Indoline derivatives II: Synthesis and factor Xa (FXa) inhibitory activities

Article abstract of DOI:10.1248/cpb.55.393

Factor Xa (FXa) is well known to play a pivotal role in blood coagulation, so FXa inhibitor is a promising drug candidate for prophylaxis and treatment of thromboembolic diseases. In the course of our research, we have found that (R)-5-[1-(acetimidoyl)pip

Full text of DOI:10.1248/cpb.55.393

March 2007
Chem. Pharm. Bull. 55(3) 393—402 (2007)
393
Indoline Derivatives II: Synthesis and Factor Xa (FXa) Inhibitory
Activities
a
Tetsuji NOGUCHI, Naoki TANAKA, ,a Toyoki NISHIMATA,a Riki GOTO,a Miho HAYAKAWA,a
*
Atsuhiro SUGIDACHI,b Taketoshi OGAWA,b Fumitoshi ASAI,b Tomoko OZEKI,c and Koichi FUJIMOTO
a,1)
a Medicinal Chemistry Research Laboratories, Sankyo Co., Ltd.; b Pharmacology and Molecular Biology Research
Laboratories, Sankyo Co., Ltd.; and c Drug Metabolism and Pharmacokinetics Research Laboratories, Sankyo Co., Ltd.;
1–2–58 Hiromachi, Shinagawa-ku, Tokyo 140–8710, Japan.
Received September 28, 2006; accepted December 16, 2006; published online December 19, 2006
Factor Xa (FXa) is well known to play a pivotal role in blood coagulation, so FXa inhibitor is a promising
drug candidate for prophylaxis and treatment of thromboembolic diseases. In the course of our research, we
have found that (R)-5-[1-(acetimidoyl)piperidin-4-yloxy]-2-(7-amidinonaphthalen-2-yl)-1-(ethanesulfonyl)indo-
line ((R)-1) showed potent FXa inhibitory activity in vitro. However, single oral administation (RS)-1 showed high
toxicity in mice. Among newly synthesized compounds, ({(RS)-5-[1-(acetimidoyl)piperidin-4-yloxy]-2-(7-amidi-
nonaphthalen-2-yl)indolin-1-yl}sulfonyl)acetic acid ((RS)-11d) showed more potent FXa inhibitory activity and
higher safety than (RS)-1. The R-isoform of compound 11d ((R)-11d) exhibited potent in vitro anticoagulant ac-
tivity in human and hamster plasma. Orally administered (R)-11d also showed dose-dependent potent anticoagu-
lant activity in hamsters, marmosets and cynomolgus monkeys. Compound (R)-11d with potent anticoagulant
activity and high safety is therefore favorable as a novel oral FXa inhibitor.
Key words factor Xa (FXa) inhibitory activity; indoline derivative; anticoagulant
Intravascular clot formation is a serious event which leads toxicity by further structural optimization of (RS)-1. In this
to a number of ischemic diseases, such as myocardial infarc- study, we examined substituents on the indoline ring in order
tion, stroke and venous thromboembolism. At present, war- to identify more desirable compounds. Herein, we describe
farin is the sole oral anticoagulant that is being widely used the synthesis and structure-activity relationships (SARs) of
for prophylaxis and treatment of thrombosis. However, many these compounds.
reports have mentioned the limitations of warfarin.2—4) In-
deed, warfarin requires frequent international normalized Chemistry
ratio (INR) monitoring because of its narrow therapeutic
Key intermediates 8a—g and i were synthesized as shown
window and the large inter- and intraindividual variability in in Chart 1. After reduction of the nitro group of alcohol 2 by
its effect. In addition, its onset of anticoagulant action is con- catalytic hydrogenation,8) aniline 3 was reacted with acyl
siderably slow and it interacts with many foods and conven- reagents or sulfonyl reagents to give anilides 4a—g. An in-
tional agents. Accordingly, novel oral anticoagulants with tramolecular Mitsunobu reaction9) of 4a—g with n-Bu3P
high efficacy and without INR monitoring are desired.
and 1,1ꢀ-(azodicarbonyl)dipiperidine (ADDP) afforded cor-
Factor Xa (FXa) has been thought of as a particularly responding indolines 5a—g. After removing the methoxy-
promising target for effective anticoagulation because it acts methyl (MOM) group of 5a—g by treatment with HCl,
at the convergence point of the intrinsic and extrinsic coagu- phenols 6a—g was converted to intermediates 8a—g
lation pathways. Moreover, one molecule of FXa generates by means of a Mitsunobu reaction10) with alcohol 7. Further-
more than 100 thrombin molecules.5) It is thought that inhibi- more, after removing the benzyloxycarbonyl (Z) group of
tion of FXa effectively blocks thrombin formation, thereby compound 8h8) by catalytic hydrogenation, the resulting in-
diminishing thrombin-mediated fibrin clot formation. Recent doline derivative was acylated with ethyl malonyl chloride to
research has focused on the identification of orally available give ethyl malonate intermediate 8i.
small-molecule FXa inhibitors that do not require routine co-
The syntheses of the amidine derivatives from intermedi-
ates 8a—g, i are outlined in Chart 2. Compounds 8a—g, i
agulation monitoring.6,7)
In a previous paper, we reported that compound (R)-1 (Fig. were converted to the corresponding amidines 9a—g, i by
1), which has the (R)-configuration at the 2-position of the bubbling HCl gas into a mixture of ethanol and di-
indoline ring, showed potent inhibitory activity against FXa chloromethane, followed by amination of the resulting imi-
in vitro.8) However, orally administered (RS)-1 had high toxi- dates (Method A), or by treatment with hydroxylamine, fol-
city in mice. We intended to explore new indoline com- lowed by acylation and hydrogenation of the resulting ami-
pounds with potent FXa inhibitory activity and diminished doximes (Method B).11) The treatment of 9a—g, i having
amine moieties with ethyl acetimidate and triethylamine af-
forded corresponding bisamidines 10a—g, i. The ester moi-
eties of 10d—f, i were hydrolyzed under acidic conditions to
give corresponding carboxylic acids 11d—f, i.
4 or 6-Substituted indoline derivatives (21, 22) were syn-
thesized as shown in Chart 3. 3-Nitrophenol (12) was con-
verted to intermediate 13 according to a method similar to
Fig. 1. Structure of the Indoline Derivative (R)-1
∗ To whom correspondence should be addressed. e-mail: naokit@sankyo.co.jp
© 2007 Pharmaceutical Society of Japan

394
Vol. 55, No. 3
Chart 1
Chart 2
Chart 3
that for 8a—g. Then, intermediate 13 was introduced to a scribed in Charts 1 and 2, anilines 17 and 18 were converted
trimethylsilylmethyl group to give two regioisomers (14, to corresponding compounds 21 and 22, which have 4 and 6-
15)12) which were separable from each other by using silica substituted indoline structures, respectively.
gel column chromatography.13) These two compounds (14,
5-Alkyl or 5-(methyl)aminoindoline derivatives (27, 33)
15) were coupled with 2-cyano-7-naphthylaldehyde (16)14) were synthesized as shown in Chart 4. 5-Hydroxyindoline
by tetrabutylammonium fluoride (TBAF), followed by reduc- compound (23)8) was converted to its trifluoromethanesul-
tion of the nitro group by catalytic hydrogenation to give ani- fonate 24.15) This compound was subjected to a Suzuki–
lines 17 and 18, respectively. By the same method as de- Miyaura cross coupling reaction16,17) with N-Boc-4-methyl-

March 2007
395
Chart 4
Chart 5
enepiperidine (25)18) to give compound 26, which has a we had succeeded in a multi-gram (ca. 10 g) synthesis of (S)-
methylene chain between the indoline ring and piperidine 3. Therefore, we considered that this synthetic route was ap-
ring. By the same method as described in Chart 2, compound plicable to the scale-up synthesis of (S)-3. The stereochem-
26 was converted to corresponding 5-alkylindoline derivative istry of (S)-3 was confirmed by a comparison with the same
27. Regarding the 5-(methyl)aminoindoline derivative,19) 4- compound reported in the previous paper.21) After the reac-
fluoro-1-nitrobenzene (28) was reacted with N-Boc-4- tion of (S)-3 with ethyl chlorosulfonylacetate,22) stereochemi-
aminopiperidine (29) under basic conditions, followed by the cally inversed intermediate (R)-8d was obtained according to
introduction of a methyl group on the nitrogen atom to give the same procedure as that for 8d. Optically active bisami-
intermediate 31. Compound 31 was converted to the corre- dine (R)-10d was synthesized from (R)-8d by the same
sponding 5-(methyl)aminoindoline derivative 33 by the same method as described in Chart 2. Moreover, carboxylic acid
procedures as described in Charts 1 and 2.
(R)-11d was synthesized by the acidic hydrolysis of (R)-10d.
The effective and practical synthesis of enantiomerically
pure intermediate (S)-3 without using chiral column chro- Results and Discussion
matography is outlined in Chart 5. Racemate 2 was reacted
The in vitro FXa inhibitory activities of all the compounds
with (S)-O-acetylmandel chloride20) to give mandelate 34 as synthesized were evaluated and expressed as IC50 values.
a diastereomixture. The diastereomixture was subjected to Based on the results of our previous report, we attempted fur-
crystallization (solvent: EtOAc/Et2Oꢁ1/20) to give optically ther optimization for each moiety of our indoline derivative.
pure mandelate (S)-34 having an S-configuration. Further- At first, we compared the effects of the position and the
more, to provide more (S)-34 we attempted to perform a linker atom of the piperidine ring to racemate (RS)-1 (Table
stereochemical inversion of the diastereomixture containing 1). Regarding for the substitution pattern of the central indo-
mainly (R)-34, rather than (S)-34 in the filtrate. The diastere- line ring, 5-substituted indoline compound (RS)-1 showed
omixture given from the filtrate was subjected to alcohol hy- higher FXa inhibitory activity than 4-substituted one 21 and
drolysis under basic conditions and a subsequent Mitsunobu 6-substituted one 22. In these three regioisomers, it seemed
reaction with (S)-O-acetylmandelic acid afforded the di- that 5-substituted compound is more favorable than the other
astereomixture containing (S)-34. The diastereomixture was two compounds. Regarding the linker structure of 5-substi-
subjected to crystallization (solvent: Et2O) to achieve an ad- tuted indoline compounds, we synthesized compounds hav-
ditional synthesis of mandelate (S)-34. After alcohol hydrol- ing a methylene group (27) or methylamino group (33) in-
ysis of mandelate (S)-34, the nitro group was reduced to give stead of an oxygen atom. Although both compounds showed
enantiomerically pure (>99% ee) alcohol (S)-3. At this point, good FXa inhibitory activities, the potencies were a little

396
Vol. 55, No. 3
Table 1. FXa Inhibitory Activity of Compounds (RS)-1, 21, 22, 27 and 33
Table 3. FXa Inhibitory Activity of Compounds (R)-1, (R)-10d and (R)-
11d
Compd.a)
Position
X
IC50 (nM)
Compd.a)
R
IC50 (nM)
(RS)-1
21
5-
4-
6-
5-
5-
O
O
O
CH2
NMe
11
27
140
22
(R)-1
(R)-10d
(R)-11d
SO2Et
SO2CH2CO2Et
SO2CH2CO2H
7.6
8.8
3.9
22
27
33
a) All compounds were synthesized and evaluated as their hydrochlorides.
