Novel acetylcholinesterase inhibitor as increasing agent on rhythmic bladder contractions: SAR of 8-{3-[1-(3-fluorobenzyl)piperidin-4-yl]propanoyl}- 1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-one (TAK-802) and related compounds

Article abstract of DOI:10.1016/j.bmc.2005.01.022

As part of an on-going investigation to develop an increasing agent on rhythmic bladder contractions, 1-aryl-3-(1-benzylpiperidin-4-yl)propanones were synthesized and examined as noncarbamate acetylcholinesterase (AChE) inhibitors. Among compounds with va

Full text of DOI:10.1016/j.bmc.2005.01.022

Bioorganic & Medicinal Chemistry 13 (2005) 1901–1911
Novel acetylcholinesterase inhibitor as increasing agent on
rhythmic bladder contractions: SAR of
8-{3-[1-(3-fluorobenzyl)piperidin-4-yl]propanoyl}-1,2,5,6-
tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-one (TAK-802)
and related compounds
Yuji Ishichi,a Mitsuru Sasaki,a Masaki Setoh,a Tetsuya Tsukamoto,a Seiji Miwatashi,a
Hiroshi Nagabukuro,b Satoshi Okanishi,b Shigemitsu Imai,b Reiko Saikawa,b
Takayuki Doib and Yuji Ishiharaa,*
aMedicinal Chemistry Research Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Ltd,
2-17-85, Jusohonmachi, Yodogawa-ku, Osaka 532-8686, Japan
bPharmaceutical Research Laboratories I, Pharmaceutical Research Division, Takeda Pharmaceutical Company Ltd,
2-17-85, Jusohonmachi, Yodogawa-ku, Osaka 532-8686, Japan
Received 8 November 2004; revised 14 January 2005; accepted 14 January 2005
Abstract—As part of an on-going investigation to develop an increasing agent on rhythmic bladder contractions, 1-aryl-3-(1-benz-
ylpiperidin-4-yl)propanones were synthesized and examined as noncarbamate acetylcholinesterase (AChE) inhibitors. Among com-
pounds with various aryl groups, 1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-one derivative 9c was found to possess a potent
AChE inhibition activity with an IC50 value of 1.3 nM. The compound 9c increased rhythmic bladder contractions in Guinea pigs
and rats without affecting the basal intravesical pressure, which suggests that 9c may be useful for the treatment of voiding dysfunc-
tion caused by detrusor underactivity.
ꢀ 2005 Elsevier Ltd. All rights reserved.
N
1. Introduction
.
HO2C
N
H
CO2H
Demographic changes resulting in a progressively aging
society have seen a growing incidence of lower urinary
tract symptoms (LUTS), and increased attention is
being paid to quality of life (QOL) maintenance of
LUTS patients. LUTS are classified into two categories:
storage dysfunction (including urinary frequency, noctu-
ria, and urinary incontinence) and voiding dysfunction
(characterized by difficulty in urination or urinary reten-
tion).1 Difficulty in urination frequently results in loss in
QOL, making voiding dysfunction a significant medical
target. One of the causes of the voiding dysfunction is
O
TAK-147
CH3
O
O
H3C
H3C
H3C
-
N
.
Cl
NH2
Bethanechol Chloride
CH3
N
O
CH3
N
O
-
O
N
CH3
.
2Br
O
N
CH3
Keywords: Acetylcholinesterase inhibitor; Pyrrolos[3,2,1-ij]quinolin-4-
one; Rhythmic bladder contraction; TAK-802.
Distigmine Bromide
*
Figure 1. Structures of TAK-147, bethanechol chloride, and distig-
mine bromide.
Corresponding author. Tel.: +81 6 6300 6413; fax: +81 6 6300
6306; e-mail: Ishihara_Yuji@takeda.co.jp
0968-0896/$ - see front matter ꢀ 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2005.01.022

1902
Y. Ishichi et al. / Bioorg. Med. Chem. 13 (2005) 1901–1911
impaired detrusor contractility known as detrusor
underactivity. The detrusor underactivity is associated
with aging, prostatic hypertrophy, diabetes, and multi-
ple sclerosis. The detrusor muscle is known to be under
the control of the parasympathetic nerve, for which one
of the major transmitters is acetylcholine (ACh). At
present, some cholinergic agents such as bethanechol2
or distigmine3 are clinically used to treat patients with
detrusor underactivity in order to potentiate bladder
contractions. Bethanecol, an ACh analogue that under-
goes only slight hydrolysis by AChE, is considered to
induce bladder contractions (Fig. 1) by acting on musca-
rinic ACh receptors of the detrusor muscle. However,
continuous cholinergic stimulation of the detrusor mus-
cle is considered to cause reduction in bladder compli-
ance. Distigmine, a long acting carbamate AChE
inhibitor, does not have sufficient therapeutic effect4 pre-
sumably owing to increasing urethral resistance. This
undesirable action is supposed to be a result of the direct
agonist effect of carbamate agents on nicotinic ACh
receptors in the urethra.5 We therefore hypothesized
that an AChE inhibitor, which does not possess a carba-
mate structure could avoid direct activation of nicotinic
ACh receptors and improve bladder voiding function
more effectively than carbamates. As a novel class of
AChE inhibitor bearing 1-aryl-3-(1-benzylpiperidin-4-
yl)propanone structure, one of us (Y.I.) and his co-
workers have previously reported a SAR of TAK-147
(Fig. 1) and its preclinical potential for the treatment
of Alzheimerꢀs disease.6 In this study, preliminary exam-
ination revealed that TAK-147 increased rhythmic blad-
der contractions in Guinea pigs. Thus, taking TAK-147
as a lead compound, we planned to synthesize and eval-
uate 1-aryl-3-(1-benzylpiperidin-4-yl)propanones as
increasing agents on rhythmic bladder contractions.
On the optimization, we focused a modification of 1-aryl
group, which is supposed to locate at the entrance of the
enzymeꢀs active site and is thought to be tolerable for
modification.6c Among various aryl groups, we found
1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-one is
preferable for the potent AChE inhibition. In this
report, we describe the synthesis and SAR of 8-{3-[1-
(3-fluorobenzyl)piperidin-4-yl]propanoyl}-1,2,5,6-tetra-
hydro-4H-pyrrolo[3,2,1-ij]quinolin-4-one 9c and related
compounds 1–11.
2. Chemistry
Compounds 1–4 were synthesized according to our pre-
vious report.6b The syntheses of bicyclic compounds 5–7
is outlined in Scheme 1. We have reported that Friedel–
Crafts acylation of NH-protected 2-benzazepine 14a
and 1,4-benzoxazepine 14c proceeded in a highly regio-
selective manner to give 8-acyl-2-benzazepine and 7-
acyl-1,4-benzoxazepine, respectively.7a For the NH-pro-
tected 3-benzazepine, only 7-acylation products have
been reported.7b We applied these findings to the synthe-
sis of 2-benzazepine 5, 3-benzazepine 6, and 1,4-benz-
oxazepine derivative 7. In the previous procedure of
the synthesis of 2-benzazepine derivative 5, methoxycar-
bonyl group was used as a NH-protecting group of
piperidine nitrogen.7a For the ease of deprotection, we
have chosen a para-nitrobenzyloxycarbonyl as the pro-
tecting group. 4-Piperidinepropanoic acid 12 was
protected with a para-nitrobenzyloxycarbonyl group,8
which is stable to Friedel–Crafts acylation conditions,
and the resulting carboxylic acid was converted to acid
chloride 13 by treating with thionyl chloride. Friedel–
Crafts acylation of appropriately NH-protected bicyclic
compounds 14a–c9 with acid chloride 13 were carried
out in the presence of 3 equiv of aluminum chloride to
give 15a–c. After selective deprotection of the para-
nitrobenzyloxycarbonyl group of 15a–c, 16a–c were
alkylated with benzyl bromide to afford 17a–c, which
were then deprotected under acidic or basic hydrolysis
conditions to give 5–7.
