New progesterone receptor antagonists: 3,3-disubstituted-5-aryloxindoles.

Article abstract of DOI:10.1016/S0960-894X(02)00746-1

A new series of 3,3-disubstituted-5-aryloxindoles has been synthesized and evaluated for progesterone receptor antagonist (PR) activity in a T47D cell alkaline phosphatase assay and for their ability to bind PR in competition binding studies. In this comm

Full text of DOI:10.1016/S0960-894X(02)00746-1

Bioorganic & Medicinal Chemistry Letters 12 (2002) 3487–3490
New Progesterone Receptor Antagonists:
3,3-Disubstituted-5-aryloxindoles
Andrew Fensome,a,* Reinhold Bender,a Jeffrey Cohen,b Mark A. Collins,a
Valerie A. Mackner,a Lori L. Miller,a John W. Ullrich,a Richard Winneker,b
Jay Wrobel,a Puwen Zhang,a Zhiming Zhangb and Yuan Zhub
aChemical Sciences, Wyeth Research, 500 Arcola Road, Collegeville, PA 19426, USA
bWomen’s Health Research Institute, Wyeth Research, 500 Arcola Road, Collegeville, PA 19426, USA
Received 18 April 2002; accepted 5 August 2002
Abstract—A new series of 3,3-disubstituted-5-aryloxindoles has been synthesized and evaluated for progesterone receptor antago-
nist (PR) activity in a T47D cell alkaline phosphatase assay and for their ability to bind PR in competition binding studies. In this
communication, the synthesis and structure–activity relationships (SARs) of various 3,3-substituents are discussed where it is clear
that small alkyl and spiroalkyl groups are required to achieve better PR antagonist activity.
# 2002 Elsevier Science Ltd. All rights reserved.
The progesterone receptor (PR) is a member of the
steroid receptor sub-family of the nuclear hormone
receptor super-family, a group of nuclear transcription
factors.1 Progesterone 1, the endogenous ligand for the
PR, is involved in the control of ovulation and pre-
paration of the uterus to support pregnancy (Fig. 1). In
principal a PR antagonist, may therefore have potential
utility as a contraceptive.2 In addition, PR antagonists
have potential applications in the treatment of repro-
ductive disorders such as uterine leiomyomas and
endometriosis, as well as hormone dependent
tumours.3ꢀ5
Most of the compounds were prepared by either method
A (Scheme 1, 5–13 and 15–20) or method B (Scheme 2,
21–32). The compounds exploring the 3,30 alkyl sub-
stitution pattern were prepared according to Scheme 1.
Oxindole 33 was alkylated according to Kende’s proce-
dure:8 thus treatment with n-butyllithium in the pre-
sence of TMEDA, followed by quenching the anion
with the appropriate alkyl iodide afforded the
substituted oxindoles 34. In the case of the spirocyclic
compounds, the dianion was formed with excess
n-butyllithium/TMEDA followed by addition of a di-
iodide. The bromides 35 were prepared by reaction of
The steroidal PR antagonist Mifepristone (RU-486) 2,
is potentially compromised as a clinically useful contra-
ceptive due to overt glucocorticoid receptor antagon-
ism.6 The goal of our study was to identify more
receptor specific non-steroidal PR antagonists. Examples
of non-steroidal PR antagonists have been described
previously.7 We decided to utilize the 5-aryldihy-
droquinoline 3 as a template,7f and during the course of
our work have succeeded in replacing the dihy-
droquinoline ring with an oxindole 4. This modification
has allowed us to further explore the 3,3-alkyl region of
the molecule.
*Corresponding author. Fax: +1-484-865-9398; e-mail: fensoma@
wyeth.com
Figure 1. Ligands for the PR.
0960-894X/02/$ - see front matter # 2002 Elsevier Science Ltd. All rights reserved.
PII: S0960-894X(02)00746-1