17
a) All compounds were synthesized and evaluated as their hydrochlorides.
Table 4. Anticoagulant Activity of Compounds (R)-1 and (R)-11d
Table 2. FXa Inhibitory Activity of Compounds (RS)-1, 10a—d, 10g,
11d—f and 11i
CT2 (mM)a)
Compd.
Hamster
Human
(R)-1
(R)-11d
1.1
0.80
0.52
0.48
Compd.a)
R
IC50 (nM)
a) The concentration required to double clotting time.
(RS)-1
10a
10b
10c
10d
11d
11e
11f
SO2Et
SO2Me
SO2nBu
11
23
20
19
18
8.2
20
21
16
39
more potent FXa inhibitory activity than (RS)-1. We at-
tempted an acute toxicity test against these two compounds
and 10d (an ester form of 11d) in mice. All the mice died
immediately after administration of the compound (RS)-1 at
600 mg/kg (p.o.). This result suggests that the ethanesulfonyl
compound (RS)-1 has a serious adverse reaction. On the
other hand, all the mice survived with no lethal adverse reac-
tions after administration of 10d or 11d (600 mg/kg, p.o., re-
spectively).23) This result indicates that the substituent on the
nitrogen atom of the indoline ring is highly important not
SO2Ph
SO2CH2CO2Et
SO2CH2CO2H
SO2(CH2)3CO2H
SO2(CH2)5CO2H
COCH3
10g
11i
COCH2CO2H
a) All compounds were synthesized and evaluated as their hydrochlorides.
lower than that of (RS)-1. From these results, it seems that 5- only for efficacy but also for safety. Among the above com-
O-substitution is suitable for the linker structure between the pounds, 10d and 11d with polar functional groups on the ni-
indoline ring and the piperidine ring.
trogen atom showed favorable results in efficacy and safety.
Next, we focused on the substituent attached to the nitro-
We have reported that chiral compound (R)-1 showed
gen atom on the indoline ring and introduced various sub- more potent FXa inhibitory activity than the stereoisomer
stituents other than the ethanesulfonyl group and examined (S)-1. Based on this result, we synthesized the (R)-forms of
their FXa inhibitory activities (Table 2). Regarding the sul- 10d and 11d ((R)-10d and (R)-11d), to examine their in-
fonyl derivatives, both alkylsulfonyl compounds (10a, 10b) hibitory activities (Table 3). Both the two (R)-forms of 10d
showed potent FXa inhibitory activities. Compound 10c with and 11d showed more potent inhibitory activities than their
an aromatic ring also showed similar inhibitory activity to racemates. This result also suggests that the (R)-form is the
compounds 10a and 10b, though the activity was a slightly active form. Moreover, the activity of carboxylic acid (R)-
lower than (RS)-1. Then compounds with a polar functional 11d was superior to that of (R)-1. Therefore, (R)-11d is the
group introduced into the terminal carbon chain moieties best candidate of all the compounds described above.
(10d, 11d) were synthesized. Both compounds showed po-
We examined the effect of the in vitro anticoagulant activ-
tent FXa inhibitory activities superior to non-polar alkyl- or ity of prothrombin time (PT) in hamster and human plasma.
arylsulfonyl compounds. Furthermore, we studied the influ- Table 4 shows the CT2 values, the concentrations required to
ence of the length of the alkylene between the sulfonamide achieve 200% relative clotting time, of (R)-11d and (R)-1 in
group and the carboxyl group in 11d. Compounds 11e and hamster and human plasma (in vitro). Between these two
11f with longer carbon chains than that of 11d exhibited compounds, (R)-11d exhibited nearly equal or slightly more
lower inhibitory activity than 11d. In these three compounds potent activity in both hamster and human plasma than that
(11d—f), monomethylene compound 11d exhibited a favor- of (R)-1. In these in vitro tests, (R)-11d showed comparable
able result. The introduction of an acyl group instead of a activity to (R)-1 in FXa inhibition and anticoagulation.
sulfonyl group exhibited similar or lower FXa inhibitory ac-
We further evaluated the oral anticoagulant activity of (R)-
tivities (10g vs. 10a and 11i vs. 11d). These results suggest 11d. Table 5 shows the anticoagulant effect of (R)-11d in
that ethanesulfoyl ((RS)-1) and carboxymethysulfonyl (and hamsters, marmosets and cynomolgus monkeys (ex vivo,
its ester form) side chains are appropriate as substituents on p.o.). In each case, oral administration of (R)-11d prolonged
the nitrogen atom.
the prothrombin time in a dose-dependent manner. In partic-
Among the newly synthesized compounds, 11d showed ular, administration to marmosets showed a highly potent

March 2007
397
anticoagulant effect. The CT2 values, the dose required to pounds having more potent FXa inhibitory activities and
achieve 200% relative clotting time, of (R)-11d against ham- greater safety is underway.
sters, marmosets and cynomolgus monkeys were 38, 6.9 and
Experimental
18 mg/kg, respectively (ex vivo, 1 h). These results suggest
that (R)-11d exhibited potent anticoagulant activity both in
vitro and ex vivo.
1H-NMR spectra were obtained on a JEOL EX 270 or 400 MHz spectrom-
eter and are reported as d values relative to Me4Si as the internal standard.
1
Abbreviations of the H-NMR peak patterns are as follows: br sꢁbroad sin-
glet, sꢁsinglet, dꢁdoublet, ddꢁdouble doublet, tꢁtriplet, qꢁquartet, and
mꢁmultiplet. Merck Silica gel 60 (230—400 mesh) was used in the column
chromatography. Tetrahydrofuran, N,N-dimethylformamide, N,N-dimethyl-
acetamide, and dimethylsulfoxide are abbreviated as THF, DMF, DMA and
DMSO, respectively.
In conclusion, we synthesized many indoline compounds
and evaluated their FXa inhibitory activities. As a result, we
found some novel N-sulfonylindoline derivatives with high
FXa inhibitory activities. Among them, enantiomerically
pure (R)-11d with carboxymethylsulfonyl group on the nitro-
gen atom exhibited potent anticoagulant activities both in
vitro and ex vivo. Moreover, (R)-11d exhibited no lethal ad-
verse reaction after oral administration in mice (600 mg/kg,
p.o.). The substituent on the nitrogen atom of the indoline
ring is important for efficacy and safety. Compound (R)-11d
and some indoline derivatives are currently undergoing fur-
ther evaluation and synthetic efforts to explore novel com-
Ethyl ({[2-[2-(7-Cyanonaphthalen-2-yl)-2-hydroxyethyl]-4-(methoxy-
methoxy)phenyl]amino}sulfonyl)acetate (4d: R1ꢀSO2CH2CO2Et) To a
solution of 7-{2-[2-amino-5-(methoxymethoxy)phenyl]-1-hydroxyethyl}naph-
thalene-2-carbonitrile 3 (8.48 g, 24.4 mmol) in CH2Cl2 (180 ml) was added
EtO2CCH2SO2Cl (5.00 g, 26.8 mmol) in CH2Cl2 (20 ml) and pyridine
(2.17 ml, 26.8 mmol) and the mixture was stirred at room temperature for
1 h. H2O was added, and the mixture was extracted with CH2Cl2. The or-
ganic layer was washed with brine, dried and concentrated. The resulting
residue was chromatographed on a silica gel column (hexane/EtOAcꢁ1/1)
to give 4d (5.40 g, 10.8 mmol, 44%) as an amorphous solid. 1H-NMR
(CDCl3) d: 1.28 (3H, t, Jꢁ7.0 Hz), 3.12—3.21 (1H, m), 3.29—3.38 (1H,
m), 3.35 (3H, s), 4.02 (1H, d, Jꢁ15.0 Hz), 4.07 (1H, d, Jꢁ15.0 Hz), 4.27
(2H, q, Jꢁ7.0 Hz), 5.03 (1H, d, Jꢁ7.0 Hz), 5.07 (1H, d, Jꢁ7.0 Hz), 5.17—
5.24 (1H, m), 6.75 (1H, d, Jꢁ3.0 Hz), 6.93 (1H, dd, Jꢁ3.0, 9.0 Hz), 7.49
(1H, d, Jꢁ9.0 Hz), 7.60 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.70 (1H, dd, Jꢁ1.5,
8.5 Hz), 7.81—7.92 (3H, m), 8.19 (1H, br s).
Table 5. Anticoagulant Activity of Compound (R)-11d (ex vivo, p.o.)
PT (fold)
Dose
(mg/kg)
1 h
3 h
6 h
Ethyl {[2-(7-Cyanonaphthalen-2-yl)-5-(methoxymethoxy)indolin-1-yl]-
sulfonyl}acetate (5d: R1ꢀSO2CH2CO2Et) To a solution of ethyl ({[2-[2-
(7-cyanonaphthalen-2-yl)-2-hydroxyethyl]-4-(methoxymethoxy)phenyl]amino}-
sulfonyl)acetate 4d (5.39 g, 10.8 mmol) in THF (110 ml) was added n-Bu3P
(4.45 ml, 17.9 mmol) and ADDP (4.09 g, 16.2 mmol) in THF (40 ml) at 0 °C
and the mixture was stirred at room temperature for 1.5 h. The mixture was
allowed to stand overnight, and the precipitate was filtered away. NH4Cl
(100 ml) 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/EtOAcꢁ11/9) to give
5d (4.85 g, 10.1 mmol, 93%) as an amorphous solid. 1H-NMR (CDCl3) d
1.28 (3H, t, Jꢁ7.0 Hz), 3.05 (1H, dd, Jꢁ2.5, 16.0 Hz), 3.49 (3H, s), 3.92—
Hamstera)
30
1.5
3.7
1.2
2.1
1.0
1.2
100
Marmoseta)
10
30
2.3
8.7
1.8
6.9
1.5
4.1
Cynomolgus monkeyb)
10
30
1.6
2.6
1.7
3.0
1.3
2.3
a) nꢁ4. b) nꢁ3.
