United States Patent [191
`Barrie et al.
`
`lllllllllllllllllllllllllllllllllllllIlllllllllllllllllllllllllllllllllllll
`5,604,213
`Feb. 18, 1997
`
`[11] Patent Number:
`[45] Date of Patent:
`
`US005604213A
`
`[54] 17-SUBSTITUTED STEROIDS USEFUL IN
`CANCER TREATMENT
`
`[75] Inventors: Susan E. Barrie, Kent; Michael
`Jarmau, London; Gerard A. Potter,
`Cheshire; Ian R. Hardcastle, Sutton,
`all of Great Britain
`
`[73] Assignee: British Technology Group Limited,
`London, England
`
`[21] Appl. N0.: 315,882
`[22] Filed:
`Sep. 30, 1994
`
`Related US. Application Data
`
`[63] Continuation-impart of PCT/GB93/O053l May. 15, 1993.
`[30]
`Foreign Application Priority Data
`
`Mar. 31, 1992 [GB]
`Nov. 27, 1992 [GB]
`Sep. 30, 1993 [GB]
`Jul. 14, 1994 [GB]
`
`United Kingdom ................. .. 9207057
`United Kingdom
`..
`United Kingdom
`United Kingdom
`
`9414192
`
`[51] Int. Cl.6 ........................... .. A61K 31158; C071 43/00
`[52]
`............ .. 514/176; 540/95
`[58] Field of Search .............................. .. 540/95; 514/176
`
`[56]
`
`References Cited
`
`FOREIGN PATENT DOCUMENTS
`
`288053 10/1988 European Pat. 01f. .
`413270 2/1991 European Pat. OE. .
`
`OTHER PUBLICATIONS
`
`M-J. Shiao,~“New synthesis of Azabufalin from C-l7
`Steroidal Ketones”, J. Org. Chem. 47, 5189-5191 (1982).
`B. F. Hoifman, “The pharmacology of cardiac glycosides” in
`Cardiac therapy, ed. M. R. Rosen and B. F. Hoffman,
`Martinus Nijhoff Publishers (1983), Chapter 11, pp.
`387-412.
`R. Thomas et al., “Synthesis and Biological Activity of
`Semisynthetic Digitalis Analogs”, J. Pharm. Sci. 63,
`1649-1683 (1974).
`T. Shigei and S. Mineshita, “Cardiotonic activities of four
`new compounds .
`.
`. ”, Experientia 24, 466-467 (1968).
`T. Shigei et al., “Structure-Activity Relationship of the
`Cardenolide .
`.
`. ”, Experientia 29, 449-450 (1973).
`3
`M. Okada and Y.
`Saito,
`“Synthesis
`of
`B-Hydroxy-Sot-card-ZO
`2)
`enolide
`(14-Deoxy-14B-uzarigenin)”, Chem. Pharm. Bull. 16,
`2223-2227 (1968).
`B. K. Naidoo et al., “Cardiotonic Steroids I: Importance of
`14B-Hydroxy Group in Digitoxigenin” J. Pharm. Sci. 63,
`1391-1394 (1974).
`W. Schonfeld and K. R. H. Repke, “A Free-Wilson Analysis
`of 5B, l4B-Androstane Derivatives Inhibiting the Na/K-AT
`Pase from Human Heart”, Quant. Struct.—-Act. Relat. 7,
`160-165 (1988).
`T. Hashimoto et al., “Studies on Digitalis Glycosides XXXV
`.
`.
`. ”, Chem. Pharm. Bull. 27, 2975-2979 (1979).
`K-O. Haustein et al., “Structure-Activity Relationships of
`Natural and Semi-Synthetic Genius and Glycosides .
`.
`. ”,
`Pharmacology 10, 65-75 (1973).
`
`Th. W. Giintert and H. H. A. Linde, “Cardiac glycosides:
`Prerequisites for the development of new cardiotonic com
`pounds”, Experientia, 33, 698-703 (1977).
`J. Wicha et al.
`‘Synthesis of l7.beta.-Pyridyl-and
`17.beta-Pyridyl-androstane Derivatives’. Heterocycles. vol.
`16, No. 4, 1981, pp. 521-524.
`J. Wicha et al. ‘Synthesis and Molecular Biological Activity
`of the Pyridine Analog of Cardiotonic Steroids’. Hetero
`cycles. vol. 20, No. 2, 1983, pp. 231-234.
`G. A. Potter et al., “Discovery of Highly Potent and Selec
`tive Enzyme Inhibitors .
`.
`. ” Poster presented at the
`SmithKline Beecham Research Symposium, Robinson Col
`lege, Cambridge, England, 25-26 Mar. 1993.
`S. E. Barrie et al., “Highly Potent Inhibitors of Human
`Cytochrome P-450 (170a) .
`.
`. ” Poster presented at the
`British Association for Cancer Research meeting in Shef
`?eld, England, 28-31 Mar. 1993.