The syntheses of tricyclic compounds 8, 9a–s, 10, and 11
is shown in Scheme 2. The tricyclic heterocycles 19a–d
were synthesized according to literature methods.10 Fri-
edel–Crafts acylation of 3-(1-acetylpiperidin-4-yl)propa-
noyl chloride (18)11 with 19a–d afforded 20a–d as single
regioisomers. After deprotection of the acetyl group,
21a–d were alkylated with substituted benzyl halides to
give 8, 9a–s, 10, and 11.
n
R
N
O
O
O
n
NO2
R
NO2
X
m
HO
Cl
N
a, b
14a—c
NH
N
O
N
O
X
m
c
.
HCl
O
O
12
13
15a—c
d
O
O
O
n
n
n
R
R
e
f (for 17a,c), h
g (for 17b), h
HN
N
N
N
N
NH
X
X
X
m
m
m
.
2HCl
5-7
17a—c
16a—c
2-Benzazepines: 5, 14a, 15a, 16a, 17a; X=-(CH2)-, m=2, n=1, R=Ac
3-Benzazepines: 6, 14b, 15b, 16b, 17b; X=-(CH2)-, m=1, n=2, R=COCF3
1,4-Benzoxazepines: 7, 14c, 15c, 16c, 17c; X=O, m=2, n=1, R=CHO
Scheme 1. Reagents and conditions: (a) PNB-OCOCl, THF, H2O, KOH; (b) SOCl2; (c) 14a–c, AlCl3, CH2Cl2; (d) H2, Pd–C, EtOH–THF;
(e) PhCH2Br, K2CO3, CH3CN; (f) concd HCl,120 ꢁC; (g) K2CO3, H2O, MeOH; (h) HCl.

Y. Ishichi et al. / Bioorg. Med. Chem. 13 (2005) 1901–1911
1903
m
O
O
O
O
N
Cl
19a–d
m
m
n
N
b
N
NH
Ac
O
N
Ac
O
N
a
n
n
18
20a–d
21a–d
c, d
O
19a, 20a, 21a, 8 : m=0, n=2
19b, 20b, 21b, 9a–s : m=1, n=1
19c, 20c, 21c, 10 : m=1, n=2
19d, 20d, 21d, 11 : m=2, n=1
m
Y
N
O
N
.
HCl
n
8,9a–s,10,11
Scheme 2. Reagents and conditions: (a) 19a–d, AlCl3, CH2Cl2; (b) concd HCl, 140 ꢁC; (c) substituted benzyl halides, K2CO3, CH3CN; (d) HCl.
3. Results and discussion
3.1. AChE inhibition activity
Table 1. AChE inhibitory activity of compounds with various hetero-
cyclic frameworks 1–11
O
The AChE inhibition activity was measured by Ellmanꢀs
method12 using human-erythrocyte-derived AChE. Dis-
tigmine was tested as a reference compound and the IC50
value was measured as 380 nM. The effect of 1-aryl
groups was evaluated and the results are shown in Table
1. All compounds exhibited potent activities with IC50ꢀs
in the 1–200 nM range. In general, compounds bearing
tricyclic groups showed 10 to 100 times more potent
than those with bicyclic groups. Among compounds 1–
4 bearing bicyclic aromatic amines, the activity de-
creased slightly with increasing size of the heterocyclic
ring. With regard to the attachment position of 3-(1-
benzylpiperidin-4-yl)propanoyl group, 6-position was
found to be better than the 7-position (cf. 2 vs 3). These
results correspond well with our previous data using rat
cerebral cortex as the enzyme source.6b The AChE inhi-
bition activities of 2-benzazepine 5, 3-benzazepine 6, and
oxazepine 7 were slightly potent as compared to those of
compounds 1–4. Compounds bearing tricyclic hetero-
cycles (8, 9a, 10, and 11) exhibited potent activity with
IC50 values in the range of 1.3–16 nM, and the activity
again tended to decrease slightly with increasing size
of the heterocyclic ring. Among various heterocyclic
Het
N
1—11
Compd
Het
Salt
hAChE inhibition
IC50
(nM)a
95% Clb
1
Fumarate
2HCl
53
64
(50–57)
N
H
2
(60–70)
N
H
3
Fumarate 166
Fumarate 193
(153–180)
(178–210)
N
H
4 (TAK-147)
N
H
5
6
7
2HCl
2HCl
2HCl
23
25
40
(21–24)
(23–27)
(38–42)
HN
HN
O
frameworks,
1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]
HN
quinolin-4-one derivative 9a possessed the most potent
activity. Thus, the effect of substituents (Y) on benzyl-
amino moiety of pyrrolo[3,2,1-ij]quinoline derivatives 9
was evaluated and the results are shown in Table 2.
Among substituents, fluoro, chloro, and hydroxy groups
retained the activity. The order of IC50 potency on sub-
stitution position was 3-, 2- > 4-, except for hydroxy
series 9k–m. Compound 9m (Y = 4-OH) exhibited
remarkably potent enzyme inhibition with an IC50 value
of 0.49 nM.
8
HCl
HCl
3.6 (3.3–3.9)
1.3 (1.0–1.7)
N
O
O
9a
N
10
HCl
HCl
9.8 (8.7–11)
O
N
11
16
380
(14–19)
N
3.2. Effect on rhythmic bladder contractions in Guinea
pigs and rats
O
Distigminec
(366–394)
a The IC50 value is the concentration required to inhibit control enzyme
activity by 50%. These values were calculated from the results of two
experiments conduced in duplicate. All compounds were dissolved in
distilled water.
b 95% confidence interval for each IC50 value.
c Distigmine bromide.
Selected compounds with potent AChE inhibition activ-
ity were examined for their effect on rhythmic bladder
contractions. In vivo efficacy was evaluated by measur-
ing distention-induced rhythmic bladder contractions
in Guinea pigs and rats. Figure 2 shows the intravesical

1904
Y. Ishichi et al. / Bioorg. Med. Chem. 13 (2005) 1901–1911
Table 2. The effect of substituents in 8-[3-(1-benzylpiperidin-4-yl)pro-
panoyl]-1,2,5,6-tetrahydro-4H-pyrrolo[3, 2,1-ij]quinolin-4-ones 9a–s
Table 3. AUC200 value and bioavailability of selected compounds
Compd
hAChE
inhibition
AUC200a
BAd,f
O
IC50
(nM)
Guinea pigs
(lg/kg, iv)b
Rats
Rats
(lg/kg, id)d,e (%)
Y
N
O
N
4 (TAK-147) 193
660
195
9a—s
5
23
25
Compda
Y
hAChE inhibition
6
560
IC50 (nM)b
95% Clc
8
3.6
9.8
16
5.4
10
11
9a
9b
9c
87
11.6
9a
9b
9c
9d
9e
9f
H
2-F
1.3
2.5
1.3
4.6
5.1
4.9
153
64
(1.0–1.7)
(2.3–2.8)
(1.2–1.5)
(4.1–5.3)
(4.6–5.6)
(4.2–5.6)
(143–163)
(61–68)
1.3
2.5
1.3
3.0
55
22
16
33
3-F
4-F
15
0.769
(0.075–1.877)c
2-Cl
3-Cl
9f
9k
4.9
1.1
8.7
0.49
5.0
1.0
9g
9h
9i
4-Cl
122
7.3
2-OMe
3-OMe
4-OMe
2-OH
3-OH
4-OH
2-NO2
3-NO2
4-NO2
2-CN
3-CN
4-CN
91
9m
Distigmineg
27
76
125
345
1.1
8.7
0.49
90
(116–135)
(321–371)
(0.97–1.2)
(7.9–9.6)
(0.45–0.54)
(83–98)
9j
380
21.1
(6.5–39.4)c
9k
91
9m
9n
9o
9p
9q
9r
9s
a Dose necessary to double the area under the curve (AUC) of the
vesical contraction. All compounds were dissolved in distilled water.
b Values are an average of 5–8 independent experiments.
c 95% Confidence interval for AUC200 value (iv). In the blanks, 95%
confidence levels could not be calculated.
d Compounds that exhibited potent AUC200 value in Guinea pigs were
examined.
e An average of 7–10 independent experiments.
f Preliminary pharmacokinetic data.
g Distigmine bromide.