Table 6. Physical Data for Indoline Derivatives
Analysis (%) Calcd (Found)
Compd.
Formula
C
H
N
Cl
S
10a
10b
10c
10d
10g
11d
11e
11f
11i
21
C27H31N5O3S·2.0HCl·2.0H2O
C30H37N5O3S·2.0HCl·2.5H2O
C32H33N5O3S·1.9HCl·1.9H2O
C30H35N5O5S·2.0HCl·3.0H2O
C28H31N5O2·2.0HCl·1.7H2O
C28H31N5O5S·2.0HCl·0.8H2O
C30H35N5O5S·1.7HCl·3.5H2O
C32H39N5O5S·2.1HCl·1.1H2O
C29H31N5O4·2.8HCl·1.8H2O
C28H33N5O3S·2.5HCl·2.3H2O
C28H33N5O3S·2.5HCl·2.5H2O
C29H35N5O2S·2.3HCl·3.0H2O
C29H36N6O2S·3.7HCl·2.9H2O
52.77
(53.08)
54.13
(54.32)
57.26
(57.45)
51.13
(51.00)
58.68
(58.32)
52.80
(53.08)
51.28
(51.04)
54.60
(54.28)
53.74
(53.43)
51.56
(51.53)
51.28
(51.38)
53.13
(53.22)
48.39
6.07
(6.28)
6.66
(6.70)
5.81
(6.07)
6.15
(5.76)
6.40
(6.77)
5.48
(5.81)
6.27
(6.01)
6.23
(6.01)
5.82
(6.00)
6.20
(6.17)
6.22
(6.28)
6.66
(6.56)
6.37
11.40
(11.10)
10.52
(10.25)
10.45
(10.13)
9.94
(9.99)
12.22
(12.31)
10.99
(11.02)
9.97
(10.06)
9.95
(10.15)
10.81
(11.16)
10.74
(10.67)
10.68
(10.69)
10.68
(10.62)
11.67
11.54
(11.25)
10.65
(10.68)
10.04
(9.87)
10.06
(10.18)
12.37
(12.70)
11.13
(11.12)
8.58
(8.39)
10.58
(10.60)
15.32
(15.50)
13.59
(13.58)
13.51
(13.22)
12.44
(12.48)
18.22
5.22
(5.08)
4.82
(4.66)
4.78
(4.72)
4.55
(4.90)
—
5.03
(5.05)
4.56
(4.94)
4.55
(4.38)
—
4.92
(4.95)
4.89
(5.15)
4.89
22
27
(4.88)
4.45
33
(48.37)
(6.05)
(11.68)
(18.29)
(4.61)

398
Vol. 55, No. 3
Table 7. Physical Data for Indoline Derivatives
Compd.
1H-NMR d (DMSO-d6)
10a
1.63—1.83 (2H, m), 1.93—2.11 (2H, m), 2.30 (3H, s), 2.95—3.08 (1H, m), 3.02 (3H, s), 3.44—3.64 (2H, m), 3.66—3.87 (2H, m), 3.96 (1H, dd,
Jꢁ10.0, 17.0 Hz), 4.59—4.69 (1H, m), 5.77 (1H, dd, Jꢁ2.5, 10.0 Hz), 6.94 (1H, dd, Jꢁ2.0, 9.0 Hz), 7.01 (1H, d, Jꢁ2.0 Hz), 7.36 (1H, d,
Jꢁ9.0 Hz), 7.65 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.84 (1H, dd, Jꢁ2.0, 8.5 Hz), 7.97 (1H, br s), 8.08 (1H, d, Jꢁ9.0 Hz), 8.13 (1H, d, Jꢁ8.5 Hz), 8.52
(1H, br s)
10b
0.82 (3H, t, Jꢁ7.5 Hz), 1.28—1.40 (2H, m), 1.55—1.80 (4H, m), 1.95—2.09 (2H, m), 2.30 (3H, s), 2.95—3.12 (2H, m), 3.19—4.05 (5H, m),
3.92 (1H, dd, Jꢁ10.0, 16.5 Hz), 4.56—4.68 (1H, m), 5.79 (1H, dd, Jꢁ3.0, 10.0 Hz), 6.93 (1H, dd, Jꢁ2.0, 9.0 Hz), 7.00 (1H, d, Jꢁ2.0 Hz), 7.35
(1H, d, Jꢁ9.0 Hz), 7.64 (1H, dd, Jꢁ1.0, 8.5 Hz), 7.79—7.88 (1H, m), 7.96 (1H, br s), 8.08 (1H, d, Jꢁ8.5 Hz), 8.13 (1H, d, Jꢁ8.5 Hz), 8.51 (1H,
br s)
10c
10d
10g
11d
11e
11f
11i
21
1.57—1.79 (2H, m), 1.93—2.07 (2H, m), 2.28 (3H, s), 2.86 (1H, dd, Jꢁ2.5, 17.0 Hz), 3.25 (1H, dd, Jꢁ10.0, 17.0 Hz), 3.15—3.88 (4H, m),
4.52—4.65 (1H, m), 5.77 (1H, dd, Jꢁ2.5, 10.0 Hz), 6.84 (1H, d, Jꢁ2.0 Hz), 6.95 (1H, dd, Jꢁ2.0, 8.5 Hz), 7.52—7.90 (8H, m), 8.05 (1H, br s),
8.08 (1H, d, Jꢁ8.5 Hz), 8.14 (1H, d, Jꢁ8.5 Hz), 8.52 (1H, br s)
1.12 (3H, t, Jꢁ7.0 Hz), 1.62—1.82 (2H, m), 1.96—2.12 (2H, m), 2.30 (3H, s), 2.96—3.07 (1H, m), 3.32—4.11 (7H, m), 4.38 (1H, d,
Jꢁ14.0 Hz), 4.52 (1H, d, Jꢁ14.0 Hz), 4.59—4.69 (1H, m), 5.88 (1H, d, Jꢁ10.0 Hz), 6.95 (1H, d, Jꢁ9.0 Hz), 7.02 (1H, br s), 7.35 (1H, d,
Jꢁ9.0 Hz), 7.64 (1H, d, Jꢁ8.5 Hz), 7.86 (1H, d, Jꢁ8.5 Hz), 7.94 (1H, br s), 8.08 (1H, d, Jꢁ8.5 Hz), 8.13 (1H, d, Jꢁ8.5 Hz), 8.52 (1H, br s)
1.60—1.80 (2H, m), 1.89—2.10 (2H, m), 1.95 (3H, s), 2.30 (3H, s), 2.91 (1H, d, Jꢁ16.0 Hz), 3.45—3.94 (5H, m), 4.55—4.67 (1H, m), 5.91
(1H, d, Jꢁ9.0 Hz), 6.86—6.96 (2H, m), 7.59 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.76 (1H, br s), 7.85 (1H, d, Jꢁ8.5 Hz), 8.04—8.19 (3H, m), 8.48 (1H,
br s)
1.63—1.85 (2H, m), 1.96—2.15 (2H, m), 2.30 (3H, s), 3.00 (1H, d, Jꢁ16.0 Hz), 3.44—4.23 (5H, m), 4.12 (1H, d, Jꢁ14.0 Hz), 4.42 (1H, d,
Jꢁ14.0 Hz), 4.58—4.72 (1H, m), 5.85 (1H, d, Jꢁ8.5 Hz), 6.95 (1H, d, Jꢁ8.5 Hz), 7.00 (1H, br s), 7.36 (1H, d, Jꢁ8.5 Hz), 7.64 (1H, d,
Jꢁ8.5 Hz), 7.85 (1H, d, Jꢁ8.5 Hz), 7.95 (1H, br s), 8.08 (1H, d, Jꢁ8.5 Hz), 8.13 (1H, d, Jꢁ8.5 Hz), 8.52 (1H, br s)
1.63—2.15 (6H, m), 2.29 (3H, s), 2.35 (2H, t, Jꢁ7.0 Hz), 2.93—3.89 (7H, m), 3.97 (1H, dd, Jꢁ10.0, 17.0 Hz), 4.56—4.69 (1H, m), 5.76 (1H,
dd, Jꢁ2.5, 10.0 Hz), 6.85—7.05 (2H, m), 7.35 (1H, d, Jꢁ9.0 Hz), 7.65 (1H, dd, Jꢁ1.0, 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)
1.24—1.84 (8H, m), 1.94—2.20 (2H, m), 2,14 (2H, t, Jꢁ7.0 Hz), 2.29 (3H, s), 2.94—3.89 (7H, m), 3.96 (1H, dd, Jꢁ10.0, 16.5 Hz), 4.55—4.69
(1H, m), 5.79 (1H, dd, Jꢁ2.5, 10.0 Hz), 6.92 (1H, dd, Jꢁ2.0, 9.0 Hz), 6.98 (1H, br s), 7.35 (1H, d, Jꢁ8.5 Hz), 7.64 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.84
(1H, d, Jꢁ8.5 Hz), 7.96 (1H, br s), 8.07 (1H, d, Jꢁ8.5 Hz), 8.13 (1H, d, Jꢁ8.5 Hz), 8.50 (1H, br s)
1.63—1.81 (2H, m), 1.95—2.10 (2H, m), 2.30 (3H, s), 2.92 (1H, d, Jꢁ16.0 Hz), 3.27—3.92 (6H, m), 4.34 (1H, d, Jꢁ16.0 Hz), 4.58—4.67 (1H,
m), 5.89 (1H, d, Jꢁ9.5 Hz), 6.92—6.98 (2H, m), 7.57 (1H, d, Jꢁ8.5 Hz), 7.76 (1H, br s), 7.86 (1H, d, Jꢁ8.5 Hz), 8.06—8.22 (3H, m), 8.47 (1H,
br s)
1.17 (3H, t, Jꢁ7.5 Hz), 1.61—1.80 (2H, m), 1.89—2.08 (2H, m), 2.25, 2.27 (together 3H, each singlet), 2.85—2.97 (1H, m), 3.05—3.90 (7H,
m), 4.69—4.79 (1H, m), 5.81 (1H, dd, Jꢁ2.0, 10.0 Hz), 6.86 (1H, d, Jꢁ8.0 Hz), 7.06 (1H, d, Jꢁ8.0 Hz), 7.26 (1H, t, Jꢁ8.0 Hz), 7.63 (1H, d,
Jꢁ8.5 Hz), 7.85 (1H, d, Jꢁ8.5 Hz), 7.94 (1H, br s), 8.04—8.14 (2H, m), 8.52 (1H, br s)