`G. A. Potter et al., “Highly Potent Inhibitors of Human
`Cytrochrome P-450 (l7ot) . . . ”, Poster presented at the third
`Drug Discovery and Development Symposium, San Diego,
`California, USA, 22-24 Jul. 1993.
`B. Schweder et al., “Synthesis des A16, 17-Iodids Und—
`Tn'?ats von Androsta-4-en-3, 17-dion .
`.
`. ”, J. Prakt.
`Chem. 335, 201-204 (1993).
`D. H. R. Barton et al., “An Improved Preparation of Vinyl
`Iodides”, Tetrahedron letters 24, 1605-1608 (1983).
`
`(List continued on next page.)
`
`Primary Examiner—Mukund J. Shah
`Assistant Examiner—Anthony Bottino
`Attorney, Agent, or Firm—NiXon & Vanderhye
`
`ABSTRACT
`[57]
`Compounds of the general formula (1)
`
`14 RRlS
`R15
`wherein X represents the residue of the A, B and C rings of
`a steroid, R represents a hydrogen atom or an alkyl group of
`l to 4 carbon atoms, R14 represents a hydrogen atom and R15
`represents a hydrogen atom or an alkyl or alkoxy group of
`l-4 carbon atoms, or a hydroxy or alkylcarbonyloxy group
`of 2 to 5 carbon atoms or R14 and R15 together represent a
`double bond, and R16 represents a hydrogen atom or an alkyl
`group of 1 to 4 carbon atoms, in the form of the free bases
`or phannaceutically acceptable acid addition salts, are useful
`for treatment of androgen-dependent disorders, especially
`prostatic cancer, and also oestrogen-dependent disorders
`such as breast cancer.
`
`22 Claims, No Drawings
`
`MYLAN PHARMS. INC. EXHIBIT 1005 PAGE 1
`
`

`
`5,604,213
`Page 2
`
`OTHER PUBLICATIQNS
`
`D. H. R. Barton et al., “Studies on the oxidation of Hydra
`zones with iodide .
`.
`. ”, Tetrahedron 44, 147-162 (1988).
`J. Wicha et a1. ‘Cardiotonic Steroids. Part 8. Synthesis of
`17.beta.
`(3'pyridyl)—l4.beta.—Androst—4-ene—3.beta.l4—diol from
`17-Oxoandrostane Derivatives’ Bulletin of the Polish Acad
`
`emy of Sciences. Chemistry. vol. 33, No. 1-2, 1985, pp.
`19—27.
`
`J. Wicha et a1. ‘Cardiotonic Steroids. Part 7. Synthesis of
`17.beta~Pyridy1-andr0stane Derivatives’. Bulletin of the
`Polish Academy of Sciences. Chemistry. vol. 32, No. 1~2,
`1984, pp. 75-83.
`
`MYLAN PHARMS. INC. EXHIBIT 1005 PAGE 2
`
`

`
`5,604,213
`
`1
`17-SUBSTITUTED STEROIDS USEFUL IN
`CANCER TREATIVIENT
`
`This speci?cation is a continuation-in-part of PCT Appli
`cation PCT/GB93/0O531, ?led Mar. 15, 1993 and which
`designated the United States of America.
`
`BACKGROUND THE INVENTION
`
`1. Field of the Invention
`This invention relates to l7-substituted steroids and their
`use in the treatment of androgen-dependent and oestrogen
`dependent disorders, especially prostatic cancer and breast
`cancer respectively.
`2. Description of the Related Art
`The l70t-hydroxylase/C17_20 lyase enzyme complex
`(hereinafter “hydroxylase/lyase”) is known to be essential
`for the biosynthesis of androgens and oestrogens. In the
`treatment of androgen~dependent disorders, especially pro
`static cancer, there is a need for strong inhibitors of hydroxy
`lase/lyase. Certain anti-androgenic steroids are well known,
`for example Cyproterone acetate (17a-acetoxy-6-chloro-l0t,
`2ot~methylene-4,6-pregnadiene-3,20-dione). Many other
`steroids have been tested as hydroxylase/lyase inhibitors.
`See, for example, PCT Speci?cation WO 92/00992 (Scher
`ing AG) which describes anti-androgenic steroids having a
`pyrazole or triazole ring fused to the A ring at the 2,3
`position, or European Speci?cations EP-A 288053 and EP-A
`413270 (Merrell Dow) which propose 17B-cyclopropy
`lamino androst-S-en-BB-ol or -4-en-3-one and their deriva
`tives.
`
`SUMMARY OF THE INVENTION
`
`It has now surprisingly been found that steroids lacking a
`C20 side chain and having a l7-(3-pyridyl) ring in its place,
`together with a 16,17-double bond, are powerful hydroxy
`lase/lyase inhibitors, useful for the above-stated purposes.
