Bicyclic derivatives of the potent dual aromatase-steroid sulfatase inhibitor 2-bromo-4-{[(4-cyanophenyl)(4H-1,2,4-triazol-4-yl)amino]methyl} phenylsulfamate: Synthesis, SAR, crystal structure, and in vitro and in vivo activities

Article abstract of DOI:10.1002/cmdc.201000203

The design and synthesis of a series of bicyclic ring containing dual aromatase-sulfatase inhibitors (DASIs) based on the aromatase inhibitor (AI) 4-[(4-bromobenzyl)(4H-1,2,4-triazol-4-yl)amino] benzonitrile are reported. Biological evaluation with JEG-3 cells revealed structure-activity relationships. The X-ray crystal structure of sulfamate 23 was determined, and selected compounds were docked into the aromatase and steroid sulfatase (STS) crystal structures. In the sulfamate-containing series, compounds containing a naphthalene ring are both the most potent AI (39, IC_50AROM=0.25 nm) and the best STS inhibitor (31, IC_50STS=26 nm). The most promising DASI is 39 (IC_50AROM= 0.25 nm, IC_50STS=205 nm), and this was evaluated orally in vivo at 10 mgkg^-1, showing potent inhibition of aromatase (93%) and STS (93%) after 3 h. Potent aromatase and STS inhibition can thus be achieved with a DASI containing a bicyclic ring system; development of such a DASI could provide an attractive new option for the treatment of hormone-dependent breast cancer.

Full text of DOI:10.1002/cmdc.201000203

DOI: 10.1002/cmdc.201000203
Bicyclic Derivatives of the Potent Dual Aromatase–Steroid
Sulfatase Inhibitor 2-Bromo-4-{[(4-cyanophenyl)(4H-1,2,4-
triazol-4-yl)amino]methyl}phenylsulfamate: Synthesis, SAR,
Crystal Structure, and in vitro and in vivo Activities
Paul M. Wood,[a] L. W. Lawrence Woo,[a] Jean-Robert Labrosse,[a] Mark P. Thomas,[a]
Mary F. Mahon,[b] Surinder K. Chander,[c] Atul Purohit,[c] Michael J. Reed†,[c] and
Barry V. L. Potter*[a]
The design and synthesis of a series of bicyclic ring containing
dual aromatase–sulfatase inhibitors (DASIs) based on the aro-
matase inhibitor (AI) 4-[(4-bromobenzyl)(4H-1,2,4-triazol-4-yl)a-
mino]benzonitrile are reported. Biological evaluation with JEG-
3 cells revealed structure–activity relationships. The X-ray crys-
tal structure of sulfamate 23 was determined, and selected
compounds were docked into the aromatase and steroid sulfa-
tase (STS) crystal structures. In the sulfamate-containing series,
compounds containing a naphthalene ring are both the most
potent AI (39, IC50AROM =0.25 nm) and the best STS inhibitor
(31, IC50STS =26 nm). The most promising DASI is 39 (IC50AROM
=
0.25 nm, IC50STS =205 nm), and this was evaluated orally in vivo
at 10 mgkgꢀ1, showing potent inhibition of aromatase (93%)
and STS (93%) after 3 h. Potent aromatase and STS inhibition
can thus be achieved with a DASI containing a bicyclic ring
system; development of such a DASI could provide an attrac-
tive new option for the treatment of hormone-dependent
breast cancer.
Introduction
The hormone-dependent nature of breast cancer was first de-
scribed in 1896.[1] Various agents have been developed since
then to either modulate tumour cell oestrogen receptor (ER)
function or to decrease the levels of circulating oestrogens.
The widespread application of endocrine therapy with these
agents has led to a significant decrease in breast cancer mor-
tality. Among these are the selective ER modulators (SERMs)
such as tamoxifen, raloxifene, and toremifene; the pure anti-
oestrogens such as fulvestrant; luteinising-hormone-releasing
hormone agonists such as leuprolide and goserelin; and the
third-generation selective aromatase inhibitors (AIs) anastro-
zole, letrozole, and exemestane (Figure 1).[2–4]
therapy had failed. However, the results from several large
randomised neo-adjuvant and adjuvant clinical trials have re-
vealed that the third-generation AIs consistently show im-
proved efficacy over tamoxifen.[5–7] The data from the adjuvant
AI trials suggests that substituting an AI for tamoxifen, se-
quencing to an AI after 2–3 years on tamoxifen, and following
five years of tamoxifen treatment with extended adjuvant ther-
apy with an AI all significantly decrease the risk of recurrence
in postmenopausal women with hormone-dependent breast
cancer (HDBC). The results from these clinical trials point to a
more extensive use of AIs in the treatment of HDBC.
The emergence of steroid sulfatase (STS) inhibitors has pro-
vided a promising new therapy for the treatment of HDBC.
After the discovery of the pharmacophore for potent irreversi-
ble STS inhibition (i.e., a phenol sulfamate ester), a large
number of steroidal and nonsteroidal inhibitors were synthes-
ised and evaluated.[8–10] The most developed of these is the
These AIs were initially used for the treatment of advanced
breast cancer in postmenopausal women for whom tamoxifen
[a] Dr. P. M. Wood, Dr. L. W. L. Woo, Dr. J.-R. Labrosse, Dr. M. P. Thomas,
Prof. B. V. L. Potter
Department of Pharmacy and Pharmacology and Sterix Ltd.
University of Bath, Claverton Down, Bath BA2 7AY (UK)
Fax: (+44)1225-386-114
E-mail: b.v.l.potter@bath.ac.uk
[b] Dr. M. F. Mahon
X-Ray Crystallographic Suite, Department of Chemistry
University of Bath, Claverton Down, Bath, BA2 7AY (UK)
[c] Dr. S. K. Chander, Dr. A. Purohit, Prof. M. J. Reed
Endocrinology and Metabolic Medicine and Sterix Ltd., Imperial College
London, Faculty of Medicine, St. Mary’s Hospital, London, W2 1NY (UK)
Figure 1. Third-generation aromatase inhibitors anastrozole, letrozole, and
exemestane; steroid sulfatase inhibitors STX64 (BN83495) and EMATE.
[†] Prof. Michael John Reed, BSc, MSc, PhD, DSc, FRCPath (1944–2009).
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B. V. L. Potter et al.
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nonsteroidal compound STX64 (BN83495, Figure 1),[11–13] which
has been evaluated in a phase I clinical trial for the treatment
of patients with advanced breast cancer.[14] The clinical data
from this trial showed that a treatment protocol consisting of
STX64 at doses of either 5 or 20 mg resulted in potent inhibi-
tion of STS activity in peripheral blood lymphocytes and biop-
sied breast tumour tissue without showing any serious drug-
related adverse events. More significantly, stable disease was
observed in five out of eight evaluable patients. STX64 is now
in phase II trials for several endocrine-driven cancers including
endometrial and prostate.
the A/B ring system found in the potent steroidal STS inhibitor
EMATE (Figure 1). The ring systems investigated included tetra-
hydronaphthalene, naphthalene, indole, benzoxazole, and ben-
zofuran motifs. A number of these motifs have been used pre-
viously in the design of STS inhibitors, such as 5,6,7,8-tetrahy-
dronaphthalene-2-O-sulfamate,[9] the sulfamoyloxy-substituted
2-phenylindole series of compounds[25,26] and 6-[2-(adamantyli-
dene)hydroxybenzoxazole]-O-sulfamate.[27,28] All the novel
YM511-derived sulfamates were tested for both aromatase and
sulfatase inhibition in JEG-3 cells, whereas only aromatase in-
hibition was determined for their phenolic precursors. Docking
of selected compounds into the crystal structures of human ar-
omatase[29] and STS[30] was carried out in order to understand
how these inhibitors may interact with the active sites of these
enzymes. One promising compound was investigated for dual
inhibition in vivo.
The targeting of multiple biological targets with a single
chemical agent is an emerging strategy in drug design.[15–17]
A
conceivable application of this strategy for the treatment of
HDBC would be the combination of the pharmacophores for
aromatase and STS inhibition to give a dual aromatase–sulfa-
tase inhibitor (DASI). We previously reported the synthesis and
biological activity of several series of nonsteroidal DASIs that
are structurally based on the known AIs YM511 (1, Figure 2)
e.g., 2–5 (Figure 2), letrozole, e.g., 6 (Figure 2), and anastro-
zole.[18–23] Dual inhibition was achieved by incorporating the
Chemistry
The preparation of 4-[(4-cyanophenyl)amino]-4H-1,2,4-triazole
(8, Scheme 1) and the reference AI 1 was carried out according
to the method reported by Okada et al.;[31] the reference STS
inhibitor STX64 was synthesised according to the protocol of
Woo et al.[11]
Figure 2. YM511 (1), YM511-derived DASIs 2–5, a letrozole-derived DASI 6,
and biphenyl-containing DASI 7.
Scheme 1. Reagents and conditions: a) 4-amino-4H-1,2,4-triazole, KOtBu,
DMSO, 08C!RT; b) NaH, BnBr, DMF, 08C!RT; c) ethyl formate, KOtBu,
ꢀ788C!RT; d) BH3·tBuNH2, BF3·Et2O, CH2Cl2, ꢀ788C!RT; e) p-toluenesulfon-
yl chloride, pyridine, CHCl3, 08C!RT; f) 8, NaH, DMF, RT; g) H2, Pd/C (10%),
THF/MeOH, RT; h) H2NSO2Cl, DMA, 08C!RT.
pharmacophore for STS inhibition into the AI whilst preserving
the principle features necessary for aromatase inhibition. A
heteroaryl ring (such as triazole) in conjunction with other
enzyme active site binding components constitutes the phar-
macophore for aromatase inhibition in nonsteroidal AIs. In the
YM511-based DASI series, the best compounds in vitro were 4
(IC50AROM =0.82 nm, IC50STS =39 nm) and 5 (IC50AROM =0.77 nm,
IC50STS =590 nm) (Figure 2).[20] In vivo, in PMSG-treated imma-
ture female rats, both compounds exhibited potent dual inhib-
ition 3 h after a single oral dose of 10 mgkgꢀ1.[20] We also re-
ported[24] on a series of DASIs obtained following the introduc-
tion of the pharmacophore for aromatase inhibition into a bi-
phenyl template primarily designed for STS inhibition. From
this series, the best compound in vitro was 7 (IC50AROM =0.5 nm,
IC50STS =5.5 nm).
All of the novel sulfamates and phenols described herein
were prepared according to the schemes described below. The
final compounds and intermediates were characterised by
standard analytical methods, and the purity of the compounds
tested in vitro was evaluated by HPLC.
The synthesis of tetrahydronaphthalene derivative 16 from
6-hydroxy-3,4-dihydro-2H-naphthalen-1-one (prepared as re-
ported by Woo et al.[9]) is outlined in Scheme 1. Benzyl protec-
tion of phenol 9 was followed by deprotonation of 10 with po-
tassium tert-butoxide and reaction with ethyl formate to give
11. The reduction of 11 with borane gave alcohol 12 which
was converted into p-toluenesulfonate ester 13. Reaction of
the sodium hydride generated anion of 8 with 13, and subse-
Our objective was to further investigate the structure–activi-
ty relationship for YM511-derived DASIs by incorporating a
range of bicyclic ring systems which may serve as a mimic of
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Bicyclic DASI Derivatives
quent debenzylation by catalytic
hydrogenation, furnished phenol
15. Finally, the phenol was sulfa-
moylated according to Okada
et al.[32] with excess sulfamoyl
chloride in N,N-dimethylaceta-
mide to give 16 as a racemate.
The naphthalene-containing
derivative 23 was prepared in
five steps from 6-hydroxy-2-
naphthoic acid (17) as shown in
Scheme 2. Following benzyl pro-
tection of phenol 17, the result-
ing ester was reduced with
LiAlH4 to furnish alcohol 19.
Functional group interconver-
sion with thionyl chloride gave
chloride 20, which was then
used to alkylate the anion of
compound 8. The benzyl group
was removed from 21 by catalyt-
ic hydrogenation to give phenol
22, which was sulfamoylated
under the conditions previously
described to furnish DASI 23. An
X-ray crystal structure of 23 was
obtained from a crystal (approxi-
Figure 3. Top: X-ray crystal structure of 23 (CCDC deposition code: 771910); ellipsoids are represented at 30%
probability. Bottom: portion of extended structure present in 23 illustrating the network of intermolecular hydro-
gen bonding.
mate dimensions: 0.30ꢁ0.25ꢁ0.25 mm) grown by
slow evaporation of a solution of 23 in acetone
(Figure 3). The packing of 23 within the crystal is also
displayed, and the hydrogen bonds between the
amino groups of the sulfamates and the triazole
rings are indicated. The lattice is dominated by hy-
drogen bonded tapes, with each sulfamate group hy-
drogen bonding to two different triazole rings.
Scheme 2. Reagents and conditions: a) NaH, BnBr, DMF, 08C!RT; b) LiAlH4, THF, RT;
c) SOCl2, CH2Cl2, 08C!RT; d) 8, NaH, DMF, RT; e) H2, Pd/C (10%), THF/MeOH, RT;
f) H2NSO2Cl, DMA, 08C!RT.
Initially, chloro derivative 31 was prepared analo-
gously to 23. However, problems were encountered
with the debenzylation of the phenol by catalytic hy-
drogenation, as this resulted in the formation of a
small amount of dechlorinated material. This by-
product was difficult to remove during purification,
making an alternative synthesis desirable.
A change in the phenolic hydroxy protecting
group from benzyl, as used in the synthesis of 23, to
a triisopropylsilyl (TIPS) group resulted in an im-
proved route for the synthesis of 31 and provided a
synthetic route to 39 (Scheme 3). For the synthesis of
31, esterification of 6-hydroxy-2-naphthoic acid was
followed by chlorination with sulfuryl chloride and
then by TIPS protection of the phenol to furnish 26.
Reduction of the ester with lithium borohydride/
boron trimethoxide was followed by formation of
chloride 28 using thionyl chloride, which was subse-
quently used to alkylate the anion of 8. This reaction
gave a mixture of TIPS-protected and -deprotected
material; full deprotection could be achieved follow-
Scheme 3. Reagents and conditions: a) Br2, THF, RT; b) MeOH, HCl (cat.), reflux; c) SO2Cl2,
AcOH, RT; d) TIPSCl, imidazole, DMF, RT; e) LiBH4, B(OMe)3, Et2O, RT; f) SOCl2, CH2Cl2, RT;
ing treatment with tetra-n-butylammonium fluoride g) 8, NaH, DMF, RT; h) TBAF, THF, RT; i) H2NSO2Cl, DMA, 08C!RT.
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(TBAF, 1m) in tetrahydrofuran.
The final sulfamoylation was
achieved under the conditions
previously described to give 31.
The bromination of 6-hydroxy-2-
naphthoic acid (17) with bro-
mine was carried out according
to Huh and Jin[33] to give 32.
This was followed by the se-
quence described above to pro-
vide a route for the synthesis of
39 from 32.
The synthesis of the indole-
containing sulfamates 45 and
52 and phenol 55 from com-
mercially available 5-benzylox-
yindole (40) is shown in
Scheme 4. The first step in the
synthesis of 45 is reaction of the
Scheme 4. Reagents and conditions: a) NaH, ethylene carbonate, RT; b) p-toluenesulfonyl chloride, pyridine, CHCl3,
08C!RT; c) 8, K2CO3, DMF, RT; d) H2, Pd/C (10%), THF/MeOH, RT; e) H2NSO2Cl, DMA, 08C!RT; f) oxalyl chloride,
sodium
hydride
generated
Et2O, 08C; g) LiAlH4, THF, reflux; h) PBr3, Et2O, ꢀ58C; i) CH3I, K2CO3, DMF, RT; j) 8, NaH, DMF, RT; k) formaldehyde(aq)
dimethylamine(aq), AcOH, dioxane, 08C!RT; l) 8, H2O/EtOH, reflux.
,
anion of 5-benzyloxyindole with
ethylene carbonate to give alco-
hol 41. The reaction of 41 with
carbon tetrabromide/triphenyl-
phosphine to give the corre-
sponding bromide was low
yielding, so 41 was converted
into p-toluenesulfonate ester 42
and reacted with 8 in the pres-
ence of potassium carbonate.
Debenzylation by catalytic hy-
drogenation gave phenol 44,
which was then sulfamoylated
to give 45. For the preparation
of 52, the synthesis begins with
the reaction between 40 and
oxalyl chloride[34] to give 46,
Scheme 5. Reagents and conditions: a) 0.1m NaOH(aq), reflux; b) NaH, BnBr, DMF, 08C!RT; c) LiAlH4, THF, RT; d) p-
toluenesulfonyl chloride, pyridine, CHCl3, 08C!RT; e) 8, NaH, DMF, RT; f) H2, Pd/C (10%), THF/MeOH, RT;
g) H2NSO2Cl, DMA, 08C!RT.
which was subsequently reduced with lithium aluminium hy-
dride to give 47. The conversion of the alcohol to the bromide
with phosphorus tribromide[35] was followed by alkylation of
48 with methyl iodide/potassium carbonate to give 49. The
anion of 8 was reacted with 49 to give 50, and upon sequen-
tial deprotection and sulfamoylation furnished the desired sul-
famate 52. The first step in the preparation of 55 was the reac-
tion of 40 with formaldehyde and dimethylamine to give 53,
following the method of Ek and Witkop.[36] This tertiary amine
was then reacted with 8 in a manner similar to that reported
for the reaction of gramine with secondary amines[37]
via an amine exchange reaction and liberation of di-
methylamine to give 54. Subsequent debenzylation
furnished phenol 55, but for an unknown reason the
sulfamate of 55 could not be prepared under the
usual sulfamoylation conditions with sulfamoyl chlo-
ride/N,N-dimethylacetamide or even with our older
conditions of sodium hydride, sulfamoyl chloride/
Benzofuran-containing compound 63 was prepared from (6-
hydroxybenzofuran-3-yl)acetic acid[38,39] (57) according to the
route illustrated in Scheme 5. Benzyl protection of 57 was fol-
lowed by reduction with lithium aluminium hydride to give al-
cohol 59, which was converted into p-toluenesulfonate ester
60. Reaction of the anion of 8 with 60 was followed by depro-
tection and sulfamoylation as previously described to produce
63.
