Indoline derivatives I: Synthesis and Factor Xa (FXa) inhibitory activities

Article abstract of DOI:10.1248/cpb.54.163

A series of bisamidine derivatives each having a ring structure in the center of the molecule was synthesized and their Factor Xa (FXa) inhibitory activities were evaluated. Among them, some indoline derivatives showed potent inhibitory activities in vitr

Full text of DOI:10.1248/cpb.54.163

February 2006
Chem. Pharm. Bull. 54(2) 163—174 (2006)
163
Indoline Derivatives I: Synthesis and Factor Xa (FXa) Inhibitory
Activities
Tetsuji NOGUCHI,a Naoki TANAKA,*,a Toyoki NISHIMATA,a Riki GOTO,a Miho HAYAKAWA,a
c
a,1)
Atsuhiro SUGIDACHI,b Taketoshi OGAWA,b Fumitoshi ASAI,b Yumi MATSUI, and Koichi FUJIMOTO
a Medicinal Chemistry Research Laboratories, Sankyo Co., Ltd.; b Pharmacology and Molecular Biology Research
Laboratories, Sankyo Co., Ltd.; and c Core Technology Research Laboratories, Sankyo Co., Ltd.; 1–2–58 Hiromachi,
Shinagawa-ku, Tokyo 140–8710, Japan. Received August 2, 2005; accepted November 5, 2005
A series of bisamidine derivatives each having a ring structure in the center of the molecule was synthesized
and their Factor Xa (FXa) inhibitory activities were evaluated. Among them, some indoline derivatives showed
potent inhibitory activities in vitro. In particular, (R)-18a having an (R)-configuration at the 2-position of the in-
doline ring exhibited the most potent FXa inhibitory activity in vitro, more potent than DX-9065a. Furthermore,
(R)-18a exhibited more potent anticoagulant activity than DX-9065a. We also succeeded in obtaining an X-ray
crystal structure of FXa bound with (R)-18a.
Key words Facter Xa (FXa) inhibitory activity; indoline derivative; anticoagulant
the FXa active site.14)
Factor Xa (FXa), a serine protease in the blood coagula-
tion cascade,2) is essential for the formation of thrombin, a
Thus, introduction of a cyclic moiety in the center of these
structures was expected to increase the rigidity of the mole-
cule and enhance affinity towards FXa. Using this strategy,
we synthesized indoline compounds and their derivatives to
find compounds which bind tightly to the active FXa site.
In this paper, we describe the synthesis and structure–ac-
tivity relationships (SARs) of these compounds and the X-
ray crystal structure of one of these compound bound to FXa.
key mediator of both fibrin formation and platelet activation.
FXa plays an important role in the coagulation network at the
common pathway that connects both the tissue factor-acti-
vated extrinsic pathway and the surface-activated intrinsic
pathway. Inactivation of FXa does not influence preformed
thrombin but does effectively prevent the generation of
thrombin.3,4) Thus, FXa inhibitors are expected to be novel
antithrombotics with potential for the treatment and preven-
tion of thromboembolic diseases without risk of bleeding.5)
Several antithrombotic agents, low molecular weight he-
parins6) and synthetic pentasaccharide fondaparinux sodium
(Arixtra7)), targeted to FXa, are known. These agents require
antithrombin III (ATIII), variable from patient to patient, to
produce antithrombotic effects. Some studies showed that
ATIII-dependent agents were less potent toward clot-bound
coagulation factors compared with coagulation enzymes pre-
sent in the plasma because of a lower accessibility of agent-
ATIII complexes to the clot-bound coagulation factors.8,9)
Therefore, small molecule FXa inhibitors which produce an-
ticoagulant action independent of ATIII are thought to be
more promising anticoagulants than ATIII-dependent antico-
agulants.10)
Chemistry
Key intermediates 9a—j were synthesized as shown in
Chart 1. Protected nitrophenol 1 was introduced a trimeth-
ylsilylmethyl group to give compound 2.15) Compound 2
was coupled with 2-cyano-7-naphthylaldehyde (3)16) by tetra-
butylammonium fluoride (TBAF) to give alcohol 4. After
reduction of the nitro group of 4 by catalytic hydrogenation,
aniline 5 was reacted with ethanesulfonyl chloride under
basic conditions to give sulfonamide 6. Intramolecular Mi-
tsunobu reaction17) of 6 with n-Bu3P and 1,1ꢀ-(azodicar-
bonyl)dipiperidine (ADDP) afforded corresponding indoline
7. After removing the methoxymethyl (MOM) group of 7 by
treatment with HCl, phenol 8 was converted to intermediates
9a—j by means of the Mitsunobu reaction with alcohols
(method A), or by alkylation with the tosylate (method B).
Intermediates 16a and 16b were synthesized as shown in
Chart 2. 1-Fluoro-4-nitrobenzene (10) was converted to ether
11a and 11b by reaction with alcohols. Compounds 11a and
11b were subjected to the similar procedures as Chart 1 to
give the corresponding intermediates 16a and 16b.
Many direct FXa inhibitors have been reported in the liter-
ature. Among them, we focused on the structure of DX-
9065a11,12) and Yamanouchi compound13) (Fig. 1) which have
amidino groups on each side of the molecules and side
chains in the center of the molecules. Moreover, this moiety
seems to have weak rigidity and results in loose binding to
The syntheses of the amidine derivatives from intermedi-
ates 9a—j are outlined in Chart 3. Compounds 9a—j were
converted to the corresponding amidines 17a—j by bubbling
HCl gas into an alcohol solution of nitriles, followed by ami-
nation of the resulting imidates (method C), or by treatment
with hydroxylamine, followed by acetylation and hydrogena-
tion of the resulting amidoximes (method D). The treatment
of 17a, f—j having the non-substituted amine moieties with
ethyl acetimidate and triethylamine afforded corresponding
bisamidines 18a, f—j.
Fig. 1. Structures of DX-9065a, Yamanouchi Compound and Indoline De-
rivative
The synthesis of compound 21 is outlined in Chart 4. After
∗ To whom correspondence should be addressed. e-mail: naokit@sankyo.co.jp
© 2006 Pharmaceutical Society of Japan

164
Vol. 54, No. 2
Chart 1
Chart 2
Chart 3
removing the t-butoxycarbonyl (Boc) group of 16a under After aldol reaction of aldehyde 23 and ketone 24, the result-
acidic conditions, compound 19 was converted into acetimi- ing alcohol was treated with acid, followed by reprotection of
date 20. Compound 21 was synthesized from 20 by the same the phenolic hydroxyl group to give unsaturated ketone 25.
method (method C) described above.
Reduction of the carbonyl group of 25, followed by hydro-
Tetrahydroquinoline derivative 30 was synthesized as genation of alcohol 26 afforded aniline 27. Compound 27
shown in Chart 5. Phenol 22 was protected to give compound was converted to the corresponding sulfonamide 28, which
23, and aldehyde 3 was converted to ketone 24 in 2 steps. was cyclized by means of intramolecular Mitsunobu reaction

February 2006
165
Chart 4
Chart 5
Chart 6
to give tetrahydroquinoline 29. Compound 30 was synthe- tive indoline moiety was confirmed by X-ray crystallographic
sized from 29 by the same methods (methods A and D) de- analysis of (R)-9a (Fig. 2).
scribed above.
Non-substituted indoline derivative 32 and indole deriva- Results and Discussion
tives 33 and 35 were synthesized as shown in Chart 6. The
benzyloxycarbonyl (Z) group of intermediate 16b was re- synthesized were evaluated and are expressed as IC50 values.
moved to give compound 31 and this compound was con- As described above, we considered that introduction of the
The in vitro FXa inhibitory activities of all compounds
verted to the corresponding non-substituted indoline com- ring structure into the center of the molecule to enhance
pound 32 and indole compound 33, an oxidized form of 32 rigidity would give higher FXa inhibitory activity. So we
by the similar procedures described above. Moreover, com- studied the influence of the ring structure (Table 1). Regard-
pound 31 was oxidized by MnO2,18) followed by treatment ing the indoline compounds, compound 18a having an
with ethanesulfonyl chloride to give compound 34 having an ethanesulfonyl moiety on the nitrogen atom exhibited more
ethanesulfonyl group on the indole ring. Compound 34 was potent FXa inhibitory activity than no-substituent compound
converted to the corresponding ethanesulfonylindole 35 by 32. This tendency was also observed for the indole com-
the same procedures as above.
pounds (35 vs. 33). Regarding the ring structure, indoline
The syntheses of optically active (R)-18a and (S)-18a are compound 18a exhibited much higher FXa inhibitory activ-
outlined in Chart 7. Racemic alcohol 5 was separated by chi- ity than indole compound 35. Moreover, indoline compound
ral column chromatography into optically pure (S)-5 and (R)- 18a exhibited 5-fold higher FXa inhibitory activity than that
5, respectively. After reaction of (S) and (R)-5 with ethane- of tetrahydroquinoline compound 30. Among these ring
sulfonyl chloride, ether (R) and (S)-9a, respectively, were ob- structures, the indoline structure having a substituent was
tained via stereochemically inversed indoline (R) and (S)-7, found to be suitable as the center of the molecule.
respectively, by the same procedure as that for 9a. Optically
Next, the effect of the substituent on the nitrogen atom of
active bisamidines (R)-18a and (S)-18a were synthesized the piperidine ring was examined (Table 2). No-substituent
from (R) and (S)-9a, respectively, by the same method as de- compound 17a and 2-pyridyl compound 17b had signifi-
scribed in Chart 3. The stereochemistry of the optically ac- cantly (11-fold) low inhibitory activity compared to the ace-

166
Vol. 54, No. 2
Chart 7
Table 2. FXa Inhibitory Activity of Compounds 18a and 17a—e
Compd.a)
R
IC50 (nM)
18a
17a
17b
11
120
120
17c
17d
29
53
Fig. 2. View of the (R)-9a Molecule
H atoms have been omitted for clarity.
17e
34
Table 1. FXa Inhibitory Activity of Compounds 18a, 32, 35, 33 and 30
a) All compounds were synthesized and evaluated as their hydrochlorides.
timidoyl compound 18a. Regarding the acyl-type com-
pounds, urea compound 17c, glycyl compound 17d, and
acetyl compound 17e were tested. Among them, 17c and 17e
exhibited moderate activity, but lower than that of 18a. These
results indicate that an acetimidoyl group is favorable as a
substituent on the nitrogen atom of the piperidine ring.
Compd.a)
L
IC50 (nM)
11
18a
To further optimize this basic moiety, we focused on the
amine structure attached to the acetimidoyl group (Table 3).
In regard to ring size, 4-piperdine compound 18a showed po-
tent inhibitory activity similar to that of 3-pyrrolidine com-
pound 18f having the same moiety as DX-9065a, whereas 3-
azetidine compound 21 exhibited weak activity. Introduction
of one carbon atom between the piperidine ring and the oxy-
gen atom decreased FXa inhibitory activity (18a vs. 18g). A
compound substituted at the 3-position of the piperidine ring
(18h) showed 3-fold less inhibitory activity compared to that
at the 4-position (18a). On the other hand, introduction of an
acyclic amine structure (18i, j) instead of the piperidine ring
resulted in a decline of inhibitory activity. According to these
results, a 4-piperidine or 3-pyrrolidine moiety turned out to
be the most appropriate as the amine structure. However, we
32
35
33
30
180
3600
7100
51
a) All compounds were synthesized and evaluated as their hydrochlorides.

