Discovery of novel tricyclic compounds as squalene synthase inhibitors

Article abstract of DOI:10.1016/j.bmc.2012.02.054

In the present article, we have reported the design, synthesis, and identification of highly potent benzhydrol derivatives as squalene synthase inhibitors (compound 1). Unfortunately, the in vivo efficacies of the compounds were not enough for acquiring the clinical candidate. We continued our investigation to obtain a more in vivo efficacious template than the benzhydrol template. In our effort, we focused on a benzoxazepine ring and designed a new tricyclic scaffold by the incorporation of heterocycle into it. Prepared pyrrolobenzoxazepine derivatives showed further efficient in vitro and in vivo activities.

Full text of DOI:10.1016/j.bmc.2012.02.054

Bioorganic & Medicinal Chemistry 20 (2012) 3072–3093
Contents lists available at SciVerse ScienceDirect
Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com/locate/bmc
Discovery of novel tricyclic compounds as squalene synthase inhibitors
Masanori Ichikawa a, , Masami Ohtsuka b, Hitoshi Ohki b, Noriyasu Haginoya b, Masao Itoh b,
⇑
Kazuyuki Sugita f, Hiroyuki Usui b, Makoto Suzuki c, Koji Terayama d, Akira Kanda e
a Lead Discovery and Optimization Research Laboratories I, R&D Division, Daiichi Sankyo Co. Ltd, 1-2-58 Hiromachi, Shinagawa-ku, Tokyo 140-8710, Japan
b Lead Discovery and Optimization Research Laboratories II, R&D Division, Daiichi Sankyo Co. Ltd, 1-2-58 Hiromachi, Shinagawa-ku, Tokyo 140-8710, Japan
c R&D Planning Department, R&D Division, Daiichi Sankyo Co. Ltd, 1-2-58 Hiromachi, Shinagawa-ku, Tokyo 140-8710, Japan
d Cardiovascular-Metabolics Research Laboratories, R&D Division, Daiichi Sankyo Co. Ltd, 1-2-58 Hiromachi, Shinagawa-ku, Tokyo 140-8710, Japan
e Biological Research Laboratories, R&D Division, Daiichi Sankyo Co. Ltd, 1-2-58 Hiromachi, Shinagawa-ku, Tokyo 140-8710, Japan
f Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
In the present article, we have reported the design, synthesis, and identification of highly potent benzhy-
drol derivatives as squalene synthase inhibitors (compound 1). Unfortunately, the in vivo efficacies of the
compounds were not enough for acquiring the clinical candidate. We continued our investigation to
obtain a more in vivo efficacious template than the benzhydrol template.
In our effort, we focused on a benzoxazepine ring and designed a new tricyclic scaffold by the incorpo-
ration of heterocycle into it. Prepared pyrrolobenzoxazepine derivatives showed further efficient in vitro
and in vivo activities.
Received 18 January 2012
Revised 22 February 2012
Accepted 23 February 2012
Available online 8 March 2012
Keywords:
Hypercholesterolemia
Squalene synthase inhibitor
Pyrrolobenzoxazepine
Lipid-lowering effect
Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction
Medicinal chemistry efforts to identify small and efficient squa-
lene synthase inhibitors have been reported by some research
The western dietary pattern has increased hyperlipidemia
around the world. The high level serum low density lipoprotein
(LDL) cholesterol is one of the risk factors associated with coronary
heart disease (CHD). 3-Hydroxy-3-methylglutaryl coenzyme A
(HMG-CoA) reductase inhibitors, statins, were regarded as the first
line medicine for the patients who have higher serum level of LDL
cholesterol.
Statins’ CHD risk reducing abilities, owing to their LDL choles-
terol lowering effects, were proofed by many clinical trials.1 How-
ever, statins have potential adverse effects, such as myotoxicity,
muscle pain and, in very rare case, rhabdomyolysis.2 Because of
the inhibition of HMG-CoA reductase also interferes with the syn-
thesis of many biologically essential non-steroidal isoprenoid mol-
ecules. Cerivastatin, one of the strongest statin, was withdrawn
from the world market in 2001, due to its adverse effect.3
In the cholesterol biosynthesis cascade, squalene synthase is lo-
cated in the downstream of HMG-CoA reductase and the first step
of the steroids synthesis.4 This means the inhibitor of the enzyme
prevents cholesterol biosynthesis without interrupting isoprenoids
production.5 In other words, the squalene synthase inhibitor has a
chance of avoiding the statin’s adverse effects.
groups.6
We have already reported an original 2-aminobenzhydrol tem-
plate for highly potent squalene synthase inhibitors.7 Interestingly,
these compounds formed 11-membered ring active conformations
with intramolecular hydrogen bonds between its benzhydrol hy-
droxyl part and side chain amide carbonyl oxygen in the squalene
synthase catalytic domain. Moreover, we have recently disclosed
the fixation of active conformation without loss of the activities
by using alkoxy-aminobenzhydrol template.8 These compounds
showed in vitro strong inhibitory activities, their IC50 values reach-
ing nanomolar order and the derivatives demonstrated plasma li-
pid-lowering effects in repeated dose studies in animal models.
Unfortunately, the in vivo efficacies of these compounds were
not enough for acquiring the clinical candidate in spite of their
strong in vitro activities. We needed to obtain a more in vivo effi-
cacious template than the benzhydrol derivatives.
We anticipated the reasons why these compounds were insuffi-
cient in vivo. One, the intramolecular hydrogen bond was probably
inadequate to keep the active conformation. Another, their meta-
bolic and chemical instabilities were likely to cause their insuffi-
cient concentrations of compounds in target organ (liver).
To obtain a more effective template in the biological condition,
we focused on the benzoxazepine ring structure, because ether
bond was more stable than the intramolecular hydrogen bond of
the benzhydrol part.9 Furthermore, we designed a new tricyclic
⇑
Corresponding author. Tel.: +81 3 3492 3131.
E-mail address: ichikawa.masanori.uf@daiichisankyo.co.jp (M. Ichikawa).
0968-0896/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.bmc.2012.02.054

M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
3073
O
O
O
Recent approach
New approach
O
OH
O
O
O
O
O
O
O
O
Cl
N
Cl
O
OH
OH
Cl
O
R
Cl
O
OH
N
N
X
N
O
O
O
Compound 1
Takeda's comp.
Figure 1.
New tricyclic comp.
scaffold which incorporated one more heteroaryl ring within the
benzoxazepine bicyclic template, instead of the bulky neopentyl
amide part, to aim at fixing the template more rigid and improving
the in vivo stability. Initially, we synthesized five membered pyr-
role ring incorporated tricyclic compounds, as shown in Figure 1.
In this article, we will describe our investigation of the discov-
ery of further in vivo efficacious novel tricyclic compounds, as well
as their structure–activity relationship (SAR) as squalene synthase
inhibitors, and in vivo lipid lowering effects in animal models.
Heteroaryl substituted compounds were prepared from meth-
ansulfonate 26 as shown in Scheme 3. Azide intermediate 31 was
obtained from 26 using sodium azide, and the following cyclization
with various alkynes obtained 1,2,3-triazole derivatives 32a–f.
Other heteroaryl derivatives 34a–k were prepared by direct substi-
tutions of 26 with pyrazole or tetrazole rings. Hydrolysis of the es-
ters gave final acids 33a–f and 35a–k, successively.
2.2. Evaluation and discussion
In order to obtain the structure–activity relationship (SAR),
prepared derivatives were evaluated in terms of their squalene
synthase inhibitory (SSI) activities and cholesterol synthesis inhib-
itory (CSI) activities in rat hepatic cells.10 Cell-base CSI activity was
used as a potential parameter to predict in vivo CSI activity, and
was considered more important than SSI activity as a guide to af-
ford effective cholesterol lowering medicine. Because CSI activity
is including cell permeability and cell surface transporter recogni-
tion of evaluated compound. At the next stage, compounds were
evaluated in an acute in vivo model; hepatic cholesterol synthesis
inhibitory (in vivo CSI) activities were measured in rat 3 mg/kg sin-
gle oral administration. The reduction of cholesterol in hepatic cell
causes an expression of LDL receptor on the surface of the hepatic
cell, via SREBP1 activation. As a consequence of an influx of LDL
lipoprotein to hepatic cell, serum lipid levels are decreased.11
Therefore, selected effective compounds were going to evaluate
in final chronic model, serum lipid lowering test in marmoset
100 mg/kg/day orally repeated dose for 7 days.
As summarized in Table 1, firstly prepared pyrrolobenzoxaze-
pine racemic compounds showed highly potent SSI activities. The
acetic acid 8 and 4-piperidinyl acetic acid 10 showed low nanomo-
lar order IC50 value (3.3 nM for 8, 2.7 nM for 10, respectively). The
validity of our new designed template was proved by these data.
The new tricyclic template would fix the direction of the upper ring
part to appropriate positions in squalene synthase, like intramolec-
ular hydrogen bonded 2-aminobenzhydrol derivatives, as expected.
Moreover, two 1-substituted pyrrolobenzoxazepine derivatives,
one being 1-chloro compound 11, another being 1-morpholinylm-
ethyl compound 12, also showed high SSI potentials. It could be
said that we had found a way to adjust physiological properties
of the new template without loss of the potency. Furthermore,
Table 1 suggested that the amide type side chain probably be supe-
rior to acetic acid side chain in terms of CSI activity. After that we
focused on the amide side chain optimization.
2. Result
2.1. Chemistry
A series of the novel pyrrolobenzoxazepine derivatives were
prepared from 2-aminobenzophenone via Michael reaction of
b-unsaturated ester as shown in Scheme 1. Commercially available
2-aminobenzophenone 2 was treated by 2,4-dimethoxytetrahy-
drofuran and acetic acid to have a pyrrole compound 3, followed
by the Vilsmeier reaction to obtain aldehyde 4 in good yield. a,b-
Unsaturated ester 5 was prepared by Wittig reagent from the
aldehyde.
In our synthetic strategy to prepare the pyrrolobenzoxazepine
template, seven membered oxazepine ring cyclization was the
key step. First, we tried the basic condition to cyclize a,b-unsatu-
rated ester attached benzhydrol intermediate 6. However, the
cyclization did not proceed. Second, we chose acidic conditions,
by using excess amounts of formic acid or trifluoroacetic acid,
and only a trace amount of cyclized compound was detected. Final-
ly, we optimized the reaction condition by reducing the volume of
trifluoroacetic acid, and obtained a cyclized pyrrolobenzoxazepine
template 7, containing small amount of cis isomer, from a,b-unsat-
urated methyl ester intermediate 6. The following side chain con-
version gave the ester and acid compounds 8–10.
Then, we prepared 2-substituted pyrrole derivatives 11–13
from the tricyclic template, using N-chloro succinamide or the
Mannich reaction with amines and formalin.
The upper aryl ring changed compounds were prepared from
2-bromoaniline 16 or N-Boc aniline 20 as outlined in Scheme 1.
Pyrrole ring cyclization and coupling with aldehydes gave ben-
zhydrols 17A,B. Subsequent manganese oxidation of 17A,B affor-
ded benzophenones 18A,B. From N-Boc aniline 20, rtho lithiation
and aldehyde coupling gave benzhydrol 21, following manganese
oxidation, acidic deprotection, and pyrrole cyclization afforded
18C. Subsequent sequential steps, formilation, Wittig reaction,
NaBH4 reduction, and optimized acidic condition cyclization gave
tricyclic ester intermediates. A series of acid derivatives 19A–C
were also prepared from these esters in a similar manner.
Chiral pyrrolobenzoxazepine ester compounds, (4R,6S)-14a and
(4S,6R)-14a, were separated and purified by HPLC with the chiral
column.
a,
To have SAR about the upper aryl ring part, we then tried to pre-
pare and evaluate 2,3-dimethoxyphenyl ring replaced compounds,
such as 1-naphtyl, 2,3-dichlorophenyl, and 1,4-benzdioxane-8-yl
derivatives (19A–C). As a result, these compounds showed weaker
SSI activities compared with 8 (Table 2), despite 1,4-benzdioxane-
8-yl part showed one of the highest potency on the 2-aminobenz-
hydrol template.7 Obviously, another SAR was obtained from our
new template. We hypothesized that more rigid tricyclic template
was recognized more strictly by the squalene synthase active cite.
At the next stage, we prepared chiral tricyclic compounds using
the HPLC with chiral column, and prepared varied amide side chain
compounds. The compounds and data were listed in Table 3. Only
Side chain extended compounds were prepared from compound
7. LiAlH4 reduction of separated chiral ester 24, following
methanesulfonylation, cyano conversion, and hydrolysis gave ex-
tended acid. Amide derivatives were prepared same as the shorter
amides (Scheme 2).

3074
M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
O
O
O
O
O
O
O
O
e
O
a
c
b
X
N
Cl
Cl
Cl
O
O
O
Cl
O
R
N
N
O
N
R
R = H
R = OMe
R = OH
7
8
2
3
4
5
6
X = CO
X = CHOH
f
d
R = CHO
g
f
CO2Et
CO2H
R =
R =
N
9
10
N
O
O
h, f
or
O
O
j
i, f
Cl
Cl
O
O
CO2R
9
7
N
O
O
N
N
O
R
R = Cl
14a-g R = Me or Et
15a-g R = H
11
12
R =
N
R =
13
N
O
Ar
Ar
Ar
Cl
Cl
O
O
Cl
Cl
Br
O
b, c, d, e, f
k
l
O
N
N
N
N
O
or
16
17A-B
18A-C
b, m, d, e, n
19A-C
a
Cl
O
O
O
Cl
O
Ar =
Cl
O
O
l
k
A
B
C
Cl
Cl
O
O
NH
Boc
R
Boc
N
H
N
H
20
21
22
23
R = Boc
R = H
c
Scheme 1. General synthetic procedure. Reagents and conditions: (a) 2,5-dimethoxytetrahydrofuran, AcOH, reflux, 1 h; (b) POCl3, DMF, DCE, 50 °C, 3 h; (c) methyl
(triphenylphosphoranylidene)acetate, toluene, 100 °C, 7 h; (d) NaBH4, MeOH, rt, 1 h; (e) 1.5 equiv TFA, DCM, rt, 8 h; (f) K2CO3, MeOH–H2O, rt; (g) amine, EDC, HOBt, DCM, rt;
(h) NCS, THF, rt; (i) HCHO, amine, AcOH, rt; (j) HPLC separation by using CHIRALCEL OD (2-PrOH–Hexane); (k) nBuLi, THF, À78 °C then aldehyde; (l) MnO2, DCM, 50 °C; (m)
benzyl (triphenylphosphoranylidene)acetate; (n) H2, Pd-C, MeOH.
O
O
O
O
O
O
O
N
a
b
f
Cl
O
Cl
Cl
O
O
R
7
O
N
N
N
R
O
29a-i R = CO2R'
30a-i R = CO2H
25 R = OH
26 R = OMs
27 R = CN
24
g
c
d
e
28 R = CO2H
Scheme 2. Side chain extension. Reagents and conditions: (a) HPLC separation by using CHIRALCEL OD (2-PrOH–Hexane); (b) LiAlH4, THF, 0 °C, 3 h; (c) MsCl, EtN3, 0 °C, 3 h;
(d) NaCN, DMSO, 50 °C, 13 h; (e) NaOH, 2-PrOH–H2O, reflux; (f) amine, EDC, HOBt, DCM, rt; (g) K2CO3, MeOH–H2O, rt.
(4R,6S)-isomers showed SSI activities, and many highly potent
compounds were obtained, even though their CSI activities were
insufficient.
and Asn 215 observed in the published X-ray crystal structure
(PDB ID: 1EZF)14 and they designed an oxazolobenzoxazepine tem-
plate to retain this hydrogen bond by replacing the amide carbonyl
group to the oxazole ring. However, our original pyrrolobenzoxaze-
pine template revealed that the hydrogen bond poorly contributed
to the inhibitory activity, because our compounds demonstrated
highly potent inhibitory activities without such a hydrogen bond.
In other words, lipophilic interaction between the rigid scaffold
and the lipophilic pocket of the enzyme caused such strong SSI
activities.
To elucidate the binding mode of our tricyclic template, we
investigated the X-ray structure analysis of squalene synthase co-
crystallized with compound (4R,6S)-15a (Fig. 2).12 The tricyclic
template with the upper ring part was deeply buried in the lipo-
philic pocket of the squalene synthase active site. There was no
hydrogen bond interaction around the pyrrolobenzoxazepine tem-
plate. Independently, Bayer’s research team has reported a tricyclic
template for squalene synthase inhibitors.13 In the report, they fo-
cused on the water mediated hydrogen bond between the amide
carbonyl group of the squalene synthase inhibitor (CP-320473)
According to our X-ray structure analysis, the piperidine amide
side chain is bending along with the slit to the active site of squa-
lene synthase, and forming two hydrogen bonds with squalene

M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
3075
O
Table 3
O
Evaluation of SSI and CSI activities of various chiral compounds
O
O
N
O
O
N
a
d
b
Cl
Cl
O
N
O
N3
26
26
R
N
N
Cl
O
32a-f R = CO2R'
33a-f R = CO2H
31
c
R
N
O
O
O
R
R
SSI (IC50, nM)
>600
CSI (IC50, nM)
Cl
O
N
CO2H
CO2H
N
(4S,6R)-15a
—
N
34a-k R = CO2R'
35a-k R = CO2H
c
(4R,6S)-15a
N
N
1.3
3.4
49
CO2H
CO2H
15b
170
Scheme 3. Synthesis of heteroaryl substituted compounds. Reagents and condi-
tions: (a) NaN3, DMF, 40 °C, 6 h; (b) alkyn, toluene, reflux; (c) K2CO3, MeOH–H2O, rt;
(d) heteroaryl ester, NaH, DMF, then 28, 0 °C.
15c
2.3
60
N
N
CO2H
15d
15e
15f
4.3
2.3
2.9
150
94
N
Table 1
H
N
Evaluation of squalene synthase inhibitory (SSI) activities and cholesterol synthesis
inhibitory (CSI) activities of racemic compounds
CO2H
CO2H
H
N
O
O
160
H
N
Cl
O
15g
4.0
150
CO2H
R1
N
O
R2
SSI: Squalene Synthase Inhibitory activity. CSI: Cholestrol Synthesis Inhibitory
activity in rat hepatic cell. ‘—, not tested’.
R1
R2
SSI
CSI
(IC50, nM)
(IC50, nM)
7
8
OMe
OH
H
H
220
3.3
—
250
CO2H
10
11
12
H
2.7
1.6
540
63
560
—
N
OH
Cl
N
OH
OH
N
13
O
7.6
160
SSI: Squalene Synthase Inhibitory activity. CSI: Cholestrol Synthesis Inhibitory
activity in rat hepatic cell. ‘—, not tested’.
Table 2
Evaluation of SSI and CSI activities of various upper aryl ring compounds
Ar
Cl
O
OH
N
O
Figure 2. Crystal structure of compound (4R,6S)-15a bound in squalene synthase
active site (PDB code: 3V66).12
Ar
SSI (IC50, nM)
3.3
O
8
O
synthase, one is between the amide carbonyl group and Tyr73 via
water, and another is between the carboxylic acid group and Ser53.
We considered that the amide side chain was the most permis-
sive part for structure conversion, due to its location; it was in the
edge of the active site and facing to the solvent side, and the water
mediated hydrogen bond of the amide group could be optimized.
To find a more efficacious inhibitor, we focused our SAR studies
on this side chain part.
In consequence, we found that some side chain extended com-
pounds were successively improved on their CSI activities. These
extended compounds showed stronger SSI and CSI activities than
the shorter side chain compounds (Table 4). 4-(Piperidinyloxy)ace-
tic acid 30e and 2-morpholine carboxylic acid 30h showed very
19A
19B
>600
52
Cl
O
Cl
O
19C
440
SSI: Squalene Synthase Inhibitory activity.

3076
M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
Table 4
Table 5
Evaluation of SSI, CSI and in vivo hepatic cholesterol synthesis inhibitory activities of
side chain extended compounds
Evaluation of SSI, CSI and in vivo hepatic cholesterol synthesis inhibitory activities of
heteroaryl substituted compounds
O
O
O
O
O
Cl
Cl
O
O
R
R
N
N
R
SSI
(IC50, nM)
CSI
(IC50, nM)
Rat in vivo CSI
(3 mg/kg, po, %)
R
SSI
(IC50, nM)
CSI
(IC50, nM)
Rat in vivo CSI
(3 mg/kg, po, %)
28
OH
3.1
>1000
93
—
N
N
N
N
CO2H
CO2H
33a
33b
0.59
25
24
44
66
30a
2.4
1.4
35
CO2H
N
N
N
0.51
0.81
30b
70
53
CO2H
N
N
N
N
CO2H
CO2H
30c
30d
2.2
7.0
23
36
31
41
N
33c
41
50
HO2C
N
N
N
N
CO2H
N
N
30e
30f
0.8
1.4
7.2
35
18
23
O
O
33d
33e
0.68
0.69
19
18
36
O
CO2H
CO2H
CO2H
CO2H
N
N
N
N
N
N
7.3
O
O
N
N
30g
30h
30i
0.9
1.6
2.2
10
9.7
11
7
N
33f
1.7
1.3
14
58
45
64
O
CO2H
CO2H
O
13
1
N
N
CO2H
35a
O
N
CO2H
N
N
35b
1.6
210
5
HO2C
SSI: Squalene Synthase Inhibitory activity. CSI: Cholestrol Synthesis Inhibitory
activity in rat hepatic cell. Rat in vivo CSI: hepatic cholestrol synthesis inhibition (%)
in rat at 1 h after 3 mg/kg single dose oral administration (n = 4–6). ‘—, not tested’.
N
N
35c
35d
35e
35f
2.1
54
62
18
36
56
34
38
86
CO2H
N
N
strong CSI activities, the IC50 values were 7.2 and 9.7 nM,
respectively.
3.1
CO2H
Some of these extended amide compounds showed efficacious
in vivo hepatic cholesterol synthesis inhibitory (in vivo CSI) activ-
ities. Especially, compound 30b showed 53% inhibition. Neverthe-
less, we estimated that more efficacious in vivo CSI activity was
required for serum lipid reduction in a repeated dose test.
We supposed that the inhibitor’s hepatic concentration was
important for in vivo CSI activity. There were a few reasons for this.
First, squalene synthase is expressed in the liver, main metabolic
organ in animal. Second, our inhibitors with amide bond are
metabolized to acid derivatives. Third, CSI activities of the acid
metabolites may drop, as shown in Table 1. We next turned our
attention to replace amide part to more metabolic stable hetero-
aryl ring, such as 1,2,3-triazole, pyrazole, and tetrazole rings.
Surprisingly, prepared amide changed heteroaryl compounds
showed improved SSI and CSI potencies than amide compounds.
The results appear in Table 5. In our speculation, these incorpo-
rated heteroaryl rings would directly interact with Tyr 73. As a re-
sult, in vitro activities were improved. Especially, compound 33b
and 35a, f, h further progressed in in vivo CSI activities (the values
of % reduction were 66%, 64%, 86%, and 64%, respectively).
Finally, we investigated in marmoset serum lipid lowering test
with selected compounds (4R,6S)-15a, 30b, 33b, 35a, f and Take-
da’s phase III entered TAK-475,15 as positive control, at 100 mg/
kg/day repeated oral administrations for 7 days (Table 6). In this
study, non-HDL cholesterol reduction was more important than to-
tal cholesterol (TC) reduction, which including HDL cholesterol
reduction. Triglyceride (TG) reduction was also significant for an
anti-hyperlipidemic reagent.
N
N
N
N
0.89
1.1
N
CO2H
N
N
CO2H
N
N
N
N
N
35g
1.1
130
—
HO2C
N
N
N
N
35h
35i
35j
0.85
1.1
70
58
52
64
44
53
N
CO2H
N
N
CO2H
N
N
N
N
N
1.7
CO2H
O
N
N
N
35k
2.5
10
51
N
CO2H
SSI: Squalene Synthase Inhibitory activity. CSI: Cholestrol Synthesis Inhibitory
activity in rat hepatic cell. Rat in vivo CSI: hepatic cholestrol synthesis inhibition (%)
in rat at 1 h after 3 mg/kg single dose oral administration (n = 4–6). ‘—, not tested’.
Consequently, compound 30b, 33b, 35a demonstrated statisti-
cally significant reduction of serum non-HDL cholesterol levels,
from 21% to 52% reduction compared with pre-values, especially