22
1.17 (3H, t, Jꢁ7.0 Hz), 1.69—1.87 (2H, m), 1.96—2.12 (2H, m), 2.30 (3H, s), 2.90—2.99 (1H, m), 3.11—3.91 (7H, m), 4.62—4.72 (1H, m),
5.78 (1H, dd, Jꢁ2.0, 10.5 Hz), 6.76 (1H, d, Jꢁ8.5 Hz), 7.01 (1H, br s), 7.18 (1H, d, Jꢁ8.5 Hz), 7.61 (1H, d, Jꢁ8.5 Hz), 7.82 (1H, d, Jꢁ8.0 Hz),
7.93 (1H, br s), 8.06 (1H, d, Jꢁ8.5 Hz), 8.11 (1H, d, Jꢁ8.5 Hz), 8.48 (1H, br s)
27
33
1.09—1.31 (5H, m), 1.60—1.92 (3H, m), 2.24 (3H, s), 2.94—3.46 (7H, m), 3.80—4.15 (3H, m), 5.78 (1H, dd, Jꢁ3.0, 10.5 Hz), 7.06—7.12 (2H,
m), 7.35 (1H, d, Jꢁ8.5 Hz), 7.62 (1H, d, Jꢁ8.5 Hz), 7.83 (1H, d, Jꢁ8.5 Hz), 7.95 (1H, br s), 8.04—8.15 (2H, m), 8.49 (1H, br s)
1.19 (3H, t, Jꢁ7.5 Hz), 1.63—1.95 (4H, m), 2.28 (3H, s), 2.75—4.05 (11H, m), 4.18—4.32 (1H, m), 5.76—5.84 (1H, m), 7.27—7.50 (3H, m),
7.65 (1H, d, Jꢁ8.5 Hz), 7.84 (1H, d, Jꢁ8.5 Hz), 7.97 (1H, br s), 8.06—8.16 (2H, m), 8.50 (1H, br s)
4.27 (3H, m), 3.99 (1H, d, Jꢁ14.5 Hz), 4.06 (1H, d, Jꢁ14.5 Hz), 5.14 (2H,
column (hexane/EtOAcꢁ3/2) to give 8d (1.11 g, 1.79 mmol, 78%) as an
s), 5.80 (1H, dd, Jꢁ2.5, 10.0 Hz), 6.90—7.01 (2H, m), 7.45 (1H, d, amorphous solid. 1H-NMR (CDCl3) d: 1.28 (3H, t, Jꢁ7.0 Hz), 1.47 (9H, s),
Jꢁ9.0 Hz), 7.57 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.58 (1H, dd, Jꢁ1.5, 8.5 Hz),
7.81—7.92 (3H, m), 8.15 (1H, br s).
1.67—1.80 (2H, m), 1.85—1.96 (2H, m), 3.04 (1H, dd, Jꢁ2.5, 16.0 Hz),
3.27—3.38 (2H, m), 3.65—3.75 (2H, m), 3.98 (1H, d, Jꢁ14.0 Hz), 4.01—
Ethyl {[2-(7-Cyanonaphthalen-2-yl)-5-hydroxyindolin-1-yl]sulfonyl}- 4.12 (1H, m), 4.05 (1H, d, Jꢁ14.0 Hz), 4.15—4.25 (2H, m), 4.36—4.44
acetate (6d: R1ꢀSO2CH2CO2Et) To a suspension of ethyl {[2-(7-cy- (1H, m), 5.79 (1H, dd, Jꢁ2.5, 10.0 Hz), 6.78—6.86 (2H, m), 7.44 (1H, d,
anonaphthalen-2-yl)-5-(methoxymethoxy)indoline-1-yl]sulfonyl}acetate 5d
(4.83 g, 10.1 mmol) in EtOAc (40 ml) was added a 4 N solution of hydrogen
chloride in EtOAc (20 ml, 80 mmol) at 0 °C and the mixture was stirred at
room temperature for 1 h. The mixture was allowed to stand overnight and 3.10 (1H, dd, Jꢁ3.5, 16.5 Hz), 3.25—3.39 (2H, m), 3.61—3.80 (2H, m),
concentrated. The resulting residue was chromatographed on a silica gel col- 3.86 (1H, dd, Jꢁ10.0, 16.5 Hz), 4.34—4.48 (1H, m), 5.56 (1H, dd, Jꢁ3.5,
Jꢁ8.5 Hz), 7.54—7.62 (2H, m), 7.82—7.91 (3H, m), 8.20 (1H, br s).
Similarly, compounds 8a—c, 8e—g were prepared.
8a: H-NMR (CDCl3) d: 1.46 (9H, s), 1.59—2.01 (4H, m), 2.81 (3H, s),
1
umn (hexane/EtOAcꢁ1/1) to give 6d (4.21 g, 9.65 mmol, 96%) as an amor-
10.0 Hz), 6.75—6.92 (2H, m), 7.45 (1H, d, Jꢁ8.5 Hz), 7.54—7.67 (2H, m),
phous solid. 1H-NMR (CDCl3) d: 1.28 (3H, t, Jꢁ7.0 Hz), 3.03 (1H, dd, 7.79—7.96 (3H, m), 8.20 (1H, br s).
Jꢁ2.5, 16.0 Hz), 3.89—4.23 (3H, m), 3.99 (1H, d, Jꢁ14.5 Hz), 4.05 (1H, d,
Jꢁ14.5 Hz), 5.78 (1H, dd, Jꢁ2.5, 10.0 Hz), 6.69—6.80 (2H, m), 7.40 (1H, 1.47 (9H, s), 2.80—3.05 (2H, m), 3.08 (1H, dd, Jꢁ3.0, 16.5 Hz), 3.25—3.39
8b: 1H-NMR (CDCl3) d: 0.84 (3H, t, Jꢁ7.5 Hz), 1.18—2.01 (8H, m),
d, Jꢁ9.5 Hz), 7.48—7.59 (2H, m), 7.76—7.87 (3H, m), 8.19 (1H, br s).
(2H, m), 3.61—3.80 (2H, m), 3.86 (1H, dd, Jꢁ10.0, 16.5 Hz), 4.31—4.49
Ethyl ({5-[1-(t-Butoxycarbonyl)piperidin-4-yloxy]-2-(7-cyanonaphtha- (1H, m), 5.61 (1H, dd, Jꢁ3.0, 10.0 Hz), 6.73—6.91 (2H, m), 7.42 (1H, d,
len-2-yl)indolin-1-yl}sulfonyl)acetate (8d: R1ꢀSO2CH2CO2Et) Diethyl Jꢁ8.5 Hz), 7.51—7.65 (2H, m), 7.80—7.93 (3H, m), 8.21 (1H, br s).
1
azodicarboxylate (DEAD) (0.54 ml, 3.43 mmol) was added to a solution of
8c: H-NMR (CDCl3) d: 1.46 (9H, s), 1.54—1.98 (4H, m), 2.84 (1H, dd,
ethyl {[2-(7-cyanonaphthalen-2-yl)-5-hydroxyindoline-1-yl]sulfonyl}acetate Jꢁ3.0, 16.5 Hz), 3.11—3.42 (3H, m), 3.58—3.79 (2H, m), 4.27—4.43 (1H,
6d (1.00 g, 2.29 mmol), 1-(t-butoxycarbonyl)-4-hydroxypiperidine 7 (692
mg, 3.44 mmol) and PPh3 (901 mg, 3.43 mmol) in THF (20 ml), and the re-
m), 5.64 (1H, dd, Jꢁ3.0, 10.0 Hz), 6.62 (1H, d, Jꢁ2.5 Hz), 6.85 (1H, dd,
Jꢁ2.5, 9.0 Hz), 7.33—7.45 (2H, m), 7.48—7.64 (3H, m), 7.66—7.75 (3H,
sulting mixture was stirred overnight at room temperature. To the reaction m), 7.78—7.90 (3H, m), 8.19 (1H, br s).
mixture were added DEAD (0.360 ml, 2.29 mmol), 7 (461 mg, 2.29 mmol)
and PPh3 (601 mg, 2.29 mmol), and the resulting mixture was stirred at room
8e: 1H-NMR (CDCl3) d: 1.26 (3H, t, Jꢁ7.0 Hz), 1.45 (9H, s), 1.47—2.00
(6H, m), 2.02—2.22 (2H, m), 2.30—2.51 (2H, m), 2.94—3.15 (3H, m),
temperature for 2 h and stored overnight. H2O was added, and the mixture 3.23—3.40 (2H, m), 3.59—3.79 (2H, m), 3.88 (1H, dd, Jꢁ10.5, 16.5 Hz),
was extracted with EtOAc. The organic layer was washed with brine, dried 4.12 (2H, q, Jꢁ7.0 Hz), 4.32—4.48 (1H, m), 5.61 (1H, dd, Jꢁ3.0, 10.5 Hz),
and concentrated. The resulting residue was chromatographed on a silica gel 6.75—6.91 (2H, m), 7.42 (1H, d, Jꢁ8.5 Hz), 7.50—7.65 (2H, m), 7.79—

March 2007
399
7.96 (3H, m), 8.21 (1H, br s).
2.78—3.40 (6H, m), 4.45—4.57 (1H, m), 5.77 (1H, dd, Jꢁ3.0, 10.0 Hz),
6.83 (1H, d, Jꢁ2.0 Hz), 6.94 (1H, dd, Jꢁ2.0, 9.0 Hz), 7.48—7.61 (3H, m),
7.65—7.88 (5H, m), 8.05 (1H, br s), 8.08 (1H, d, Jꢁ8.5 Hz), 8.14 (1H, d,
Jꢁ8.5 Hz), 8.52 (1H, br s).