February 2006
167
thought that 18a was more favorable than 18f because 18a
To further understand the SARs of these compounds, the
has no asymmetric carbon on the ring structure.
crystal structure of FXa complexed with (R)-18a was deter-
All indoline derivatives discussed above are racemates mined by X-ray crystallography at 2.3 Å resolution (Fig. 3).
having an asymmetric carbon atom at the 2-position of the The crystal structure revealed that (R)-18a binds to FXa in an
indoline ring. Therefore, each of the enantiomers of 18a was L-shaped conformation with the naphthamidine moiety deep
prepared to examine their FXa inhibitory activities (Table 4). in the S1 pocket and the acetimidoylpiperidine moiety at the
The compound with the (R)-configuration, (R)-18a, exhibited aryl binding site consisting of residues Tyr-99, Phe-174 and
20-fold higher inhibitory activity than that with the (S)-con- Trp-215. Indole compound 35, having an sp2 carbon atom
figuration, (S)-18a. The result indicates that (R)-18a is the corresponding to the asymmetric carbon atom at the 2-posi-
active enantiomer for FXa inhibitory activity. We compared tion of the indoline ring in (R)-18a, has a relatively flat struc-
this activity to that of DX-9065a which is in clinical trial at ture and does not form the L-shaped conformation peculiar
present. (R)-18a showed more potent activity than that of to (R)-18a. Therefore, the surface of 35 would not be com-
DX-9065a.
plementary to that of FXa. The crystal structure shows that
(R)-18a binds to FXa in an L-shaped conformation with
good surface complementarity, resulting in much higher FXa
inhibitory activity of (R)-18a than that of 35.
Table 3. FXa Inhibitory Activity of Compounds 18a—f and 21
Moreover, the complex structure of FXa and (R)-18a was
compared to that of FXa and DX-9065a14) in order to under-
stand the difference in FXa inhibitory activity (Table 4). DX-
9065a binds to FXa in a similar L-shaped conformation to
that of (R)-18a, with the naphthylamidine moiety in the S1
pocket and the pyrrolidine moiety at the aryl binding site
(Fig. 3). However, there are two remarkable differences be-
tween these two compounds. First, although the terminal ace-
timidoyl group of DX-9065a points to Glu-97, the acetimi-
Compd.a)
18a
R
IC50 (nM)
11
17
18fb)
21
43
31
34
71
61
Table 4. FXa Inhibitory Activity of Compounds (RS)-18a, (R)-18a, (S)-
18a and DX-9065a
18g
18hb)
18i
Compd.a)
IC50 (nM)
(RS)-18a
(R)-18a
(S)-18a
11
7.6
150
64
18j
DX-9065a
a) All compounds were synthesized and evaluated as their hydrochlorides. b) A
mixture of four diastereoisomers.
a) All compounds were synthesized and evaluated as their hydrochlorides.
Fig. 3. Stereoview of Binding Mode of (R)-18a with FXa
The structure of FXa complexed with (R)-18a is shown in stick representation. Water molecules are represented as red balls. Where the complex structure of FXa and DX-9065a
is superposed on that of FXa and (R)-18a, only DX-9065a is shown in stick representation. The color scheme is as follows: nitrogen atoms, blue; oxygen atoms, red; sulfur atoms,
yellow; carbon atoms of (R)-18a, cyan; carbon atoms of DX-9065a, orange; carbon atoms of Asp-189 (in S1 pocket), Tyr-99, Phe-174 and Trp-215 (at the aryl binding site), ma-
genta; and other carbon atoms of FXa, green.

168
Vol. 54, No. 2
doyl group of (R)-18a extends to the space between Thr-98 each having a ring structure in the center of the molecule and
and Ile-175, contributing to the good surface complementar- evaluated their FXa inhibitory activities. According to the re-
ity of (R)-18a. Secondly, the carboxyl group of DX-9065a sults, we found that some novel indoline derivatives have
between the S1 pocket and the aryl binding site makes a hy- high FXa inhibitory activities. Among them, (R)-18a, having
drogen bond with Gln-192 with a length of 3.1 Å, while the an (R)-configuration at the 2-position of the indoline ring, ex-
ethanesulfonyl group of (R)-18a makes a hydrogen bond hibited more potent FXa inhibitory activity and anticoagulant
with Gly-218 with a length of 2.9 Å, a more optimum length activity than those of DX-9065a in vitro. (R)-18a and some
for a hydrogen bond. The comparison of the complex struc- indoline derivatives are currently under further evaluation
tures suggests that these conformational differences likely and we are continuing synthetic efforts to explore novel com-
contribute to the higher FXa inhibitory activity of (R)-18a pounds having more potent FXa inhibitory activity and
than that of DX-9065a.
safety.
We evaluated the effect of the anticoagulant activity of
(R)-18a on prothrombin time (PT) and expressed it as a CT2
value, the concentration required to achieve 200% relative
clotting time. Table 5 shows the CT2 values of (R)-18a and
DX-9065a in hamsters and humans (in vitro). (R)-18a exhib-
ited potent anticoagulant activity and its activity was much
higher than that of DX-9065a in both hamsters and humans.
In conclusion, we synthesized many bisamidine derivatives
Experimental
1H-NMR spectra were obtained on a JEOL EX 270 or 400 MHz spectrom-
eter and were reported as d values relative to Me4Si as the internal standard.
Abbreviations of the 1H-NMR peak patterns are as follows: br sꢁbroad sin-
glet, sꢁsinglet, dꢁdoublet, ddꢁdouble doublet, tꢁtriplet, br tꢁbroad triplet,
qꢁquartet, and mꢁmultiplet. Merck Silica gel 60 (230—400 mesh) was
used in the column chromatography. Tetrahydrofuran, N,N-dimethylfor-
mamide, N,N-dimethylacetamide, and dimethylsulfoxide are abbreviated as
THF, DMF, DMA and DMSO, respectively.
4-(Methoxymethoxy)-1-nitro-2-(trimethylsilylmethyl)benzene (2) To
a solution of 4-(methoxymethoxy)-1-nitrobenzene 1 (41.9 g, 229 mmol) in
THF (50 ml) was slowly added (trimethylsilylmethyl)magnesium chloride
(1.0 M in Et2O, 252 ml, 252 mmol) and the mixture was stirred at ꢂ30 °C for
Table 5. Anticoagulant Activity of Compounds (R)-18a and DX-9065a
CT2 (mM)a)
Compd.
30 min. Then
a solution of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone
Hamster
Human
(DDQ) (52 g, 229 mmol) in THF (300 ml) was added slowly and the mixture
was stirred at ꢂ30 °C for 2 h. The mixture was concentrated and the result-
ing residue was dissolved in EtOAc. The mixture was filtered through a sil-
ica gel column and the filtrate was concentrated. The resulting residue was
chromatographed on a silica gel column (hexane/EtOAcꢁ5/1) to give 2
(R)-18a
DX-9065a
1.1
8.3
0.52
2.7
a) The concentration required to double clotting time (PT).
1
(45.9 g, 170 mmol, 74%) as an oil. H-NMR (CDCl3) d: 0.01 (9H, s), 2.64
Table 6. Physical Data for Indoline Derivatives
Analysis (%), Calcd (Found)
Compd.
Formula
C
H
N
Cl
S
17a
17b
17c
17d
17e
18a
18f
18g
18h
18i
18j
21
C26H30N4O3S·1.9HCl·2.5H2O
C31H33N5O3S·2.5HCl·1.0H2O
C27H31N5O4S·1.7HCl·1.4H2O
C28H33N5O4S·2.0HCl·1.3H2O
C28H32N4O4S·1.0HCl·1.0H2O
C28H33N5O3S·2.3HCl·1.3H2O
C27H31N5O3S·2.6HCl·2.2H2O
C29H35N5O3S·2.0HCl·1.2H2O
C28H33N5O3S·2.0HCl·1.2H2O
C27H33N5O3S·2.1HCl·2.7H2O
C28H35N5O3S·1.9HCl·2.5H2O
C26H29N5O3S·2.0HCl·1.9H2O
C29H35N5O3S·2.0HCl·2.0H2O
C26H29N5O·3.3HCl·3.9H2O
C26H27N5O·2.0HCl·2.3H2O
C28H31N5O3S·2.0HCl·3.4H2O
52.67
(52.90)
56.00
(56.19)
53.26
(53.57)
53.21
(52.95)
58.48
(58.23)
53.64
(53.59)
50.67
(50.32)
55.44
(55.19)
54.76
(54.68)
51.24
(51.20)
52.88
(53.00)
52.16
(52.01)
54.20
(54.05)
50.52
(50.65)
57.84
(57.82)
51.60
6.27
(5.96)
5.69
(5.67)
5.88
(5.99)
6.00
(5.95)
6.13
(5.98)
6.09
(6.04)
5.98
(6.08)
6.32
(6.56)
6.14
(6.40)
6.45
(6.10)
6.64
(6.35)
5.86
(5.59)
6.43
(6.44)
6.54
(6.41)
6.27
(6.36)
6.15
9.45
(9.13)
10.53
(10.33)
11.50
(11.25)
11.08
(10.75)
9.74
(9.44)
11.17
(11.09)
10.94
(11.17)
11.15
(11.07)
11.40
(11.38)
11.07
(11.20)
11.01
(11.22)
11.70
(11.86)
10.90
(10.75)
11.33
(11.29)
12.97
(12.71)
10.74
11.36
(11.62)
13.33
(13.22)
9.90
(9.85)
11.22
(11.56)
6.16
(6.60)
13.01
(13.31)
14.40
(14.68)
11.29
(11.66)
11.54
(11.82)
11.76
(11.83)
10.59
(10.47)
11.84
(12.29)
11.03
(11.41)
18.93
(19.21)
13.13
(13.21)
10.88
5.41
(5.09)
4.82
(4.73)
5.27
(5.15)
5.07
(5.47)
5.58
(5.36)
5.11
(5.05)
5.01
(5.05)
5.10
(5.08)
5.22
(5.05)
5.07
(5.10)
5.04
(5.05)
5.35
(5.39)
4.99
30
(5.15)
—
32
33
—
35
4.92
(51.53)
(5.78)
(10.55)
(11.10)
(4.99)

February 2006
169
Table 7. Physical Data for Indoline Derivatives
Compd.