2.9
43
(2.7–3.2)
(40–47)
(51–58)
55
6.8
32
(6.4–7.2)
(30–34)
(366–394)
Distigminec
380
a All compounds were tested as their HCl salts except distigmine.
b,c See corresponding footnotes of Table 1.
9k. AUC200 efficacy (id) of 9k was weak compared to
that of the iv administration, suggesting that 9k had
some pharmacokinetic deficiencies such as permeability
or metabolic stability. Preliminary pharmacokinetic
studies were conducted for compounds 9a, 9c, and 9k.
The bioavailability (BA) of 9k in rats was lower than
those of 9a and 9c (7.3% for 9k vs 16% for 9a, 33%
for 9c). In this intraduodenal study, 9c exhibited the
most potent increasing effect with an AUC200 value of
22 lg/kg, id. Based on these results, 9c was selected as
a candidate for further evaluation. Distigmine was also
tested in the rhythmic bladder contraction study, and
showed a modest AUC200 value of 21.1 lg/kg, iv, which
is better than was expected from its weak AChE inhibi-
tion activity (IC50 = 380 nM).15 However, it was re-
ported that distigmine heightened the risk of urinary
retention. Distigmine is presumed to increase intraure-
pressure (cystometrogram) before and after administr-
ation of 9c. Intravenous (iv) administration of 9c in-
creased bladder contractions mainly by prolonging the
duration of the contractions, and was evaluated using
the AUC200 value, which is the dose of compound nec-
essary to double the area under the curve (AUC) of the
vesical contraction.13 The AUC200 value of selected
compounds in Guinea pigs are shown in Table 3.
AUC200 efficacies in Guinea pigs (iv) were approxi-
mately parallel to the corresponding AChE inhibition
activity. Although the reason is not clear, 4-hydroxy
derivative 9m exhibited significantly low AUC200 effi-
cacy compared with its AChE IC50 value. Compounds
(9a, 9c, and 9k), which showed excellent iv AUC200
values, were evaluated for their efficacies in rats after
intraduodenal (id) administration.14 The values were
comparable to those of the iv examination except for
Compound 9c 0.01mg/kg, i.v.
10mmHg
5min
Time
Figure 2. Cystometrogram of anesthetized Guinea pig and the effect of 9c.

Y. Ishichi et al. / Bioorg. Med. Chem. 13 (2005) 1901–1911
1905
thral pressure owing to its excitation effect on nicotinic
receptors. We have previously studied the muscarinic
and nicotinic effects of 9c and distigmine,16 and the nico-
tinic effect of 9c was found to be about 1/3 of distigmine
by relative efficacy. Furthermore, distigmine inhibited
butyrylcholinesterase (BChE) activity with the IC50
value of 537 nM while that of 9c was >10,000 nM, sug-
gesting that 9c is more selective for parasympathetic ner-
vous.16 Thus, 9c is more effective than distigmine for its
more potent AUC200 value, lower nicotinic effect, and
high selectivity against BChE. On the other hand,
bethanechol, another agent for increasing bladder con-
tractions, was concerned about its continuous stimula-
tion of parasympathetic nervous system. And in our
rhythmic bladder contraction study, bethanechol had in-
creased basal intravesical pressure and diminished max-
imum intravesical pressure, indicating lowering bladder
compliance.16 Compound 9c increased bladder contrac-
tions only while the micturition reflex was evoked, and
did not affect the basal intravesical pressure. Thus, 9c
is considered to be more effective in the treatment of
voiding dysfunction caused by detrusor underactivity.
length 254 nm). Abbreviations for solvents are the fol-
lowing: Et2O, diethyl ether; EtOH, ethanol; EtOAc,
ethyl acetate; Hex, hexane; IPE, diisopropyl ether;
MeOH, methanol; THF, tetrahydrofuran.
5.1.1. Compounds 1–4 were prepared according to our
previous report.6b
5.1.2. 4-Nitrobenzyl 4-(3-chloro-3-oxopropyl)piperidine-
1-carboxylate (13). A solution of 4-nitrobenzyl chloro-
formate (16.7 g, 77.5 mmol) in THF (50 mL) was added
dropwise to a mixture of 3-piperidin-4-yl-propanoic acid
hydrochloride (12)11 (15.0 g, 44.3 mmol), aqueous KOH
solution (8.70 g, 155 mmol in H2O 100 mL), and THF
(50 mL) at 0 ꢁC. The mixture was stirred at room tem-
perature for 12 h. The mixture was concentrated in
vacuo, and acidified using 1 N HCl. The mixture was
extracted with EtOAc (2 times), dried over MgSO4,
and concentrated to give a colorless oil. The oil was
crystallized from Et2O–IPE to afford 3-(1-{[(4-nitrobenz-
yl)oxy]carbonyl}piperidin-4-yl)propanoic acid as color-
less crystals (17.9 g, 69%). Mp 99–100 ꢁC (Et2O–IPE).
1
IR (KBr) 2932, 1695, 1520, 1348, 852 cmÀ1. H NMR
(300 MHz, CDCl3) d 1.05–1.25 (m, 2H), 1.40–1.60 (m,
1H), 1.62 (q, J = 7.2 Hz, 2H), 1.65–1.80 (m, 2H), 2.40
(t, J = 7.2 Hz, 2H), 2.65–2.95 (m, 2H), 4.05–4.30 (m,
2H), 5.22 (s, 2H), 7.51 (d, J = 6.9 Hz, 2H), 8.00–10.00
(br, 1H), 8.22 (d, J = 6.9 Hz, 2H). Anal. Calcd for
C16H20N2O6: C, 57.14; H, 5.99; N, 8.33. Found: C,
57.08; H, 5.89; N, 8.39.
4. Conclusion
We have synthesized a series of novel noncarbamate
acetylcholinesterase inhibitors to identify improved
agents for the treatment of voiding dysfunction. Among
these compounds, 1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-
ij]quinolin-4-one derivative 9c exhibited potent AChE
inhibition activity with an IC50 value of 1.3 nM. Com-
pound 9c displayed an increasing effect on bladder con-
tractions with excellent efficacy, showing AUC200
values of 0.769 lg/kg, iv in Guinea pigs and 22 lg/kg,
id in rats. Furthermore, the nicotinic effect of 9c has
been shown to be about a third of that of carbamate
acetylcholinesterase inhibitor distigmine. Therefore,
compound 9c is expected to be an effective agent for
the treatment of voiding dysfunction caused by detrusor
underactivity, and clinical development of 9c as the free
base (TAK-802) is currently underway.
The 3-(1-[(4-nitrobenzyl)oxy]carbonylpiperidin-4-yl)pro-
panoic acid (8.00 g, 23.8 mmol) was added portionwise
to thionyl chloride (20 mL) at 0 ꢁC with stirring. The
mixture was stirred at room temperature for 1 h. The
thionyl chloride was removed in vacuo, and the residue
was crystallized from Et2O to afford 13 as colorless crys-
tals (7.00 g, 83%). Mp 64–65 ꢁC (Et2O). IR (KBr) 2936,
1799, 1699, 1607, 1522, 1346, 853 cmÀ1 1H NMR
.
(300 MHz, CDCl3) d 1.05–1.25 (m, 2H), 1.40–1.90 (m,
5H), 2.65–2.90 (m, 2H), 2.94 (t, J = 7.5 Hz, 2H), 4.10–
4.30 (m, 2H), 5.22 (s, 2H), 7.51 (d, J = 8.1 Hz, 2H),
8.22 (d, J = 8.1 Hz, 2H).
5.1.3.