M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
3077
Table 6
spectra were recorded on JEOL JNM-EX400 spectrometers, and
chemical shifts are given in ppm from tetramethylsilane as an
internal standard. Parenthetical peak derives from minor atrop-
isomer. FAB mass spectra were recorded on a JEOL JMS-HX110
spectrometer. HR-FAB mass spectra were recorded on a JEOL
JMS-700. ESI mass spectra were recorded on SCIEX API-150EX
and Agilent Technologies Agilent 1100 series LC/MS. Column chro-
matography was performed with Merck silica gel 60 (particle size
0.060–0.200 or 0.040–0.063). Flash column chromatography was
performed with YAMAZEN cartridge series or ultra pack series.
Thin-layer chromatography (TLC) was performed on Merck pre-
coated TLC glass sheets with silica gel 60F254 or Whatman Partisil
PLK5F with Silica gel 150 Å.
Evaluation of serum lipid lowering effects of selected compounds in marmoset
100 mg/kg/day orally repeated doses for 7 days
O
O
Cl
O
R
N
R
TC
(%)
HDL-Cho
(%)
non-HDL-
Cho (%)
TG
(%)
TAK-475
23
14
29
25
CO2H
CO2H
(4R,6S)-
15a
28**
N
4
À11
9
O
4.1.1.1. [5-Chloro-2-(1H-pyrrol-1-yl)phenyl](2,3-dimethoxy-
phenyl)methanone (3).
(2-Amino-5-chlorophenyl)(2,3-dime
30b
9*
À21
23**
21
N
thoxyphenyl)methanone 2 (2.91 g, 9.97 mmol) was dissolved in
acetic acid (60 ml). To the resulting solution was added 2,5-dime-
thoxytetrahydrofuran (2.07 ml, 15.96 mmol) and the resulting
mixture was heated under reflux for 30 min. After cooling the reac-
tion mixture to room temperature, it was concentrated. The con-
centrate was diluted with ethyl acetate, and washed with satd
NaHCO3 aq and brine. The organic layer was dried over Na2SO4,
and then concentrated in vacuo. The residue was purified by silica
gel column chromatography (ethyl acetate–hexane = 1:20) to give
the title compound 3 (1.80 g, 5.27 mmol, 55%). MS(ESI) m/z 342
(M+H)+. 1H NMR (CDCl3) d 3.52 (3H, s), 3.83 (3H, s), 6.06 (2H, t,
J = 2.2 Hz), 6.73 (2H, t, J = 2.2 Hz), 6.97 (2H, d, J = 5.1 Hz), 7.02–
7.03 (1H, m), 7.30–7.32 (1H, m), 7.48–7.51 (2H, m).
O
N
N
N
10*
À8
À10
6
21**
52**
21
24
16
12
N
33b
35a
35f
CO2H
CO2H
N
27**
14
N
N
N
CO2H
N
TC: Total Cholestrol (% reduction compared with pre-value). HDL-Cho: HDL Cho-
lestrol. non-HDL-Cho: non-HDL Cholestrol. TG: Triglyceride. n = 6–8 (TAK-475,
n = 41).
*
P <0.05.
P <0.05 versus vehicle.
**
4.1.1.2. 1-[4-Chloro-2-(2,3-dimethoxybenzoyl)phenyl]-1H-pyr-
35a showed highest 52% reduction. Moreover, compound (4R,6S)-
15a, 30b, 33b showed highly triglyceride reducing potencies (28%,
21%, and 41%, respectively). Furthermore, all our compounds ex-
cept for 35f slightly increased HDL cholesterol levels, up to 21% in-
crease. Those data indicated that we have found quite efficacious
anti-hyperlipidemic reagents, superior to the original aminobenz-
hydrol derivatives.16
role-2-carbaldehyde (4).
To N,N-dimethylformamide (1.71
ml, 22.12 mmol) was added phosphorus oxychloride (1.62 ml,
17.38 mmol) under ice-cooling, and the resulting mixture was stir-
red at room temperature for 10 min. A solution of compound 3
(1.80 g, 5.27 mmol) in dichloroethane (40 ml) was added dropwise
to the reaction mixture. After warming to 50 °C, the reaction mix-
ture was stirred under heat for 2 h. An aqueous solution (40 ml) of
sodium acetate trihydrate (3.94 g, 29.0 mmol) was added to the
reaction mixture, followed by heating under reflux for 30 min.
After cooling to room temperature, the reaction mixture was di-
luted with chloroform and washed with brine. The organic layer
was dried over Na2SO4, and then concentrated in vacuo. The resi-
due was purified by silica gel column chromatography (ethyl ace-
tate–hexane = 1:8) to give the title compound 4 (1.19 g, 3.22 mmol,
61%) and 3-aldehyde isomer (0.52 g, 1.41 mmol, 27%). MS (ESI) m/z
370 (M+H)+. 1H NMR (CDCl3) d 3.62 (3H, s), 3.83 (3H, s), 6.19 (1H,
dd, J = 3.9, 2.4 Hz), 6.84–6.91 (2H, m), 6.92–6.97 (3H, m), 7.29 (1H,
d, J = 8.3 Hz), 7.53 (1H, dd, J = 8.3, 2.4 Hz), 7.59 (1H, d, J = 2.4 Hz),
9.39 (1H, s).
3. Conclusion
In order to obtain more in vivo efficient inhibitors, we focused
on a benzoxazepin ring and designed a new tricyclic scaffold by
the incorporation of heterocycle within. A new series of squalene
synthase inhibitors based on the pyrrolobenzoxazepine template
has been identified. Many of the derivatives of this series exhibited
good squalene synthase inhibitory (SSI) potencies. Through side
chain optimization, some extended amide derivatives showed im-
proved cholesterol synthesis inhibitory (CSI) potency in rat hepatic
cell.
Additionally, we succeeded in improving in vivo efficacy in rat
single dose hepatic cholesterol synthesis inhibitory studies by
replacing the side chain amide groups to the heteroaryl rings. Con-
sequently, highly potent squalene synthase inhibitors were ob-
tained. Furthermore, our novel compounds, especially 35a, have
demonstrated excellent serum lipid ameliorating efficacies in the
marmoset oral repeated doses study.
4.1.1.3. Methyl (E)-3-{1-[4-chloro-2-(2,3-dimethoxybenzoyl)
phenyl]-1H-pyrrol-2-yl}-2- propenoate (5).
Compound 4
(1.19 g, 3.22 mmol) was dissolved in toluene (20 ml). To the result-
ing solution, methoxycarbonylmethylene triphenylphosphorane
(2.15 g, 6.44 mmol) was added and the mixture was heated and
stirred overnight at 100 °C. The reaction mixture was cooled to
room temperature and then concentrated in vacuo. The residue
was purified by silica gel column chromatography (ethyl acetate–
hexane = 1:9) to give the title compound 5 (1.20 g, 2.82 mmol,
88%). 1H NMR (CDCl3) d 3.55 (3H, s), 3.72 (3H, s), 3.80 (3H, s),
5.92 (1H, d, J = 15.9 Hz), 6.07–6.10 (1H, m), 6.49–6.52 (1H, m),
6.78–6.80 (1H, m), 6.89–6.85 (1H, m), 6.92–6.94 (2H, m), 7.19
(1H, d, J = 15.9 Hz), 7.24 (1H, d, J = 8.3 Hz), 7.55 (1H, dd, J = 8.3,
2.4 Hz), 7.60 (1H, d, J = 2.4 Hz).
4. Experimental
4.1. Chemistry
4.1.1. General
Unless otherwise noted, materials were obtained from commer-
cial suppliers and used without further purification. 1H NMR

3078
M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
4.1.1.4. Methyl (E)-3-(1-{4-chloro-2-[(2,3-dimethoxyphenyl)
(hydroxy)methyl]phenyl}-1H-pyrrol-2-yl)-2-propenoate
centrated in vacuo. The residue was purified by preparative TLC
(methanol–chloroform = 1:100) to give the title compound
9
(6).
Compound 5 (1.20 g, 2.82 mmol) was dissolved in metha-
(83 mg, 0.15 mmol, 77%). MS (ESI) m/z 567 (M+H)+. 1H NMR
(CDCl3) d 1.06–1.23 (2H, m), 1.26 (3H, t, J = 7.1 Hz), 1.72–1.80
(2H, m), 1.95–2.06 (1H, m), 2.11–2.17 (1H, m), 2.22–2.27 (1H,
m), 2.54–2.70 (1H, m), 2.79–2.91 (1H, m), 2.95–3.13 (1H, m),
3.22–3.30 (1H, m), 3.42 (3H, s), 3.85 (3H, s), 4.01–4.07 (1H, m),
4.09–4.17 (2H, m), 4.61–4.73 (1H, m), 4.91–5.01 (1H, m), 5.72–
5.75 (1H, m), 6.23–6.25 (1H, m), 6.35–6.37 (1H, m), 6.67–6.71
(1H, m), 6.92–6.96 (1H, m), 7.08–7.10 (1H, m), 7.13–7.19 (1H,
m), 7.23–7.31 (1H, m), 7.33–7.37 (2H, m).
nol (30 ml). To the resulting solution was added sodium borohy-
dride (160 mg, 4.23 mmol), followed by stirring at room
temperature for 1 h. Water was added to the reaction mixture,
and then the organic materials were extracted with ethyl acetate.
The organic layer was dried over Na2SO4, and then concentrated
in vacuo to give the title compound 6 (1.25 g, 2.82 mmol, 100%).
MS (ESI) m/z 428 (M+H)+. 1H NMR (CDCl3) d 3.50 (1.5H, s), 3.53
(1.5H, s), 3.64 (1.5H, s), 3.70 (1.5H, s), 3.78 (1.5H, s), 3.83 (1.5H,
s), 5.65–5.71 (1.0H, m), 5.72 (0.5H, d, J = 6.1 Hz), 5.92 (0.5H, d,
J = 15.9 Hz), 6.18 (0.5H, t, J = 3.3 Hz), 6.36 (0.5H, t, J = 3.3 Hz),
6.42–6.45 (0.5H, m), 6.46–6.48 (0.5H, m), 6.62–6.66 (1.0H, m),
6.70–6.77 (1.5H, m), 6.84–6.84 (0.5H, m), 6.86–6.86 (0.5H, m),
6.93–6.95 (0.5H, m), 6.96–7.01 (0.5H, m), 7.11 (0.5H, d, J = 8.3 Hz),
7.15 (0.5H, d, J = 8.3 Hz), 7.23 (0.5H, d, J = 15.9 Hz), 7.36–7.39
(1.0H, m), 7.67 (0.5H, d, J = 2.4 Hz), 7.71 (0.5H, d, J = 2.4 Hz).
4.1.1.8. 2-(1-{2-[8-Chloro-6-(2,3-dimethoxyphenyl)-4H,6H-pyr-
rolo[1,2-a][4,1]benzoxazepin-4-yl]acetyl}-4-piperidinyl)acetic
acid (10).
Compound 9 (83 mg, 0.15 mmol) was dissolved in
methanol–water–tetrahydrofuran (2:1:0.5, 3.5 ml). To the result-
ing solution, potassium carbonate (91 mg, 0.66 mmol) was added,
followed by stirring overnight at room temperature. The tempera-
ture was raised to 45 °C and stirring was continued for a further
7 h. To the reaction mixture, acetic acid (0.038 ml, 0.66 mmol)
was added and the mixture was diluted with chloroform and
washed with brine. The organic layer was dried over Na2SO4, and
then concentrated in vacuo. The residue was purified by prepara-
tive TLC (methanol–chloroform = 1:10) to give the title compound
10 (64 mg, 0.12 mmol, 81%). MS (ESI) m/z 539 (M+H)+. 1H NMR
(CDCl3) d 1.01–1.24 (2H, m), 1.59–1.82 (2H, m), 1.93–2.02 (1H,
m), 2.13–2.15 (1H, m), 2.24–2.28 (1H, m), 2.53–2.69 (1H, m),
2.79–2.91 (1H, m), 2.95–3.12 (1H, m), 3.23–3.32 (1H, m), 3.41
(3H, s), 3.85 (3H, s), 4.02–4.06 (1H, m), 4.62–4.73 (1H, m), 4.90–
4.99 (1H, m), 5.72–5.76 (1H, m), 6.24 (1H, br s), 6.36 (1H, t,
J = 3.2 Hz), 6.68–6.70 (1H, m), 6.92–6.95 (1H, m), 7.08–7.10 (1H,
m), 7.15 (1H, t, J = 7.9 Hz), 7.21–7.36 (3H, m). Anal. Calcd for
4.1.1.5. Methyl 2-[8-chloro-6-(2,3-dimethoxyphenyl)-4H,6H-
pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetate
(7).
Com-
pound 6 (1.25 g, 2.82 mmol) was dissolved in dichloromethane
(30 ml). To the resulting solution, trifluoroacetic acid (0.270 ml,
3.51 mmol) was added and the mixture was stirred overnight at
room temperature. The reaction mixture was diluted with chloro-
form and then washed with satd NaHCO3 aq and brine. The organic
layer was dried over Na2SO4, and then concentrated in vacuo. The
residue was purified by silica gel column chromatography (ethyl
acetate–hexane = 1:15) to give the title compound 7 (627 mg,
1.46 mmol, 52%). MS (ESI) m/z 462 (M+H)+. 1H NMR (CDCl3) d
3.02 (1H, dd, J = 15.0, 6.0 Hz), 3.10 (1H, dd, J = 15.0, 8.2 Hz), 3.44
(3H, s), 3.71 (3H, s), 3.85 (3H, s), 4.90 (1H, dd, J = 8.2, 6.0 Hz),
5.71 (1H, s), 6.28–6.29 (1H, m), 6.37 (1H, t, J = 3.2 Hz), 6.72 (1H,
d, J = 2.0 Hz), 6.94 (1H, dd, J = 8.0, 1.5 Hz), 7.09–7.12 (1H, m), 7.16
(1H, t, J = 8.0 Hz), 7.23–7.27 (1H, m), 7.35–7.37 (2H, m). Anal. Calcd
for C23H22NO5ClÁ0.25 1,4-dioxane: C, 64.07; H, 5.38; N, 3.11.
Found: C, 63.89; H, 5.41; N, 3.00.
C
29H31N2O6ClÁ0.75 1,4-dioxane: C, 63.52; H, 6.16; N, 4.63. Found:
C, 63.12; H, 5.91; N, 4.64.
4.1.1.9. Methyl 2-[1,8-dichloro-6-(2,3-dimethoxyphenyl)-4H,6H-
pyrrolo[1,2-a][4,1] benzoxazepin-4-yl]acetate.
Compound
7 (52 mg, 0.12 mmol) was dissolved in tetrahydrofuran (3 ml). N-
chlorosuccinimide (16.2 mg, 0.12 mmol) was added and the result-
ing mixture was stirred overnight at room temperature. Water was
added to the reaction mixture, followed by extraction with chloro-
form. The organic layer was dried over Na2SO4, and then concen-
trated in vacuo. The residue was purified by preparative TLC
(ethyl acetate–n-hexane = 1:6) to give the title compound
(52 mg, 0.11 mmol, 93%). MS (ESI) m/z 462 (M+H)+. 1H NMR
(CDCl3) d 2.99 (1H, dd, J = 15.3, 6.5 Hz), 3.06 (1H, dd, J = 15.3,
7.8 Hz), 3.42 (3H, s), 3.71 (3H, s), 3.85 (3H, s), 4.72–4.74 (1H, m),
5.62 (1H, s), 6.23 (1H, d, J = 3.9 Hz), 6.29 (1H, d, J = 3.9 Hz), 6.76
(1H, d, J = 2.4 Hz), 6.94 (1H, dd, J = 7.9, 1.3 Hz), 7.16 (1H, t,
J = 7.9 Hz), 7.21–7.22 (1H, m), 7.41 (1H, dd, J = 8.5, 2.4 Hz), 7.51
(1H, d, J = 8.5 Hz).
4.1.1.6.
2-[8-Chloro-6-(2,3-dimethoxyphenyl)-4H,6H-pyrrol-
Compound
o[1,2-a][4,1]benzoxazepin-4-yl]acetic acid (8).
7 (142 mg, 0.33 mmol) was dissolved in methanol–water–tetrahy-
drofuran (2:1:0.5, 3.5 ml). To the resulting mixture, potassium car-
bonate (206 mg, 1.50 mmol) was added, followed by stirring
overnight at room temperature. After addition of acetic acid
(0.086 ml, 1.50 mmol), the resulting mixture was diluted with
chloroform and washed with water. The organic layer was dried
over Na2SO4, and then concentrated in vacuo. The residue was
purified by preparative TLC (methanol–chloroform = 1:10) to give
the title compound 8 (81 mg, 0.19 mmol, 57%, trans–cis = 10:1).
MS (ESI) m/z 414 (M+H)+. 1H NMR (CDCl3) d 2.98–3.12 (2H, m),
3.44 (3H, s), 3.84 (3H, s), 4.82–4.90 (1H, m), 5.72 (1H, s), 6.24–
6.37 (2H, m), 6.71–6.75 (1H, m), 6.92 (1H, d, J = 8.1 Hz), 7.08–
7.10 (1H, m), 7.14 (1H, t, J = 8.1 Hz), 7.25–7.28 (1H, m), 7.33–7.36
(2H, m). Anal. Calcd for C22H20NO5ClÁ0.75 1,4-dioxane: C, 62.57;
H, 5.46; N, 2.92. Found: C, 62.41; H, 5.51; N, 2.66.
4.1.1.10. 2-[1,8-Dichloro-6-(2,3-dimethoxyphenyl)-4H,6H-pyr-
rolo[1,2-a][4,1]benzoxazepin-4-yl]acetic acid (11).
Methyl
2-(1,8-chloro-6-(2,3-dimethoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]
benzoxazepin-4-yl)acetate (73 mg, 0.16 mmol) was treated by
using potassium carbonate (66 mg, 0.47 mmol) to give the title
compound 11 (28 mg, 0.06 mmol, 40%), in a similar manner de-
scribed for 8. MS (ESI) m/z 449 (M+H)+. 1H NMR (CDCl3) d 2.94–
3.06 (2H, m), 3.42 (3H, s), 3.84 (3H, s), 4.69 (1H, t, J = 6.3 Hz),
5.63 (1H, s), 6.24 (1H, d, J = 3.7 Hz), 6.27 (1H, d, J = 3.7 Hz), 6.75–
6.78 (1H, m), 6.92 (1H, d, J = 7.9 Hz), 7.13 (1H, t, J = 7.9 Hz), 7.22
(1H, d, J = 7.9 Hz), 7.39 (1H, dd, J = 8.5, 2.2 Hz), 7.49 (1H, d,
J = 8.5 Hz). Anal. Calcd for C22H19NO5Cl2Á0.5H2OÁ0.1 1,4-dioxane:
C, 57.72; H, 4.50; N, 3.00. Found: C, 57.28; H, 4.80; N, 2.66.
4.1.1.7. Ethyl
4H,6H-pyrrolo[1,2-a][4,1] benzoxazepin-4-yl]acetyl}-4-piperid-
inyl)acetate (9). Compound 8 (81 mg, 0.19 mmol) and ethyl
2-(4-piperidinyl)acetate (36 mg, 0.21 mmol) were dissolved in
dichloromethane (3 ml). To the solution, 1-ethyl-3-(3-dimethyl-
aminopropyl)carbodiimide hydrochloride (44 mg, 0.23 mmol) and
1-hydroxybenzotriazole (9 mg, 0.06 mmol) were added, followed
by stirring at room temperature for 3 h. The reaction mixture
was diluted with chloroform and washed with satd NaHCO3 aq
and brine. The organic layer was dried over Na2SO4, and then con-
2-(1-{2-[8-chloro-6-(2,3-dimethoxyphenyl)-