1H-NMR d (DMSO-d6)
17a
17b
17c
1.18 (3H, t, Jꢁ7.5 Hz), 1.74—1.90 (2H, m), 2.04—2.15 (2H, m), 2.95—3.37 (7H, m), 3.96 (1H, dd, Jꢁ10.0, 17.0 Hz), 4.50—4.61
(1H, m), 5.78 (1H, dd, Jꢁ2.5, 10.0 Hz), 6.92 (1H, dd, Jꢁ2.5, 9.0 Hz), 6.99 (1H, br s), 7.34 (1H, d, Jꢁ9.0 Hz), 7.64 (1H, dd, Jꢁ1.5,
8.5 Hz), 7.83 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.96 (1H, br s), 8.08 (1H, d, Jꢁ8.5 Hz), 8.13 (1H, d, Jꢁ8.5 Hz), 8.50 (1H, br s)
1.19 (3H, t, Jꢁ7.5 Hz), 1.64—1.84 (2H, m), 2.00—2.16 (2H, m), 2.96—3.37 (3H, m), 3.62—3.78 (2H, m), 3.89—4.12 (3H, m),
4.58—4.72 (1H, m), 5.73—5.85 (1H, m), 6.88—7.05 (3H, m), 7.36 (1H, d, Jꢁ8.5 Hz), 7.38—7.49 (1H, m), 7.61—7.71 (1H, m),
7.81—7.91 (1H, m), 7.94—8.19 (5H, m), 8.52 (1H, br s)
1.18 (3H, t, Jꢁ7.5 Hz), 1.35—1.55 (2H, m), 1.79—1.94 (2H, m), 2.94—3.37 (5H, m), 3.58—3.73 (2H, m), 3.95 (1H, dd, Jꢁ10.5,
17.0 Hz), 4.37—4.50 (1H, m), 5.77 (1H, dd, Jꢁ2.5, 10.0 Hz), 6.88 (1H, dd, Jꢁ2.5, 9.0 Hz), 6.95 (1H, d, Jꢁ2.5 Hz), 7.33 (1H, d,
Jꢁ9.0 Hz), 7.65 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.82 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.95 (1H, br s), 8.08 (1H, d, Jꢁ8.5 Hz), 8.13 (1H, d,
Jꢁ8.5 Hz), 8.49 (1H, br s)
17d
17e
1.19 (3H, t, Jꢁ7.5 Hz), 1.41—1.67 (2H, m), 1.82—2.02 (2H, m), 2.94—4.04 (10H, m), 4.45—4.65 (1H, m), 5.72—5.82 (1H, m),
6.86—7.00 (2H, m), 7.34 (1H, d, Jꢁ8.5 Hz), 7.60—7.69 (1H, m), 7.78—7.88 (1H, m), 7.96 (1H, br s), 8.07 (1H, d, Jꢁ8.5 Hz), 8.13
(1H, d, Jꢁ8.5 Hz), 8.49 (1H, br s)
1.18 (3H, t, Jꢁ7.5 Hz), 1.35—1.66 (2H, m), 1.77—2.04 (2H, m), 2.00 (3H, s), 3.00 (1H, dd, Jꢁ2.5, 17.0 Hz), 3.06—3.38 (4H, m),
3.57—4.09 (2H, m), 3.95 (1H, dd, Jꢁ10.0, 17.0 Hz), 4.45—4.57 (1H, m), 5.77 (1H, dd, Jꢁ2.5, 10.0 Hz), 6.90 (1H, dd, Jꢁ2.5,
8.5 Hz), 6.93 (1H, br s), 7.33 (1H, d, Jꢁ8.5 Hz), 7.65 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.82 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.96 (1H, br s),
8.08 (1H, d, Jꢁ8.5 Hz), 8.13 (1H, d, Jꢁ8.5 Hz), 8.49 (1H, br s)
18a
1.18 (3H, t, Jꢁ7.5 Hz), 1.63—1.83 (2H, m), 1.93—2.14 (2H, m), 2.29 (3H, s), 3.02 (1H, dd, Jꢁ2.5, 17.0 Hz), 3.07—3.18 (1H, m),
3.25—3.41 (1H, m), 3.45—3.62 (2H, m), 3.67—3.87 (2H, m), 3.96 (1H, dd, Jꢁ10.0, 17.0 Hz), 4.57—4.68 (1H, m), 5.78 (1H, dd,
Jꢁ2.5, 10.0 Hz), 6.92 (1H, dd, Jꢁ2.5, 9.0 Hz), 6.99 (1H, d, Jꢁ2.0 Hz), 7.35 (1H, d, Jꢁ9.0 Hz), 7.64 (1H, d, Jꢁ8.5 Hz), 7.84 (1H, dd,
Jꢁ2.0, 8.5 Hz), 7.96 (1H, br s), 8.08 (1H, d, Jꢁ8.5 Hz), 8.13 (1H, d, Jꢁ8.5 Hz), 8.50 (1H, br s)
18f
18g
18h
18i
1.19 (3H, t, Jꢁ7.5 Hz), 2.14—2.33 (2H, m), 2.25, 2.29 (together 3H, each singlet), 2.94—3.20 (2H, m), 3.34—4.03 (6H, m), 5.05—
5.21 (1H, m), 5.73—5.84 (1H, m), 6.84—7.00 (2H, m), 7.30—7.41 (1H, m), 7.58—7.69 (1H, m), 7.76—7.87 (1H, m), 7.96 (1H,
br s), 8.08 (1H, d, Jꢁ8.5 Hz), 8.13 (1H, d, Jꢁ8.5 Hz), 8.49 (1H, br s)
1.18 (3H, t, Jꢁ7.5 Hz), 1.25—1.50 (2H, m), 1.80—1.95 (2H, m), 2.03—2.21 (1H, m), 2.29 (3H, s), 2.94—3.45 (5H, m), 3.82 (2H, d,
Jꢁ6.0 Hz), 3.87—4.04 (2H, m), 4.11—4.26 (1H, m), 5.73—5.84 (1H, m), 6.82—6.95 (2H, m), 7.34 (1H, d, Jꢁ8.5 Hz), 7.59—7.69
(1H, m), 7.80—7.89 (1H, m), 7.95 (1H, br s), 8.07 (1H, d, Jꢁ8.5 Hz), 8.13 (1H, d, Jꢁ8.5 Hz), 8.50 (1H, br s)
1.11—1.25 (3H, m), 1.51—2.00 (4H, m), 2.19, 2.33 (together 3H, each singlet), 2.93—4.05 (8H, m), 4.50—4.69 (1H, m), 5.74—
5.86 (1H, m), 6.85—7.01 (2H, m), 7.30—7.41 (1H, m), 7.57—7.69 (1H, m), 7.78—7.90 (1H, m), 7.95 (1H, br s), 8.08 (1H, d,
Jꢁ8.5 Hz), 8.13 (1H, d, Jꢁ8.5 Hz), 8.51 (1H, br s)
1.18 (3H, t, Jꢁ7.3 Hz), 1.94—2.09 (2H, m), 2.25, 2.27 (together 3H, each singlet), 2.97—3.02 (1H, m), 3.04, 3.12 (together 3H,
each singlet), 3.07—3.17 (2H, m), 3.23—3.34 (2H, m), 3.59 (2H, br t, Jꢁ6.3 Hz), 3.91—4.05 (3H, m), 5.78 (1H, dd, Jꢁ2.5, 9.9 Hz),
6.85—6.89 (1H, m), 6.92 (1H, d, Jꢁ2.8 Hz), 7.35 (1H, d, Jꢁ8.7 Hz), 7.63 (1H, dd, Jꢁ1.6, 10.1 Hz), 7.84 (1H, dd, Jꢁ1.6, 8.7 Hz),
7.95 (1H, s), 8.07 (1H, d, Jꢁ8.7 Hz), 8.12 (1H, d, Jꢁ8.7 Hz), 8.50 (1H, s)
18j
21
1.18 (3H, t, Jꢁ7.4 Hz), 1.61—1.78 (4H, br s), 2.24, 2.28 (together 3H, each singlet), 3.01 (1H, dd, Jꢁ1.7, 17.0 Hz), 3.04, 3.11 (to
gether 3H, each singlet), 3.11 (1H, dd, Jꢁ7.3, 14.2 Hz), 3.22—3.40 (1H, m), 3.44—3.53 (2H, m), 3.90—4.02 (3H, m), 5.78 (1H, dd,
Jꢁ2.5, 10.0 Hz), 6.86 (1H, dd, Jꢁ2.5, 8.8 Hz), 6.91 (1H, s), 7.34 (1H, d, Jꢁ8.8 Hz), 7.64 (1H, d, Jꢁ8.6 Hz), 7.84 (1H, dd, Jꢁ1.8,
8.6 Hz), 7.95 (1H, s), 8.07 (1H, d, Jꢁ8.7 Hz), 8.12 (1H, d, Jꢁ8.7 Hz), 8.51 (1H, s)
1.18 (3H, t, Jꢁ7.5 Hz), 2.08, 2.09 (together 3H, each singlet), 3.02 (1H, d, Jꢁ17.0 Hz), 3.07—3.19 (1H, m), 3.24—3.42 (1H, m),
3.97 (1H, dd, Jꢁ10.0, 17.0 Hz), 4.03—4.14 (1H, m), 4.28—4.37 (1H, m), 4.56—4.66 (1H, m), 4.69—4.79 (1H, m), 5.02—5.13 (1H,
m), 5.80 (1H, dd, Jꢁ2.5, 10.0 Hz), 6.81 (1H, dd, Jꢁ2.5, 9.0 Hz), 6.87 (1H, br s), 7.38 (1H, d, Jꢁ9.0 Hz), 7.63 (1H, dd, Jꢁ1.5,
8.5 Hz), 7.84 (1H, dd, Jꢁ2.0, 8.5 Hz), 7.95 (1H, br s), 8.08 (1H, d, Jꢁ8.5 Hz), 8.13 (1H, d, Jꢁ8.5 Hz), 8.51 (1H, br s)
1.17 (3H, t, Jꢁ7.5 Hz), 1.64—1.82 (2H, m), 1.88—2.12 (3H, m), 2.30 (3H, s), 2.52—2.69 (2H, m), 2.72—2.84 (1H, m), 2.99—3.13
(1H, m), 3.28—3.43 (1H, m), 3.45—3.62 (2H, m), 3.65—3.90 (2H, m), 4.61—4.72 (1H, m), 5.61 (1H, t, Jꢁ7.0 Hz), 6.86 (1H, d,
Jꢁ3.0 Hz), 6.93 (1H, dd, Jꢁ3.0, 9.0 Hz), 7.60—7.69 (2H, m), 7.81 (1H, d, Jꢁ8.5 Hz), 7.93 (1H, br s), 8.03 (1H, d, Jꢁ8.5 Hz), 8.10
(1H, d, Jꢁ8.5 Hz), 8.45 (1H, br s)
30
32
33
35
1.69—1.87 (2H, m), 2.00—2.15 (2H, m), 2.31 (3H, s), 3.32—3.90 (6H, m), 4.66—4.79 (1H, m), 5.40—5.52 (1H, m), 6.95—7.30
(3H, m), 7.85—7.96 (3H, m), 8.10—8.28 (2H, m), 8.54 (1H, s)
1.68—1.90 (2H, m), 1.95—2.14 (2H, m), 2.33 (3H, s), 3.50—3.93 (4H, m), 4.61—4.71 (1H, m), 6.88 (1H, dd, Jꢁ2.5, 8.0 Hz), 7.05
(1H, s), 7.20 (1H, d, Jꢁ2.0 Hz), 7.40 (1H, d, Jꢁ8.5 Hz), 7.84 (1H, dd, Jꢁ2.0, 8.5 Hz), 8.10—8.27 (3H, m), 8.48 (1H, s), 8.55 (1H, s)
0.90 (3H, t, Jꢁ7.0 Hz), 1.73—1.92 (2H, m), 2.02—2.18 (2H, m), 2.32 (3H, s), 3.26 (2H, q, Jꢁ7.0 Hz), 3.50—3.92 (4H, m), 4.72—
4.83 (1H, m), 6.93 (1H, s), 7.12 (1H, dd, Jꢁ2.5, 8.5 Hz), 7.37 (1H, d, Jꢁ2.5 Hz), 7.84—7.94 (3H, m), 8.10 (1H, d, Jꢁ8.5 Hz),
8.19—8.28 (2H, m), 8.59 (1H, s)
(2H, s), 3.48 (3H, s), 5.21 (2H, s), 6.75 (1H, d, Jꢁ2.5 Hz), 6.83 (1H, dd, dd, Jꢁ3.5, 13.5 Hz), 5.15 (1H, d, Jꢁ7.0 Hz), 5.18 (1H, d, Jꢁ7.0 Hz), 5.23—
Jꢁ2.5, 9.0 Hz), 8.03 (1H, d, Jꢁ9.0 Hz). 5.31 (1H, m), 6.91 (1H, d, Jꢁ2.5 Hz), 7.03 (1H, dd, Jꢁ2.5, 9.0 Hz), 7.57—
7-{1-Hydroxy-2-[5-(methoxymethoxy)-2-nitrophenyl]ethyl}naphtha- 7.64 (1H, m), 7.74—7.80 (1H, m), 7.88—7.96 (3H, m), 8.09 (1H, d,
lene-2-carbonitrile (4) To a solution of 4-(methoxymethoxy)-1-nitro-2- Jꢁ9.0 Hz), 8.19—8.24 (1H, m).
(trimethylsilylmethyl)benzene 2 (27.00 g, 100.2 mmol) and 7-formylnaph-
thalene-2-carbonitrile 3 (19.00 g, 104.9 mmol) in THF (250 ml) was slowly lene-2-carbonitrile (5)
7-{2-[2-Amino-5-(methoxymethoxy)phenyl]-1-hydroxyethyl}naphtha-
solution of 7-{1-hydroxy-2-[5-(methoxy-
A
added a solution of TBAF monohydrate (2.61 g, 9.34 mmol) in THF (15 ml)
and the mixture was stirred at ꢂ10 °C for 30 min. TBAF (75% in H2O,
15 ml, 41.00 mmol) was then added and the mixture was stirred at room tem-
perature for 1 h. NH4Cl solution (250 ml) was added, and the mixture was
methoxy)-2-nitrophenyl]ethyl}naphthalene-2-carbonitrile 4 (24.00 g, 63.43
mmol) in THF (100 ml) and EtOH (100 ml) was hydrogenated over 10%
Pd–C (2.4 g) at room temperature for 4 h with stirring. The catalyst was fil-
tered away, and the filtrate was concentrated. The resulting residue was chro-
extracted with EtOAc. The organic layer was washed with brine, dried and matographed on a silica gel column (hexane/EtOAcꢁ1/2) to give 5 (16.85 g,
concentrated. The resulting residue was chromatographed on a silica gel col-
umn (hexane/EtOAcꢁ1/1) to give 4 (22.07 g, 58.33 mmol, 58%) as a solid.