8f: 1H-NMR (CDCl3) d: 1.24 (3H, t, Jꢁ7.0 Hz), 1.32—1.99 (10H, m),
1.47 (9H, s), 2.24 (2H, t, Jꢁ7.5 Hz), 2.78—3.11 (2H, m), 3.08 (1H, dd,
Jꢁ3.0, 16.5 Hz), 3.27—3.42 (2H, m), 3.61—3.79 (2H, m), 3.85 (1H, dd,
Jꢁ10.0, 16.5 Hz), 4.11 (2H, t, Jꢁ7.0 Hz), 4.32—4.44 (1H, m), 5.60 (1H, dd,
Jꢁ3.0, 10.0 Hz), 6.76—6.90 (2H, m), 7.41 (1H, d, Jꢁ8.5 Hz), 7.55—7.66
(2H, m), 7.79—7.94 (3H, m), 8.20 (1H, br s).
1
9e: H-NMR (DMSO-d6) d: 1.14 (3H, t, Jꢁ7.0 Hz), 1.71—2.23 (6H, m),
2.42 (2H, t, Jꢁ7.0 Hz), 2.79—3.39 (7H, m), 3.90—4.11 (1H, m), 4.02 (2H,
q, Jꢁ7.0 Hz), 4.45—4.63 (1H, m), 5.67—5.84 (1H, m), 6.85—7.03 (2H, m),
7.34 (1H, d, Jꢁ9.0 Hz), 7.61—7.70 (1H, m), 7.80—7.90 (1H, m), 7.95 (1H,
br s), 8.07 (1H, d, Jꢁ8.5 Hz), 8.13 (1H, d, Jꢁ8.5 Hz), 8.49 (1H, br s).
1
8g: H-NMR (CDCl3) d: 1.46 (9H, s), 1.59—1.98 (4H, m), 2.05 (3H, s),
2.97 (1H, dd, Jꢁ1.5, 16.0 Hz), 3.21—3.40 (2H, m), 3.60—3.78 (2H, m),
3.87 (1H, dd, Jꢁ9.5, 16.0 Hz), 4.35—4.43 (1H, m), 5.49—5.64 (1H, m),
6.65—6.88 (2H, m), 7.46 (1H, d, Jꢁ8.5 Hz), 7.61 (1H, d, Jꢁ8.5 Hz), 7.66
(1H, br s), 7.80—7.93 (2H, m), 8.17 (1H, br s), 8.27 (1H, d, Jꢁ8.5 Hz).
Ethyl 3-{5-[1-(t-Butoxycarbonyl)piperidin-4-yloxy]-2-(7-cyanonaph-
thalen-2-yl)indolin-1-yl}-3-oxopropionate (8i) A solution of 1-(benzyl-
oxycarbonyl)-5-[1-(t-butoxycarbonyl)piperidin-4-yloxy]-2-(7-cyanonaph-
thalen-2-yl)indoline 8h (6.00 g, 9.94 mmol) in THF (30 ml) and EtOH
(30 ml) was hydrogenated over 10% Pd–C (1.2 g) at room temperature for
4 h with stirring. The catalyst was filtered away, and the filtrate was concen-
trated. The resulting residue was chromatographed on a silica gel column
(CH2Cl2/EtOAcꢁ20/1) to give 5-[1-(t-butoxycarbonyl)piperidin-4-yloxy]-2-
(7-cyanonaphthalen-2-yl)indoline (4.16 g, 8.86 mmol, 89%) as pale yellow
crystals. This crystal (1.50 g, 3.19 mmol) was dissolved in CH2Cl2 (20 ml)
and treated with ethyl malonyl chloride (0.49 ml, 3.83 mmol) and pyridine
(0.26 ml, 3.21 mmol) at ꢂ10 °C. The resulting mixture was stirred at the
same temperature for 2 h and at room temperature for 1 h. The reaction mix-
ture was concentrated and to the resulting residue was added H2O. The mix-
ture was extracted with EtOAc and washed with H2O and brine. The organic
layer was dried and concentrated. The resulting residue was chroma-
tographed on a silica gel column (hexane/EtOAcꢁ1/1) to give 8i (1.46 g,
1
9f: H-NMR (DMSO-d6) d: 1.16 (3H, t, Jꢁ7.0 Hz), 1.25—1.98 (8H, m),
1.99—2.18 (2H, m), 2.21 (2H, t, Jꢁ7.0 Hz), 2.78—3.40 (7H, m), 3.95 (1H,
dd, Jꢁ10.5, 17.0 Hz), 4.03 (2H, q, Jꢁ7.0 Hz), 4.48—4.62 (1H, m), 5.78
(1H, dd, Jꢁ2.5, 10.5 Hz), 6.86—6.98 (2H, m), 7.34 (1H, d, Jꢁ8.5 Hz), 7.64
(1H, dd, Jꢁ1.5, 8.5 Hz), 7.82 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.95 (1H, d,
Jꢁ1.5 Hz), 8.07 (1H, d, Jꢁ8.5 Hz), 8.13 (1H, d, Jꢁ8.5 Hz), 8.49 (1H, d,
Jꢁ1.5 Hz).
1-Acetyl-2-(7-amidinonaphthalen-2-yl)-5-(piperidin-4-yloxy)indoline
Dihydrochloride (9g: R1ꢀAc) (Method B) To a solution of 1-acetyl-5-
[1-(t-butoxycarbonyl)piperidin-4-yloxy]-2-(7-cyanonaphthalen-2-yl)indoline
8g (1.14 g, 2.23 mmol) in MeOH (20 ml) were added hydroxylamine hy-
drochloride (510 mg, 7.34 mmol) and Na2CO3 (350 mg, 3.30 mmol), and the
resulting mixture was stirred at 80 °C for 12 h. The reaction mixture was
concentrated and to the residue was added H2O. The resulting precipitate
was filtered to give a colorless solid. This solid was dissolved in AcOH
(20 ml) and treated with Ac2O (0.30 ml, 3.17 mmol). After stirring at room
temperature for 20 min, the mixture was hydrogenated over 10% Pd–C
(150 mg) at room temperature for 10 h while stirring. The catalyst was fil-
tered away, and the filtrate was concentrated. The resulting residue was chro-
matographed on a silica gel column (ChromatorexTM ‘NH’, Fuji Chemical
Ltd., CH2Cl2/MeOHꢁ9/1) to give the free base of 9g (843 mg, 1.97 mmol)
as an amorphous solid. This amorphous solid was dissolved in EtOAc
(25 ml) and treated with a 4 N solution of hydrogen chloride in EtOAc
(10.6 ml, 42.4 mmol). The mixture was stirred at room temperature for 3 h
and the resulting precipitate was filtered to give 9g (817 mg, 1.63 mmol,
1
2.50 mmol, 78%) as a pale yellow solid. H-NMR (CDCl3) d: 1.19 (3H, t,
Jꢁ7.0 Hz), 1.46 (9H, s), 1.67—1.77 (2H, m), 1.84—1.95 (2H, m), 2.99 (1H,
dd, Jꢁ1.5, 16.0 Hz), 3.19 (1H, d, Jꢁ15.0 Hz), 3.27—3.36 (2H, m), 3.42
(1H, d, Jꢁ15.0 Hz), 3.64—3.73 (2H, m), 3.89 (1H, dd, Jꢁ10.0, 16.0 Hz),
4.08 (2H, q, Jꢁ7.0 Hz), 4.36—4.45 (1H, m), 5.67 (1H, dd, Jꢁ1.5, 10.0 Hz),
6.72 (1H, d, Jꢁ2.0 Hz), 6.86 (1H. dd, Jꢁ2.0, 9.0 Hz), 7.45 (1H, dd, Jꢁ1.5,
8.5 Hz), 7.62 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.67 (1H, br s), 7.89 (1H, d,
Jꢁ8.5 Hz), 7.90 (1H, d, Jꢁ8.5 Hz), 8.18 (1H, br s), 8.28 (1H, d, Jꢁ9.0 Hz).
Ethyl {[2-(7-Amidinonaphthalen-2-yl)-5-(piperidin-4-yloxy)indolin-1-
yl]sulfonyl}acetate Dihydrochloride (9d: R1ꢀSO2CH2CO2Et) (Method
A) Into a solution of ethyl ({5-[1-(t-butoxycarbonyl)piperidin-4-yloxy]-
2-(7-cyanonaphthalen-2-yl)indolin-1-yl}sulfonyl)acetate 8d (790 mg, 1.27
mmol) in CH2Cl2 (10 ml) and EtOH (10 ml) was bubbled hydrogen chloride
under ice-cooling, and the resulting mixture was stirred at room temperature
under tightly sealed condition for 3 h. The reaction mixture was concen-
trated. The resulting residue was dissolved in EtOH (15 ml) and the solution
was treated with NH4Cl (123 mg, 2.30 mmol) in H2O (5 ml) and NH3 solu-
tion (0.260 ml, 4.27 mmol). The mixture was allowed to stand at room tem-
perature overnight and concentrated. The resulting residue was chro-
matographed on a silica gel column (Cosmosil 75C18-PREPTM, Nacalai
Tesque Inc., MeCN/H2Oꢁ3/97—1/9) to give the free base of 9d, (528 mg,
0.983 mmol, 77%) as an amorphous solid. This amorphous solid (49 mg,
0.091 mmol) was dissolved in EtOH (3 ml) and treated with a 4 N solution of
hydrogen chloride in EtOAc (0.068 ml, 0.27 mmol). The mixture was con-
centrated and the resulting residue was dried at 70 °C to give 9d (53 mg,
0.087 mmol) as an amorphous solid. 1H-NMR (DMSO-d6) d: 1.12 (3H, t,
Jꢁ7.0 Hz), 1.73—1.88 (2H, m), 2.02—2.14 (2H, m), 2.97—3.39 (5H, m),
3.88—4.10 (3H, m), 4.37 (1H, d, Jꢁ14.0 Hz), 4.47—4.62 (1H, m), 4.51
(1H, d, Jꢁ14.0 Hz), 5.87 (1H, d, Jꢁ10.0 Hz), 6.94 (1H, d, Jꢁ9.0 Hz), 7.00
(1H, br s), 7.35 (1H, d, Jꢁ9.0 Hz), 7.64 (1H, d, Jꢁ8.5 Hz), 7.83 (1H, d,
Jꢁ8.5 Hz), 7.94 (1H, br s), 8.08 (1H, d, Jꢁ8.5 Hz), 8.13 (1H, d, Jꢁ8.5 Hz),
8.50 (1H, br s).