Compound 68 was synthesised from 2-methylbenzoxazol-6-
ol[27] (64) as shown in Scheme 6. Benzyl protection was fol-
Scheme 6. Reagents and conditions: a) NaH, BnBr, DMF, 08C!RT; b) N-bromosuccini-
N,N-dimethylformamide.[9]
mide, benzoyl peroxide, CCl4, reflux; c) 8, NaH, DMF, RT; d) H2, Pd/C (10%), THF/MeOH,
RT.
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Bicyclic DASI Derivatives
lowed by radical bromination to give 66, which was reacted
with the anion of 8. Debenzylation by catalytic hydrogenation
gave 68. However, despite several attempts, no sulfamoylation
of the phenol to give the desired sulfamate was observed, as
the standard sulfamoylation conditions resulted in the forma-
tion of decomposition products.
Table 1. In vitro inhibition of aromatase and STS activity in JEG-3 cells by
1, STX64, 2–4, 69, and the bicyclic sulfamates described herein.
Biological Results and Discussion
IC50 [nm]
A) Sulfamoylated compounds
Compd
X=OSO2NH2
Aromatase
STS
1, YM511[a]
0.5ꢁ0.03
–
The in vitro inhibition of aromatase and STS activity by each
sulfamate was measured in a preparation of an intact monolay-
er of JEG-3 cells. The results are reported either as IC50 values
or as a percentage of aromatase/STS inhibition at 10 mm, and
are compared with the reference AI 1[18] and the reference STS
inhibitor STX64[18] (Table 1). The biological activities of 2, 3,
4,[18] and 69[23] have been reported previously.
STX64[a]
–
1.5ꢁ0.3
2[a]
100ꢁ7.8
2.3ꢁ0.3
0.82ꢁ0.3
0.89ꢁ0.3
5.2ꢁ2.1
31ꢁ2
227ꢁ29
20ꢁ2.1
39ꢁ4.2
>10000
42.6%[c]
367ꢁ19
3[a]
All of the new sulfamates described in Table 1 exhibited
good to potent aromatase inhibition in vitro, demonstrating
the feasibility of incorporating a bicyclic ring system into a
YM511-derived DASI whilst retaining high inhibitory activity.
Replacement of the phenyl ring found in 2 with a tetrahy-
dronaphthalene ring system gives 16. The STS inhibitory activi-
ty of a related compound, 5,6,7,8-tetrahydronaphthalen-2-yl
sulfamate, compared with that of EMATE in intact MCF-7
breast cancer cells has been previously reported.[8] Although
5,6,7,8-tetrahydronaphthalen-2-yl sulfamate was found to be
less potent than EMATE (47% at 1 mm and 97% at 10 mm
versus >99% inhibition at 0.1 mm for EMATE), significant STS
inhibition was observed. Compound 16 was tested as a race-
mic mixture and found to be a relatively potent inhibitor of ar-
omatase (IC50 =5.2 nm compared to 0.5 nm for YM511) but a
weak inhibitor of STS (42.6% inhibition at 10 mm compared to
1.5 nm for STX64 in the same assay). The biological activity of
16 relative to that of 2 and 69 provides insight into the role of
the linker between the STS and the aromatase inhibitory phar-
macophores in dual inhibition. For aromatase inhibition,
4[a]
69[b]
(ꢁ)-16
23
31
39
2.1ꢁ1.0
26ꢁ1.0
205ꢁ40
0.25ꢁ0.05
45
52
63
2.7ꢁ1.6
2.3ꢁ0.2
4.0ꢁ0.42
<10%[c]
lengthening the linker results in a beneficial effect (IC50AROM
=
100 nm for 2 versus 5.2 nm for 16 and 0.89 nm for 69). Howev-
er, elongation of the linker has a negative effect on the ability
of these compounds to inhibit STS activity in JEG-3 cells
(IC50STS =227 nm for 2 versus 42.6% at 10 mm for 16 and
>10000 nm for 69).
4%[c]
The naphthalene ring present in compounds 23, 31, and 39
is similar to the A/B ring system found in equilenin, an oestro-
genic steroid found in horses. One advantage of this series of
compounds over the tetrahydronaphthalene ring system is
that elimination of the chiral centre makes these derivatives
more attractive for further development. The result of switch-
ing from 16 to the naphthalene ring in 23 is a much improved
inhibitor of STS with an IC50 value of 367 nm, but a weaker aro-
matase inhibitor with an IC50 value of 31 nm. Compared with
the previously reported biological activity of 2 under the same
assay conditions, 23 is a threefold better aromatase inhibitor
(IC50AROM =31 nm versus 100 nm) and an equipotent STS inhibi-
tor (IC50STS =367 nm versus 227 nm). The two halogenated
44.9%[c]
[a] Data taken from [18]. [b] Data taken from [23]. [c] Percent inhibition at
10 mm.
naphthalene derivatives 31 and 39 are both more potent dual
inhibitors than their non-halogenated counterpart 23. This is in
agreement with previous investigations into the design of
YM511-based DASIs which revealed that the presence of a hal-
ogen ortho to the sulfamate group results in an increase in
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both aromatase and STS inhibitory activity.[18,20,23] The increase
in aromatase inhibition is reasoned to be due to an increase in
the lipophilicity of the compound which may result in tighter
binding of the halogenated derivative to the active site. The in-
crease in STS inhibition can be attributed to a lowering of the
pKa value of the phenol, enhancing its leaving group ability
and hence the potential of the corresponding sulfamate to in-
activate STS through sulfamoylation. Of the trio of compounds
comprising 23, 31, and 39, the most potent STS inhibitor is
the chlorinated derivative 31 (IC50STS =26 nm), whilst the bromi-
nated compound 39 is the most potent AI (IC50AROM =0.25 nm),
even more potent than 1 in the same assay (IC50AROM =0.5 nm).
For aromatase inhibition, this finding replicates that previously
observed in the first series of YM511-based DASIs, in which the
brominated derivative 4 (IC50AROM =0.82 nm) is more potent
than its chlorinated counterpart 3 (IC50AROM =2.3 nm).[20] Howev-
er, for STS inhibition, there is an eightfold difference in potency
between 31 and 39. This finding differs from that previously
reported for monocyclic compounds 4 (IC50STS =39 nm) and 3
(IC50STS =20 nm), which are similar in potency.
indole-containing compounds 45 and 52 (IC50AROM =4.0 nm
versus 2.7 and 2.3 nm), but proved to be a better STS inhibitor
(44.9% at 10 mm versus 4 and <10%). Taken together, these
results suggest that it may be possible to optimise the indole
and benzofuran derivatives to achieve potent aromatase inhib-
ition, but it may be difficult to achieve concomitant potent STS
inhibition.
Schreiner et al.[27] have reported the potent irreversible in-
hibition of STS by 6-(2-adamantan-2-ylidene-hydroxybenzoxa-
zole)-O-sulfamate. In cellular assays with human keratinocytes,
sebocytes, and fibroblasts, this benzoxazole-containing com-
pound blocked STS activity with IC50 values in the range of
0.15–0.8 nm and in MCF-7 breast cancer cells with an IC50 value
of 2.3 nm. Despite this published precedent for the preparation
of a benzoxazole derivative containing a sulfamate group at
the 6-position, attempts to sulfamoylate 68 proved unsuccess-
ful (see Chemistry section above). However, the aromatase in-
hibition exhibited by 68 (IC50AROM =16 nm) suggests that it is
unlikely that the corresponding sulfamate would be as potent
an AI as 39.
The other ring systems used in the design of the series of
DASIs discussed herein have been previously incorporated in
either AIs (benzofuran), STS inhibitors (benzoxazoles), or both
(indoles). For the latter series, this is exemplified by a range of
novel aromatase inhibitors based on 2-, 3-, 4-, 5-, 6-, or 7-
[(aryl)(azolyl)methyl]-1H-indole systems,[40–43] from which the
most potent compound is 4-[(1H-imidazol-1-yl)(1H-indol-4-yl)-
methyl]benzonitrile, with an IC50 value of 11.5 nm when evalu-
ated in a microsomal preparation of human placental tissue.[43]
The potency of the two indole-containing derivatives de-
scribed herein (45 and 52) against aromatase is similar, with
IC50 values in the low nanomolar range (IC50AROM =2.7 and
2.3 nm, respectively). These results suggest that the sulfamoy-
lated indole derivatives are potent AIs, and the incorporation
of an ethylene linker at either the 1- or 3-positions of the
indole ring has little effect on aromatase inhibition. However,
both 45 and 52 exhibit weak STS inhibition. This finding sug-
gests that having a sulfamate group at the 5-position of the
indole ring is not conducive to STS inhibition. A similar obser-
vation was made for a series of sulfamoyloxy-substituted 2-
phenylindoles reported by von Angerer and co-workers.[25]
Despite being originally synthesised as antifungal agents,
Finally, all the bicyclic-heterocycle-containing DASIs are
weaker STS inhibitors than the naphthalene-containing DASIs.
This could be caused by a number of factors, including the
electronic effects of the ring system resulting in a lowering of
the leaving group ability of the sulfamate and poor presenta-
tion of the sulfamate group to the catalytic site by the bicyclic-
heterocycle-containing DASIs.
B) Phenolic compounds
The irreversible inactivation of STS by a sulfamate-based DASI
should initially result in the formation of the corresponding
phenol until, in principle, all the STS activity has been eliminat-
ed.[48] Hydrolysis of the sulfamate following prolonged circula-
tion in plasma will also give rise to this phenol. These phenols
still contain the pharmacophore for aromatase inhibition and
have the potential to act as AIs in their own right. The aroma-
tase inhibition data for the phenols described herein are listed
in Table 2 along with data previously reported for 1 and 70.[20]
The most potent phenol in the series against aromatase is
the brominated naphthalene derivative 38 (IC50 =0.1 nm),
making this compound fivefold more potent than 1 (IC50 =
0.50 nm) in this assay. With the exception of 30 and 44, there
is a trend for the phenols to show a small but significant in-
crease in aromatase inhibition relative to the corresponding
sulfamates. This finding is in agreement with our previous ex-
perience with YM511-derived DASIs[18,20] and could be due to
the sulfamate moiety being too bulky or polar relative to the
hydroxy group for optimum binding of these inhibitors to the
aromatase active site. For example, the calculated tPSA and
ClogP values for the phenolic 38 are 75.22 ꢂ2 and 3.1418, re-
spectively (ChemDraw Ultra v. 11.0.1), whilst for the sulfamate-
containing 39 the tPSA is 124.38 ꢂ2 and the ClogP is 2.216.
The racemic tetrahydronaphthalene-containing phenol 15 is
a surprisingly much more potent AI than the corresponding
naphthalene derivative 22. Its potency is on the same order of
magnitude as brominated derivative 38. Replacement of the
substituted
1-[(benzofuran-2-yl)(phenylmethyl)]imidazoles,
along with their triazole and pyridine counterparts, have
emerged as a class of potent AIs. Amongst the compounds in
this series, 1-[benzofuran-2-yl(4-chlorophenyl)methyl]-1H-imida-
zole has been shown to display potent activity in vitro and
in vivo with enantioselectivity in favour of the (+)-enantiomer
(IC50AROM =5.3 nm versus 65.0 nm). The asymmetric synthesis of
this compound[44] and the corresponding triazole derivative[45]
from a homochiral a-arylpropargylamine has been reported.[46]
The 6-methoxy- and 6-hydroxy-substituted benzofuran deriva-
tives of 1-[(benzofuran-2-yl)(phenylmethyl)]pyridines, imida-
zoles, and triazoles were reported[47] to be AIs with IC50 values
in the range of 0.01–1.46 mm, and are more potent than the
unsubstituted parent compounds. The benzofuran-containing
compound 63 was similar in aromatase inhibition to the
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Bicyclic DASI Derivatives
than 55. This reasoning is consistent with that reported[49] for
the 3-(1-azolylmethyl)-1H-indole series in which alkylation of
the indolic nitrogen atom resulted in an increase in aromatase
inhibition. These results suggest that a hydrogen bond donor
at this position of the indole ring is detrimental to activity. The
benzofuran-containing phenol 62 (IC50 =1.50 nm) is a relatively
potent inhibitor of aromatase with an IC50 value similar to that
of 44 and 51 in the indole series, whereas the benzoxazole-
containing compound 68 is a weaker AI, with an IC50 value of
16 nm, which is an order of magnitude higher than that of 62.
Table 2. In vitro inhibition of aromatase activity in JEG-3 cells by 1 and
the phenols described herein.
Compd
IC50 [nm]
1, YM511[a]
0.5ꢁ0.03
70[b]
(ꢁ)-15
22
23ꢁ1
0.25ꢁ0.04
14ꢁ0.8
C) Inhibition of aromatase and sulfatase in vivo
To investigate the inhibition of aromatase and sulfatase in vivo,
compound 39 was studied in immature female Wistar rats at a
single oral dose of 10 mgkgꢀ1. The results are shown in
Figure 4 along with those previously reported for compounds
1, 2, and 4.[18] For aromatase, compound 39 decreases PMSG-
induced plasma oestradiol levels by 93% 3 h after administra-
tion which is a notable improvement over the AI 1 (70% inhib-
ition) and previously reported DASIs 2 and 4, with 38 and 68%
inhibition, respectively. Comparison of the STS inhibition by 2
and 4 (ꢂ98% for both compounds) with that for 39 (93% in-
hibition) reveals that the three compounds are similar in po-
tency. These results confirm that the high dual-inhibitory activi-
ties exhibited by 39 in vitro are retained in vivo.
30
38
3.8ꢁ0.9
0.1ꢁ0.06
44
51
3.2ꢁ0.9
1.5ꢁ0.1
16.0ꢁ2.6
55
62
Figure 4. Inhibition of aromatase and STS activities after 3 h in female Wistar
rats. Compounds indicated were administered at 10 mgkgꢀ1 p.o.
D) Molecular modelling
1.5ꢁ0.21
16ꢁ1.4
The human aromatase crystal structure (PDB ID: 3EQM)[29] has
androstenedione co-crystallised in the substrate binding site.
To assess the suitability of this structure for use in docking
studies, androstenedione was removed from the crystal struc-
ture and, using the docking program GOLD,[50] the steroid was
docked back in. The best pose of the docked androstenedione
overlays the crystal structure very well, with the 17 carbon
atoms of the steroid core having an RMSD of 0.64 ꢂ with dis-
tances between equivalent atoms varying from 0.40 to 0.91 ꢂ.
In the crystal structure the C19 atom is 4.01 ꢂ from the haem
iron, and in the docked structure the distance is 3.74 ꢂ.
68
[a] Data taken from [18]. [b] Data taken from [20].
aryl ring in previously reported compound 70 with a naphtha-
lene ring to give 22 results in an equipotent AI. In common
with the trend observed for their corresponding sulfamate, the
aromatase inhibition exhibited by the naphthalene-containing
phenols increases in the order 22, 30, and 38 as a result of hal-
ogenation. In the indole series, both 44 and 51 are potent AIs
with a similar level of activity. In contrast, 55 is some 11-fold
weaker as an AI than 51. This disparity in potency is most
likely caused by the unsubstituted indolic nitrogen atom in 55,
although notably, 51 has one more linking methylene group
Following the successful docking of androstenedione into
the aromatase active site, the docking of the three naphtha-
lene-containing sulfamates 23, 31 and 39, and reference AI 1
was undertaken. As all three sulfamates docked in a similar ori-
entation, only the pose obtained for 39 along with that for 1
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B. V. L. Potter et al.
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Figure 5. The docking of 39 (cyan), 1 (yellow), and androstenedione (buff)
into the human aromatase crystal structure[29] using the GOLD docking pro-
gram version 3.1.1.30. The haem iron atom is represented by an orange ball,
and the dotted lines represent potential hydrogen bonding interactions.
and androstenedione is shown in Figure 5. The docking of 39
resembles that of 1 with the sulfamoylated naphthalene ring
occupying the same area as the brominated ring in 1 and with
the benzonitrile group positioned in the same area of the
active site as that in 1. Hydrogen bond interactions with this
benzonitrile group are known to be important for potent in-
hibitory activity in nonsteroidal aromatase inhibitors. For (ꢀ)-
fadrozole hydrochloride, it has been suggested that the benzo-
nitrile group present in this compound mimics the C17 carbon-
yl group found in the natural substrate androstenedione.[51]
Comparison of the position of the benzonitrile groups in 39
and 1 indicates that they are in close proximity to the 17-keto
oxygen atom in androstenedione, suggesting that hydrogen
bonding between the backbone amide of Met374 and the
benzonitrile group may be possible (distance between the two
is 2.49 ꢂ). This would mimic one of the two interactions ob-
served for the 17-keto oxygen atom in androstenedione in the
crystal structure,[29] the other being a weak contact with NH1
of Arg115. Interaction between the benzonitrile groups in 39
and 1 and Arg115 appears to be unlikely, with a distance of
6.76 ꢂ between them. As shown in Figure 5, the sulfamate
group of 39 can form hydrogen bond interactions with Glu483
(4.94 ꢂ to sulfamate NH2 group) and Arg192 (4.85 ꢂ to an O
atom in the sulfamate group).
Figure 6. The docking of 39 (cyan) and STX64 (brown) into the crystal struc-
ture of STS. The Ca2+ ion is depicted as an orange ball, and the dotted lines
represent potential hydrogen bonding interactions.
