17β-Arylsulfonamides of 17β-aminoestra-1,3,5(10)-trien-3-ol as highly potent inhibitors of steroid sulfatase

Article abstract of DOI:10.1016/j.bmc.2011.12.036

Steroid sulfatase (STS) catalyzes the desulfation of biologically inactive sulfated steroids to yield biologically active desulfated steroids and is currently being examined as a target for therapeutic intervention for the treatment of breast and other steroid-dependent cancers. Here we report the synthesis of a series of 17β-arylsulfonamides of 17β-aminoestra-1,3, 5(10)-trien-3-ol and their evaluation as inhibitors of STS. Some of these compounds are among the most potent reversible STS inhibitors reported to date. Introducing n-alkyl groups into the 4′-position of the 17β-benzenesulfonamide derivative resulted in an increase in potency with the n-butyl derivative exhibiting the best potency with an IC₅₀ of 26 nM. A further increase in carbon units (to n-pentyl) resulted in a decrease in potency. Branching of the 4′-n-propyl group resulted in a decrease in potency while branching of the 4′-n-butyl group (to a tert-butyl group) resulted in a slight increase in potency (IC₅₀= 18 nM). Studies with 3′- and 4′-substituted substituted 17β-benzenesulfonamides with small electron donating and electron withdrawing groups revealed the 3′-bromo and 3′-trifluoromethyl derivatives to be excellent inhibitors with IC₅₀'s of 30 and 23 nM, respectively. The 17β-2′-naphthalenesulfonamide was also an excellent inhibitor (IC₅₀= 20 nM) while the 17β-4′-phenylbenzenesulfonamide derivative was the most potent inhibitor of all the compounds studied with an IC₅₀ of 9 nM.

Full text of DOI:10.1016/j.bmc.2011.12.036

Bioorganic & Medicinal Chemistry 20 (2012) 1535–1544
Contents lists available at SciVerse ScienceDirect
Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com/locate/bmc
17b-Arylsulfonamides of 17b-aminoestra-1,3,5(10)-trien-3-ol as highly
potent inhibitors of steroid sulfatase
⇑
Yaser A. Mostafa, Scott D. Taylor
Department of Chemistry, University of Waterloo, 200 University Ave. West, Waterloo, Ontario, Canada N2L 3G1
a r t i c l e i n f o
a b s t r a c t
Article history:
Steroid sulfatase (STS) catalyzes the desulfation of biologically inactive sulfated steroids to yield biolog-
ically active desulfated steroids and is currently being examined as a target for therapeutic intervention
for the treatment of breast and other steroid-dependent cancers. Here we report the synthesis of a series
of 17b-arylsulfonamides of 17b-aminoestra-1,3,5(10)-trien-3-ol and their evaluation as inhibitors of STS.
Some of these compounds are among the most potent reversible STS inhibitors reported to date. Intro-
ducing n-alkyl groups into the 40-position of the 17b-benzenesulfonamide derivative resulted in an
increase in potency with the n-butyl derivative exhibiting the best potency with an IC50 of 26 nM. A fur-
ther increase in carbon units (to n-pentyl) resulted in a decrease in potency. Branching of the 40-n-propyl
group resulted in a decrease in potency while branching of the 40-n-butyl group (to a tert-butyl group)
resulted in a slight increase in potency (IC50 = 18 nM). Studies with 30- and 40-substituted substituted
17b-benzenesulfonamides with small electron donating and electron withdrawing groups revealed the
30-bromo and 30-trifluoromethyl derivatives to be excellent inhibitors with IC50’s of 30 and 23 nM, respec-
tively. The 17b-20-naphthalenesulfonamide was also an excellent inhibitor (IC50 = 20 nM) while the
17b-40-phenylbenzenesulfonamide derivative was the most potent inhibitor of all the compounds stud-
ied with an IC50 of 9 nM.
Received 25 October 2011
Revised 14 December 2011
Accepted 18 December 2011
Available online 5 January 2012
Keywords:
Steroid sulfatase
Hormone therapy
Enzyme inhibitors
Inhibitors
Steroids
Breast cancer
Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction
source of biologically active steroid hormones when activated by
STS.
The majority of breast cancers require steroids in their early
stages of growth. Hence, compounds capable of interfering with
theactionof steroids onbreastcancer cells or inhibitingthe enzymes
involved in steroid biosynthesis have been pursued as therapeutics
for treating these diseases for several decades now.1 Aromatase
inhibitors are examples of the latter class of compounds and have
been used successfully in clinic for treating breast cancer.1,2 Other
enzymesthatarebeingtargetedare17b-hydroxysteroiddehydroge-
nase (17b-HSD) and steroid sulfatase (STS). STS catalyzes the desu-
flation of biologically inactive suflated steroids such as estrone
sulfate(E1S)anddehydroepiandrosteronesulfate(DHEAS)intotheir
desulfated counterpartssuch as estrone (E1) and dehydroepiandros-
terone (DHEA) (Fig. 1). 17b-HSD converts these into estradiol or
androstenediol which bind to the estrogen receptor in the nuclear
membrane.
STS expression is detected in 90% of breast tumors,5,6 which is
considerably greater than aromatase expression which is only
found in 60–70% of breast tumors.7,8 Moreover, STS mRNA expres-
sion is elevated in breast tumors compared to normal tissue9 and
STS activity in breast tumors is significantly higher than aromatase
activity.10 Clinical studies have now shown that elevated STS
mRNA expression may be a predictor of recurrence in breast cancer
patients with estrogen receptor positive (ER+) tumors.11 STS activ-
ity is approximately 50 times greater in breast tumors compared
with normal breast tissue.12 Taken together, these findings suggest
that STS plays an important role in breast cancer and that STS
inhibitors may be effective breast cancer therapeutics.
A vast array of STS inhibitors have been reported.13 The majority
are aryl sulfamates which act as irreversible, suicide inhibitors.
667-Coumate (1, Fig. 2) is an example of such a compound
(IC50 = 350 nM in intact MCF-7 cells13b) and has been examined in
Phase I clinical trials for treating breast cancer.14 Reversible STS
Circulating plasma concentrations of E1S and DHEAS are signifi-
cantly higher than E1 and DHEA.3 In addition, the half-life of E1S
and DHEAS in plasma is about 10–12 h, which is considerably longer
than the 30–40 min half-life of E1 and DHEA.4 For these reasons, the
role of sulfated steroids is seen as a storage reservoir that acts as a
inhibitors have also been developed.13 Among these are the 17
a-
benzylestradiol derivatives of type 2 which are potent inhibitors.13
It has been proposed that the high affinity of these compounds for
STS is a result of the benzyl moiety extending into a hydrophobic
channel between two alpha helices located just outside the active
site.13a As part of our efforts on the development of STS inhibitors,
⇑
Corresponding author. Tel.: +1 519 888 4567; fax: +1 519 746 0435.
E-mail address: s5taylor@sciborg.uwaterloo.ca (S.D. Taylor).
0968-0896/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2011.12.036

1536
Y. A. Mostafa, S. D. Taylor / Bioorg. Med. Chem. 20 (2012) 1535–1544
O
O
OH
STS
17β-HSD
sulfo-
transferase
O
S
-
O
O
HO
HO
O
estrone
estradiol
estrone sulfate
nucleus
O
O
OH
estrogen
receptor
STS
17β-HSD
cancer cell
O
S
O
sulfo-
-
transferase
O
O
HO
dehydroepiandrosterone
HO
androstenediol
dehydroepiandrosterone
sulfate
Figure 1. Examples of reactions catalyzed by STS and 17b-HSD.
O
R
S
R
HO
HN
O
H
O
H2N
S
O
O
O
HO
O
HO
2 R = H or hydrophobic
1 (667-Coumate)
3
IC50 = 350 nM with
intact MCF-7 cells
group
IC50's 20-1000 nM
in homogenates
of JEG-3 cells
Figure 2. Irreversible and reversible inhibitors of STS.
we wished to determine whether other estrogen derivatives bearing
other groups at the 17-position could also act as potent STS inhibi-
tors. Here we report that 17b-sulfonamides (3, Fig. 2) of 17b-amino-
estra-1,3,5(10)-trien-3-ol can be highly potent inhibitors of steroid
sulfatase and some of these compounds are among the most potent
reversible STS inhibitors reported to date.
R1
R1
R2
R2
p-TsCl
pyridine
HO
HO
6, R1 = NHSO2-p-Tol, R2 = H (40%)
7, R1 = H, R2 = NHSO2-p-Tol (56%)
4, R1 = NH2, R2 = H
5, R1 = H, R2 = NH2
2. Results and discussion
2.1. Inhibition studies
Scheme 1. Synthesis of sulfonamide 6 and 7.
We focused upon examining 17-sulfonamides of 17-aminoes-
tra-1,3,5(10)-trien-3-ol as potential STS inhibitors for several rea-
sons. First, we anticipated that their synthesis could be readily
accomplished by reacting 17-aminoestra-1,3,5(10)-trien-3-ol with
sulfonyl chlorides. Second, dozens of sulfonyl chlorides are com-
mercially available and so a large number of potential inhibitors
could be readily prepared. Third, the sulfonamide group is chemi-
cally stable and usually exhibits good metabolic stability. It is one
of the most important pharmacophores in medicinal chemistry,
and numerous bioactive agents bear this functionality.15
The IC50’s of 6 and 7 and all subsequent IC50’s reported within
were obtained using purified STS in Tris buffer at pH 7.0 containing
0.01% Triton X-100, 5% DMSO and using 4-methylumbelliferyl sul-
fate (4-MUS) as the substrate.18,19 The b-isomer 6 proved to be a
good STS inhibitor with an IC50 of 207 nM while the
a-isomer 7
was less potent with an IC50 of 341 nM. The finding that the b-iso-
mer was the better inhibitor was somewhat surprising as this is
the opposite stereochemistry to that of the benzyl groups in the
17a-benzylestradiol inhibitors of type 2. We also prepared the
17b- and 17a-p-toluenesulfonamides 6 and 7 (Scheme 1) were
17b-sulfonate 12 (Scheme 2). Compound 12 also proved to be a
good inhibitor of STS (IC50 = 293 nM) but was not as potent as
b-sulfonamide analog 6.
On the basis of the above studies, subsequent efforts focused on
preparing a collection of 17b-arylsulfonamides of 6. These com-
pounds were readily prepared using the same approach as outlined
in Scheme 1 for the synthesis of 6. Our initial efforts focused on
phenylsulfonamides substituted at the 40-position with hydropho-
bic groups (Table 1) as it has been previously demonstrated that
used as model compounds to determine if this approach had any
promise of providing potent STS inhibitors and if the stereochem-
istry at the 17-position would have an influence on inhibitor po-
tency. 17b-Aminoestra-1,3,5(10)-trien-3-ol (4) was synthesized
using an efficient two-step sequence we recently reported starting
from estrone,16 and 17
a-aminoestra-1,3,5(10)-trien-3-ol (5) was
easily prepared via a four-step sequence starting from estradiol.17
Compounds 6 and 7 were prepared by slowly adding a solution of
p-toluenesulfonyl chloride to a solution of 4 or 5 in pyridine (not
optimized).