1H-NMR (CDCl3) d: 3.22 (1H, dd, Jꢁ9.0, 13.5 Hz), 3.41 (3H, s), 3.57 (1H,
48.36 mmol, 76%) as a colorless solid. 1H-NMR (CDCl3) d: 2.96—3.05
(2H, m), 3.38 (3H, s), 5.00 (2H, s), 5.18 (1H, dd, Jꢁ4.5, 7.5 Hz), 6.65 (1H,
d, Jꢁ2.5 Hz), 6.69 (1H, d, Jꢁ8.5 Hz), 6.80 (1H, dd, Jꢁ2.5, 8.5 Hz), 7.58

170
Vol. 54, No. 2
(1H, dd, Jꢁ1.5, 8.5 Hz), 7.65 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.82—7.94 (2H, m),
8.19 (1H, br s).
4.40—4.58 (1H, m), 5.64 (1H, dd, Jꢁ3.0, 10.0 Hz), 6.76—6.88 (2H, m),
7.43 (1H, d, Jꢁ8.5 Hz), 7.55—7.65 (2H, m), 7.80—7.94 (3H, m), 8.19 (1H,
7-{2-[2-(Ethanesulfonyl)amino-5-(methoxymethoxy)phenyl]-1- br s).
hydroxyethyl}naphthalene-2-carbonitrile (6) To a suspension of 7-{2-
[2-amino-5-(methoxymethoxy)phenyl]-1-hydroxyethyl}naphthalene-2-car- 2.12 (3H, s), 2.90—3.11 (2H, m), 3.08 (1H, dd, Jꢁ3.0, 16.5 Hz), 3.28—3.49
9e: 1H-NMR (CDCl3) d: 1.32 (3H, t, Jꢁ7.5 Hz), 1.71—2.08 (4H, m),
bonitrile 5 (3.00 g, 8.61 mmol) in CH2Cl2 (60 ml) were added EtSO2Cl
(1.08 ml, 11.4 mmol) and pyridine (0.96 ml, 11.9 mmol), and the mixture
was stirred overnight at room temperature. The mixture was concentrated
and the resulting residue was diluted with EtOAc and washed with H2O. The
(1H, m), 3.54—3.85 (3H, m), 3.87 (1H, dd, Jꢁ10.5, 16.5 Hz), 4.38—4.55
(1H, m), 5.64 (1H, dd, Jꢁ3.0, 10.5 Hz), 6.70—6.91 (2H, m), 7.43 (1H, d,
Jꢁ8.5 Hz), 7.49—7.63 (2H, m), 7.81—7.93 (3H, m), 8.20 (1H, br s).
9f: 1H-NMR (CDCl3) d: 1.33 (3H, t, Jꢁ7.5 Hz), 1.47 (9H, s), 1.98—2.29
organic layer was dried and concentrated. The resulting residue was dis- (2H, m), 2.92—3.13 (3H, m), 3.42—3.67 (4H, m), 3.86 (1H, dd, Jꢁ10.0,
solved in hexane and EtOAc (2/1), and stirred. The precipitate formed was
16.0 Hz), 4.75—4.90 (1H, m), 5.58—5.68 (1H, m), 6.71—6.85 (2H, m),
7.43 (1H, d, Jꢁ8.5 Hz), 7.50—7.64 (2H, m), 7.79—7.93 (3H, m), 8.21 (1H,
collected by filtration to give 6 (3.20 g, 7.26 mmol, 84%) as a solid. 1H-
NMR (CDCl3) d: 1.44 (3H, t, Jꢁ7.5 Hz), 3.07—3.24 (4H, m), 3.36 (3H, s), br s).
5.02 (1H, d, Jꢁ7.0 Hz), 5.06 (1H, d, Jꢁ7.0 Hz), 5.18—5.28 (1H, m), 6.70
9h: 1H-NMR (CDCl3) d: 1.32 (3H, t, Jꢁ7.5 Hz), 1.28—2.20 (4H, m),
(1H, d, Jꢁ3.0 Hz), 6.91 (1H, dd, Jꢁ3.0, 9.0 Hz), 7.40 (1H, d, Jꢁ9.0 Hz),
7.57—7.69 (2H, m), 7.82 (1H, br s), 7.86—7.96 (2H, m), 8.20 (1H, br s).
2-(7-Cyanonaphthalen-2-yl)-1-(ethanesulfonyl)-5-(methoxymethoxy)-
indoline (7) To a solution of 7-{2-[2-(ethanesulfonyl)amino-5-(methoxy-
1.41 (9H, s), 2.92—4.01 (8H, m), 4.05—4.28 (1H, m), 5.58—5.70 (1H, m),
6.69—6.88 (2H, m), 7.42 (1H, d, Jꢁ8.5 Hz), 7.50—7.68 (2H, m), 7.80—
7.95 (3H, m), 8.21 (1H, br s).
9i: 1H-NMR (CDCl3) d: 1.32 (3H, t, Jꢁ7.5 Hz), 1.42 (9H, s), 1.89—2.09
methoxy)phenyl]-1-hydroxyethyl}naphthalene-2-carbonitrile 6 (3.20 g, 7.26 (2H, m), 2.87 (3H, s), 2.88—3.03 (2H, m), 3.07 (1H, dd, Jꢁ3.0, 16.5 Hz),
mmol) in THF (60 ml) were added n-Bu3P (2.10 ml, 8.43 mmol) and ADDP
(2.20 g, 8.72 mmol), and the mixture was stirred at 0 °C for 1 h. H2O
3.40 (2H, t, Jꢁ7.0 Hz), 3.86 (1H, dd, Jꢁ10.0, 16.5 Hz), 3.94 (2H, t,
Jꢁ6.0 Hz), 5.62 (1H, dd, Jꢁ3.0, 10.0 Hz), 6.73—6.81 (2H, m), 7.42 (1H, d,
(100 ml) was added, and the mixture was extracted with EtOAc. The organic Jꢁ8.5 Hz), 7.57 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.58 (1H, dd, Jꢁ1.5, 8.5 Hz),
layer was washed with brine, dried and concentrated. The resulting residue 7.83—7.93 (3H, m), 8.20 (1H, br s).
was suspended in hexane and EtOAc (1/1), and the mixture was filtered.
The filtrate was concentrated and the resulting residue was chromato-
graphed on a silica gel column (hexane/EtOAcꢁ2/3) to give 7 (3.00 g,
9j: 1H-NMR (CDCl3) d: 1.32 (3H, t, Jꢁ7.5 Hz), 1.45 (9H, s), 1.66—1.78
(4H, m), 2.85 (3H, s), 2.93—3.07 (2H, m), 3.07 (1H, dd, Jꢁ3.0, 16.5 Hz),
3.28 (2H, t, Jꢁ7.0 Hz), 3.86 (1H, dd, Jꢁ10.0, 16.5 Hz), 3.95 (2H, t,
7.10 mmol, 98%) as a colorless solid. 1H-NMR (CDCl3) d: 1.32 (3H, t, Jꢁ6.0 Hz), 5.62 (1H, dd, Jꢁ3.0, 10.0 Hz), 6.77—6.81 (2H, m), 7.42 (1H, d,
Jꢁ7.5 Hz), 2.93—3.13 (3H, m), 3.49 (3H, s), 3.87 (1H, dd, Jꢁ10.0,
16.5 Hz), 5.14 (2H, s), 5.64 (1H, dd, Jꢁ3.0, 10.0 Hz), 6.91—6.98 (2H, m),
7.43 (1H, d, Jꢁ8.5 Hz), 7.54—7.62 (2H, m), 7.81—7.90 (3H, m), 8.21 (1H,
br s).
Jꢁ8.5 Hz), 7.57 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.59 (1H, dd, Jꢁ1.5, 8.5 Hz),
7.84—7.90 (3H, m), 8.20 (1H, br s).
5-[1-(t-Butoxycarbonyl)piperidin-4-ylmethyloxy]-2-(7-cyanonaph-
thalen-2-yl)-1-(ethanesulfonyl)indoline (9g) (Method B) A solution of
2-(7-Cyanonaphthalen-2-yl)-1-(ethanesulfonyl)-5-hydroxyindoline (8) 2-(7-cyanonaphthalen-2-yl)-1-(ethanesulfonyl)-5-hydroxyindoline 8 (1.00 g,
To suspension of 2-(7-cyanonaphthalen-2-yl)-1-(ethanesulfonyl)-5- 2.64 mmol) in DMA (20 ml) was treated with NaH (130 mg, 2.98 mmol, as a
a
(methoxymethoxy)indoline 7 (3.00 g, 7.10 mmol) in EtOAc (80 ml) was
added a 4 N solution of hydrogen chloride in EtOAc (20 ml, 80 mmol) and
the mixture was stirred at room temperature for 6 h. The mixture was con-
centrated and the resulting residue was chromatographed on a silica gel col-
umn (hexane/EtOAcꢁ2/3) to give 8 (2.60 g, 6.87 mmol, 97%) as a colorless
55% w/w dispersion in mineral oil) under cooling conditions and the mix-
ture was stirred at room temperature for 10 min. 1-(t-Butoxycarbonyl)-4-(p-
toluenesulfonyloxymethyl)piperidine (1.20 g, 3.25 mmol) was added and the
whole was stirred overnight at room temperature. The mixture was diluted
with EtOAc and washed with H2O and brine. The organic layer was dried
solid. 1H-NMR (CDCl3) d: 1.32 (3H, t, Jꢁ7.5 Hz), 2.93—3.11 (3H, m), 3.84 and concentrated. The resulting residue was chromatographed on a silica gel
(1H, dd, Jꢁ10.0, 16.5 Hz), 5.62 (1H, dd, Jꢁ3.0, 10.0 Hz), 6.69—6.78 (2H, column (hexane/EtOAcꢁ2/3) to give 9g (1.24 g, 2.15 mmol, 81%) as an
m), 7.36 (1H, d, Jꢁ8.5 Hz), 7.53—7.62 (2H, m), 7.82—7.92 (3H, m), 8.17 amorphous solid. 1H-NMR (CDCl3) d: 1.32 (3H, t, Jꢁ7.5 Hz), 1.46 (9H, s),
(1H, br s).