Conclusions
A range of DASIs based on the AI YM511 was prepared and
tested for the inhibition of both aromatase and STS in JEG-3
cells. These novel DASIs contain a number of bicyclic ring sys-
tems such as tetrahydronaphthalene, naphthalene, benzofuran,
indole, and benzoxazole motifs, some of which have been pre-
viously used in the design of potent AIs and STS inhibitors.
The bicyclic sulfamate motif present in these DASIs is reasoned
to mimic the A/B ring systems found in the potent steroidal
STS inhibitors such as EMATE.
The results show that the best AI from this series of DASIs is
39 (IC50AROM =0.25 nm), whilst the best STS inhibitor is 31
(IC50STS =26 nm). Notably, both 31 and 39 contain a naphtha-
lene ring system. The most promising DASI is 39 (IC50AROM
=
0.25 nm, IC50STS =205 nm). For the parent phenols, the most
potent AI was 38 (IC50 =0.1 nm). Molecular modelling studies
indicate that 39 docks into the aromatase crystal structure[29]
with its benzonitrile group occupying a similar area of space as
the 17-keto oxygen atom of androstenedione. The high poten-
cy against aromatase observed for 39 could be due, in part, to
the mimicking of interactions from the 17-keto oxygen atom
of androstenedione by the benzonitrile group of 39. For STS,
39 docks in a similar orientation to that of STX64.
Compound 39 was evaluated in female Wistar rats at a
single oral dose of 10 mgkgꢀ1, and after 3 h excellent inhibi-
tion of aromatase (93%) and sulfatase (93%) was observed.
These results demonstrate that potent aromatase and STS in-
hibition can be achieved with a DASI containing a bicyclic ring
system; further SAR studies are ongoing. The development of
a DASI would provide an attractive new option for the treat-
ment of HDBC.
The docking of 39 and STX64 into the crystal structure of
STS[30] is shown in Figure 6. Compound 39 docks in a mode
that places the sulfamate group satisfactorily for interaction
with the gem-diol form of formylglycine residue 75, an interac-
tion thought to be necessary for inactivation of the enzyme. In
addition, the sulfamate group is able to form favourable inter-
actions with Thr165 and His290 in the active site. In a manner
similar to STX64, the remainder of the skeleton of 39 occupies
predominantly the hydrophobic tunnel leading to the active
site. The cyano group of 39 points towards Arg98 with which
it may interact, and the triazole ring can form a hydrogen
bond (2.99 ꢂ) to one of the side chain nitrogen atoms of
His485.
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Bicyclic DASI Derivatives
force field with Gasteiger–Hꢃckel charges as implemented within
SYBYL 7.3.
Experimental Section
In vitro and in vivo aromatase and sulfatase assays
Biological activities were performed essentially as described previ-
ously.[20] The extent of in vitro inhibition of aromatase and sulfatase
activities was assessed using intact monolayers of JEG-3 human
choriocarcinoma cells, which were chosen because these cells con-
stitutively express both enzymes maximally. Aromatase activity was
measured using [1b-3H]androstenedione (30 Cimmolꢀ1, PerkinElmer
Life Sciences, Waltham, MA, USA) over a 1 h period. Sulfatase activi-
ty was measured using [6,7-3H]E1S (50 Cimmolꢀ1, PerkinElmer Life
Sciences) over a 1 h period.
Chemistry
All chemicals were purchased from Aldrich Chemical Co. (Gilling-
ham, UK), Alfa Aesar (Heysham, UK) or Acros (Loughborough, UK).
All organic solvents of A.R. grade were supplied by Fisher Scientific
(Loughborough, UK). Anhydrous N,N-dimethylformamide (DMF),
N,N-dimethylacetamide (DMA), and tetrahydrofuran (THF) were
purchased from Aldrich. Sulfamoyl chloride was prepared by an
adaptation of the method of Appel and Berger[53] and was stored
as a solution in toluene as described by Woo et al.[54]
In vivo aromatase and sulfatase activities were measured in imma-
ture female Wistar rats. All experiments were carried out under
strict conditions that complied with institutional (Imperial College,
London) and Home Office guidelines [Animals (Scientific Proce-
dures) Act 1986]. Animals received a single subcutaneous injection
of pregnant mare’s serum gonadotropin (PMSG, 200 IU, Sigma).
Three days later, drugs (10 mgkgꢀ1) were administered orally in
THF/propylene glycol (10:90) as a single dose (0.1 mL). Blood and
liver samples were obtained 3 h after drug administration. Plasma
concentrations of oestradiol were measured using a radioimmuno-
assay kit (Diagnostic Products Corporation, Los Angeles, CA, USA)
to monitor the extent of aromatase inhibition. Liver STS activity
was determined by incubating rat liver homogenate with [3H]E1S
[7ꢁ105 dpm, 60 Cimmolꢀ1, adjusted to 20 mm with non-radioactive
E1S (Sigma)] for 1 h. The product was extracted with toluene, and
the radioactivity was measured by liquid scintillation spectrometry.
Results are expressed as the percentage inhibition of PMSG-stimu-
lated oestradiol levels for aromatase activity, or the percent activity
in untreated animals for STS activity (mean ꢁSE, n=3–5).
Thin-layer chromatography (TLC) was performed on pre-coated
aluminium plates (Merck, silica gel 60 F254). Product spots were vi-
sualised either by UV irradiation at l 254 nm or by staining with
either an alkaline solution of KMnO4 or dodecamolybdophosphoric
acid (5% w/v) in EtOH, followed by heating. Flash column chroma-
tography was performed on silica gel (Davisil silica 60A) or by
using pre-packed columns (Isolute) and gradient elution (solvents
1
indicated in the text) on a Flashmaster II system (Biotage). H and
13C NMR spectra were recorded with either a Jeol Delta 270 MHz or
a Varian Mercury VX 400 MHz spectrometer. Chemical shifts (d) are
reported in parts per million (ppm) relative to (CH3)4Si as an inter-
nal standard. Coupling constants (J) are recorded to the nearest
0.1 Hz. Mass spectra were recorded at the Mass Spectrometry Ser-
vice Centre, University of Bath. Elemental analyses were performed
by the Microanalysis Service, University of Bath. Melting points
(mp) were determined using either a Stuart SMP3 or a Stanford Re-
search Systems Optimelt MPA100 instrument, and are uncorrected.
LC–MS was performed using a Waters 2790 instrument with a ZQ
MicroMass spectrometer and PDA detector. The ionisation tech-
nique used was either APCI or ES (as indicated in the text). A
Waters Symmetry C18 (packing: 3.5 mm), 4.6ꢁ100 mm column and
gradient elution 5:95 CH3CN/H2O (at 0.5 mLminꢀ1) to 95:5 CH3CN/
H2O (at 1 mLminꢀ1) over 10 min were used. HPLC was undertaken
using a Waters 717 instrument with autosampler and PDA detector.
The column used was a Waters Symmetry C18 (packing: 3.5 mm),
4.6ꢁ150 mm with an isocratic mobile phase consisting of MeOH/
Crystallographic data
CCDC 771910 (23) contains the supplementary crystallographic
data for this paper. These data can be obtained free of charge
from The Cambridge Crystallographic Data Centre via
www.ccdc.cam.ac.uk/data_request/cif.
H2O (as indicated) at a flow rate of 1.4 mLminꢀ1
.
Molecular modelling
General method A: hydrogenation. 10% Pd/C was added to a so-
lution of the substrate in THF/MeOH. The solution was stirred
under an atmosphere of H2 (provided by addition from a balloon)
overnight. Excess H2 was then removed, and the reaction mixture
was filtered through Celiteꢄ washing with THF and MeOH, followed
by solvent removal in vacuo.
Models of 28, 36, and 1 were built in the SYBYL v. 7.3[52] molecular
modelling program. To obtain low-energy conformations of these
models, energy minimisation was performed to convergence using
the MMFF94s force field with MMFF94 charges. The docking pro-
gram GOLD v. 3.1.1 was used to dock the models into the aroma-
tase crystal structure.[29] The aromatase active site was defined as a
sphere of 12 ꢂ radius around the haem group iron atom. A dis-
tance constraint (minimum=2.00 ꢂ, maximum=2.30 ꢂ) was ap-
plied between the ligating triazole nitrogen atom of the ligand to
the haem iron atom. The coordination number of the iron atom
was defined as 6. The ligands were then docked to the enzyme a
total of 25 times each using the GOLDScore fitness function.
General method B: sulfamoylation. A solution of H2NSO2Cl in tol-
uene (0.7m) was concentrated in vacuo at 308C to furnish a yellow
oil, which solidified upon cooling in an ice bath. DMA and the sub-
strate were subsequently added, and the mixture was allowed to
warm to room temperature and was stirred overnight. The reaction
mixture was poured onto H2O and extracted three times with
EtOAc. The organic layers were combined, washed four times with
H2O, and then with brine, dried (MgSO4), and the solvent was re-
moved in vacuo.
The crystal structure of human placental oestrone/DHEA sulfatase
(PDB ID: 1P49) was used for building the gem-diol form of STS.
This involved a point mutation of the ALS75 residue in the crystal
structure to the gem-diol form of the structure using editing tools
within SYBYL 7.3. The resulting structure was then minimised with
the backbone atoms fixed to allow the gem-diol and surrounding
side chain atoms to adopt low-energy conformations. Minimisa-
tions were undertaken using SYBYL 7.3 by applying the AMBER7 99
6-(Benzyloxy)-3,4-dihydronaphthalen-1(2H)-one (10). NaH (60%
in mineral oil, 1.09 g, 27.2 mmol) was added in three equal por-
tions to a cooled (08C) solution of 6-hydroxy-3,4-dihydro-2H-naph-
thalen-1-one[9] (4.00 g, 24.7 mmol) in DMF (60 mL). After 10 min,
benzyl bromide (4.63 g, 27.1 mmol) was added, and the reaction
mixture was stirred for 2 h. The reaction mixture was poured onto
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B. V. L. Potter et al.
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H2O (100 mL) and extracted with EtOAc (2ꢁ60 mL). The combined
organic layers were washed with H2O (4ꢁ50 mL) and brine
(60 mL), dried (MgSO4), and the solvent was removed in vacuo. The
crude product was purified by recrystallisation twice from toluene
to give the title compound as a cream crystalline solid (4.23 g,
68%); mp: 98.5–1008C [lit. 988C][55]).
(C), 130.0 (CH), 129.9 (2ꢁCH), 129.8 (C), 128.6 (2ꢁCH), 128.0 (2ꢁ
CH), 127.9 (CH), 127.5 (2ꢁCH), 127.2 (C), 114.5 (CH), 113.0 (CH),
74.5 (CH2), 70.0 (CH2), 34.2 (CH), 31.2 (CH2), 28.5 (CH2), 25.4 (CH2),
21.7 ppm (CH3); MS (FAB): m/z (%): 422.2 (70) [M+H]+, 251.2 (75),
91.1 (100); HRMS-FAB: m/z [M]+ calcd for C25H26O4S: 422.1552,
found: 422.1564.
6-(Benzyloxy)-2-(hydroxymethylene)-3,4-dihydronaphthalen-
1(2H)-one (11). KOtBu (2.24 g, 0.02 mol) was added in small por-
tions to a cooled (ꢀ788C) solution of 10 (2.52 g, 0.01 mol) and
ethyl formate (1.48 g, 0.02 mol) in toluene (40 mL). The reaction
mixture was allowed to warm to room temperature and stirred for
2 h. Aqueous HCl (1.5m, 50 mL) was cautiously added, and the
mixture was extracted with Et2O (2ꢁ30 mL). The combined organ-
ics were washed with brine (70 mL), dried (MgSO4), and the solvent
was removed in vacuo. The crude product was purified using
Flashmaster II (EtOAc/hexane) to give the title compound as a
(ꢁ)-4-({[6-(Benzyloxy)-1,2,3,4-tetrahydronaphthalen-2-yl]me-
thyl}(4H-1,2,4-triazol-4-yl)amino)benzonitrile (14). Compound 8
(0.61 g, 3.30 mmol) was added in small portions to a cooled (08C)
suspension of NaH (60% in mineral oil, 0.16 g, 3.98 mmol) in DMF
(15 mL). The resulting solution was allowed to warm to room tem-
perature, and after 30 min, 13 (0.70 g, 1.66 mmol) was added, and
the reaction mixture was stirred overnight. The reaction mixture
was poured onto H2O (40 mL) and extracted with EtOAc (2ꢁ
30 mL). The combined organic layers were washed with H2O (3ꢁ
40 mL) and brine (40 mL) then dried (MgSO4), and the solvent was
removed in vacuo. The crude product was purified using Flashmas-
ter II (EtOAc/hexane) to give the title compound as a white solid
1
pale-yellow solid (2.45 g, 88%); H NMR (400 MHz, CDCl3): d=8.00
(1H, d, J=8.6, ArH), 7.99 (1H, s, CHOH), 7.50–7.36 (5H, m, ArH),
6.97 (1H, dd, J=8.0, 2.2, ArH), 6.85 (1H, d, J=2.2, ArH), 5.16 (2H, s,
CH2), 2.90 (2H, t, J=6.8, CH2), 2.60 ppm (2H, t, J=5.9, CH2);
13C NMR (100 MHz, CDCl3): d=184.4 (C), 172.7 (CH), 162.6 (C), 144.5
(C), 136.2 (C), 128.8 (CH), 128.7 (2ꢁCH), 128.3 (CH), 127.5 (2ꢁCH),
125.2 (C), 114.0 (CH), 113.6 (CH), 108.2 (C), 70.1 (CH2), 29.3 (CH2),
23.3 ppm (CH2); MS (APCI): m/z (%): 281.2 (100) [M+H]+, 214.1 (20),
157.9 (35), 140.9 (20); HRMS-FAB: m/z [M+H]+ calcd for C18H17O3:
281.1178, found: 281.1176.
1
(0.19 g, 27%); mp: 207–2098C; H NMR (270 MHz, [D6]DMSO): d=
9.09 (2H, s, 2ꢁNCHN), 7.75 (2H, AA’BB’, ArH), 7.45–7.30 (5H, m,
ArH), 6.98 (1H, d, J=8.1, ArH), 6.78–6.74 (2H, m, ArH), 6.67 (2H,
AA’BB’, ArH), 5.05 (2H, s, CH2), 3.88 (2H, d, J=7.1, CH2), 2.85 (1H,
dd, J=16.0, 4.5, CHH), 2.80–2.64 (2H, m, CH2), 2.52–2.42 (1H, m,
CHH), 2.00–1.92 (1H, m, CHH), 1.78–1.60 (1H, m, CHH), 1.52–
1.38 ppm (1H, m, CHH); 13C NMR (100 MHz, [D6]DMSO): d=156.8
(C), 152.5 (C), 144.0 (2ꢁCH), 137.8 (C), 137.6 (C), 134.4 (2ꢁCH),
130.3 (CH), 128.9 (2ꢁCH), 128.2 (CH), 128.0 (2ꢁCH), 127.9 (C), 119.6
(C), 114.7 (CH), 113.6 (2ꢁCH), 113.2 (CH), 102.7 (C), 69.5 (CH2), 59.5
(CH2), 33.3 (CH), 32.2 (CH2), 28.9 (CH2), 26.5 ppm (CH2); MS (APCI):
m/z (%): 436.0 (50) [M+H]+, 367.0 (100); HRMS-FAB: m/z [M+H]+
calcd for C27H26N5O: 436.2137, found: 436.2132.
(ꢁ)-[6-(Benzyloxy)-1,2,3,4-tetrahydronaphthalen-2-yl]methanol
(12). BF3·Et2O (5.76 g, 40.6 mmol) was added dropwise to a cooled
(ꢀ788C) solution of 11 (2.27 g, 8.11 mmol) and BH3·tBuNH2 (3.53 g,
40.6 mmol) in CH2Cl2 (130 mL). The reaction mixture was stirred for
1 h, then allowed to warm to room temperature and stirred for a
further 2 h. Aqueous HCl (1.5m, 60 mL) was cautiously added, and
the resultant was extracted with CH2Cl2 (3ꢁ60 mL). The combined
organic layers were washed with H2O (100 mL), dried (MgSO4), and
the solvent was removed in vacuo. The crude product was purified
using Flashmaster II (EtOAc/hexane) to give the title compound as
a colourless oil, which solidified on standing (2.09 g, 96%); mp:
(ꢁ)-4-{[(6-Hydroxy-1,2,3,4-tetrahydronaphthalen-2-yl)me-
thyl](4H-1,2,4-triazol-4-yl)amino}benzonitrile (15). As per general
method A using 10% Pd/C (55 mg), 14 (0.40 g, 0.94 mmol), and
THF/MeOH (1:1, 60 mL). The crude product was purified using
Flashmaster II (EtOAc/hexane) and then by flash column chroma-
tography (CHCl3/acetone) to give the title compound as a white
1
1
207–2098C; H NMR (400 MHz, CDCl3): d=7.49–7.32 (5H, m, ArH),
solid (0.19 g, 72%); H NMR (270 MHz, [D6]DMSO): d=9.06 (2H, s,
7.04 (1H, d, J=8.4, ArH), 6.80 (1H, dd, J=8.6, 2.6, ArH), 6.76 (1H, d,
J=2.6, ArH), 5.07 (2H, s, CH2), 3.72–3.62 (2H, m, CH2), 2.92–2.78
(3H, m, CHH and CH2), 2.48 (1H, dd, J=16.0, 11.0, CHH), 2.08–1.94
(2H, m, CH and CHH), 1.52–1.40 ppm (1H, m, CHH); 13C NMR
(100 MHz, CDCl3): d=156.8 (C), 137.9 (C), 137.3 (C), 130.1 (C), 128.6
(2ꢁCH), 128.3 (C), 127.9 (CH), 127.5 (2ꢁCH), 114.5 (CH), 112.8 (CH),
70.0 (CH2), 67.8 (CH2), 37.3 (CH), 31.6 (CH2), 29.1 (CH2), 25.9 ppm
(CH2); MS (APCI): m/z (%): 269.2 (60) [M+H]+; HRMS-FAB: m/z [M]+
calcd for C18H20O2: 268.1463, found: 268.1450.