1
73%) as an amorphous solid. H-NMR (DMSO-d6) d: 1.72—2.16 (4H, m),
1.95 (3H, s), 2.84—3.28 (5H, m), 3.87 (1H, dd, Jꢁ10.0, 16.5 Hz), 4.47—
4.63 (1H, m), 5.86—5.96 (1H, m), 6.85—6.97 (2H, m), 7.55—7.64 (1H, m),
7.75 (1H, br s), 7.83 (1H, d, Jꢁ8.5 Hz), 8.03—8.21 (3H, m), 8.46 (1H, br s).
Similarly, compound 9i was prepared.
1
9i: H-NMR (DMSO-d6) d: 1.03 (3H, t, Jꢁ7.0 Hz), 1.77—1.89 (2H, m),
2.02—2.18 (2H, m), 2.92 (1H, d, Jꢁ16.5 Hz), 2.97—3.08 (2H, m), 3.10
(1H, d, Jꢁ16.0 Hz), 3.15—3.27 (2H, m), 3.71 (1H, d, Jꢁ16.0 Hz), 3.74—
4.00 (3H, m), 4.49—4.65 (1H, m), 5.94 (1H, d, Jꢁ9.0 Hz), 6.88—6.99 (2H,
m), 7.57 (1H, d, Jꢁ8.5 Hz), 7.77 (1H, s), 7.84 (1H, d, Jꢁ8.5 Hz), 8.05—
8.22 (3H, m), 8.46 (1H, s).
Ethyl ({5-[1-(Acetimidoyl)piperidin-4-yloxy]-2-(7-amidinonaphthalen-2-
yl)indolin-1-yl}sulfonyl)acetate Dihydrochloride (10d: R1ꢀSO2CH2CO2Et)
To a solution of ethyl {[2-(7-amidinonaphthalen-2-yl)-5-(piperidin-4-yl-
oxy)indolin-1-yl]sulfonyl}acetate dihydrochloride 9d (460 mg, 0.755 mmol)
in EtOH (12 ml) were added ethyl acetimidate hydrochloride (233 mg,
1.89 mmol) and Et3N (0.390 ml, 2.81 mmol). The resulting mixture was
stirred at room temperature for 4 h and allowed to stand overnight. Ethyl
acetimidate hydrochloride (106 mg, 0.858 mmol) and Et3N (0.24 ml,
1.73 mmol) were added, and the mixture was stirred overnight at room tem-
perature. The reaction mixture was concentrated and the resulting residue
was purified by preparative HPLC (TSK gel ODS-80Ts, Tosoh Corp.,
H2O/MeCNꢁ9/1) to give the free base of 10d (325 mg, 0.563 mmol) as an
amorphous solid. This amorphous solid (55 mg) was dissolved in EtOH
(4 ml) and treated with a 4 N solution of hydrogen chloride in dioxane
(0.071 ml, 0.284 mmol). The mixture was stored at room temperature for
5 min and concentrated. The resulting residue was dried overnight at 70 °C
to give 10d (60 mg, 0.092 mmol, 72%) as an amorphous solid.
Similarly, compounds 9a—c, 9e and 9f were prepared.
9a: 1H-NMR (DMSO-d6) d: 1.76—1.95 (2H, m), 1.99—2.19 (2H, m),
2.78—3.41 (5H, m), 3.01 (3H, s), 3.96 (1H, dd, Jꢁ10.0, 17.0 Hz), 4.50—
4.65 (1H, m), 5.76 (1H, dd, Jꢁ3.0, 10.0 Hz), 6.89—7.03 (2H, m), 7.35 (1H,
d, Jꢁ8.5 Hz), 7.65 (1H, d, Jꢁ8.5 Hz), 7.82 (1H, d, Jꢁ8.5 Hz), 7.97 (1H,
br s), 8.08 (1H, d, Jꢁ8.5 Hz), 8.13 (1H, d, Jꢁ8.5 Hz), 8.50 (1H, br s).
9b: 1H-NMR (DMSO-d6) d: 0.81 (3H, t, Jꢁ7.5 Hz), 1.25—1.45 (2H, m),
1.54—1.70 (2H, m), 1.75—1.88 (2H, m), 1.98—2.15 (2H, m), 2.97—3.41
(7H, m), 3.96 (1H, dd, Jꢁ10.0, 17.0 Hz), 4.48—4.65 (1H, m), 5.70—5.82
(1H, m), 6.85—7.02 (2H, m), 7.34 (1H, d, Jꢁ8.5 Hz), 7.64 (1H, d,
Jꢁ8.5 Hz), 7.83 (1H, d, Jꢁ8.5 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).
Similarly, other bisamidine derivatives 10a—c, 10g were prepared.
({5-[1-(Acetimidoyl)piperidin-4-yloxy]-2-(7-amidinonaphthalen-2-yl)-
indolin-1-yl}sulfonyl)acetic acid Dihydrochloride (11a: R1ꢀSO2CH2CO2H)
Ethyl (5-{[1-(acetimidoyl)piperidin-4-yloxy]-2-(7-amidinonaphthalen-2-
yl)indolin-1-yl}sulfonyl)acetate dihydrochloride 10d (261 mg, 0.452 mmol)
was dissolved in a solution of 1 N hydrogen chloride (10 ml) and stirred at
80 °C for 7 h. The reaction mixture was concentrated and the resulting
residue was purified by preparative HPLC (TSK gel ODS-80Ts, Tosoh
Corp., H2O/MeCNꢁ9/1) to give the free base of 11d as an amorphous solid.
This amorphous solid was dissolved in a solution of 1 N hydrogen chloride
(10 ml) and the mixture was stored at room temperature for 10 min. The
mixture was concentrated to give 11d (228 mg, 0.366 mmol, 81%) as an
9c: 1H-NMR (DMSO-d6) d: 1.72—1.87 (2H, m), 1.95—2.11 (2H, m),

400
Vol. 55, No. 3
amorphous solid.
(ethanesulfonyl)indoline Dihydrochloride (21) 4-[1-(t-Butoxycarbonyl)-
Similarly, other bisamidine derivatives 11e, 11f and 11i were prepared.
piperidin-4-yloxy]-2-(7-cyanonaphthalen-2-yl)-1-(ethanesulfonyl)indoline
t-Butyl 4-(3-Nitrophenoxy)piperidine-1-carboxylate (13) Diisopropyl 19 was converted to 21 by the same procedure as that for 10d. Compound 21
azodicarboxylate (DIAD) (8.50 ml, 43.2 mmol) was added to a solution of 3-
nitrophenol 12 (5.00 g, 35.9 mmol), 1-(t-butoxycarbonyl)-4-hydroxypiperi-
dine 7 (8.68 g, 43.1 mmol) and PPh3 (11.30 g, 43.1 mmol) in CH2Cl2
(100 ml), and the resulting mixture was stirred at room temperature for 3 h.
was obtained (51%, 3 steps) as a pale yellow amorphous solid.
Similarly, the 6-substituted indoline derivative 22 was prepared.
2-(7-Cyanonaphthalen-2-yl)-1-(ethanesulfonyl)-5-{(trifluoromethane-
sulfonyl)oxy}indoline (24) To a solution of 2-(7-cyanonaphthalen-2-yl)-1-
The reaction mixture was concentrated and the resulting residue was chro- (ethanesulfonyl)-5-hydroxyindoline 23 (1.00 g, 2.64 mmol) in pyridine (10
matographed on a silica gel column (hexane/EtOAcꢁ17/3) to give 13 ml) was added trifluoromethanesulfonic anhydride (0.490 ml, 2.91 mmol),
(9.72 g, 30.1 mmol, 84%) as a pale yellow oil. 1H-NMR (CDCl3) d: 1.48 and the mixture was stirred at 0 °C for 5 min and room temperature for 1 h.
(9H, s), 1.71—1.85 (2H, m), 1.89—2.03 (2H, m), 3.32—3.44 (2H, m), The resulting mixture was poured into H2O and extracted with EtOAc. The
3.65—3.76 (2H, m), 4.53—4.62 (1H, m), 7.23 (1H, dd, Jꢁ2.5, 8.0 Hz), 7.43
(1H, t, Jꢁ8.0 Hz), 7.74 (1H, t, Jꢁ2.5 Hz), 7.83 (1H, dd, Jꢁ2.5, 8.0 Hz).
organic layer was washed with H2O, 1 N HCl and brine. The organic layer
was dried and concentrated. The resulting residue was chromatographed
t-Butyl 4-[3-Nitro-2-(trimethylsilylmethyl)phenoxy]piperidine-1-car- on a silica gel column (hexane/EtOAcꢁ4/1—1/1) to give 24 (1.27 g,
boxylate (14) and t-Butyl 4-[3-Nitro-4-(trimethylsilylmethyl)phenoxy]- 2.49 mmol, 94%) as a yellow solid. 1H-NMR (CDCl3) d: 1.31 (3H, t,
piperidine-1-carboxylate (15) To a solution of t-butyl 4-(3-nitrophe- Jꢁ7.5 Hz), 2.88—3.00 (2H, m), 3.11 (1H, dd, Jꢁ3.5, 17.0 Hz), 3.91 (1H,
noxy)piperidine-1-carboxylate 13 (8.42 g, 26.1 mmol) in THF (40 ml) was
slowly added (trimethylsilylmethyl)magnesium chloride (1.0 M in Et2O,
30.0 ml, 30.0 mmol) and the mixture was stirred at ꢂ30 °C for 0.5 h. Then a
dd, Jꢁ11.0, 17.0 Hz), 5.71 (1H, dd, Jꢁ3.5, 11.0 Hz), 7.13—7.21 (2H, m),
7.51—7.65 (3H, m), 7.84—7.93 (3H, m), 8.23 (1H, br s).