17
a-benzylestradiol derivatives of type 2 bearing certain hydro-
phobic groups at the 40-position of the benzyl moiety are potent

Y. A. Mostafa, S. D. Taylor / Bioorg. Med. Chem. 20 (2012) 1535–1544
1537
O
O
OH
H
BnBr, K2CO3
acetone, reflux,
12 h
NaBH4, EtOH/
THF, 0 oC, 1 h
HO
BnO
BnO
9 (91 %)
10 (74 %)
OSO2p-Tol
8 (E1)
OSO2p-Tol
H
H
p-TolSO2Cl, pyr,
oC-rt, O/N
0
H2, cat. Pd/C
BnO
HO
11 (68 %)
12 (71 %)
Scheme 2. Synthesis of sulfonate 12.
STS inhibitors.20a,b The parent benzenesulfonamide 13 as well as
benzyl derivative 14 and 40-methylbenzyl sulfonamide 15 were
poorer inhibitors than tosyl derivative 6 mentioned previously.
However, increasing the length of the n-alkyl group at the 40-pos-
iton in the benzenesulfonamide moiety from one (methyl, com-
pound 6) to four carbons (n-butyl derivative 17) resulted in a
significant increase in binding affinity with n-butyl derivative 17
being a potent inhibitor with an IC50 of 26 nM. However, a decrease
in affinity occurred with when a fifth carbon unit was present (n-
pentyl derivative 18). Branching of the n-propyl group proved to
be slightly detrimental to binding affinity (isopropyl derivative
19) while the tert-butyl derivative 20 proved to be more potent
than the n-butyl derivative with an IC50 of 18 nM. The presence
of a phenyl group at the 40-position (biphenyl derivative 21)
yielded a highly potent inhibitor with an IC50 of 9 nM. The 40-phen-
oxy derivative 22 proved to be over four-fold less potent than the
biphenyl derivative. The 20-naphthalene derivative 23 was also an
excellent inhibitor with an IC50 of 20 nM.
Further studies were conducted with a series of compounds
bearing small electron withdrawing and electron donating substit-
uents at the 30- and/or 40-positions (Table 2). It has been reported
that the 17b-30-bromobenzyl estradiol is a potent inhibitor of STS
with an IC50 of 24 nM.20a,c The 30-bromo derivative 25 also proved
to be a potent STS inhibitor with an IC50 of 25 nM while the 20- and
40-bromo derivatives 24 and 26 were considerably less potent. Fur-
ther interrogation of the 30-, and 40-position with a variety of elec-
tron withdrawing and electron donating groups (Table 2) failed to
produce a more potent inhibitor than 25 with the exception of the
30-trifluoromethyl derivative 33 which had an IC50 of 23 nM. The
30-bromo derivative, 25, was chosen for more detailed kinetics
analysis. This compound exhibited mixed inhibition (Fig. 3) with
Table 1
Inhibition of steroid sulfatase with 17b-40-alkylbenzenesulfonamides and arylsulfon-
amides of 17b-aminoestra-1,3,5(10)-trien-3-ol
O
S
H
R
N
O
H
HO
a
Compound
R
IC50 (nM)
13
14
15
6
16
17
18
19
20
21
22
23
Benzene
Benzyl
343
364
261
207
44
26
51
62
40-Methylbenzyl
40-Methylbenzene
40-n-Propylbenzene
40-n-Butylbenzene
40-n-Pentylbenzene
40-isoPropylbenzene
40-tert-Butylbenzene
40-Phenylbenzene
40-Phenoxybenzene
20-Naphthalene
18
9
39
20
a
Errors in IC50’s are within 5%.
Table 2
Inhibition of Steroid Sulfatase with 17b-benzene sulfonamides 24–37
O
S
H
R
N
O
H
1.6
1.4
1.2
1
HO
a
Compound
R
IC50 (nM)
24
25
26
27
28
29
30
31
32
33
34
35
36
37
20-Bromobenzene
493
25
190
67
271
90
137
112
479
23
30-Bromobenzene
40-Bromobenzene
30-Chlorobenzene
40-Chlorobenzene
30-Nitrobenzene
30-Cyanobenzene
30-Fluorobenzene
40-Fluorobenzene
0.8
0.6
0.4
0.2
0
30-Trifluoromethylbenzene
40-Trifluoromethylbenzene
30-Methylbenzene
-0.02
-0.015
-0.01
-0.005
0
0.005
0.01
0.015
73
65
193
74
-0.2
1/ [MUS] (µM-1)
30-Methoxybenzene
30-Trifluoromethoxybenzene
Figure 3. Lineweaver–Burk plot for the inhibition of STS by compound 25. ꢀ (no
inhibitor), j (25 nM 25), N (50 nM 25), d (75 nM 25).
a
Errors in IC50’s are within 5%.

1538
Y. A. Mostafa, S. D. Taylor / Bioorg. Med. Chem. 20 (2012) 1535–1544
O
O
NH2
H
F3C
HN
O
HN
K2CO3
, pyr
O
Cl
H
MeOH/H2O
H
CF3
CF3
HO
38 (57%)
39 (74%)
HO
F3C
O
Scheme 3. Synthesis of compound 39.
a Ki of 23 nM and an
a
Ki of 108 nM. We reported that a compound
20-naphthalene (23), 30-bromo (25), and 30-trifluoromethyl (33)
derivatives are among the most potent reversible STS inhibitors re-
ported to date. Studies on the antiproliferative activity of these
compounds with various breast cancer cell lines are in progress
and will be reported in due course.
of type 2 (R = H) also exhibited mixed inhibition.21
To determine if a 17b-amide linkage between the aryl moiety
and C-17 is as effective as a 17b-sulfonamide linkage we prepared
the amide analog of 33 (compound 39, Scheme 3) and evaluated it
as an STS inhibitor. Surprisingly, amide 39 was a much poorer inhib-
itor with an IC50 of 749 nM. The trifluoromethyl group in 33 may be
interacting with a site on STS that is not accessible to the trifluoro-
methyl group in the benzamide. This may be a result of the signifi-
cant structural differences between amides and sulfonamides.22
A comparisonof theIC50’s ofthe compoundsdescribedhere to the
4. Experimental
4.1. General
All starting materials and reagents were obtained from Sigma
Aldrich Canada Ltd. THF was distilled from sodium-benzophenone.
CH2Cl2 was distilled from calcium hydride under nitrogen. Silica
gel chromatography was performed using silica gel (60 Å, 230–
400 mesh) obtained from Silicycle (Laval, Quebec, Canada). 1H,
13C, and 19F NMR spectra were recorded on a Bruker Avance 300
spectrometer. For NMR spectra obtained using CDCl3 as the sol-
vent, chemical shifts (d) for 1H NMR spectra are reported relative
to internal Me4Si (d 0.0 ppm), chemical shifts for 13C spectra are
relative to the residual solvent peak (d 77.0 ppm, central peak),
and chemical shifts for 19F NMR are relative to a trichlorofluoro-
methane (d 0.0 ppm) external standard. Low-resolution (LRMS)
and high-resolution (HRMS) electron impact (EI) mass spectra
were obtained on a JEOL HX110 double focusing mass spectrome-
ter. Melting points were determined on a Fisher–Johns melting
point apparatus and are uncorrected. Steroid sulfatase from human
placenta was purified as previously described.19 Fluorimetry was
performed using a Spectramax GeminiXS plate reader (Molecular
Devices, CA) at 25 °C.
17a-benzylestradiol inhibitorsreportedby Poirierand co-workersis
of interest as this analysis reveals some similarities as well as some
significant differences. Poirier and co-workers have suggested that
the enhanced affinity of the 17a-benzylestradiol inhibitors com-
pared to estradiol is a result of the benzyl group projecting into a
channel between the two hydrophobic alpha helices that insert
STS into the membrane of the endoplasmic reticulum.13a It is likely
that the aryl sulfonamide moiety of the compounds reported here
also projects into this tunnel. The finding that the IC50’s of the benzyl
(14), 40-n-butyl (17) and 40-tert-butyl (20) inhibitors are very similar
to the analogous 17a
-benzylestradiol inhibitors20a is probably be-
cause the alkyl group in both series of compounds form non-specific
hydrophobic interactions with the hydrophobic residues located in
the channel. The finding that 30-bromo derivatives of both series
are potent inhibitors with similar IC50’s would further support the
suggestion that both series of compounds interact with STS in a sim-
ilar manner in spite of the fact that the 17b-sulfonamide link be-
tween the aryl moieties and carbon-17 in the inhibitors described
hereis structurally, electronicallyandspatially(b vs
a) verydifferent
from the 17 -CH2 unit in the 17 -benzylestradiol inhibitors and
a
a
4.2. Syntheses
lacks a 17-OH group. However, some differences in IC50’s between
the two sets of compounds suggest that this may not always be the
case. For examples, the 40-biphenyl derivative 21 (IC50 = 9 nM) and
naphthyl derivative 23 (IC50 = 20 nM) are 4-fold and 6-fold more
4.2.1. 3-Benzyloxyestrone (9)
Potassium carbonate (1.38 mmol) was added to a stirred solu-
tion of estrone (E1, 0.9 mmol) in anhydrous acetone (10 mL), and
the resulting suspension was stirred for 1 h. Benzyl bromide
(1.1 mmol) was added and the mixture was heated to reflux for
4 h. The mixture was poured into ice/water then extracted with
ethyl acetate. The combined extracts were washed with water then
dried (Na2SO4), filtered, and concentrated. The resulting pale yel-
low crude solid was recrystallized from ethanol to yield compound
potent than 17
17
-naphth-20-ylmethylestradiol (IC50 = 120 nM).20b,c The 30-triflu-
a
-40-phenylbenzylestradiol (IC50 of 35 nM) and the
a
oromethylbenzenesulfonamide derivative 33 (IC50 = 23 nM) is
almost six-fold more potent than 17b-30-trifluoromethylbenzylest
radiol (IC50 = 126 nM).20b,c In any case, it should be pointed out that
the two classes of compounds were assayed under different condi-
10 as white crystals (91%). Mp 132–133 °C (lit 132–134 °C)23 1H
;
tions (the IC50’s of 17a-benzyl estradiol inhibitors were determined
using homogenates of JEG-3 cells in Tris-acetate buffer, 10% glycerol,
pH 7.0 and [3H]E1S as substrate20b while our work was done with
pure STS in Tris buffer, pH 7.0, Triton, and 5% DMSO using 4-MUS
as substrate) suggesting that caution should be applied when com-
paring their IC50’s.
NMR (CDCl3, 300 MHz) d 7.42–7.29 (m, 5H, C6H5), 7.18 (d,
J = 8.6 Hz, 1H, H-1), 6.77 (d, J = 8.5 Hz, 1H, H-2), 6.72 (br s, 1H, H-
4), 5.02 (s, 2H, C6H5CH2), 2.88–2.86 (m, 2H), 2.53–2.35 (m, 2H),
2.24–1.88 (m, 4H), 1.63–1.41 (m, 7H), 0.89 (s, 3H, CH3, H-18).