M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
3079
4.1.1.11. Methyl
[(dimethylamino)methyl]-4H,6H-pyrrolo[1,2-a][4,1]benzoxaze-
pin-4-yl}acetate. Thirty-eight percentage of formaldehyde
2-{8-chloro-6-(2,3-dimethoxyphenyl)-1-
4.1.1.15.
Ethyl
2-(1-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxy-
phenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetyl}-
4-piperidinyl)acetate ((4R,6S)-14a) and ethyl 2-(1-{2-[(4S,6R)-8-
chloro-6-(2,3-dimethoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]
benzoxazepin-4-yl]acetyl}-4-piperidinyl)acetate
14a).
(0.055 ml) and 50% dimethylamine in water (0.11 ml) were dis-
solved in acetic acid (1 ml). The mixture was added to the acetic
acid solution (2 ml) of compound 7 (60 mg, 0.14 mmol). Then,
the reaction mixture was stirred at room temperature for 15 h
and concentrated in reduced pressure. The residue was dissolved
in ethyl acetate and washed with saturated NaHCO3 solution. The
combined organic layer was washed with brine. The organic layer
was dried over Na2SO4, and then concentrated in vacuo. The resi-
due was purified by preparative TLC (methanol–chloroform = 1:10)
to give the title compound (70 mg, 0.14 mmol, 100%). MS (ESI) m/z
485 (M+H)+. 1H NMR (CDCl3) d 2.19 (6H, s), 3.00 (1H, dd, J = 15.0,
6.0 Hz), 3.08 (1H, dd, J = 15.0, 8.2 Hz), 3.39 (3H, s), 3.43 (1H, d,
J = 13.9 Hz), 3.50 (1H, d, J = 13.9 Hz), 3.71 (3H, s), 3.84 (3H, s),
4.77 (1H, dd, J = 8.2, 6.0 Hz), 5.58 (1H, s), 6.21 (1H, d, J = 3.4 Hz),
6.27 (1H, d, J = 3.4 Hz), 6.71 (1H, d, J = 2.4 Hz), 6.93 (1H, dd,
J = 8.1, 1.5 Hz), 7.16 (1H, t, J = 8.1 Hz), 7.24 (1H, dd, J = 8.1,
1.5 Hz), 7.37 (1H, dd, J = 8.5, 2.4 Hz), 7.74 (1H, d, J = 8.5 Hz).
((4S,6R)-
Compound 9 (89.0 mg, 0.157 mmol) was isolated and
purified by HPL [CHIRALCEL OD (Daicel, 50
u
 500 mm), eluting sol-
vent 20% 2-propanol–n-hexane, dissolution rate: 10 ml/min], where-
by the (4R,6S)-14a (30.2 mg) was obtained from the fraction with a
retention time of 19 min and the (4S,6R)-14a (33.3 mg) was obtained
from the fraction with a retention time of 35 min, respectively.
4.1.1.16.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetyl}-4-piperidi-
nyl)acetic acid ((4R,6S)-15a). Compound (4R,6S)-14a
2-(1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
(30.2 mg, 0.053 mmol) was dissolved in methanol–water–tetrahy-
drofuran (2:1:0.5, 3.5 ml). To the solution, potassium carbonate
(22.1 mg, 0.160 mmol) was added and the resulting mixture was
stirred overnight at room temperature. After the temperature
was raised to 45 °C, stirring was continued for a further 7 h. After
addition of acetic acid (0.0091 ml, 0.128 mmol), the resulting mix-
ture was diluted with chloroform and washed with brine. The or-
ganic layer was dried over Na2SO4, and then concentrated in
vacuo. The residue was purified by preparative TLC (methanol–
chloroform = 1:10) to give the title compound (4R,6S)-15a
(24.1 mg, 0.045 mmol, 84%). The acid was dissolved in ethanol.
To the solution, equivalent 1 N sodium hydroxide was added at
room temparature and concentrated in vacuo. The residue was
solidified by diisopropyl ether–n-hexane. Then the solid was fil-
trated out and dried in vacuo to obtain sodium salt of (4R,6S)-
15a. MS (ESI) m/z 539 (M+H)+. 1H NMR (CDCl3) d 1.01–1.24 (2H,
m), 1.59–1.82 (2H, m), 1.93–2.02 (1H, m), 2.13–2.15 (1H, m),
2.24–2.28 (1H, m), 2.53–2.69 (1H, m), 2.79–2.91 (1H, m), 2.95–
3.12 (1H, m), 3.23–3.32 (1H, m), 3.41 (3H, s), 3.85 (3H, s), 4.02–
4.06 (1H, m), 4.62–4.73 (1H, m), 4.90–4.99 (1H, m), 5.72–5.76
(1H, m), 6.24 (1H, brs), 6.36 (1H, t, J = 3.2 Hz), 6.68–6.70 (1H, m),
6.92–6.95 (1H, m), 7.08–7.10 (1H, m), 7.15 (1H, t, J = 7.9 Hz),
4.1.1.12.
amino)methyl]-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl}
acetic acid (12). Methyl 2-{8-chloro-6-(2,3-dimethoxy-
2-{8-Chloro-6-(2,3-dimethoxyphenyl)-1-[(dimethyl-
phenyl)-1-[(dimethylamino)methyl]-4H,6H-pyrrolo[1,2-a][4,1]ben
zoxazepin-4-yl}acetate (70 mg, 0.14 mmol) was treated by using
potassium carbonate (80 mg, 0.58 mmol) to give the title com-
pound 12 (34 mg, 0.07 mmol, 49%), in a similar manner described
for 8. MS (ESI) m/z 471 (M+H)+. 1H NMR (CDCl3) d 2.21 (6H, s), 2.97
(2H, d, J = 6.8 Hz), 3.37 (3H, s), 3.68 (1H, d, J = 13.9 Hz), 3.83 (3H, s),
3.88 (1H, d, J = 13.9 Hz), 4.72 (1H, t, J = 6.8 Hz), 5.54 (1H, s), 6.30
(2H, s), 6.71–6.71 (1H, m), 6.91 (1H, d, J = 8.3 Hz), 7.12 (1H, t,
J = 8.3 Hz), 7.29–7.31 (2H, m), 7.38 (1H, d, J = 8.3 Hz). Anal. Calcd
for C25H27N2O5ClÁ1H2OÁ1.75 1,4-dioxane: C, 59.76; H, 6.74; N,
4.36. Found: C, 59.28; H, 6.43; N, 4.85.
4.1.1.13. Methyl 2-[8-chloro-6-(2,3-dimethoxyphenyl)-1-(4-mor
pholinylmethyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]
7.21–7.36 (3H, m). Anal. Calcd for
60.16; H, 5.57; N, 4.84. Found: C, 60.11; H, 5.83; N, 4.51.
C
29H30N2O6ClNaÁ1H2O: C,
acetate.
Compound 7 (56 mg, 0.13 mmol) was treated by
using 38% formaldehyde (0.050 ml) and morphorine (0.034 ml,
0.39 mmol) to give the title compound (69 mg, 0.13 mmol, 100%),
in a similar manner described for 8. MS (ESI) m/z 527 (M+H)+. 1H
NMR (CDCl3) d 2.33–2.41 (2H, m), 2.53–2.61 (2H, m), 3.00 (1H,
dd, J = 15.0, 6.0 Hz), 3.08 (1H, dd, J = 15.0, 8.1 Hz), 3.41 (3H, s),
3.43–3.52 (2H, m), 3.66–3.71 (4H, m), 3.71 (3H, s), 3.84 (3H, s),
4.76–4.81 (1H, m), 5.53 (1H, s), 6.21 (1H, d, J = 3.4 Hz), 6.26 (1H,
d, J = 3.4 Hz), 6.92–6.96 (1H, m), 7.16 (1H, t, J = 7.9 Hz), 7.23 (1H,
d, J = 7.9 Hz), 7.36 (1H, dd, J = 8.5, 2.2 Hz), 7.94 (1H, d, J = 8.5 Hz).
4.1.1.17.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetyl}-4-piperidi-
nyl)acetic acid (4S,6R)-15a). Compound (4S,6R)-14a
2-(1-{2-[(4S,6R)-8-Chloro-6-(2,3-dimethoxyphenyl)-
(33.3 mg, 0.059 mmol) was treated by using potassium carbonate
(24.3 mg, 0.176 mmol) to give the title compound (4S,6R)-15a
(20.4 mg, 0.038 mmol, 64%), in a similar manner described for
(4R,6S)-15a. MS (ESI) m/z 539 (M+H)+. 1H NMR (CDCl3) d 1.01–
1.24 (2H, m), 1.59–1.82 (2H, m), 1.93–2.02 (1H, m), 2.13–2.15
(1H, m), 2.24–2.28 (1H, m), 2.53–2.69 (1H, m), 2.79–2.91 (1H,
m), 2.95–3.12 (1H, m), 3.23–3.32 (1H, m), 3.41 (3H, s), 3.85 (3H,
s), 4.02–4.06 (1H, m), 4.62–4.73 (1H, m), 4.90–4.99 (1H, m),
5.72–5.76 (1H, m), 6.24 (1H, brs), 6.36 (1H, t, J = 3.2 Hz), 6.68–
6.70 (1H, m), 6.92–6.95 (1H, m), 7.08–7.10 (1H, m), 7.15 (1H, t,
4.1.1.14. 2-[8-Chloro-6-(2,3-dimethoxyphenyl)-1-(4-morpholi-
nylmethyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetic
acid (13).
Methyl 2-[8-chloro-6-(2,3-dimethoxyphenyl)-1-
J = 7.9 Hz),
29H31N2O6ClÁ1.5H2OÁ0.5 CHCl3Á0.5 1,4-dioxane: C, 56.83; H, 5.81;
N, 4.14. Found: C, 57.01; H, 5.60; N, 3.85.
7.21–7.36
(3H,
m).
Anal.
Calcd
for
(4-morpholinylmethyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-
yl]acetate (69 mg, 0.13 mmol) was treated by using potassium car-
bonate (110 mg, 0.78 mmol) to give the title compound 13 (25 mg,
0.05 mmol, 37%), in a similar manner described for 8. MS (ESI) m/z
513 (M+H)+. 1H NMR (CDCl3) d 2.33–2.41 (2H, m), 2.50–2.57 (2H,
m), 2.97–3.04 (2H, m), 3.41 (3H, s), 3.51 (1H, d, J = 13.9 Hz), 3.59
(1H, d, J = 13.9 Hz), 3.64–3.69 (4H, m), 3.83 (3H, s), 4.71–4.77
(1H, m), 5.54 (1H, s), 6.21–6.27 (2H, m), 6.73 (1H, d, J = 2.4 Hz),
6.90 (1H, d, J = 8.0 Hz), 7.12 (1H, t, J = 8.0 Hz), 7.23–7.26 (1H, m),
7.34 (1H, dd, J = 8.5, 2.4 Hz), 7.79 (1H, d, J = 8.5 Hz). Anal. Calcd
for C25H27N2O5ClÁ1H2OÁ1.75 1,4-dioxane: C, 59.76; H, 6.74; N,
4.36. Found: C, 59.28; H, 6.43; N, 4.85.
C
4.1.1.18. [5-Chloro-2-(1H-pyrrol-1-yl)phenyl](1-naphthyl)meth-
anol (17A).
1-(2-Bromo-4-chlorophenyl)-1H-pyrrole17 (16,
6.00 g, 23.4 mmol) was dissolved in diethyl ether (200 ml). n-Butyl
lithium (1.6 M in n-hexane, 18.00 ml, 28.1 mmmol) was dropwised
to the resulting solution at À78 °C. The reaction mixture was stir-
red for 1 h and gradually warmed to ice-cooling temperature. To
the solution, 1-naphthaldehyde (3.81 ml, 28.1 mmol) was added
under ice-cooling, followed by stirring for 30 min. Satd NH4Cl aq

3080
M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
was added to the reaction mixture, and then organic materials
were extracted with ethyl acetate. After the organic layer was dried
over Na2SO4, the solvent was distilled off under reduced pressure.
The residue was purified by silica gel column chromatography
(ethyl acetate–n-hexane = 1:20) to give the title compound 17A
(5.78 g, 17.3 mmol, 74%). MS (EI) m/z 333 (M+H)+. 1H NMR (CDCl3)
d 6.25–6.28 (2H, m), 6.48 (1H, s), 6.80–6.84 (2H, m), 7.24–7.52 (5H,
m), 7.56–7.63 (2H, m), 7.79–7.86 (2H, m).
4.1.1.22. 2-[8-Chloro-6-(1-naphthyl)-4H,6H-pyrrolo[1,2-a][4,1]
benzoxazepin-4-yl]acetic acid (19A). Methyl 2-[8-chloro-6-
(1-naphthyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetate
(300 mg, 0.73 mmol) was dissolved in the mixture of tetrahydrofu-
ran (5 ml), methanol (3 ml) and 1 N sodium hydroxide aqueous
solution (1.16 ml). The resulting mixture was stirred overnight at
room temperature, and then concentrated in vacuo. Chloroform
and a 10% aqueous citric acid solution were added to the residue,
and the layers were separated. The organic layer was dried over
Na2SO4, the solvent was distilled off under reduced pressure to
give the title compound 19A (153 mg, 0.38 mmol, 48%). MS (EI)
m/z 403 M+. 1H NMR (CDCl3) d 3.11–3.18 (1H, m), 3.18–3.25 (1H,
m), 5.01–5.07 (1H, m), 6.11 (1H, s), 6.37–6.41 (1H, m), 6.43–6.47
(1H, m), 6.62 (1H, s), 7.20–7.23 (1H, m), 7.25–7.33 (2H, m), 7.37–
7.49 (3H, m), 7.56 (1H, t, J = 7.8 Hz), 7.80–7.91 (3H, m). Anal. Calcd
for C29H28ClN3O8Á0.5H2OÁ0.2CHCl3: C, 66.74; H, 4.41; N, 3.19.
Found: C, 66.87; H, 4.24; N, 3.22.
4.1.1.19. 1-[4-Chloro-2-(1-naphthoyl)phenyl]-1H-pyrrol-2-carb-
aldehyde.
Compound 17A (5.78 g, 17.3 mmol) was dissolved
in dichloromethane (200 ml). To the resulting mixture, manganese
dioxide (15.1 g, 170 mmol) was added and stirred overnight at
50 °C. The reaction mixture was filtered through a Kiriyama funnel.
The filtrate was concentrated under reduced pressure. Then, phos-
phorus oxychloride (4.84 ml, 51.9 mmol) was dissolved in dichlo-
romethane (200 ml). To the solution, N,N-dimethylformamide
(5.36 ml, 69.2 mmol) was added dropwise under ice-cooling, fol-
lowed by stirring for 20 min. A dichloromethane solution (50 ml)
of the previously-obtained residue was added dropwise to the
ice-cooling reaction mixture, followed by stirring at room temper-
ature for 3 h. An aqueous solution (200 ml) of sodium acetate
(21.3 g, 260 mmol) was added to the reaction mixture and the or-
ganic materials were extracted with dichloromethane. The organic
layer was dried over Na2SO4, and then concentrated in vacuo. The
residue was purified by silica gel column chromatography (ethyl
acetate–n-hexane = 1:10) to give the title compound (2.95 g,
8.15 mmol, 47%). MS (EI) m/z 359 M+. 1H NMR (CDCl3) d 5.96 (1H,
dd, J = 4.0, 2.6 Hz), 6.60 (1H, dd, J = 4.0, 1.6 Hz), 6.88 (1H, s),
7.25–7.35 (2H, m), 7.47–7.62 (4H, m), 7.69 (1H, d, J = 2.4 Hz),
7.79–7.83 (1H, m), 7.88 (1H, d, J = 8.3 Hz), 8.54 (1H, d, J = 8.3 Hz),
9.29 (1H, s).
4.1.1.23.
phenyl)methanol (17B).
[5-Chloro-2-(1H-pyrrol-1-yl)phenyl](2,3-dichloro-
Compound 16 (6.00 g, 23.4 mmo)
was treated by using n-butyl lithium hexane solution (18.00 ml,
28.1 mmol) and 2,3-dichlorobenzaldehyde (4.91 g, 28.1 mmol) to
give the title compound 17B (6.10 g, 17.3 mmol, 74%), in a similar
manner described for 17A. MS (EI) m/z 352 M+. 1H NMR (CDCl3) d
6.05 (1H, s), 6.29–6.33 (2H, m), 6.78–6.81 (2H, m), 7.17–7.20
(1H, m), 7.25–7.31 (2H, m), 7.33–7.38 (1H, m), 7.43 (1H, d,
J = 7.8 Hz), 7.52 (1H, d, J = 7.8 Hz).
4.1.1.24. 1-[4-Chloro-2-(2,3-dichlorobenzoyl)phenyl]-1H-pyr-
rol-2-carbaldehyde.
Compound 17B (6.10 g, 17.3 mmol)
was treated by using manganese dioxide (15.0 g, 170 mmol), phos-
phorus oxychloride (4.84 ml, 51.9 mmol) and N,N-dimethylform-
amide (5.36 ml, 69.2 mmol) to give the title compound (3.43 g,
9.1 mmol, 55%), in a similar manner described for 1-[4-chloro-2-
(1-naphthoyl)phenyl]-1H-pyrrol-2-carbaldehyde, via 18B. MS (EI)
m/z 378 M+. 1H NMR (CDCl3) d 6.21–6.24 (1H, m), 6.79–6.82 (1H,
m), 6.90 (1H, s), 7.06–7.19 (2H, m), 7.29 (1H, d, J = 8.5 Hz), 7.42–
7.45 (1H, m), 7.60 (1H, dd, J = 8.5, 2.0 Hz), 7.71 (1H, d, J = 2.0 Hz),
9.35 (1H, s).
4.1.1.20. Methyl (E)-3-{1-[4-chloro-2-(1-naphthoyl)phenyl]-1H-
pyrrol-2-yl}-2-propenoate.
Compound 18A (2.95 g, 8.20
mmol) was treated by using methyl (trimethylphosphoranylid-
ene)acetate (7.13, 21.3 mmol) to give the title compound (3.18 g,
7.61 mmol, 93%), in a similar manner described for 5. MS (FAB)
m/z 415 (M+H)+. 1H NMR (CDCl3) d 3.75 (3H, s), 5.76–5.84 (2H,
m), 6.18–6.21 (1H, m), 6.65–6.68 (1H, m), 7.16 (1H, d,
J = 15.6 Hz), 7.20–7.27 (2H, m), 7.30 (1H, d, J = 8.5 Hz), 7.34 (1H,
d, J = 7.1 Hz), 7.46–7.56 (2H, m), 7.64 (1H, dd, J = 8.5, 2.4 Hz),
7.75–7.81 (2H, m), 7.84 (1H, d, J = 8.1 Hz), 8.48 (1H, d, J = 8.1 Hz).
4.1.1.25. Methyl (E)-3-{1-[4-chloro-2-(2,3-dichlorobenzoyl) phe-
nyl]-1H-pyrrol-2-yl}-2-propenoate.
lorobenzoyl)phenyl]-1H-pyrrol-2-carbaldehyde
1-[4-Chloro-2-(2,3-dich
(3.42 g, 9.03
4.1.1.21. Methyl 2-[8-chloro-6-(1-naphthyl)-4H,6H-pyrrolo[1,2-
mmol) was treated by using methyl (trimethylphosphoranylid-
ene)acetate (7.85 g, 23.5 mmol) to give the title compound
(4.05 g, 9.03 mmol, quant.), in a similar manner described for 5.
MS (EI) m/z 433 M+. 1H NMR (CDCl3) d 3.73(3H, s), 5.88 (1H, d,
J = 15.9 Hz), 6.03–6.07 (1H, m), 6.37–6.42 (1H, m), 6.66–6.70 (1H,
m), 6.99–7.05 (2H, m), 7.12 (1H, d, J = 15.9 Hz), 7.23–7.28 (2H,
m), 7.35–7.41 (1H, m), 7.65 (1H, dd, J = 8.3, 2.4 Hz), 7.81 (1H, d,
J = 2.4 Hz).
a][4,1]benzoxazepin-4-yl]acetate.
Methyl (E)-3-{1-[4-chloro-
2-(1-naphthoyl)phenyl]-1H-pyrrol-2-yl}-2-propenoate (100 mg,
0.24 mmol) was dissolved in methanol (3 ml). Sodium borohydride
(18 mg, 0.48 mmol) was added to the solution. The reaction mix-
ture was stirred at room temperature for 1 h, and then concen-
trated in vacuo. Water and ethyl acetate were added to the
residue, and the organic layer was separated and dried over
Na2SO4, and then concentrated in vacuo. The residue was dissolved
in dichloromethane (5 ml). To the solution, trifluoroacetic acid
(0.028 ml, 0.36 mmol) was added and stirred overnight at room
temperature. To the reaction mixture, satd NaHCO3 aq was added,
and the layers were separated. The organic layer was dried over
Na2SO4. The solvent was distilled off under reduced pressure. The
residue was purified by silica gel column chromatography (ethyl
acetate–n-hexane = 1:9) to give the title compound (63 mg,
0.15 mmol, 63%). MS (FAB) m/z 418 (M+H)+. 1H NMR (CDCl3) d
3.07 (1H, dd, J = 15.1, 5.6 Hz), 3.16 (1H, dd, J = 15.1, 8.3 Hz), 3.74
(3H, s), 5.04 (1H, dd, J = 8.3, 5.6 Hz), 6.07 (1H, s), 6.30–6.37 (1H,
m), 6.40–6.44 (1H, m), 6.59 (1H, d, J = 2.2 Hz), 7.18–7.22 (1H, m),
7.26–7.33 (2H, m), 7.34–7.46 (3H, m), 7.49–7.61 (1H, m), 7.80–
7.92 (3H, m).
4.1.1.26.
Methyl
2-[8-chloro-6-(2,3-dichlorobenzoyl)-4H,
Methyl (E)-
6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetate.
3-{1-[4-chloro-2-(2,3-dichlorobenzoyl)phenyl]-1H-pyrrol-2-yl}-
2-propenoate (100 mg, 0.23 mmol) was treated by using sodium boro
hydride (17 mg, 0.46 mmol) and trifluoroacetic acid (0.027 ml,
0.34 mmol) to give the title compound (73 mg, 0.17 mmol, 73%), in
a similar manner described for 6 and 7. MS (FAB) m/z 436 (M+H)+.
1H NMR (CDCl3) d 3.03 (1H, dd, J = 15.1, 5.7 Hz), 3.11 (1H, dd,
J = 15.1, 8.3 Hz), 3.73 (3H, s), 4.91 (1H, dd, J = 8.3, 5.7 Hz), 5.68 (1H,
s), 6.29–6.32 (1H, m), 6.39 (1H, t, J = 3.3 Hz), 6.56 (1H, d, J = 2.2 Hz),
7.11–7.14 (1H, m), 7.33–7.45 (3H, m), 7.50 (1H, dd, J = 7.8, 1.5 Hz),
7.71 (1H, d, J = 7.8 Hz).

M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
3081
4.1.1.27.
2-[8-Chloro-6-(2,3-dichlorobenzoyl)-4H,6H-pyrrol-
Methyl
t, J = 7.8 Hz), 6.99 (1H, dd, J = 8.1, 1.5 Hz), 7.22 (1H, dd, J = 8.8,
2.4 Hz), 7.31 (1H, d, J = 2.4 Hz). IR (ATR) cmÀ1 3452, 3336, 1624,
1468, 1281, 1088, 926, 804, 733.
o[1,2-a][4,1]benzoxazepin-4-yl]acetic acid (19B).
2-[8-chloro-6-(2,3-dichlorobenzoyl)-4H,6H-pyrrolo[1,2-a][4,1]-
benzoxazepin-4-yl]acetate (200 mg, 0.46 mmol) was treated by
using 1 N aqueous sodium hydroxide solution (0.733 ml,
0.73 mmol) to give the title compound 19B (61 mg, 0.14 mmol,
32%), in a similar manner described for 19A. MS (EI) m/z 421 M+.
1H NMR (CDCl3) d 3.04–3.19 (2H, m), 4.88–4.95 (1H, m), 5.70
(1H, s), 6.32–6.37 (1H, m), 6.38–6.42 (1H, m), 6.57 (1H, d,
J = 2.2 Hz), 7.13–7.15 (1H, m), 7.31–7.45 (3H, m), 7.50 (1H, d,
J = 8.1 Hz), 7.73 (1H, d, J = 8.1 Hz). Anal. Calcd for C20H14Cl3NO3:
C, 56.83; H, 3.34; N, 3.31. Found: C, 56.44; H, 3.54; N, 3.14.
4.1.1.32. [5-Chloro-2-(1H-pyrrol-1-yl)phenyl](2,3-dihydro-1,4-
benzodioxin-5-yl)methanone (18C).
The title compound
18C (2.07 g, 6.09 mmol, 82%) was obtained from compound 23
(2.14 g, 7.39 mmol) by using 2,5-dimethoxytetrahydrofuran
(0.977 ml, 7.55 mmol), in a similar manner described for com-
pound 3. MS (ESI) m/z 340 (M+H)+. 1H NMR (CDCl3) d 4.11–4.16
(2H, m), 4.19–4.22 (2H, m), 6.05 (2H, t, J = 2.2 Hz), 6.66 (2H, t,
J = 2.2 Hz), 6.69 (1H, d, J = 7.8 Hz), 6.84–6.90 (2H, m), 7.29 (1H, d,
J = 8.6 Hz), 7.50 (1H, dd, J = 8.3, 2.5 Hz), 7.57 (1H, d, J = 2.5 Hz). IR
(ATR) cmÀ1 1664, 1595, 1495, 1469, 1282, 1254, 1090, 924, 806,
754, 725.
4.1.1.28. 2,3-Dihydro-1,4-benzodioxin-5-carbaldehyde.
To
an N,N-dimethylformamide solution (360 ml) of 2,3-dihydroxy-
benzaldehyde (5.16 g, 37.4 mmol) were added 1,2-dibromoethane
(3.86 ml, 44.6 mmol) and potassium carbonate (13.94 g,
100.9 mmol). The resulting mixture was stirred at 70 °C for 3 h.
After the reaction mixture was cooled to room temperature, the so-
lid component was filtered out. The filtrate was concentrated un-
der reduced pressure. The residue was subjected to silica gel
column chromatography (ethyl acetate–n-hexane = 1:5) to give
the title compound (3.90 g, 23.8 mmol, 64%). MS (ESI) m/z 165
(M+H)+. 1H NMR (CDCl3) d 4.31–4.35 (2H, m), 4.38–4.41 (2H, m),
6.91 (1H, t, J = 7.8 Hz), 7.10 (1H, dd, J = 8.1, 1.7 Hz), 7.38–7.41
(1H, m), 10.37 (1H, s). IR (ATR) cmÀ1: 2879, 1680, 1597, 1477,
1282, 1248, 1203, 1082, 887, 781, 723.
4.1.1.33. 1-[4-Chloro-2-(2,3-dihydro-1,4-benzodioxin-5-ylcar-
bonyl)phenyl]-1H-pyrrol-2-carbaldehyde.
The title com-
pound (0.75 g, 2.04 mmol, 52%) was obtained from compound
18C (1.34 g, 3.94 mmol) by using phosphorus oxychloride
(0.441 ml, 4.73 mmol) and N,N-dimethylformamide (0.610 ml,
7.88 mmol), in a similar manner described for 4. MS (ESI) m/z
368 (M+H)+. 1H NMR (CDCl3) d 4.09–4.21 (4H, m), 6.20 (1H, dd,
J = 3.9, 2.7 Hz), 6.68 (1H, t, J = 8.0 Hz), 6.81–6.85 (2H, m), 6.86–
6.90 (2H, m), 7.29 (2H, d, J = 8.3 Hz), 7.53 (1H, dd, J = 8.6, 2.5 Hz),
7.61 (1H, d, J = 2.5 Hz), 9.36 (1H, s). IR (ATR) cmÀ1 1662, 1589,
1468, 1281, 1252, 1086, 1036, 897, 806, 756, 731.
4.1.1.29. tert-Butyl 4-chloro-2-[2,3-dihydro-1,4-benzodioxin-5-
4.1.1.34. Benzyl (E)-3-{1-[4-chloro-2-(2,3-dihydro-1,4-benzodi-
yl(hydroxy)methyl]phenylcarbamate (21).
sec-Butyl lithium
oxin-5-ylcarbonyl)phenyl]-1H-pyrrol-2-yl}-2-propenoate.
The
(0.99 mol/l, 44.3 ml, 43.8 mmol) was added dropwise to a tetrahy-
drofuran solution (140 ml) of tert-butyl 4-chlorophenylcarbamate
(20, 4.16 g, 18.3 mmol) at À78 °C. While warming to -20 °C, the
reaction mixture was stirred for 1.5 h. Under ice-cooling, the mix-
ture was stirred for a further 0.5 h, cooled to À78 °C again, and 2,3-
dihydro-1,4-benzodioxin-5-carbaldehyde (3.90 g, 23.8 mmol) was
added thereto. The reaction mixture was stirred for 2 h while
warming to room temperature. Then, satd NH4Cl aq was added
to the reaction mixture and the layers were separated. The organic
layer was dried over Na2SO4, and then concentrated in vacuo. The
residue was purified by silica gel column chromatography (ethyl
acetate–n-hexane = 1:9) to give the title compound 21 (3.54 g,
9.0 mmol, 49%). MS (ESI) m/z 318 (MÀtBuO)+. 1H NMR (CDCl3) d
1.50 (9H, s), 3.14 (1H, d, J = 4.9 Hz), 4.22–4.37 (4H, m), 6.04 (1H,
d, J = 5.4 Hz), 6.77–6.82 (1H, m), 6.85–6.89 (2H, m), 7.08 (1H, d,
J = 2.5 Hz), 7.23 (1H, dd, J = 8.8, 2.5 Hz), 7.91 (2H, d, J = 8.3 Hz),
7.95 (1H, br s).
title compound (410 mg, 0.82 mmol, 85%) was obtained from
1-[4-chloro-2-(2,3-dihydro-1,4-benzodioxin-5-ylcarbonyl)phenyl]-
1H-pyrrol-2-carbaldehyde (355 mg, 0.98 mmol) by using benzyl(tri-
phenylphosphoranylidene)acetate (429 mg, 1.05 mmol), in a simi-
lar manner described for 5. MS (ESI) m/z 500 (M+H)+. 1H NMR
(CDCl3) d 3.94–4.06 (4H, m), 5.16 (2H, d, J = 5.6 Hz), 6.03 (1H, d,
J = 15.7 Hz), 6.10–6.12 (1H, m), 6.54 (1H, dd, J = 4.0, 1.3 Hz), 6.64–
6.69 (1H, m), 6.76 (1H, q, J = 1.4 Hz), 6.84 (1H, dd, J = 8.1, 1.5 Hz),
6.88 (1H, dd, J = 7.8, 1.7 Hz), 7.20 (1H, d, J = 8.3 Hz), 7.29–7.40
(6H, m), 7.55 (1H, dd, J = 8.3, 2.5 Hz), 7.61 (1H, d, J = 2.5 Hz). IR
(ATR) cmÀ1 1699, 1620, 1450, 1282, 1244, 1142, 1088, 727.
4.1.1.35. Benzyl (E)-3-(1-{4-chloro-2-[2,3-dihydro-1,4-benzodi-
oxin-5-yl(hydroxy)methyl]phenyl}-1H-pyrrol-2-yl)-2-propeno-
ate.
The title compound (430 mg, 0.81 mmol, 100%) was
obtained from benzyl (E)-3-{1-[4-chloro-2-(2,3-dihydro-1,4-ben-
zodioxin-5-ylcarbonyl)phenyl]-1H-pyrrol-2-yl}-2-propenoic acid
(406 mg, 0.81 mmol) by using sodium borohydride (50 mg,
1.32 mmol), in a similar manner described for 6. MS (ESI) m/z
484 (MÀOH)+. 1H NMR (CDCl3) d 3.68 (1H, d, J = 17.2 Hz), 3.86–
4.15 (4H, m), 4.70 (1H, d, J = 5.9 Hz), 5.13 (1H, d, J = 17.4 Hz),
5.74–6.01 (2H, m), 6.14–6.17 and 6.52–6.57 (1H, m), 6.29–6.37
(1H, m), 6.65–6.78 (4H, m), 6.86–7.00 (1H, m), 7.08–7.12 (1H,
m), 7.28–7.40 (5H, m), 7.54 and 7.79 (1H, d, J = 2.5 Hz). IR (ATR)
cmÀ1 1685, 1618, 1473, 1450, 1279, 1244, 1165, 1088, 1036, 957,
731.
4.1.1.30. tert-Butyl 4-chloro-2-(2,3-dihydro-1,4-benzodioxin-5-
ylcarbonyl)phenylcarbamate (22).
The title compound 22
(3.16 g, 8.11 mmol, 90%) was prepared from compound 21
(3.53 g, 9.01 mmol) by using manganese dioxide (7.83 g), in a sim-
ilar manner described for compound 18A.
MS (ESI) m/z 290 (MÀtBuO)+. 1H NMR (CDCl3) d 1.53 (9H, s),
4.20–4.25 (2H, m), 4.27–4.31 (2H, m), 6.86 (1H, dd, J = 7.6,
1.7 Hz), 6.93 (1H, t, J = 7.6 Hz), 7.04 (1H, dd, J = 7.8, 1.5 Hz), 7.44–
7.48 (2H, m), 8.47 (1H, dd, J = 7.4, 2.5 Hz), 10.65 (1H,s). IR (ATR)
cmÀ1 3276, 2979, 1728, 1641, 1574, 1506, 1248, 1147, 1086, 829.
4.1.1.36. Benzyl 2-[8-chloro-6-(2,3-dihydro-1,4-benzodioxin-5-
yl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetate.
title compound (177 mg, 0.35 mmol, 42%) was obtained from ben-
zyl (E)-3-(1-{4-chloro-2-[2,3-dihydro-1,4-benzodioxin-5-yl(hy-
droxy)methyl]phenyl}-1H-pyrrol-2-yl)-2-propenoate (418 mg,
0.83 mmol) by using trifluoroacetic acid (0.077 ml), in a similar
manner described for 7. MS (ESI) m/z 502 (M+H)+. 1H NMR (CDCl3)
d 2.46–2.76 and 2.98–3.19 (2H, m), 3.66 and 3.71 (1H, s), 3.96–4.01
and 4.03–4.08 (2H, m), 4.10–4.16 (2H, m), 4.87–4.95 (1H, m), 5.10
The
4.1.1.31. (2-Amino-5-chlorophenyl)(2,3-dihydro-1,4-benzodiox-
in-5-yl)methanone (23).
In accordance with the reported
process,18 the title compound 23 (2.15 g, 7.41 mmol, 92%) was pre-
pared from compound 22 (3.16 g, 8.11 mmol) by using trifluoro-
acetic acid (8.2 ml). MS (ESI) m/z 290 (M+H)+. 1H NMR (CDCl3) d
1.55 (9H, s), 4.22–4.25 (2H, m), 4.28–4.32 (2H, m), 6.38 (2H, br
s), 6.65 (1H, d, J = 8.8 Hz), 6.83 (1H, dd, J = 7.6, 1.7 Hz), 6.91 (1H,