4-Nitrobenzyl
4-{3-oxo-3-[3-(trifluoroacetyl)-
5. Experimental section
5.1. Chemistry
2,3,4,5-tetrahydro-1H-3-benzazepin-7-yl]propyl}piperi-
dine-1-carboxylate (15b). Aluminum chloride (10.0 g,
75.0 mmol) was added portionwise to a mixture of 13
(8.87 g, 25.0 mmol) and 3-(trifluoroacetyl)-2,3,4,5-tetra-
hydro-1H-3-benzazepine 14b8 (6.08 g, 25.0 mmol) in
CH2Cl2 (30 mL) at room temperature. The mixture was
stirred at room temperature for 12 h. The reaction mix-
ture was poured into ice, extracted with EtOAc, dried
over MgSO4, and concentrated to give a pale yellow
oil. The oil was subjected to chromatography on SiO2
(100 g, Hex–EtOAc = 2:1–1:1) and crystallized from
EtOH–Et2O to afford 15b as colorless crystals (5.02 g,
36%). Mp 132–133 ꢁC. IR (KBr) 2938, 1682, 1520,
Melting points were determined on a Yanagimoto mi-
cro-melting point apparatus and were uncorrected.
Infrared (IR) spectra were obtained on Jasco IR-810.
1H NMR spectra were taken on Varian Gemini 200
(200 MHz) or Mercury 300 (300 MHz) spectrometers.
Chemical shifts were given in ppm with tetramethyl-
silane as the internal standard. The following abbrevia-
tions were used: s = singlet, d = doublet, t = triplet,
m = multiplet, dd = double doublet, dt = double triplet,
br = broad. Elemental analyses (C, H, N) were mea-
sured on Vario EL (EL-04) instrument. Column chro-
matography was carried out using Merck silica gel 60
(63–200 lm). TLC was performed on silica gel 60 F254
(Merck), and the spots were detected by UV light (wave-
1
1346, 770 cmÀ1. H NMR (300 MHz, CDCl3) d 1.10–
1.30 (m, 2H), 1.45–1.65 (m, 1H), 1.65–1.90 (m, 4H),
2.70–2.95 (m, 2H), 2.95–3.20 (m, 6H), 3.65–3.85 (m,
4H), 4.10–4.30 (m, 2H), 5.22 (s, 2H), 7.20–7.30 (m,
1H), 7.51 (d, J = 8.4 Hz, 2H), 7.70–7.80 (m, 2H), 8.22

1906
Y. Ishichi et al. / Bioorg. Med. Chem. 13 (2005) 1901–1911
(d, J = 8.4 Hz, 2H). Anal. Calcd for C28H30F3N3O6: C,
59.89; H, 5.38; N, 7.48. Found: C, 59.84; H, 5.31; N, 7.47.
3H · 1/2), 2.10 (s, 3H · 1/2), 2.58 (t, J = 12.0 Hz, 2H),
2.90–3.10 (m, 6H), 3.70–3.80 (m, 2H · 1/2), 3.80–3.90
(m, 2H · 1/2), 4.54 (s, 2H · 1/2), 4.60 (s, 2H · 1/2),
7.20–7.30 (m, 1H), 7.75–7.80 (m, 1H+1H · 1/2), 7.93
(s, 1H · 1/2).
The following compounds 15a,c were prepared in a simi-
lar manner to that described for 15b. The compounds
were obtained as a mixture of amide bond isomers and
were used for the next reaction after appropriate identi-
5.1.8. 7-(3-Piperidin-4-yl-propanoyl)-2,3-dihydro-1,4-benz-
oxazepine-4(5H)-carbaldehyde (16c). 89%, Amorphous.
1
fication (e.g. H NMR).
1
IR (KBr) 2921, 1674, 1603, 1427, 733 cmÀ1. H NMR
5.1.4. 4-Nitrobenzyl 4-[3-(2-acetyl-2,3,4,5-tetrahydro-1H-
2-benzazepin-8-yl)-3-oxopropyl]piperidine-1-carboxylate
(15a). 24%, Amorphous. 1H NMR (200 MHz, CDCl3) d
1.05–1.30 (m, 2H), 1.40–1.90 (m, 7H), 2.05 (s, 3H · 1/2),
2.11 (s, 3H · 1/2), 2.65–3.10 (m, 6H), 3.70–3.80 (m,
2H · 1/2), 3.80–3.90 (m, 2H · 1/2), 4.10–4.30 (m, 2H),
4.55 (s, 2H · 1/2), 4.60 (s, 2H · 1/2), 5.22 (s, 2H),
7.20–7.30 (m, 1H), 7.51 (d, J = 8.4 Hz, 2H), 7.75–7.80
(m, 1H+1H · 1/2), 7.93 (s, 1H · 1/2), 8.22 (d,
J = 8.4 Hz, 2H).
(300 MHz, CDCl3) d 1.05–1.55 (m, 2H), 1.60–1.90 (m,
5H), 2.50–2.70 (m, 3H), 2.96 (t, J = 7.5 Hz, 2H), 3.00–
3.15 (m, 2H), 3.79 (t, J = 4.5 Hz, 1H), 3.94 (t,
J = 4.5 Hz, 1H), 4.10–4.20 (m, 2H), 4.55 (s, 2H · 1/2),
4.67 (s, 2H · 1/2), 7.07 (d, J = 4.5 Hz, 1H), 7.10 (d,
J = 4.5 Hz, 1H), 7.80–8.00 (m, 2H), 8.09 (s, 1H · 1/2),
8.22 (s, 1H · 1/2).
5.1.9.
3-(1-Benzylpiperidin-4-yl)-1-[3-(trifluoroacetyl)-
2,3,4,5-tetrahydro-1H-3-benzazepin-7-yl]propan-1-one
(17b). Benzyl bromide (600 mg, 3.51 mmol) was
added dropwise to a suspension of 16b (1.34 g,
3.50 mmol) and NaHCO3 (0.6 g, 7 mmol) in CH3CN
(10 mL) at room temperature. The mixture was stirred
at room temperature for 5 h, then concentrated in
vacuo, and the residue was diluted with EtOAc.
The organic phase was washed with brine, dried
over MgSO4, and concentrated to give a pale yellow
oil. The oil was subjected to chromatography on
SiO2 (10 g, Hex–EtOAc = 1:1) to afford 17b as a
colorless oil (1.01 g, 61%). 1H NMR (200 MHz,
CDCl3) d 1.20–1.45 (m, 3H), 1.60–1.80 (m, 4H),
1.85–2.05 (m, 2H), 2.80–3.10 (m, 8H), 3.49 (s, 2H),
3.65–3.85 (m, 4H), 7.20–7.40 (m, 6H), 7.70–7.80 (m,
2H).
5.1.5. 4-Nitrobenzyl 4-[3-(4-formyl-2,3,4,5-tetrahydro-
1,4-benzoxazepin-7-yl)-3-oxopropyl]piperidine-1-carbox-
ylate (15c). 83%, Amorphous. IR (KBr) 2926, 2680,
1678, 1605, 1522, 1346, 1236, 735 cmÀ1 1H NMR
.
(300 MHz, CDCl3) d 1.10–1.30 (m, 2H), 1.45–1.85 (m,
5H), 2.70–2.95 (m, 2H), 2.98 (t, J = 7.5 Hz, 2H), 3.75–
3.80 (m, 2H · 1/2), 3.90–3.95 (m, 2H · 1/2), 4.10–4.30
(m, 4H), 4.56 (s, 2H · 1/2), 4.67 (s, 2H · 1/2), 5.22 (s,
2H), 7.08 (d, J = 3.6 Hz, 1H · 1/2), 7.11 (d, J = 3.9 Hz,
1H · 1/2), 7.45–7.55 (m, 2H), 7.80–7.85 (m, 2H), 7.94
(s, 1H · 1/2), 8.09 (s, 1H · 1/2), 8.20–8.25 (m, 2H).