2ꢁNCHN), 9.01 (1H, s, OH), 7.72 (2H, AA’BB’, ArH), 6.83 (1H, d, J=
8.2, ArH), 6.64 (2H, AA’BB’, ArH), 6.47 (1H, d, J=8.2, ArH), 6.45 (1H,
s, ArH), 3.84 (2H, d, J=6.9, CH2N), 2.83–2.58 (3H, m, CHH and CH2),
2.48–2.32 (1H, m, CHH), 1.98–1.85 (1H, m, CHH), 1.78–1.60 (1H, m,
CHH), 1.50–1.32 ppm (1H, m, CHH); 13C NMR (100 MHz, [D6]DMSO):
d=155.6 (C), 152.5 (C), 144.0 (2ꢁCH), 137.3 (C), 134.4 (2ꢁCH),
130.2 (CH), 125.8 (C), 119.6 (C), 115.2 (CH), 113.6 (2ꢁCH), 113.6
(CH), 102.7 (C), 59.6 (CH2), 33.4 (CH), 32.3 (CH2), 28.7 (CH2),
26.6 ppm (CH2); MS (APCI): m/z (%): 346.2 (100) [M+H]+; HRMS-
FAB: m/z [M+H]+ calcd for C20H20N5O: 346.1668, found: 346.1674;
HPLC (CH3CN/H2O, 70:30) tR =1.79 min (purity: 97%).
(ꢁ)-[6-(Benzyloxy)-1,2,3,4-tetrahydronaphthalen-2-yl]methyl-4-
methyl benzenesulfonate (13). p-Toluenesulfonyl chloride (0.36 g,
1.88 mmol) was added to a cooled (08C) solution of 12 (0.34 g,
1.27 mmol) and pyridine (0.20 g, 2.53 mmol) in CHCl3 (3.5 mL). The
solution was stirred for 1 h and then allowed to warm to room
temperature and stirred overnight. The solvent was removed in va-
cuo, and the crude product was purified using Flashmaster II
(EtOAc/hexane) to give the title compound as a white powder
(ꢁ)-6-{[(4-Cyanophenyl)(4H-1,2,4-triazol-4-yl)amino]methyl}-
5,6,7,8-tetrahydronaphthalen-2-yl sulfamate (16). As per general
method B using H2NSO2Cl (0.7m, 3.5 mL), DMA (3.5 mL), and 15
(0.12 g, 0.35 mmol). The crude product was purified by flash
column chromatography (CHCl3/acetone) to give the title com-
pound as
a
white solid (0.090 g, 61%); 1H NMR (270 MHz,
1
(0.34 g, 64%); mp: 97.5–98.58C; H NMR (270 MHz, CDCl3): d=7.79
[D6]DMSO): d=9.08 (2H, s, 2ꢁNCHN), 7.88 (2H, brs, NH2), 7.73 (2H,
AA’BB’, ArH), 7.13 (1H, d, J=9.0, ArH), 7.03–6.95 (2H, m, ArH), 6.66
(2H, AA’BB’, ArH), 3.88 (2H, d, J=6.9, CH2N), 3.00–2.65 (3H, m, CHH
and CH2), 2.60–2.50 (1H, m, CHH), 2.02–1.90 (1H, m, CHH), 1.80–
1.64 (1H, m, CHH), 1.58–1.40 ppm (1H, m, CHH); 13C NMR
(100 MHz, [D6]DMSO): d=152.5 (C), 148.5 (C), 144.0 (2ꢁCH), 138.1
(C), 134.4 (2ꢁCH), 134.2 (C), 130.5 (CH), 122.3 (CH), 120.0 (CH),
(2H, AA’BB’, ArH), 7.43–7.26 (7H, m, ArH), 6.91 (1H, d, J=8.4, ArH),
6.72 (1H, dd, J=8.4, 2.7, ArH), 6.67 (1H, d, J=2.7, ArH), 5.00 (2H, s,
CH2), 3.97 (2H, d, J=6.7, CH2), 2.81–2.69 (3H, m, CHH and CH2),
2.44 (3H, s, CH3), 2.35 (1H, dd, J=15.6, 10.6, CHH), 2.19–2.02 (1H,
m, CHH), 1.95–1.82 (1H, m, CHH), 1.45–1.30 ppm (1H, m, CHH);
13C NMR (100 MHz, CDCl3): d=157.0 (C), 144.8 (C), 137.2 (C), 133.0
1586
www.chemmedchem.org
ꢀ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemMedChem 2010, 5, 1577 – 1593

Bicyclic DASI Derivatives
119.6 (C), 113.7 (2ꢁCH), 102.8 (C), 59.4 (CH2), 33.0 (CH), 32.5 (CH2),
28.7 (CH2), 26.2 ppm (CH2); MS (APCI): m/z (%): 425.1 (100) [M+H]+,
346.2 (10), 214.0 (50), 162.9 (20), 158.8 (25); HRMS-FAB: m/z
[M+H]+ calcd for C20H21N6O3S: 425.1396, found: 425.1382; HPLC
(CH3CN/H2O, 60:40) tR =1.74 min (purity: >99%).
ture was stirred at 608C overnight. The reaction mixture was al-
lowed to cool, and was then poured onto a mixture of H2O
(200 mL) and CH2Cl2 (160 mL), and the layers were separated. The
aqueous layer was extracted with CH2Cl2 (100 mL), and the com-
bined organic layers were washed with H2O (4ꢁ150 mL), dried
(MgSO4), and the solvent was removed in vacuo. The crude prod-
uct was purified by triturating with portions of hot acetone (3ꢁ
50 mL) to give the title compound as a white powder (5.11 g,
70%); mp: 225–227.58C; 1H NMR (270 MHz, [D6]DMSO): d=8.83
(2H, s, 2ꢁNCHN), 7.82–7.71 (5H, m, ArH), 7.53–7.30 (7H, m, ArH),
6.80 (1H, dd, J=8.9, 2.5, ArH), 6.80 (2H, AA’BB’, ArH), 5.21 (2H, s,
CH2), 5.19 ppm (2H, s, CH2); 13C NMR (68 MHz, [D6]DMSO): d=157.1
(C), 152.2 (C), 144.0 (2ꢁCH), 137.4 (C), 134.5 (2ꢁCH), 134.4 (C),
130.4 (C), 129.9 (CH), 129.0 (2ꢁCH), 128.8 (C), 128.5 (CH), 128.4 (2ꢁ
CH), 127.9 (2ꢁCH), 127.2 (CH), 119.7 (CH), 119.6 (C), 114.3 (2ꢁCH),
107.8 (CH), 103.4 (C), 69.9 (CH2), 57.9 ppm (CH2); MS (FAB): m/z
(%):432.1 (70) [M]+, 363.1 (50), 247.1 (35), 91.0 (100); Anal. calcd for
C27H21N5O: C 75.16, H 4.91, N 16.23, found: C 75.30, H 4.96, N
16.30.
Benzyl 6-(benzyloxy)-2-naphthoate (18). 6-Hydroxy-2-napthoic
acid (8.00 g, 42.5 mmol) was added to a cooled (08C) suspension
of NaH (60% in mineral oil, 3.74 g, 93.5 mmol) in DMF (100 mL).
After stirring for 30 min, benzyl bromide (11.1 mL, 93.5 mmol) was
added, and the mixture was stirred overnight. The reaction mixture
was poured onto a mixture of H2O (100 mL) and EtOAc (100 mL),
and the layers were separated. The aqueous layer was extracted
with EtOAc (3ꢁ100 mL), and the combined organic layers were
washed with H2O (200 mL), dried (MgSO4), and the solvent was re-
moved in vacuo. The crude product was purified by recrystallisa-
tion from EtOAc/hexane to give the title compound as a white
crystalline solid (12.18 g, 78%); mp: 115–115.58C; 1H NMR
(270 MHz, [D6]DMSO): d=8.58 (1H, s, ArH), 8.05 (1H, d, J=8.9,
ArH), 8.00–7.85 (2H, m, ArH), 7.58–7.46 (5H, m, ArH), 7.45–7.27 (7H,
m, ArH), 5.39 (2H, s, OCH2), 5.24 ppm (2H, s, OCH2).
4-{[(6-Hydroxynaphthalen-2-yl)methyl](4H-1,2,4-triazol-4-yl)ami-
no}benzonitrile (22). As per general method A using 10% Pd/C
(0.31 g), 21 (2.15 g, 4.99 mmol) and THF/MeOH (1:1, 360 mL). The
crude product was purified by triturating with portions of hot ace-
tone (3ꢁ5 mL) to give the title compound as a white powder
[6-(Benzyloxy)naphthalen-2-yl]methanol (19). A solution of 18
(2.00 g, 5.4 mmol) in THF (30 mL) was slowly added to a suspen-
sion of LiAlH4 (0.23 g, 6.0 mmol) in THF (70 mL). The resulting mix-
ture was stirred for 2 h and then quenched by the cautious addi-
tion of EtOAc (15 mL) and H2O (15 mL). Additional EtOAc (140 mL)
and HCl(aq) (3m, 50 mL) were added, and the layers were separated.
The aqueous layer was extracted with EtOAc (3ꢁ40 mL), and the
combined organics were washed with brine (200 mL), dried
(MgSO4), and the solvent was removed in vacuo. The crude prod-
uct was recrystallised from EtOH to give the title compound as a
white solid (1.15 g, 81%); mp: 138.0–138.58C; 1H NMR (400 MHz,
CDCl3): d=7.75–7.69 (3H, m, ArH), 7.51–7.31 (5H, m, ArH), 7.25–
7.19 (2H, m ArH), 5.16 (2H, s, CH2), 4.79 (2H, d, J=5.9, CH2),
1.82 ppm (1H, t, J=5.9, OH); 13C NMR (100 MHz, CDCl3): d=157.0
(C), 137.0 (C), 136.2 (C), 134.2 (C), 129.6 (CH), 129.1 (C), 128.8 (2ꢁ
CH), 128.2 (CH), 127.7 (2ꢁCH), 127.4 (CH), 126.0 (CH), 125.7 (CH),
119.5 (C), 107.3 (CH), 70.3 (CH2), 65.8 ppm (CH2); MS (ES): m/z (%):
263.0 (80) [MꢀH]ꢀ), 211.9 (100); Anal. calcd for C18H16O2: C 81.79, H
6.10, found: C 81.77, H 6.11%.
1
(0.96 g, 56%); mp: 281–2848C; H NMR (270 MHz, [D6]DMSO): d=
9.82 (1H, brs, OH), 8.83 (2H, s, 2ꢁNCHN), 7.82–7.60 (5H, m, ArH),
7.35 (1H, dd, J=8.6, 1.5, ArH), 7.12–7.04 (2H, m, ArH), 6.80 (2H,
AA’BB’, ArH), 5.16 ppm (2H, s, CH2); 13C NMR (68 MHz, [D6]DMSO):
d=156.2 (C), 152.2 (C), 144.0 (2ꢁCH), 134.7 (C), 134.5 (2ꢁCH),
129.9 (CH), 129.2 (C), 127.9 (CH), 127.9 (C), 127.2 (CH), 126.9 (CH),
119.7 (C), 119.5 (CH), 114.3 (2ꢁCH), 109.1 (CH), 103.3 (C), 57.9 ppm
(CH2); MS (FAB): m/z (%): 342.1 (100) [M+H]+, 274.1 (40), 158.0
(25); HRMS-FAB: m/z [M+H]+ calcd for C20H16N5O: 342.1355, found:
342.1359; HPLC (CH3CN/H2O, 70:30) tR =1.74 min (purity: 98%).
6-{[(4-Cyanophenyl)(4H-1,2,4-triazol-4-yl)amino]methyl}naphtha-
len-2-yl sulfamate (23). As per general method B using H2NSO2Cl
(0.7m, 9.0 mL), DMA (10 mL) and 22 (0.90 g, 2.64 mmol). The crude
product was purified by recrystallisation from acetone/hexane to
give the title compound as a white solid (0.75 g, 68%); 1H NMR
(270 MHz, [D6]DMSO): d=8.86 (2H, s, 2ꢁNCHN), 8.08 (2H, s, NH2),
7.99–7.94 (2H, m, ArH), 7.87 (1H, s, ArH), 7.83–7.76 (3H, m, ArH),
7.57 (1H, dd, J=8.8, 1.8, ArH), 7.44 (1H, dd, J=8.8, 2.5, ArH), 6.81
(2H, AA’BB’, ArH), 5.26 ppm (2H, s, CH2); 13C NMR (68 MHz,
[D6]DMSO): d=152.2 (C), 148.6 (C), 144.0 (2ꢁCH), 134.6 (2ꢁCH),
133.4 (C), 133.2 (C), 131.6 (C), 130.3 (CH), 128.9 (CH), 127.9 (CH),
127.6 (CH), 122.7 (CH), 119.8 (CH), 119.6 (C), 114.4 (2ꢁCH), 103.5
(C), 57.9 ppm (CH2); MS (FAB): m/z (%): 421.1 (100) [M+H]+, 352.0
(58), 341.1 (10); HRMS-FAB: m/z [M+H]+ calcd for C20H17N6O3S:
421.1083, found: 421.1077; Anal. calcd for C20H16N6O3S.0.2% ace-
tone: C 57.30, H 4.06, N 19.32, found: C 57.30, H 4.09, N 19.40.
2-(Benzyloxy)-6-(chloromethyl)naphthalene (20). SOCl2 (4.56 g,
38.3 mmol) was added dropwise to a cooled (08C) solution of 19
(6.75 g, 25.6 mmol) in CH2Cl2 (130 mL). The resulting mixture was
stirred for 15 min then allowed to warm to room temperature and
stirred for 30 min. The solvent was removed in vacuo, and the resi-
due was dissolved in CH2Cl2 and evaporated, this process was re-
peated twice more. The crude product was purified by recrystallisa-
tion from EtOAc/hexane to give the title compound as a white
1
crystalline solid (5.16 g, 72%); mp: 145–1488C; H NMR (270 MHz,
[D6]DMSO): d=7.92–7.78 (3H, m, ArH), 7.59–7.22 (8H, m, ArH), 5.22
(2H, s, CH2), 4.90 ppm (2H, s, CH2); 13C NMR (68 MHz, [D6]DMSO):
d=157.4 (C), 137.4 (C), 134.5 (C), 133.3 (C), 130.1 (CH), 129.0 (2ꢁ
CH), 128.7 (C), 128.5 (CH), 128.5 (2ꢁCH), 128.2 (CH), 127.9 (CH),
127.8 (CH), 119.9 (CH), 107.8 (CH), 69.9 (CH2), 47.3 ppm (CH2); MS
(FAB): m/z (%): 281.2 (65) [M]+; HRMS-FAB: m/z [M+H]+ calcd for
C18H15OCl: 282.0811, found: 282.0801.
Methyl 6-hydroxy-2-naphthoate (24). A suspension of 6-hydroxy-
2-naphthoic acid (6.20 g, 33.0 mmol) in MeOH (125 mL) containing
HCl (concd, 10 drops) was heated at reflux overnight. The solution
was allowed to cool, and, following neutralisation with saturated
aqueous NaHCO3, the solvent was removed in vacuo. The residue
was dissolved in EtOAc (100 mL), washed with H2O (100 mL), satu-
rated aqueous NaHCO3 (100 mL), and brine (100 mL), then dried
(MgSO4), and the solvent was removed in vacuo. The title com-
pound was obtained as a beige powder (6.03 g, 91%); mp: 168–
1708C; 1H NMR (270 MHz, CDCl3): d=8.41 (1H, s, ArH), 7.86 (1H,
dd, J=8.6, 1.5, ArH), 7.74–7.70 (1H, m, ArH), 7.59 (1H, d, J=8.6,
ArH), 7.13–7.09 (2H, m, ArH), 3.87 ppm (3H, s, CH3).
4-({[6-(Benzyloxy)naphthalen-2-yl]methyl}(4H-1,2,4-triazol-4-yl)-
amino)benzonitrile (21). Compound 8 (3.27 g, 17.7 mmol) was
added in small portions to a cooled (08C) suspension of NaH (60%
in mineral oil, 0.78 g, 19.5 mmol) in DMF (150 mL). The resulting
solution was allowed to warm to room temperature, and after
30 min, 20 (4.75 g, 16.8 mmol) was added, and the reaction mix-
ChemMedChem 2010, 5, 1577 – 1593
ꢀ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemmedchem.org
1587

B. V. L. Potter et al.
MED
Methyl 5-chloro-6-hydroxy-2-naphthoate (25). SO2Cl2 (4.74 g,
35.1 mmol) was added to a suspension of 24 (6.45 g, 31.9 mmol) in
AcOH (95 mL), and the resulting mixture was stirred for 4 h. The
white precipitate was collected by filtration, washing with hexane
to give the title compound. The filtrate was concentrated in vacuo
to 20 mL and left to stand overnight. The solid formed was collect-
ed by filtration and washed with AcOH and hexane to give a fur-
ther portion of the product. The title compound was obtained as a
white solid (4.76 g, 63%); mp: 156–1578C; 1H NMR (270 MHz,
[D6]DMSO): d=10.87 (1H, s, OH), 8.50 (1H, s, ArH), 8.04–7.98 (2H,
m, ArH), 7.93 (1H, d, J=8.9, ArH), 7.31 (1H, d, J=8.9, ArH),
3.83 ppm (3H, s, CH3), MS (APCI): m/z (%): 235 (100) [M-1]ꢀ, 175
(15).
(C), 127.6 (CH), 127.6 (CH), 127.5 (CH), 124.7 (CH), 121.6 (CH), 118.9
(C), 46.4 (CH2), 18.0 (6ꢁCH3), 13.1 ppm (3ꢁCH); MS (APCI): m/z (%):
383.0 (15) [M+H]+, 347.1 (100); HRMS-FAB: m/z [M]+ calcd for
C20H28OSiCl2: 382.1287, found: 382.1280.