3082
M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
and 5.17 (1H, s), 5.65 and 5.66 (1H, s), 6.26–6.33 (1H, m), 6.35–6.38
(1H, m), 6.76–6.82 (1H, m), 6.85–7.02 (2H, m), 7.09–7.15 and 7.20–
7.24 (2H, m), 7.30–7.41 (7H, m). IR (ATR) cmÀ1 1736, 1604, 1473,
1281, 1171, 1099, 1051, 889, 823, 717.
C
28H30ClN3O6Á1.0H2O: C, 60.27; H, 5.78; N, 7.53. Found: C, 59.90;
H, 5.76; N, 7.12.
4.1.1.41.
2-({2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetyl}amino)ace-
4.1.1.37. 2-[8-Chloro-6-(2,3-dihydro-1,4-benzodioxin-5-yl)-4H,
tic acid (15e).
Methyl 2-({2-[(4R,6S)-8-chloro-6-(2,3-dime-
6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetic
(19C). To an ethyl acetate solution (8 ml) of benzyl 2-[8-
acid
thoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetyl}-
amino)acetate (63 mg, 0.13 mmol, prepared from 8) was treated by
using potassium carbonate (72 mg, 0.52 mmol) to give the title
compound 15e (51.7 mg, 0.11 mmol, 84%), in a similar manner de-
scribed for 10. MS (ESI) m/z 471 (M+H)+. 1H NMR (CDCl3) d 3.0–3.0
(2H, m), 3.5 (3H, s), 3.9 (3H, s), 4.1–4.1 (2H, m), 4.8–4.9 (1H, m), 5.8
(1H, s), 6.3–6.3 (1H, m), 6.4–6.4 (1H, m), 6.8–6.8 (1H, m), 7.0 (1H,
dd, J = 8.1, 1.5 Hz), 7.1–7.1 (1H, m), 7.2 (1H, t, J = 7.9 Hz), 7.2 (2H, br
s), 7.3–7.4 (2H, m). Anal. Calcd for C24H23ClN2O6: C, 61.21; H, 4.92;
N, 5.95. Found: C, 61.15; H, 4.86; N, 5.71.
chloro-6-(2,3-dihydro-1,4-benzodioxin-5-yl)-4H,6H-pyrrolo[1,2-a]
[4,1]benzoxazepin-4-yl]acetate (173 mg, 0.35 mmol), 10% palla-
dium-carbon (wet, 102 mg) was added. The resulting mixture
was stirred for 29 h in a hydrogen atmosphere. The catalyst was fil-
tered off, followed by washing with ethyl acetate sufficiently. The
filtrate was concentrated under reduced pressure to give the title
compound 19C (173 mg, 0.35 mmol, 100%). MS (ESI) m/z 410
(MÀH)+. 1H NMR (CDCl3) d 2.98–3.20 (2H, m), 3.97–4.19 (4H, m),
4.85–4.93 (1H, m), 5.63–5.72 (1H, m), 6.25–6.44 (2H, m), 6.70–
7.03 (3H, m), 7.06–7.24 (2H, m), 7.33–7.45 (2H, m). Anal. Calcd
for C32H43ClN2O7Á0.2 H2OÁ0.2 n-hexane: C, 64.40; H, 4.94; N, 3.24.
Found: C, 64.58; H, 4.62; N, 3.06.
4.1.1.42. 3-({2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-4H,
6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetyl}amino)propi-
onic acid (15f).
Ethyl 3-({2-[(4R,6S)-8-chloro-6-(2,3-dime-
thoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetyl}-
amino)propionate (98 mg, 0.19 mmol, prepared from 8) was trea-
ted by using potassium carbonate (106 mg, 0.76 mmol) to give
the title compound 15f (67.8 mg, 0.14 mmol, 73%), in a similar
manner described for 10. MS (ESI) m/z 485 (M+H)+. 1H NMR (CDCl3)
d 2.6–2.6 (2H, m), 2.9–2.9 (2H, m), 3.4 (3H, s), 3.4–3.5 (1H, m), 3.5–
3.7 (2H, m), 3.8–3.8 (1H, m), 3.9 (3H, s), 4.8 (1H, dd, J = 5.1, 6.6 Hz),
5.8 (1H, s), 6.3–6.4 (2H, m), 6.7–6.8 (1H, m), 7.0 (1H, dd, J = 7.9,
1.6 Hz), 7.1–7.1 (1H, m), 7.2–7.3 (2H, m), 7.3–7.4 (2H, m). Anal.
Calcd for C25H25ClN2O6: C, 61.92; H, 5.20; N, 5.78. Found: C,
61.94; H, 5.23; N, 5.47.
4.1.1.38.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetyl}-4-piperi-
dine carboxylic acid (15b). Ethyl 1-{2-[(4R,6S)-8-chloro-
1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
6-(2,3-dimethoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-
4-yl]acetyl}-4-piperidine carboxylate (66.1 mg, 0.120 mmol,
prepared from 8) was treated by using potassium carbonate
(66.3 mg, 0.480 mmol) to give the title compound 15b (58.7 mg,
0.112 mmol, 93%), in a similar manner described for 10. MS (ESI)
m/z 525 (M+H)+. 1H NMR (CDCl3) d 1.6–1.8 (2H, m), 1.8–2.0 (2H,
m), 2.5–2.6 (1H, m), 2.9 (1H, dd, J = 14.2, 4.6 Hz), 2.9–3.3 (2H, m),
3.4 (3H, s), 3.9 (3H, s), 3.9–4.1 (1H, m), 4.3–4.6 (1H, m), 4.9–5.0
(1H, m), 5.7 (1H, s), 6.2–6.3 (1H, m), 6.3–6.4 (1H, m), 6.7 (1H, d,
J = 8.5 Hz), 6.9 (1H, dd, J = 13.7, 7.6 Hz), 7.1 (1H, dd, J = 2.7,
1.5 Hz), 7.1 (1H, td, J = 7.9, 3.3 Hz), 7.2–7.3 (2H, m), 7.3–7.4 (2H,
m). Anal. Calcd for C28H29ClN2O6: C, 64.06; H, 5.57; N, 5.34. Found:
C, 63.78; H, 5.69; N, 5.21.
4.1.1.43. 3-({2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-4H,
6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetyl}amino)benzoic
acid (15g).
Methyl 3-({2-[(4R,6S)-8-chloro-6-(2,3-dimethoxy
phenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetyl}ami-
no) benzoate (109 mg, 0.20 mmol, prepared from 8) was treated by
using potassium carbonate (111 mg, 0.80 mmol) to give the title
compound 15g (71.8 mg, 0.13 mmol, 67%), in a similar manner de-
scribed for 10. MS (ESI) m/z 533 (M+H)+. 1H NMR (CDCl3) d 3.1 (1H,
m), 3.5 (3H, s), 3.9 (3H, s), 4.9–5.0 (1H, m), 5.9 (1H, s), 6.4 (2H, m),
6.6–7.4 (6H, m), 7.6–8.1 (6H, m), 8.6 (1H, br s). Anal. Calcd for
4.1.1.39. (3S)-1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetyl}-3-piperi-
dine carboxylic acid (15c).
6-(2,3-dimethoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-
4-yl]acetyl}-3-piperidine carboxylate (127 mg, 0.23 mmol,
Ethyl (3S)-1-{2-[(4R,6S)-8-chloro-
C29H25ClN2O6: C, 65.35; H, 4.73; N, 5.26. Found: C, 65.11; H,
prepared from 8) was treated by using potassium carbonate
(127 mg, 0.92 mmol) to give the title compound 15c (78.7 mg,
0.150 mmol, 65%), in a similar manner described for 10. MS (ESI)
m/z 525 (M+H)+. 1H NMR (CDCl3) d 1.4–1.6 (1H, m), 1.6–1.8 (2H,
m), 1.9–2.1 (1H, m), 2.5–2.6 (1H, m), 2.8–3.1 (2H, m), 3.1–3.4 (2H,
m), 3.4 (3H, s), 3.8 (3H, s), 4.0–4.3 (1H, m), 4.6–4.6 (1H, m), 4.9–
5.0 (1H, m), 5.8 (1H, s), 6.2 (1H, br s), 6.4 (1H, t, J = 3.2 Hz), 6.7–
6.7 (1H, m), 6.9–7.0 (1H, m), 7.1 (1H, br s), 7.1–7.2 (1H, m), 7.2–
7.4 (3H, m). Anal. Calcd for C28H29ClN2O6Á0.25H2O: C, 63.51; H,
5.62; N, 5.29. Found: C, 63.62; H, 5.43; N, 5.30.
4.93; N, 5.06.
4.1.1.44. Methyl [(4R,6S)-8-chloro-6-(2,3-dimethoxyphenyl)-4H,
6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetate (24).
pound 7 (12.0 g) was isolated and purified by HPL [CHIRALCEL OD
(Daicel, 50
Com-
u
 500 mm), eluting solvent n-hexane–isopropa-
nol = 50:50, dissolution rate: 50 ml/min], whereby the (4R,6S)-iso-
mer (24, 5.9 g) was obtained from the fraction with a retention
time of 23 min and the (4S,6R)-isomer (5.9 g) was obtained from
the fraction with a retention time of 36 min, respectively.
4.1.1.40.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]acetyl}-1-piperazi-
nyl)acetic acid (15d). Ethyl 2-(4-{2-[(4R,6S)-8-chloro-6-(2,3-
2-(4-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4.1.1.45. 2-[(4R,6S)-8-chloro-6-(2,3-dimethoxyphenyl)-4H,6H-
pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethanol (25).
Com-
pound 24 (5.92 g, 13.8 mmol) was dissolved in tetrahydrofuran
(100 ml). Under ice-cooling, lithium aluminum hydride (856 mg,
20.8 mmol) was added to the resulting mixture and stirred for
3 h. To the solution, water (1 ml), a 15% aqueous sodium hydroxide
solution (1 ml), and water (3 ml) were added successively. The
mixture was stirred for 3 h. MgSO4 was added to dry the mixture.
After filtration through celite, the solvent was distilled off under
reduced pressure to give the title compound 25 (4.80 g, 12.0 mmol,
87%). 1H NMR (CDCl3) d 2.16–2.50 (3H, m), 3.45 (3H, s), 3.86 (3H, s),
dimethoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]
acetyl}-1-piperazinyl)acetate (79 mg, 0.139 mmol, prepared from
8) was treated by using potassium carbonate (77 mg, 0.56 mmol)
to give the title compound 15d (49 mg, 0.09 mmol, 65%), in a sim-
ilar manner described for 10. MS (ESI) m/z 541 (M+H)+. 1H NMR
(CDCl3) d 2.6–2.9 (2H, m), 3.0–3.4 (3H, m), 3.4 (3H, s), 3.6–3.8
(2H, m), 3.8 (3H, s), 4.1–4.4 (3H, m), 4.9–5.0 (1H, m), 5.8 (1H, s),
6.3 (1H, br s), 6.4–6.4 (1H, m), 6.7–6.8 (2H, m), 6.9–7.0 (1H, m),
7.1–7.1 (1H, m), 7.1–7.2 (2H, m), 7.3–7.4 (3H, m). Anal. Calcd for

M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
3083
3.93–3.99 (2H, m), 4.61–4.66 (1H, m), 5.76 (1H, s), 6.31–6.35 (1H,
m), 6.39 (1H, t, J = 3.1 Hz), 6.72–6.75 (1H, m), 6.95 (1H, d,
J = 8.3 Hz), 7.09–7.11 (1H, m), 7.19 (1H, t, J = 7.8 Hz), 7.25–7.28
(1H, m), 7.33–7.39 (2H, m).
m), 4.64–4.56 (1H, m), 5.70 (1H, s), 6.40–6.34 (2H, m), 6.70 (1H, d,
J = 2.0 Hz), 6.95 (1H, dd, J = 8.2, 1.6 Hz), 7.10–7.07 (1H, m), 7.21–
7.15 (1H, m), 7.28–7.31 (2H, m), 7.36–7.34 (2H, m).
4.1.1.50.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]propanoyl}-4-pipe
ridinyl)acetic acid (30a). Compound 29a (86 mg, 0.15 mmol)
2-(1-{3-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4.1.1.46. 2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-4H,6H-
pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethylmethanesulfonate
(26).
Compound 25 (4.79 g, 12.0 mmol) was dissolved in
was treated by using potassium carbonate (82 mg, 0.59 mmol) to
give the title compound 30a (61.2 mg, 0.11 mmol, 73%), in a similar
manner described for 10. 1H NMR (CDCl3) d 1.89–1.04 (4H, m), 2.00
(1H, br), 2.46–2.20 (4H, m), 2.75–2.47 (3H, m), 3.07–2.96 (1H, m),
3.43 (3H, s), 3.98–3.80 (4H, m), 4.44–4.36 (1H, m), 4.66–4.57 (1H,
m), 5.70 (1H, s), 6.40–6.33 (2H, m), 6.72–6.69 (1H, m), 6.98–6.93
(1H, m), 7.11–7.07 (1H, m), 7.21–7.15 (1H, m), 7.39–7.25 (3H,
m). Anal. Calcd for C30H33ClN2O: C, 65.15; H, 6.01; N, 5.07. Found:
C, 65.36; H, 6.20; N, 4.80.
dichloromethane (60 ml). Under ice-cooling, triethylamine
(2.51 ml, 18.0 mmol) and methanesulfonic acid chloride (1.11 ml,
14.4 mmol) were added. The resulting mixture was stirred for 3 h
and diluted with dichloromethane and washed with water and
satd NaHCO3 aq. The organic layer was dried over Na2SO4. The sol-
vent was distilled off under reduced pressure to give the title com-
pound 26 (5.77 g, 12.0 mmol, quant.). 1H NMR (CDCl3) d 2.41–2.57
(2H, m), 2.98 (3H, s), 3.43 (3H, s), 3.85 (3H, s), 4.48–4.62 (3H, m),
5.73 (1H, s), 6.32–6.29 (1H, m), 6.39 (1H, t, J = 3.2 Hz), 6.72 (1H,
d, J = 2.2 Hz), 6.96 (1H, dd, J = 8.1, 1.46 Hz), 7.11 (1H, q,
J = 1.5 Hz), 7.20 (1H, t, J = 8.1 Hz), 7.25–7.31 (1H, m), 7.33–7.41
(2H, m).
4.1.1.51. Ethyl (3S)-1-(3-((4R,6S)-8-chloro-6-(2,3-dimethoxy-
phenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl)propa-
noyl)-3-piperidine carboxylate (29b).
Compound 29a (1.00
g, 2.34 mmol) was treated by using (S)-(+)-ethylnipecotate
(440 mg, 2.80 mmol) to give the title compound 29b (1.21 g,
2.13 mmol, 91%), in a similar manner described for 9. MS (ESI)
m/z 567 (M+H)+. 1H NMR (CDCl3) d 1.21–1.28 (3H, m), 1.38–1.49
(1H, m), 1.63–1.81 (2H, m), 1.99–2.09 (1H, m), 2.36–2.46 (3H,
m), 2.52–2.84 (2H, m), 2.98–3.06 (1H, m), 3.43 (3H, s), 3.80–3.87
(4H, m), 4.09–4.18 (2H, m), 4.38–4.42 (1H, m), 5.70 (1H, s), 6.34–
6.39 (2H, m), 6.70–6.72 (1H, m), 6.94 (1H, d, J = 8.1 Hz), 7.08 (1H,
dd, J = 2.7, 1.5 Hz), 7.17 (1H, t, J = 8.0 Hz), 7.26–7.36 (3H, m).
4.1.1.47.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]propionitrile
(27). Compound 26 (5.77 g, 12.0 mmol) was dissolved in
3-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
dimethylsulfoxide (60 ml). To the solution, sodium cyanide
(1.21 g, 24.0 mmol) was added. The resulting mixture was stirred
at 50 °C for 13 h. After the reaction mixture was allowed to warm
to room temparature, water and ethyl acetate were added. The or-
ganic layer was separated and washed with brine, and dried over
Na2SO4, and then concentrated in vacuo. The residue was purified
by silica gel column chromatography (n-hexane–ethyl acetate) to
give the title compound 27 (4.51 g, 11.0 mmol, 92%). 1H NMR
(CDCl3) d 2.48–2.30 (2H, m), 2.68 (2H, t, J = 7.3 Hz), 3.43 (3H, s),
3.86 (3H, s), 4.49 (1H, dd, J = 9.3, 3.9 Hz), 5.73 (1H, s), 6.27–6.30
(1H, m), 6.39 (1H, t, J = 3.2 Hz), 6.72–6.74 (1H, m), 6.96 (1H, d,
J = 8.1 Hz), 7.10–7.13 (1H, m), 7.17–7.23 (1H, m), 7.25–7.29 (1H,
m), 7.33–7.41 (2H, m).
4.1.1.52. (3S)-1-(3-((4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl)propanoyl)-3-pipe
ridine carboxylic acid (30b).
Compound 29b (100 mg,
0.18 mmol) was treated by using potassium carbonate (49 mg,
0.35 mmol) to give the title compound 30b (85 mg, 0.16 mmol,
89%), in a similar manner described for 10.
MS (ESI) m/z 539 (M+H)+. 1H NMR (CDCl3) d 1.25–1.32 (1H, m),
1.41–1.53 (1H, m), 1.65–1.87 (2H, m), 1.99–2.13 (1H, m), 2.37–2.78
(4H, m), 2.91–3.15 (2H, m), 3.43 (3H, s), 3.76–4.03 (5H, m), 4.37–
4.42 (1H, m), 5.71 (1H, s), 6.34–6.39 (2H, m), 6.70–6.72 (1H, m),
6.94 (1H, d, J = 7.8 Hz), 7.07–7.10 (1H, m), 7.17 (1H, t, J = 8.0 Hz),
7.27–7.36 (6H, m). Anal. Calcd for C29H31ClN2O6Á0.25H2O: C,
64.08; H, 5.84; N, 5.15. Found: C, 64.22; H, 5.98; N, 4.82.
4.1.1.48. 3-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-4H,6H-
pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]propionic
acid
(28). Compound 27 (4.51 g, 11.0 mmol) was dissolved in 2-
propanol (50 ml). A 5 N aqueous sodium hydroxide solution
(50 ml) was added and the resulting mixture was heated under re-
flux for 4 days. The reaction mixture was concentrated in vacuo.
Under ice-cooling, 1 N hydrochloric acid was added to make the
residue acidic, followed by extraction with ethyl acetate. The ex-
tract was washed with brine and dried over Na2SO4, and then con-
centrated in vacuo. The residue was purified by silica gel column
chromatography (chloroform–methanol) to give the title com-
pound 28 (4.56 g, 10.7 mmol, 97%). 1H NMR (CDCl3) d 1.55 (1H,
br s), 2.80–2.30 (4H, m), 3.43 (3H, s), 3.85 (3H, s), 4.41 (1H, q,
J = 4.5 Hz), 5.72 (1H, s), 6.35–6.32 (1H, m), 6.38 (1H, t, J = 3.2 Hz),
6.71 (1H, d, J = 2.2 Hz), 6.94 (1H, dd, J = 8.3, 1.5 Hz), 7.09–7.10
(1H, m), 7.18 (1H, t, J = 7.9 Hz), 7.25–7.39 (3H, m). Anal. Calcd for
4.1.1.53. Methyl 1-(3-((4R,6S)-8-chloro-6-(2,3-dimethoxyphe
nyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl)propanoyl)-3-
azetidine carboxylate (29c).
Compound 28 (58 mg, 0.14
mmol) was treated by using 3-methylazetidine hydrochloride
(27 mg, 0.16 mmol) to give the title compound 29c (51 mg,
0.10 mmol, 72%), in a similar manner described for 9. MS (ESI) m/
z 525 (M+H)+. 1H NMR (CDCl3) d 2.28–2.48 (4H, m), 3.24–3.47
(4H, m), 3.75 (3H, s), 3.85 (3H, s), 4.06–4.34 (4H, m), 4.36–4.40
(1H, m), 5.70 (1H, s), 6.32–6.34 (1H, m), 6.37 (1H, t, J = 3.2 Hz),
6.71 (1H, d, J = 2.0 Hz), 6.95 (1H, d, J = 8.1 Hz), 7.08 (1H, dd,
J = 2.7, 1.5 Hz), 7.19 (1H, t, J = 8.1 Hz), 7.26–7.41 (3H, m).
C
23H22ClNO5Á0.5 2-propanol: C, 64.26; H, 5.72; N, 3.06. Found: C,
64.30; H, 5.70; N, 3.02.
4.1.1.54.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl)propanoyl)-3-azeti
dine carboxylic acid (30c). Compound 29c (51 mg, 0.10
1-(3-((4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4.1.1.49.
2-(1-{3-[(4R,6S)-8-chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]propanoyl}-4-pipe
ridinyl)acetate (29a).
Compound 28 (1.04 g, 2.43 mmol) was
mmol) was treated by using potassium carbonate (40 mg,
0.29 mmol) to give the title compound 30c (47 mg, 0.09 mmol,
95%), in a similar manner described for 10. MS (ESI) m/z 512
(M+H)+. 1H NMR (CDCl3) d 2.09–2.34 (4H, m), 3.02–3.13 (1H, m),
3.29–3.44 (4H, m), 3.78 (3H, s), 3.87–4.05 (2H, m), 4.10–4.19
(1H, m), 4.26–4.33 (1H, m), 5.64 (1H, s), 6.24–6.30 (1H, m), 6.65–
6.70 (1H, m), 6.83–6.90 (1H, m), 6.96–7.02 (1H, m), 7.09–7.15
treated by using ethyl piperidine-4-acetate (500 mg, 2.92 mmol) to
give the title compound 29a (1.32 g, 2.27 mmol, 93%), in a similar
manner described for 9. 1H NMR (CDCl3) d 1.11 (2H, br s), 1.26 (3H,
t, J = 7.1 Hz), 1.50–1.53 (1H, m), 1.69–1.80 (2H, m), 2.00 (1H, br s),
2.19–2.26 (2H, m), 2.36–2.43 (2H, m), 2.55–2.61 (2H, m), 3.01 (1H,
s), 3.43 (3H, s), 3.85 (3H, s), 4.13 (2H, q, J = 7.2 Hz), 4.42–4.37 (1H,