`According to the invention, there are provided com
`pounds of the general formula
`
`10
`
`15
`
`25
`
`35
`
`40
`
`R
`
`(I)
`
`45
`
`Xl
`
`R15
`
`R14
`R15
`
`15
`R
`
`wherein X represents the residue of the A, B and C rings
`of asteroid, R represents a hydrogen atom or an alkyl
`group of 1-4 carbon atoms, R14 represents a hydrogen
`atom, a halogen atom or an alkyl group of 1 to 4 carbon
`atoms and each of the R15 substituents independently
`represents a hydrogen atom or an alkyl or alkoxy group
`of l-4 carbon atoms, a hydroxy group or an alkylcar
`bonyloxy group of 2 to 5 carbon atoms or together
`represent an 0x0 or methylene group or R14 and one of
`the R15 groups together represent a double bond and the
`other R15 group represents a hydrogen atom or an alkyl
`group of 1 to 4 carbon atoms, and R1‘5 represents a
`hydrogen atom, halogen atom, or an alkyl group of 1 to
`
`55
`
`60
`
`65
`
`2
`4 carbon atoms, in the form of the free bases or
`pharmaceutically acceptable acid addition salts.
`The term “steroid” herein includes any compound having
`the steroidal B and C rings, but in which all or part of the A
`ring is missing e.g. ring not closed (lacking the 2- or
`3-position C-atom or both) or takes the form of a cyclopen
`tane ring. It also includes azasteroids having a ring nitrogen
`atom in place of a ring carbon atom, especially in the A-ring
`such as in 4-azasteroids.
`In general, the compounds of formula (1) are new and
`such compounds per se are included in the invention.
`However, certain of them have been disclosed as interme
`diates in the synthesis of certain steroids having a 3~pyridyl
`or 3-pyridonyl group in the 17B-position, see J. Wicha and
`M. Masnyk, Bulletin of the Polish Academy of Sciences:
`Chemistry 33 (1—2), 19-27 and 29—37 (1985). The ?rst of
`these papers says that a 17B-side chain of the form
`—C=C—-C=O or —C=C—C=N favours cardiotonic
`properties and describes the synthesis of 17B-(3-pyridyl)
`l4B-androst-4-ene-3B,14-diol, while the second uses this
`compound to prepare 17B-[3-pyrid-2(1H)onyl]-14[3-an
`drost-4-ene-3B,l4-diol. Those ?nal compounds differ from
`those of the present invention by having a saturated D-ting
`and the paper contains no test results. Insofar as certain
`compounds within formula (1) are known as intermediates
`in these syntheses, the invention extends to the compounds
`only for use in therapy. These are 3B-acetoxy~l7-(3-pyridy
`l)androsta-5,l4,l6-triene and 3B,150t~ and 3B,l5B-diac
`etoxy-l7-(3-pyridyl)androsta-5,l6-diene. See also J. Wicha.
`et. al., Heterocycles 20, 231~234 (1983 ) which is a pre
`liminary communication of the ?rst of the above two papers.
`J. Wicha et. al., Bulletin of the Polish Academy of
`Sciences, Chemistry 32 (l—2), 75-83 (1984) have also
`described the preparation of 3B-methoxy-17B-(3-pyridyl)an
`drostane and pyridone analogues thereof via the intermedi
`ate SB-methoxy-17-(3-pyridyl)-5ot-androst-16-ene. Accord
`ingly, the invention extends to the latter compound only for
`use in therapy. A preliminary communication of this paper,
`by J. Wicha and M. Masynk, appeared in Heterocycles 16,
`521-524 (1981).
`The invention also includes pharmaceutical compositions
`comprising a compound of formula (1) in association with a
`pharmaceutically acceptable diluent or carrier. The termi
`nology “pharmaceutical compositions” implies that
`injectible formulations are sterile and pyrogen-free and
`thereby excludes any compositions comprising the com
`pound of formula (1) and a non-sterile organic solvent, such
`as may be encountered in the context of the ?nal stages of
`preparing these above-mentioned compounds of formula (1)
`which have been described in the literature but without any
`therapeutic use being mentioned.
`
`DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`
`In the compounds of the invention the essential structural
`features comprise all of:
`a 3-pyridyl ring in the 17-position
`a ring double bond in the 16,17-position of the D-ring
`the 18-position methyl group
`It is critical that the pyridine nitrogen atom be in the
`3-position, not the 2- or 4-p0sition. It is also critical that the
`pyridine ring be joined directly to the l7-carbon atom. This
`criticality is demonstrated by tests of inhibiting activity
`against hydroxylase and lyase (Table 1). The concentration
`of test compound required to achieve 50% inhibition of the
`
`MYLAN PHARMS. INC. EXHIBIT 1005 PAGE 3
`
`

`
`5,604,213
`
`3
`enzyme is far greater for the 2-pyridyl, 4-pyridyl and 2-py
`ridylmethyl compounds tested than for the 3-pyridyl. The
`methods of determination were as described in the Examples
`hereinafter.