1.72—2.03 (5H, m), 2.63—2.83 (2H, m), 2.92—3.14 (3H, m), 3.77 (2H, d,
5-[1-(t-Butoxycarbonyl)piperidin-4-yloxy]-2-(7-cyanonaphthalen-2- Jꢁ6.0 Hz), 3.87 (1H, dd, Jꢁ10.0, 16.5 Hz), 4.07—4.23 (2H, m), 5.63 (1H,
yl)-1-(ethanesulfonyl)indoline (9a) (Method A) Diethyl azodicarboxylate dd, Jꢁ3.0, 10.0 Hz), 6.73—6.84 (2H, m), 7.43 (1H, d, Jꢁ8.5 Hz), 7.53—
(DEAD) (0.94 ml, 5.97 mmol) was added to a solution of 2-(7-cyanonaph-
7.63 (2H, m), 7.81—7.92 (3H, m), 8.20 (1H, br s).
thalen-2-yl)-1-(ethanesulfonyl)-5-hydroxyindoline 8 (1.50 g, 3.96 mmol), 1-
t-Butyl 3-(4-Nitrophenoxy)azetidine-1-carboxylate (11a) A solution
(t-butoxycarbonyl)-4-hydroxypiperidine (1.20 g, 5.96 mmol) and PPh3 of t-butyl 3-hydroxyazetidine-1-carboxylate (4.89 g, 28.2 mmol) in DMA
(1.56 g, 5.95 mmol) in THF (60 ml), and the mixture was stirred at room (90 ml) was treated with NaH (1.29 g, 29.6 mmol, as a 55% w/w dispersion
temperature for 4 h. After adding DEAD (0.19 ml, 1.21 mmol), 1-(t-butoxy- in mineral oil) under cooling conditions and the mixture was stirred at room
carbonyl)-4-hydroxypiperidine (0.239 g, 1.19 mmol) and PPh3 (0.312 g, temperature for 15 min. Then a solution of 4-fluoro-1-nitrobenzene 10
1.19 mmol), the mixture was stirred at room temperature for 2 h. H2O was (5.18 g, 36.7 mmol) in DMA (20 ml) was added and the whole was stirred at
added, and the mixture was extracted with EtOAc. The organic layer was room temperature for 4 h. NH4Cl solution was added and the mixture was
washed with brine, dried and concentrated. The resulting residue was chro-
extracted with EtOAc. The organic layer was washed with brine, dried and
concentrated. The resulting residue was chromatographed on a silica gel col-
matographed on a silica gel column (hexane/EtOAcꢁ1/5) to give 9a (1.72 g,
1
3.06 mmol, 77%) as an amorphous solid. H-NMR (CDCl3) d: 1.32 (3H, t, umn (hexane/EtOAcꢁ3/2) to give 11a (7.86 g, 26.7 mmol, 95%) as a yellow
1
Jꢁ7.5 Hz), 1.47 (9H, s), 1.68—1.80 (2H, m), 1.85—1.98 (2H, m), 2.92— solid. H-NMR (CDCl3) d: 1.46 (9H, s), 4.03 (2H, dd, Jꢁ3.5, 9.5 Hz), 4.36
3.13 (2H, m), 3.08 (1H, dd, Jꢁ3.0, 17.0 Hz), 3.26—3.39 (2H, m), 3.63— (2H, dd, Jꢁ6.5, 10.0 Hz), 4.94—5.01 (1H, m), 6.82 (2H, d, Jꢁ9.0 Hz), 8.22
3.77 (2H, m), 3.86 (1H, dd, Jꢁ10.0, 17.0 Hz), 4.34—4.44 (1H, m), 5.63 (2H, d, Jꢁ9.0 Hz).
(1H, dd, Jꢁ3.0, 10.0 Hz), 6.77—6.88 (2H, m), 7.42 (1H, d, Jꢁ8.5 Hz),
7.53—7.64 (2H, m), 7.82—7.92 (3H, m), 8.20 (1H, br s).
t-Butyl
3-[4-Nitro-3-(trimethylsilylmethyl)phenoxy]azetidine-1-car-
boxylate (12a) To a solution of t-butyl 3-(4-nitrophenoxy)azetidine-1-car-
boxylate 11a (10.4 g, 35.3 mmol) in THF (200 ml) was slowly added
(trimethylsilylmethyl)magnesium chloride (1.0 M in Et2O, 37.2 ml,
Similarly, compounds 9b—f, 9h—j were prepared.
9b: 1H-NMR (CDCl3) d: 1.33 (3H, t, Jꢁ7.5 Hz), 1.75—2.15 (4H, m),
2.91—3.14 (3H, m), 3.35—3.52 (2H, m), 3.79—4.02 (3H, m), 4.41—4.54 37.2 mmol) and the mixture was stirred at ꢂ5 °C for 1 h. Then a solution of
(1H, m), 5.55—5.70 (1H, m), 6.56—6.66 (1H, m), 6.69 (1H, d, Jꢁ8.5 Hz), DDQ (10.8 g, 47.6 mmol) in THF (30 ml) was added slowly and the mixture
6.74—6.90 (2H, m), 7.41—7.65 (4H, m), 7.79—7.96 (3H, m), 8.15—8.28 was stirred at 0 °C for 3.5 h. NH4Cl solution was added and the mixture was
(2H, m).
extracted with EtOAc. The organic layer was washed with brine, dried and
concentrated. The resulting residue was chromatographed on a silica gel col-
umn (hexane/EtOAcꢁ13/7) to give 12a (6.25 g, 16.4 mmol, 46%) as a
brown oil. 1H-NMR (CDCl3) d: 0.01 (9H, s), 1.45 (9H, s), 2.63 (2H, s), 4.01
(2H, dd, Jꢁ4.0, 9.5 Hz), 4.32 (2H, dd, Jꢁ7.0, 9.5 Hz), 4.86—4.95 (1H, m),
6.42 (1H, d, Jꢁ2.5 Hz), 6.54 (1H, dd, Jꢁ2.5, 9.0 Hz), 8.04 (1H, d,
9c: 1H-NMR (CDCl3) d: 1.33 (3H, t, Jꢁ7.5 Hz), 1.75—2.04 (4H, m),
2.89—3.10 (2H, m), 3.08 (1H, dd, Jꢁ3.0, 16.5 Hz), 3.25—3.45 (2H, m),
3.56—3.71 (2H, m), 3.87 (1H, dd, Jꢁ10.5, 16.5 Hz), 4.39—4.50 (1H, m),
5.64 (1H, dd, Jꢁ3.0, 10.5 Hz), 6.75—6.90 (2H, m), 7.43 (1H, d, Jꢁ8.5 Hz),
7.52—7.66 (2H, m), 7.80—7.95 (3H, m), 8.20 (1H, br s).
9d: 1H-NMR (CDCl3) d: 1.33 (3H, t, Jꢁ7.5 Hz), 1.45 (9H, s), 1.71—1.98 Jꢁ9.0 Hz).
(4H, m), 2.92—3.22 (3H, m), 3.25—3.42 (1H, m), 3.56—3.70 (1H, m), 3.72
t-Butyl 3-{3-[2-(7-Cyanonaphthalen-2-yl)-2-hydroxyethyl]-4-nitrophe-
noxy}azetidine-1-carboxylate (13a) To a solution of t-butyl 3-[4-nitro-3-
(2H, d, Jꢁ5.5 Hz), 3.87 (1H, dd, Jꢁ10.0, 16.5 Hz), 3.98 (2H, d, Jꢁ3.0 Hz),

February 2006
171
(trimethylsilylmethyl)phenoxy]azetidine-1-carboxylate 12a (6.23 g, 16.4 residue was dissolved in EtOH (20 ml) and H2O (5 ml). The solution was
mmol) and 7-formylnaphthalene-2-carbonitrile 3 (3.26 g, 18.0 mmol) in THF
(120 ml) was slowly added a solution of TBAF monohydrate (0.46 g,
1.65 mmol) in THF (20 ml) and the mixture was stirred at ꢂ10 °C for 1 h.
TBAF (75% in H2O, 3.06 g, 8.78 mmol) in THF (10 ml) was then added and
the mixture was stirred at room temperature for 1 h. NH4Cl solution was
neutralized with NH3 solution and treated with NH4Cl (180 mg, 3.37 mmol).
The mixture was allowed to stand overnight at room temperature and con-
centrated. The resulting residue was chromatographed on a silica gel column
(Cosmosil 75C18-PREPTM, Nacalai Tesque Inc., MeCN/H2O=1/19) to give
the free base of 17g (0.960 g, 1.95 mmol, 91%) as an amorphous solid. This
added, and the mixture was extracted with EtOAc. The organic layer was amorphous solid (250 mg) was dissolved in EtOAc (10 ml) and treated with
washed with brine, dried and concentrated. The crystals that appeared were
filtered off, and the filtrate was concentrated. The resulting residue was chro-
a 4 N solution of hydrogen chloride in EtOAc (0.4 ml, 1.6 mmol). The mix-
ture was concentrated and the resulting residue was lyophilized to give 17
1
matographed on a silica gel column (hexane/EtOAcꢁ1/1) to give 13a (0.287 g, 0.507 mmol) as an amorphous solid. H-NMR (DMSO-d6) d: 1.18
(5.13 g, 10.5 mmol, 64%) as yellow crystals. 1H-NMR (CDCl3) d: 1.46 (9H, (3H, t, Jꢁ7.5 Hz), 1.39—1.62 (2H, m), 1.79—2.11 (3H, m), 2.79—3.45
s), 3.16 (1H, dd, Jꢁ9.0, 13.0 Hz), 3.58 (1H, dd, Jꢁ3.5, 13.0 Hz), 3.92—4.01 (7H, m), 3.81 (2H, d, Jꢁ6.0 Hz), 3.96 (1H, dd, Jꢁ10.0, 17.0 Hz), 5.72—
(2H, m), 4.25—4.35 (2H, m), 4.84—4.91 (1H, m), 5.26 (1H, dd, Jꢁ3.0, 5.83 (1H, m), 6.81—6.97 (2H, m), 7.34 (1H, d, Jꢁ8.5 Hz), 7.60—7.68 (1H,
9.0 Hz), 6.67—6.76 (2H, m), 7.62 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.77 (1H, dd, m), 7.80—7.90 (1H, m), 7.95 (1H, br s), 8.07 (1H, d, Jꢁ8.5 Hz), 8.13 (1H, d,
Jꢁ1.5, 8.5 Hz), 7.90—7.97 (3H, m), 8.10 (1H, d, Jꢁ9,0 Hz), 8.23 (1H, br s).
t-Butyl 3-{4-Amino-3-[2-(7-cyanonaphthalen-2-yl)-2-hydroxyethyl]-
phenoxy}azetidine-1-carboxylate (14a) A solution of t-butyl 3-{3-[2-(7-
Jꢁ8.5 Hz), 8.51 (1H, br s).
Similarly, compounds 17b, 17f—h were prepared.
17f: 1H-NMR (DMSO-d6) d: 1.12—1.31 (3H, m), 1.70—2.48 (2H, m),
cyanonaphthalen-2-yl)-2-hydroxyethyl]-4-nitrophenoxy}azetidine-1-car- 2.82—4.09 (8H, m), 4.72—5.20 (1H, m), 5.66—5.85 (1H, m), 6.77—7.02
boxylate 13a (5.40 g, 11.0 mmol) in THF (60 ml) and EtOH (60 ml) was
hydrogenated over 10% Pd-C (0.81 g) at room temperature for 8 h with
stirring. The catalyst was filtered away, and the filtrate was concentrated. 1.80—2.17 (3H, m), 2.78—3.51 (7H, m), 3.81 (2H, d, Jꢁ6.0 Hz), 3.96 (1H,
(2H, m), 7.25—7.42 (1H, m), 7.50—8.51 (6H, m).
17g: 1H-NMR (DMSO-d6) d: 1.18 (3H, t, Jꢁ7.5 Hz), 1.39—1.64 (2H, m),
The crystals that appeared were filtered off, and the filtrate was concen-
trated. The resulting residue was chromatographed on a silica gel column
(hexane/EtOAcꢁ1/4) to give 14a (1.91 g, 4.16 mmol, 38%) as yellow crys-
tals. 1H-NMR (CDCl3) d: 1.44 (9H, s), 2.92—3.10 (2H, m), 3.83—3.95 (2H,
m), 4.08—4.21 (2H, m), 4.63—4.71 (1H, m), 5.18 (1H, dd, Jꢁ4.0, 8.5 Hz),
dd, Jꢁ10.0, 17.0 Hz), 5.71—5.83 (1H, m), 6.80—6.97 (2H, m), 7.34 (1H, d,
Jꢁ8.5 Hz), 7.58—7.69 (1H, m), 7.81—7.90 (1H, m), 7.95 (1H, br s), 8.07
(1H, d, Jꢁ8.5 Hz), 8.13 (1H, d, Jꢁ8.5 Hz), 8.51 (1H, br s).
17h: H-NMR (DMSO-d6) d: 1.16—1.26 (3H, m), 1.55—1.99 (4H, m),
2.81—3.38 (7H, m), 3.90—4.02 (1H, m), 4.45—4.57 (1H, m), 5.76—5.87
1
6.41 (1H, d, Jꢁ3.0 Hz), 6.49 (1H, dd, Jꢁ3.0, 8.5 Hz), 6.69 (1H, d, (1H, m), 6.90—6.98 (2H, m), 7.26 (1H, d, Jꢁ8.0 Hz), 7.60—7.68 (1H, m),
Jꢁ8.5 Hz), 7.60 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.65 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.86
(1H, br s), 7.89 (1H, d, Jꢁ8.5 Hz), 7.92 (1H, d, Jꢁ8.5 Hz), 8.19 (1H, br s).
t-Butyl 3-{3-[2-(7-Cyanonaphthalen-2-yl)-2-hydroxyethyl]-4-(ethane-
sulfonyl)aminophenoxy}azetidine-1-carboxylate (15a) To a suspension
7.81—7.90 (1H, m), 7.95 (1H, br s), 8.08 (1H, d, Jꢁ8.5 Hz), 8.13 (1H, d,
Jꢁ8.5 Hz), 8.49 (1H, br s).