5-{[1-(t-Butoxycarbonyl)piperidin-4-yl]methyl}-2-(7-cyanonaph-
solution of DDQ (6.20 g, 27.3 mmol) in THF (80 ml) was added slowly and thalen-2-yl)-1-(ethanesulfonyl)indoline (26) To a solution of 9-borabicy-
the mixture was stirred at ꢂ30 °C for 2 h. The reaction mixture was concen- clo[3.3.1]nonane (BBN) (0.4 M in THF, 5.4 ml, 2.2 mmol) was added 1-(t-bu-
trated and the resulting residue was suspended in EtOAc. The mixture toxycarbonyl)-4-methylenepiperidine 25 (400 mg, 2.03 mmol) and the mix-
was filtrated through a silica gel column and the filtrate was concentrated. ture was refluxed for 7 h. The resulting mixture was allowed to stand at room
The resulting residue was chromatographed on
(hexane/EtOAcꢁ19/1—17/3) to give 14 (1.81 g, 4.43 mmol, 17%) as a yel- 5-{(trifluoromethanesulfonyl)oxy}indoline (739 mg, 1.45 mmol) in DMF
low oil and 15 (1.93 g, 4.72 mmol, 18%) as a yellow oil, respectively. (6 ml), PdCl2(dppf)·CH2Cl2 (118 mg, 0.144 mmol) and K2CO3 (301 mg,
a silica gel column temperature overnight and 2-(7-cyanonaphthalen-2-yl)-1-(ethanesulfonyl)-
1
14: H-NMR (CDCl3) d: 0.00 (9H, s), 1.48 (9H, s), 1.71—1.82 (2H, m), 2.18 mmol) in H2O (10 ml) were added. The mixture was stirred at 80 °C
1.93—2.02 (2H, m), 2.48 (2H, s), 3.25—3.35 (2H, m), 3.70—3.81 (2H, m),
4.48—4.57 (1H, m), 7.00 (1H, d, Jꢁ8.0 Hz), 7.12 (1H, t, Jꢁ8.0 Hz), 7.43
for 5 h and the resulting mixture was poured into 1 N NaOH and extracted
with EtOAc. The organic layer was washed with H2O and brine. The organic
layer was dried and concentrated. The resulting residue was chromato-
(1H, d, Jꢁ8.0 Hz).
1
15: H-NMR (CDCl3) d: 0.00 (9H, s), 1.47 (9H, s), 1.68—1.82 (2H, m), graphed on a silica gel column (hexane/EtOAcꢁ9/1—1/1) to give 26
1
1.88—1.98 (2H, m), 2.49 (2H, s), 3.30—3.39 (2H, m), 3.65—3.76 (2H, m), (283 mg, 0.506 mmol, 35%) as a colorless oil. H-NMR (CDCl3) d: 1.08—
4.42—4.51 (1H, m), 7.01—7.06 (2H, m), 7.48 (1H, d, Jꢁ2.5 Hz).
1.75 (5H, m), 1.32 (3H, t, Jꢁ7.5 Hz), 1.45 (9H, s), 2.47—3.18 (9H, m),
t-Butyl 4-{3-Amino-2-[2-(7-cyanonaphthalen-2-yl)-2-hydroxyethyl]- 3.88 (1H, dd, Jꢁ10.5, 16.0 Hz), 5.64 (1H, dd, Jꢁ3.5, 10.5 Hz), 6.96—7.06
phenoxy}piperidine-1-carboxylate (17) To a solution of t-butyl 4-[3-
nitro-2-(trimethylsilylmethyl)phenoxy]piperidine-1-carboxylate 14 (1.81 g,
4.43 mmol) and 7-formylnaphthalene-2-carbonitrile 16 (1.04 g, 5.74 mmol)
(2H, m), 7.41 (1H, d, Jꢁ8.0 Hz), 7.56—7.62 (2H, m), 7.84—7.90 (3H, m),
8.20 (1H, br s).
5-{[1-(Acetimidoyl)piperidin-4-yl]methyl}-2-(7-amidinonaphthalen-2-
in THF (25 ml) was slowly added a solution of TBAF monohydrate (116 mg, yl)-1-(ethanesulfonyl)indoline Dihydrochloride (27) 5-{[1-(t-Butoxycar-
0.444 mmol) in THF (3 ml) and the mixture was stirred at ꢂ10 °C for 0.5 h.
bonyl)piperidin-4-yl]methyl}-2-(7-cyanonaphthalen-2-yl)-1-(ethanesul-
TBAF (75% in H2O, 772 mg, 2.21 mmol) was then added and the mixture
fonyl)indoline 26 was converted to 27 by the same procedure as for 10d.
was stirred at room temperature for 1 h. NH4Cl solution was added, and the Compound 27 was obtained (27%, 3 steps) as a pale brown amorphous
mixture was extracted with EtOAc. The organic layer was washed with solid.
brine, dried and concentrated. The resulting residue was chromatographed
t-Butyl 4-(4-Nitroanilyl)piperidine-1-carboxylate (30) A solution of t-
on a silica gel column (hexane/EtOAcꢁ4/1—1/1) to give t-butyl 4-{2-[2-(7- butyl 4-aminopiperidine-1-carboxylate 29 (10.0 g, 49.9 mmol) in DMA
cyanonaphthalen-2-yl)-2-hydroxyethyl]-3-nitrophenoxy}piperidine-1-car- (100 ml) was treated with NaH (2.18 g, 50.0 mmol, as a 55% w/w dispersion
boxylate (1.29 g, 2.49 mmol, 56%) as a yellow amorphous solid. 1H-NMR in mineral oil) under cooling conditions and the mixture was stirred at
(CDCl3) d: 1.49 (9H, s), 1.72—1.87 (2H, m), 1.96—2.09 (2H, m), 3.30— 0 °C for 15 min. Then a solution of 4-fluoro-1-nitrobenzene 28 (7.04 g,
3.44 (4H, m), 3.70—3.84 (2H, m), 4.58—4.67 (1H, m), 5.26 (1H, t, 49.9 mmol) in DMA (30 ml) was added and the mixture was stirred
Jꢁ6.0 Hz), 7.16 (1H, d, Jꢁ8.5 Hz), 7.38 (1H, t, Jꢁ8.5 Hz), 7.47 (1H, d, overnight at room temperature. H2O was added and the mixture was ex-
Jꢁ8.5 Hz), 7.61 (1H, dd, Jꢁ1.5, 8.0 Hz), 7.72 (1H, dd, Jꢁ1.5, 8.0 Hz),
tracted with EtOAc. The organic layer was washed with brine, dried and
7.90—7.95 (3H, m), 8.24 (1H, br s). To a solution of this amorphous solid concentrated. The resulting residue was chromatographed on a silica gel col-
(1.29 g, 2.49 mmol) in AcOH (15 ml) was added Sn powder (1.77 g, umn (hexane/EtOAcꢁ9/1—3/2) to give 30 (7.86 g, 26.7 mmol, 95%) as a
14.9 mmol) and the mixture was stirred at room temperature for 1 h. The re-
action mixture was filtered and the filtrate was concentrated. The resulting 2.10 (2H, m), 2.88—3.02 (2H, m), 3.46—3.60 (1H, m), 4.01—4.18 (2H, m),
yellow solid. 1H-NMR (CDCl3) d: 1.33—1.60 (2H, m), 1.47 (9H, s), 1.99—
residue was diluted with EtOAc and washed with NaHCO3 solution and
brine. The organic layer was dried and concentrated. The resulting residue
was chromatographed on a silica gel column (hexane/EtOAcꢁ4/1—1/1) to
6.53 (2H, d, Jꢁ9.0 Hz), 8.09 (2H, d, Jꢁ9.0 Hz).
t-Butyl 4-(N-Methyl-4-nitroanilyl)piperidine-1-carboxylate (31)
solution of t-butyl 4-(4-nitroanilyl)piperidine-1-carboxylate 30 (100 mg,
A
give 17 (936 mg, 1.92 mmol, 77%) as a pale yellow amorphous solid. 1H- 0.311 mmol) in DMF (3 ml) was treated with NaH (15.0 mg, 0.344 mmol, as
NMR (CDCl3) d: 1.49 (9H, s), 1.62—2.05 (4H, m), 2.94 (1H, dd, Jꢁ9.5, a 55% w/w dispersion in mineral oil) under cooling conditions and the mix-
14.0 Hz), 3.21 (1H, dd, Jꢁ2.5, 14.0 Hz), 3.28—3.45 (2H, m), 3.60—3.77 ture was stirred at room temperature for 15 min. Then MeI (0.020 ml,
(2H, m), 4.45—4.55 (1H, m), 5.17 (1H, dd, Jꢁ2.5, 9.5 Hz), 6.35—6.42 (2H, 0.32 mmol) was added and the mixture was stirred at room temperature for
m), 7.03 (1H, t, Jꢁ8.0 Hz), 7.61 (1H, dd, Jꢁ1.5, 8.5 Hz), 7.69 (1H, dd, 1 h. NH4Cl solution was added and the mixture was extracted with EtOAc.
Jꢁ1.5, 8.5 Hz), 7.88—7.94 (3H, m), 8.22 (1H, br s).
4-[1-(t-Butoxycarbonyl)piperidin-4-yloxy]-2-(7-cyanonaphthalen-2- The resulting residue was chromatographed on
yl)-1-(ethanesulfonyl)indoline (19) t-Butyl 4-{3-amino-2-[2-(7-cyano- (hexane/EtOAcꢁ9/1—7/3) to give 31 (96.6 mg, 0.288 mmol, 93%) as a yel-
naphthalen-2-yl)-2-hydroxyethyl]phenoxy}piperidine-1-carboxylate 17 was
The organic layer was washed with H2O and brine, dried and concentrated.
a
silica gel column
low solid. 1H-NMR (CDCl3) d: 1.49 (9H, s), 1.67—1.80 (4H, m), 2.76—
converted to 19 by the same procedure as that for 8d. Compound 19 was ob- 2.89 (2H, m), 2.91 (3H, s), 3.83—3.93 (1H, m), 4.21—4.37 (2H, m), 6.70
1
tained (79%, 2 steps) as a pale yellow amorphous solid. H-NMR (CDCl3) (2H, d, Jꢁ9.5 Hz), 8.13 (2H, d, Jꢁ9.5 Hz).
d: 1.32 (3H, t, Jꢁ7.0 Hz), 1.45 (9H, s), 1.64—1.81 (2H, m), 1.82—1.98
5-{N-[1-(t-Butoxycarbonyl)piperidin-4-yl]-N-methylamino}-2-(7-
(2H, m), 2.92—3.13 (3H, m), 3.27—3.43 (2H, m), 3.51—3.67 (2H, m), 3.76 cyanonaphthalen-2-yl)-1-(ethanesulfonyl)indoline (32) t-Butyl 4-(N-
(1H, dd, Jꢁ11.0, 17.0 Hz), 4.47—4.57 (1H, m), 5.66 (1H, dd, Jꢁ3.5,
11.0 Hz), 6.62 (1H, d, Jꢁ8.0 Hz), 7.12 (1H, d, Jꢁ8.0 Hz), 7.23 (1H, t,
Jꢁ8.0 Hz), 7.56—7.63 (2H, m), 7.84—7.92 (3H, m), 8.22 (1H, br s).