`
`TABLE 1
`
`Effect of variations in the l7asubstitutent on inhibition of
`hydroxylasc and lyase, demonstrating the criticality of the
`l7-substituent in this invention.
`
`4
`in the above»cited Speci?cation WO 92/00992, or oxazole
`ring fused in the same positions.
`By way of example, X can represent the residue of
`androstan-3ot- or 3B—ol,
`androst-5-en-3ot- or 35-01,
`androst—4'en—3-one,
`androst~2~ene,
`androst-4-ene,
`androst~5-ene,
`androsta-5,7—dien-3ot or 313-01,
`androsta-1,4-dien-3-one,
`androsta-3,5-diene,
`estra-l,3,5[l0]-triene, ‘
`estra-1,3,5[10]-trien-3-ol,
`5ot-androstan-3~one,
`androst-4-ene-3,1l-dione,
`6-?uoroandrost-4-ene-3-one or
`androstan-4-ene-3,6-dione
`each of which, where structurally permissible, can be further
`derivatised in one or more of the following ways:
`to form 3-esters, especially 3-alkanoates and -benzoates,
`to have one or more carbon to carbon ring double bonds
`in any of the 5,6-, 6,7-7,8-, 9,11- and 11,12-positions
`as 3~oximes
`as 3-methylenes
`as 3-carboxylates
`as 3~nit1iles
`as 3-nitros
`as 3~desoxy derivatives
`to have one or more hydroxy, halo, C1_4-alkyl, tri?uo
`romethyl, C1_4-alkoxy, C1_4-alkanoyloxy, benzoyloxy,
`oxo, methylene or alkenyl substituents in the A, B or
`C-ring
`to be 19-nor.
`Preferred C1_4~a1kyl and alkoxy groups are methyl and
`ethoxy.
`Preferred C1_4»alkanoyloxy groups are acetoxy and pro
`panoyloxy.
`Preferred halo groups are ?uoro, bromo and chloro and
`the preferred substitution position is the 6-position.
`The substituents include, for instance, 2-?uoro, 4-?uoro,
`6-?uoro, 9-?uoro, 3-tri?uoromethyl, 6-methyl, 7-methyl,
`6-oxo, 7-0xo, ll-oxo, 6-methylene, ll-methylene, 4-hy
`droxy, 7-hydroxy, 11~hydroxy or l2-hydroxy, each in any
`appropriate epimeric form, and, subject to structural com
`patibility (well known in general steroid chemistry), in any
`combination of two or more such groups.
`Compounds which are likely to be unstable are considered
`excluded from consideration. Such compounds will be evi
`dent to steroid chemists. Compounds having esoteric sub
`stituents likely to interfere with the stereochernical align
`ment of the steroid molecule with the enzymes to be
`inhibited, by virtue of steric or electronic distribution effects,
`are to be avoided. For example, a 2,3,5,6-tetra?uoro-4
`tri?uoromethylphenoxy substituent in the 3-position is not
`recommended. Androst-5-en-3B-ol having such an ether
`substituent in place of the 3B-hydroxy group has been shown
`to be a very poor inhibitor for lyase and hydroxylase.
`The currently preferred compounds of formula (1) include
`those which are saturated and unsubstituted at the 11~ and
`12-positions and which therefore are of the general formula
`(3):
`
`10
`
`(2)
`
`R17
`17
`
`16
`
`IC5o(l1M)
`
`Lyase
`
`Hydroylase
`
`0.13
`
`0.32
`
`HO
`
`Rn
`
`Type
`
`/ \
`
`2-Pyridy1
`(for comparison)
`
`" N
`
`\
`
`N
`
`'d 1
`3-
`Pyn Y
`(present invention)
`
`0.003
`
`0.004
`
`4-pyridyl
`(for comparison)
`
`2.0
`
`5.0
`
`2-picolyl
`/ \ (for comparison)
`
`>10
`
`>10
`
`Note:
`all the compounds of formula (2) tested were poor inhibitors of aromatase:
`1c,o >20 “M.
`Our modelling of the geometry of the putative transition
`state of the lyase component of the hydroxylase-lyase
`enzyme complex, in the putative mechanism of action of the
`lyase component, suggests that the 16,17—double bond is
`essential to allow the 3-pyn'dine ring to adopt the orientation
`required for co-ordination to the haem group of the hydroxy
`lase-lyase complex.
`Elsewhere, the D-ring can have any other simple substitu~
`ent. Certain simple substituents are de?ned in connection
`with the preferred general formula (1), but it will be appre
`ciated that others could be substituted for those of formula
`(1). In the compounds of formula (1), R15 is preferably
`hydrogen or alkyl of 1 to 3 carbon atoms, R16 hydrogen,
`alkyl of l to 3 carbon atoms, ?uorine, chlorine, bromine or
`iodine, and R hydrogen or methyl, in the 5-position of the
`pyridine ring.