4.2.2. 3-Benzyloxyestra-1,3,5(10)-trien-17b-ol (10)
3. Conclusions
To a solution of compound 9 (0.5 mmol) in ethanol/THF (6 mL,
5:1) at 0 °C was added NaBH4 (1 mmol). The resulting mixture
was stirred for 1 h at 0 °C then the reaction was quenched with
1 M HCl. After extraction with ethyl acetate, the combined extracts
were washed with water and satd brine then dried (Na2SO4),
We have shown that 17b-arylsulfonamides of 17b-aminoestra-
1,3,5(10)-trien-3-ol can be highly potent inhibitors of STS. Some of
these compounds, such as the 40-tert-butyl (20), 40-biphenyl (21),

Y. A. Mostafa, S. D. Taylor / Bioorg. Med. Chem. 20 (2012) 1535–1544
1539
filtered, and concentrated. Purification of the residue by flash chro-
4.2.7. 17a-Toluenesulfonamide-1,3,5(10)-estratrien-3-ol (7)
matography (ethyl acetate/hexane, 1:4) gave compound 10 as a
Purification was achieved using flash chromatography (ethyl
acetate/hexane, 1:9) which provided 7 as a white solid (47%). Mp
131–132 °C; 1H NMR (CDCl3, 300 MHz), d 7.72 (d, J = 8.2 Hz, 2H,
ArH-a), 7.28 (d, J = 8.0 Hz, 2H, ArH-b), 7.08 (d, J = 8.4 Hz, 1H, H-1),
6.64 (dd, J = 8.4 and 2.7 Hz, 1H, H-2), 6.53 (d, J = 2.5 Hz, 1H, H-4),
5.03 (br s, 1H, Ar-OH), 4. 50 (d, J = 9.1 Hz, 1H, NH), 3.29 (t,
J = 8.3 Hz, 1H, H-17), 2.75 (m, 2H), 2.41 (s, 3H, C6H4–CH3), 2.25–
2.21 (m, 2H), 2.08–2.03 (m, 1H), 1.79–1.58 (m, 3H), 1.52–1.51
(m, 1H), 1.41–1.40 (m, 1H), 1.37–1.05 (m, 6H), 0.69 (s, 3H, CH3,
H-18); 13C NMR (CDCl3, 75 MHz) d 153.3 (C-3), 143.1 (C–CH3),
138.3 (C–SO2NH–), 138.0 (C-5), 132.4 (C-6), 129.0 (2ArCH-b),
127.1 (2ArCH-a), 126.5 (C-1), 115.2 (C-4), 112.8 (C-2), 62.5 (C-
17), 49.6 (C-14), 44.89 (C-13), 43.2 (CH), 38.9 (CH), 32.7 (CH2),
31.2 (CH2), 29.6 (CH2), 27.8 (CH2), 26.0 (CH2), 24.0 (CH2), 21.5
(C6H4–CH3), 18.2 (CH3, C-18); LRMS (ESI+) m/z (%) 426 (M+H, 20),
255 (100); HRMS (ESI+) calcd for C25H32NO3S (M+H)+ 426.2103;
found 426.2104.
white solid (74%). Mp 62–63 °C (lit 61–63 °C)24 1H NMR (CDCl3,
;
300 MHz) d 7.44–7.31 (m 5H, C6H5), 7.21 (d, J = 8.6 Hz, 1H, H-1),
6.78 (d, J = 8.5 Hz, 1H, H-2), 6.73 (br s, 1H, H-4), 5.03 (s, 2H,
C6H5CH2), 3.72 (t, J = 7.8 Hz, 1H, H-17), 2.85–2.83 (m, 2H), 2.33–
2.28 (m, 1H), 2.23–2.08 (m, 2H), 1.97–1.86 (m, 2H), 1.71–1.68
(m, 1H), 1.51–1.14 (m, 7H), 0.78 (s, 3H, CH3, H-18).
4.2.3. 3-Benzyloxy-17b-toluenesulfonyl-estra-1,3,5(10)-trien-
17b-ol (11)
To a stirred solution of compound 10 (0.69 mmol) in anhydrous
pyridine (2 mL) at 0 °C was added p-toluenesuflonylchloride
(1.03 mmol) portion-wise. The solution was stirred at room tem-
perature for 16 h. The pyridine was removed under vacuum, the
residue was dissolved in ethyl acetate, then washed with 2 N
HCl, water and brine then dried (Na2SO4), filtered and concen-
trated. The residue was purified by flash chromatography (ethyl
acetate/hexane, 7:3), to give 11 as a white solid (68%). Mp 115–
117 °C (lit 115–117 °C)25 1H NMR (CDCl3, 300 MHz) d 7.80 (d,
;
4.2.8. 17b-Benzenesulfonamide-1,3,5(10)-estratrien-3-ol (13)
Purification was achieved using flash chromatography (ethyl
acetate/hexane, 1:4) which provided 13 as a white solid (67%).
Mp 234–235 °C; 1H NMR (CDCl3, 300 MHz) d 7.88 (d, J = 8.1 Hz,
2H, ArH-a & a0), 7.58–7.47 (m, 3H, ArH-b, b0 & c), 7.09 (d,
J = 8.4 Hz, 1H, H-1), 6.59 (d, J = 8.4 Hz, 1H, H-2), 6.52 (s, 1H, H-4),
4.60 (s, 1H, Ar-OH), 4.48 (d, J = 9.2 Hz, 1H, NH), 3.15 (q, J = 8.9 Hz,
1H, H-17), 2.75 (m, 2H), 2.21–2.16 (m, 2H), 1.88–1.60 (m, 4H),
1.42–1.07 (m, 7H), 0.68 (s, 3H, CH3, H-18); 13C NMR (CDCl3,
75 MHz) d 153.3 (C-3), 141.1 (C–SO2NH–), 138.1 (C-5), 132.5
(ArCH), 132.4 (C-6), 129.0 (2ArCH), 127.1 (2ArCH), 126.5 (C-1),
115.2 (C-4), 112.7 (C-2), 63.4 (C-17), 51.1 (C-14), 43.7 (CH), 42.9
(C-13), 38.8 (CH), 36.3 (CH2), 29.5 (2CH2), 27.1 (CH2), 26.0 (CH2),
23.1 (CH2), 11.8 (CH3, C-18); LRMS (ESI+) m/z (%) 412 (M+H, 100),
255 (18); HRMS (ESI+) calcd for C24H30NO3S (M+H)+ 412.1946;
found 412.1950.
J = 7.8 Hz, 2H, 2ArH-a), 7.42–7.32 (m, 7H, ArH’s), 7.15 (d,
J = 8.5 Hz, 1H, H-1), 6.76 (d, J = 8.4 Hz, 1H, H-2), 6.70 (br s, 1H, H-
4), 5.01 (s, 2H, C6H5–CH2), 4.35 (t, J = 8.1 Hz, 1H, H-17), 2.81 (m,
2H), 2.45 (s, 3H, OSO2C6H4–CH3), 2.24–2.10 (m, 2H), 1.99–1.92
(m, 1H), 1.85–1.61 (m, 4H), 1.43–1.26 (m, 4H), 1.16–1.08 (m,
2H), 0.83 (s, 3H, CH3, H-18).
4.2.4. 17b-Toluenesulfonyloxy-estra-1,3,5(10)-trien-3-ol (12)
To a solution of compound 11 (0.14 mmol) in a methanol/ethyl
acetate (1:1, 5 mL) and a catalytic amount of acetic acid (100 lL)
was added Pd(OH)2 (0.8 equiv). The mixture was stirred under H2
gas for 16 h then filtered and concentrated. Purification of the res-
idue by flash chromatography (ethyl acetate/hexane, 8:2) gave
compound 12 as a white solid (71%). Mp 185–186 °C (lit 186–
187 °C)26
;
1H NMR (CDCl3, 300 MHz) d 7.78 (dd, J = 6.6 and
1.7 Hz, 2H, ArH-a), 7.33 (d, J = 6.6 Hz, 2H, ArH-b), 7.08 (d,
J = 8.5 Hz, 1H, H-1), 6.59 (dd, J = 8.4 and 2.7 Hz, 1H, H-2), 6.52 (d,
J = 2.7 Hz, 1H, H-4), 4.59 (s, 1H, Ar-OH), 4.33 (q, J = 7.7 Hz, 1H, H-
17), 2.78–2.75 (m, 2H), 2.43 (s, 3H, OSO2C6H4–CH3), 2.09–1.95
(m, 3H), 1.78–1.67 (m, 4H), 1.41–1.33 (m, 4H), 1.14–1.09 (m,
2H), 0.81 (s, 3H, CH3, H-18).
4.2.9. 17b-Benzylsulfonamide-1,3,5(10)-estratrien-3-ol (14)
Purification was achieved using flash chromatography (100%
chloroform then methanol/chloroform, 1:9) which provided 14 as
a white solid (26%). Mp 202–203 °C; 1H NMR (CDCl3, 300 MHz) d
7.40–7.35 (m, 5H, ArH), 7.11 (d, J = 8.4 Hz, 1H, H-1), 6.60 (dd,
J = 8.4 and 2.6 Hz, 1H, H-2), 6.53 (d, J = 2.5 Hz, 1H, H-4), 4.79 (br
s, 1H, Ar-OH), 4.23 (AB system, 2H, J = 13.9 and 13.9 Hz, 2H, Ar-
CH2), 4.09 (d, J = 9.2 Hz, 1H, NH), 3.23 (q, J = 8.4 Hz, 1H, H-17),
2.77 (m, 2H), 2.28–2.09 (m, 3H), 1.94–1.68 (m, 3H), 1.42–1.18
(m, 7H), 0.65 (s, 3H, CH3, H-18); 13C NMR (CDCl3, 75 MHz) d
153.4 (C-3), 138.1 (C-5), 132.4 (C-6), 130.7 (2ArCH), 129.4, 128.7
(2ArCH), 126.5 (C-1), 115.2 (C-4), 112.7 (C-2), 63.8 (C-17), 59.7
(ArCH2SO2NH), 51.1 (C-14), 43.7 (CH), 42.9 (C-13), 38.9 (CH),
36.5 (CH2), 29.9 (CH2), 29.5 (CH2), 27.1 (CH2), 26.1 (CH2), 23.1
(CH2), 11.8 (CH3, C-18); LRMS (EI) m/z (%) 425 (M+, 100), 270
(35), 213, 91; HRMS (EI) calcd for C25H31NO3S 425.2025; found
425.2018.
4.2.5. General procedure for synthesis of sulfonamides of 17-
amino-1,3,5(10)-estratrien-3-ol
To
a stirred solution of 17-amino-1,3,5(10)-estratrien-3-ol
(0.38 mmol) in dry pyridine (3 mL) at 0 °C was added a solution
of the sulfonyl chlorides (0.40 mmol) in dichloromethane (1 mL)
via a syringe pump over 30 min. After addition, the reaction was
stirred for 16 h at room temperature. The pyridine was removed
under vacuum, the residue was dissolved in ethyl acetate, washed
with water and brine then dried (Na2SO4,), filtered, and concen-
trated and the residue purified by column chromatography.