3488
A. Fensome et al. / Bioorg. Med. Chem. Lett. 12 (2002) 3487–3490
Scheme 3. Reagents and conditions: (a) Br2, NaOAc, AcOH, rt;
(b) Pd(Ph3P)4, 3-ClC6H4B(OH)2, Na2CO3, DME–H2O, 90 ꢁC.
Scheme 1. Reagents and conditions: (a) n-BuLi, TMEDA, THF
ꢀ78 ꢁC, then R-I; (b) Br2, NaOAc, AcOH, rt; (c) Pd(Ph3P)4,
ArB(OH)2, Na2CO3, DME–H2O, 90 ꢁC.
In the mono-substituted series the differences in hPR
antagonist activity were small. The unsubstituted oxin-
dole 6 had an IC50=296 nM in the T47D alkaline
phosphatase assay and the mono-methyl compound 8
and mono-ethyl derivative 9 had IC50=185 and
130 nM, respectively. The mono-alkyl derivatives were
all tested as racemates. Addition of a second 3-methyl
group to compounds 7 and 8 enhanced the potency
(T47D alkaline phosphatase IC50=30.6 and 66.4 nM
for dimethyl analogues 10 and 11, respectively). The 3,3-
diethyl derivative 12 lost about 3-fold in potency com-
pared to the dimethyl analogue 11 (IC50=229 nM).
We then looked at ring constrained spirocyclic oxin-
doles. The spirocyclopropane 13 and the spirocyclo-
butane 14 had comparable activity (IC50=85 and
70.7 nM, respectively). Increasing the ring size to a
spirocyclopentane improved potency; thus the 3-nitro-
phenyl derivative 15 and its 3-chlorophenyl analogue 16
had similar potency (IC50=38 and 32 nM, respectively).
The spirocyclohexanes 17 and 18 were similar in activity
to the spirocyclopentanes [IC50=36 nM (17) and 56 nM
(18)].
Scheme 2. Reagents and conditions: NaH, THF, n-BuLi, (iPrO)3B; (b)
Pd(Ph3P)4, ArBr, Na2CO3, DME–H2O, 90 ꢁC.
the precursor oxindole 34 with bromine and sodium
acetate in acetic acid. Finally a Suzuki coupling with the
appropriate bromide 35 and a phenylboronic acid in
the presence of tetrakis(triphenylphosphine)palladium
and sodium carbonate in either dimethoxyethane
(DME)/water or toluene/ethanol/water gave the desired
5-aryloxindoles 4.
We prepared one unsymmetrical analogue, the 3-
methyl-30-benzyloxindole 19, which was less potent than
the 3,30-dimethyl analogue 11 (IC50=267 nM).
Alternately, where the aryl boronic acid is not readily
available, Scheme 2 was followed, method B. Reaction
of the bromide 35 with sodium hydride in THF, then by
n-butyl lithium at ꢀ78 ꢁC was followed by quenching
with tri-iso-propyl borate to afford the boronic acid 36.
Coupling of 36 with an aryl or heteroaryl bromide then
gave the product 4.
Having optimized the 3,3-dialkyl oxindole core tem-
plate, attention turned to functionalisation of the 5-aryl
substituent (Table 1). The nature of the substituent on
the 5-phenyl group was important for activity. For
example replacing the nitro group with either a meth-
oxyl (20) or acetyl (21) substituent reduced activity
(T47D alkaline phosphatase IC50=30.6, 300 and
206 nM for compounds 10, 20 and 21, respectively). In
A different synthesis of the spirocyclobutane 14 was
followed (Scheme 3).9 The hydrazide 37 (prepared from
phenylhydrazine and cyclobutanecarbonylchloride in
DMF/pyridine) was mixed with CaH2 and heated to
200 ꢁC in the absence of solvent to afford the oxindole
38. Compound 38 was then brominated and coupled
with 3-chlorophenylboronic acid as described for
Scheme 1 to afford compound 14.
contrast
a
30-cyano group retained activity (22,
IC50=27 nM). A second small substituent could be
added to the 50-position of the phenyl group. Thus
adding a fluorine to compound 11 to give the analogue
23 enhanced potency (IC50=66.4 and 29 nM, respec-
tively). This was also true for the 30-cyano-50-fluoro (24)
which had IC50=13.2 nM but not for the 30-nitro-50-
fluoro (25) derivative which was equipotent with com-
pound 10 (IC50=27 and 30 nM, respectively). Increas-
ing the size of the second substituent from a fluorine to
a chlorine reduced activity (26 vs 10, IC50=100.1 and
66.4 nM respectively).
The compounds were evaluated for PR antagonist
activity based on their ability to block progesterone
induced alkaline phosphatase in the human breast can-
cer cell line T47D (Table 1).10 PR competition binding
studies were carried out using human T47D cell cytosol
3
in the presence of 3 nM H-R5020 as the radioligand.10