5.1.6. 3-Piperidin-4-yl-1-[3-(trifluoroacetyl)-2,3,4,5-tetra-
hydro-1H-3-benzazepin-7-yl]propan-1-one (16b). Com-
pound 15b (4.60 g, 8.19 mmol) was dissolved in EtOH
(150 mL) and THF (50 mL), and was hydrogenated at
room temperature with 10% Pd–C (wet, 1.0 g) as cata-
lyst at atmospheric pressure. The mixture was stirred
for 90 min under hydrogen atmosphere. The catalyst
was removed by filtration, and the filtrate was concen-
trated in vacuo. The residue was subjected to chroma-
tography on SiO2 (60 g, EtOAc–MeOH = 9:1) and
crystallized from EtOH–Et2O to afford 16b as colorless
crystals (1.86 g, 59%). Mp 124–125 ꢁC (EtOH–Et2O).
The following compounds 17a,c were prepared in a simi-
lar manner to that described for 17b. The compounds
were obtained as a mixture of amide bond isomers and
were used for next reaction after appropriate identifica-
1
tion (e.g. H NMR).
5.1.10. 1-(2-Acetyl-2,3,4,5-tetrahydro-1H-2-benzazepin-
8-yl)-3-(1-benzylpiperidin-4-yl)propan-1-one (17a). 66%,
1
1
IR (KBr) 2924, 1682, 1464, 1167, 756 cmÀ1. H NMR
Amorphous. H NMR (300 MHz, CDCl3) d 1.20–1.40
(m, 3H), 1.60–1.75 (m, 4H), 1.80–1.90 (m, 2H), 1.90–
2.00 (m, 2H), 2.04 (s, 3H · 1/2), 2.11 (s, 3H · 1/2),
2.80–3.05 (m, 6H), 3.49 (s, 2H), 3.70–3.75 (m, 2H ·
1/2), 3.80–3.90 (m, 2H · 1/2), 4.54 (s, 2H · 1/2), 4.59
(s, 2H · 1/2), 7.20–7.40 (m, 6H), 7.75–7.80 (m,
1H+1H · 1/2), 7.93 (s, 1H · 1/2).
(300 MHz, CDCl3) d 1.10–1.30 (m, 2H), 1.35–1.55 (m,
1H), 1.60–1.80 (m, 4H), 2.00–2.20 (br, 1H), 2.60 (dt,
J = 12.0, 2.4 Hz, 2H), 2.97 (t, J = 7.5 Hz, 2H), 3.00–
3.20 (m, 6H), 3.65–3.85 (m, 4H), 7.20–7.30 (m, 1H),
7.75–7.80 (m, 2H). Anal. Calcd for C20H25F3N2O2Æ0.25-
H2O: C, 62.08; H, 6.64; N, 7.24. Found: C, 61.79; H,
6.50; N, 6.95.
5.1.11. 7-[3-(1-Benzylpiperidin-4-yl)propanoyl]-2,3-dihy-
dro-1,4-benzoxazepine-4(5H)-carbaldehyde (17c). 58%,
Amorphous. IR (KBr) 2922, 1682, 1603, 1451,
The following compounds 16a,c were prepared in a simi-
lar manner to that described for 16b. The compounds
were obtained as a mixture of amide bond isomers and
were used for next reaction after appropriate identifica-
734 cmÀ1 1H NMR (300 MHz, CDCl3) d 1.20–1.40
.
(m, 3H), 1.60–1.80 (m, 4H), 2.80–3.00 (m, 4H), 3.49 (s,
2H), 3.77 (t, J = 4.8 Hz, 1H), 3.93 (t, J = 4.8 Hz, 1H),
4.10–4.20 (m, 2H), 4.53 (s, 2H · 1/2), 4.65 (s, 2H ·
1/2), 7.05 (d, J = 4.2 Hz, 1H · 1/2), 7.08 (d, J = 4.2 Hz,
1H · 1/2), 7.20–7.35 (m, 5H), 7.75–7.80 (m,
1H+1H · 1/2), 7.90–7.95 (m, 1H · 1/2), 8.06 (s, 1H · 1/
2), 8.20 (s, 1H · 1/2).
1
tion (e.g., H NMR).
5.1.7. 1-(2-Acetyl-2,3,4,5-tetrahydro-1H-2-benzazepin-8-
yl)-3-piperidin-4-yl-propan-1-one (16a). 72%, Amor-
phous. 1H NMR (300 MHz, CDCl3) d 1.05–1.30 (m,
2H), 1.35–1.50 (m, 1H), 1.60–1.90 (m, 7H), 2.03 (s,

Y. Ishichi et al. / Bioorg. Med. Chem. 13 (2005) 1901–1911
1907
5.1.12. 3-(1-Benzylpiperidin-4-yl)-1-(2,3,4,5-tetrahydro-
1H-2-benzazepin-8-yl)propan-1-one dihydrochloride
36.9 mmol) in 1,2-dichloroethane (10 mL) at room tem-
perature. The mixture was stirred at room temperature
for 12 h. The reaction mixture was poured into ice, ex-
tracted with EtOAc (4 times), dried over MgSO4, and
concentrated to give a pale yellow oil. The oil was sub-
jected to chromatography on SiO2 (50 g, EtOAc:
MeOH = 10:1) to afford 20b as colorless crystals
(12.3 g, 94%). Recrystallization from MeOH–EtOAc
gave 11.8 g of 20b. Mp 157–159 ꢁC. IR (KBr) 2928,
1672, 1640, 1597, 1493, 1446, 1381, 1152, 972,
(5).7a A solution of 17a (1.27 g, 3.03 mmol) in concen-
trated HCl (20 mL) was stirred at 120 ꢁC for 12 h. The
mixture was concentrated to give 5 as a pale yellow
amorphous (1.20 g, 88%), which was crystallized from
ethanol to afford colorless crystals. Mp 147–150 ꢁC. IR
(KBr) 2921, 1682, 1604, 1452, 740 cmÀ1. 1H NMR (free
base; 300 MHz, CDCl3) d 1.20–1.40 (m, 3H), 1.55–1.80
(m, 7H), 1.85–2.00 (m, 2H), 2.80–3.10 (m, 6H), 3.21 (t,
J = 5.4 Hz, 2H), 3.47 (s, 2H), 3.98 (s, 2H), 7.20–7.35
(m, 6H), 7.65–7.75 (m, 2H). Anal. Calcd for
C25H32N2OÆ2HClÆ0.5H2O: C, 65.49; H, 7.69; N, 6.11.
Found: C, 65.60; H, 7.66; N, 6.08.
750 cmÀ1 1H NMR (200 MHz, CDCl3) d 1.00–1.30
.
(m, 2H), 1.50–1.95 (m, 5H), 2.09 (s, 3H), 2.53 (dt,
J = 12.9, 2.4 Hz, 1H), 2.72 (t, J = 7.6 Hz, 2H), 2.90–
3.15 (m, 5H), 3.24 (t, J = 8.6 Hz, 2H), 3.75–3.90 (m,
1H), 4.14 (t, J = 8.6 Hz, 2H), 4.55–4.70 (m, 1H), 7.68
(s, 1H), 7.73 (s, 1H). Anal. Calcd for C21H26N2O3: C,
71.16; H, 7.39; N, 7.90. Found: C, 71.11; H, 7.58; N,
7.82.
5.1.13. 3-(1-Benzylpiperidin-4-yl)-1-(2,3,4,5-tetrahydro-
1H-3-benzazepin-7-yl)propan-1-one dihydrochloride (6).
A mixture of 17b (1.00 g, 2.12 mmol), saturated aqueous
K2CO3 (10 mL), H2O (10 mL), and MeOH (30 mL) was
stirred at room temperature for 12 h. The mixture was
concentrated in vacuo, extracted with EtOAc (3 times),
and the extract was washed with brine. The organic
phase was dried over MgSO4 and concentrated to give
a colorless oil. The oil was subjected to chromatography
on basic SiO2 (20 g, EtOAc–MeOH = 9:1) to afford a
free base of 6 as a colorless oil (602 mg, 75%). The free
base (602 mg) was treated with HCl–EtOH and crystal-
lized from EtOH–Et2O to give 6 as colorless crystals.