4.2.6. 17b-(40-Methylbenzene)sulfonamide-1,3,5(10)-estratrien-
3-ol (6)
4.2.10. 17b-(40-Methylbenzylsulfonamide-1,3,5(10)-estratrien-
3-ol (15)
Purification was achieved using flash chromatography (100%
chloroform then methanol/chloroform, 1:9) which provided 6 as
Purification was achieved using flash chromatography (100%
chloroform then methanol/chloroform, 1:9) which provided 15 as
a white solid (38%). Mp 140–141 °C; 1H NMR (CDCl3, 300 MHz) d
7.27 (d, J = 7.9 Hz, 2H, ArH-a), 7.17 (d, J = 7.9 Hz, 2H, ArH-b), 7.11
(d, J = 8.4 Hz, 1H, H-1), 6.60 (dd, J = 8.4 and 2.5 Hz, 1H, H-2), 6.53
(d, J = 2.2 Hz, 1H, H-4), 4.66 (br s, 1H, Ar-OH), 4.18 (AB system,
2H, J = 13.9 and 13.9 Hz, 2H, Ar-CH2), 3.99 (d, J = 9.2 Hz, 1H, NH),
3.27 (q, J = 8.9 Hz, 1H, H-17), 2.78 (m, 2H), 2.34 (s, 3H, Ar-CH3),
2.30–2.25 (m, 1H), 2.15–2.10 (m, 2H), 1.95–1.69 (m, 3H), 1.43–
1.13 (m, 7H), 0.65 (s, 3H, CH3, H-18); 13C NMR (CDCl3, 75 MHz) d
a white solid (33%). Mp 179–180 °C (lit. 184–185 °C)27 1H NMR
;
(CDCl3, 300 MHz), d 7.75 (d, J = 8.2 Hz, 2H, ArH-a), 7.28 (d,
J = 8.0 Hz, 2H, ArH-b), 7.08 (d, J = 8.4 Hz, 1H, H-1), 6.58 (dd,
J = 8.3 and 2.7 Hz, 1H, H-2), 6.52 (d, J = 2.6 Hz, 1H, H-4), 4.73 (br
s, 1H, Ar-OH), 4. 50 (d, J = 9.2 Hz, 1H, NH), 3.13 (q, J = 8.9 Hz, 1H,
H-17), 2.76 (m, 2H), 2.41 (s, 3H, C6H4–CH3), 2.23–2.10 (m, 2H),
1.83–1.71 (m, 3H), 1.62–1.60 (m, 1H), 1.39–1.08 (m, 7H), 0.68 (s,
3H, CH3, H-18).

1540
Y. A. Mostafa, S. D. Taylor / Bioorg. Med. Chem. 20 (2012) 1535–1544
153.4 (C-3), 138.6 (C–CH2SO2NH), 138.1 (C-5), 132.4 (C-6), 130.6
(2ArCH), 129.4 (2ArCH), 126.5 (C-1), 126.4 (ArCH), 115.2 (C-4),
112.7 (C-2), 63.8 (C-17), 59.3 (CH2SO2NH), 51.1 (C-14), 43.7 (CH),
42.9 (C-13), 38.9 (CH), 36.5 (CH2), 30.0 (CH2), 29.5 (CH2), 27.1
(CH2), 26.1 (CH2), 23.1 (CH2), 21.2 (C6H4–CH3), 11.8 (CH3, C-18);
LRMS (ESI+) m/z (%) 440 (M+H, 31), 377 (28), 376 (100), 270 (28);
HRMS (ESI+) calcd for C26H34NO3S (M+H)+ 440.2259; found
440.2265.
35.8 (CH2–CH2–CH2–CH2–CH3), 31.3 (CH2–CH2–CH2–CH2–CH3),
30.7 (CH2–CH2–CH2–CH2–CH3), 29.5 (2CH2), 27.1 (CH2), 26.0
(CH2), 23.1 (CH2), 22.4 (CH2–CH2–CH2–CH2–CH3), 13.9 (CH2–CH2–
CH2–CH2–CH3), 11.8 (CH3, C-18); LRMS (ESI+) m/z (%) 482 (M+H,
100), 255 (80); HRMS (ESI+) calcd for C29H40NO3S (M+H)+
482.2729; found 482.2721.
4.2.14. 17b-(40-iso-Propylbenzene)sulfonamide-1,3,5(10)-
estratrien-3-ol (19)
4.2.11. 17b-(40-n-Propylbenzene)sulfonamide-1,3,5(10)-
estratrien-3-ol (16)
Purification was achieved using flash chromatography (100%
chloroform then methanol/chloroform, 1:9) which provided 19 as
a white solid (43%). Mp 206–207 °C; 1H NMR (CDCl3, 300 MHz) d
7.78 (d, J = 8.4 Hz, 2H, ArH-a), 7.33 (d, J = 8.3 Hz, 2H, ArH-b), 7.08
(d, J = 8.4 Hz, 1H, H-1), 6.58 (dd, J = 8.4 and 2.7 Hz, 1H, H-2), 6.52
(d, J = 2.6 Hz, 1H, H-4), 4.61 (br s, 1H, Ar-OH), 4.42 (d, J = 9.2 Hz,
1H, NH), 3.15 (q, J = 8.8 Hz, 1H, H-17), 3.01–2.92 (m, 1H), 2.76
(m, 2H), 2.20–2.11 (m, 2H), 1.82–1.61 (m, 4H), 1.38–1.10 (m over-
lapping d of –CH(CH3)2 with J = 7.0 Hz, 13H), 0.68 (s, 3H, CH3, H-
18); 13C NMR (CDCl3, 75 MHz) d 154.0 (C-i-propyl), 153.3 (C-3),
138.4 (C–SO2NH–), 138.1 (C-5), 132.4 (C-6), 127.1 (4ArCH-b & a
overlapping), 126.5 (C-1), 115.2 (C-4), 112.7 (C-2), 63.3 (C-17),
51.1 (C-14), 43.7 (CH), 42.9 (C-13), 38.8 (CH), 36.3 (CH2), 34.1
(CH(CH3)2), 29.5 (2CH2), 27.1 (CH2), 26.0 (CH2), 23.7 (2CH3,
CH(CH3)2), 23.1 (CH2), 11.8 (CH3, C-18); LRMS (EI) m/z (%) 453
(M+, 100), 270 (90), 253 (30); HRMS (ESI+) calcd for C27H36NO3S
(M+H)+ 454.2416; found 454.2403.
Purification was achieved using flash chromatography (100%
chloroform then methanol/chloroform, 1:9) which provided 16 as
a white solid (27%). Mp 217–218 °C; 1H NMR (CDCl3, 300 MHz) d
7.76 (d, J = 8.1 Hz, 2H, ArH-a), 7.27 (d, J = 8.1 Hz, 2H, ArH-b), 7.08
(d, J = 8.4 Hz, 1H, H-1), 6.58 (d, J = 8.4 Hz, 1H, H-2), 6.52 (br s, 1H,
H-4), 4.59 (br s, 1H, Ar-OH), 4.39 (d, J = 9.2 Hz, 1H, NH), 3.15 (q,
J = 8.7 Hz, 1H, H-17), 2.76 (m, 2H), 2.64 (t, J = 7.6 Hz, 2H, CH2–
CH2–CH3), 2.20–2.07 (m, 2H), 1.89–1.61 (m, 6H), 1.42–1.06 (m,
7H), 0.92 (t, J = 7.3 Hz, 3H, CH2–CH2–CH3), 0.68 (s, 3H, CH3, H-
18); 13C NMR (CDCl3, 75 MHz) d 153.3 (C-3), 147.9 (C-propyl),
138.3 (C–SO2NH–), 138.0 (C-5), 132.4 (C-6), 129.0 (2ArCH-b),
127.1 (2ArCH-a), 126.5 (C-1), 115.2 (C-4), 112.7 (C-2), 63.3 (C-
17), 51.1 (C-14), 43.7 (CH), 42.9 (C-13), 38.8 (CH), 37.8 (CH2–
CH2–CH3), 36.3 (CH2), 29.5 (2CH2), 27.1 (CH2), 26.0 (CH2), 24.2
(CH2–CH2–CH3), 23.1 (CH2), 13.6 (CH2–CH2–CH3), 11.8 (CH3, C-
18); LRMS (ESI+) m/z (%) 454 (M+H, 72), 256 (20), 255 (100); HRMS
(ESI+) calcd for C27H36NO3S (M+H)+ 454.2416; found 454.2410.
4.2.15. 17b-(40-t-Butylbenzene)sulfonamide-1,3,5(10)-
estratrien-3-ol (20)
4.2.12. 17b-(40-n-Butylbenzene)sulfonamide-1,3,5(10)-
estratrien-3-ol (17)
Purification was achieved by flash chromatography (100% chlo-
roform then methanol/chloroform, 1:9) which provided 20 as a
white solid (53%). Mp 218–219 °C; 1H NMR (CDCl3, 300 MHz) d
7.78 (d, J = 8.4 Hz, 2H, ArH-a), 7.48 (d, J = 8.5 Hz, 2H, ArH-b), 7.09
(d, J = 8.4 Hz, 1H, H-1), 6.58 (dd, J = 8.3 and 2.5 Hz, 1H, H-2), 6.52
(d, J = 2.5 Hz, 1H, H-4), 4.56 (br s, 1H, Ar-OH), 4.32 (d, J = 9.2 Hz,
1H, NH), 3.15 (q, J = 8.7 Hz, 1H, H-17), 2.76 (m, 2H), 2.15–2.03
(m, 2H), 1.86–1.61 (m, 4H), 1.39–1.11 (m, 16H), 0.68 (s, 3H, CH3,
H-18); 13C NMR (CDCl3, 75 MHz) d 156.3 (C-t-butyl), 153.3 (C-3),
138.1 (C–SO2NH–), 138.0 (C-5), 132.5 (C-6), 126.9 (2ArCH-b),
126.5 (C-1), 125.9 (2ArCH-a), 115.2 (C-4), 112.7 (C-2), 63.3 (C-
17), 51.1 (C-14), 43.7 (CH), 42.9 (C-13), 38.8 (CH), 36.3 (CH2),
35.1 (C(CH3)3), 31.1 (C(CH3)3), 29.5 (2CH2), 27.1 (CH2), 26.0 (CH2),
23.1 (CH2), 11.8 (CH3, C-18); LRMS (EI) m/z (%) 467 (M+, 91), 270
(100), 253 (32); HRMS (ESI+) calcd for C28H38NO3S (M+H)+
468.2572; found 468.2566.
Purification was achieved using flash chromatography (100%
chloroform then methanol/chloroform, 1:9) which provided 17 as
a white solid (56%). Mp 221–222 °C; 1H NMR (CDCl3, 300 MHz) d
7.76 (d, J = 8.3 Hz, 2H, ArH-a), 7.28 (d, J = 8.3 Hz, 2H, ArH-b), 7.09
(d, J = 8.4 Hz, 1H, H-1), 6.58 (dd, J = 8.3 and 2.6 Hz, 1H, H-2), 6.52
(d, J = 2.6 Hz, 1H, H-4), 4.50 (br s, 1H, Ar-OH), 4.32 (d, J = 9.2 Hz,
1H, NH), 3.15 (q, J = 8.9 Hz, 1H, H-17), 2.76 (m, 2H), 2.67 (t,
J = 7.5 Hz, 2H, CH2–CH2–CH2–CH3), 2.20–2.11 (m, 2H), 1.83–1.58
(m, 6H), 1.37–1.10 (m, 9H), 0.92 (t, J = 7.3 Hz, 3H, CH2–CH2–CH2–
CH3), 0.68 (s, 3H, CH3, H-18); 13C NMR (CDCl3, 75 MHz) d 153.3
(C-3), 148.1 (C-Butyl), 138.3 (C–SO2NH–), 138.1 (C-5), 132.5
(C-6), 129.0 (2ArCH-b), 127.1 (2ArCH-a), 126.5 (C-1), 115.2 (C-4),
112.7 (C-2), 63.3 (C-17), 51.1 (C-14), 43.7 (CH), 42.9 (C-13), 38.8
(CH), 36.3 (CH2), 35.5 (CH2–CH2–CH2–CH3), 33.2 (CH2–CH2–CH2–
CH3), 29.5 (2CH2), 27.1 (CH2), 26.0 (CH2), 23.1 (CH2), 22.2 (CH2–
CH2–CH2–CH3), 13.9 (CH2–CH2–CH2–CH3), 11.8 (CH3, C-18); LRMS
(ESI+) m/z (%) 468 (M+H, 100), 255 (74), 219 (29), 152 (31); HRMS
(ESI+) calcd for C28H38NO3S (M+H)+ 468.2572; found 468.2559.