4-{[(5-Chloro-6-hydroxynaphthalen-2-yl)methyl](4H-1,2,4-triazol-
4-yl)amino}benzonitrile (30). Compound 8 (3.75 g, 20.2 mmol)
was added to a cooled (08C) suspension of NaH (60% in mineral
oil, 0.90 g, 22.5 mmol) in DMF (160 mL). After stirring at room tem-
perature for 1 h, 28 (7.00 g, 18.3 mmol) was added, and the reac-
tion mixture was stirred at room temperature for 48 h. TBAF (1m
in THF, 7.5 mL) was subsequently added, and after 20 min AcOH
(5 mL) was added. The reaction mixture was poured onto H2O
(200 mL) and extracted with EtOAc (2ꢁ150 mL). The combined or-
ganics were washed with H2O (4ꢁ100 mL) and brine (150 mL),
dried (MgSO4), and the solvent was removed in vacuo. The crude
product was purified by precipitation from THF with hexane to
give the title compound as a white powder (4.71 g, 69%); mp:
2708C; 1H NMR (270 MHz, [D6]DMSO): d=8.84 (2H, s, 2ꢁNCHN),
7.97 (1H, d, ArH), 7.84–7.70 (4H, m, ArH), 7.55 (1H, d, J=8.2, ArH),
7.28 (1H, d, J=8.6, ArH), 6.81 (2H, d, J=8.9, ArH), 5.21 (2H, s, CH2),
3.17 ppm (1H, s, OH); 13C NMR (100 MHz, [D6]DMSO): d=156.9 (2ꢁ
C), 148.7 (2ꢁCH), 139.3 (2ꢁCH), 136.4 (C), 135.1 (C), 133.4 (CH),
133.3 (CH), 133.1 (CH), 128.2 (CH), 124.5 (CH), 124.3 (C), 119.2 (2ꢁ
CH), 117.7 (C), 108.3 (2ꢁC), 62.6 ppm (CH2); MS (ES): m/z (%): 374.3
(30) [MꢀH]ꢀ, 305.2 (8), 184.0 (100), 140.8 (90), 101.9 (70); HRMS-
FAB: m/z [M]+ calcd for C20H15N5OCl: 376.0965, found: 376.0963;
HPLC (CH3CN/H2O, 90:10) tR =1.91 min (purity: >99%).
Methyl 5-chloro-6-(triisopropylsilyloxy)-2-naphthoate (26). Imida-
zole (4.32 g, 63.5 mmol) and TIPSCl (7.33 g, 37.9 mmol) were se-
quentially added to a solution of 25 (7.50 g, 31.6 mmol) in DMF
(80 mL). The reaction mixture was stirred overnight, then poured
onto H2O (150 mL) and extracted with EtOAc (3ꢁ75 mL). The com-
bined organics were washed with H2O (3ꢁ100 mL) and brine
(100 mL), then dried (MgSO4), and the solvent was removed in va-
cuo. The crude crystalline product was heated in a small amount
of MeOH, then the crystals were collected by filtration, washing
with hexane, to give the title compound as colourless crystals
(11.04 g, 93%); mp: 88–908C; 1H NMR (270 MHz, CDCl3): d=8.51
(1H, d, J=1.5, ArH), 8.21 (1H, d, J=8.9, ArH), 8.09 (1H, dd, J=8.9,
1.5, ArH), 7.74 (1H, d, J=8.9, ArH), 7.19 (1H, d, J=8.9, ArH), 3.96
(3H, s, CH3), 1.42–1.12 ppm (21H, m, 6ꢁCH3, 3ꢁCH); 13C NMR
(100 MHz, CDCl3): d=167.5 (C), 154.0 (C), 135.2 (C), 131.1 (CH),
129.0 (CH), 128.7 (C), 126.6 (CH), 125.2 (C), 124.0 (CH), 121.7 (CH),
119.5 (C), 52.3 (CH3), 18.0 (6ꢁCH3), 13.1 ppm (3ꢁCH); MS (APCI):
m/z (%): 392.6 (85) [M+H]+, 213.5 (30), 157.4 (90), 140.4 (100);
HRMS-FAB: m/z [M+H]+ calcd for C21H30O3SiCl: 393.1653, found:
393.1641; Anal. calcd for C21H29O3SiCl: C 64.18, H 7.44, found: C
64.15, H 7.40.
1-Chloro-6-{[(4-cyanophenyl)(4H-1,2,4-triazol-4-yl)amino]methyl}-
naphthalen-2-yl sulfamate (31). As per general method B using
H2NSO2Cl (0.7m, 7.0 mL), DMA (7.0 mL), and 30 (0.21 g, 0.56 mmol).
The crude product was purified by recrystallisation from acetone/
hexane to give the title compound as a white solid (0.21 g, 83%);
1H NMR (270 MHz, [D6]DMSO): d=8.89 (2H, s, 2ꢁNCHN), 8.33 (2H,
s, NH2), 8.21 (1H, d, J=8.6, ArH), 8.06–7.93 (2H, m, ArH), 7.87–7.63
(4H, m, ArH), 6.82 (2H, d, J=8.6, ArH), 5.31 ppm (2H, s, CH2);
13C NMR (68 MHz, [D6]DMSO): d=152.1 (C), 144.8 (C), 144.0 (2ꢁCH),
134.6 (2ꢁCH), 134.2 (C), 132.4 (C), 130.8 (C), 129.0 (2ꢁCH), 128.4
(CH), 125.2 (CH), 123.4 (C), 123.1 (CH), 119.6 (C), 114.3 (2ꢁCH),
103.6 (C), 57.5 ppm (CH2); MS (FAB): m/z (%): 454.9 (100) [M+H]+;
HRMS-FAB: m/z [M]+ calcd for C20H16N6O3SCl: 455.0693, found:
455.0690; HPLC (CH3CN/H2O, 90:10) tR =1.52 min (purity: 99%).
[5-Chloro-6-(triisopropylsilyloxy)naphthalen-2-yl]methanol (27).
LiBH4 (1.47 g, 66.8 mmol) and B(OMe)3 (0.28 g, 2.69 mmol) were se-
quentially added to a stirred solution of 26 (10.50 g, 26.7 mmol) in
Et2O (200 mL). The reaction mixture was stirred overnight and then
quenched by the cautious addition of H2O (75 mL). The layers were
separated and the organic layer was washed with HCl(aq) (3m,
75 mL), H2O (75 mL), and brine (75 mL), then dried (MgSO4), and
the solvent was removed in vacuo. The title compound was ob-
1
5-bromo-6-hydroxy-2-naphthoic acid (32). Bromine (2.06 g,
12.9 mmol) was slowly added to a solution of 6-hydroxy-2-naph-
thoic acid (2.00 g, 10.6 mmol) in THF (30 mL). After stirring over-
night, the reaction mixture was poured onto H2O (80 mL), and the
precipitate was collected by filtration. The residue was dissolved in
EtOAc and precipitated with hexane to give the title compound as
a yellow solid (2.32 g, 82%); 1H NMR (400 MHz, [D6]DMSO): d=
12.98 (1H, brs, CO2H), 10.96 (1H, s, OH), 8.51 (1H, s, ArH), 8.06–7.98
(3H, m, ArH), 7.32 ppm (1H, d, J=9.0, ArH).
tained as a colourless oil (10.20 g, 99%); H NMR (270 MHz, CDCl3):
d=8.18 ((1H, d, J=8.7, ArH), 7.72 (1H, s, ArH), 7.61 (1H, d, J=8.8,
ArH), 7.51 (1H, dd, J=8.9, 1.7, ArH), 7.12 (1H, d, J=8.9, ArH), 4.82
(2H, d, J=5.5, CH2), 1.75 (1H, t, J=5.5, OH), 1.41–1.05 ppm (21H,
m, 6ꢁCH3, 3ꢁCH); 13C NMR (100 MHz, [D6]DMSO): d=149.8 (C),
136.7 (C), 131.8 (C), 129.5 (C), 127.4 (CH), 126.5 (CH), 125.6 (CH),
124.3 (CH), 121.3 (CH), 119.4 (C), 65.2 (CH2), 18.0 (6ꢁCH3), 13.1 ppm
(3ꢁCH); MS (APCI): m/z (%): 364.3 (5) [M]+, 346.8 (100); HRMS-FAB:
m/z [M]+ calcd for C20H29O2SiCl: 364.1625, found: 364.1627.
[1-Chloro-6-(chloromethyl)naphthalen-2-yloxy]triisopropylsilane
(28). SOCl2 (9.39 g, 78.9 mmol) was added dropwise to a stirred so-
lution of 27 (9.60 g, 26.3 mmol) in CH2Cl2 (200 mL). The resulting
mixture was stirred for 4.5 h, then the solvent was removed in va-
cuo, and the residue was re-dissolved in CH2Cl2 and evaporated,
this process was repeated twice more. The title compound was ob-
Methyl 5-bromo-6-hydroxy-2-naphthoate (33). A suspension of
32 (1.28 g, 4.79 mmol) and HCl (concd, 5 drops) in MeOH (30 mL)
was heated at reflux overnight. The solution was allowed to cool
and, following neutralisation with saturated aqueous NaHCO3, the
solvent was removed in vacuo. The residue was dissolved in EtOAc
(60 mL), washed with H2O (70 mL), saturated aqueous NaHCO3
(70 mL), and brine (70 mL), then dried (MgSO4), and the solvent
was removed in vacuo. The crude product was purified using
Flashmaster II (EtOAc/hexane) to give the title compound as a
1
tained as a colourless oil (8.80 g, 87%); H NMR (270 MHz, CDCl3):
d=8.19 (1H, d, J=8.9, ArH), 7.74 (1H, d, J=1.7, ArH), 7.61 (1H, d,
J=8.6, ArH), 7.54 (1H, dd, J=8.6, 1.7, ArH), 7.15 (1H, d, J=8.9,
ArH), 4.72 (2H, s, CH2), 1.42–1.00 ppm (21H, m, 6ꢁCH3, 3ꢁCH);
13C NMR (100 MHz, CDCl3): d=150.3 (C), 133.2 (C), 132.0 (C), 129.3
1
white solid (1.05 g, 78%); H NMR (270 MHz, [D6]DMSO): d=11.06
(1H, brs, OH), 8.55 (1H, d, J=1.2, ArH), 8.11–7.99 (3H, m, ArH), 7.35
1588
www.chemmedchem.org
ꢀ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemMedChem 2010, 5, 1577 – 1593

Bicyclic DASI Derivatives
(1H, d, J=8.6, ArH), 3.89 ppm (3H, s, CH3); MS (APCI) 278.9 (100)
[M]ꢀ.
EtOAc (2ꢁ100 mL). The combined organics were washed with H2O
(4ꢁ80 mL) and brine (80 mL), dried (MgSO4), and the solvent was
removed in vacuo. The crude product was purified by trituration
with hot acetone (3ꢁ15 mL). The combined triturates were con-
centrated in vacuo and purified using Flashmaster II (EtOAc/
Hexane) to give a further portion of the title compound and some
TIPS-protected product 37 (which could be deprotected with
TBAF). The title compound was obtained as an off-white solid
Methyl 5-bromo-6-(triisopropylsilyloxy)-2-naphthoate (34). Imi-
dazole (0.19 g, 2.80 mmol) and TIPSCl (0.33 g, 1.71 mmol) were se-
quentially added to
a pale-yellow solution of 33 (0.40 g,
1.42 mmol) in DMF (4 mL). The reaction mixture was stirred over-
night, then poured onto H2O (15 mL) and extracted with EtOAc
(3ꢁ15 mL). The combined organics were washed with H2O (3ꢁ
15 mL) and brine (15 mL), then dried (MgSO4), and the solvent was
removed in vacuo. The crude product was purified using Flashmas-
ter II (EtOAc/hexane) to give the title compound as an oil which
1
(0.52 g, 36%); mp: 2508C (dec.); H NMR (270 MHz, [D6]DMSO): d=
10.63 (1H, s, OH), 8.85 (2H, s, 2ꢁNCHN), 7.96 (1H, d, J=8.6, ArH),
7.81–7.72 (4H, m, ArH), 7.54 (1H, dd, J=8.6, 1.7, ArH), 7.26 (1H, d,
J=8.6, ArH), 6.81 (2H, AA’BB’, ArH), 5.21 ppm (2H, s, CH2); 13C NMR
(100 MHz, [D6]DMSO): d=153.4 (C), 152.1 (C), 143.9 (2ꢁCH), 134.5
(2ꢁCH), 132.9 (C), 130.1 (C), 129.4 (CH), 128.7 (C), 128.4 (2ꢁCH),
125.9 (CH), 119.5 (CH), 119.2 (C), 114.2 (2ꢁCH), 106.7 (C), 103.4 (C),
57.5 ppm (CH2); MS (APCI) 420.1 (100) [M+H]+, 351.1 (30), 273.2
(20), 259.1 (20); HRMS-FAB: m/z [M]+ calcd for C20H15N5OBr:
420.0460, found: 420.0450; HPLC (CH3CN/H2O, 90:10) tR =1.84 min
(purity: >99%).
1
solidified on standing (0.61 g, 98%); H NMR (270 MHz, CDCl3): d=
8.50 (1H, s, ArH), 8.22 (1H, d, J=8.9, ArH), 8.08 (1H, d, J=8.9, ArH),
7.77 (1H, d, J=8.9, ArH), 7.17 (1H, d, J=8.9, ArH), 3.96 (3H, s, CH3),
1.44–1.04 ppm (21H, m, 6ꢁCH3, 3ꢁCH); 13C NMR (100 MHz,
[D6]DMSO): d=153.1 (C), 135.9 (C), 131.0 (CH), 130.0 (CH), 128.7 (C),
126.8 (CH), 126.7 (CH), 125.8 (C), 121.3 (CH), 111.6 (C), 110.0 (C),
52.3 (CH3), 18.0 (6ꢁCH3), 13.2 ppm (3ꢁCH); MS (APCI): m/z (%):
437.2 (100) [M+H]+; HRMS-FAB: m/z [M]+ calcd for C21H30O3SiBr:
437.1148, found: 437.1149.
1-Bromo-6-{[(4-cyanophenyl)(4H-1,2,4-triazol-4-yl)amino]methyl}-
naphthalen-2-yl sulfamate (39). As per general method B using
H2NSO2Cl (0.7m, 3.75 mL), DMA (4.0 mL), and 38 (0.36 g,
0.86 mmol). The crude product was purified by flash column chro-
matography (CH2Cl2/acetone, 3:1) to give the title compound as a
white solid (0.21 g, 51%); 1H NMR (270 MHz, [D6]DMSO): d=8.87
(2H, s, 2ꢁNCHN), 8.33 (2H, brs, NH2), 8.18 (1H, d, J=8.6, ArH), 8.02
(1H, d, J=8.6, ArH), 7.94 (1H, s, ArH), 7.82–7.70 (3H, m, ArH), 7.65
(1H, d, J=8.9, ArH), 6.81 (2H, AA’BB’, ArH), 5.30 ppm (2H, s, CH2);
13C NMR (100 MHz, [D6]DMSO): d=152.0 (C), 146.5 (C), 143.9 (2ꢁ
CH), 134.5 (2ꢁCH), 134.0 (C), 132.3 (C), 132.1 (C), 129.7 (CH), 129.1
(CH), 128.3 (CH), 127.8 (CH), 122.7 (CH), 119.5 (C), 115.2 (C), 114.3
(2ꢁCH), 103.5 (C), 57.4 ppm (CH2); MS (APCI): m/z (%): 499.1 (10)
[M+H]+, 430.1 (50), 351.1 (80), 159.0 (100); HRMS-FAB: m/z
[M+H]+ calcd for C20H16N6O3SBr: 499.0188, found: 499.0177; HPLC
(CH3CN/H2O, 80:20) tR =1.70 min (purity: >99%).
[5-Bromo-6-(triisopropylsilyloxy)naphthalen-2-yl]methanol (35).
LiBH4 (0.032 g, 1.45 mmol) and B(OMe)3 (0.006 g, 0.057 mmol) were
sequentially added to a solution of 34 (0.25 g, 0.57 mmol) in Et2O
(5 mL). The reaction mixture was stirred overnight and was then di-
luted with Et2O (15 mL) and quenched by the cautious addition of
H2O (15 mL). The layers were separated and the organic layer was
washed with HCl(aq) (3m, 15 mL), H2O (15 mL), and brine (15 mL),
then dried (MgSO4), and the solvent was removed in vacuo. The
crude product was purified using Flashmaster II (EtOAc/hexane) to
1
give the title compound as a colourless oil (0.16 g, 69%); H NMR
(270 MHz, CDCl3): d=8.18 ((1H, d, J=8.7, ArH), 7.71 (1H, s, ArH),
7.65 (1H, d, J=8.9, ArH), 7.51 (1H, dd, J=8.7, 1.7, ArH), 7.14 (1H, d,
J=8.9, ArH), 4.83 (2H, s, CH2), 1.40–1.10 ppm (21H, m, 6ꢁCH3, 3ꢁ
CH); 13C NMR (100 MHz, [D6]DMSO): d=151.1 (C), 136.7 (C), 133.1
(C), 129.7 (C), 128.4 (CH), 127.0 (CH), 126.8 (CH), 125.6 (CH), 121.0
(CH), 111.6 (C), 65.2 (CH2), 18.1 (6ꢁCH3), 13.2 ppm (3ꢁCH); MS
(APCI): m/z (%): 409.2 (35) [M]+, 393.2 (100); HRMS-ES: m/z
[M+NH4]+ calcd for C20H33O2NSiBr: 426.1458, found: 426.1461.
2-[5-(Benzyloxy)-1H-indol-1-yl]ethanol (41). NaH (60%, 0.32 g,
8.06 mmol) was added in small portions to a solution of 5-benzy-
loxyindole (1.50 g, 6.72 mmol) in DMF (25 mL). After stirring for
30 min, ethylene carbonate (0.89 g, 10.1 mmol) was added, and
the resulting mixture was stirred overnight. The mixture was
poured onto H2O (60 mL) and extracted with EtOAc (3ꢁ60 mL).