3084
M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
(1H, m), 7.22–7.30 (3H, m). Anal. Calcd for C27H28ClN2
O6Á0.25H2OÁ0.75CHCl3: C, 54.93; H, 4.98; N, 4.62. Found: C,
54.89; H, 5.06; N, 4.59.
2.65–2.32 (5H, m), 2.94–3.18 (2H, m), 3.49–3.59 (1H, m), 3.71
(3H, s), 3.83 (3H, s), 3.97–4.14 (3H, m), 4.36–4.40 (1H, m), 5.69
(1H, s), 6.32–6.36 (2H, m), 6.69 (1H, s), 6.91–6.95 (1H, m), 7.05–
7.08 (1H, m), 7.16 (1H, t, J = 8.1 Hz), 7.27–7.30 (1H, m), 7.32–7.35
4.1.1.55. Ethyl 2-(3-azetidinyl)acetate hydrochloride.
To a
(2H, m). Anal. Calcd for
58.87; H, 5.80; N, 4.54. Found: C, 58.73; H, 5.65; N, 4.48.
C
30H33ClN2O7Á1.0H2OÁ0.25CHCl3: C,
solution of ethyl 2-(1-benzhydryl-3-azetidinylidene)acetate
(1.41 g, 3.00 mmol) in ethanol (15.0 ml), 1 N hydrochloric acid
(3.6 ml) and 10% palladium-carbon (1.5 g) were added, followed
by catalytic hydrogenation at 5 atm for 14 h. The catalyst was fil-
tered out and the filtrate was concentrated in vacuo. The residue
was dissolved in ethanol (10 ml) to obtain the title compound as
a 0.3 M ethanol solution.
4.1.1.60. Methyl 3-[(1-{3-[(4R,6S)-8-chloro-6-(2,3-dimethoxy-
phenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]propa-
noyl}-4-piperidinyl)oxy]propanoate (29f).
Compound 29e
(116 mg, 0.20 mmol) was treated by using methyl 3-(4-piperidi-
nyloxy)propanoate20 (41 mg, 0.22 mmol) to give the title com-
pound 29f (110 mg, 0.18 mmol, 92%), in
a similar manner
4.1.1.56. Ethyl
phenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]propa-
no yl)-3-azetidinyl)acetate (29d). Compound 28 (86 mg,
2-(1-(3-[(4R,6S)-8-chloro-6-(2,3-dimethoxy-
described for 9. MS (ESI) m/z 597 (M+H)+. 1H NMR (CDCl3) d
1.05–1.21 (1H, m), 1.49–1.60 (1H, m), 1.70–1.90 (2H, m), 2.35–
2.43 (2H, m), 2.51–2.72 (4H, m), 3.21–3.41 (2H, m), 3.43 (3H, s),
3.50–3.57 (1H, m), 3.60–4.08 (11H, m), 4.37–4.42 (1H, m), 5.70
(1H, s), 6.34–6.39 (2H, m), 6.70 (1H, d, J = 1.7 Hz), 6.95 (1H, dd,
J = 8.2, 1.5 Hz), 7.08 (1H, dd, J = 2.9, 1.7 Hz), 7.18 (1H, t,
J = 8.2 Hz), 7.27–7.32 (1H, m), 7.34–7.35 (2H, m).
0.20 mmol) was treated by using the 0.3 M ethanol solution
(1.30 ml, 0.40 mmol) of ethyl 2-(3-azetidinyl)acetate hydrochlo-
ride to give the title compound 29d (109 mg, 0.20 mmol, 96%), in
a similar manner described for 9.
MS (ESI) m/z 553 (M+H)+.
1H NMR (CDCl3) d 1.22–1.27 (3H, m), 2.29–2.44 (4H, m), 2.51–
2.54 (1H, m), 2.60 (1H, dd, J = 7.8, 3.4 Hz), 2.82–2.97 (1H, m),
3.42 (3H, s), 3.60–3.66 (1H, m), 3.73–3.81 (1H, m), 3.84 (3H, s),
4.08–4.16 (3H, m), 4.26 (1H, t, J = 8.5 Hz), 4.36–4.40 (1H, m),
5.69–5.71 (1H, m), 6.32–6.34 (1H, m), 6.37 (1H, t, J = 3.2 Hz),
6.70–6.72 (1H, m), 6.94 (1H, dd, J = 8.3, 1.5 Hz), 7.06–7.09 (1H,
m), 7.16–7.20 (2H, m), 7.26–7.35 (2H, m)
4.1.1.61. 3-[(1-{3-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]propanoyl}-4-pipe
ridinyl)oxy]propanoic acid (30f).
Compound 29f (110 mg,
0.18 mmol) was treated by using potassium carbonate (76 mg,
0.55 mmol) to give the title compound 30f (66 mg, 0.11 mmol,
61%), in a similar manner described for 10. MS (ESI) m/z 583
(M+H)+. 1H NMR (CDCl3) d 1.51–1.59 (2H, m), 1.75–1.84 (2H, m),
2.35–2.42 (2H, m), 2.51–2.72 (4H, m), 3.21–3.38 (2H, m), 3.43
(3H, s), 3.53–3.58 (1H, m), 3.64–3.75 (3H, m), 3.83–3.89 (4H, m),
4.36–4.42 (1H, m), 5.70–5.71 (1H, m), 6.34–6.38 (2H, m), 6.70–
6.71 (1H, m), 6.95 (1H, dd, J = 8.2, 1.3 Hz), 7.07–7.09 (1H, m),
7.18 (1H, t, J = 8.0 Hz), 7.28–7.35 (3H, m). Anal. Calcd for
4.1.1.57.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]propanoyl)-3-aze-
tidinyl)acetic acid (30d). Compound 29d (109 mg,
2-(1-(3-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
0.20 mmol) was treated by using potassium carbonate (82 mg,
0.59 mmol) to give the title compound 30d (88 mg, 0.17 mmol,
85%), in a similar manner described for 10. MS (ESI) m/z 525
(M+H)+. 1H NMR (CDCl3) d 2.28–2.42 (4H, m), 2.53 (1H, d,
J = 7.4 Hz), 2.61 (1H, d, J = 7.4 Hz), 2.80–2.94 (1H, m), 3.42 (3H, s),
3.59–3.68 (1H, m), 3.73–3.79 (1H, m), 3.84 (3H, s), 4.07–4.14
(1H, m), 4.25 (1H, t, J = 8.6 Hz), 4.34–4.39 (1H, m), 5.69 (1H, s),
6.31–6.34 (1H, m), 6.37 (1H, t, J = 3.2 Hz), 6.69–6.72 (1H, m),
6.92–6.96 (1H, m), 7.06–7.09 (1H, m), 7.18 (1H, t, J = 7.8 Hz),
7.27–7.30 (1H, m), 7.34–7.36 (2H, m). Anal. Calcd for
C
31H35ClN2O7Á1.25H2O: C, 61.48; H, 6.24; N, 4.63. Found: C,
61.44; H, 5.93; N, 4.48.
4.1.1.62. Methyl
2-[(1-{3-[(4R,6S)-8-chloro-6-(2,3-dimetho-
xyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]propa-
noyl}-4-piperidinyl)methoxy]acetate (29g).
Compound 28
(86 mg, 0.20 mmol) was treated by using methyl 2-(4-piperidinyl-
methoxy)acetate21 (56 mg, 0.30 mmol) to give the title compound
29g (117 mg, 0.196 mmol, 97%), in a similar manner described for
9. MS (ESI) m/z 597 (M+H)+. 1H NMR (CDCl3) d 1.05–1.20 (2H, m),
1.70–1.91 (3H, m), 2.35–2.43 (2H, m), 2.50–2.73 (3H, m), 2.95–
3.04 (1H, m), 3.32–3.40 (2H, m), 3.43 (3H, s), 3.75 (3H, s), 3.84–
3.97 (4H, m), 4.07 (2H, s), 4.37–4.42 (1H, m), 4.57–4.65 (1H, m),
5.70 (1H, s), 6.34–6.39 (2H, m), 6.69–6.71 (1H, m), 6.95 (1H, dd,
J = 8.3, 1.5 Hz), 7.08 (1H, dd, J = 2.7, 1.5 Hz), 7.18 (1H, t,
J = 7.9 Hz), 7.29 (1H, dd, J = 7.9, 1.0 Hz), 7.33–7.36 (2H, m).
C
28H29ClN2O6Á0.75H2OÁ0.25CHCl3: C, 59.67; H, 5.50; N, 4.93.Found:
C, 59.69; H, 5.57; N, 4.74.
4.1.1.58. Methyl 2-[(1-{3-[(4R,6S)-8-chloro-6-(2,3-dimethoxy-
phenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]propanoyl}-
4-piperidinyl)oxy]acetate (29e).
Compound 28 (86 mg,
0.20 mmol) was treated by using methyl 2-(4-piperidinyloxy)ace-
tate19 (52 mg, 0.30 mmol) to give the title compound 29e
(116 mg, 0.20 mmol, 99%), in a similar manner described for 9.
MS (ESI) m/z 583 (M+H)+. 1H NMR (CDCl3) d 1.53–1.90 (4H, m),
2.35–2.43 (2H, m), 2.52–2.60 (1H, m), 2.65–2.74 (1H, m), 3.20–
3.35 (2H, m), 3.43 (3H, s), 3.59–3.65 (1H, m), 3.68–3.78 (4H, m),
3.84–4.03 (4H, m), 4.10–4.15 (3H, m), 4.37–4.43 (1H, m), 5.69–
5.72 (1H, m), 6.34–6.39 (2H, m), 6.70 (1H, s), 6.95 (1H, dd, J = 8.3,
1.5 Hz), 7.08 (1H, dd, J = 2.7, 1.5 Hz), 7.18 (1H, td, J = 8.0, 2.1 Hz),
7.26–7.32 (1H, m), 7.33–7.37 (2H, m).
4.1.1.63. 2-[(1-{3-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]propanoyl}-4-pipe
ridinyl)methoxy]acetic acid (30g).
Compound 29g (117 mg,
0.20 mmol) was treated by using potassium carbonate (81 mg,
0.59 mmol) to give the title compound 30g (110 mg, 0.19 mmol,
96%), in a similar manner described for 10. MS (ESI) m/z 583
(M+H)+. 1H NMR (CDCl3) d 1.18–1.01 (2H, m), 1.70–1.91 (3H, m),
2.35–2.43 (2H, m), 2.50–2.73 (3H, m), 3.04–2.93 (1H, m), 3.38–
3.30 (2H, m), 3.42 (3H, s), 3.82–4.03 (6H, m), 4.35–4.42 (1H, m),
4.54–4.63 (1H, m), 5.69 (1H, s), 6.33–6.39 (2H, m), 6.69–6.71
(1H, m), 6.92–6.96 (1H, m), 7.06–7.09 (1H, m), 7.16 (1H, t,
J = 7.8 Hz), 7.28–7.30 (1H, m), 7.33–7.36 (2H, m). Anal. Calcd for
4.1.1.59. 2-[(1-{3-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]propanoyl}-4-pipe
ridinyl)oxy]acetic acid (30e).
Compound 29e (116 mg,
0.20 mmol) was treated by using potassium carbonate (90 mg,
0.65 mmol) to give the title compound 30e (110 mg, 0.19 mmol,
97%), in a similar manner described for 10. MS (ESI) m/z 569
(M+H)+. 1H NMR (CDCl3) d 1.42–1.56 (2H, m), 1.78–1.91 (2H, m),
C
31H35ClN2O7Á0.75H2OÁ0.25CHCl3: C, 59.89; H, 5.95; N, 4.47.
Found: C, 59.78; H, 5.84; N, 4.40.

M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
3085
4.1.1.64. 4-(tert-Butyl) 2-methyl 2,4-morpholine dicarboxyl-
ate. To a solution of 4-(tert-butoxycarbonyl)-2-morpholine
3.36–3.46 (5H, m), 3.80–3.89 (5H, m), 4.10–4.30 (4H, m), 4.35–
4.44 (1H, m), 5.70 (1H, s), 6.31–6.40 (2H, m), 6.71 (1H, s), 6.91–
6.98 (1H, m), 7.08 (1H, s), 7.19–7.38 (4H, m). Anal. Calcd for
dicarboxylic acid (231 mg, 1.00 mmol) in dimethylformamide
(2.0 ml), methyl iodide (0.125 ml, 1.33 mmol) and potassium car-
bonate (152 mg, 1.10 mmol) were added. The resulting mixture
was stirred at room temperature for 24 h. To the reaction mixture,
a 10% aqueous citric acid solution was added. The resulting mix-
ture was diluted with ethyl acetate. After the organic layer was
dried over Na2SO4, the solvent was distilled off to give the title
compound (232 mg, 0.95 mmol, 95%). MS (ESI) m/z 246 (M+H)+.
1H NMR (CDCl3) d 1.47 (9H, s), 3.02–3.18 (2H, m), 3.58 (1H, td,
J = 11.1, 2.6 Hz), 3.74–3.80 (4H, m), 3.98–4.14 (3H, m).
C
29H30ClN3O7Á0.1H2OÁ0.6CHCl3: C, 55.92; H, 4.79; N, 6.48. Found:
C, 56.17; H, 5.03; N, 6.12.
4.1.1.70. (4R,6S)-4-(2-Azidoethyl)-8-chloro-6-(2,3-dimethoxy-
phenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepine (31).
To a
N,N-dimethylformamide–H2O (10:1, 22 ml) mixed solution of
compound 26 (891 mg, 1.86 mmol), sodium azide (727 mg,
11.2 mmol) was added. The resulting mixture was stirred at
80 °C overnight. The reaction mixture was concentrated in vacuo.
The residue was dissolved in ethyl acetate and washed with water.
The organic layer was dried over Na2SO4, and then concentrated
under reduced pressure. The residue was purified by silica gel col-
umn chromatography (ethyl acetate–n-hexane = 1:4) to give the ti-
tle compound 31 (780 mg, 1.84 mmol, 99%). 1H NMR (CDCl3) d
2.20–2.29 (1H, m), 2.33–2.43 (1H, m), 3.43 (3H, s), 3.52–3.68
(2H, m), 3.85 (3H, s), 4.48–4.53 (1H, m), 5.72 (1H, s), 6.29–6.31
(1H, m), 6.37–6.40 (1H, m), 6.72–6.74 (1H, m), 6.93–6.97 (1H,
m), 7.10–7.12 (1H, m), 7.17–7.23 (1H, m), 7.27–7.31 (2H, m),
7.40–7.33 (2H, m).
4.1.1.65. Methyl 2-morpholine carboxylate hydrochlo-
ride.
To a solution of 4-(tert-butyl) 2-methyl 2,4-morpholine
dicarboxylate (232 mg, 0.95 mmol) in dioxane (1.0 ml), 4 N hydro-
chloric acid in dioxane (1.18 ml) was added. The resulting mixture
was stirred at room temperature for 15 h. The solvent was distilled
off under reduced pressure to give the title compound (232 mg,
0.95 mmol, quant.). 1H NMR (CDCl3) d 3.03–3.19 (2H, m), 3.26–
3.45 (2H, m), 3.55–3.69 (1H, m), 3.82 (3H, s), 4.03–4.22 (2H, m),
4.58–4.69 (1H, m).
4.1.1.66. Methyl
phenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]propa-
noyl}-2-morpholine carboxylate (29h). Compound 28
(86 mg, 0.20 mmol) was treated by using methyl 2-morpholine
carboxylate hydrochloride (44 mg, 0.24 mmol) to give the title
compound 29h (119 mg, 0.20 mmol, quant.), in a similar manner
described for 9. MS (ESI) m/z 555 (M+H)+. 1H NMR (CDCl3) d
2.31–4.64 (21H, m), 5.70–5.74 (1H, m), 6.33–6.42 (2H, m), 6.70–
6.75 (1H, m), 6.94–7.41 (6H, m).
4-{3-[(4R,6S)-8-chloro-6-(2,3-dimethoxy-
4.1.1.71. Ethyl 1-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3-
triazol-4-carboxylate (32a) and ethyl 1-{2-[(4R,6S)-8-chloro-6-
(2,3-dimethoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxaze-
pin-4-yl]ethyl}-1H-1,2,3-triazol-5-carboxylate.
To a solu-
tion of compound 31 (180 mg, 0.42 mmol) in toluene (5 ml),
ethyl propiolate (0.094 ml, 0.93 mmol) was added. Then, the mix-
ture was heated under reflux overnight. After the reaction mixture
was concentrated in vacuo, the residue was purified by preparative
TLC (methanol–chloroform = 1:100) to give the title compounds, 4-
isomer 32a (140 mg, 0.27 mmol, 64%) and 5-isomer (61.4 mg,
0.12 mmol, 30%). 4-isomer 32a (high polarity fraction): MS (ESI)
m/z 523 (M+H)+. 1H NMR (CDCl3) d 1.39 (3H, t, J = 7.2 Hz), 2.62–
2.74 (2H, m), 3.44 (3H, s), 3.86 (3H, s), 4.38–4.43 (3H, m), 4.70–
4.76 (2H, m), 5.76 (1H, s), 6.30–6.31 (1H, m), 6.38 (1H, t,
J = 3.3 Hz), 6.74 (1H, d, J = 2.2 Hz), 6.96–6.99 (1H, m), 7.10–7.11
(1H, m), 7.21 (1H, t, J = 7.9 Hz), 7.27–7.29 (1H, m), 7.33–7.39 (2H,
m), 8.10 (1H, s). 5-Isomer (low polarity fraction): MS (ESI) m/z
523 (M+H)+. 1H NMR (CDCl3) d 1.36 (3H, t, J = 7.1 Hz), 2.57–2.74
(2H, m), 3.44 (3H, s), 3.86 (3H, s), 4.35 (2H, q, J = 7.1 Hz), 4.44–
4.47 (1H, m), 5.03 (2H, t, J = 7.4 Hz), 5.74 (1H, s), 6.35–6.39 (2H,
m), 6.73 (1H, d, J = 2.2 Hz), 6.96 (1H, dd, J = 7.9, 1.5 Hz), 7.09–7.10
(1H, m), 7.21 (1H, t, J = 7.9 Hz), 7.32–7.41 (3H, m), 8.10 (1H, s).
4.1.1.67.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]propanoyl}-2-mor
pholine carboxylic acid (30h). Compound 29h (154 mg,
4-{3-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
0.28 mmol) was treated by using potassium carbonate (115 mg,
0.83 mmol) to give the title compound 30h (70 mg, 0.13 mmol,
47%), in a similar manner described for 10. MS (ESI) m/z 541
(M+H)+. 1H NMR (CDCl3) d 2.37–2.46 (2H, m), 2.55–2.79 (2H, m),
3.43 (3H, s), 3.56–3.72 (1H, m), 3.81–3.88 (4H, m), 3.99–4.22
(4H, m), 4.39–4.44 (1H, m), 5.71 (1H, s), 6.34–6.40 (2H, m), 6.69–
6.74 (1H, m), 6.93–6.97 (1H, m), 7.08–7.11 (1H, m), 7.13–7.22
(1H, m), 7.27–7.32 (1H, m), 7.34–7.41 (2H, m). Anal. Calcd for
C
28H29ClN2O7Á1.25H2OÁ0.25 diisopropyl ether: C, 60.15; H, 5.99;
N, 4.76. Found: C, 60.14; H, 5.75; N, 4.57.
4.1.1.68. Ethyl
2-(4-{3-[(4R,6S)-8-chloro-6-(2,3-dimethoxy-
4.1.1.72.
6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3-tria-
zole-4-carboxylic acid (33a). Compound 32a (48.7 mg,
1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-4H,
phenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]propanoyl}-
2-oxo-1-piperazinyl)acetate (29i).
Compound 28 (100 mg,
0.23 mmol) was treated by using ethyl 2-oxopiperazineacetate22
hydrochloride (62 mg, 0.28 mmol) to give the title compound 29i
(100 mg, 0.17 mmol, 72%), in a similar manner described for 9.
MS (EI) m/z 595 M+. 1H NMR (CDCl3) d 1.28 (3H, t, J = 7.2 Hz),
2.37–2.47 (2H, m), 2.52–2.73 (2H, m), 3.39–3.44 (5H, m), 3.75–
3.92 (5H, m), 4.11–4.30 (6H, m), 4.41 (1H, t, J = 6.3 Hz), 5.71 (1H,
s), 6.33–6.40 (2H, m), 6.71 (1H, s), 6.95 (1H, d, J = 7.1 Hz), 7.09
(1H, s), 7.15–7.39 (4H, m).
0.093 mmol) was treated by using potassium carbonate (38.6 mg,
0.279 mmol) to give the title compound 33a (41.5 mg, 0.084 mmol,
90%), in a similar manner described for 10. MS (ESI) m/z 495
(M+H)+. 1H NMR (CDCl3) d 2.30–2.42 (2H, m), 3.32 (3H, s), 3.77
(3H, s), 4.16–4.40 (3H, m), 5.61 (1H, s), 6.18–6.20 (2H, m), 6.64–
6.66 (1H, m), 6.82–6.84 (1H, m), 6.92–6.95 (1H, m), 7.05–7.09
(1H, m), 7.18–7.24 (3H, m), 7.91–7.94 (1H, m). Anal. Calcd for
C25H23N4O5ClÁ2H2OÁ0.5CHCl3: C, 51.81; H, 4.77; N, 9.48. Found: C,
51.46; H, 4.38; N, 9.26.
4.1.1.69.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]propanoyl}-2-oxo-
1-piperazinyl)acetic acid (30i). Compound 29i (94 mg,
2-(4-{3-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4.1.1.73. (1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-4H,
6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3-tria-
0.16 mmol) was treated by using potassium carbonate (65 mg,
0.47 mmol) to give the title compound 30i (80 mg, 0.14 mmol,
78%), in a similar manner described for 10. MS (FAB) m/z 568
(M+H)+. 1H NMR (CDCl3) d 2.35–2.46 (2H, m), 2.51–2.76 (2H, m),
zol-4-yl)methanol.
Compound 33a (91.3 mg, 0.175 mmol)
was treated by using lithium aluminum hydride (19.9 mg,
0.524 mmol) to give the title compound (86.8 mg, 0.175 mmol,
quant.), in a similar manner described for 25. MS (ESI) m/z 481