4.2.16. 17b-(40-Phenylbenzene)sulfonamide-1,3,5(10)-
estratrien-3-ol (21)
Purification was achieved using flash chromatography (100%
chloroform then methanol/chloroform, 1:9) which provided 21 as
a white solid (31%). Mp 223–224 °C; 1H NMR (CDCl3, 300 MHz) d
7.92 (d, J = 8.4 Hz, 2H, ArH-a), 7.70 (d, J = 8.3 Hz, 2H, ArH-b), 7.62
(dd overlapping, J = 8.4 and 1.5 Hz, 2H, ArH-a0), 7.50–7.38 (m, 3H,
ArH-b0 and c0), 7.09 (d, J = 8.3 Hz, 1H, H-1), 6.58 (dd, J = 8.4 and
2.4 Hz, 1H, H-2), 6.52 (br s, 1H, H-4), 4.45 (br s, 1H, Ar-OH), 4.40
(d, J = 9.3 Hz, 1H, NH), 3.20 (q, J = 8.5 Hz, 1H, H-17), 2.76 (m, 2H),
2.23–2.12 (m, 2H), 1.91–1.63 (m, 2H), 1.40–1.12 (m, 7H), 0.70 (s,
3H, CH3, H-18); 13C NMR (CDCl3, 75 MHz) d 153.3 (C-3), 145.4 (C-
4.2.13. 17b-(40-n-Pentylbenzene)sulfonamide-1,3,5(10)-estratri
en-3-ol (18)
Purification was achieved using flash chromatography (100%
chloroform then methanol/chloroform, 1:4), which provided 18
as
a
white solid (21%). Mp 168–169 °C; 1H NMR (CDCl3,
300 MHz) d 7.76 (d, J = 7.8 Hz, 2H, ArH-a), 7.28 (d, J = 8.0 Hz, 2H,
ArH-b), 7.09 (d, J = 8.4 Hz, 1H, H-1), 6.58 (dd, J = 8.2 and 2.2 Hz,
1H, H-2), 6.52 (br s, 1H, H-4), 4.50 (br s, 1H, Ar-OH), 4.35 (d,
J = 9.2 Hz, 1H, NH), 3.15 (q, J = 8.7 Hz, 1H, H-17), 2.76 (m, 2H),
2.66 (t, J = 7.4 Hz, 2H, CH2–CH2–CH2–CH2–CH3), 2.21–2.11 (m,
2H), 1.85–1.80 (m, 2H), 1.77–1.59 (m, 4H), 1.38–1.09 (m, 11H),
0.87 (t, J = 6.3 Hz, 3H, CH2–CH2–CH2–CH2–CH3), 0.68 (s, 3H, CH3,
H-18); 13C NMR (CDCl3, 75 MHz) d 153.3 (C-3), 148.2 (C-pentyl),
138.3 (C–SO2NH–), 138.1 (C-5), 132.5 (C-6), 129.0 (2ArCH-b),
127.1 (2ArCH-a), 126.5 (C-1), 115.2 (C-4), 112.7 (C-2), 63.3 (C-
17), 51.1 (C-14), 43.7 (CH), 42.9 (C-13), 38.8 (CH), 36.3 (CH2),
0
Phenyl), 139.7 (C–SO2NH–), 139.3 (C-C1 -Phenyl), 138.1 (C-5),
132.5 (C-6), 129.0 (2ArCH), 128.5 (ArCH), 127.6 (4ArCH overlap-
ping), 127.3 (2ArCH), 126.5 (C-1), 115.2 (C-4), 112.7 (C-2), 63.4
(C-17), 51.1 (C-14), 43.7 (CH), 42.9 (C-13), 38.8 (CH), 36.3 (CH2),
29.5 (2CH2), 27.1 (CH2), 26.0 (CH2), 23.1 (CH2), 11.8 (CH3, C-18);
LRMS (ESI+) m/z (%) 488 (M+H, 17), 391 (47), 323 (40), 219 (100),
173 (48); HRMS (ESI+) calcd for C30H34NO3S (M+H)+ 488.2259;
found 488.2262.

Y. A. Mostafa, S. D. Taylor / Bioorg. Med. Chem. 20 (2012) 1535–1544
1541
4.2.17. 17b-(40-Phenoxybenzene)sulfonamide-1,3,5(10)-
estratrien-3-ol (22)
2.6 Hz, 1H, H-2), 6.52 (d, J = 2.5 Hz, 1H, H-4), 4.76 (s, 1H, Ar-OH),
4.63 (d, J = 9.4 Hz, 1H, NH), 3.17 (q, J = 8.8 Hz, 1H, H-17), 2.76 (m,
2H), 2.23–2.12 (m, 2H), 1.84–1.65 (m, 4H), 1.39–1.13 (m, 7H),
0.69 (s, 3H, CH3, H-18); 13C NMR (CDCl3, 75 MHz) d 153.4 (C-3),
143.0 (C–SO2NH–), 138.0 (C-5), 135.5 (ArCH-c), 132.3 (C-6), 130.6
(ArCH-b), 130.0 (ArCH-d), 126.5 (C-1), 125.5 (ArCH-a), 122.9 (C-
Br), 115.2 (C-4), 112.7 (C-2), 63.5 (C-17), 51.0 (C-14), 43.7 (CH),
42.9 (C-13), 38.8 (CH), 36.3 (CH2), 29.4 (2CH2), 27.1 (CH2), 26.0
(CH2), 23.1 (CH2), 11.8 (CH3, C-18); LRMS (ESIꢀ) m/z (%) 491
(M+2, 27), 490 (MꢀH+2, 98), 489 (M+, 28), 488 (MꢀH, 97), 255
(100), HRMS (ESIꢀ) calcd for C24H27BrNO3S (MꢀH)ꢀ 488.0895;
found 488.0908.
Purification was achieved using flash chromatography (100%
chloroform then methanol/chloroform, 2:3) which provided 22 as
a white solid (38%). Mp 184–185 °C; 1H NMR (CDCl3, 300 MHz) d
7.81 (d, J = 8.5 Hz, 2H, ArH-a), 7.39 (dd overlapping, J = 7.7 and
7.7 Hz, 2H, ArH-b0), 7.18 (d, J = 7.1 Hz, 1H, ArH-c0), 7.06 (d overlap-
ping dd, J = 8.4, 8.2 and 8.6 Hz respectively, 5H, H-1 and 4ArH-a0 &
b), 6.58 (d, J = 8.5 Hz, 1H, H-2), 6.52 (br s, 1H, H-4), 4.49 (br s, 1H,
Ar-OH), 4.35 (d, J = 9.3 Hz, 1H, NH), 3.15 (q, J = 8.7 Hz, 1H, H-17),
2.76 (m, 2H), 2.23–2.09 (m, 2H), 1.90–1.61 (m, 2H), 1.40–1.09
(m, 7H), 0.69 (s, 3H, CH3, H-18); 13C NMR (CDCl3, 75 MHz) d
161.3 (C-Phenyl), 155.3 (O-C-Phenyl), 153.3 (C-3), 138.1 (C-5),
134.8 (C–SO2NH–), 132.4 (C-6), 130.1 (2ArCH-b0), 129.3 (2ArCH-
a), 126.5 (C-1), 124.8 (ArCH-c0), 120.1 (2ArCH-b), 117.7 (2Ar-CH-
a0), 115.2 (C-4), 112.7 (C-2), 63.3 (C-17), 51.1 (C-14), 43.8 (CH),
42.9 (C-13), 38.8 (CH), 36.3 (CH2), 29.5 (2CH2), 27.1 (CH2), 26.1
(CH2), 23.2 (CH2), 11.8 (CH3, C-18); LRMS (ESI+) m/z (%) 504
(M+H, 100), 256 (15), 255 (75); HRMS (ESI+) calcd for C30H34NO4S
(M+H)+ 504.2209; found 504.2207.
4.2.21. 17b-(40-Bromobenzene)sulfonamide-1,3,5(10)-
estratrien-3-ol (26)
Purification was achieved using flash chromatography (ethyl
acetate/hexane, 1:9) which provided 26 as a white solid (78%).
Mp 115–116 °C; 1H NMR (CDCl3, 300 MHz) d 7.74 (d, J = 8.7 Hz,
2H, ArH-a), 7.64 (d, J = 8.7 Hz, 2H, ArH-b), 7.09 (d, J = 8.4 Hz, 1H,
H-1), 6.58 (dd, J = 8.5 and 2.5 Hz, 1H, H-2), 6.52 (d, J = 2.5 Hz, 1H,
H-4), 4.54 (br s, 1H, Ar-OH), 4.42 (d, J = 9.4 Hz, 1H, NH), 3.15 (q,
J = 8.7 Hz, 1H, H-17), 2.76 (m, 2H), 2.24–2.08 (m, 2H), 1.88–1.60
(m, 4H), 1.40–1.12 (m, 7H), 0.68 (s, 3H, CH3, H-18); 13C NMR
(CDCl3, 75 MHz) d 153.3 (C-3), 140.2 (C–SO2NH–), 138.1 (C-5),
132.3 (C-6), 132.2 (2ArCH), 128.6 (2ArCH), 127.4 (C-Br), 126.5 (C-
1), 115.2 (C-4), 112.7 (C-2), 63.4 (C-17), 51.1 (C-14), 43.7 (CH),
43.0 (C-13), 38.8 (CH), 36.3 (CH2), 29.5 (CH2), 29.4 (CH2), 27.1
(CH2), 26.0 (CH2), 23.1 (CH2), 11.8 (CH3, C-18); LRMS (ESI+) m/z
(%) 492 (M+H+2, 75), 490 (M+H, 72), 256 (20), 255 (100); HRMS
(ESI+) calcd for C24H29BrNO3S (M+H)+ 490.1052; found 490.1046.
4.2.18. 17b-20-Naphthylsulfonamide-1,3,5(10)-estratrien-3-ol
(23)
Purification was achieved using flash chromatography (ethyl
acetate/hexane, 2:3) which provided 23 as a white solid (25%).
Mp 136–137 °C; 1H NMR (CDCl3, 300 MHz) d 8.45 (br s, 1H, ArH),
7.96–7.82 (m, 4H, ArH), 7.66–7.57 (m, 2H, ArH), 7.06 (d,
J = 8.3 Hz, 1H, H-1), 6.58 (d, J = 8.4 Hz, 1H, H-2), 6.51 (br s, 1H, H-
4), 4.54 (s overlapping d, J = 8.8 Hz, 2H, Ar-OH and NH), 3.20 (q,
J = 8.6 Hz, 1H, H-17), 2.74 (m, 2H), 2.18–2.02 (m, 2H), 1.83–1.73
(m, 2H), 1.60–1.55 (m, 1H), 1.41–1.12 (m, 7H), 0.70 (s, 3H, CH3,
H-18); 13C NMR (CDCl3, 75 MHz) d 153.3 (C-3), 138.1 (C-5),
137.8, 134.7, 132.5 (C-6), 132.1, 129.4, 129.2, 128.7, 128.3, 127.9,
127.5, 126.5 (C-1), 122.4, 115.1 (C-4), 112.6 (C-2), 63.4 (C-17),
51.1 (C-14), 43.7 (CH), 42.9 (C-13), 38.8 (CH), 36.3 (CH2), 29.5
(2CH2), 27.1 (CH2), 26 (CH2), 23.1 (CH2), 11.8 (CH3, C-18); LRMS
(ESI+) m/z (%) 462 (M+H, 100), 256 (20), 255 (97); HRMS (ESI+)
calcd for C28H32NO3S (M+H)+ 462.2103; found 462.2102.