The combined organic layers were washed with H2O (3ꢁ60 mL)
and brine (60 mL), then dried (MgSO4), and the solvent was re-
moved in vacuo. The crude product was purified using Flashmaster
II (EtOAc/hexane) to give the title compound as an oil which solidi-
[1-Bromo-6-(chloromethyl)naphthalen-2-yloxy]triisopropylsilane
(36). SOCl2 (1.44 g, 12.1 mmol) added dropwise to a stirred solution
of 35 (1.65 g, 4.40 mmol) in CH2Cl2 (60 mL). The resulting mixture
was stirred for 4.5 h, then the solvent was removed in vacuo, and
the residue was re-dissolved in CH2Cl2 and evaporated; this process
was repeated twice more. The title compound (1.69 g, 95%) was
1
1
obtained as an oil which solidified on standing; H NMR (270 MHz,
fied on standing (1.24 g, 69%); H NMR (270 MHz, [D6]DMSO): d=
CDCl3): d=8.20 (1H, d, J=8.6, ArH), 7.73 (1H, d, J=1.5, ArH), 7.65
(1H, d, J=8.6, ArH), 7.54 (1H, dd, J=8.6, 1.5, ArH), 7.15 (1H, d, J=
8.6, ArH), 4.73 (2H, s, CH2), 1.44–1.14 ppm (21H, m, 6ꢁCH3, 3ꢁCH);
13C NMR (100 MHz, [D6]DMSO): d=151.6 (C), 133.3 (C), 133.2 (C),
129.4 (C), 128.5 (CH), 127.9 (CH), 127.6 (CH), 127.4 (CH), 121.2 (CH),
111.7 (C), 46.3 (CH2), 18.0 (6ꢁCH3), 13.2 ppm (3ꢁCH); MS (FAB): m/z
(%): 426.1 (45) [M]+, 393.0 (90), 384.9 (100), 382.9 (55); HRMS-FAB:
m/z [M]+ calcd for C20H28OSiClBr: 426.0781, found: 426.0780.
7.52–7.48 (2H, m, ArH), 7.44–7.39 (2H, m, ArH), 7.37–7.33 (1H, m,
ArH), 7.24 (1H, d, J=8.4, ArH) 7.19 (1H, d, J=2.0, ArH), 7.10 (1H, d,
J=3.2, ArH), 7.00 (1H, dd, J=8.4, 2.0, ArH), 6.43 (1H, dd, J=3.2,
0.8, ArH), 5.13 (2H, s, CH2), 4.15 (2H, t, J=4.8, NCH2), 3.82 (2H, t,
J=5.2, CH2OH), 1.92 ppm (1H, brs, OH); 13C NMR (100 MHz,
[D6]DMSO): d=153.4 (C), 137.9 (C), 131.8 (2ꢁC), 129.2 (CH), 128.8
(2ꢁCH), 128.0 (CH), 127.8 (2ꢁCH), 113.0 (CH), 110.4 (CH), 104.6
(CH), 101.3 (CH), 71.2 (CH2), 62.2 (CH2), 49.2 ppm (CH2); MS (ES):
m/z (%): 268.2 (10) [M+H]+, 240.2 (50), 214.2 (70); HRMS-FAB: m/z
[M+H]+ calcd for C17H18NO2: 268.1332, found: 268.1321.
4-{[(5-Bromo-6-hydroxynaphthalen-2-yl)methyl](4H-1,2,4-triazol-
4-yl)amino}benzonitrile (38). Compound 8 (0.76 g, 4.11 mmol)
was added in small portions to a cooled (08C) suspension of NaH
(60% in mineral oil, 0.18 g, 4.50 mmol) in DMF (35 mL). The result-
ing solution was allowed to warm to room temperature, and after
30 min, a solution of 36 (1.46 g, 3.43 mmol) in DMF (10 mL) was
added, and the reaction mixture was stirred overnight. The reac-
tion mixture was poured onto H2O (100 mL) and extracted with
2-[5-(Benzyloxy)-1H-indol-1-yl]ethyl-4-methylbenzenesulfonate
(42). p-Toluenesulfonyl chloride (0.32 g, 1.68 mmol) was added to a
cooled (08C) solution of 41 (0.30 g, 1.12 mmol) and pyridine
(0.18 g, 2.27 mmol) in CHCl3 (3 mL). After 1 h, the reaction mixture
was allowed to warm to room temperature and stirred overnight.
The solvent was removed in vacuo, and the crude product was pu-
ChemMedChem 2010, 5, 1577 – 1593
ꢀ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemmedchem.org
1589

B. V. L. Potter et al.
MED
rified using Flashmaster II (EtOAc/hexane) to give the title com-
pound as
6.51 (1H, d, J=3.0, ArH), 6.40 (2H, AA’BB’, ArH), 4.47 (2H, t, J=5.2,
CH2), 4.25 ppm (2H, t, J=5.2, CH2); MS (ES) (APCI): m/z (%): 424.2
(85) [M+H]+, 355.2 (25), 224.9 (100), 157.8 (20), 140.8 (15); HRMS-
FAB: m/z [M+H]+ calcd for C19H18N7O3S: 424.1192, found: 424.1187;
HPLC (CH3CN/H2O, 70:30) tR =1.84 min (purity: 99%).
a
white solid (0.42 g, 90%); 1H NMR (400 MHz,
[D6]DMSO): d=7.50–7.45 (4H, m, ArH), 7.42–7.37 (2H, m, ArH),
7.36–7.30 (1H, m, ArH), 7.12 (1H, d, J=2.4, ArH), 7.08 (2H, d, J=
8.4, ArH), 7.02 (1H, d, J=9.2, ArH), 6.98 (1H, d, J=3.2, ArH), 6.87
(1H, dd, J=8.4, 2.4, ArH), 6.34 (1H, d, J=3.2, ArH), 5.10 (2H, s,
OCH2), 4.33 (2H, t, J=5.6, NCH2), 4.27 (2H, t, J=5.6, CH2), 2.36 ppm
(3H, s, CH3); 13C NMR (100 MHz, [D6]DMSO): d=153.5 (C), 145.0 (C),
137.8 (C), 132.0 (C), 131.2 (C), 129.6 (2ꢁCH), 129.3 (C), 128.9 (CH),
128.7 (2ꢁCH), 128.0 (CH), 127.8 (2ꢁCH), 127.0 (2ꢁCH), 112.9 (CH),
109.8 (CH), 104.5 (CH), 101.9 (CH), 71.1 (CH2), 68.2 (CH2), 45.7 (CH2),
22.0 ppm (CH3); MS (ES): m/z (%): 422.1 (50) [M+H]+, 123.6 (100);
HRMS-FAB: m/z [M]+ calcd for C24H23NO4S: 421.1348, found:
421.1339.
2-[5-(Benzyloxy)-1H-indol-3-yl]ethanol (47). A solution of 2-[5-
(benzyloxy)-1H-indol-3-yl]-2-oxoacetyl
chloride[34]
(0.80 g,
2.55 mmol) in THF (10 mL) was added dropwise to a suspension of
LiAlH4 (0.38 g, 10 mmol) in THF (20 mL). After heating at reflux for
5 h, the reaction mixture was allowed to cool and was quenched
by the cautious addition of EtOAc (15 mL), H2O (15 mL) and HCl(aq)
(3m, 15 mL). The product was extracted with EtOAc (2ꢁ20 mL),
and the combined organic layers were washed with brine (60 mL),
dried (MgSO4), and the solvent was removed in vacuo. The crude
product was purified using Flashmaster II (EtOAc/hexane) to give
the title compound as an off-white solid (0.46 g, 68%); 1H NMR
(270 MHz, [D6]DMSO): d=8.10 (1H, brs, NH), 7.55–7.46 (2H, m,
ArH), 7.45–7.30 (3H, m, ArH), 7.25–7.15 (2H, m, ArH), 7.00–6.92 (2H,
m, ArH), 5.11 (2H, s, CH2), 3.87 (2H, t, J=6.3, CH2CH2OH), 2.98 (2H,
t, J=6.3, CH2OH), 1.83 ppm (1H, s, OH); MS (APCI): m/z (%): 268.0
(10) [M+H]+, 250.1 (25), 236.1 (100).
4-({2-[5-(Benzyloxy)-1H-indol-1-yl]ethyl}(4H-1,2,4-triazol-4-yl)ami-
no)benzonitrile (43). Compound 42 (0.35 g, 0.83 mmol) was
added to a mixture of 8 (0.15 g, 0.81 mmol) and K2CO3 (0.29 g,
2.10 mmol) in DMF (8 mL). After stirring overnight, the mixture was
heated at 708C and stirred for 4 h. The resulting solution was
poured onto H2O (50 mL), and the product was extracted with
EtOAc (2ꢁ30 mL). The combined organic layers were washed with
H2O (4ꢁ50 mL) and brine (50 mL), then dried (MgSO4), and the sol-
vent was removed in vacuo. The crude product was purified using
Flashmaster II (EtOAc/hexane) to give the title compound as a
white solid (0.24 g, 68%); mp: 206.5–207.58C; 1H NMR (270 MHz,
[D6]DMSO): d=8.51 (2H, s, 2ꢁNCHN), 7.64 (2H, d, J=9.2, ArH),
7.52–7.45 (2H, m, ArH), 7.44–7.25 (5H, m, ArH), 7.17 (1H, d, J=2.5,
ArH), 6.85 (1H, dd, J=8.9, 2.2, ArH), 6.42–6.35 (3H, m, ArH), 5.10
(2H, s, OCH2), 4.43 (2H, t, J=5.7, NCH2), 4.23 ppm (2H, t, J=5.7,
CH2); 13C NMR (100 MHz, [D6]DMSO): d=153.2 (C), 151.0 (C), 143.7
(2ꢁCH), 138.3 (C), 134.5 (2ꢁCH), 131.6 (C), 130.1 (CH), 129.2 (C),
129.0 (2ꢁCH), 128.3 (3ꢁCH), 119.7 (C), 113.1 (2ꢁCH), 112.8 (CH),
110.9 (CH), 104.6 (CH), 103.0 (C), 101.7 (CH), 70.5 (CH2), 55.3 (CH2),
44.1 ppm (CH2); MS (ES) 435.3 (60) [M+H]+, 366.2 (70), 236.0 (100),
157.8 (20); HRMS-FAB: m/z [M]+ calcd for C26H23N6O: 435.1933,
found: 435.1923.
5-(benzyloxy)-3-(2-bromoethyl)-1-methyl-1H-indole (49). K2CO3
(0.60 g, 4.35 mmol) was added to a solution of 5-(benzyloxy)-3-(2-
bromoethyl)-1H-indole[35] (0.72 g, 2.19 mmol) and CH3I (1.86 g,
13.1 mmol) in DMF (21 mL). After stirring overnight, the reaction
mixture was added to H2O (50 mL), and the product was extracted
with EtOAc (2ꢁ50 mL). The combined organic layers were washed
with H2O (4ꢁ60 mL) and brine (60 mL), dried (MgSO4), and the sol-
vent was removed in vacuo. The crude product was purified using
Flashmaster II (EtOAc/hexane) to give the title compound as a
thick oil which solidified on standing (0.39 g, 52%); 1H NMR
(270 MHz, CDCl3): d=7.52–7.30 (5H, m, ArH), 7.20 (1H, d, J=8.6,
ArH), 7.09 (1H, d, J=2.2, ArH), 6.97 (1H, dd, J=8.6, 2.2, ArH), 6.90
(1H, s, ArH), 5.12 (2H, s, CH2), 3.72 (3H, s, CH3), 3.40–3.27 ppm (4H,
m, 2ꢁCH2); 13C NMR (100 MHz, CDCl3): d=153.1 (C), 137.6 (C),
132.6 (C), 128.6 (2ꢁCH), 127.9 (CH), 127.7 (2ꢁCH), 127.5 (C), 127.4
(CH), 113.5 (C), 112.7 (CH), 110.2 (CH), 102.3 (CH), 71.1 (CH2), 32.9
(CH3), 30.4 (CH2), 6.40 ppm (CH2); MS (APCI): m/z (%): 344.2 (100)
[M+H]+, 264.1 (75), 157.9 (90); HRMS-FAB: m/z [M+H]+ calcd for
C18H18NOBr: 343.0572, found: 343.0583.
4-{[2-(5-Hydroxy-1H-indol-1-yl)ethyl](4H-1,2,4-triazol-4-yl)amino}-
benzonitrile (44). As per general method A using 10% Pd/C
(90 mg), 43 (0.40 g, 0.92 mmol) and THF/MeOH (1:1, 50 mL). The
crude product was purified using Flashmaster II (EtOAc/hexane/
MeOH) [the desired product was contaminated with triazole which
could be washed out with H2O] to give the title compound as an
1
4-({2-[5-(Benzyloxy)-1-methyl-1H-indol-3-yl]ethyl}(4H-1,2,4-tria-
off-white solid (0.16 g, 51%); mp: 214–215.58C; H NMR (270 MHz,
zol-4-yl)amino)benzonitrile (50). Compound
8
(0.050 g,
[D6]DMSO): d=8.76 (1H, s, OH), 8.44 (2H, s, 2ꢁNCHN), 7.66 (2H,
AA’BB’, ArH), 7.28 (1H, d, J=3.0, ArH), 7.12 (1H, d, J=8.6, ArH),
6.88 (1H, d, J=3.0, ArH), 6.61 (1H, dd, J=8.6, 3.0, ArH), 6.39 (2H,
AA’BB’, ArH), 6.26 (1H, d, J=3.0, ArH), 4.38 (2H, t, J=5.9, CH2),
4.22 ppm (2H, t, J=5.9, CH2); 13C NMR (100 MHz, [D6]DMSO): d=
151.5 (C), 151.0 (C), 143.7 (2ꢁCH), 134.5 (2ꢁCH), 130.8 (C), 129.7
(CH), 129.6 (C), 119.7 (C), 113.1 (2ꢁCH), 112.3 (CH), 110.4 (CH),
105.2 (CH), 102.9 (C), 101.1 (CH), 55.2 (CH2), 44.0 ppm (CH2); MS
(ES): m/z (%): 345.2 (80) [M+H]+, 292.1 (15), 276.1 (100); HRMS-
FAB: m/z [M]+ calcd for C19H16N6O: 344.1386, found: 344.1372;
HPLC (CH3CN/H2O, 80:20) tR =1.83 min (purity: 97.3%).
0.27 mmol) was added in small portions to a cooled (08C) suspen-
sion of NaH (60% in mineral oil, 0.011 g, 0.27 mmol) in DMF
(1.5 mL). The resulting solution was allowed to warm to room tem-
perature, and after 30 min, a solution of 49 (0.084 g, 0.24 mmol) in
DMF (1.5 mL) was added. After stirring overnight, the resulting mix-
ture was poured onto H2O (20 mL) and extracted with EtOAc (2ꢁ
15 mL). The combined organic layers were washed with H2O (3ꢁ
20 mL) and brine (20 mL), then dried (MgSO4), and the solvent was
removed in vacuo. The crude product was purified using Flashmas-
ter II (EtOAc/hexane) to give the title compound as a white solid
(0.089 g, 81%); 1H NMR (400 MHz, [D6]DMSO): d=8.90 (2H, s, 2ꢁ
NCHN), 7.73 (2H, AA’BB’, ArH), 7.50–7.32 (6H, m, ArH), 7.20 (1H, s,
ArH), 7.04 (1H, d, J=2.3, ArH), 6.88 (1H, dd, J=8.7, 2.3, ArH), 6.63
(2H, AA’BB’, ArH), 5.07 (2H, s, OCH2), 4.10 (2H, t, J=7.6, CH2), 3.71
(3H, s, CH3), 2.89 ppm (2H, t, J=7.6, CH2); 13C NMR (100 MHz,
[D6]DMSO): d=152.7 (C), 151.5 (C), 144.1 (2ꢁCH), 138.1 (C), 134.4
(2ꢁCH), 132.6 (C), 128.9 (C), 128.8 (2ꢁCH), 128.1 (3ꢁCH), 128.0 (C),
119.6 (CH), 113.5 (2ꢁCH), 112.4 (CH), 110.0 (CH), 109.3 (C), 102.6
(C), 102.2 (CH), 70.3 (CH2), 54.2 (CH2), 32.9 (CH3), 22.6 ppm (CH2);
1-{2-[(4-Cyanophenyl)(4H-1,2,4-triazol-4-yl)amino]ethyl}-1H-
indol-5-yl sulfamate (45). As per general method B using
H2NSO2Cl (0.7m, 1.71 mL), DMA (3.0 mL), and 44 (0.10 g,
0.29 mmol). The crude product was purified using Flashmaster II
(EtOAc/hexane/MeOH) to give the title compound as an off-white
1
solid (0.034 g, 28%); H NMR (270 MHz, [D6]DMSO): d=8.64 (2H, s,
2ꢁNCHN), 7.82 (2H, brs, 2ꢁNH2), 7.66 (2H, AA’BB’, ArH), 7.54 (1H,
d, J=3.0, ArH), 7.50–7.42 (2H, m, ArH), 7.05 (1H, d, J=8.8, ArH),
1590
www.chemmedchem.org
ꢀ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemMedChem 2010, 5, 1577 – 1593

Bicyclic DASI Derivatives
1
MS (APCI): m/z (%): 449.2 (100) [M+H]+, 380.2 (80); HRMS-FAB: m/z
[M]+ calcd for C27H24N6O: 448.2012, found: 448.2012.
compound as a dusty red solid (0.055 g, 47%); H NMR (270 MHz,
[D6]DMSO): d=10.75 (1H, brs, NH), 8.70 (1H, s, OH), 8.51 (2H, s, 2ꢁ
NCHN), 7.79 (2H, AA’BB’, ArH), 7.15–7.04 (2H, m, ArH), 6.87 (2H,
AA’BB’, ArH), 6.80 (1H, s, CH), 6.62 (1H, d, J=8.8, ArH), 5.08 ppm
(2H, s, CH2); 13C NMR (100 MHz, [D6]DMSO): d=152.3 (C), 151.4 (C),
144.0 (2ꢁCH), 134.5 (2ꢁCH), 131.3 (C), 127.8 (C), 127.0 (CH), 119.8
(C), 114.5 (2ꢁCH), 112.7 (CH), 112.5 (CH), 106.8 (CH), 103.1 (C),
102.8 (C), 49.9 ppm (CH2); MS (ES+) 331.2 ([M+H]+, 30%), 262.1
(25), 85.1 (100); HRMS-FAB: m/z [M+H]+ calcd for C18H15N6O:
331.1307, found: 331.1295; HPLC (CH3CN/H2O, 90:10) tR =1.80 min
(purity: 98.8%).
