4374 |
126c |
68 |
67 |
224 |
|
|
| 4361 |
129 |
155 |
20 |
303 |
|
|
| 4306 |
133 |
82 |
13 |
95 |
|
|
| 4352 |
138 |
63 |
14 |
57 |
|
|
1Progesterone receptor (estrogen-primed rabbit uterus); progesterone =100% Figure in
() is relative binding affinity of the human isoform A progesterone receptor Glucocorticoid
receptor (estrogen-primed rabbit thymus) dexamethasone = 100%.
2antiClauberg - oral except where indicated; CDB-2914 = 100 (assigned).
3Postcoital - oral, rat MED100 (mg/day) days 0-3 or *days 4-6 subcu; day sperm in vaginal washings = day 0.
4Antiovulatory - oral, rat MED100(mg) single dose at noon on day of proestrus. |
EXAMPLE 2
AntiClauberg
[0089] Data from antiClauberg tests following oral administration are shown in Tables 1
and 2. Compounds
15,
38,
40,
41,
46,
71,
97a,
113a,
126a,
126b,
126c and
129 exhibited greater activity than the standard,
69B. Previous studies have shown that 69B is significantly more potent than mifepristone
(3.27 X; 95% C.I. = 1.41-7.58) in this test. Compounds
15,
38,
71 and
129 represent four of the most potent antiprogestational compounds known, and their low
binding affinity for the glucocorticoid receptor would predict minimal antiglucocorticoid
activity.
Postcoital
[0090] Compound
71 exhibited about four times the postcoital contraceptive activity of the standard,
compound
69B, following oral administration on days 0-3 of gestation.
Antiovulatory
[0091] Compound
71 was not fully active at a dose level 16 times the MED
100 for the standard, compound
69B, and compound
113a exhibited only about 6% of the antiovulatory activity of the standard.
Relative Binding Affinity for the Progesterone and Glucocorticoid Receptors
[0092] Relative binding affinities for the progesterone receptor (estrogen-primed rabbit
uterine cytosol) and glucocorticoid receptor (estrogen-primed rabbit thymic cytosol)
are shown in Table 1. Several compounds were also tested for binding affinity for
the human isoform A progesterone receptor. Compounds
12,
13,
14A,
14B,
15,
28,
38,
69A,
91,
71,
71,
73,
97a,
106b,
113a,
113d,
122b and
129 showed binding affinities greater than that observed for the standard, compound
69B. On the other hand, most of the compounds tested exhibited reduced binding affinity
for both the progesterone and the glucocorticoid receptor.
DISCUSSION
[0093] Many members of a series of derivatives of 19-norprogesterone possess potent antiprogestational
activity following oral administration in experimental animals. They exhibit high
binding affinity for the progesterone receptor (rabbit uterine) and only modest relative
binding affinity for the glucocorticoid receptor (rabbit thymus). This is reflected
in standard antiprogestational assays showing strong inhibition of progesterone-induced
alterations of rabbit uterine endometrium. It is anticipated that the reduced binding
affinity for the glucocorticoid receptor will reflect diminished biological antiglucocorticoid
activity.