3086
M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
(M+H)+. 1H NMR (CDCl3) d 2.57–2.74 (2H, m), 3.44 (3H, s), 3.87 (3H,
s), 4.39–4.41 (1H, m), 4.62–4.73 (2H, m), 4.76 (2H, d, J = 6.1 Hz),
5.76 (1H, s), 6.29–6.31 (1H, m), 6.38 (1H, t, J = 3.2 Hz), 6.73 (1H,
d, J = 2.2 Hz), 6.97 (1H, dd, J = 8.1, 1.5 Hz), 7.10–7.11 (1H, m), 7.21
(1H, t, J = 8.1 Hz), 7.29–7.31 (1H, m), 7.33–7.35 (1H, m), 7.35–
7.39 (1H, m), 7.55 (1H, s).
6.30–6.31 (1H, m), 6.39 (1H, t, J = 3.3 Hz), 6.75 (1H, d, J = 2.2 Hz),
6.98 (1H, dd, J = 7.9, 1.6 Hz), 7.11–7.12 (1H, m), 7.22 (1H, t,
J = 7.9 Hz), 7.27 (1H, dd, J = 7.9, 1.3 Hz), 7.34–7.40 (2H, m), 7.66
(1H, s).
4.1.1.78.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3-tria
zol-5-yl)acetic acid (33c). 2-(1-{2-[(4R,6S)-8-Chloro-6-(2,3-
2-(1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4.1.1.74.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3-tri
azol-4-yl)acetonitrile. (1-{2-[(4R,6S)-8-Chloro-6-(2,3-dime-
2-(1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
dimethoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-
yl]ethyl}-1H-1,2,3-triazol-5-yl)acetonitrile (20.2 mg, 0.041 mmol)
was treated by using 5 M aqueous sodium hydroxide solution
(1 ml) to give the title compound 33c (15.1 mg, 0.030 mmol, 73%),
in a similar manner described for 28. MS (ESI) m/z 509 (M+H)+. 1H
NMR (CDCl3) d 2.41–2.54 (2H, m), 3.33 (3H, s), 3.40–3.43 (2H, m),
3.75 (3H, s), 4.32–4.45 (3H, m), 5.66 (1H, s), 6.22–6.24 (2H, m),
6.65–6.67 (1H, m), 6.83–6.84 (1H, m), 6.95–6.98 (1H, m), 7.08–
7.11 (1H, m), 7.20–7.23 (2H, m), 7.27–7.29 (1H, m), 7.36–7.38
(1H, m). Anal. Calcd for C26H25N4O5ClÁ3H2OÁ0.4CHCl3: C, 51.88; H,
5.24; N, 9.17. Found: C, 51.60; H, 5.23; N, 8.77.
thoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-
1H-1,2,3-triazol-4-yl)methanol (86.8 mg, 0.180 mmol) was treated
by using methanesulfonyl chloride (0.021 ml, 0.271 mmol) to give
the methanesulfonate (123.0 mg, 0.180 mmol, quant.). Then the
methanesulfonate was treated by sodium cyanide (21.6 mg,
0.440 mmol) to give the title compound (67.0 mg, 0.137 mmol,
76%), in a similar manner described for 26 and 27. MS (ESI) m/z
491 (M+H)+. 1H NMR (CDCl3) d 2.58–2.75 (2H, m), 3.44 (3H, s),
3.83 (2H, s), 3.87 (3H, s), 4.40 (1H, dd, J = 9.3, 3.9 Hz), 4.63–4.76
(2H, m), 5.76 (1H, s), 6.30–6.31 (1H, m), 6.39 (1H, t, J = 3.3 Hz),
6.74 (1H, d, J = 2.2 Hz), 6.98 (1H, dd, J = 7.9, 1.5 Hz), 7.11–7.12
(1H, m), 7.22 (1H, t, J = 7.9 Hz), 7.28 (1H, dd, J = 7.9, 1.5 Hz),
7.33–7.40 (2H, m), 7.62 (1H, s).
4.1.1.79. Ethyl
2-[(1-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxy-
phenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-
1,2,3-triazol-4-yl)methoxy]acetate (32d) and ethyl 2-[(1-{2-
[(4R,6S)-8-chloro-6-(2,3-dimethoxyphenyl)-4H,6H-pyrrolo[1,2-
a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3-triazol-5-yl)methoxy]-
4.1.1.75.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3-tri
azol-4-yl)acetic acid (33b). 2-(1-{2-[(4R,6S)-8-Chloro-6-
2-(1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
acetate.
Compound 31 (151 mg, 0.355 mmol) was treated by
using ethyl 2-(2-propynyloxy)acetate (151 mg, 1.06 mmol) to give
the title compounds, 4-isomer 32d (69.7 mg, 0.123 mmol, 35%) and
5-isomer (50.0 mg, 0.088 mmol, 24%), in a similar manner de-
scribed for 32a. 4-Isomer (low polarity fraction): MS (ESI) m/z
567 (M+H)+. 1H NMR (CDCl3) d 1.28 (3H, t, J = 7.2 Hz), 2.63–2.68
(2H, m), 3.44 (3H, s), 3.86 (3H, s), 4.12 (2H, s), 4.21 (2H, q,
J = 7.2 Hz), 4.38–4.42 (1H, m), 4.64–4.70 (2H, m), 4.72 (2H, s),
5.76 (1H, s), 6.30–6.31 (1H, m), 6.37–6.39 (1H, m), 6.74 (1H, d,
J = 2.2 Hz), 6.97 (1H, dd, J = 8.1, 1.5 Hz), 7.10–7.11 (1H, m), 7.22
(1H, t, J = 8.1 Hz), 7.29–7.39 (3H, m), 7.65 (1H, s). 5-Isomer (high
polarity fraction): MS (ESI) m/z 567 (M+H)+. 1H NMR (CDCl3) d
1.25 (3H, t, J = 7.2 Hz), 2.63–2.78 (2H, m), 3.43 (3H, s), 3.86 (3H,
s), 4.01 (2H, s), 4.17 (2H, q, J = 7.2 Hz), 4.46–4.49 (1H, m), 4.64–
4.79 (4H, m), 5.74 (1H, s), 6.32–6.34 (1H, m), 6.37–6.38 (1H, m),
6.73 (1H, d, J = 2.0 Hz), 6.96 (1H, dd, J = 8.2, 1.3 Hz), 7.09–7.10
(1H, m), 7.19 (1H, t, J = 8.2 Hz), 7.32–7.38 (3H, m), 7.61 (1H,s).
(2,3-dimethoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-
yl]ethyl}-1H-1,2,3-triazol-4-yl)acetonitrile (67.0 mg, 0.137 mmol)
was treated by using 5 M aqueous sodium hydroxide solution
(1 ml) to give the title compound 33b (61.1 mg, 0.120 mmol,
88%), in a similar manner described for 28. MS (ESI) m/z 509
(M+H)+. 1H NMR (CDCl3) d 2.45–2.63 (2H, m), 3.40 (3H, s), 3.56–
3.59 (2H, m), 3.83 (3H, s), 4.35–4.38 (1H, m), 4.45–4.61 (2H, m),
5.71 (1H, s), 6.24–6.26 (1H, m), 6.31 (1H, t, J = 3.2 Hz), 6.70 (1H,
d, J = 2.0 Hz), 6.91–6.93 (1H, m), 7.03–7.04 (1H, m), 7.16 (1H, t,
J = 8.1 Hz), 7.26–7.32 (3H, m), 7.49 (1H, s). Anal. Calcd for
C
26H25N4O5ClÁ2.75H2OÁ0.1CHCl3: C, 54.95; H, 5.42; N, 9.82. Found:
C, 54.81; H, 4.95; N, 9.52.
4.1.1.76.
(1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3-tri
azol-5-yl)methanol.
Ethyl 1-{2-[(4R,6S)-8-chloro- 6-(2,3-
dimethoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-
yl]ethyl}-1H-1,2,3-triazole-5-carboxylate (61.6 mg, 0.118 mmol)
was treated by using lithium aluminum hydride (13.4 mg,
0.353 mmol) to give the title compound (53.3 mg, 0.111 mmol,
94%), in a similar manner described for 25. MS (ESI) m/z 481
(M+H)+. 1H NMR (CDCl3) d 2.37 (1H, br s), 2.67–2.73 (2H, m),
3.43 (3H, s), 3.86 (3H, s), 4.43–4.47 (1H, m), 4.63–4.76 (4H, m),
5.75 (1H, s), 6.31–6.33 (1H, m), 6.37 (1H, t, J = 3.2 Hz), 6.74 (1H,
d, J = 2.0 Hz), 6.96 (1H, dd, J = 7.9, 1.3 Hz), 7.09–7.10 (1H, m), 7.20
(1H, t, J = 7.9 Hz), 7.32–7.38 (3H, m), 7.53 (1H, s).
4.1.1.80. 2-[(1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3-
triazol-4-yl)methoxy]acetic acid (33d).
Compound 32d
(69.7 mg, 0.123 mmol) was treated by using potassium carbonate
(51.0 mg, 0.37 mmol) to give the title compound 33d (63.3 mg,
0.117 mmol, 96%), in a similar manner described for 10. MS (ESI)
m/z 539 (M+H)+. 1H NMR (CDCl3) d 2.47–2.60 (2H, m), 3.38 (3H,
s), 3.81 (5H, s), 4.35–4.37 (1H, m), 4.45–4.61 (4H, m), 5.69 (1H,
s), 6.23–6.26 (1H, m), 6.27–6.29 (1H, m), 6.68 (1H, s), 6.89–6.92
(1H, m), 7.01–7.02 (1H, m), 7.12–7.17 (1H, m), 7.25–7.30 (5H,
m), 7.63 (1H, s). Anal. Calcd for C27H27N4O6ClÁ1.75H2OÁ0.4CHCl3:
C, 53.20; H, 5.10; N, 9.06. Found: C, 53.41; H, 5.22; N, 8.39.
4.1.1.77.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3-tria-
zol-5-yl)acetonitrile. (1-{2-[(4R,6S)-8-Chloro-6-(2,3-dime-
2-(1-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxyphenyl)-
4.1.1.81. Methyl 2,2-dimethyl-3-(prop-2-yn-1-yloxy)propano-
thoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-
1H-1,2,3-triazol-5-yl)methanol (53.3 mg, 0.111 mmol) was treated
by using methanesulfonyl chloride (0.013 ml, 0.166 mmol) to give
methanesulfonate (83.0 mg, 0.111 mmol, quant.). The methanesul-
fonate was treated by sodium cyanide (14.6 mg, 0.297 mmol) to
give the title compound (20.2 mg, 0.041 mmol, 37%), in a similar
manner described for 26 and 27. MS (ESI) m/z 491 (M+H)+. 1H
NMR (CDCl3) d 2.66–2.71 (2H, m), 3.44 (3H, s), 3.77 (2H, s), 3.87
(3H, s), 4.42 (1H, t, J = 6.6 Hz), 4.58–4.72 (2H, m), 5.77 (1H, s),
ate.
To an ice-cooling N,N-dimethylformamide solution
(40 ml) of methyl 2,2-dimethyl-3-hydroxypropionate (611 mg,
4.62 mmol), sodium hydride (60% in oil, 220 mg, 5.50 mmol) was
added. The resulting mixture was stirred for 5 min. While still
ice-cooling, propargyl bromide (500 mg, 4.20 mmol) was added
to the reaction mixture. The solution was gradually warmed to
room temperature and stirred overnight. Distilled water was added
to the reaction mixture, and the organic materials were extracted
with diethyl ether. The organic layer was washed with brine and

M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
3087
dried over Na2SO4, and then concentrated in vacuo. The residue
was purified by silica gel column chromatography (ethyl acetate–
n-hexane = 1:10) to give the title compound (554 mg, 3.25 mmol,
70%). 1H NMR (CDCl3) d 1.21 (6H, s), 2.40–2.42 (1H, m), 3.53 (2H,
s), 3.69 (3H, s), 4.16–4.13 (2H, m).
4.59 (2H, m), 4.62–4.72 (2H, m), 5.76 (1H, s), 6.31–6.32 (1H, m),
6.37–6.39 (1H, m), 6.73 (1H, d, J = 2.0 Hz), 6.96–6.98 (1H, m),
7.10–7.11 (1H, m), 7.22 (1H, t, J = 7.9 Hz), 7.31–7.38 (4H, m), 7.64
(1H, s). 5-Isomer (high polarity fraction): MS (ESI) m/z 609
(M+H)+. 1H NMR (CDCl3) d 0.77–0.83 (6H, m), 1.76–1.83 (4H, m),
2.62–2.80 (2H, m), 3.43 (3H, s), 3.63 (3H, s), 3.86 (3H, s), 4.50–
4.56 (2H, m), 4.65–4.81 (2H, m), 5.75 (1H, s), 6.32–6.34 (1H, m),
6.36–6.38 (1H, m), 6.73 (1H, d, J = 2.2 Hz), 6.95 (1H, dd, J = 8.1,
1.5 Hz), 7.09–7.10 (1H, m), 7.17 (1H, t, J = 8.1 Hz), 7.32–7.38 (3H,
m), 7.57 (1H, s).
4.1.1.82. Methyl 2-[(1-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxy-
phenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-
1,2,3-triazol-4-yl)methoxy]-2-methylpropanoate (32e) and
methyl 2-[(1-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxyphenyl)-4H,
6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3-tria-
zol-5-yl)methoxy]-2-methylpropanoate.
Compound
31
4.1.1.86. 2-[(1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3-
(145 mg, 0.341 mmol) was treated by using methyl 2-methyl-2-
(2-propynyloxy)propanoate (160 mg, 1.02 mmol) to give the title
compounds, 4-isomer 32e (69.2 mg, 0.119 mmol, 47%) and 5-iso-
mer (50.1 mg, 34%), in a similar manner described for 32a. 4-Iso-
mer 32e (low polarity fraction): MS (ESI) m/z 581 (M+H)+. 1H
NMR (CDCl3) d 1.47–1.48 (6H, m), 2.56–2.73 (2H, m), 3.43–3.44
(3H, m), 3.73–3.73 (3H, m), 3.86–3.86 (3H, m), 4.40–4.42 (1H,
m), 4.58–4.59 (2H, m), 4.62–4.69 (2H, m), 5.76 (1H, s), 6.30–6.31
(1H, m), 6.37–6.39 (1H, m), 6.72–6.73 (1H, m), 6.97 (1H, d,
J = 8.3 Hz), 7.09–7.11 (1H, m), 7.31–7.38 (1H, m), 7.33–7.36 (3H,
m), 7.63 (1H, s). 5-Isomer (high polarity fraction): MS (ESI) m/z
581 (M+H)+. 1H NMR (CDCl3) d 1.42–1.43 (6H, m), 2.62–2.78 (2H,
m), 3.43–3.43 (3H, m), 3.64–3.65 (3H, m), 3.86–3.86 (3H, m),
4.49–4.52 (1H, m), 4.55–4.57 (2H, m), 4.65–4.80 (2H, m), 5.75
(1H, s), 6.32–6.33 (1H, m), 6.36–6.38 (1H, m), 6.73 (1H, s), 6.95
(1H, d, J = 8.1 Hz), 7.09–7.10 (1H, m), 7.18 (1H, t, J = 8.1 Hz),
7.33–7.38 (3H, m), 7.57 (1H, s).
triazol-4-yl)methoxy]-2-ethylbutanoic acid (33f).
Com-
pound 32f (140 mg, 0.23 mmol) was dissolved in methanol–
water–tetrahydrofuran (2:1:2, 2.5 ml). To the resulting solution,
5 N aqueous sodium hydroxide solution (0.23 ml, 1.15 mmol)
was added and stirred overnight at 80 °C. After the reaction mix-
ture was neutralized with an ion exchange resin (Amberlite IR-
120B), the resin was filtered out and the filtrate was concentrated
in vacuo. The residue was purified by preparative thin layer chro-
matography on silica gel (methanol–chloroform = 1:10) to give the
title compound 33f (92 mg, 0.15 mmol, 67%). MS (ESI) m/z 595
(M+H)+. 1H NMR (CDCl3) d 0.77–0.86 (6H, m), 1.75–1.90 (4H, m),
2.53–2.70 (2H, m), 3.43 (3H, s), 3.86 (3H, s), 4.37–4.41 (1H, m),
4.47–4.51 (2H, m), 4.59–4.68 (2H, m), 5.75 (1H, s), 6.28–6.29
(1H, m), 6.35–6.37 (1H, m), 6.72 (1H, d, J = 2.0 Hz), 6.95–6.97
(1H, m), 7.08–7.10 (1H, m), 7.20 (1H, t, J = 7.9 Hz), 7.27–7.37 (3H,
m), 7.59 (1H, s). Anal. Calcd for C31H35N4O6ClÁ2H2OÁ0.25 1,4-diox-
ane: C, 58.85; H, 6.33; N, 8.58. Found: C, 59.35; H, 6.00; N, 8.10.
4.1.1.83. 2-[(1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3-
4.1.1.87. Ethyl 1-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-pyraz
triazol-4-yl)methoxy]-2-methylpropanoic acid (33e).
Com-
pound 32e (69.2 mg, 0.12 mmol) was treated by using potassium
carbonate (49.4 mg, 0.36 mmol) to give the title compound 33e
(50.5 mg, 0.089 mmol, 75%), in a similar manner described for 10.
MS (ESI) m/z 567 (M+H)+. 1H NMR (CDCl3) d 1.47 (6H, s), 2.52–
2.67 (2H, m), 3.43 (3H, s), 3.86 (3H, s), 4.38–4.40 (1H, m), 4.56–
4.65 (4H, m), 5.74 (1H, s), 6.27–6.29 (1H, m), 6.35–6.37 (1H, m),
6.72–6.73 (1H, m), 6.96 (1H, d, J = 8.3 Hz), 7.08–7.10 (1H, m),
7.20 (1H, t, J = 7.9 Hz), 7.26–7.37 (4H, m), 7.56 (1H, s). Anal. Calcd
for C29H31N4O6ClÁ0.5H2O: C, 60.47; H, 5.60; N, 9.73. Found: C,
60.56; H, 5.94; N, 9.88.
ole-5-carboxylate and
3-dimethoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-
yl]ethy l}-1H-pyrazole-3-carboxylate. To an N,N-dimethyl-
ethyl 1-{2-[(4R,6S)-8-chloro-6-(2,
formamide solution (2.0 ml) of ethyl 1H-pyrazole-3-carboxylate
(111 mg, 0.79 mmol), sodium hydride (60% in oil, 70 mg,
1.75 mmol) was added under ice-cooling. The resulting mixture
was stirred for 5 min. To the reaction mixture, an N,N-dimethyl-
formamide solution (5.0 ml) of compound 26 (815 mg, 1.71 mmol)
and tetrabutylammonium iodide (209 mg, 0.56 mmol) were added.
While warming to room temperature, the resulting mixture was
stirred for 14 h. The reaction mixture was concentrated in vacuo.
To the residue, diethyl ether and distilled water were added. The
organic layer was separated and dried over Na2SO4. The solvent
was distilled off under reduced pressure. The residue was purified
by silica gel column chromatography (methanol–dichlorometh-
ane = 1:100) to give the title compounds, 3-isomer (92 mg,
0.18 mmol, 10%) and 5-isomer (78 mg, 0.15 mmol, 9%), respec-
tively. 3-isomer: MS (ESI) m/z 522 (M+H)+. 1H NMR (CDCl3) d
1.38 (3H, t, J = 7.1 Hz), 2.56–2.69 (2H, m), 3.43 (3H, s), 3.86 (3H,
s), 4.28–4.34 (1H, m), 4.38 (2H, q, J = 7.1 Hz), 4.43–4.63 (2H, m),
5.74 (1H, s), 6.27–6.32 (1H, m), 6.35–6.38 (1H, m), 6.71–6.77
(2H, m), 6.97 (1H, dd, J = 8.1, 1.5 Hz), 7.07–7.10 (1H, m), 7.21
(1H, t, J = 8.0 Hz), 7.29–7.39 (3H, m), 7.44 (1H, d, J = 2.2 Hz). 5-iso-
mer: MS (ESI) m/z 522 (M+H)+. 1H NMR (CDCl3) d 1.33 (3H, t,
J = 7.1 Hz), 2.48–2.67 (2H, m), 3.43 (3H, s), 3.85 (3H, s), 4.30 (2H,
q, J = 7.1 Hz), 4.38–4.46 (1H, m), 4.81–4.90 (2H, m), 5.72 (1H, s),
6.31–6.40 (2H, m), 6.73 (1H, d, J = 2.2 Hz), 6.81 (1H, d, J = 2.0 Hz),
6.95 (1H, dd, J = 8.1, 1.2 Hz), 7.08 (1H, t, J = 2.1 Hz), 7.19 (1H, t,
J = 8.1 Hz), 7.28–7.38 (2H, m), 7.40–7.46 (2H, m).
4.1.1.84.
ate.
Methyl
2-ethyl-2-(2-propynyloxy)butano-
Methyl 2-ethyl-2-hydroxybutanoate (1.10 g, 7.52 mmol)
was treated by sodium hydride (55% in oil, 0.36 g, 8.28 mmol)
and propargyl bromide (0.85 ml, 11.3 mmol) to give the title com-
pound (0.38 g, 2.06 mmol, 27%), in a similar manner described for
methyl 2,2-dimethyl-3-(prop-2-yn-1-yloxy)propanoate. 1H NMR
(CDCl3) d 0.85–0.90 (6H, m), 1.80–1.84 (4H, m), 2.42 (1H, t,
J = 2.4 Hz), 3.74 (3H, s), 4.13 (2H, d, J = 2.4 Hz).
4.1.1.85. Methyl 2-[(1-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxy-
phenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-
1,2,3-triazol-4-yl)methoxy]-2-ethylbutanoate (32f) and methyl
2-[(1-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxyphenyl)-4H,6H-pyr
rolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3-triazol-5-yl)
methoxy]-2-ethylbutanoate.
Compound 31 (140 mg, 0.33 m
mol) was treated by using methyl 2-ethyl-2-(2-propynyloxy)but-
anoate (182 mg, 0.99 mmol) to give the title compounds, 4-isomer
32f (117 mg, 0.19 mmol, 58%) and 5-isomer (23 mg, 0.04 mmol,
12%), in a similar manner described for 32a. 4-Isomer 32f (low
polarity fraction): MS (ESI) m/z 609 (M+H)+. 1H NMR (CDCl3) d
0.83–0.87 (6H, m), 1.85 (4H, q, J = 7.5 Hz), 2.58–2.74 (2H, m),
3.44 (3H, s), 3.73 (3H, s), 3.86 (3H, s), 4.40–4.44 (1H, m), 4.52–
4.1.1.88.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1 H-pyra
zol -3-yl)methanol. 1-{2-[(4R,6S)-8-Chloro-6-(2,3-dime-
(1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-