4.2.22. 17b-(30-Chlorobenzene)sulfonamide-1,3,5(10)-
estratrien-3-ol (27)
Purificationwas achievedusingflashchromatography(ethylace-
tate/hexane, 1:9) which provided 27 as a white solid (73%). Mp 186–
187 °C; 1H NMR (CDCl3, 300 MHz) d 7.87 (dd overlapping, J = 1.8 and
1.7 Hz, 1H, ArH-d), 7.75 (ddd, J = 7.7, 1.6, and 1.2 Hz, 1H, ArH-a), 7.53
(dddd, J = 8.02, 2.0, 1.9, and 1.2 Hz, 1H, ArH-c), 7.43 (dd overlapping,
J = 7.9 and 7.9 Hz, 1H, ArH-b), 7.09 (d, J = 8.4 Hz, 1H, H-1), 6.59 (dd,
J = 8.4 and 2.7 Hz, 1H, H-2), 6.52 (d, J = 2.6 Hz, 1H, H-4), 4.53 (s, 1H,
Ar-OH), 4.50 (d,, J = 9.5 Hz, 1H, NH), 3.18 (q, J = 8.9 Hz, 1H, H-17),
2.76 (m, 2H), 2.24–2.12 (m, 2H), 1.85–1.69 (m, 4H), 1.40–1.13 (m,
7H), 0.69 (s, 3H, CH3, H-18); 13C NMR (CDCl3, 75 MHz) d 153.3 (C-
3), 142.9 (C–SO2NH–), 138.0 (C-5), 135.1 (C-6), 132.6 (ArCH-c),
132.3 (C–Cl), 130.3 (ArCH-b), 127.2 (ArCH-d), 126.5 (C-1), 125.1
(ArCH-a), 115.2 (C-4), 112.6 (C-2), 63.5 (C-17), 51 (C-14), 43.7
(CH), 42.9 (C-13), 38.8 (CH), 36.3 (CH2), 29.4 (2CH2), 27.1 (CH2),
26.0 (CH2), 23.1 (CH2), 11.8 (CH3, C-18); LRMS (EI) m/z (%) 447
(M+2, 40), 445 (M+, 100), 270 (43), 253 (25), 213 (30), HRMS (EI)
calcd for C24H28ClNO3S 445.1478; found 445.1474.
4.2.19. 17b-(20-Bromobenzene)sulfonamide-1,3,5(10)-estratrien
-3-ol (24)
Purification was achieved using flash chromatography (ethyl
acetate/hexane, 1:4) which provided 24 as a white solid (67%):
Mp 225–226 °C; 1H NMR (CDCl3, 300 MHz) d 8.14 (dd, J = 8.9 and
1.3 Hz 1H, ArH-a), 7.72 (d, J = 7.4 Hz, 1H, ArH-d), 7.42 (m, 2H,
ArH-c & b), 7.07 (d, J = 8.4 Hz, 1H, H-1), 6.58 (d, J = 8.3 Hz, 1H, H-
2), 6.52 (br s, 1H, H-4), 5.06 (d, J = 8.9 Hz, 1H, NH), 4.64 (s, 1H,
Ar-OH), 3.12 (q, J = 8.8 Hz, 1H, H-17), 2.75 (m, 2H), 2.20–2.05 (m,
2H), 1.80–1.58 (m, 6H), 1.39–0.82 (m, 6H), 0.74 (s, 3H, CH3, H-
18); 13C NMR (CDCl3, 75 MHz) d 153.3 (C-3), 139.9 (C–SO2NH–),
138.0 (C-5), 134.9 (ArCH-c), 133.5 (ArCH-a), 132.3 (C-6), 131.4
(ArCH-d), 127.8 (ArCH-b), 126.5 (C-1), 119.9 (C-Br), 115.2 (C-4),
112.7 (C-2), 63.7 (C-17), 51 (C-14), 43.7 (CH), 43.0 (C-13), 38.7
(CH), 36.2 (CH2), 29.4 (CH2), 28.7 (CH2), 27.1 (CH2), 26 (CH2),
23.1 (CH2), 11.9 (CH3, C-18); LRMS (ESI+) m/z (%) 492 (M+H+2,
28), 491 (M+2, 9), 490 (M+H, 28), 256 (20), 255 (100); HRMS
(ESI+) calcd for C24H29BrNO3S (M+H)+ 490.1052; found 490.1053.
4.2.23. 17b-(40-Chlorobenzene)sulfonamide-1,3,5(10)-
estratrien-3-ol (28)
Purification was achieved using flash chromatography (ethyl
acetate/hexane, 1:9) which provided 28 as a white solid (69%).
Mp 124–125 °C; 1H NMR (CDCl3, 300 MHz) d 7.82 (d, J = 8.4 Hz,
2H, ArH-a), 7.45 (d, J = 8.4 Hz, 2H, ArH-b), 7.07 (d, J = 8.5 Hz, 1H,
H-1), 6.60 (d, J = 8.4 Hz, 1H, H-2), 6.53 (br s, 1H, H-4), 5.29 (br s,
1H, Ar-OH), 4.98 (d, J = 9.2 Hz, 1H, NH), 3.13 (q, J = 8.6 Hz, 1H, H-
17), 2.74 (m, 2H), 2.21–2.05 (m, 2H), 1.87–1.60 (m, 4H), 1.42–
1.07 (m, 7H), 0.67 (s, 3H, CH3, H-18); 13C NMR (CDCl3, 75 MHz) d
153.3 (C-3), 139.7 (C–SO2NH–), 138.9 (C–Cl), 138.0 (C-5), 132.3
(C-6), 129.3 (2ArCH-b), 128.5 (2ArCH-a), 126.5 (C-1), 115.2 (C-4),
112.7 (C-2), 63.4 (C-17), 51.1 (C-14), 43.7 (CH), 43.0 (C-13), 38.8
(CH), 36.3 (CH2), 29.4 (2CH2), 27.1 (CH2), 26.0 (CH2), 23.1 (CH2),
11.8 (CH3, C-18); LRMS (ESI+) m/z (%) 448 (M+H+2, 38), 447
4.2.20. 17b-(30-Bromobenzene)sulfonamide-1,3,5(10)-
estratrien-3-ol (25)
Purification was achieved using flash chromatography (ethyl
acetate/hexane, 1:9) which provided 25 as a white solid (82%).
Mp 182–183 °C; 1H NMR (CDCl3, 300 MHz) d 8.03 (dd overlapping,
J = 1.7 and 1.6 Hz, 1H, ArH-d), 7.80 (d, J = 7.9 Hz, 1H, ArH-a), 7.67
(dd, J = 7.7 and 6.9 Hz, 1H, ArH-c), 7.37 (dd, J = 7.9 and 7.9 Hz,
1H, ArH-b), 7.09 (d, J = 8.4 Hz, 1H, H-1), 6.60 (dd, J = 8.3 and

1542
Y. A. Mostafa, S. D. Taylor / Bioorg. Med. Chem. 20 (2012) 1535–1544
(M+2, 30), 446 (M+H, 100), 255 (18), 239 (38); HRMS (ESI+) calcd
for C24H29ClNO3S (M+H)+ 446.1557; found 446.1542.
Mp 140–141 °C; 1H NMR (CDCl3, 300 MHz) d 7.89 (m, 2H, ArH-a),
7.16 (dd overlapping, J = 8.5 and 8.5 Hz, 2H, ArH-b), 7.08 (d,
J = 8.4 Hz, 1H, H-1), 6.59 (dd, J = 8.4 and 2.5 Hz, 1H, H-2), 6.53 (d,
J = 2.5 Hz, 1H, H-4), 4.89 (br s, 1H, Ar-OH), 4.71 (d, J = 9.2 Hz, 1H,
NH), 3.13 (q, J = 8.8 Hz, 1H, H-17), 2.75 (m, 2H), 2.22–2.10 (m,
2H), 1.85–1.61 (m, 4H), 1.38–1.09 (m, 7H), 0.68 (s, 3H, CH3, H-
18); 13C NMR (CDCl3, 75 MHz) d 164.9 (d, J = 253.0 Hz, C–F),
153.4 (C-3), 138.0 (C-5), 137.2 (d, J = 3.2 Hz, C–SO2NH–), 132.3
(C-6), 129.7 (d, J = 9.9 Hz, 2ArCH-a), 126.5 (C-1), 116.1 (d,
J = 22.4 Hz, 2ArCH-b), 115.2 (C-4), 112.7 (C-2), 63.4 (C-17), 51.1
(C-14), 43.7 (CH), 43.0 (C-13), 38.8 (CH), 36.3 (CH2), 29.4 (2CH2),
27.1 (CH2), 26.0 (CH2), 23.1 (CH2), 11.8 (CH3, C-18); 19F NMR
(CDCl3, 282 MHz) d -105; LRMS (ESI+) m/z (%) 430 (M+H, 100),
255 (13), 223 (15); HRMS (ESI+) calcd for C24H29FNO3S (M+H)+
430.1852; found 430.1847.
4.2.24. 17b-(30-Nitrobenzene)sulfonamide-1,3,5(10)-estratrien-
3-ol (29)
Purification was achieved using flash chromatography (ethyl
acetate/hexane, 3:2) which provided 29 as a yellow solid (49%).
Mp 200–201 °C; 1H NMR (CDCl3, 300 MHz) d 8.72 (br s, 1H, ArH-
d), 8.41 (m, 1H, ArH-c), 8.20 (m, 1H, ArH-a), 7.72 (m, 1H, ArH-b),
7.09 (d, J = 8.4 Hz, 1H, H-1), 6.58 (dd, J = 8.3 and 2.4 Hz, 1H, H-2),
6.52 (br s, 1H, H-4), 4.53 (d,, J = 9.5 Hz, 1H, NH), 4.45 (s, 1H, Ar-
OH), 3.25 (q, J = 8.6 Hz, 1H, H-17), 2.76 (m, 2H), 2.24–2.13 (m,
2H), 1.92–1.66 (m, 4H), 1.40–1.14 (m, 7H), 0.71 (s, 3H, CH3, H-
18); 13C NMR (CDCl3, 75 MHz) d 153.3 (C-3), 148.2 (C–NO2),
143.5 (C–SO2NH–), 138 (C-5), 132.5 (ArCH), 132.2 (C-6), 130.4
(ArCH), 127 (ArCH), 126.5 (C-1), 122.3 (ArCH), 115.2 (C-4), 112.7
(C-2), 63.6 (C-17), 51 (C-14), 43.7 (CH), 43 (C-13), 38.7 (CH), 36.3
(CH2), 29.4 (2CH2), 27.1 (CH2), 26 (CH2), 23.1 (CH2), 11.9 (CH3, C-
18); LRMS (EI) m/z (%) 456 (M+, 100), 270 (18), 213 (20); HRMS
(ESI+) calcd for C24H29N2O5S (M+H)+ 457.1797; found 457.1807.
4.2.28. 17b-(30-Trifluoromethylbenzene)sulfonamide-1,3,5(10)-
estratrien-3-ol (33)
Purification was achieved using flash chromatography (ethyl
acetate/hexane, 1:4) which provided 33 as a white solid (48%).