2-(7-Amidinonaphthalen-2-yl)-1-(ethanesulfonyl)-5-(piperidin-4-
yloxy)indoline Dihydrochloride (17a) (Method D) To a solution of 5-[1-
of t-butyl 3-{4-amino-3-[2-(7-cyanonaphthalen-2-yl)-2-hydroxyethyl]phe- (t-butoxycarbonyl)piperidin-4-yloxy]-2-(7-cyanonaphthalen-2-yl)-1-(ethane-
noxy}azetidine-1-carboxylate 14a (1.86 g, 4.05 mmol) in CH2Cl2 (15 ml) sulfonyl)indoline 9a (208 mg, 0.370 mmol) in MeOH (5 ml) and toluene
and DMA (15 ml) were added EtSO2Cl (0.50 ml, 5.3 mmol) and pyridine (2 ml) were added hydroxylamine hydrochloride (28 mg, 0.40 mmol) and
(0.43 ml, 5.32 mmol), and the mixture was stirred at room temperature for KOt-Bu (42 mg, 0.37 mmol). The mixture was stirred at 70 °C for 3 h. After
7 h. H2O was added and the mixture was extracted with CH2Cl2. The organic adding hydroxylamine hydrochloride (28 mg, 0.40 mmol) and KOt-Bu
layer was washed with brine, dried and concentrated. The resulting residue (42 mg, 0.37 mmol), the mixture was stirred at 70 °C for 5 h. The deposit
was chromatographed on a silica gel column (hexane/EtOAcꢁ7/13) to give was filtered away, and the filtrate was concentrated. The resulting residue
1
15a (1.69 g, 3.06 mmol, 76%) as a brown solid. H-NMR (CDCl3) d: 1.43 was chromatographed on a silica gel column (CH2Cl2/MeOHꢁ23/2) to give
(3H, t, Jꢁ7.5 Hz), 1.43 (9H, s), 3.04—3.24 (4H, m), 3.79—3.95 (2H, m), a colorless solid. This solid was dissolved in AcOH (5 ml) and treated with
4.10—4.26 (2H, m), 4.66—4.76 (1H, m), 5.21 (1H, dd, Jꢁ3.0, 8.5 Hz), 6.46
(1H, d, Jꢁ3.0 Hz), 6.59 (1H, dd, Jꢁ3.0, 9.0 Hz), 7.40 (1H, d, Jꢁ9.0 Hz),
Ac2O (0.050 ml, 0.53 mmol). After stirring at room temperature for 15 min,
the mixture was hydrogenated over 10% Pd-C (50 mg) at room temperature
7.58—7.68 (2H, m), 7.83 (1H, br s), 7.91 (1H, d, Jꢁ8.5 Hz), 7.93 (1H, d, for 6 h with stirring. The catalyst was filtered away, and the filtrate was con-
Jꢁ8.5 Hz), 8.19 (1H, br s).
5-[1-(t-Butoxycarbonyl)azetidin-3-yloxy]-2-(7-cyanonaphthalen-2-yl)-
centrated. The resulting residue was dissolved in MeOH (4 ml) and treated
with a 4 N solution of hydrogen chloride in dioxane (3.0 ml, 12 mmol). The
1-(ethanesulfonyl)indoline (16a) To a solution of t-butyl 3-{3-[2-(7- mixture was stirred at room temperature for 1.5 h. The mixture was concen-
cyanonaphthalen-2-yl)-2-hydroxyethyl]-4-(ethanesulfonyl)aminophe- trated and the resulting residue was purified by preparative HPLC (YMC-
noxy}azetidine-1-carboxylate 15a (1.67 g, 3.03 mmol)in THF (35 ml) were
added n-Bu3P (1.16 ml, 4.66 mmol) and ADDP (1.07 g, 4.24 mmol) in THF
(15 ml), and the mixture was stirred at room temperature for 2 h. H2O was
pack ODS, YMC, H2O/MeCNꢁ17/3) to give the free base of 17a (148 mg,
0.309 mmol) as an amorphous solid. This amorphous solid (6.0 mg) was dis-
solved in a 1 N solution of hydrogen chloride (1 ml) and stored at room tem-
added, and the mixture was extracted with EtOAc. The organic layer was perature for 5 min. The mixture was concentrated to give 17a (6.6 mg,
washed with brine, dried and concentrated. The resulting residue was sus-
pended in hexane and EtOAc (1/1), and the mixture was filtered. The filtrate
was concentrated and the resulting residue was chromatographed on a silica
gel column (hexane/EtOAcꢁ1/1) to give 16a (1.38 g, 2.59 mmol, 85%) as a
0.012 mmol, 83%) as an amorphous solid.
Similarly, compounds 17c—e, 17i and 17j were prepared.
17i: 1H-NMR (DMSO-d6) d: 1.18 (3H, t, Jꢁ7.5 Hz), 2.01—2.08 (2H, m),
2.54 (3H, s), 2.93—3.00 (3H, m), 3.12 (1H, dd, Jꢁ7.0, 14.5 Hz), 3.22—3.31
(1H, m), 3.96 (1H, dd, Jꢁ10.0, 17.0 Hz), 4.02 (2H, t, Jꢁ6.0 Hz), 5.78 (1H,
1
brown amorphous solid. H-NMR (CDCl3) d: 1.32 (3H, t, Jꢁ7.5 Hz), 1.45
(9H, s), 2.92—3.08 (2H, m), 3.09 (1H, dd, Jꢁ3.0, 17.0 Hz), 3.87 (1H, dd, dd, Jꢁ2.5, 10.0 Hz), 6.86 (1H, dd, Jꢁ2.5, 8.5 Hz), 6.92 (1H, d, Jꢁ1.5 Hz),
Jꢁ10.0, 17.0 Hz), 3.99 (2H, dd, Jꢁ4.0, 9.5 Hz), 4.22—4.35 (2H, m), 4.77— 7.35 (1H, d, Jꢁ8.5 Hz), 7.63 (1H, d, Jꢁ9.0 Hz), 7.82 (1H, dd, Jꢁ1.5,
4.90 (1H, m), 5.64 (1H, dd, Jꢁ3.0, 10.0 Hz), 6.57—6.67 (2H, m), 7.42 (1H, 8.5 Hz), 7.95 (1H, br s), 8.07 (1H, d, Jꢁ8.5 Hz), 8.12 (1H, d, Jꢁ8.5 Hz),
d, Jꢁ8.5 Hz), 7.56 (1H, dd, Jꢁ2.0, 8.5 Hz), 7.59 (1H, dd, Jꢁ1.5, 8.5 Hz),
7.82—7.94 (3H, m), 8.20 (1H, br s).
8.49 (1H, br s).
17j: 1H-NMR (DMSO-d6) d: 1.18 (3H, t, Jꢁ7.5 Hz), 1.76 (4H, br s), 2.50
(3H, s), 2.90 (2H, br s), 3.03 (1H, dd, Jꢁ2.5, 10.5 Hz), 3.10—3.21 (1H, m),
Similarly, the benzyloxycarbonyl derivative 16b was prepared.
1
16b: H-NMR (CDCl3) d: 1.47 (9H, s), 1.64—1.80 (2H, m), 1.83—1.98 3.27—3.35 (1H, m), 3.94—4.02 (3H, m), 5.78 (1H, dd, Jꢁ2.5, 10.5 Hz),
(2H, m), 3.00 (1H, dd, Jꢁ2.5, 17.0 Hz), 3.25—3.38 (2H, m), 3.63—3.83 6.86 (1H, dd, Jꢁ2.0, 9.0 Hz), 6.92 (1H, s), 7.35 (1H, d, Jꢁ8.5 Hz), 7.64 (1H,
(3H, m), 4.33—4.44 (1H, m), 4.89—5.25 (2H, m), 5.56—5.70 (1H, m), d, Jꢁ8.5 Hz), 7.86 (1H, d, Jꢁ8.5 Hz), 7.95 (1H, br s), 8.07 (1H, d,
6.73—7.25 (7H, m), 7.39—7.64 (3H, m), 7.76— 7.92 (3H, m), 8.04 (1H, Jꢁ8.5 Hz), 8.12 (1H, d, Jꢁ8.5 Hz), 8.52 (1H, br s).
br s).
2-(7-Amidinonaphthalen-2-yl)-1-(ethanesulfonyl)-5-(piperidin-4-yl-
5-[1-(Acetimidoyl)piperidin-4-yloxy]-2-(7-amidinonaphthalen-2-yl)-1-
(ethanesulfonyl)indoline Dihydrochloride (18a) To a solution of 2-(7-
methyloxy)indoline Dihydrochloride (17g) (Method C) HCl gas was amidinonaphthalen-2-yl)-1-(ethanesulfonyl)-5-(piperidin-4-yloxy)indoline
bubbled through solution of 5-[1-(t-butoxycarbonyl)piperidin-4-yl- dihydrochloride 17a (142 mg, 0.297 mmol) in EtOH (6 ml) were added ethyl
a
methoxy]-2-(7-cyanonaphthalen-2-yl)-1-(ethanesulfonyl)indoline 9g (1.24 g,
2.15 mmol) in CH2Cl2 (10 ml) and EtOH (10 ml) at 0 °C. Then the mixture
was stirred at room temperature for 3 h and concentrated. The resulting
acetimidate hydrochloride (81 mg, 0.66 mmol) and Et3N (0.14 ml, 1.0
mmol). The mixture was stirred overnight at room temperature. The mixture
was concentrated and the resulting residue was purified by preparative

172
Vol. 54, No. 2
(5.87 g, 30.1 mmol) in THF (250 ml) was added lithium diisopropylamide
(LDA) (2.0 M in n-heptane/THF/ethylbenzene, 22.6 ml, 45.2 mmol) at
ꢂ65 °C and the mixture was stirred at ꢂ65 °C for 15 min. 2-Formyl-4-
(methoxymethoxy)-1-nitrobenzene 23 (9.52 g, 45.1 mmol) in THF (50 ml)
was added and the mixture was stirred at ꢂ65 °C for 3 h. NH4Cl solution
was added, and the mixture was extracted with EtOAc. The organic layer
was washed with brine, dried and concentrated. The resulting residue was
chromatographed on a silica gel column (hexane/EtOAcꢁ3/2—1/1) to give
7-{3-hydroxy-3-[5-(methoxymethoxy)-2-nitrophenyl]propionyl}naphtha-
lene-2-carbonitrile (7.26 g, 17.9 mmol, 59%) as a colorless solid. This solid
(7.25 g, 17.8 mmol) was dissolved in ClCH2CH2Cl (200 ml) and treated with
p-toluenesulfonic acid (TsOH) monohydrate (0.68 g, 3.57 mmol) at 40 °C.
The solution was refluxed for 2 h, then cooled to give colorless crystals. The
crystals were filtered off and then dissolved in DMA (200 ml). The solution
was treated with MOMCl (1.68 ml, 22.1 mmol) and Et3N (3.10 ml,
22.4 mmol) at 0 °C, and stirred for 4 h. H2O was added, and the mixture was
extracted with EtOAc. The organic layer was washed with brine, dried and
concentrated. The resulting residue was chromatographed on a silica gel col-
umn (CH2Cl2/EtOAcꢁ7/3) to give 25 (5.32 g, 13.7 mmol, 92%, 2 steps) as a
HPLC (YMC-pack ODS, YMC, H2O/MeCNꢁ4/1) to give the free base of
18a (135 mg, 0.234 mmol) as an amorphous solid. This amorphous solid
(135 mg) was dissolved in MeOH (4 ml) and treated with a 4 N solution of
hydrogen chloride in dioxane (0.19 ml, 0.76 mmol). The mixture was al-
lowed to stand at room temperature for 5 min and then concentrated. The re-
sulting residue was lyophilized to give 18a (134 mg, 0.226 mmol, 76%) as
an amorphous solid.