`The remainder of the molecule, designated “X” in formula
`(1), can be of any kind conventional in steroid chemistry or
`have any other feature known in steroids having anti
`androgenic activity, for example the pyrazole or triazole
`ring, fused to the A ring at the 2- and 3- positions, disclosed
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`65
`
`MYLAN PHARMS. INC. EXHIBIT 1005 PAGE 4
`
`

`
`5,604,213
`
`(3)
`
`6
`carbon atoms, most preferably ethyl or methoxy, or Z1 and
`Z2 together represent an alkylenedioxy group of 2 or 3
`carbon atoms and R is as de?ned above and carrying out said
`cross-coupling reaction.
`The palladium complex-catalysed cross-coupling reaction
`of the l7-substituted steroid with the boron compound is
`believed to involve the steps indicated in the following
`illustrative reaction scheme 1 (Py=3-pyridyl). The pyridyl
`anionic species is provided by the boron compound.
`
`15
`
`25
`
`30
`
`The replacement of the 17-enol group can be, for
`example, to form a l6,l7»ene tri?uoromethanesulphonate
`(“tri?ate”) of formula (6):
`
`O- SO2CF3
`
`(6)
`
`X {
`
`R16
`
`R14
`R15
`
`15
`R
`
`or a 17-iodo or bromo-16,[17]-ene (a “vinyl halide”) of
`formula (7):
`
`(7)
`
`R14
`R15
`
`R15
`
`(Hal:I or Br)
`Compounds of formula (6) can be prepared by reacting
`the 17-oxo compound of formula (4) with an enol ester
`forrning tri?uoromethanesulphonic acid derivative such as
`the anhydride, see S. Cacchi, E. Morera and G. Ortar,
`Tetrahedron Letters, 25, 4821 (1984). The 17-oxo compound
`can be considered notionally to exist in the enol form, the
`reaction being one of esteri?cation of the enol.
`For the preparation of the 17-position derivatives of
`formula (6) or (7) any necessary protection of other groups
`in the molecule may be ?rst carried out. For example in the
`tri?ate route hydroxyl groups are conveniently protected as
`their acetates, whilst in the vinyl halide route the 3-oxo
`group of steroids can be selectively protected as their
`per?uorotolyl enol ethers, see M. Jarman and R. McCague,
`J.Chem. Soc. Perkin Trans. 1, 1129 (1987).
`
`wherein Q represents the residue of A, B and C rings of
`asteroid, and R is a hydrogen atom or an alkyl group of 1—4
`carbon atoms.
`However, 11- and/or 12-substituted compounds are also
`active. Particularly preferred are ll-oxo and llB-hydroxy
`derivatives of compounds of formula (3).
`Speci?cally preferred compounds of the invention com
`prise
`17-(3-pyridyl)androsta-5,16-dien-3B-ol,
`l7-(3-pyridyl)androsta-3,5,16-triene,
`17-(3-pyridyl)androsta-4,16—dien-3-one,
`17-(3-pyridyl)estra-l,3,5[10],16-tetraen-3-ol,
`17-(3-pyridyD-Sa-androst-16-en-30t-ol
`and their acid addition salts and 3-esters.
`Other notable compounds of the invention comprise
`17-(3-pyridyl)-5(x~androst-16-en-3-one,
`17- (3 -pyridyl)-androsta-4, 1 6-diene-3, 1 l -dione,
`17-(3~pyridyl)-androsta-3,5,l6-trien-3-ol,
`60t- and GB-?uoro-17-(3-pyridyl)androsta-4,l6-dien-3-one
`l7-(3-pyridyl)androsta-4,16-dien-3,6-dione,
`17~[3-(5-methyl pyridyl)]androsta-5,16 dien-3B-ol
`Sot-tri?uoromethyl-17-(3-pyridyl)androsta-16-en-3B-ol
`and their acid addition salts and 3-esters.
`Insofar as certain compounds within formula (1) are
`known per se and these are compounds which are less easy
`to prepare than many of the others, a preferred class of
`compounds of formula (1) is those which do not have a
`3|3-alkoxy group, a 14,15-double bond or a 15-ester group.
`The compounds of formula (1) can be prepared by a
`method which is in itself novel and inventive. Starting from
`a 17-oxo compound of general formula (4):
`(T
`
`35
`
`40
`
`(4)
`
`45
`
`50
`
`R16
`
`R14
`
`wherein X, R“, R15 and R16 are as de?ned above and any
`other oxo groups and hydroxy groups in the molecule are
`?rst appropriately protected, the method comprises replac
`ing the 17-hydroxy group of compound (4) in its enol form
`by a leaving group (L) which is capable of being replaced by
`a 3-pyridyl group in a palladium complex-catalysed cross
`coupling reaction with a pyridyl ring-substituted boron
`compound of formula (5):
`
`R
`
`/ \ N
`
`(5)
`
`B2121
`wherein Z1 and Z2 independently represent hydroxy or
`alkoxy or alkyl of 1-4 carbon atoms each, preferably 1-3
`
`65
`
`MYLAN PHARMS. INC. EXHIBIT 1005 PAGE 5
`
`

`
`5,604,213
`
`8
`-continued
`Scheme 2
`
`7
`Compounds of formula (7) can be prepared by ?rst
`hydrazinating the 17-oxo compounds of formula (4) by a
`standard method to form the 17-hydrazone, which is then
`reacted with bromine or iodine in the presence of an amine
`or guanidine base, see D. Barton, G. Bashiardes and J.