Mp 232–234 ꢁC. IR (KBr) 2948, 2728, 1680, 1456,
The following compounds, 20a, 20c, and 20d, were pre-
pared in a similar manner to that described for 20b.
5.1.16. 8-[3-(1-Acetylpiperidin-4-yl)propanoyl]-5,6-dihy-
dro-4H-pyrrolo[3,2,1-ij]quinolin-2(1H)-one (20a). 80%,
Mp 80–82 ꢁC (EtOH–Et2O). IR (KBr) 2930, 1715,
1622, 1495, 1343, 1152, 731 cmÀ1
.
1H NMR
(300 MHz, CDCl3) d 1.05–1.30 (m, 2H), 1.50–2.10 (m,
7H), 2.09 (s, 3H), 2.53 (dt, J = 8.7, 2.0 Hz, 1H), 2.83
(t, J = 6.0 Hz, 2H), 2.90–3.10 (m, 3H), 3.56 (s, 2H),
3.70–3.85 (m, 3H), 4.55–4.65 (m, 1H), 7.73 (s, 2H). Anal.
Calcd for C21H26N2O3Æ0.5H2O: C, 69.40; H, 7.49; N,
7.71. Found: C, 69.50; H, 7.79; N, 7.44.
752 cmÀ1 1H NMR (free base; 300 MHz, CDCl3) d
.
1.20–1.40 (m, 3H), 1.65–1.75 (m, 4H), 1.90–2.00 (m,
3H), 2.80–3.05 (m, 12H), 3.48 (s, 2H), 7.10–7.40 (m,
6H), 7.65–7.75 (m, 2H, 6-H, and 8-H of 3-benzazepine).
Anal. Calcd for C25H32N2OÆ2HClÆ0.25H2O: C, 66.14; H,
7.66; N, 6.17. Found: C, 66.44; H, 7.82; N, 6.19.
5.1.17.
tetrahydro-1H,5H-pyrido[3,2,1-ij]quinolin-5-one
85%, Mp 135–136 ꢁC (EtOH–Et2O). IR (KBr) 2930,
1674, 1435, 1159, 752 cmÀ1 1H NMR (200 MHz,
9-[3-(1-Acetylpiperidin-4-yl)propanoyl]-2,3,6,7-
(20c).
5.1.14. 3-(1-Benzylpiperidin-4-yl)-1-(2,3,4,5-tetrahydro-
1,4-benzoxazepin-7-yl)propan-1-one dihydrochloride (7).
A solution of 17c (2.41 g, 5.93 mmol) in concentrated
HCl (10 mL) and MeOH (10 mL) was stirred at reflux
for 1 h. The mixture was concentrated and crystallized
from EtOH to give 7 as colorless crystals (1.17 g,
44%). Mp 234–236 ꢁC; IR (KBr) 2919, 1678, 1601,
.
CDCl3) d 1.00–1.30 (m, 2H), 1.45–1.85 (m, 5H), 1.90–
2.05 (m, 2H), 2.09 (s, 3H), 2.53 (dt, J = 12.8, 2.6 Hz,
1H), 2.65–2.70 (m, 2H), 2.85 (t, J = 6.2 Hz, 2H), 2.90–
3.10 (m, 5H), 3.70–3.90 (m, 3H), 4.55–4.70 (m, 1H),
7.61 (s, 2H). Anal. Calcd for C22H28N2O3: C, 71.71;
H, 7.66; N, 7.60. Found: C, 71.63; H, 7.78; N, 7.61.
1
1494, 1236, 740 cmÀ1. H NMR (free base; 300 MHz,
CDCl3) d 1.20–1.45 (m, 3H), 1.60–2.10 (m, 7H), 2.80–
3.00 (m, 4H), 3.24 (t, J = 4.5 Hz, 2H), 3.50 (s, 2H),
4.01 (s, 2H), 4.10 (t, J = 4.5 Hz, 2H), 7.06 (d,
J = 8.1 Hz, 1H), 7.20–7.35 (m, 5H), 7.75–7.80 (m, 2H).
Anal. Calcd for C24H30N2O2Æ2HClÆ0.5H2O: C, 62.61;
H, 7.22; N, 6.08. Found: C, 62.55; H, 7.05; N, 6.10.
5.1.18.
9-[3-(1-Acetylpiperidin-4-yl)propanoyl]-1,2,6,7-
tetrahydroazepino[3,2,1-hi]indol-4(5H)-one (20d). 63%,
Mp 93–95 ꢁC (EtOH–Et2O). IR (KBr) 2928, 2859,
1713, 1605, 1146, 754 cmÀ1
.
1H NMR (200 MHz,
CDCl3) d 1.00–1.30 (m, 2H), 1.45–1.85 (m, 7H), 1.90–
2.25 (m, 2H), 2.09 (s, 3H), 2.53 (dt, J = 12.8, 2.6 Hz,
1H), 2.90–3.10 (m, 6H), 3.56 (s, 2H), 3.75–3.90 (m,
1H), 3.95–4.05 (m, 2H), 4.55–4.70 (m, 1H), 7.66 (s,
1H), 7.68 (s, 1H). Anal. Calcd for C22H28N2O3Æ0.1H2O:
C, 71.36; H, 7.68; N, 7.57. Found: C, 71.29; H, 7.81; N,
7.63.
5.1.15.
8-[3-(1-Acetylpiperidin-4-yl)propanoyl]-1,2,5,6-
tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-one (20b). 3-
(1-Acetyl-4-piperidinyl)propanoic acid (18)11 (8.82 g,
44.3 mmol) was added portionwise to thionyl chloride
(20 mL) at 0 ꢁC with stirring. The mixture was stirred
at room temperature for 20 min. The reaction mixture
was concentrated in vacuo, and the residue was collected
by filtration, washed with Et2O to give the correspond-
ing acid chloride of 18 as a colorless solid. Aluminum
chloride (16.2 g, 121 mmol) was added portionwise
to a mixture of the acid chloride and 1,2,5,6-tetra-
hydro-4H-pyrrolo[3,2,1-ij]quinolin-4-one19b10 (6.40 g,
5.1.19. 8-(3-Piperidin-4-yl-propanoyl)-1,2,5,6-tetrahydro-
4H-pyrrolo[3,2,1-ij]quinolin-4-one (21b). A solution of
20b (11.9 g, 33.5 mmol) in concentrated HCl (60 mL)
was stirred at 140 ꢁC for 4 h. The reaction mixture was
concentrated in vacuo, and the residue was adjusted to
pH 12 using aqueous 8 N NaOH solution, and extracted
with EtOAc. The organic phase was washed with brine,

1908
Y. Ishichi et al. / Bioorg. Med. Chem. 13 (2005) 1901–1911
dried over MgSO4, and concentrated. The residue was
crystallized from EtOAc–Et2O to afford 21b (10.4 g,
99%). mp 114–115 ꢁC (EtOH–Et2O). IR (KBr) 1914,
2.38 mmol) was treated with an excess amount of 10 N
HCl in EtOH, and crystallized from EtOH–Et2O to give
9c as colorless crystals (1.03 g, 95%). Mp 201–203 ꢁC. IR
(KBr) 1652, 1594, 1259, 1149 cmÀ1. Anal. Calcd for
C26H29FN2O2ÆHCl: C, 68.34; H, 6.62; N, 6.13. Found:
C, 68.15; H, 6.66; N, 6.04.
1672, 1597, 1493, 1381, 1157, 754 cmÀ1 1H NMR
.