4-[1-(Acetimidoyl)piperidin-4-yloxy]-2-(7-amidinonaphthalen-2-yl)-1-
methyl-4-nitroanilyl)piperidine-1-carboxylate 31 was converted to 32 by the
same procedure as that for 19. Compound 32 was obtained (8%, 5 steps) as a
yellow amorphous solid. H-NMR (CDCl3) d: 1.33 (3H, t, Jꢁ7.5 Hz), 1.47
(9H, s), 1.55—1.75 (4H, m), 2.70—3.21 (5H, m), 2.74 (3H, s), 3.56—3.64
1

March 2007
401
until use. Plasma clotting times were measured by an automated blood coag-
ulation analyzer, COAGMASTER II (Sankyo, Japan), using PT reagent,
SIMPLASTIN EXCEL (Organon Teknika, NC, U.S.A.). Coagulation times
for each compound were compared with the control. In the control group,
distilled water instead of the test compound solution was added to plasma.
Each measurement was performed three times. The concentration required
to double the clotting time (CT2) was estimated by linear regression analysis
using two data points, the two mean values of the concentrations closest to
the predicted 2-fold PT on either side of the predicted 2-fold PT.
(1H, m), 3.86 (1H, dd, Jꢁ10.0, 16.5 Hz), 4.18—4.26 (2H, m), 5.60 (1H, dd,
Jꢁ2.5, 10.0 Hz), 6.65—6.75 (2H, m), 7.40 (1H, d, Jꢁ9.0 Hz), 7.56—7.62
(2H, m), 7.82—7.89 (3H, m), 8.20 (1H, br s).
5-{N-[1-(Acetimidoyl)piperidin-4-yl]-N-methylamino}-2-(7-amidino-
naphthalen-2-yl)-1-(ethanesulfonyl)indoline Trihydrochloride (33) 5-
{N-[1-(t-Butoxycarbonyl)piperidin-4-yl]-N-methylamino}-2-(7-cyanonaph-
thalen-2-yl)-1-(ethanesulfonyl)indoline 32 was converted to 33 by the same
procedure as that for 10d. Compound 33 was obtained (12%, 3 steps) as a
pale brown amorphous solid.
Ex Vivo Studies: Compounds were dissolved in distilled water and orally
administered to hamsters (Japan SLC), marmosets (CLEA Japan) and
cynomolgus monkeys (CLEA Japan) in a volume of 1 ml/kg. One to six
hours after the administration, blood was collected into a plastic syringe
containing 3.8% sodium citrate. Plasma was prepared and coagulation times
were measured using a coagulometer, KC-10A micro (Heinrich Amelung
GmbH), using PT reagent, Thromboplastin C plus (Dade Behring Marburg
GmbH). The CT2 values were estimated as described above.
(S)-7-{1-[(S)-a-(Acetoxyphenyl)acetoxy]-2-[5-(methoxymethoxy)-2-ni-
trophenyl]ethyl}naphthalene-2-carbonitrile ((S)-34) To a solution of 7-
{1-hydroxy-2-[5-(methoxymethoxy)-2-nitrophenyl]ethyl}naphthalene-2-car-
bonitrile 2 (22.00 g, 58.14 mmol) in CH2Cl2 (250 ml) were added (S)-acetyl-
mandel chloride (14.8 g, 69.6 mmol) in CH2Cl2 (20 ml) and pyridine (9.19 g,
116 mmol) at 0 °C, and the mixture was stirred at room temperature for 2 h.
The reaction mixture was concentrated, and the resulting residue was dis-
solved in EtOAc. The resulting mixture was washed with H2O and brine,
dried and concentrated. The resulting residue was crystallized from EtOAc
and Et2O (1/20) to give (S)-32 (10.46 g, 18.86 mmol, 32%) as colorless crys-
Acknowledgments We would like to thank Ms. Naoko Suzuki and Ms.
Yumiko Fujisawa for their expert technical assistance, and Dr. Ken-ichi
Otsuguro for his helpful discussions.
1
tals. H-NMR (CDCl3) d: 2.13 (3H, s), 3.32 (1H, dd, Jꢁ9.5, 14.0 Hz), 3.49
(3H, m), 3.61 (1H, dd, Jꢁ3.0, 14.0 Hz), 5.26 (2H, s), 5.98 (1H, s), 6.22 (1H,
dd, Jꢁ3.0, 9.5 Hz), 6.99—7.09 (2H, m), 7.17 (1H, br s), 7.36—7.60 (7H, m),
7.75 (1H, d, Jꢁ8.5 Hz), 7.80—7.88 (2H, m), 8.09 (1H, d, Jꢁ9.0 Hz). [a]D
ꢃ73.6° (cꢁ1.00, CHCl3).
References and Notes
1) Present address: Business Operations Administration Department,
Sankyo Co., Ltd.
Additional Synthesis of (S)-7-{1-[(S)-a-(Acetoxyphenyl)acetoxy]-2-[5-
(methoxymethoxy)-2-nitrophenyl]ethyl}naphthalene-2-carbonitrile ((S)-
32) The filtrate obtained above was concentrated and the resulting residue
was dissolved in MeOH (200 ml). To the solution was added K2CO3 (1.30 g,
9.41 mmol), and the resulting mixture was stirred at 80 °C for 15 min. The
mixture was concentrated and the resulting residue was dissolved in EtOAc.
The resulting mixture was washed with H2O and brine, dried and concen-
trated. The resulting residue was chromatographed on a silica gel column
(hexane/EtOAcꢁ1/1) to give a mixture of (S)-2 and (R)-2 ((R)-2>(S)-2,
13.12 g) as a colorless solid. To a solution of this solid (13.12 g, 34.67
mmol), (S)-acetylmandelic acid (10.10 g, 52.10 mmol) and PPh3 (13.60 g,
51.85 mmol) in CH2Cl2 (200 ml) was added DEAD (40% in toluene,
22.65 g, 52.02 mmol) at 0 °C. The resulting mixture was stirred at the
same temperature for 0.5 h and at room temperature for 3 h. The reaction
mixture was concentrated, and the resulting residue was chromatographed
on a silica gel column (hexane/EtOAcꢁ1/1) to give a diastereomixture of
mandelate 32 (22.58 g) as an amorphous solid. The amorphous solid
(22.58 g) was crystallized from Et2O to give (S)-32 (10.11 g, 18.23 mmol,
45%) as crystals. [a]D ꢃ74.6° (cꢁ1.00, CHCl3).
(S)-7-{2-[2-Amino-5-(methoxymethoxy)phenyl]-1-hydroxyethyl}naph-
thalene-2-carbonitrile ((S)-3) To a suspension of (S)-7-{1-[(S)-a-(ace-
toxyphenyl)acetoxy]-2-[5-(methoxymethoxy)-2-nitrophenyl]ethyl}naphtha-
lene-2-carbonitrile (S)-32 (23.00 g, 41.48 mmol) in MeOH (200 ml) was
added K2CO3 (2.00 g, 14.5 mmol), and the resulting mixture was stirred at
60 °C for 20 min. The mixture was diluted with EtOAc and the resulting
mixture was washed with H2O, dried and concentrated. The resulting residue
was chromatographed on a silica gel column (hexane/EtOAcꢁ1/1) to give
(S)-2 (15.62 g, 41.28 mmol) as a colorless solid. A solution of (S)-2 (15.00 g,
39.64 mmol) in THF (30 ml) and EtOH (200 ml) was hydrogenated over
10% Pd–C (2.00 g) at room temperature for 6 h with stirring. The catalyst
was filtered away, and the filtrate was concentrated. The resulting residue
was chromatographed on a silica gel column (hexane/EtOAcꢁ1/2) to give
(S)-3 (10.01 g, 28.73 mmol, 72%) as an oil. [a]D ꢂ11.3° (cꢁ1.00, CHCl3).
Optically active bisamidine derivatives ((R)-10d and (R)-11d) were pre-
pared in a manner similar to their racemates from (S)-2.
2) Harder S., Thurmann P., Clin. Pharmacokinet., 30, 416—444 (1996).
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Synth. Commum., 26, 4351—4367 (1996).
12) The stereochemistry of two regioisomers (14, 15) was confirmed by
their coupling constants of 1H-NMR spectra.
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3694—3696 (1986).
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(R)-10d: [a]D ꢂ47° (cꢁ0.35, MeOH), >99% ee.
(R)-11d: [a]D ꢂ52° (cꢁ0.37, MeOH), >99% ee.
19) At first, we tried to adopt aryl amino reaction against trifluoromethane-
sulfonate 24 to prepare methylaminoindoline derivative 33.24,25) In
spite of many efforts, the reaction was result in recovery of compound
24.
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(2004).
21) In the previous report, (S)-3 was obtained from separation of (RS)-3 by
preparative chiral HPLC. (S)-3 was converted to compound (R)-35,
then we determined the stereochemistry of (R)-35 and (S)-3 (the start-
ing material of (R)-35) by X-ray crystallographic analysis of (R)-35.
This time, each retention time of (S)-3 and (R)-3 was already in hand,
so we determined their stereochemistry by comparison of its retention
time.
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-
vice, CA, U.S.A.). Reaction mixtures (90 ml) were prepared in 96-well plates
containing human FXa (0.5IU, Enzyme Research Laboratories, 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 concentration required
to inhibit enzyme activity by 50% (IC50) was estimated from the concentra-
tion-response curves.
Coagulation Assay. In Vitro Studies: Citrated blood samples were col-
lected from healthy male volunteers or male hamsters (Japan SLC). Plasma
was prepared by centrifugation at 2000ꢄg for 10 min and stored at ꢂ20 °C

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of (RS)-1 and 11d. The plasma concentration of (RS)-1 at the time of
mice’s death (3—5 min) was 9.5 mg/ml, while that of 11d at the time
of Cmax (10 min) was 7.0 mg/ml. As a result, no significant difference
was observed in plasma concentration of both compounds. This result
indicates that the difference of toxicity between (RS)-1 and 11d isn’t
induced by the plasma concentration but these compounds themselves
(unpublished data).
24) Guram A. F., Rennels R. A., Buchwald S. L., Angew. Chem. Int. Ed.
Engl., 1995, 1348—1350 (1995).
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22) Oliver J. E., DeMilo A. B., Synthesis, 1975, 321—322 (1975).
23) In acute toxicity test in mice, we compared the plasma concentration