`Fourrny, Tetrahedron Letters, 24, 1605 (1983).
`The l7~position derivative (whether tri?ate or vinyl
`halide) is then reacted with the boron compound of formula
`(5) using as catalyst a palladium(0) phosphine complex, for
`example tetrakis(triphenylphosphine)palladium(0), or a pal
`ladium (II) phosphine complex which is reducible in situ to
`a palladium(0) phosphine species, especially bis(tn'ph
`enylphosphine)palladium (ll) chloride.
`
`SUMMARY OF THE INVENTION
`
`The vinyl halide route, via a compound of formula (7), is
`particularly well suited to the preparation of 3B—acyloxy-16,
`17-ene-17-(3-pyridyl) steroids, especially the preferred
`compound, 3B-acetoxy-17-(3-pyridyl)androsta-5,16-diene,
`of formula (8):
`
`/ \
`
`N
`
`(8)
`
`LA
`
`10
`
`20
`
`25
`
`35
`
`AcO
`
`but using the unprotected 3B-hydroxy compound as starting
`material. By‘products can be reduced either (a) by keeping
`the proportion of organoboron compound (borane) used in
`the cross~coupling reaction within the range 1.0 to 1.2
`equivalents per equivalent of steroid or (b) by crystallising
`the reaction product of the cross-coupling reaction from a
`mixture of acetonitrile and methanol. This route via the vinyl
`iodide intermediate is therefore amenable to large scale
`synthesis, and is shown in Scheme 2 below.
`
`45
`
`50
`
`Scheme 2
`
`/ O
`
`/ N-NI-Iz
`
`55
`
`X {
`
`R Standard method
`X [
`R
`16 € 16
`(unspeci?ed)
`
`R14
`R15
`
`15
`R
`
`R14
`R15
`
`'
`
`15
`R
`
`12 or Brzl
`amine or
`guanidine base
`(lit. ref. given)
`
`60
`
`65
`
`Hal
`
`R16
`
`R14
`R15
`
`15
`R
`
`(Hal : I or Br)
`
`BBZlZZ/
`Palladium (O) —
`Ph3P complex
`e.g. from PdCl2(Ph3P)2
`
`The principle of this aspect of the invention may be
`expressed as a method of preparing a BB-hydroxy- or
`3B<(lower
`acyloxy)-l6,17-ene-17-(3-pyridyl)-substituted
`steroid, wherein the 3B-(lower acyloxy) group of the steroid
`has from 2 to 4 carbon atoms, which comprises subjecting
`a SB-hydroxy-l6,17-ene-17-iodo or-bromo steroid to a pal—
`ladium complex-catalysed cross~coupling reaction with a
`(3-pyridyl)-substituted borane, in which the pyridine ring is
`substituted at the 5-position by an alkyl group of 1 to 4
`carbon atoms or is unsubstituted thereat, especially with a
`said borane of formula (5), wherein R is a hydrogen atom or
`an alkyl group of 1—4 carbon atoms and Z1 and Z2 inde
`pendently represent hydroxy or alkoxy or alkyl or l-3
`carbon atoms each or Z1 and Z2 together represent an
`alkylenedioxy group of 2 or 3 carbon atoms, in a proportion
`of at least 1.0 equivalent of boron compound per equivalent
`of steroid, in an organic liquid, which is a solvent for the
`3B-hydroxy steroidal reaction product, and optionally esteri
`fying the BIB-hydroxy reaction product to the 3B-acyloxy
`ester, which method comprises feature (a) or (b) above.
`Preferably the vinyl iodide or bromide is unsubstituted in
`the 14, 15 and l6-positions, in which case it can be prepared
`from dehydroepiandrosterone (DHEA). In the hydrazination
`it is preferable to use hydrazine hydrate together with a
`catalytic amount of a proton provider which is most pref
`erably hydrazine sulfate.
`The hydrazone is preferably iodinated with iodine or
`brorninated with bromine in the presence of a strong base
`such as a tetraalkylguanidine, especially tetrarnethylguand
`ine which is cheaply and readily available.