(200 MHz, CDCl3) d 1.00–1.30 (m, 2H), 1.30–1.90 (m,
7H), 2.59 (dt, J = 12.0, 2.4 Hz, 2H), 2.72 (t,
J = 7.6 Hz, 2H), 2.85–3.15 (m, 5H), 3.23 (t, J = 8.6 Hz,
2H), 4.14 (t, J = 8.6 Hz, 2H), 7.68 (s, 1H), 7.73 (s,
1H). Anal. Calcd for C19H24N2O2: C, 73.05; H, 7.74;
N, 8.97. Found: C, 72.62; H, 7.76; N, 8.87.
The following compounds, 8, 10, 11, 9a,b, and 9d–s,
were prepared in a similar manner to that described
for 9c.
The following compounds, 21a, 21c, and 21d, were pre-
pared in a similar manner to that described for 21b.
5.1.24. 8-[3-(1-Benzylpiperidin-4-yl)propanoyl]-5,6-dihy-
dro-4H-pyrrolo[3,2,1-ij]quinolin-2(1H)-one hydrochloride
(8). 85%, Mp 244–246 ꢁC (EtOH–Et2O). IR (KBr) 1718,
5.1.20.
8-(3-Piperidin-4-yl-propanoyl)-5,6-dihydro-4H-
1670, 1604, 1344, 1147 cmÀ1 1H NMR (free base;
.
pyrrolo[3,2,1-ij]quinolin-2(1H)-one (21a). 31%, Mp 134–
136 ꢁC (EtOH–Et2O). IR (KBr) 2926, 1715, 1671,
200 MHz, CDCl3) d 1.20–1.42 (m, 3H), 1.61–1.77 (m,
4H), 1.85–2.08 (m, 4H), 2.78–2.96 (m, 6H), 3.48 (s,
2H), 3.54 (s, 2H), 3.71–3.77 (m, 2H), 7.22–7.33 (m,
5H), 7.72 (s, 2H). Anal. Calcd for C26H30N2O2ÆH-
ClÆ0.25H2O: C, 70.41; H, 7.15; N, 6.31. Found: C,
70.26; H, 7.26; N, 6.20.
1603, 1497, 1343, 1155, 752 cmÀ1
.
1H NMR
(200 MHz, CDCl3) d 1.00–1.25 (m, 2H), 1.30–1.80 (m,
7H), 1.95–2.10 (m, 2H), 2.58 (dt, J = 12.0, 2.4 Hz, 2H),
2.83 (t, J = 6.2 Hz, 2H), 2.94 (t, J = 7.6 Hz, 2H), 3.00–
3.15 (m, 2H), 3.55 (s, 2H), 3.74 (t, J = 6.2 Hz, 2H),
7.73 (s, 2H). Anal. Calcd for C19H24N2O2Æ0.25H2O: C,
72.01; H, 7.79; N, 8.84. Found: C, 72.46; H, 7.87; N,
8.88.
5.1.25. 9-[3-(1-Benzylpiperidin-4-yl)propanoyl]-2,3,6,7-
tetrahydro-1H,5H-pyrido[3,2,1-ij]quinolin-5-one hydro-
chloride (10). 86%, Mp 236–238 ꢁC (EtOH–Et2O). IR
(KBr) 2938, 1669, 1603, 1364, 1167, 750 cmÀ1 1H
.
5.1.21. 9-(3-Piperidin-4-yl-propanoyl)-2,3,6,7-tetrahydro-
1H,5H-pyrido[3,2,1-ij]quinolin-5-one (21c). 72%, Mp 87–
88 ꢁC (EtOH–Et2O). IR (KBr) 2922, 1674, 1603, 1483,
NMR (free base; 300 MHz, CDCl3) d 1.20–1.40 (m,
3H), 1.60–1.75 (m, 4H), 1.80–2.00 (m, 4H), 2.65–2.79
(m, 2H), 2.80–3.00 (m, 8H), 3.48 (s, 2H), 3.89 (t,
J = 6.0 Hz, 2H), 7.20–7.35 (m, 5H), 7.60 (s, 1H), 7.61
(s, 1H). Anal. Calcd for C27H32N2O2ÆHClÆ0.25H2O: C,
70.88; H, 7.38; N, 6.12. Found: C, 70.79; H, 7.49; N,
6.13.
1
1163, 752 cmÀ1. H NMR (200 MHz, CDCl3) d 1.00–
1.30 (m, 2H), 1.35–1.80 (m, 5H), 1.90–2.05 (m, 2H),
2.59 (dt, J = 12.0, 2.4 Hz, 2H), 2.65–2.75 (m, 2H),
2.90–3.15 (m, 9H), 3.89 (t, J = 5.8 Hz, 2H), 7.62 (s,
2H). Anal. Calcd for C20H26N2O2: C, 73.59; H, 8.03;
N, 8.58. Found: C, 73.39; H, 8.12; N, 8.43.
5.1.26. 9-[3-(1-Benzylpiperidin-4-yl)propanoyl]-1,2,6,7-
tetrahydroazepino[3,2,1-hi]indol-4(5H)-one hydrochloride
(11). 80%, Mp 209–211 ꢁC (EtOH–Et2O). IR (KBr)
5.1.22. 9-(3-Piperidin-4-yl-propanoyl)-1,2,6,7-tetrahydro-
azepino[3,2,1-hi]indol-4(5H)-one (21d). 61%, Amor-
phous. IR (KBr) 2926, 1717, 1672, 1603, 1337, 1151,
1
2928, 1738, 1603, 1143, 737 cmÀ1. H NMR (free base;
300 MHz, CDCl3) d 1.20–1.40 (m, 2H), 1.45–2.20 (m,
11H), 2.60–3.10 (m, 5H), 3.16 (d, J = 12.6 Hz, 1H),
3.30 (d, J = 12.6 Hz, 1H), 3.49 (s, 2H), 3.49–4.10 (m,
3H), 6.80–7.40 (m, 5H), 7.62 (s, 1H), 7.99 (s, 1H). Anal.
Calcd for C27H32N2O2ÆHClÆ0.5H2O: C, 70.19; H, 7.42;
N, 6.06. Found: C, 69.78; H, 7.37; N, 6.03.
733 cmÀ1 1H NMR (200 MHz, CDCl3) d 1.00–1.30
.
(m, 2H), 1.35–1.90 (m, 6H), 1.95–2.20 (m, 4H), 2.58
(dt, J = 8.1, 1.6 Hz, 2H), 2.85–3.15 (m, 6H), 3.56 (s,
2H), 3.98 (t, J = 5.8 Hz, 2H), 7.66 (s, 1H), 7.68 (s, 1H).
5.1.23. 8-{3-[1-(3-Fluorobenzyl)piperidin-4-yl]propanoyl}-
1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-one hy-
drochloride (9c). 3-Fluorobenzyl bromide (660 mg,
3.49 mmol) was added dropwise to a suspension of 21b
(1.04 g, 3.32 mmol) and K2CO3 (0.8 g, 5.8 mmol) in
CH3CN (10 mL) at room temperature. The mixture
was stirred at room temperature for 12 h, then concen-
trated in vacuo, and the residue was diluted with EtOAc.
The organic phase was washed with brine, dried over
MgSO4, and concentrated to give a pale yellow oil.
Crystallization from EtOH–Et2O afforded the free base
of 9c (1.31 g, 94%). Mp 111–112 ꢁC. 1H NMR (free
base; 200 MHz, CDCl3) d 1.20–1.50 (4H, m), 1.55–1.80
(4H, m), 1.85–2.05 (2H, m), 2.71 (2H, t, J = 7.6 Hz),
2.80–3.15 (5H, m), 3.22 (2H, t, J = 8.6 Hz), 3.47 (2H,
s), 4.13 (2H, t, J = 8.6 Hz), 6.85–7.15 (3H, m), 7.20–
7.35 (1H, m), 7.67 (1H, s), 7.72 (1H, s). Anal. Calcd
for C26H29FN2O2: C, 74.26; H, 6.95; N, 6.66. Found:
C, 74.28; H, 7.02; N, 6.58. The free base (1.00 g,
5.1.27. 8-[3-(1-Benzylpiperidin-4-yl)propanoyl]-1,2,5,6-
tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-one hydrochlo-
ride (9a). 80%, Mp 245–248 ꢁC (EtOH–Et2O). IR
(KBr) 3026, 1672, 1595 cmÀ1 1H NMR (free base;
.