A. Fensome et al. / Bioorg. Med. Chem. Lett. 12 (2002) 3487–3490
3489
Table 1. Functional activity data in the T47D alkaline phosphatase data for compounds 2–3 and 5–26
Compd
R1a
R2a
R30a
R50a
Synthetic
method
Alkaline
phosphatase
IC50 (nM)b
hPR competition
IC50 (nM)
2
3
0.1
41
5
6
7
8
H
H
Me
Me
Et
Me
Me
Et
H
H
H
H
H
Me
Me
Et
NO2
Cl
NO2
Cl
Cl
NO2
Cl
Cl
Cl
Cl
NO2
Cl
NO2
Cl
Cl
MeO
Ac
CN
Cl
NO2
CN
Cl
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
F
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
B
B
B
B
B
B
B
B
B
B
B
B
B
299
296
102
185
130
30.6
66.4
229
85
70.7
38
32
36
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27c
28c
29c
30
31
32
33
509
–CH2CH2–
–CH2CH2CH2–
–CH2CH2CH2CH2–
–CH2CH2CH2CH2–
–CH2CH2CH2 CH2CH2–
–CH2CH2CH2 CH2CH2–
193
96
56
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Bn
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
267
300
206
27
29
27
F
F
Cl
13
100.1
28
29
2-Cyanothien-5-yl
2-Nitrothien-5-yl
2-Cyano-4-methylthien-5-yl
CN
CN
CN
CN
29
–CH2CH2CH2CH2–
H
H
F
20.6
14.7
13.6
20
–CH2CH2CH2 CH2CH2–
–CH2CH2CH2 CH2–
–CH2CH2CH2CH2CH2–
230
51
F
aRefer to structure (4) for numbering system.
bValues represent the average of at least duplicate determinations. The standard deviations for the assay was typically ꢂ20% of mean or less.
cStructures shown in Figure 2.
tive 22 was active at 27 nM, the spirocyclopentyl and
spirocyclohexyl derivatives 29 and 30 had IC50=20.6
and 14.7 nM, respectively.
Selected compounds were tested in the hPR competition
binding assay. The 3-nitrophenyl substituted com-
pounds were typically more potent than the 3-chloro-
phenyl derivatives. For example, the 3-nitrophenyl
spirocylohexyl oxindole 17 had an IC50=96 nM,
whereas its 3-chlorophenyl congener 18 had an
IC50=477 nM. It was also found that potency in the
competition assay increases across the series 3,3-dime-
Figure 2.
thyl 10, spirocyclopentyl 15 and spirocyclohexyl 17
(hPR competition IC50=509, 193, and 96 nM, respec-
tively). The most potent compound in the competition
assay was the spirocyclohexane 33 (IC50=51 nM). The
spirocyclopentyl analogue 32 was less potent
(IC50=230 nM).
We then looked at replacing the 5-phenyl group with a
2-substituted 5-thiophene, (Fig. 2). Again cyano and
nitro derivatives were the most potent. The 5-cyano-
thiophene 27 had similar potency to the corresponding
phenyl derivative 22 (IC50=28 and 27 nM, respectively).
Similarly the nitro derivatives 28 and 10 were equipo-
tent (IC50=29 and 30.6 nM, respectively). The addition
of a 30-methyl group to compound 27 had no effect on
in-vitro potency (29, IC50=29 nM).
Selected molecules were evaluated for activity in the rat
decidualisation assay11 (Table 2). The decidualisation
assay measures the ability of a test compound to block
the progesterone induced stimulation of the luminal
cells of the uterus. All of the compounds in Table 2
showed statistically significant (p <0.05) levels of
inhibition when administered orally at a dose of 3 mg/
kg. Generally it would appear that the spirocyclopentyl
derivatives are the most potent. For example the
As was the case with the 30-chloro and 30-nitrophenyl
derivatives, the activities of the 30-cyano-50-fluorophenyl
compounds did not vary too much with the nature of
the 3,3-dialkyl substituent. Thus, the dimethyl deriva-