3088
M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
thoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]
ethyl}-1H-pyrazole-3-carboxylate (91 mg, 0.17 mmol) was trea-
ted by using lithium aluminum hydride (11 mg, 0.29 mmol) to
give the title compound (93 mg, 0.17 mmol, quant.), in a similar
manner described for 25. MS (ESI) m/z 480 (M+H)+. 1H NMR
(CDCl3) d 2.53–2.64 (2H, m), 3.44 (3H, s), 3.86 (3H, s), 4.27–
4.53 (3H, m), 4.64 (2H, s), 5.74 (1H, s), 6.17 (1H, d, J = 2.2 Hz),
6.28–6.32 (1H, m), 6.35–6.39 (1H, m), 6.70–6.77 (1H, m), 6.97
(1H, dd, J = 8.3, 1.5 Hz), 7.08–7.11 (1H, m), 7.21 (1H, t,
J = 8.1 Hz), 7.29–7.40 (4H, m). IR (ATR) cmÀ1 2937, 1720, 1587,
1277, 1223, 1101, 1032, 750, 715.
4.1.1.92. 2-(1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-4
H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-pyrazol-5
-yl)acetonitrile.
1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyph
enyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-pyra
zol-5-yl)methanol (76 mg, 0.16 mmol) was treated using methane-
sulfonyl chloride (0.016 ml, 0.15 mmol) and triethylamine
(0.024 ml, 0.17 mmol) to give the title compound (97 mg,
0.17 mmol, quant.). This methanesulfonate (88 mg, 0.16 mmol)
was treated by using sodium cyanide (16 mg, 0.32 mmol) to give
the title compound (34 mg, 0.07 mmol, 43%), in a similar manner
described for 26 and 27. MS (ESI) m/z 489 (M+H)+. 1H NMR (CDCl3)
d 2.51–2.67 (2H, m), 3.43 (3H, s), 3.72 (2H, s), 3.87 (3H, s), 4.27–
4.49 (3H, m), 5.74 (1H, s), 6.21–6.26 (1H, m), 6.29–6.32 (1H, m),
6.36–6.39 (1H, m), 6.75 (1H, d, J = 2.2 Hz), 6.94–7.00 (1H, m),
7.09–7.15 (1H, m), 7.22 (1H, t, J = 8.0 Hz), 7.29–7.41 (3H, m),
7.43–7.46 (1H, m).
4.1.1.89.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-pyrazol-
3-yl)acetonitrile. (1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyp
2-(1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
henyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-pyr
azol-3-yl)methanol (4.69 g, 9.78 mmol) was dissolved in dichloro-
methane solution (47 ml). To the solution, triphenylphosphine
(3.08 g, 11.73 mmol) and carbon tetrabromide (3.89 g, 11.73
mmol) were added under ice-cooling. The resulting mixture was
stirred for 1 h while kept under ice-cooling. At the same tempera-
ture, sodium cyanide (2.40 g, 48.88 mmol) and dimethylsulfoxide
(47 ml) were added. The reaction mixture was stirred at 40 °C for
2 h (disappearance of a bromine derivative and generation of the
intended product were confirmed by TLC). The reaction mixture
was cooled to room temperature, and then brine and ethyl acetate
were added. The organic layer was separated and washed with
water and brine, and then dried over Na2SO4. The solvent was dis-
tilled off under reduced pressure and the residue was subjected to
column chromatography (methanol–chloroform = 1:200) to give
the title compound (3.44 g, 7.04 mmol, 72%). MS (ESI) m/z 489
(M+H)+. 1H NMR (CDCl3) d 2.52–2.62 (2H, m), 3.44 (3H, s), 3.70
(2H, s), 3.86 (3H, s), 4.27–4.48 (3H, m), 5.74 (1H, s), 6.21 (1H, dd,
J = 2.2, 0.5 Hz), 6.29–6.32 (1H, m), 6.37 (1H, t, J = 3.2 Hz), 6.73
(1H, d, J = 2.0 Hz), 6.97 (1H, dd, J = 8.1, 1.5 Hz), 7.09 (1H, dd,
J = 2.9, 1.5 Hz), 7.21 (1H, t, J = 8.0 Hz), 7.30–7.39 (4H, m).
4.1.1.93.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-pyrazol-
5-yl)acetic acid (35b). 2-(1-{2-[(4R,6S)-8-Chloro-6-(2,3-dime
2-(1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
thoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]et hyl}
-1H-pyrazol-5-yl)acetonitrile (88 mg, 0.18 mmol) was treated by
using 5 M aqueous sodium hydroxide solution to give the title
compound 35b (25 mg, 0.05 mmol, 27%), in a similar manner de-
scribed for 28. MS (ESI) m/z 508 (M+H)+. 1H NMR (CDCl3) d 2.47–
2.78 (2H, m), 3.40 (3H, d, J = 1.2 Hz), 3.47–3.73 (2H, m), 3.83 (3H,
d, J = 1.7 Hz), 4.14–4.47 (3H, m), 5.72 (1H, s), 6.10 (1H, s), 6.27–
6.37 (2H, m), 6.69–6.76 (1H, m), 6.87–6.97 (1H, m), 7.04–7.09
(1H, m), 7.10–7.19 (1H, m), 7.29–7.43 (4H, m). IR (ATR) cmÀ1
2935, 1718, 1587, 1481, 1277, 1173, 1099, 1039, 1003, 760, 714.
Anal. Calcd for C27H26ClN3O5Á1.25H2OÁ0.5CHCl3: C, 55.97; H, 4.95;
N, 7.12. Found: C, 55.93; H, 4.79; N, 6.93.
4.1.1.94. Ethyl 1-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-pyrazole
-4-carboxylate (34c).
Compound 26 (719 mg, 1.50 mmol)
was treated by using ethyl 1H-pyrazole-4-carboxylate (261 mg,
1.86 mmol) and sodium hydride (55% in oil, 92 mg, 2.11 mmol)
to give the title compound 34c (661 mg, 1.27 mmol, 84%). 1H
NMR (CDCl3) d 1.32 (3H, t, J = 7.1 Hz), 2.57–2.69 (2H, m), 3.44
(3H, s), 3.86 (3H, s), 4.27 (2H, q, J = 7.1 Hz), 4.32–4.55 (3H, m),
5.74 (1H, s), 6.30–6.33 (1H, m), 6.36–6.39 (1H, m), 6.71–6.75
(1H, m), 6.95–6.99 (1H, m), 7.08–7.11 (1H, m), 7.24–7.18 (1H,
m), 7.38–7.29 (3H, m), 7.92–7.87 (2H, m).
4.1.1.90.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-pyrazol-
3-yl)acetic acid (35a). 2-(1-{2-[(4R,6S)-8-Chloro-6-(2,3-di m
2-(1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
ethoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}
-1H-pyrazol-3-yl)acetonitrile (3.44 g, 7.04 mmol) was treated by
using 5 M aqueous sodium hydroxide solution (28 ml) to give the
title compound 35a (3.08 g, 6.06 mmol, 86%), in a similar manner
described for 28. 1H NMR (CDCl3) d 2.50–2.66 (2H, m), 3.44 (3H,
s), 3.73 (2H, s), 3.86 (3H, s), 4.29–4.35 (1H, m), 4.35–4.50 (2H,
m), 5.74 (1H, s), 6.10 (1H, d, J = 2.2 Hz), 6.29–6.32 (1H, m), 6.37
(1H, t, J = 3.2 Hz), 6.73 (1H, d, J = 2.2 Hz), 6.97 (1H, dd, J = 8.1,
1.5 Hz), 7.09 (1H, dd, J = 2.9, 1.7 Hz), 7.21 (1H, t, J = 8.1 Hz), 7.29–
7.41 (4H, m). IR (ATR) cmÀ1 2933, 1716, 1481, 1277, 1173, 1099,
1051, 1003, 758, 714. Anal. Calcd for C27H26ClN3O5: C, 63.84; H,
5.16; N, 8.27. Found: C, 63.66; H, 5.18; N, 8.02.
4.1.1.95.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-pyra-
zole-4-carboxylic acid (35c). Compound 34c (470 mg,
1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
0.90 mmol) was treated by using 5 N aqueous sodium hydroxide
solution (9.0 ml) to give the title compound 35c (280 mg,
0.57 mmol, 63%), in a similar manner described for 10. MS (ESI) m/
z 494 (M+H)+. 1H NMR (CDCl3) d 2.59–2.67 (2H, m), 3.44 (3H, s),
3.86 (3H, s), 4.32–4.55 (3H, m), 5.74 (1H, s), 6.30–6.33 (1H, m),
6.36–6.39 (1H, m), 6.73–6.74 (1H, m), 6.95–6.99 (1H, m), 7.08–
7.11 (1H, m), 7.18–7.24 (1H, m), 7.26–7.26 (2H, m), 7.28–7.38 (3H,
m), 7.97–7.92 (2H, m). Anal. Calcd for C26H24ClN3O5Á0.25H2OÁ0.25
n-hexane: C, 63.52; H, 5.43; N, 8.08. Found: C, 63.46; H, 5.28; N, 8.01.
4.1.1.91. (1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-4H,
6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-pyrazol-5-y
l)methanol.
Ethyl 1-{2-[(4R,6S)-8-chloro-6-(2,3-dimet hoxyp
henyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-pyr
azole-5-carboxylate (78 mg, 0.15 mmol) was treated by using lith-
ium aluminum hydride (9.3 mg, 0.25 mmol) to give the title com-
pound (72 mg, 0.15 mmol, quant.), in a similar manner described
for 25. MS (ESI) m/z 480 (M+H)+. 1H NMR (CDCl3) d 2.56–2.71
(2H, m), 3.43 (3H, s), 3.67–3.72 (1H, m), 3.86 (3H, s), 4.37–4.55
(3H, m), 4.60–4.70 (2H, m), 5.74 (1H, s), 6.16 (1H, d, J = 1.7 Hz),
6.31–6.40 (2H, m), 6.74 (1H, d, J = 2.2 Hz), 6.96 (1H, dd, J = 8.3,
1.5 Hz), 7.07–7.10 (1H, m), 7.18–7.23 (1H, m), 7.30–7.44 (3H, m).
IR (ATR) cmÀ1 2935, 1587, 1481, 1277, 1099, 1055, 1005, 748.
4.1.1.96.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-pyrazol-
4-yl)methanol. Compound 34c (592 mg, 1.20 mmol) was
(1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
treated by using lithium aluminum hydride (187 mg, 4.93 mmol)
to give the title compound (512 mg, 1.07 mmol, 89%), in a similar
manner described for 25. 1H NMR (CDCl3) d 2.56–2.63 (2H, m),
3.44 (3H, s), 3.86 (3H, s), 4.29–4.57 (5H, m), 5.73 (1H, s), 6.29–
6.32 (1H, m), 6.35–6.39 (1H, m), 6.71–6.79 (1H, m), 6.93–7.00

M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
3089
(1H, m), 7.06–7.12 (1H, m), 7.18–7.24 (1H, m), 7.30–7.40 (3H, m),
7.48–7.41 (2H, m).
4.1.1.101. Ethyl 2-(2-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxyphe
nyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-2H-1, 2,
3, 4-tetrazol-5-yl)acetate (34f) and Ethyl 2-(2-{2-[(4R,6S)-8-
chloro-6-(2,3-dimethoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]
benzoxazepin-4-yl]ethyl}-1H-1,2,3,4-tetrazol-5-yl)acetate
4.1.1.97.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-pyrazol-
4-yl)acetonitrile. (1-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxy-
2-(1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
(34g).
Compound 26 (156 mg, 0.326 mmol) was treated with
phenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-
pyrazol-4-yl)methanol (244 mg, 0.51 mmol) was treated by using
triphenylphosphine (320 mg, 1.22 mmol), carbon tetrabromide
(370 mg, 1.12 mmol) and sodium cyanide (124 mg, 2.53 mmol) to
give the title compound (139 mg, 0.28 mmol, 56%). MS (ESI) m/z
489 (M+H)+. 1H NMR (CDCl3) d 2.55–2.64 (2H, m), 3.44 (3H, s),
3.53 (2H, s), 3.86 (3H, s), 4.29–4.52 (3H, m), 5.73–5.81 (1H, m),
6.28–6.40 (2H, m), 6.72–6.76 (1H, m), 6.94–7.00 (1H, m), 7.07–
7.15 (1H, m), 7.19–7.24 (1H, m), 7.29–7.45 (5H, m).
ethyl 1H-tetrazole 5-acetate (82.3 mg, 0.527 mmol), potassium car-
bonate (109 mg, 0.791 mmol) and tetrabutylammonium iodide
(97.4 mg, 0.264 mmol) to give the title compounds, 2H-isomer 34f
(85.4 mg, 0.159 mmol, 49%) and 1H-isomer 34g (65.4 mg,
0.122 mmol, 37%). 2H-Isomer 34f (low polarity fraction): MS (ESI)
m/z 538 (M+H)+. 1H NMR (CDCl3) d 1.24 (3H, t, J = 7.2 Hz), 2.75–
2.79 (2H, m), 3.44 (3H, s), 3.86 (3H, s), 3.93 (2H, s), 4.18 (2H, q,
J = 7.2 Hz), 4.41–4.45 (1H, m), 4.91–4.95 (2H, m), 5.75 (1H, s),
6.32–6.34 (1H, m), 6.38–6.39 (1H, m), 6.72 (1H, d, J = 2.0 Hz), 6.96
(1H, dd, J = 8.1, 1.3 Hz), 7.10–7.11 (1H, m), 7.21 (1H, t, J = 8.1 Hz),
7.32–7.38 (3H, m). 1H-Isomer 34g (high polarity fraction): MS
(ESI) m/z 538 (M+H)+. 1H NMR (CDCl3) d 1.24 (3H, t, J = 7.2 Hz),
2.66–2.76 (2H, m), 3.43 (3H, s), 3.86 (3H, s), 3.99–4.00 (2H, m),
4.14–4.20 (2H, m), 4.40–4.43 (1H, m), 4.60–4.67 (2H, m), 5.75 (1H,
s), 6.30–6.32 (1H, m), 6.38–6.39 (1H, m), 6.74 (1H, d, J = 2.2 Hz),
6.97 (1H, dd, J = 8.1, 1.7 Hz), 7.10–7.12 (1H, m), 7.19 (1H, t,
J = 8.1 Hz), 7.33–7.40 (3H, m).
4.1.1.98.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-pyrazol-
4-yl)acetic acid (35d). 2-(1-{2-[(4R,6S)-8-chloro-6-(2,3-
2-(1-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
dimethoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]et
hyl}-1H-pyrazol-4-yl)acetonitrile (139 mg, 0.28 mmol) was treated
by using 5 M aqueous sodium hydroxide solution (2.42 ml) to give
the title compound 35d (80 mg, 0.16 mmol, 56%), in a similar man-
ner described for 28. MS (ESI) m/z 508 (M+H)+. 1H NMR (CDCl3) d
2.52–2.61 (2H, m), 3.42 (3H, s), 3.44 (2H, s), 3.85 (3H, s), 4.27–
4.48 (3H, m), 5.72 (1H, s), 6.25–6.32 (1H, m), 6.34–6.37 (1H, m),
6.71–6.78 (1H, m), 6.92–7.00 (1H, m), 7.06–7.13 (1H, m), 7.16–
7.22 (1H, m), 7.42–7.27 (5H, m).
4.1.1.102. 2-(2-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl)ethyl]-2H-1,2,3,4-t
etrazol-5-yl}acetic acid (35f).
Compound 34f (85.4 mg,
0.159 mmol) was treated by using potassium carbonate (65.8 mg,
0.425 mmol) to give the title compound 35f (61.2 mg, 0.120 mmol,
76%), in a similar manner described for 10. MS (ESI) m/z 510
(M+H)+. 1H NMR (CDCl3) d 2.56–2.67 (2H, m), 3.38 (3H, s), 3.61–
3.66 (2H, m), 3.81 (3H, s), 4.35–4.40 (1H, m), 4.66–4.83 (2H, m),
5.68 (1H, s), 6.23–6.28 (2H, m), 6.66–6.68 (1H, m), 6.87–6.89
(1H, m), 7.10–7.15 (1H, m), 7.11–7.13 (1H, m), 7.23–7.30 (3H,
m). Anal. Calcd for C25H24N5O5ClÁ2.65H2O: C, 53.84; H, 5.30; N,
12.56. Found: C, 53.39; H, 4.50; N, 12.28.
Anal. Calcd for C27H26ClN3O5Á1.0 H2O: C, 61.65; H, 5.37; N, 7.99.
Found: C, 61.33; H, 5.23; N, 7.64.
4.1.1.99. Ethyl 2-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-2H-1,2,3,4-t
etrazol-5-carboxylate (34e) and ethyl 2-{2-[(4R,6S)-8-chloro-6-
(2,3-dimethoxyphenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin
-4-yl]ethyl}-1H-1,2,3,4-tetrazol-5-carboxylate.
Compound
26 (134 mg, 0.280 mmol) was treated using ethyl 1H-tetrazole 5-
carboxylate (105 mg, 0.561 mmol), sodium hydride (60% in oil,
70 mg, 1.75 mmol), and tetrabutylammonium iodide (209 mg,
0.56 mmol) to give the title compounds, 2H-isomer 34e (63.3 mg,
0.121 mmol, 43%) and 1H-isomer (30.3 mg, 0.058 mmol, 21%),
which were obtained respectively. 2H-Isomer 34e (low polarity
fraction): MS (ESI) m/z 525 (M+H)+. 1H NMR (CDCl3) d 1.45 (3H, t,
J = 7.2 Hz), 2.79–2.85 (2H, m), 3.44 (3H, s), 3.86 (3H, s), 4.39–4.43
(1H, m), 4.51 (2H, q, J = 7.2 Hz), 5.01–5.06 (2H, m), 5.75 (1H, s),
6.32–6.33 (1H, m), 6.38–6.39 (1H, m), 6.72 (1H, d, J = 2.2 Hz),
6.96–6.98 (1H, m), 7.09–7.12 (1H, m), 7.21 (1H, t, J = 7.9 Hz),
7.30–7.36 (3H, m). 1H-Isomer (high polarity fraction): MS (ESI)
m/z 525 (M+H)+. 1H NMR (CDCl3) d 1.42–1.47 (3H, m), 2.60–2.78
(2H, m), 3.43 (3H, s), 3.86 (3H, s), 4.44–4.53 (3H, m), 5.06–5.09
(2H, m), 5.74–5.75 (1H, m), 6.32–6.35 (1H, m), 6.38–6.39 (1H,
m), 6.72–6.75 (1H, m), 6.96–6.98 (1H, m), 7.09–7.12 (1H, m),
7.21 (1H, t, J = 8.1 Hz), 7.33–7.39 (3H, m).
4.1.1.103. 2-(2-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3,4-t
etrazol-5-yl)acetic acid (35g).
Compound 34g (65.4 mg,
0.122 mmol) was treated by using potassium carbonate (50.4 mg,
0.365 mmol) to give the title compound 35g (47.3 mg, 0.093 mmol,
76%), in a similar manner described for 10. MS (ESI) m/z 510
(M+H)+. 1H NMR (CDCl3) d 2.45–2.55 (2H, m), 3.34 (3H, s), 3.53–
3.55 (2H, m), 3.76 (3H, s), 4.32–4.45 (3H, m), 5.66 (1H, s), 6.19–
6.25 (2H, m), 6.64–6.66 (1H, m), 6.81–6.83 (1H, m), 6.92–6.94
(1H, m), 7.08–7.13 (1H, m), 7.16–7.22 (2H, m), 7.30–7.32 (1H,
m). Anal. Calcd for C25H24N5O5ClÁ4.7H2O: C, 50.50; H, 5.66; N,
11.78. Found: C, 50.17; H, 4.58; N, 11.30.
4.1.1.104. 2-[2-(4-Methoxybenzyl)-2H-1,2,3,4-tetrazol-5-yl]-1-
ethanol.
Ethyl 2-[2-(4-methoxybenzyl)-2H-1,2,3,4-tetrazol-
5-yl]acetate23 (5.24 g, 18.9 mmol) was treated using lithium alu-
minum hydride (1.17 g, 30.8 mmol) to give the title compound
(4.44 g, 18.9 mmol, quant.), in a similar manner described for 25.
MS (ESI) m/z 235 (M+H)+. 1H NMR (CDCl3) d 2.34–2.41 (1H, m),
3.12 (2H, t, J = 5.9 Hz), 3.80 (3H, s), 3.99–4.05 (2H, m), 5.63–5.69
(2H, m), 6.87–6.92 (2H, m), 7.27–7.36 (2H, m). IR (ATR) cmÀ1
2937, 1612, 1514, 1248, 1176, 1026, 779.
4.1.1.100.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-2H-1,2,3,4-t
etrazol-5-carboxylic acid (35e). Compound 34e (60.3 mg,
2-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
0.115 mmol) was treated by using potassium carbonate (47.7 mg,
0.345 mmol) to give the title compound 35e (42.6 mg, 0.086 mmol,
75%), in a similar manner described for 10. MS (ESI) m/z 496 (M+H)+.
1H NMR (CDCl3) d 2.41–2.55 (2H, m), 3.35 (3H, s), 3.79 (3H, s), 4.32–
4.35 (1H, m), 4.49–4.51 (1H, m), 4.66–4.68 (1H, m), 5.63–5.66 (1H,
m), 6.15–6.22 (2H, m), 6.64–6.67 (1H, m), 6.83–6.94 (2H, m), 7.07–
4.1.1.105. 2-[2-(4-Methoxybenzyl)-2H-1,2,3,4-tetrazol-5-yl]ethyl
methanesulfonate.
2-[2-(4-Methoxybenzyl)-2H-1,2,3,4-tetra
zol-5-yl]-1-ethanol (5.23 g, 22.3 mmol) was treated using meth-
anesulfonyl chloride (2.07 ml, 26.7 mmol) and triethylamine
(4.67 ml, 33.5 mmol) to give the title compound (6.20 g,
19.8 mmol, 89%), in a similar manner described for 26. MS (ESI)
7.10 (1H, m), 7.21–7.25 (3H, m). Anal. Calcd for
C24H22
N5O5ClÁ1H2OÁ0.4CHCl3: C, 52.14; H, 4.45; N, 12.46. Found: C,
51.71; H, 4.04; N, 12.36.

3090
M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
m/z 313 (M+H)+. 1H NMR (CDCl3) d 2.91 (3H, s), 3.30–3.36 (2H, m),
3.80 (3H, s), 4.59–4.64 (2H, m), 5.66 (2H, s), 6.86–6.92 (2H, m),
7.28–7.36 (2H, m). IR (ATR) cmÀ1 1612, 1514, 1350, 1248, 1169,
1028, 960, 906, 779, 526.
715. 1H-Isomer (high polarity fraction): MS (ESI) m/z 538
(M+H)+. 1H NMR (CDCl3) d 2.55–2.77 (2H, m), 2.83–2.98 (2H, m),
2.99–3.14 (2H, m), 3.43 (3H, s), 3.66 (3H, s), 3.86 (3H, s), 4.36–
4.42 (1H, m), 4.58–4.72 (2H, m), 5.75 (1H, s), 6.27–6.33 (1H, m),
6.37–6.41 (1H, m), 6.73 (1H, d, J = 2.2 Hz), 6.95–7.01 (1H, m),
7.10–7.13 (1H, m), 7.21 (1H, t, J = 8.1 Hz), 7.28–7.40 (3H, m). IR
(ATR) cmÀ1 2951, 1736, 1481, 1429, 1275, 1171, 1028, 1003, 760,
715.
4.1.1.106. 3-[2-(4-Methoxybenzyl)-2H-1,2,3,4-tetrazol-5-yl]prop
ionitrile.
2-[2-(4-Methoxybenzyl)-2H-1,2,3,4-tetrazol-5-yl]et
hyl methanesulfonate (6.19 g, 19.8 mmol) was treated using so-
dium cyanide (1.89 g, 38.6 mmol) to give the title compound
(2.77 g, 11.4 mmol, 57%), in a similar manner described for 27.
MS (ESI) m/z 266 (M+Na)+. 1H NMR (CDCl3) d 2.82–2.89 (2H, m),
3.22–3.28 (2H, m), 3.80 (3H, s), 5.66 (2H, s), 6.87–6.93 (2H, m),
7.31–7.37 (2H, m).
4.1.1.111. 3-(2-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-2H-1,2,3,4-
tetrazol-5-yl)propanoic acid (35h).
Compound 34h (123 mg,
0.23 mmol) was treated using potassium carbonate (95 mg,
0.69 mmol) to give the title compound 35h (75 mg, 0.14 mmol,
63%), in a similar manner described for 10.
4.1.1.107. 3-[2-(4-Methoxybenzyl)-2H-1,2,3,4-tetrazol-5-yl]pro-
pionic acid.
3-[2-(4-Methoxybenzyl)-2H-1,2,3,4-tetrazol-5-
1H NMR (CDCl3) d 2.64–2.90 (4H, m), 3.12–3.21 (2H, m), 3.44
(3H, s), 3.86 (3H, s), 4.36–4.46 (1H, m), 4.83–4.95 (2H, m), 5.75
(1H, s), 6.26–6.35 (1H, m), 6.36–6.40 (1H, m), 6.71–6.78 (1H, m),
6.91–7.04 (1H, m), 7.08–7.15 (1H, m), 7.18–7.24 (1H, m), 7.29–
7.40 (3H, m). IR (ATR) cmÀ1 3417, 2935, 1712, 1491, 1279, 1173,
1101, 1063, 823, 762, 717. Anal. Calcd for C26H26ClN5O5Á0.75H2O:
C,58.10; H,5.16; N,13.03. Found: C,58.30; H,4.95; N,12.82.
yl]propionitrile (2.10 g, 8.6 mmol) was treated, to give the title
compound (2.26 g, 8.6 mmol, 99%), in a similar manner described
for 28. MS (ESI) m/z 263 (M+H)+. 1H NMR (CDCl3) d 2.86–2.92
(2H, m), 3.16–3.24 (2H, m), 3.79 (3H, s), 5.64 (2H, s), 6.86–6.91
(2H, m), 7.29–7.35 (2H, m). IR (ATR) cmÀ1 2931, 1712, 1610,
1512, 1440, 1294, 1244, 1213, 1030, 931, 796.
4.1.1.108. Methyl 3-[2-(4-methoxybenzyl)-2H-1,2,3,4-tetrazol-
4.1.1.112. Ethyl
2-(2-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxy-
5-yl]propanoate.
To a methanol solution (17 ml) of 3-[2-(4-
phenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-2H-
1,2,3,4-tetrazol-5-yl)-2-methylpropanoate (34i) and ethyl 2-(2-
{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxyphenyl)-4H,6H-pyrrol-
o[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3,4-tetrazol-5-
methoxybenzyl)-2H-1,2,3,4-tetrazol-5-yl]propionic acid (447 mg,
1.70 mmol) was added tetramethylsilyldiazomethane (2 M hexane
solution, 1.28 ml, 2.56 mmol) under ice-cooling, followed by stir-
ring for 3 h. The solvent was distilled off under reduced pressure
to give the title compound (372 mg, 1.35 mmol, 79%). MS (ESI)
m/z 277 (M+H)+.
yl)-2-methylpropanoate.
In a similar manner described for
34f, compound 26 (179 mg, 0.37 mmol) was treated with ethyl
2,2-dimethyl-2-(1H-tetrazol-5-yl)acetate (138 mg, 0.75 mmol) to
give the title compounds, 2H-isomer 34i (191 mg, 0.34 mmol,
90%) and 1H-isomer (28.7 mg, 0.05 mmol, 13%). 2H-Isomer 34i
(low polarity fraction): MS (ESI) m/z 566 (M+H)+. 1H NMR (CDCl3)
d 1.14 (3H, t, J = 7.1 Hz), 1.64 (6H, s), 2.68–2.80 (2H, m), 3.44 (3H,
s), 3.86 (3H, s), 4.10 (2H, q, J = 7.1 Hz), 4.36–4.39 (1H, m), 4.89–
4.93 (2H, m), 5.76 (1H, s), 6.32–6.33 (1H, m), 6.39 (1H, t,
J = 3.2 Hz), 6.71–6.72 (1H, m), 6.97 (1H, d, J = 8.1 Hz), 7.10–7.11
(1H, m), 7.22 (1H, t, J = 8.1 Hz), 7.31–7.41 (3H,m). 1H-Isomer (high
polarity fraction): MS (ESI) m/z 566 (M+H)+. 1H NMR (CDCl3) d
1.15–1.19 (3H, m), 1.73 (6H, s), 2.65–2.80 (2H, m), 3.43 (3H, s),
3.87 (3H, s), 4.12–4.16 (2H, m), 4.33–4.39 (1H, m), 4.47–4.52
(2H, m), 5.74 (1H, s), 6.32–6.33 (1H, m), 6.38–6.40 (1H, m), 6.73–
6.74 (1H, m), 6.97 (1H, d, J = 8.1 Hz), 7.11–7.12 (1H, m), 7.22 (1H,
t, J = 8.1 Hz), 7.27–7.29 (1H, m), 7.34–7.41 (2H, m).
1H NMR (CDCl3) d 2.81–2.86 (2H, m), 3.17–3.22 (2H, m), 3.68
(3H, s), 3.80 (3H, s), 5.63 (2H, s), 6.82–6.95 (2H, m), 7.29–7.38
(2H, m). IR (ATR) cmÀ1 2952, 1736, 1612, 1514, 1248, 1176,
1028, 841, 779.
4.1.1.109.
ate. To
methoxybenzyl)-2H-1,2,3,4-tetrazol-5-yl]propanoate
Methyl
methanol solution (10 ml) of methyl 3-[2-(4-
(379 mg,
3-[2H-1,2,3,4-tetrazol-5-yl]propano-
a
1.37 mmol) were added 20% palladium hydroxide-carbon
(150 mg) and a 4 N hydrochloric acid in 1,4-dioxane solution
(5 ml). The resulting mixture was stirred in a hydrogen atmosphere
for 6 h. The catalyst was removed by filtration through celite, and
the filtrate was concentrated in vacuo. The residue was subjected
to LH-20 column chromatography (methanol) to give the title com-
pound (178 mg, 1.14 mmol, 83%). MS (ESI) m/z 157 (M+H)+. 1H
NMR (CDCl3) d 2.82–2.91 (2H, m), 3.27–3.36 (2H, m), 3.75 (3H, s).
4.1.1.113.
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl)ethyl]-2H-1,2,3,4-
tetrazol-5-yl}-2-methylpropanoic acid (35i). Compound 34i
2-(2-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl-
4.1.1.110. Methyl 3-(2-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxy-
phenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-2H-
1,2,3,4-tetrazol-5-yl)propanoate (34 h) and Methyl 3-(1-{2-
[(4R,6S)-8-chloro-6-(2,3-dimethoxyphenyl)-4H,6H-pyrrolo[1,2-
a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3,4-tetrazol-5-yl)pro-
(191 mg, 0.34 mmol) was treated using potassium carbonate
(140 mg, 1.02 mmol) to give the title compound 35i (154 mg,
0.29 mmol, 85%), in a similar manner described for 10. MS (ESI)
m/z 538 (M+H)+. 1H NMR (CDCl3) d 1.57–1.58 (6H, m), 2.61–2.78
(2H, m), 3.43 (3H, s), 3.85 (3H, s), 4.36–4.38 (1H, m), 4.81–4.93
(2H, m), 5.74 (1H, s), 6.29–6.32 (1H, m), 6.34–6.36 (1H, m), 6.71
(1H, d, J = 2.2 Hz), 6.94–6.96 (1H, m), 7.07–7.09 (1H, m), 7.19
(1H, t, J = 7.9 Hz), 7.29–7.39 (3H, m). Anal. Calcd for
panoate.
In a similar manner described for 34f, compound 26
(224 mg, 0.52 mmol) was treated using methyl 3-[2H-1,2,3,4-tet-
razol-5-yl]propanoate (88 mg, 0.51 mmol), potassium carbonate
(130 mg, 0.94 mmol) and tetrabutylammonium iodide (173 mg,
0.47 mmol) to give the title compounds, 2H-isomer 34h (143 mg,
0.27 mmol, 51%) and 1H-isomer (57 mg, 0.11 mmol, 20%), respec-
tively. 2H-Isomer 34h (low polarity fraction): MS (ESI) m/z 560
(M+Na)+. 1H NMR (CDCl3) d 2.65–2.86 (2H, m), 3.14–3.22 (2H,
m), 3.44 (3H, s), 3.48–3.51 (2H, m), 3.68 (3H, s), 3.86 (3H, s),
4.35–4.43 (1H, m), 4.81–4.94 (2H, m), 5.75 (1H, s), 6.28–6.34
(1H, m), 6.35–6.40 (1H, m), 6.70–6.73 (1H, m), 6.84–7.01 (1H,
m), 7.07–7.12 (1H, m), 7.17–7.24 (1H, m), 7.28–7.40 (3H, m). IR
(ATR) cmÀ1 2937, 1736, 1489, 1431, 1277, 1171, 1059, 1028, 760,
C
27H28N5O5ClÁ2.5H2OÁ0.3 1,4-dioxane: C, 55.57; H, 5.85; N, 11.49.
Found: C, 55.66; H, 5.31; N, 10.99.
4.1.1.114. Ethyl
1-(2-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxy-
phenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-2H-
1,2,3,4-tetrazol-5-yl)cyclopropanecarboxylate (34j) and ethyl 1-
(2-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxyphenyl)-4H,6H-pyrrol-
o[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3,4-tetrazol-5-
yl)cyclopropanecarboxylate.
In a similar manner described