Similarly, compounds 18f—j were prepared.
5-[1-(Acetimidoyl)azetidin-3-yloxy]-2-(7-cyanonaphthalen-2-yl)-1-
(ethanesulfonyl)indoline (20) To a solution of 5-[1-(t-butoxycarbonyl)-
azetidin-3-yloxy]-2-(7-cyanonaphthalen-2-yl)-1-(ethanesulfonyl)indoline
16a (390 mg, 0.731 mmol) in dioxane (4 ml) was added a 4 N solution of hy-
drogen chloride in dioxane (4 ml) and the mixture was stirred at room tem-
perature for 3.5 h. The mixture was concentrated and the resulting residue
(19) was dissolved in EtOH (5 ml) and CH2Cl2 (5 ml). After adding ethyl
acetimidate hydrochloride (198 mg, 1.60 mmol) and Et3N (0.34 ml,
2.45 mmol), the mixture was stirred overnight at room temperature. After
adding ethyl acetimidate hydrochloride (99 mg, 0.80 mmol) and Et3N
(0.17 ml, 1.2 mmol), the mixture was stirred at room temperature for 4 h.
The mixture was concentrated and the resulting residue was purified by
preparative HPLC (YMC-pack ODS, YMC, H2O/MeCNꢁ1/1) to give 20
1
yellow solid. H-NMR (CDCl3) d: 3.54 (3H, s), 5.32 (2H, s), 7.20 (1H, dd,
Jꢁ2.5, 9.0 Hz), 7.26—7.33 (2H, m), 7.76 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.99—
8.05 (2H, m), 8.18 (1H, d, Jꢁ9.0 Hz), 8.21—8.28 (2H, m), 8.41 (1H, br s),
8.61 (1H, br s).
1
(294 mg, 0.619 mmol, 85%) as a pale yellow solid. H-NMR (DMSO-d6) d:
1.18 (3H, t, Jꢁ7.5 Hz), 2.08 and 2.09 (together 3H, each singlet), 3.01 (1H,
dd, Jꢁ3.0, 17.0 Hz), 3.06—3.17 (1H, m), 3.23—3.38 (1H, m), 3.96 (1H, dd,
Jꢁ10.0, 17.0 Hz), 4.04—4.15 (1H, m), 4.28—4.38 (1H, m), 4.55—4.65
(1H, m), 4.68—4.79 (1H, m), 5.05—5.13 (1H, m), 5.77 (1H, dd, Jꢁ3.0,
10.0 Hz), 6.81 (1H, dd, Jꢁ2.5, 9.0 Hz), 6.87 (1H, br s), 7.37 (1H, d,
Jꢁ9.0 Hz), 7.62 (1H, d, Jꢁ8.5 Hz), 7.78 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.95 (1H,
br s), 8.06 (1H, d, Jꢁ8.5 Hz), 8.09 (1H, d, Jꢁ8.5 Hz), 8.60 (1H, br s).
5-[1-(Acetimidoyl)azetidin-3-yloxy]-2-(7-amidinonaphthalen-2-yl)-1-
(ethanesulfonyl)indoline Dihydrochloride (21) (Method C) HCl gas was
bubbled through a solution of 5-[1-(acetimidoyl)azetidin-3-yloxy]-2-(7-
cyanonaphthalen-2-yl)-1-(ethanesulfonyl)indoline 20 (280 mg, 0.590 mmol)
in CH2Cl2 (8 ml) and EtOH (5 ml) at 0 °C. Then the mixture was stirred at
room temperature for 8.5 h and concentrated. The resulting residue was dis-
solved in EtOH (9 ml) and treated with NH4Cl (57.0 mg, 1.07 mmol) in H2O
(3 ml) and NH3 solution (0.120 ml, 1.97 mmol). The mixture was stirred
overnight at room temperature and allowed to stand overnight at 0 °C. The
mixture was concentrated and the resulting residue was purified by prepara-
tive HPLC (YMC-pack ODS, YMC, H2O/MeCNꢁ4/1) to give the free base
of 21 (94 mg) as an amorphous solid. This amorphous solid (94 mg) was dis-
solved in MeOH (5 ml) and treated with a 4 N solution of hydrogen chloride
in dioxane (0.14 ml, 0.56 mmol) at 0 °C. The mixture was concentrated and
the resulting residue was lyophilized to give 21 (90 mg, 0.16 mmol, 27%) as
an amorphous solid.
7-{1-Hydroxy-3-[5-(methoxymethoxy)-2-nitrophenyl]-2-propene-1-
yl}naphthalene-2-carbonitrile (26) To a solution of 7-{3-[5-(methoxy-
methoxy)-2-nitrophenyl]acryloyl}naphthalene-2-carbonitrile 25 (4.35 g,
11.2 mmol) in EtOH (65 ml) and CH2Cl2 (65 ml) was added NaBH4 (0.42 g,
11.1 mmol) and the mixture was stirred at room temperature for 3 h. H2O
was added, and the mixture was concentrated. The resulting residue was
extracted with EtOAc and the organic layer was washed with brine, dried
and concentrated. The resulting residue was chromatographed on a silica
gel column (hexane/EtOAcꢁ1/1) to give 26 (2.81 g, 7.20 mmol, 64%) as a
yellow oil. 1H-NMR (CDCl3) d: 3.46 (3H, s), 5.22 (2H, s), 5.61—5.67 (1H,
m), 6.31 (1H, dd, Jꢁ6.5, 15.5 Hz), 7.02 (1H, dd, Jꢁ2.5, 9.0 Hz), 7.12 (1H, d,
Jꢁ2.5 Hz), 7.35 (1H, d, Jꢁ15.5 Hz), 7.61 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.74 (1H,
dd, Jꢁ1.5, 8.5 Hz), 7.92 (2H, d, Jꢁ8.5 Hz), 7.99 (1H, br s), 8.04 (1H, d,
Jꢁ9.0 Hz), 8.24 (1H, br s).
7-{3-[2-Amino-5-(methoxymethoxy)phenyl]-1-hydroxypropyl}naph-
thalene-2-carbonitrile (27)
A
solution of 7-{1-hydroxy-3-[5-(me-
thoxymethoxy)-2-nitrophenyl]-2-propene-1-yl}naphthalene-2-carbonitrile
26 (3.68 g, 9.43 mmol) in THF (30 ml) and EtOH (30 ml) was hydrogenated
over 10% Pd–C (0.74 g) at room temperature for 5 h with stirring. The
catalyst was filtered away, and the filtrate was concentrated. The resulting
residue was chromatographed on a silica gel column (hexane/EtOAcꢁ1/4)
1
to give 27 (2.87 g, 7.92 mmol, 84%) as a yellow amorphous solid. H-NMR
(CDCl3) d: 2.02—2.16 (2H, m), 2.61—2.81 (2H, m), 3.48 (3H, s),
4.79 (1H, dd, Jꢁ4.0, 9.0 Hz), 5.09 (2H, s), 6.67 (1H, d, Jꢁ8.5 Hz),
6.75—6.85 (2H, m), 7.58 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.62 (1H, dd, Jꢁ2.0,
8.5 Hz), 7.81—7.92 (3H, m), 8.18 (1H, br s).
2-Formyl-4-(methoxymethoxy)-1-nitrobenzene (23) To a solution of
2-formyl-4-hydroxy-1-nitrobenzene 22 (15.91 g, 95.20 mmol) in PhCH3
(50 ml) and CH2Cl2 (100 ml) and DMA (50 ml) were added MOMCl
(7.88 ml, 104 mmol) and Et3N (14.59 ml, 104.7 mmol) at 0 °C. The mixture
was stirred overnight at room temperature. H2O was added, and the mixture
was extracted with EtOAc. The organic layer was washed with brine, dried
and concentrated. The resulting residue was chromatographed on a silica gel
column (hexane/EtOAcꢁ3/1) to give 23 (14.66 g, 69.42 mmol, 73%) as a
7-{3-[2-(Ethanesulfonyl)amino-5-(methoxymethoxy)phenyl]-1-hydrox-
ypropyl}naphthalene-2-carbonitrile (28) To a solution of 7-{3-[2-amino-
5-(methoxymethoxy)phenyl]-1-hydroxypropyl}naphthalene-2-carbonitrile
27 (2.09 g, 5.77 mmol) in CH2Cl2 (60 ml) were added EtSO2Cl (0.71 ml,
7.49 mmol) and pyridine (0.61 ml, 7.54 mmol), and the mixture was stirred
at room temperature for 8 h. H2O was added, and the mixture was extracted
with CH2Cl2. The organic layer was washed with brine, dried and concen-
trated. The resulting residue was chromatographed on a silica gel column
(hexane/EtOAcꢁ2/3) to give 28 (2.41 g, 5.30 mmol, 92%) as a colorless
1
pale green solid. H-NMR (CDCl3) d: 3.50 (3H, s), 5.30 (2H, s), 7.31 (1H,
dd, Jꢁ3.0, 9.0 Hz), 7.49 (1H, d, Jꢁ3.0 Hz), 8.16 (1H, d, Jꢁ9.0 Hz), 10.47
(1H, s).
7-Acetylnaphthalene-2-carbonitrile (24) To a solution of 7-formyl-
naphthalene-2-carbonitrile 3 (3.00 g, 16.6 mmol) in THF (80 ml) was added
CH3MgBr (1.0 M in THF, 17.4 ml, 17.4 mmol) at ꢂ70 °C and the mixture
was stirred at ꢂ70 °C for 2 h. NH4Cl solution was added, and the mixture
was extracted with EtOAc. The organic layer was washed with brine, dried
and concentrated. The resulting residue was chromatographed on a silica gel
column (hexane/EtOAcꢁ3/2) to give 7-(1-hydroxyethyl)naphthalene-2-car-
bonitrile (1.64 g, 8.31 mmol, 50%) as a pale yellow oil. This oil (236 mg,
1.20 mmol) was dissolved in CH2Cl2 (10 ml) and treated with MnO2 (1.04 g,
12.0 mmol). The mixture was stirred overnight at room temperature. The
mixture was filtered, and the filtrate was concentrated. The resulting residue
was chromatographed on a silica gel column (hexane/EtOAcꢁ7/3) to give
24 (177 mg, 0.906 mmol, 76%) as a colorless solid. 1H-NMR (CDCl3) d:
2.76 (3H, s), 7.74 (1H, dd, Jꢁ1.5, 9.0 Hz), 7.96—8.00 (2H, m), 8.20 (1H,
dd, Jꢁ1.5, 9.0 Hz), 8.37 (1H, br s), 8.51 (1H, br s).
1
amorphous solid. H-NMR (CDCl3) d: 1.39 (3H, t, Jꢁ7.5 Hz), 2.01—2.18
(2H, m), 2.78—2.90 (1H, m), 2.94—3.06 (1H, m), 3.12 (2H, q, Jꢁ7.5 Hz),
3.48 (3H, s), 4.74—4.81 (1H, m), 5.15 (2H, s), 6.87—6.96 (2H, m), 7.35—
7.43 (1H, m), 7.54—7.63 (2H, m), 7.81 (1H, br s), 7.85 (1H, d, Jꢁ8.5 Hz),
7.88 (1H, d, Jꢁ8.5 Hz), 8.15 (1H, br s).
2-(7-Cyanonaphthalen-2-yl)-1-(ethanesulfonyl)-6-(methoxymethoxy)-
1,2,3,4-tetrahydroquinoline (29) To a solution of 7-{3-[2-(ethanesul-
fonyl)amino-5-(methoxymethoxy)phenyl]-1-hydroxypropyl}naphthalene-2-
carbonitrile 28 (2.38 g, 5.24 mmol) in THF (50 ml) were added n-Bu3P
(1.87 ml, 7.51 mmol) and ADDP (1.72 g, 6.82 mmol) in THF (20 ml) at 0 °C,
and the mixture was stirred at room temperature for 7 h. NH4Cl solution was
added, and the mixture was extracted with EtOAc. The organic layer was
washed with brine, dried and concentrated. The resulting residue was chro-
matographed on a silica gel column (hexane/EtOAcꢁ3/2—1/1) to give 29
(2.15 g, 4.93 mmol, 94%) as a colorless amorphous solid. 1H-NMR (CDCl3)
7-{3-[5-(Methoxymethoxy)-2-nitrophenyl]acryloyl}naphthalene-2-car-
bonitrile (25) To a solution of 7-acetylnaphthalene-2-carbonitrile 24

February 2006
173
hydrogen atoms and isotropic temperature factors for the hydrogen atoms.