`In the cross-coupling reaction, the boron compound is
`preferably a diethylborane or a dimethoxyborane (Z1=Z2=Et
`or OMe). Other boranes include those in which the boron
`atom is part of a cyclic ether ring e.g. as in Z, Z2=l,2
`ethylenedioxy or 1,3-propylenedioxy. In embodiment (a) of
`this aspect of the invention the proportion of borane added
`is at least 1.0, but no more than 1.2 equivalents of boron per
`equivalent of steroid, preferably about 1.1, but in the
`embodiment (b) a higher proportion is preferred, e.g. from
`1.2:1 to 1.5 :1 equivalents of boron compound to steroid. The
`higher proportion will give the better yield of product but
`also more of the contaminating boron, phosphine and/or
`palladium compounds. According to embodiment (b), how
`ever, these are removed with the acetonitrile solvent. In
`either embodiment, the palladium compound is a palladium
`(O) phosphine complex such as tetrakis(triphenylphosphine)
`palladium (0) or a compound reducible to a palladium (0)
`
`MYLAN PHARMS. INC. EXHIBIT 1005 PAGE 6
`
`

`
`5,604,213
`
`9
`phosphine species, especially bis(triphenylphosphine) pal
`ladium (II) chloride. The reaction vessel is preferably purged
`with an inert gas, especially argon or nitrogen, to minimise
`the possibility of oxidation with a corresponding redox
`reduction of palladium to the metallic state.
`The cross-coupling reaction is preferably carried out in
`two phases, one aqueous, one organic. The organic phase
`comprises an organic solvent for the 3B-hydroxy steroidal
`reaction product, especially tetrahydrofuran (THF). Other
`cyclic ethers such as dioxane could be used in place of THF.
`Preferably, a nucleophilic activator, such as sodium carbon
`ate, is used, in which case it is normally present in the
`aqueous phase.
`After the reaction, inorganic salts can be removed by ?rst
`adding another organic solvent, preferably diethyl ether,
`which is a solvent for the organoboron contaminants pro
`duced in the reaction product, and miscible with the ?rst
`mentioned organic solvent (e.g. THF), but immiscible with
`water, whereafter the organic, e.g. THF-diethyl ether, phase
`and water (aqueous phase) can be separated. After this
`separation, various work-up procedures are operable. In one
`20
`procedure, particularly suited to embodiment (a), the THF
`and diethyl ether are removed, e.g. evaporated as a mixture,
`and the remaining reaction product is washed with a third
`organic solvent, which can be diethyl ether, preferably
`cooled to below room temperature, most especially to 10° C.
`or lower. The third organic solvent is one in which the
`3B-hydroxy steroid reaction product has a low solubility and
`which, importantly, removes the organoboron compound/s
`(and also the contaminating phosphine and palladium com
`pound/s). Diethyl ether is preferred.
`A different work-up procedure, used in embodiment (b),
`comprises crystallisation from acetonitn'le/methanol. Aceto
`nitrile is a preferred crystallisation solvent to keep boron
`compound as well as palladium compound in solution and is
`therefore used in an excess over methanol e.g. an excess of
`at least 5:1 and preferably about 8:1 by volume.
`To prepare the 3B-acyloxy (alkylcarbonyloxy) com
`pounds, of which the acetoxy compound is preferred, stan
`dard acylating (acyl-esten'?cation) agents such as acetyl,
`propionyl or butyryl chloride or anhydride can be used. The
`?nal esteri?cation product may be crystallised direct from
`hexane, rather than from ethanol/water followed by hexane.
`Preferably, the work-up procedure comprises reverse phase
`chromatography, i.e. using a relatively lipophilic solid
`phase. In this procedure, the chief by-product, a bis-steroidal
`compound, is preferentially retained on the solid phase and
`can be eluted with a good separation from the desired
`product. 7
`Further compounds of the invention can be prepared by
`standard steroid to steroid inter-conversion chemistry, so
`long as the D-ring chemical structure is not affected thereby.
`If the D-ring structure is likely to be affected, it would
`usually be necessary to prepare the desired compound de
`novo, i.e. by choosing the appropriate starting compound of
`formula (4), protected if necessary, and carrying out the
`reactions of l7-substitution of the enol and cross-coupling
`with the boron compound as described above.
`By way of example, the 3-esters of asteroid 3-01 with an
`alkanoic acid of l to 6 carbon atoms, or a cycloalkanoic acid
`or aralkanoic acid such as phenylacetic or phenylpropionic
`acid, an aroic acid such as benzoic acid, or other simple
`organic acid such as methanesulphonic acid, can be con
`verted into the 3-01 or the 3-01 to the 3-ester. Other examples
`of simple conversions which would not affect the D-ring
`structure are
`i) Oppenauer oxidation using cyclohexanone and aluminium
`isopropoxide to convert 3-hydroxy to 3-oxo steroids and
`notably A5‘6-3-hydroxy to A4'5-3-oxo steroids;
`
`55
`
`60
`
`65
`
`25
`
`30
`
`35
`
`45
`
`50
`
`10
`ii) Wittig ole?nation to convert oxo groups to methylene
`groups [D. D. Evans et al., J. Chem. Soc., 4312-4317,
`(1963)];
`iii) Oxidation of A5-3B-hydroxy to A4-3,6~dione steroids
`using N-methylmorpholine N-oxide and tetra-n-propy
`lamrnonium perruthenate catalyst [M. Moreno et al.,
`Tetrahedron Letters, 32, 3201-3204, (1991)];
`iv) 6-Methylenation of A4-3-oxo steroids using formalde
`hyde dimethylacetal [K. Annen et al., Synthesis, 34-40
`(1982)];
`.