M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
3091
for 34f, compound 26 (179 mg, 0.37 mmol) was treated with ethyl
1-(2H-1,2,3,4-tetrazol-5-yl)cyclopropanecarboxylate (136 mg,
oxy)acetic acid (1.44 g, 8.17 mmol) was dissolved in dichlorometh-
ane (30 ml). To the resulting solution were added 3-
aminopropionitrile (0.90 ml12.3 mmol), 1-ethyl-3-(3-dimethyl-
aminopropyl)carbodiimide hydrochloride (1.88 g, 9.81 mmol),
and 1-hydroxybenzotriazole (0.38 g, 2.45 mmol). The resulting
mixture was stirred at room temperature for 3 days. The reaction
mixture was diluted with chloroform and washed with brine.
The organic layer was dried over Na2SO4, and then concentrated
to give the title compound (998 mg, 4.37 mmol, 54%). 1H NMR
(CDCl3) d 1.48 (6H, s), 2.67 (2H, t, J = 6.5 Hz), 3.59 (2H, q,
J = 6.5 Hz), 3.76 (3H, s), 3.96 (2H, s).
0.75 mmol) to give the title compounds, 2H-isomer 34j (81 mg,
0.14 mmol, 38%) and 1H-isomer (65 mg, 0.12 mmol, 31%). 2H-Iso-
mer 34j (low polarity fraction): MS (ESI) m/z 564 (M+H)+. 1H NMR
(CDCl3) d 1.15 (3H, t, J = 7.1 Hz), 1.39–1.43 (2H, m), 1.70–1.73 (2H,
m), 2.68–2.83 (2H, m), 3.44 (3H, s), 3.86 (3H, s), 4.12 (2H, q,
J = 7.1 Hz), 4.37–4.40 (1H, m), 4.89–4.93 (2H, m), 5.75 (1H, s),
6.32–6.33 (1H, m), 6.37–6.39 (1H, m), 6.72 (1H, d, J = 2.2 Hz),
6.97 (1H, dd, J = 8.1, 1.5 Hz), 7.10–7.11 (1H, m), 7.21 (1H, t,
J = 8.1 Hz), 7.31–7.38 (3H, m). 1H-Isomer (high polarity fraction):
MS (ESI) m/z 564 (M+H)+. 1H NMR (CDCl3)
d 1.15 (3H, t,
J = 7.1 Hz), 1.40–1.45 (1H, m), 1.51–1.56 (1H, m), 1.79–1.84 (2H,
m), 2.72–2.79 (2H, m), 3.43 (3H, s), 3.86 (3H, s), 4.11 (2H, q,
J = 7.1 Hz), 4.46–4.50 (1H, m), 4.52–4.57 (1H, m), 4.63–4.71 (1H,
m), 5.75 (1H, s), 6.31–6.33 (1H, m), 6.38–6.40 (1H, m), 6.74–6.74
(1H, m), 6.96–6.98 (1H, m), 7.11–7.13 (1H, m), 7.16–7.23 (2H,
m), 7.34–7.41 (2H, m).
4.1.1.120. Methyl 2-{[1-(2-cyanoethyl)-1H-1,2,3,4-tetrazol-5-
yl]methoxy}-2-methylpropanoate.
ethyl)amino]-2-oxoethoxy}-2-methylpropanoate
Methyl 2-{2-[(2-cyano-
(921 mg,
4.04 mmol) was dissolved in acetonitrile (20 ml). Under a nitrogen
atmosphere, sodium azide (393 mg, 6.05 mmol) and trifluorometh-
anesulfonic anhydride (1.02 ml, 6.05 mmol) were added to the
solution at 0 °C and the resulting mixture was stirred overnight
at room temperature. To the reaction mixture, satd NaHCO3 aq
was added. And the organic materials were extracted with ethyl
acetate. The organic layer was dried over Na2SO4, and then concen-
trated in vacuo. The residue was purified by silica gel column
(ethyl acetate–n-hexane = 1:1) to give the title compound
(221 mg, 0.87 mmol, 22%). 1H NMR (CDCl3) d 1.55 (6H, s), 3.09
(2H, t, J = 7.2 Hz), 3.79 (3H, s), 4.93 (2H, s), 5.01 (2H, t, J = 7.2 Hz).
4.1.1.115. 1-(2-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-2H-1,2,3,4-
tetrazol-5-yl)cyclopropanecarboxylic acid (35j).
Compound
34j (80.9 mg, 0.143 mmol) and potassium carbonate (59.5 mg,
0.43 mmol) were treated, to give the title compound 35j
(70.8 mg, 0.132 mmol, 92%), in a similar manner described for 10.
MS (ESI) m/z 536 (M+H)+. 1H NMR (CDCl3) d 1.26–1.32 (1H, m),
1.36–1.41 (1H, m), 1.67–1.72 (2H, m), 2.57–2.74 (2H, m), 3.42
(3H, s), 3.85 (3H, s), 4.33–4.37 (1H, m), 4.80–4.86 (2H, m), 5.72
(1H, s), 6.26–6.29 (1H, m), 6.33–6.35 (1H, m), 6.69–6.71 (1H, m),
6.94 (1H, d, J = 8.1 Hz), 7.06–7.08 (1H, m), 7.18 (1H, t, J = 8.1 Hz),
7.28–7.35 (3H, m). Anal. Calcd for C27H26N5O5ClÁ2H2OÁ0.075CHCl3:
C, 56.67; H, 5.33; N, 12.10. Found: C, 56.87; H, 4.80; N, 11.61.
4.1.1.121. Methyl 2-[(2-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxy-
phenyl)-4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-2H-
1,2,3,4-tetrazol-5-yl)methoxy]-2-methylpropanoate (35k) and
Methyl
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-1H-1,2,3,4-
tetrazol-5-yl)methoxy]-2-methylpropanoate. Methyl 2-{[1-
2-[(2-{2-[(4R,6S)-8-chloro-6-(2,3-dimethoxyphenyl)-
4.1.1.116. Methyl 2-(allyloxy)-2-methylpropanoate.
Methyl
(2-cyanoethyl)-1H-1,2,3,4-tetrazol-5-yl]methoxy}-2-methylpro-
panoate (221 mg, 0.87 mmol) was dissolved in dichloromethane
(4 ml). To the solution, 1,8-diazabicyclo[5,4,0]undec-7-ene
(0.326 ml, 2.18 mmol) was added at room temperature. The
resulting mixture was stirred overnight at room temperature.
The solution was concentrated to give the crudely purified
methyl 2-methyl-2-(1H-1,2,3,4-tetrazol-5-ylmethoxy)propanoate.
This crude compound and compound 26 (179 mg, 0.37 mmol)
were dissolved in N,N-dimethylformamide (4 ml). To the resulting
solution, potassium carbonate (155 mg, 1.12 mmol) and tetrabu-
tylammonium iodide (138 mg, 0.37 mmol) were added. The result-
ing mixture was stirred at 80 °C for 4 h. The reaction mixture was
diluted with ethyl acetate and washed with brine. The organic
layer was dried over Na2SO4, and then concentrated in vacuo.
The residue was purified by preparative thin layer chromatography
on silica gel (ethyl acetate–n-hexane = 1:2) to give 2H-isomer 34k
(100 mg, 0.17 mmol, 45%) and 1H-isomer (68.9 mg, 0.12 mmol,
31%). 2H-Isomer 34k (low polarity fraction): MS (ESI) m/z 582
(M+H)+. 1H NMR (CDCl3) d 1.51 (6H, d, J = 2.2 Hz), 2.73–2.81 (2H,
m), 3.44 (3H, s), 3.75 (3H, s), 3.86 (3H, s), 4.40–4.44 (1H, m), 4.75
(2H, s), 4.91–4.95 (2H, m), 5.75 (1H, s), 6.32–6.35 (1H, m), 6.38–
6.40 (1H, m), 6.72 (1H, d, J = 2.0 Hz), 6.95–6.98 (1H, m), 7.09–
7.12 (1H, m), 7.21 (1H, t, J = 8.1 Hz), 7.32–7.38 (3H, m). 1H-Isomer
(high polarity fraction): MS (ESI) m/z 582 (M+H)+. 1H NMR (CDCl3)
d 1.45 (6H, d, J = 1.5 Hz), 2.65–2.76 (2H, m), 3.43 (3H, s), 3.65 (3H,
s), 3.76 (2H, s), 3.86 (3H, s), 4.48–4.52 (1H, m), 4.87–4.88 (2H, m),
5.75 (1H, s), 6.31–6.33 (1H, m), 6.37–6.38 (1H, m), 6.74 (1H, d,
J = 2.2 Hz), 6.96 (1H, dd, J = 8.1, 1.5 Hz), 7.10–7.11 (1H, m), 7.18
(1H, t, J = 8.1 Hz), 7.32–7.39 (3H, m).
2-hydroxy-2-methylpropanoate (3.00 g, 25.4 mmol) was treated
by sodium hydride (55% in oil, 1.22 g, 27.9 mmol) and allyl bro-
mide (3.22 ml, 38.1 mmol) to give the title compound (4.02 g,
25.4 mmol, quant.), in a similar manner described for methyl 2,2-
dimethyl-3-(prop-2-yn-1-yloxy)propanoate.
4.1.1.117.
Methyl
2-methyl-2-(2-oxoethoxy)propano-
(3.00 g,
ate.
Methyl 2-(allyloxy)-2-methylpropanoate
19.0 mmol) was dissolved in dichloromethane (60 ml). Ozone
was blown into the resulting solution for 30 min under ice-cooling.
To the reaction mixture, dimethylsulfide (5 ml) was added at
À78 °C. The resulting mixture was warmed slowly to room tem-
perature overnight. The reaction mixture was concentrated in va-
cuo to give the title compound (3.04 g, 18.9 mmol, 99%). 1H NMR
(CDCl3) d 1.49 (6H, s), 3.74 (3H, s), 4.04–4.07 (2H, m), 9.75 (1H, s).
4.1.1.118.
acid.
2-(2-Methoxy-1,1-dimethyl-2-oxoethoxy)acetic
Methyl 2-methyl-2-(2-oxoethoxy)propanoate (3.04 g,
19.0 mmol) was dissolved in a mixture of tert-butanol (30 ml)
and water (30 ml). Under ice-cooling, monosodium phosphate
dihydrate (5.92 g, 37.9 mmol), sulfamic acid (5.52 g, 56.9 mmol)
and sodium chlorite (5.15 g, 56.9 mmol) were added to the result-
ing solution, followed by stirring at room temperature for 30 min.
To the reaction mixture, a 20% aqueous solution of sodium thiosul-
fate was added. The mixture was diluted with chloroform and
washed with brine. The organic layer was dried over Na2SO4, and
then concentrated to give the title compound (1.44 g, 8.17 mmol,
43%). 1H NMR (CDCl3) d 1.50–1.51 (6H, m), 3.77–3.78 (3H, m),
4.10 (2H, s).
4.1.1.122. 2-[(2-{2-[(4R,6S)-8-Chloro-6-(2,3-dimethoxyphenyl)-
4H,6H-pyrrolo[1,2-a][4,1]benzoxazepin-4-yl]ethyl}-2H-1,2,3,4-
4.1.1.119. Methyl 2-{2-[(2-cyanoethyl)amino]-2-oxoethoxy}-2-
methylpropanoate.
2-(2-Methoxy-1,1-dimethyl-2-oxoeth-
tetrazol-5-yl)methoxy]-2-methylpropanoic acid (35k).
Com-

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M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
pound 34k (100 mg, 0.17 mmol) and potassium carbonate (71.3 mg,
0.52 mmol) were treated, to give the title compound 35k (64 mg,
0.11 mmol, 65%), in a similar manner described for 10. MS (ESI) m/z
568 (M+H)+. 1H NMR (CDCl3) d 1.46–1.48 (6H, m), 2.62–2.78 (2H,
m), 3.43 (3H, s), 3.85 (3H, s), 4.38–4.42 (1H, m), 4.72 (2H, s), 4.85–
4.89 (2H, m), 5.73 (1H, s), 6.29–6.31 (1H, m), 6.35–6.37 (1H, m),
6.71 (1H, d, J = 2.0 Hz), 6.94–6.97 (1H, m), 7.08–7.09 (1H, m), 7.19
Radioactivities incorporated (dpm/lg protein) = Radioactivities
of
[
14C]cholesterol (dpm) Â 50,000 (dpm)/radioactivities of
[3H]cholesterol (dpm)/protein content (
lg).
Referring to the mean radioactivity of the cells in the three wells
treated with 0 nM of inhibitors, inhibition (%) of cholesterol synthe-
sis at each concentration was calculated by the following equation:
Inhibition (%) = (1Àarithmetic mean radioactivity incorporated
of three wells at each concentration/arithmetic mean radioactivity
incorporated of three wells at 0 nM) Â 100
(1H, t, J = 7.9 Hz), 7.29–7.37 (3H, m). Anal. Calcd for C28H30
-
N5O6ClÁ1.9H2OÁ0.5EtOHÁ0.1CHCl3: C, 54.84; H, 5.85; N, 10.99. Found:
C, 55.23; H, 5.21; N, 10.52.
4.3. Rat single-dose in vivo hepatic cholesterol synthesis
inhibitory activity
4.2. Biological evaluation procedure of inhibitory effects on
cholesterol synthesis in rat hepatic cell
A rat single-dose liver-cholesterol synthesis inhibitory effect
was measured as described below.
4.2.1. Preparation of rat primary hepatocytes
To each the compounds of the present invention was added a
necessary amount of a 0.5% methyl cellulose solution immediately
before use. Then, an equivalent molar amount of sodium hydroxide
or sodium hydrogen carbonate was added to dissolve or suspend it
in the resulting solution. To 6-week-old Wistar male rats were or-
ally administered each of the compounds of the present invention
(3 mg/kg, n = 4–6), while only a 0.5% methyl cellulose solution
was administered to a control group. One hour later, physiological
Shechter’s method10 was slightly modified. This study consisted
of three experiments, and the effects of inhibitors at each concen-
tration were evaluated in triplicate. One animal was used to pre-
pare the hepatocytes for each experiment.
Under anesthesia by thiopental sodium (0.1 g/kg, ip), a plastic
catheter was introduced through the portal vein. The liver was per-
fused with Ca2+, Mg2+ free Hanks’ balanced salts solution (pH 7.2)
containing 2% albumin, 0.5 mM EGTA, 10 mM HEPES, and
41.7 mM NaHCO3 at 37 °C for 10 min at 19–21 ml/min; and then
with Ca2+, Mg2+ free Hanks’ balanced salts solution (pH 7.5) con-
taining 0.05% collagenase, 4 mM CaCl2, 10 mM HEPES, and
41.7 mM NaHCO3 for another 15 min. Liver cells were dispersed
saline of mevalonic acid (5 lCi/5 ml/kg) labeled with a radioisotope
14C was intraperitoneally administered. The rats were sacrificed 1 h
later. To 1 g of the liver thus obtained from the rats was added 5 ml
of a 15% KOH ethanol solution and the resulting mixture was left to
stand for 15 h. After heating at 75 °C for 2 h, the reaction mixture
was extracted with 5 ml of water and 10 ml of petroleum ether.
The petroleum ether layer was collected, evaporated to dryness
in DMEM supplemented with 100 U/ml penicillin and 100
streptomycin by dissection and gentle pipetting. After filtration
through a 70 m nylon mesh filter (Cell Strainer, BD Falcon), hepa-
lg/ml
l
and then dissolved in 50 ll of a chloroform/acetone = 2:1 solution.
tocytes were obtained by repeated centrifugation (3 times) at
600 rpm (centrifuge; 5930, swinging bucket rotor: RS-3011M) for
1 min at 4 °C. After the last centrifugation, the medium was chan-
ged to DMEM supplemented with 10% LPDS, 100 U/ml penicillin,
The cholesterol band was separated by silica gel thin layer chroma-
tography (Art.5748, toluene/ethyl acetate = 3:1) and cut out. It was
put in a vial container, followed by the addition of 10 ml of Aquasol-
2 (product of Packard BioScience Company). The radioactivity was
measured using a liquid scintillation counter. A ratio of the radioac-
tivity relative to that of a control group was determined and liver-
cholesterol synthesis inhibitory activity (%) was calculated.
and 100 lg/ml streptomycin. Then, viability was determined by
staining with trypan blue. Hepatocytes with over 80% viability
were cultured in 6-well cell culture plates (106 cells/well).
4.2.2. Measurement of cholesterol biosynthetic activity of rat
hepatocytes
4.4. Plasma lipid lowering studies in common marmosets
One day later, the medium was replaced with media supple-
mented with 5% LPDS, 25 mM HEPES, and inhibitors (final concen-
trations: 0, 1, 3, 10, 30, 100, 300, 1000, and 3000 nM). After
Male and female common marmosets (305–410 g) were pur-
chased from Clea Japan (Tokyo, Japan), and fed a commercial chow
diet (CMS-1M; Clea Japan) and allowed access to water ad libitum.
All animal experiments were carried out according to the Daiichi
Sankyo Animal Care Guidelines.
Before the experiment, blood samples were collected under
nonfasted conditions. Plasma total cholesterol and triglyceride
were measured as described above. High-density lipoprotein
(HDL) was separated by precipitation reagents (Wako Pure Chem-
ical Industries). And then the cholesterol was measured enzymat-
ically. Non-HDL-cholesterol was calculated by subtracting HDL-
cholesterol from total cholesterol.
incubation for 1 h at 37 °C, 10 l lCi/
l of [14C]mevalonolactone (5
ml) was added into the media, and the incubation was continued
for another 1 h. The cells were washed with D-PBS (3 times) and
dissolved in 1 ml of 0.1 M NaOH. Ten micro liters of the cell lysates
were transferred to a 96-well plate to determine the protein con-
centration in duplicate. Eight hundred microliters of the remains
were saponified for 1 h at 75 °C by adding 2 ml of ethanol and
0.5 ml of 50 (w/v)% KOH. After the addition of 50 or 100
ll of
[3H]cholesterol (0.45
lCi/ml) as an internal standard, the nonsa-
ponifiable lipids were extracted with 4.5 ml of petroleum ether.
Water layer was frozen in dry ice and ethanol, and the upper layer
was transferred to another tube. The extracts in the tubes were
Common marmosets were divided into two groups (control vs
prepared compound, 100 mg/kg, n = 8); groups were matched for
body weight, plasma total cholesterol, triglyceride, HDL cholesterol
and non-HDL cholesterol. Drugs were suspended in 0.5% methyl-
cellulose solution and administered orally at 5 ml/kg once a day
(9–10AM) for 7 days. Next morning after the final administration
of drugs, blood samples were collected under nonfasted conditions
and plasma parameters were measured.
dried under N2 gas at 40 °C. The residue was dissolved in 50 ll of
dichloromethane–methanol (2:1) solution including 10 mg/ml
cholesterol, applied onto TLC plastic sheets (Silica gel 60), and
developed with a solvent (toluene–ethyl acetate, 3:1). The radio
activities incorporated into the cholesterol fractions in Aquasol-2
were counted with a liquid scintillation counter.
The protein concentration was determined using a BCA Protein
Assay Kit.
Acknowledgments
The radioactivities incorporated into the cholesterol fractions
were corrected from the formula as follows:
We thank the members of Cardiovascular-Metabolics Research
Laboratories for the biological assays, and Daiichi Sankyo RD

M. Ichikawa et al. / Bioorg. Med. Chem. 20 (2012) 3072–3093
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