4-{[2-(5-Hydroxy-1-methyl-1H-indol-3-yl)ethyl](4H-1,2,4-triazol-4-
yl)amino}benzonitrile (51). As per general method A using 10%
Pd/C (33 mg), 50 (0.30 g, 0.67 mmol) and THF/MeOH (1:1, 60 mL).
The crude product was purified using Flashmaster II (EtOAc/
hexane/MeOH) to give the title compound as a white solid (0.17 g,
71%); 1H NMR (270 MHz, [D6]DMSO): d=8.92 (2H, s, 2ꢁNCHN),
8.71 (1H, s, OH), 7.72 (2H, AA’BB’, ArH), 7.18 (1H, d, J=8.6, ArH),
7.13 (1H, s, ArH), 6.74 (1H, d, J=2.2, ArH), 6.88–6.60 (3H, m, ArH),
4.04 (2H, t, J=7.7, CH2), 3.65 (3H, s, CH3), 2.82 ppm (2H, t, J=7.7,
CH2); 13C NMR (100 MHz, [D6]DMSO): d=151.4 (C), 151.1 (C), 144.1
(2ꢁCH), 134.4 (2ꢁCH), 131.8 (C), 128.6 (CH), 128.4 (C), 119.6 (C),
113.4 (2ꢁCH), 112.0 (CH), 110.7 (CH), 110.0 (C), 108.3 (C), 102.6
(CH), 54.1 (CH2), 32.9 (CH3), 22.6 ppm (CH2); MS (APCI): m/z (%):
359.2 (30) [M+H]+, 290.1 (100); HRMS-FAB: m/z [M]+ calcd for
C20H18N6O: 358.1542, found: 358.1556; HPLC (CH3CN/H2O, 70:30)
tR =1.81 min (purity: 97.9%).
Benzyl 2-[6-(benzyloxy)benzofuran-3-yl]acetate (58). 2-(6-Hydroxy-
benzofuran-3-yl)acetic acid[38,39] (1.65 g, 8.59 mmol) was added to a
cold (08C) suspension of NaH (60% in mineral oil, 0.76 g, 19 mmol)
in DMF (35 mL). The mixture was allowed to stir for 10 min at 08C,
and then benzyl bromide (3.23 g, 19 mmol) was added, and the re-
action was stirred overnight. The reaction mixture was poured
onto H2O (80 mL), and the product was extracted with EtOAc (2ꢁ
60 mL). The combined organic layers were washed with H2O (3ꢁ
80 mL) and brine (80 mL), then dried (MgSO4), and the solvent was
removed in vacuo. The crude product was purified using Flashmas-
ter II (EtOAc/Hexane) to give the title compound as a white solid
(2.90 g, 90%); mp: 77–78.58C; 1H NMR (400 MHz, CDCl3): d=7.53
(1H, s, ArH), 7.48–7.45 (2H, s, ArH), 7.42–7.32 (9H, m, ArH), 7.08
(1H, d, J=1.6, ArH), 6.95 (1H, dd, J=8.4, 2.0, ArH), 5.17 (2H, s,
CH2), 5.11 (2H, s, CH2), 3.72 ppm (2H, s, CH2); 13C NMR (100 MHz,
CDCl3): d=170.6 (C), 157.4 (C), 156.2 (C), 142.2 (CH), 137.0 (C),
135.8 (C), 128.8 (2ꢁCH), 128.8 (2ꢁCH), 128.6 (2ꢁCH), 128.5 (2ꢁ
CH), 128.2 (CH), 127.7 (CH), 121.4 (C), 120.1 (CH), 113.1 (C), 112.7
(CH), 97.6 (CH), 70.9 (CH2), 67.2 (CH2), 30.3 ppm (CH2); MS (APCI):
m/z (%): 371.2 (30) [MꢀH]ꢀ, 236.1 (30), 212.0 (100), 188.9 (20);
HRMS-FAB: m/z [M]+ calcd for C24H20O4: 372.1362, found: 372.1362.
3-{2-[(4-Cyanophenyl)(4H-1,2,4-triazol-4-yl)amino]ethyl}-1-
methyl-1H-indol-5-yl sulfamate (52). As per general method B
using H2NSO2Cl (0.7m, 1.4 mL), DMA (3.0 mL) and 51 (0.081 g,
0.23 mmol). The crude product was purified using Flashmaster II
(EtOAc/hexane/MeOH) to give the title compound as a white solid
(0.082 g, 83%); 1H NMR (270 MHz, [D6]DMSO): d=8.95 (2H, s, 2ꢁ
NCHN), 7.79 (2H, brs, NH2), 7.72 (2H, AA’BB’, ArH), 7.45 (1H, d, J=
8.9, ArH), 7.42 (1H, d, J=2.2, ArH), 7.35 (1H, s, ArH), 7.08 (1H, dd,
J=8.9, 2.2, ArH), 6.62 (2H, AA’BB’, ArH), 4.10 (2H, t, J=7.4, CH2),
3.75 (3H, s, CH3), 2.88 ppm (2H, t, J=7.4, CH2); 13C NMR (100 MHz,
[D6]DMSO): d=151.5 (C), 144.1 (2ꢁCH), 143.9 (C), 135.3 (C), 134.4
(2ꢁCH), 130.0 (CH), 127.6 (C), 119.6 (C), 116.7 (CH), 113.6 (2ꢁCH),
112.0 (CH), 110.9 (CH), 110.1 (C), 102.7 (C), 53.9 (CH2), 33.1 (CH3),
22.5 ppm (CH2); MS (APCI): m/z (%): 436.3 (100) [MꢀH]ꢀ; HRMS-
FAB: m/z [M+H]+ calcd for C20H20N7O3S: 438.1348, found:
438.1327; Anal. calcd for C20H19N7O3S: C 54.91, H 4.38, N 22.41,
found: C 54.90, H 4.60, N 22.00; HPLC (CH3CN/H2O, 90:10) tR =
1.75 min (purity: >99%).
2-[6-(Benzyloxy)benzofuran-3-yl]ethanol (59). A solution of 58
(0.21 g, 0.56 mmol) in THF (3 mL) was slowly added to a suspen-
sion of LiAlH4 (0.024 g, 0.60 mmol) in THF (6 mL). After stirring for
1 h, the reaction was quenched by the sequential addition of
EtOAc (10 mL), H2O (10 mL) and HCl(aq) (3m, 10 mL). The product
was extracted with EtOAc (3ꢁ10 mL), and the combined organic
layers were washed with brine (30 mL), dried (MgSO4), and the sol-
vent was removed in vacuo. The crude product was purified using
Flashmaster II (EtOAc/hexane) and then by recrystallisation EtOAc/
hexane to give the title compound as a white crystalline solid
(0.13 g, 86%); mp: 86.5–87.58C; 1H NMR (270 MHz, CDCl3): d=
7.50–7.28 (7H, m, ArH), 7.07 (1H, d, J=2.0, ArH), 6.96 (1H, dd, J=
8.6, 2.2, ArH), 5.10 (2H, s, CH2), 3.91 (2H, td, J=6.4, 5.9, CH2), 2.90
(2H, t, J=6.4, CH2), 1.61–1.50 ppm (1H, m, OH); 13C NMR (100 MHz,
CDCl3): d=157.5 (C), 156.2 (C), 142.5 (CH), 137.0 (C), 128.8 (2ꢁCH),
128.2 (CH), 127.7 (2ꢁCH), 121.8 (C), 119.9 (CH), 116.9 (C), 112.5
(CH), 97.7 (CH), 71.0 (CH2), 62.2 (CH2), 27.6 ppm (CH2); MS (ES): m/z
(%): 269.0 (25) [M+H]+, 250.9 (100), 192.8 (10), 175.7 (15), 162.6
(20), 140.6 (25), 123.6 (50); HRMS-FAB: m/z [M]+ calcd for C17H16O3:
268.1099, found: 268.1090; Anal. calcd for C24H22O5S: C 68.23, H
5.25, found: C 68.40, H 5.32.
4-({[5-(Benzyloxy)-1H-indol-3-yl]methyl}(4H-1,2,4-triazol-4-yl)ami-
no)benzonitrile (54). A suspension of 1-[5-(benzyloxy)-1H-indol-3-
yl]-N,N-dimethylmethanamine[36] (0.50 g, 1.79 mmol) and 53 (0.33 g,
1.79 mmol) in H2O/EtOH (1:1, 20 mL) was heated at reflux for 72 h
and then allowed to cool. The solvent was removed in vacuo, azeo-
troping with toluene to remove traces of H2O. EtOAc was added to
the residue, and the resulting white precipitate was collected by
filtration (unreacted starting material). The filtrate was purified
using Flashmaster II (EtOAc/hexane/MeOH) to give the title com-
pound as a white powder (0.19 g, 27%); mp: 185.5–1888C; 1H NMR
(270 MHz, [D6]DMSO): d=10.92 (1H, brs, NH), 8.46 (2H, s, 2ꢁ
NCHN), 7.78 (2H, AA’BB’, ArH), 7.47–7.21 (6H, m, ArH), 7.14 (1H, d,
J=2.5, ArH), 7.01 (1H, d, J=2.5, ArH), 6.87 (2H, AA’BB’, ArH), 6.80
(1H, dd, J=8.8, 2.5, ArH), 5.12 (2H, s, CH2Ar), 5.03 ppm (2H, s,
CH2Ar); 13C NMR (100 MHz, CDCl3): d=153.0 (C), 152.3 (C), 144.1
(2ꢁCH), 138.3 (C), 134.5 (2ꢁCH), 131.9 (2ꢁC), 129.0 (2ꢁCH), 128.3
(CH), 128.2 (2ꢁCH), 127.5 (CH), 119.8 (C), 114.6 (2ꢁCH), 113.1 (CH),
112.9 (CH), 107.3 (C), 103.2 (C), 102.2 (CH), 70.4 (CH2), 49.7 ppm
(CH2); MS (ES+): m/z (%): 421.2 (20) [M+H]+, 352.2 (100); HRMS-
FAB: m/z [M+H]+ calcd for C25H21N6O: 421.1777, found: 421.1775.
2-[6-(Benzyloxy)benzofuran-3-yl]ethyl
4-methylbenzenesulfo-
nate (60). p-Toluenesulfonyl chloride (0.32 g, 1.68 mmol) was
added to a cooled (08C) solution of 59 (0.30 g, 1.12 mmol) and pyr-
idine (0.18 g, 2.27 mmol) in CHCl3 (3 mL). After 1 h, the reaction
mixture was allowed to warm to room temperature and stirred
overnight. The solvent was removed in vacuo, and the residue was
purified using Flashmaster II (EtOAc/hexane) to give the title com-
pound as a white solid (0.39 g, 83%); mp: 83.5–858C; 1H NMR
(270 MHz, CDCl3): d=7.64 (2H, d, J=8.4, ArH), 7.49–7.28 (6H, m,
4-{[(5-Hydroxy-1H-indol-3-yl)methyl](4H-1,2,4-triazol-4-yl)amino}-
benzonitrile (55). As per general method A using 10% Pd/C
(15 mg), 54 (0.15 g, 0.36 mmol) and THF/MeOH (1:1, 40 mL). The
crude product was heated in a little iPrOH for 10 min, then collect-
ed by filtration washing with ether and hexane to give the title
ChemMedChem 2010, 5, 1577 – 1593
ꢀ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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1591

B. V. L. Potter et al.
MED
ArH), 7.26–7.17 (3H, m, ArH), 7.02 (1H, d, J=2.2, ArH), 6.90 (1H, dd,
J=8.6, 2.2, ArH), 5.09 (2H, s, CH2), 4.25 (2H, t, J=6.7, CH2OSO2),
2.98 (2H, t, J=6.7, CH2), 2.38 ppm (3H, s, CH3); 13C NMR (100 MHz,
CDCl3): d=157.3 (C), 156.7 (C), 144.9 (C), 141.7 (CH), 137.0 (C),
132.8 (C), 129.9 (2ꢁCH), 128.8 (2ꢁCH), 128.3 (CH), 128.0 (2ꢁCH),
127.7 (2ꢁCH), 121.2 (C), 119.6 (CH), 115.2 (C), 112.5 (CH), 97.6 (CH),
70.9 (CH2), 69.3 (CH2), 24.2 (CH2), 22.1 ppm (CH3); MS (ES): m/z (%):
423.1 (50) [M+H]+, 371.2 (10), 250.9 (100); HRMS-FAB: m/z [M+H]+
calcd for C24H22O5S: 422.1188, found: 422.1179.
120.7 (CH), 119.7 (C), 118.3 (CH), 116.8 (C), 113.9 (2ꢁCH), 106.7
(CH), 103.2 (C), 53.1 (CH2), 21.5 ppm (CH2); MS (ES): m/z (%): 425.4
(100) [M+H]+, 356.4 (40), 226.2 (100), 214.2 (30), 158.0 (80), 141.0
(50); HRMS-FAB: m/z [M]+ calcd for C19H17N6O4S: 425.1032, found:
425.1016; HPLC (CH3CN/H2O, 70:30) tR =2.61 min (purity: >99%).
6-(Benzyloxy)-2-methylbenzoxazole (65). 2-Methylbenzoxazol-6-ol
(3.60 g, 24.1 mmol) was added in small portions to a cooled (08C)
suspension of NaH (60% in mineral oil, 1.16 g, 29.0 mmol) in DMF
(50 mL). The resulting solution was allowed to warm to room tem-
perature and after 30 min, benzyl bromide (5.05 g, 29.5 mmol) was
added, and the reaction mixture was stirred overnight. The reac-
tion mixture was poured onto H2O (80 mL) and extracted with
EtOAc (2ꢁ40 mL). The combined organic layers were washed with
H2O (3ꢁ40 mL) and brine (40 mL), then dried (MgSO4), and the sol-
vent was removed in vacuo. The crude product was purified using
flash column chromatography (EtOAc/hexane, 1:6) to give the title
compound as a white solid (5.64 g, 98%); 1H NMR (270 MHz,
CDCl3): d=7.50 (1H, d, J=9.0, ArH), 7.48–7.30 (5H, m, ArH), 7.06
(1H, d, J=2.3, ArH) 6.98 (1H, dd, J=9.0, 2.3, ArH), 5.10 (2H, s, CH2),
2.60 ppm (3H, s, CH3); MS (ES): m/z (%): 237.8 (100) [MꢀH]ꢀ, 211.7
(75), 204.8 (50).
4-({2-[6-(Benzyloxy)benzofuran-3-yl]ethyl}(4H-1,2,4-triazol-4-yl)-
amino)benzonitrile (61). Compound 8 (0.10 g, 0.54 mmol) was
added in small portions to a cooled (08C) suspension of NaH (60%
in mineral oil, 0.028 g, 0.70 mmol) in DMF (5 mL). The resulting so-
lution was allowed to warm to room temperature, and after
30 min, 60 (0.25 g, 0.59 mmol) was added, and the reaction mix-
ture was stirred overnight. The resulting solution was poured onto
H2O (30 mL) and extracted with EtOAc (2ꢁ30 mL). The combined
organic layers were washed with H2O (3ꢁ30 mL) and brine
(30 mL), then dried (MgSO4), and solvent was removed in vacuo.
The crude product was purified using Flashmaster II (EtOAc/
hexane) to give the title compound as a white solid (0.15 g, 64%);
mp: 196.5–1988C; 1H NMR (400 MHz, [D6]DMSO): d=8.93 (2H, s,
2ꢁNCHN), 7.76 (1H, s, ArH), 7.69 (2H, AA’BB’, J=8.8, ArH), 7.51–
7.23 (7H, m, ArH), 6.94(1H, dd, J=8.4, 2.0, ArH), 6.61 (2H, AA’BB’,
J=8.0, ArH), 5.13 (2H, s, CH2), 4.14 (2H, t, J=8.0, CH2N), 2.85 ppm
(2H, t, J=8.0, NCH2CH2); 13C NMR (100 MHz, [D6]DMSO): d=157.3
(C), 156.1 (C), 151.6 (C), 144.2 (2ꢁCH), 142.6 (CH), 137.6 (C), 134.6
(2ꢁCH), 129.1 (2ꢁCH), 128.5 (CH), 128.4 (2ꢁCH), 121.5 (C), 120.5
(CH), 119.7 (C), 116.6 (C), 113.8 (2ꢁCH), 112.9 (CH), 103.1 (C), 98.0
(CH), 70.5 (CH2), 53.2 (CH2), 21.7 ppm (CH2); MS (ES): m/z (%): 436.2
(25) [M+H]+, 367.2 (100), 237.0 (45); HRMS-FAB: m/z [M+H]+ calcd
for C26H22N5O2: 436.1774, found: 436.1770.