Mp 196–197 °C; 1H NMR (CDCl3, 300 MHz), d 8.14 (br s, 1H, ArH-
d), 8.07 (d, J = 7.9 Hz, 1H, ArH-a), 7.82 (d, J = 7.8 Hz, 1H, ArH-c),
7.65 (dd overlapping, J = 7.8 and 7.8 Hz, 1H, ArH-b), 7.09 (d,
J = 8.4 Hz, 1H, H-1), 6.59 (dd, J = 8.3 and 2.5 Hz, 1H, H-2), 6.52 (d,
J = 2.5 Hz, 1H, H-4), 4.47 (s overlapping d, J = 8.8 Hz, 2H, Ar-OH
and NH), 3.21 (q, J = 8.8 Hz, 1H, H-17), 2.76 (m, 2H), 2.22–2.12
(m, 2H), 1.86–1.65 (m, 4H), 1.39–1.12 (m, 7H), 0.69 (s, 3H, CH3,
H-18); 13C NMR (CDCl3, 75 MHz) d 153.4 (C-3), 142.5 (C–SO2NH–
), 138.0 (C-5), 132.3 (C-6), 131.7 (q, J = 33.2 Hz, C–CF3), 130.2 (d,
J = 1.0 Hz, ArCH), 129.8 (ArCH), 129.1 (q, J = 3.7 Hz,, ArCH), 126.5
(C-1), 124.1 (q, J = 3.9 Hz, ArCH), 123.2 (q, J = 271.3 Hz, C–CF3),
115.2 (C-4), 112.7 (C-2), 63.5 (C-17), 51.0 (C-14), 43.7 (CH), 42.9
(C-13), 38.8 (CH), 36.3 (CH2), 29.4 (2CH2), 27.1 (CH2), 26.0 (CH2),
23.1 (CH2), 11.8 (CH3, C-18); 19F NMR (CDCl3, 282 MHz), d -62.8;
LRMS (EI) m/z (%) 479 (M+, 100), 270 (21), 213 (22); HRMS (EI)
calcd for C25H28F3NO3S 479.1742; found 479.1732.
4.2.25. 17b-(30-Cyanobenzene)sulfonamide-1,3,5(10)-estratrien-
3-ol (30)
Purification was achieved using flash chromatography (ethyl
acetate/hexane, 2:3) which provided 30 as a white solid (53%).
Mp 127–128 °C; 1H NMR (CDCl3, 300 MHz) d 8.16 (s, 1H, ArH-a),
8.10 (d, J = 7.9 Hz, 1H, ArH-d), 7.84 (d, J = 7.8 Hz, 1H, ArH-c), 7.64
(dd, J = 7.7 and 7.9 Hz, 1H, ArH-b), 7.09 (d, J = 8.4 Hz, 1H, H-1),
6.59 (dd, J = 8.4 and 2.5 Hz, 1H, H-2), 6.53 (br s, 1H, H-4), 4.48–
4.46 (s and d overlapping, 2H, Ar-OH and NH), 3.20 (q, J = 8.9 Hz,
1H, H-17), 2.77 (m, 2H), 2.25–2.13 (m, 2H), 1.89–1.79 (m, 2H),
1.70–1.66 (m, 2H), 1.40–1.09 (m, 7H), 0.70 (s, 3H, CH3, H-18); 13C
NMR (CDCl3, 75 MHz) d 153.3 (C-3), 143.0 (C–SO2NH–), 138.0 (C-
5), 135.6 (ArCH-c), 132.2 (C-6), 130.9 (ArCH-a), 130.6 (ArCH-d),
130.1 (ArCH-b), 126.4 (C-1), 117.1 (CN), 115.2 (C-4), 113.6 (C–
CN), 112.7 (C-2), 63.5 (C-17), 51.0 (C-14), 43.7 (CH), 42.9 (C-13),
38.8 (CH), 36.3 (CH2), 29.6 (CH2), 29.6 (CH2), 27.0 (CH2), 26.0
(CH2), 23.1 (CH2), 11.8 (CH3, C-18); LRMS (EI) m/z (%) 436 (M+,
100), 253 (15), 213 (22); HRMS (EI) calcd for C25H28 N2O3S
436.1821; found 436.1811.
4.2.29. 17b-(40-Trifluoromethylbenzene)sulfonamide-1,3,5(10)-
estratrien-3-ol (34)
Purification was achieved using flash chromatography (ethyl
acetate/hexane, 1:1) which provided 34 as a white solid (34%).
Mp 138–139 °C; 1H NMR (CDCl3, 300 MHz) d 8.00 (d, J = 8.1 Hz,
2H, ArH-a), 7.76 (d, J = 8.0 Hz, 2H, ArH-b), 7.09 (d, J = 8.4 Hz, 1H,
H-1), 6.58 (d, J = 8.8 Hz, 1H, H-2), 6.53 (br s, 1H, H-4), 4.51 (d over-
lapping s, 2H, Ar-OH and NH), 3.20 (q, J = 8.6 Hz, 1H, H-17), 2.77
(m, 2H), 2.23–2.09 (m, 2H), 1.92–1.61 (m, 4H), 1.44–1.10 (m,
7H), 0.69 (s, 3H, CH3, H-18); 13C NMR (CDCl3, 75 MHz) d 153.4
(C-3), 144.8 (d, J = 1.2 Hz, C–SO2NH–), 138.0 (C-5), 134.2 (d,
J = 33.0 Hz, C–CF3), 132.3 (C-6), 127.5 (2ArCH-a), 126.5 (C-1),
126.2 (q, J = 3.7 Hz, 2ArCH-b), 123.0 (q, J = 271.2 Hz, C–CF3), 115.2
(C-4), 112.7 (C-2), 63.5 (C-17), 51.1 (C-14), 43.7 (CH), 43.0 (C-13),
38.8 (CH), 36.3 (CH2), 29.4 (2CH2), 27.1 (CH2), 26.0 (CH2), 23.1
(CH2), 11.8 (CH3, C-18); 19F NMR (CDCl3, 282 MHz) d ꢀ62.5; LRMS
(ESI+) m/z (%) 480 (M+H, 43), 256 (19), 255 (100); HRMS (ESI+)
calcd for C25H29F3NO3S (M+H)+ 480.1820; found 480.1813.
4.2.26. 17b-(30-Fluorobenzene)sulfonamide-1,3,5(10)-estratrien-
3-ol (31)
Purification was achieved using flash chromatography (ethyl
acetate/hexane, 3:7) which provided 31 as a white solid (65%).
Mp 182–183 °C; 1H NMR (CDCl3, 300 MHz) d 7.67 (d, J = 7.8 Hz,
1H, ArH-a), 7.58 (d, J = 8.2 Hz, 1H, ArH-d), 7.48 (m, 1H, ArH-b),
7.26 (m, overlapped with CDCl3, 1H, ArH-c), 7.09 (d, J = 8.4 Hz,
1H, H-1), 6.59 (dd, J = 8.4 and 2.5 Hz, 1H, H-2), 6.52 (d, J = 2.3 Hz,
1H, H-4), 4.60 (s, 1H, Ar-OH), 4.56 (d,, J = 9.3 Hz, 1H, NH), 3.18 (q,
J = 8.8 Hz, 1H, H-17), 2.76 (m, 2H), 2.22–2.12 (m, 2H), 1.88–1.63
(m, 4H), 1.39–1.12 (m, 7H), 0.69 (s, 3H, CH3, H-18); 13C NMR
(CDCl3, 75 MHz) d 162.3 (d, J = 250 Hz, C–F), 153.3 (C-3), 143.2 (d,
J = 6.6 Hz, C–SO2NH–), 138 (C-5), 132.3 (C-6), 130.8 (d, J = 7.6 Hz,
ArCH-b), 126.5 (C-1), 122.7 (d, J = 3.3 Hz, ArCH-a), 119.6 (d,
J = 21.0 Hz, ArCH-c), 115.2 (C-4), 114.4 (d, J = 24.1 Hz, ArCH-d),
112.7 (C-2), 63.5 (C-17), 51.0 (C-14), 43.7 (CH), 42.9 (C-13), 38.8
(CH), 36.3 (CH2), 29.4 (2CH2), 27.1 (CH2), 26.0 (CH2), 23.1 (CH2),
11.8 (CH3, C-18); 19F NMR (CDCl3, 282 MHz), d -109; LRMS (EI)
m/z (%) 429 (M+, 100), 270 (25), 213 (22); HRMS (EI) calcd for
4.2.30. 17b-(30-Methylbenzene)sulfonamide-1,3,5(10)-
estratrien-3-ol (35)
Purification was achieved using flash chromatography (ethyl
acetate/hexane, 1:9) which provided 35 as a white solid (43%). Mp
202–203 °C; 1H NMR (CDCl3, 300 MHz) d 7.67 (m, 2H, ArH-d & a),
7.36 (m, 2H, ArH-c & b), 7.09 (d, J = 8.5 Hz, 1H, H-1), 6.59 (dd,
J = 8.4 and 2.7 Hz, 1H, H-2), 6.51 (d, J = 2.5 Hz, 1H, H-4), 4.47 (s,
1H, Ar-OH), 4.34 (d, J = 9.3 Hz, 1H, NH), 3.16 (q, J = 8.7 Hz, 1H, H-
17), 2.76 (m, 2H), 2.4 (s, 3H, Ar-CH3), 2.23–2.11 (m, 2H), 1.82–1.72
(m, 4H), 1.35–1.12 (m, 7H), 0.68 (s, 3H, CH3, H-18); 13C NMR (CDCl3,
C24H28FNO3S 429.1774; found 429.1782.
4.2.27. 17b-(40-Fluorobenzene)sulfonamide-1,3,5(10)-
estratrien-3-ol (32)
Purification was achieved using flash chromatography (ethyl
acetate/hexane, 3:7) which provided 32 as a white solid (61%).

Y. A. Mostafa, S. D. Taylor / Bioorg. Med. Chem. 20 (2012) 1535–1544
1543
75 MHz) d 153.3 (C-3), 140.9 (C–SO2NH–), 139.1 (C–CH3), 138 (C-5),
133.2 (ArCH), 132.4 (C-6), 128.8 (ArCH), 127.4 (ArCH), 126.5 (C-1),
124.1 (ArCH), 115.2 (C-4), 112.7 (C-2), 63.3 (C-17), 51.1 (C-14),
43.7 (CH), 42.9 (C-13), 38.8 (CH), 36.3 (CH2), 29.5 (2CH2), 27.1
(CH2), 26.0 (CH2), 23.1 (CH2), 21.3 (Ar-CH3), 11.8 (CH3, C-18); LRMS
(EI) m/z (%) 425 (M+, 100), 270 (60), 253 (25), 213 (20); HRMS (EI)
calcd for C25H31NO3S 425.2025; found 425.2035.