Crystal data: C31H35N3O5S; Mꢁ561.69; monoclinic, space group P21,
d: 1.33 (3H, t, Jꢁ7.5 Hz), 2.05—2.18 (1H, m), 2.52—2.80 (3H, m), 2.95—
3.19 (2H, m), 3.48 (3H, s), 5.15 (2H, s), 5.63 (1H, t, Jꢁ7.0 Hz), 6.81 (1H, d,
Jꢁ3.0 Hz), 6.96 (1H, dd, Jꢁ3.0, 9.0 Hz), 7.53—7.59 (2H, m), 7.75 (1H, d,
Jꢁ9.0 Hz), 7.78 (1H, br s), 7.83 (1H, d, Jꢁ8.5 Hz), 7.86 (1H, d, Jꢁ8.5 Hz),
8.16 (1H, br s).
aꢁ5.778(4) Å,
bꢁ8.012(4) Å,
cꢁ31.454(4) Å,
bꢁ91.43(4)°;
Vꢁ1455.8(10) Å3, Zꢁ2, DCꢁ1.281 g/cm3, Rꢁ0.056, RWꢁ0.091 for 2862 re-
flections with Iꢄ3s.
X-Ray Crystallographic Analysis of FXa Complexed with (R)-18a
Human FXa was purchased from Enzyme Research Laboratories, Inc., IN,
U.S.A. and purified as described.20) Briefly, FXa was treated with a-chy-
motrypsin to remove the first 44 amino acids of the light chain (Gla do-
main), resulting in des-Gla-FXa. Then des-Gla-FXa was purified on an
anion-exchange column and concentrated to 15 mg/ml. Crystals were ob-
tained at 295 K using the hanging-drop vapour-diffusion technique, equili-
brated against a reservoir solution of 20% PEG3350, 0.5 M sodium acetate,
8 mM calcium chloride and 0.1 M imidazole-malic acid (pH 5.5) by the mi-
croseeding technique. X-ray diffraction data were collected in a glass capil-
lary with the wavelength set to 1.0 Å at the BL-6B station (Photon Factory,
Tsukuba, Japan). The crystal belongs to the P212121 space group, with
aꢁ57.0 Å, bꢁ73.1 Å and cꢁ79.8 Å. The diffraction data were integrated
and scaled with the programs Denzo and Scalepack (HKL Research, Inc.),21)
with an Rsym(I) of 4.8% and a completeness of 96.3% to the highest resolu-
tion of 2.3 Å. The FXa structure from the complex structure of FXa and DX-
9065a (PDB code: 1FAX)14) was used as a starting model for refinement.
The electron density of (R)-18a was clearly defined in the initial electron
density map. The model of FXa with (R)-18a was rebuilt with the program
O22) and refined with X-PLOR and CNX23). Residues 45—87 of the light
chain were not built due to weak electron densities. The final structure gave
6-[1-(Acetimidoyl)piperidin-4-yloxy]-2-(7-amidinonaphthalen-2-yl)-1-
(ethanesulfonyl)-1,2,3,4-tetrahydroquinoline Dihydrochloride (30) 2-
(7-Cyanonaphthalen-2-yl)-1-(ethanesulfonyl)-6-(methoxymethoxy)-1,2,3,4-
tetrahydroquinoline 29 was converted to 30 by the same procedure as that
for 18a. Compound 30 was obtained (44%, 5 steps) as an amorphous solid.
5-[1-(t-Butoxycarbonyl)piperidin-4-yloxy]-2-(7-cyanonaphthalen-2-
yl)indoline (31) A solution of benzyl 5-[1-(t-butoxycarbonyl)piperidin-
4-yloxy]-2-(7-cyanonaphthalen-2-yl)indoline-1-carboxylate 16b (6.00 g,
9.94 mmol) in THF (30 ml) and EtOH (30 ml) was hydrogenated over 10%
Pd–C (1.20 g) at room temperature for 4 h with stirring. The catalyst was fil-
tered away, and the filtrate was concentrated. The resulting residue was chro-
matographed on a silica gel column (CH2Cl2/EtOAcꢁ20/1—0/1) to give 31
(4.16 g, 8.86 mmol, 89%) as pale yellow crystals. 1H-NMR (CDCl3) d: 1.47
(9H, s), 1.63—1.99 (4H, m), 3.01 (1H, dd, Jꢁ10.0, 15.0 Hz), 3.21—3.34
(2H, m), 3.50 (1H, dd, Jꢁ9.0, 15.0 Hz), 3.65—3.80 (2H, m), 4.22—4.33
(1H, m), 5.15 (1H, dd, Jꢁ9.0, 10.0 Hz), 6.61—6.78 (3H, m), 7.60 (1H, dd,
Jꢁ2.0, 8.5 Hz), 7.74 (1H, dd, Jꢁ2.0, 8.5 Hz), 7.86—7.94 (3H, m), 8.20 (1H,
br s).
5-[1-(Acetimidoyl)piperidin-4-yloxy]-2-(7-amidinonaphthalen-2-yl)in-
doline Dihydrochloride (32) and 5-[1-(Acetimidoyl)piperidin-4-yloxy]-2-
(7-amidinonaphthalen-2-yl)indole Trihydrochloride (33) 5-[1-(t-Bu-
toxycarbonyl)piperidin-4-yloxy]-2-(7-cyanonaphthalen-2-yl)indoline 31 was
converted to 32 and 33 by the same procedure as that for 18a. Compound 32
was obtained (30%, 3 steps) as a yellow amorphous solid and compound 33
was obtained (0.7%, 3 steps) as a yellow amorphous solid.
Rcrystꢁ22.3% and Rfreeꢁ26.2% at 2.3 Å resolution with good stereochem-
istry, root mean square (RMS) deviation from ideal bond length of 0.004 Å
and RMS deviation from ideal bond angles of 1.1°. The geometry of the
model was checked with the program PROCHECK24); there were no
residues in the disallowed regions of the Ramachandran plot. The figures
were produced with InsightII (Molecular Simulations Inc.).
5-[1-(t-Butoxycarbonyl)piperidin-4-yloxy]-2-(7-cyanonaphthalen-2-
yl)-1-(ethanesulfonyl)indole (34) To
a solution of 5-[1-(t-butoxycar-
Biology. Anti-FXa Assay The hydrolysis of the chromogenic sub-
strates was assayed by continuously measuring absorbance at 405 nm at
37 °C with a microplate reader (SPECTRA max PLUS 384, Molecular De-
vices, CA, U.S.A.). Reaction mixtures (90 ml) were prepared in 96-well
plates containing human FXa (0.5 IU, Enzyme Research Laboratories, Inc.,
IN, U.S.A.) and compounds in reaction buffer (50 mM Tris–HCl–150 mM
NaCl, pH 8.4). Reactions were initiated by the addition of 10 ml of S-2222
(4 mM, Daiichi Pure Chemical, Japan) and monitored for 5 min. The concen-
tration required to inhibit enzyme activity by 50% (IC50) was estimated from
dose-response curves.
Coagulation Assay Citrated blood samples were collected from healthy
male volunteers and male hamsters (Japan SLC). Platelet-poor plasma was
prepared by centrifugation at 2000ꢅg for 10 min and stored at ꢂ20 °C until
use. Plasma clotting times were determined using a COAGMASTER II
(Sankyo, Japan). Prothrombin time (PT) was measured using SIMPLASTIN
EXCEL (Organon Teknika, NC, U.S.A.). Coagulation times for each com-
pound were compared with coagulation times measured using distilled water
as a control. Each measurement was performed three times. The concentra-
tion required to double the clotting time (CT2) was estimated by linear re-
gression analysis using two data points, the two mean values of the concen-
trations closest to the predicted 2-fold PT on either side.
bonyl)piperidin-4-yloxy]-2-(7-cyanonaphthalen-2-yl)indoline 31 (500 mg,
1.06 mmol) in CH2Cl2 (10 ml) was added MnO2 (926 mg, 10.7 mmol) and
the mixture was refluxed for 9 h. Then the mixture was stirred overnight at
room temperature, and the mixture was filtered. The filtrate was concen-
trated to give 5-[1-(t-butoxycarbonyl)piperidin-4-yloxy]-2-(7-cyanonaph-
thalen-2-yl)indole (438 mg, 0.936 mmol, 88%) as a yellow solid. This solid
(338 mg) was dissolved in DMF (6 ml) and treated with NaH (58 mg,
1.33 mmol, as a 55% w/w dispersion in mineral oil) under cooling condi-
tions. The mixture was stirred at room temperature for 0.5 h. EtSO2Cl
(0.140 ml, 1.48 mmol) and 4-dimethylaminopyridine (4.4 mg, 0.036 mmol)
were added and the whole was stirred overnight at room temperature. H2O
was added and the mixture was extracted with EtOAc. The organic layer was
washed with brine, dried and concentrated. The resulting residue was chro-
matographed on a silica gel column (hexane/EtOAcꢁ4/1—1/4) to give 34
(326 mg, 0.583 mmol, 81%) as a brown amorphous solid. 1H-NMR (CDCl3)
d: 1.01 (3H, t, Jꢁ7.0 Hz), 1.48 (9H, s), 1.74—1.87 (2H, m), 1.91—2.03
(2H, m), 2.97 (2H, q, Jꢁ7.0 Hz), 3.27—3.43 (2H, m), 3.67—3.82 (2H, m),
4.47—4.57 (1H, m), 6.73 (1H, s), 6.87—7.14 (3H, m), 7.66 (1H, d,
Jꢁ8.5 Hz), 7.85—8.09 (4H, m), 8.28 (1H, s).
2-(7-Amidinonaphthalen-2-yl)-1-(ethanesulfonyl)-5-(piperidin-4-
yloxy)indole Dihydrochloride (35) 5-[1-(t-Butoxycarbonyl)piperidin-4-
yloxy]-2-(7-cyanonaphthalen-2-yl)-1-(ethanesulfonyl)indole 34 was con-
verted to 35 by the same procedure as that for 18a. Compound 35 was ob-
tained (32%, 3 steps) as a pale purple amorphous solid.
(R)-7-{2-[2-Amino-5-(methoxymethoxy)phenyl]-1-hydroxyethyl}naph-
thalene-2-carbonitrile ((R)-5) and (S)-7-{2-[2-Amino-5-(methoxyme-
thoxy)phenyl]-1-hydroxyethyl}naphthalene-2-carbonitrile ((S)-5) 7-{2-
[2-Amino-5-(methoxymethoxy)phenyl]-1-hydroxyethyl}naphthalene-2-car-
bonitrile 5 (2.20 g, 6.31 mmol) was separated into less polar (R)-5 and more
polar (S)-5 by preparative HPLC (CHIRALCEL OD, Daicel Chemical In-
dustries, Ltd., hexane/i-PrOHꢁ2/3). (R)-5 was obtained (1.16 g, quant.,
99%ee) as a solid and (S)-5 was obtained (1.14 g, quant., 99%ee) as a solid.
Optically active bisamidine derivatives ((R)-18a and (S)-18a) were simi-
larly prepared as racemates from (S)-5 and (R)-5, respectively.
Acknowledgments We wish to thank Mr. Yoji Furukawa for the X-ray
crystallographic analysis, Professor Noriyoshi Sakabe and the staff of Pho-
ton Factory for their help at the BL-6B station during X-ray data collec-
tion,25) Ms. Naoko Suzuki and Ms. Yumiko Fujisawa for their expert techni-
cal assistance, and Dr. Ken-ichi Otsuguro for his helpful discussions.
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