`v) Conversion of A4~3—oxo to 4,4-dimethyl-A5-3-oxo, A1’4
`3-oxo, A1*4’6-3-oxo, 7ot-methyl-A4-3-oxo, A4'6-3-oxo,
`6-chloro-A-4*6-3-oxo, A2’4-2,3lisoxazole, 6ot-methyl-A4
`3-oxo and A4—3-desoxy; A5-3B-ol to 5ot-?uoro-6-oxo,
`5a,6,6-tri?uoro, 6,6-di?uoro and 6ot-?uoro-A4-3-oxo;
`and ll-oxo to ll-hydroxy and A9'“ steroids [D. Lednicer
`and L. A. Mitscher, The Organic Chemistry of Drug
`Synthesis, ls. 2 and 3, Wiley (1980 and 1984)] or
`vi) Electrophilic ?uorination of steroids using N-?uoropy
`ridinium reagents [T. Umenoto et al., Organic Synthesis
`69, 129-143 (1990)].
`The compounds of formula (1) may be prepared as salts,
`e.g. the hydrochloride and converted to the free base form
`and thereafter to such other conventional pharmaceutically
`acceptable salts as acetates, citrates and lactates, as may
`seem appropriate.
`The present invention also provides a pharmaceutical
`composition which comprises a therapeutically effective
`amount of a compound of the invention, in association with
`a therapeutically acceptable carrier or diluent. The compo
`sition of the invention can, for example, be in a form suitable
`for parenteral (e.g. intravenous, intramuscular or intracavi
`tal), oral, topical or rectal administration. Particular forms of
`the composition may be, for example, solutions, suspen
`sions, emulsions, creams, tablets, capsules, lipsomes or
`micro-reservoirs, especially compositions in orally ingest
`ible or sterile injectable form. The preferred form of com
`position contemplated is the dry solid form, which includes
`capsules, granules, tablets, pills, boluses and powders. The
`solid carrier may comprise one or more excipients, e.g.
`lactose, ?llers, disintegrating agents, binders, e.g. cellulose,
`carboxymethylcellulose or starch or anti-stick agents, e.g.
`magnesium stearate, to prevent tablets from adhering to
`tabletting equipment. Tablets, pills and boluses may be
`formed so as to disintegrate rapidly or to provide slow
`release of the active ingredient.
`The present invention also includes a method of treating
`androgen- and oestrogen-dependent disorders, especially
`tumours, and most especially pro static tumours, in the
`mammalian body, which comprises administering a com
`pound of the invention to a mammalian patient in a thera
`peutically effective dose, e.g. in the range 0.001—0.04
`mmole/kg body weight, preferably 0.001—0.0l mmole/kg,
`administered daily or twice daily during the course of
`treatment. This works out (for humans) at 20-800 mg/pa
`tient per day. The preferred use is in treating prostatic cancer.
`Another use is in treating breast cancer.
`The following Examples illustrate the invention.
`
`EXAMPLE 1
`(a) 3B-Acetoxyandrosta—5,l6-dien-17-yl tn'?uoromethane
`sulphonate
`To a stirred solution of dehydroepiandrosterone-3-acetate
`(24.8 g, 75 nunol) in dry dichloromethane (500 ml) con
`taining 2,6-di-t-butyl-4-methylpyridine (18.5 g, 90 mmol)
`was added tn'?uoromethanesulphonic anhydride (12.6 ml,
`
`MYLAN PHARMS. INC. EXHIBIT 1005 PAGE 7
`
`

`
`5,604,213
`
`11
`75 mmol). After 12 h the mixture was ?ltered and washed
`with water (50 ml), dried (MgSO4), arid the solvent evapo
`rated. Chromatography, on elution with light petroleum
`dichloromethane (6:1), gave ?rstly androsta-3,5,16-trien-l7
`yl tri?uoromethanesulphonate (3.02 g, 10%) as an oil.
`1H-NMR(CDCl3) inter alia 60.99 (3H,s,18~CH3), 1.02(3H,
`s,19-CH3), 5.39(1H,m,6-H), 5.59(1H,m,16-H), 5.62(1H,m,
`3-H), 5.93(1H,dm,] 9.4 Hz,4-H); MS rn/z 402(M”). Further
`elution with light petroleum-dichloromethane (3:1) afforded
`the title compound (20.1 g, 58%) which crystallised from
`hexane, m.p. 75°-76° C. lH-NMR(CDCl3) inter al