164.2 (C(O)O), 148.4 (C-3), 138.3 (2C, C-5 and C-6), 135.8 (C–
C(O)NH–),133.3 (ArCH), 131.6 (q, J = 33 Hz, 2C, C–CF3), 130.6 (C–
C(O)O–), 130.1 (ArCH), 130.0 (d, J = 3.5 Hz, ArCH), 129.2 (d,
J = 3.4 Hz, 2ArCH), 127.9 (d, J = 3.5 Hz, ArCH), 126.9 (d, J = 3.7 Hz,
ArCH), 126.6 (C-1), 123.8 (q, J = 3.7 Hz, ArCH), 123.6 (q,
J = 270.9 Hz, 2C, C–CF3), 121.4 (C-4), 118.5 (C-2), 59.5 (C-17), 51.7
(C-14), 44.0 (C-13), 43.8 (CH), 38.6 (CH), 37.0 (CH2), 29.5 (CH2),
28.7 (CH2), 27.1 (CH2), 26.1 (CH2), 23.4 (CH2), 12.2 (CH3, C-18);
19F NMR (CDCl3, 282 MHz) d -62.5 (2CF3 overlapping); LRMS
(ESI+) m/z (%) 616 (M+H, 100); HRMS (ESI+) calcd for C34H32F6NO3
(M+H)+ 616.2286; found 616.2296.
4.2.31. 17b-(30-Methoxybenzene)sulfonamide-1,3,5(10)-estratri
en-3-ol (36)
Purification was achieved using flash chromatography (ethyl
acetate/hexane, 2:3) which provided 36 as a white solid (70%).
Mp 198–199 °C; 1H NMR (CDCl3, 300 MHz) d 7.43 (m, 3H, ArH-
a,b,d), 7.09 (m, 2H, ArH-c overlapping H-1), 6.58 (d, J = 8.3 Hz,
1H, H-2), 6.52 (s, 1H, H-4), 4.49 (s, 1H, Ar-OH), 4.39 (d, J = 9.1 Hz,
1H, NH), 3.85 (s, 3H, ArOCH3), 3.16 (pseudo t, 1H, H-17), 2.76 (m,
2H), 2.23–2.11 (m, 2H), 1.91–1.62 (m, 4H), 1.43–1.14 (m, 7H),
0.69 (s, 3H, CH3, H-18); 13C NMR (CDCl3, 75 MHz) d 159.8 (C–
OCH3), 153.3 (C-3), 142.3 (C–SO2NH–), 138.1 (C-5), 132.4 (C-6),
130 (ArCH), 126.5 (C-1), 119.2 (ArCH), 118.8 (ArCH), 115.2 (C-4),
112.7 (C-2), 111.8 (C-d), 63.4 (C-17), 55.6 (OCH3), 51.1 (C-14),
43.7 (CH), 42.9 (C-13), 38.8 (CH), 36.3 (CH2), 29.5 (2CH2), 27.1
(CH2), 26 (CH2), 23.1 (CH2), 11.8 (CH3, C-18); LRMS (EI) m/z (%)
441 (M+, 100), 270 (70), 253 (26), 213 (20); HRMS (EI) calcd for
4.2.34. 17b-(30-Trifluoromethyl)benzamido-estra-1,3,5(10)-
trien-3-ol (39)
To a stirred solution of compound 38 (120 mg, 0.27 mmol) in
methanol (15 mL), was added
a solution of K2CO3 (35 mg,
0.25 mmol) in H2O (120 L). The resultant solution was stirred
l
for 3 h, then diluted with water, neutralized with dil. HCl, and ex-
tracted with chloroform. The extract was then washed with water,
brine, filtered, dried with Na2SO4, and concentred. Purification was
achieved using flash chromatography (ethyl acetate/hexane, 1:9)
which provided 39 as a white solid (74%). Mp 135–136 °C; 1H
NMR (CDCl3, 300 MHz), d 7.99 (s, 1H, ArH-d), 7.92 (d, J = 7.7 Hz,
1H, ArH-a), 7.74 (d, J = 7.8 Hz, 1H, ArH-c), 7.56 (dd overlapping,
J = 7.7 and 7.8 Hz, 1H, ArH-b), 7.12 (d, J = 8.3 Hz, 1H, H-1), 6.61
(d, J = 8.3 Hz, 1H, H-2), 6.56 (br s, 1H, H-4), 6.01 (d, J = 8.7 Hz, 1H,
NH), 5.07 (br s, 1H, OH), 4.19 (q, J = 9.0 Hz, 1H, H-17), 2.80 (m,
2H), 2.29–2.21 (m, 3H), 1.89–1.85 (m, 3H), 1.58–1.39 (m, 7H),
0.81 (s, 3H, CH3, H-18); 13C NMR (CDCl3, 75 MHz) d 166.1
(C(O)NH), 153.3 (C-3), 138.1 (C-5), 135.7 (C–C(O)NH–), 132.4 (C-
6), 131.0 (d, J = 32.5 Hz, C–CF3), 130.0 (d, J = 1.3 Hz, ArCH), 129.2
(d, J = 2.4 Hz, ArCH), 127.9 (q, J = 3.7 Hz, ArCH), 126.5 (C-1), 123.8
(q, J = 3.8 Hz, ArCH), 123.7 (q, J = 271.0 Hz, C–CF3), 115.3 (C-4),
112.7 (C-2), 59.5 (C-17), 51.6 (C-14), 43.8 (C-13), 43.7 (CH), 38.9
(CH), 37.0 (CH2), 29.6 (CH2), 28.8 (CH2), 27.3 (CH2), 26.2 (CH2),
23.4 (CH2), 12.3 (CH3, C-18); 19F NMR (CDCl3, 282 MHz) d ꢀ62.9;
LRMS (ESI+) m/z (%) 444 (M+H, 100); HRMS (ESI+) calcd for
C25H31NO4S 441.1974; found 441.1979.
4.2.32. 17b-(30-Trifluoromethoxybenzene)sulfonamide-
1,3,5(10)-estratrien-3-ol (37)
Purification was achieved using flash chromatography (ethyl
acetate/hexane, 1:1) which provided 37 as a white solid (31%).
Mp 152–153 °C; 1H NMR (CDCl3, 300 MHz) d 7.84 (d, J = 7.8 Hz,
1H, ArH-a), 7.75 (br s, 1H, ArH-d), 7.55 (dd overlapped, J = 8.0
and 7.9 Hz, 1H, ArH-b), 7.41 (d, J = 8.1 Hz, 1H, ArH-c), 7.07 (d,
J = 8.4 Hz, 1H, H-1), 6.59 (d, J = 8.4 Hz, 1H, H-2), 6.53 (br s, 1H, H-
4), 4.98 (s, 1H, Ar-OH), 4.92 (d, J = 9.3 Hz, 1H, NH), 3.18 (q,
J = 8.9 Hz, 1H, H-17), 2.75 (m, 2H), 2.20–2.06 (m, 2H), 1.89–1.69
(m, 2H), 1.68–1.59 (m, 2H), 1.42–1.07 (m, 7H), 0.68 (s, 3H, CH3,
H-18); 13C NMR (CDCl3, 75 MHz)
d
153.4 (C-3), 149.3 (q,
C
26H29F3NO2 (M+H)+ 444.2150; found 444.2135.
J = 2.0 Hz, C–OCF3), 143.3 (C–SO2NH–), 138.0 (C-5), 132.3 (C-6),
130.7 (ArCH), 126.5 (C-1), 120.3 (q, J = 275.2 Hz, OCF3), 125.3
(ArCH), 124.9 (ArCH), 119.7 (d, J = 0.8 Hz, ArCH), 115.2 (C-4),
112.7 (C-2), 63.5 (C-17), 51.0 (C-14), 43.7 (CH), 42.9 (C-13), 38.8
(CH), 36.3 (CH2), 29.4 (CH2), 29.3 (CH2), 27.1 (CH2), 26.0 (CH2),
23.1 (CH2), 11.8 (CH3, C-18); 19F NMR (CDCl3, 282 MHz) d ꢀ57.6;
LRMS (ESI+) m/z (%) 496 (M+H, 32), 255 (41); HRMS (ESI+) calcd
for C25H29F3NO4S (M+H)+ 496.1769; found 496.1758.
4.3. Inhibition studies
4.3.1. IC50 determinations
Inhibitor solutions (20
0.1 M Tris–HCl pH 7.0 (1:1) were added to the wells of a 96-well
microtiter plate containing 20 L of a 2 mM 4-MUS solution in
0.1 M Tris–HCl, pH 7.0 and 140 L of 0.1 M Tris–HCl pH 7.0. The
reaction is initiated by the addition of 20 L of 100 nM STS in
20 mM Tris–HCl, pH 7.4, 0.1% Triton X-100 into to the well, yield-
ing a final concentration of 10 nM STS, 200 M 4-MUS (Km concen-
lL) of various concentrations in DMSO/
l
l
l
4.2.33. 17b-(30-Trifluoromethyl)benzamido-estra-1,3,5(10)-trien
-3-yl-(30-trifluoro-methyl)benzoate (38)
l
To
a
stirred solution of 17-amino-1,3,5(10)-estratrien-3-ol
tration) in 0.1 M Tris–HCl, pH 7.0, 0.01% Triton X-100, and 5%
DMSO. All reactions were performed in triplicate at 25 °C, and
STS activity was measured by monitoring for 10 min the produc-
tion of 4-MU using a spectrofluorimeter plate reader with excita-
tion and emission at 360 and 460 nM, respectively. The activity
of STS in the presence of inhibitor (Vi) was compared to the activity
of STS in the absence of inhibitor (Vo), and a percent activity was
calculated. IC50 was determined by plotting the percent activity
on a semi log graph against the log concentration of the inhibitor,
and fitted in Grafit from Erithacus Software (Surrey, UK) using the
equation: Vi = Vo/[1+([I]/IC50)S] + B where Vi = initial rate of reac-
tion at inhibitor concentration [I]; Vo = velocity in the absence of
inhibitor; B = background activity; s = slope factor equal Vo ꢀ B.
(150 mg, 0.55 mmol) in dry pyridine (3 mL) at 0 °C was added
the m-trifluoromethylbenzoyl chloride (230 mg, 1.10 mmol). The
reaction was stirred overnight at room temperature. The pyridine
was removed under vacuum, the residue was dissolved in chloro-
form, washed with water, dil. HCl, water, NaHCO3, water, and final-
ly brine then dried (Na2SO4,), filtered, and concentrated.
Purification was achieved using flash chromatography (ethyl ace-
tate/hexane, 3:7) which provided 38 as a white solid (57%). Mp
118–119 °C; 1H NMR (CDCl3, 300 MHz), d 8.43 (s, 1H, ArH), 8.35
(d, J = 8.1 Hz, 1H, ArH), 8.00 (s, 1H, ArH), 7.93 (d, J = 7.7 Hz, 1H,
ArH), 7.87 (d, J = 7.4 Hz, 1H, ArH), 7.74 (d, J = 7.6 Hz, 1H, ArH),
7.66–7.54 (m, 2H, ArH), 7.33 (d, J = 8.7 Hz, 1H, H-1), 6.94 (d over-
lapping br s, J = 8.9 Hz, 2H, H-2 and H-4, respectively), 5.97 (d,
J = 8.7 Hz, 1H, NH), 4.22 (q, J = 8.9 Hz, 1H, H-17), 2.89 (m, 2H),
2.33–2.26 (m, 3H), 1.94–1.82 (m, 3H), 1.63–1.40 (m, 7H), 0.83 (s,
3H, CH3, H-18); 13C NMR (CDCl3, 75 MHz) d 166.1 (C(O)NH),
4.3.2. Ki determination
A 2 mM stock solution of compound 25 was made in DMSO
(100%), from which dilutions 0.75, 0.50, and 0.25 lM were

1544
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l
l
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4-MUS concentration ranging between 83.3 and 500 lM, also, the
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Supplementary data
Supplementary data associated with this article can be found, in
the online version, at doi:10.1016/j.bmc.2011.12.036.
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