6-(Benzyloxy)-2-(bromomethyl)benzoxazole (66). N-Bromosucci-
nimide (4.34 g, 24.1 mmol) and dibenzoylperoxide (90 mg) were
added to a stirred solution of 65 (5.50 g, 23.0 mmol) in CCl4
(100 mL). After heating at reflux for 2 h, the solution was filtered
and diluted with EtOAc. The filtrate was washed with aqueous 5%
NaOH and brine and then dried (Na2SO4), and the solvent was re-
moved in vacuo. Purification of the crude product by flash column
chromatography (hexane/EtOAc 7:1) gave the title compound as a
white solid (2.89 g, 39%); mp: 107–109.58C; 1H NMR (400 MHz,
CDCl3): d=7.58 (1H, d, J=8.6, ArH), 7.45–7.30 (5H, m, ArH), 7.09
(1H, d, J=2.3, ArH), 7.02 (1H, dd, J=8.6, 2.3, ArH), 5.09 (2H, s,
CH2), 4.53 ppm (2H, s, CH2); 13C NMR (68 MHz, [D6]DMSO): d=160.1
(C), 158.0 (C), 152.1 (C), 136.4 (C), 135.0 (C), 128.8 (2ꢁCH), 128.3
(CH), 127.6 (2ꢁCH), 120.7 (CH), 114.3 (CH), 96.7 (CH), 70.9 (CH2),
21.0 ppm (CH2); MS (FAB): m/z (%): 318.0 (48) [M+H]+, 239.0 (14),
91 (100); HRMS-FAB: m/z [M+H]+ calcd for C15H13NO2Br: 318.0130,
found: 318.0115.
4-{[2-(6-Hydroxybenzofuran-3-yl)ethyl](4H-1,2,4-triazol-4-yl)ami-
no}benzonitrile (62). As per general method A using 10% Pd/C
(80 mg), 61 (0.38 g, 0.87 mmol) and THF/MeOH (1:1, 50 mL). The
product was purified by trituration with hot EtOH, and the triturate
was purified by sequential recrystallisation from MeOH/EtOAc and
EtOAc/hexane. The title compound was obtained as an off-white
solid (0.26 g, 87%); mp: 246–247.58C; 1H NMR (400 MHz,
[D6]DMSO): d=9.55 (1H, brs, OH), 8.95 (2H, s, 2ꢁNCHN), 7.71 (2H,
AA’BB’, ArH), 7.70 (1H, s, ArH), 7.38 (1H, d, J=8.4, ArH), 6.88 (1H, d,
J=2.2, ArH), 6.74 (1H, dd, J=8.4, 2.2, ArH), 6.62 (2H, AA’BB’, ArH),
4.15 (2H, t, J=7.1, CH2N), 2.84 ppm (2H, t, J=7.1, NCH2CH2);
13C NMR (100 MHz, [D6]DMSO): d=156.4 (C), 156.3 (C), 151.6 (C),
144.2 (2ꢁCH), 141.7 (CH), 134.6 (2ꢁCH), 120.3 (CH), 120.1 (C), 119.7
(C), 116.6 (C), 113.8 (2ꢁCH), 112.6 (CH), 103.1 (C), 98.5 (CH), 53.3
(CH2), 21.7 ppm (CH2); MS (ES): m/z (%): 346.2 (10) [M+H]+, 277.0
(100), 146.7 (100); HRMS-FAB: m/z [M]+ calcd for C19H15N5O2:
345.1226, found: 345.1237; Anal. calcd for C19H15N5O2: C 66.08, H
4.38, N 20.28, found: C 65.70, H 4.56, N 20.20; HPLC (CH3CN/H2O,
70:30) tR =3.37 min (purity: >99%).
4-({[6-(Benzyloxy)benzoxazol-2-yl]methyl}(4H-1,2,4-triazol-4-yl)-
amino)benzonitrile (67). Compound 8 (0.055 g, 0.30 mmol) was
added in small portions to a cooled (08C) suspension of NaH (60%
in mineral oil, 0.012 g, 0.30 mmol) in DMF (10 mL). The resulting
solution was allowed to warm to room temperature, and after
30 min, 66 (0.10 g, 0.31 mmol) was added. After stirring overnight,
the reaction mixture was poured onto H2O (30 mL) and extracted
with EtOAc (2ꢁ30 mL). The combined organic layers were washed
with H2O (3ꢁ30 mL) and brine (30 mL), then dried (MgSO4), and
the solvent was removed in vacuo. The crude product was purified
using Flashmaster II (EtOAc/hexane) to give the title compound as
a white solid (0.080 g, 63%); 1H NMR (400 MHz, [D6]DMSO): d=
8.65 (2H, s, NCHN), 7.60–7.30 (8H, m, ArH), 7.15 (1H, d, J=2.2,
ArH), 7.02 (1H, dd, J=8.8, 2.2, ArH), 6.58 (2H, AA’BB’, ArH), 5.19
(2H, s, CH2), 5.11 ppm (2H, s, CH2); MS (ES): m/z (%): 421.0 (40)
[MꢀH]ꢀ, 330.0 (30), 211.7 (100), 183.7 (80); HRMS-ES: m/z [M+H]+
calcd for C24H19N6O2: 423.1564, found: 423.1567.
3-{2-[(4-Cyanophenyl)(4H-1,2,4-triazol-4-yl)amino]ethyl}benzo-
furan-6-yl sulfamate (63). As per general method B using
H2NSO2Cl (0.7m, 2.73 mL), DMA (3.5 mL) and 62 (0.16 g,
0.46 mmol). The crude product was purified by recrystallisation
from acetone/hexane to give the title compound as an off-white
1
solid (0.13 g, 66%); H NMR (270 MHz, [D6]DMSO): d=8.98 (2H, s,
4-{[(6-Hydroxybenzoxazol-2-yl)methyl](4H-1,2,4-triazol-4-yl)ami-
no}benzonitrile (68). As per general method A using 10% Pd/C
(65 mg), 67 (0.24 g, 5.56 mmol) and THF/MeOH (1:1, 60 mL). The
product was purified by trituration from hot EtOAc. The title com-
pound was obtained as an off-white solid (0.13 g, 69%); 1H NMR
(270 MHz, [D6]DMSO): d=9.86 (1H, s, OH), 8.95 (2H, s, NCHN), 7.74
2ꢁNCHN), 8.04–7.93 (3H, brs, H2N and ArH), 7.75–7.70 (3H, m,
ArH), 7.51 (1H, d, J=2.0, ArH), 7.23 (1H, dd, J=8.4, 2.0, ArH), 6.62
(2H, AA’BB’, ArH), 4.20 (2H, t, J=7.2, CH2N), 2.92 ppm (2H, t, J=
7.1, NCH2CH2); 13C NMR (100 MHz, [D6]DMSO): d=154.7 (C), 151.6
(C), 148.1 (C), 145.0 (CH), 144.2 (2ꢁCH), 134.6 (2ꢁCH), 126.5 (C),
1592
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ꢀ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemMedChem 2010, 5, 1577 – 1593

Bicyclic DASI Derivatives
[23] C. Bubert, L. W. L. Woo, O. B. Sutcliffe, M. F. Mahon, S. K. Chander, A. Pur-
ohit, M. J. Reed, B. V. L. Potter, ChemMedChem 2008, 3, 1708–1730.
[24] L. W. L. Woo, T. Jackson, A. Putey, G. Cozier, P. Leonard, K. R. Acharya,
S. K. Chander, A. Purohit, M. J. Reed, B. V. L. Potter, J. Med. Chem. 2010,
53, 2155–2170.
[25] T. Golob, R. Liebl, E. von Angerer, Bioorg. Med. Chem. 2002, 10, 3941–
3953.
[26] G. Walter, R. Liebl, E. von Angerer, J. Steroid Biochem. Mol. Biol. 2004, 88,
409–420.
(2H, AA’BB’, ArH), 7.48 (1H, d, J=8.6, ArH), 7.01 (1H, d, J=2.1,
ArH), 6.79 (1H, dd, J=8.6, 2.1, ArH), 6.69 (2H, AA’BB’, ArH),
5.47 ppm (2H, s, CH2); 13C NMR (100 MHz, [D6]DMSO): d=159.0 (C),
156.2 (C), 151.6 (C), 150.1 (C), 143.5 (2ꢁCH), 134.1 (2ꢁCH), 133.7
(C), 120.0 (CH), 119.0 (C), 113.3 (CH), 113.1 (2ꢁCH), 102.9 (C), 97.4
(CH), 50.4 ppm (CH2); MS (ES): m/z (%): 331.0 (10) [MꢀH]ꢀ, 261.8
(60), 183.7 (100); HRMS-FAB: m/z [M+Na]+ calcd for C17H12N6NaO2:
355.0914, found: 355.0904.
[27] E. P. Schreiner, B. Wolff, A. P. Winiski, A. Billich, Bioorg. Med. Chem. Lett.
2003, 13, 4313–4316.
Acknowledgements
[28] A. Billich, J. G. Meingassner, P. Nussbaumer, S. Desrayaud, C. Lam, A. Wi-
niski, E. Schreiner, J. Steroid Biochem. Mol. Biol. 2004, 92, 29–37.
[29] D. Ghosh, J. Griswold, M. Erman, W. Pangborn, Nature 2009, 457, 219–
223.
[30] F. G. Hernandez-Guzman, T. Higashiyama, W. Pangborn, Y. Osawa, D.
Ghosh, J. Biol. Chem. 2003, 278, 22989–22997.
[31] M. Okada, T. Yoden, E. Kawaminami, Y. Shimada, M. Kudoh, Y. Isomura,
H. Shikama, T. Fujikura, Chem. Pharm. Bull. 1996, 44, 1871–1879.
[32] M. Okada, S. Iwashita, N. Koizumi, Tetrahedron Lett. 2000, 41, 7047–
7051.
[33] S. M. Huh, J. I. Jin, Macromolecules 1997, 30, 3005–3013.
[34] K. N. F. Shaw, A. McMillan, A. G. Gudmundson, M. D. Armstrong, J. Org.
Chem. 1958, 23, 1171–1178.
[35] M. Lounasmaa, R. Jokela, L. P. Tiainen, Tetrahedron 1990, 46, 7873–7884.
[36] A. Ek, B. Witkop, J. Am. Chem. Soc. 1954, 76, 5579–5588.
[37] E. S. M. Afsah, A. H. Jackson, J. Chem. Soc. Perkin Trans. 1 1984, 1929–
1932.
[38] G. Zagotto, O. Gia, F. Baccichetti, E. Uriarte, M. Palumbo, Photochem.
Photobiol. 1993, 58, 486–491.
[39] Y. Fall, L. Santana, M. Teijeira, E. Uriarte, Heterocycles 1995, 41, 647–650.
[40] M. P. Lꢅzꢅ, M. Le Borgne, P. Pinson, A. Palusczak, M. Duflos, G. Le Baut,
R. W. Hartmann, Bioorg. Med. Chem. Lett. 2006, 16, 1134–1137.
[41] P. Marchand, M. Le Borgne, M. Palzer, G. Le Baut, R. W. Hartmann,
Bioorg. Med. Chem. Lett. 2003, 13, 1553–1555.
[42] M. Le Borgne, P. Marchand, B. Delevoye-Seiller, J. M. Robert, G. Le Baut,
R. W. Hartmann, M. Palzer, Bioorg. Med. Chem. Lett. 1999, 9, 333–336.
[43] M. P. Lꢅzꢅ, A. Palusczak, R. W. Hartmann, M. Le Borgne, Bioorg. Med.
Chem. Lett. 2008, 18, 4713–4715.
[44] F. Messina, M. Botta, F. Corelli, C. Mugnaini, Tetrahedron Lett. 1999, 40,
7289–7292.
[45] F. Messina, M. Botta, F. Corelli, A. Paladino, Tetrahedron: Asymmetry
2000, 11, 4895–4901.
[46] F. Messina, M. Botta, F. Corelli, M. P. Schneider, F. Fazio, J. Org. Chem.
1999, 64, 3767–3769.
[47] M. R. Saberi, T. K. Vinh, S. W. Yee, B. J. N. Griffiths, P. J. Evans, C. Simons,
J. Med. Chem. 2006, 49, 1016–1022.
[48] S. K. Chander, A. Purohit, L. W. L. Woo, B. V. L. Potter, M. J. Reed, Bio-
chem. Biophys. Res. Commun. 2004, 322, 217–222.
[49] M. Le Borgne, P. Marchand, M. Duflos, B. Delevoye-Seiller, S. Piessard-
Robert, G. Le Baut, R. W. Hartmann, M. Palzer, Arch. Pharm. 1997, 330,
141–145.
[50] G. Jones, P. Willett, R. C. Glen, A. R. Leach, R. Taylor, J. Mol. Biol. 1997,
267, 727–748.
[51] P. Furet, C. Batzl, A. Bhatnagar, E. Francotte, G. Rihs, M. Lang, J. Med.
Chem. 1993, 36, 1393–1400.
This work was funded by Sterix Ltd., which is a member of the
Ipsen Group. We thank Ms. A. C. Smith for technical assistance
and the EPSRC National Mass Spectrometry Service for some of
the high-resolution mass spectra.
Keywords: aromatase · breast cancer · dual inhibitors
endocrine therapy · sulfatase
·
[1] G. Beatson, Lancet 1896, 148, 104–107.
[2] A. Brodie, Trends Endocrinol. Metab. 2002, 13, 61–65.
[3] M. Recanatini, A. Cavalli, P. Valenti, Med. Res. Rev. 2002, 22, 282–304.
[4] R. W. Brueggemeier, J. C. Hackett, E. S. Diaz-Cruz, Endocr. Rev. 2005, 26,
331–345.
[5] J. M. Dixon, Expert Opin. Pharmacother. 2006, 7, 2465–2479.
[6] A. Howell, J. Cuzick, M. Baum, A. Buzdar, M. Dowsett, J. F. Forbes, G.
Hoctin-Boes, I. Houghton, G. Y. Locker, J. S. Tobias, Lancet 2005, 365,
60–62.
[7] The Breast International Group (BIG) 1-98 Collaborative Group, B. Thꢃrli-
mann, A. Keshaviah, A. S. Coates, H. Mouridsen, L. Mauriac, J. F. Forbes,
R. Paridaens, M. Castiglione-Gertsch, R. D. Gelber, M. Rabaglio, I. Smith,
A. Wardley, K. N. Price, A. Goldhirsch, N. Engl. J. Med. 2005, 353, 2747–
2757.
[8] N. M. Howarth, A. Purohit, M. J. Reed, B. V. L. Potter, J. Med. Chem. 1994,
37, 219–221.
[9] L. W. L. Woo, N. M. Howarth, A. Purohit, H. A. M. Hejaz, M. J. Reed,
B. V. L. Potter, J. Med. Chem. 1998, 41, 1068–1083.
[10] M. J. Reed, A. Purohit, L. W. L. Woo, S. P. Newman, B. V. L. Potter, Endocr.
Rev. 2004, 26, 171–202.
[11] L. W. L. Woo, A. Purohit, B. Malini, M. J. Reed, B. V. L. Potter, Chem. Biol.
2000, 7, 773–791.
[12] B. Malini, A. Purohit, D. Ganeshapillai, L. W. L. Woo, B. V. L. Potter, M. J.
Reed, J. Steroid Biochem. Mol. Biol. 2000, 75, 253–258.
[13] A. Purohit, L. W. L. Woo, B. V. L. Potter, M. J. Reed, Cancer Res. 2000, 60,
3394–3396.
[14] S. J. Stanway, A. Purohit, L. W. L. Woo, S. Sufi, D. Vigushin, R. Ward, R. H.
Wilson, F. Z. Stanczyk, N. Dobbs, E. Kulinskaya, M. Elliott, B. V. L. Potter,
M. J. Reed, R. C. Coombes, Clin. Cancer Res. 2006, 12, 1585–1592.
[15] R. Morphy, Z. Rankovic, J. Med. Chem. 2005, 48, 6523–6543.
[16] L. M. Espinoza-Fonseca, Bioorg. Med. Chem. 2006, 14, 896–897.
[17] B. Meunier, Acc. Chem. Res. 2008, 41, 69–77.
[18] L. W. L. Woo, O. B. Sutcliffe, C. Bubert, A. Grasso, S. K. Chander, A. Puro-
hit, M. J. Reed, B. V. L. Potter, J. Med. Chem. 2003, 46, 3193–3196.
[19] P. M. Wood, L. W. L. Woo, A. Humphreys, S. K. Chander, A. Purohit, M. J.
Reed, B. V. L. Potter, J. Steroid Biochem. Mol. Biol. 2005, 94, 123–130.
[20] L. W. L. Woo, C. Bubert, O. B. Sutcliffe, A. Smith, S. K. Chander, M. F.
Mahon, A. Purohit, M. J. Reed, B. V. L. Potter, J. Med. Chem. 2007, 50,
3540–3560.
[21] T. Jackson, L. W. L. Woo, M. N. Trusselle, S. K. Chander, A. Purohit, M. J.
Reed, B. V. L. Potter, Org. Biomol. Chem. 2007, 5, 2940–2952.
[22] P. M. Wood, L. W. L. Woo, J. R. Labrosse, M. N. Trusselle, S. Abbate, G.
Longhi, E. Castiglioni, F. Lebon, A. Purohit, M. J. Reed, B. V. L. Potter, J.
Med. Chem. 2008, 51, 4226–4238.
[52] SYBYL v. 7.3, Tripos Inc., 1699 South Hanley Road, St. Louis, MO, 63144
(USA).
[53] R. Appel, G. Berger, Chem. Ber. 1958, 91, 1339–1341.
[54] L. W. L. Woo, M. Lightowler, A. Purohit, M. J. Reed, B. V. L. Potter, J. Ste-
roid Biochem. Mol. Biol. 1996, 57, 79–88.
[55] M. Frigoli, C. Moustrou, A. Samat, R. Guglielmetti, Eur. J. Org. Chem.
2003, 2799–2812.
Received: May 10, 2010
Revised: June 9, 2010
Published online on July 14, 2010
ChemMedChem 2010, 5, 1577 – 1593
ꢀ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemmedchem.org
1593