3490
A. Fensome et al. / Bioorg. Med. Chem. Lett. 12 (2002) 3487–3490
2. (a) Ulmann, A.; Peyron, R.; Silvestre, L. Ann. N.Y. Acad.
Table 2. Activity in the rat decidual assay for compounds 2, 25 and
30–33
Sci. 1995, 761, 248. (b) Kekkonen, R.; Lahteenmaki, P.;
Luukkainen, T.; Tuominen, J. Fertil. Steril. 1993, 60, 610. (c)
Chwalisz, K; Stockemann, K. World Patent Application WO
96/19997, 1996; Chem Abstr. 125, 177412.
Compd
% inhib.a
2
25
30
31
32
33
100
40
60
40
70
50
3. Horwitz, K. B.; Tung, L.; Takimoto, G. S.; In Hormonal
Cancer; Vedeckis, W. V., Ed. Birkhaeuser: Boston, 1996; p
283.
aCompounds were dosed orally at 3 mg/kg. ( p<0.05).
4. Murphy, A. A.; Kettel, L. M.; Morales, A. J.; Roberts,
V. J.; Yen, S. S. J. Clin. Endo. Metab. 1993, 76, 513.
5. Kettel, L. M.; Murphy, A. A.; Mortola, J. F.; Liu, J. H.;
Ulmann, A.; Yen, S. S. Fertil. Steril. 1991, 56, 402.
6. Lazar, G.; Lazar, G. Jr.; Husztik, E.; Duda, E.; Agarwal,
K. K. Ann. N.Y. Acad. Sci. 1995, 277, 248.
dimethyl substituted 30cyano-50fluoro compound 25
showed 40% inhibition at 3 mg/kg po, whereas the
spiropentyl analogue 32 displayed 70% inhibition at the
same dose. The spirocyclohexane 33 was similar to
compound 32 (60% inhibition at 3 mg/k po). None of
the compounds in the series were as potent as mifepristone
2 (100% inhibition at 3 mg/kg po, IC50=0.5 mg/kg po).
7. (a) Combs, D. W.; Reese, K.; Cornelius, L. A.; Gunnet,
J. W.; Cryan, E. V.; Granger, K. S.; Jordan, J. J.; Demarest,
K. T. J. Med. Chem. 1995, 38, 4880. (b) Combs, D. W.; Reese,
K.; Phillips, A. J. Med. Chem. 1995, 38, 4878. (c) Hamann,
L. G.; Higuchi, R. I.; Zhi, L.; Edwards, J. P.; Wang, X. N.;
Marschke, K. B.; Kong, J. W.; Farmer, L. J.; Jones, T. J.
Med. Chem. 1998, 41, 623. (d) Kurihara, K.; Tanabe, K.;
Yamamoto, Y.; Shinei, R.; Ajito, K.; Okonogi, T. Bioorg.
Med. Chem. Lett. 1999, 9, 1837. (e) Pooley, C. L. F.; Edwards,
J. P.; Goldman, M. E.; Wang, M.; Marschke, K. B.; Crombie,
D. L.; Jones, T. J. Med. Chem. 1998, 41, 3461. (f) Zhi, L.;
Tegley, C. M.; Pio, B.; West, S. J.; Marschke, K. B.; Mais,
D. E.; Jones, T. K. Bioorg. Med. Chem. Lett. 2000, 10, 415. (g)
Zhang, P.; Terefenko, E. A.; Wrobel, J.; Zhang, Z.; Zhu, Y.;
Cohen, J.; Marschke, K. B.; Mais, D. Bioorg. Med. Chem.
Lett. 2001, 11, 2747.
In summary, we have prepared a novel series of hPR
antagonists based upon the 5-aryl oxindole scaffold.
The most active of these derivatives had either a 3,30-
dimethyl or 3,30-spirocyclopentyl or spirocyclohexyl
substitution pattern. In-vivo activity has been achieved
in the rat decidualisation assay where the most potent
compound was the 30-cyano-50-fluorophenyl derivative
32.
Acknowledgements
8. Kende, A. S.; Hodges, J. C. Synth. Commun. 1982, 12,
1.
9. Robertson, D. W.; Krushinski, J. H.; Pollock, G. D.; Wil-
son, H.; Kauffman, R. F.; Hayes, J. S. J. Med. Chem. 1987, 30,
824.
The authors gratefully acknowledge the Department of
Analytical Chemistry for analytical data.
10. (a) Zhang, Z.; Lundeen, S. G.; Zhu, Y.; Carver, J. M.;
Winneker, R. C. Steroids 2000, 65, 637. (b) Beck, C. A.; Wei-
gel, N. L.; Moyer, M. L.; Nordeen, S. K.; Edwards, D. Proc.
Natl. Acad. Sci. U.S.A. 1993, 90, 4441.
11. Zhang, Z.; Funk, C.; Glasser, S. R.; Mulholland, J.
Endocrinology 1994, 135, 1256.
References and Notes
1. Mangelsdorf, D. J.; Thummel, C.; Beato, M.; Herrlich, P.;
Schutz, G.; Umesono, K.; Blumberg, B.; Kastner, P.; Mark,
M.; Chambon, P.; Evans, R. M. Cell 1995, 83, 835.