200 MHz, CDCl3) d 1.19–1.43 (m, 3H), 1.60–2.03 (m,
6H), 2.71 (t, J = 7.6 Hz, 2H), 2.81–3.09 (m, 6H), 3.22
(t, J = 8.6 Hz, 2H), 3.48 (s, 2H), 4.13 (t, J = 8.6 Hz,
2H), 7.20–7.32 (m, 5H), 7.66 (s, 1H), 7.70 (s, 1H). Anal.
Calcd for C26H30N2O2ÆHCl: C, 71.14; H, 7.12; N, 6.38.
Found: C, 70.97; H, 7.14; N, 6.18.
5.1.28. 8-3-[1-(2-Fluorobenzyl)piperidin-4-yl]propanoyl-
1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-one hy-
drochloride (9b). 81%, Mp 110–112 ꢁC (EtOH–Et2O).
1
IR (KBr) 1644, 1590, 1234, 1148 cmÀ1. H NMR (free
base; 200 MHz, CDCl3) d 1.18–1.43 (m, 3H), 1.60–1.80
(m, 4H), 1.91–2.13 (m, 2H), 2.71 (t, J = 7.8 Hz, 2H),
2.83–3.10 (m, 6H), 3.22 (t, J = 8.6 Hz, 2H), 3.56

Y. Ishichi et al. / Bioorg. Med. Chem. 13 (2005) 1901–1911
1909
(s, 2H), 4.13 (t, J = 8.6 Hz, 2H), 6.94–7.41 (m, 4H), 7.66
(s, 1H), 7.70 (s, 1H). Anal. Calcd for C26H29FN2O2ÆH-
ClÆ2.5H2O: C, 62.21; H, 7.03; N, 5.58. Found: C,
62.17; H, 6.73; N, 5.40.
H2O: C, 63.09; H, 7.45; N, 5.45. Found: C, 63.10; H,
7.21; N, 5.30.
5.1.34. 8-{3-[1-(3-Methoxybenzyl)piperidin-4-yl]propa-
noyl}-1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-
one hydrochloride (9i). 84%, Mp 157–159 ꢁC (EtOH–
5.1.29. 8-{3-[1-(4-Fluorobenzyl)piperidin-4-yl]propanoyl}-
1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-one hy-
drochloride (9d). 84%, Mp 245 ꢁC (Decomposed),
Et2O). IR (KBr) 2915, 1665, 1597, 1490 cmÀ1 1H
.
NMR (free base; 200 MHz, CDCl3) d 1.22–1.43 (m,
3H), 1.59–1.76 (m, 4H), 1.83–2.05 (m, 2H), 2.71 (t,
J = 7.9 Hz, 2H), 2.86–3.06 (m, 6H), 3.22 (t, J = 8.5 Hz,
2H), 3.26 (s, 2H), 3.81 (s, 3H), 4.13 (t, J = 8.5 Hz,
2H), 6.76–6.82 (m, 1H), 6.87–6.92 (m, 2H), 7.22 (t,
J = 8.4 Hz, 1H), 7.66 (s, 1H), 7.71 (s, 1H). Anal. Calcd
for C27H32N2O3ÆHClÆ0.5H2O: C, 67.84; H, 7.17; N,
5.86. Found: C, 67.96; H, 7.25; N, 5.70.
(EtOH–Et2O). IR (KBr) 1671, 1594, 1295, 1149 cmÀ1
.
1H NMR (free base; 200 MHz, CDCl3) d 1.18–1.42
(m, 3H), 1.60–1.81 (m, 4H), 1.83–2.06 (m, 2H), 2.71 (t,
J = 7.8 Hz, 2H), 2.80–3.08 (m, 6H), 3.22 (t, J = 8.4 Hz,
2H), 3.44 (s, 2H), 4.13 (t, J = 8.4 Hz, 2H), 6.91–7.03
(m, 2H), 7.19–7.33 (m, 2H), 7.66 (s, 1H), 7.70 (s, 1H).
Anal. Calcd for C26H29FN2O2ÆHCl: C, 68.34; H, 6.62;
N, 6.13. Found: C, 68.01; H, 6.56; N, 5.99.
5.1.35.
8-3-[1-(4-Methoxybenzyl)piperidin-4-yl]propa-
5.1.30. 8-{3-[1-(2-Chlorobenzyl)piperidin-4-yl]propano-
yl}-1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-one
hydrochloride (9e). 79%, Mp 191–193 ꢁC (EtOH–Et2O).
noyl-1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-
one hydrochloride (9j). 61%, Amorphous. IR (KBr) 1654,
1596, 1492, 1382, 1255 cmÀ1 1H NMR (free base;
.
IR (KBr) 1659, 1594, 1162, 1147 cmÀ1
.
1H NMR
200 MHz, CDCl3) d 1.23–1.49 (m, 3H), 1.61–1.79 (m,
4H), 1.96–2.17 (m, 2H), 2.72 (t, J = 7.7 Hz, 2H), 2.87–
3.06 (m, 6H), 3.22 (t, J = 8.6 Hz, 2H), 3.43 (s, 2H),
3.77 (s, 3H), 4.12 (t, J = 8.5 Hz, 2H), 6.83 (d,
J = 8.5 Hz, 2H), 7.20 (d, J = 8.5 Hz, 2H), 7.67 (s, 1H),
7.72 (s, 1H). Anal. Calcd for C27H32N2O3ÆHClÆ0.75H2O:
C, 67.21; H, 7.21; N, 5.81. Found: C, 67.31; H, 7.05; N,
5.75.
(free base; 200 MHz, CDCl3) d 1.20–1.48 (m, 3H),
1.58–1.82 (m, 4H), 1.93–2.15 (m, 2H), 2.71 (t,
J = 7.6 Hz, 2H), 2.84–3.09 (m, 6H), 3.22 (t, J = 8.6 Hz,
2H), 3.59 (s, 2H), 4.13 (t, J = 8.6 Hz, 2H), 7.15–7.36
(m, 3H), 7.42–7.52 (m, 1H), 7.67 (s, 1H), 7.71 (s, 1H).
Anal. Calcd for C26H29ClN2O2ÆHClÆ0.5H2O: C, 64.73;
H, 6.48; N, 5.81. Found: C, 65.42; H, 6.49; N, 5.79.
5.1.31.
8-{3-[1-(3-Chlorobenzyl)piperidin-4-yl]propa-
5.1.36.
8-{3-[1-(2-Hydroxybenzyl)piperidin-4-yl]propa-
noyl}-1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-
one hydrochloride (9f). 86%, Mp 208–210 ꢁC (EtOH–
noyl}-1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-
one hydrochloride (9k). 47%, Mp 223–225 ꢁC (EtOH–
Et2O). IR (KBr) 1654, 1596, 1162, 1149 cmÀ1
.
1H
Et2O). IR (KBr) 3543, 1661, 1592, 1270, 1148 cmÀ1
.
NMR (free base; 200 MHz, CDCl3) d 1.19–1.42 (m,
3H), 1.58–1.79 (m, 4H), 1.86–2.02 (m, 2H), 2.71 (t,
J = 7.7 Hz, 2H), 2.81–3.08 (m, 6H), 3.22 (t, J = 8.6 Hz,
2H), 3.45 (s, 2H), 4.13 (t, J = 8.6 Hz, 2H), 7.16–7.28
(m, 3H), 7.32 (s, 1H), 7.66 (s, 1H), 7.71 (s, 1H). Anal.
Calcd for C26H29ClN2O2ÆHClÆ0.5H2O: C, 64.73; H,
6.48; N, 5.81. Found: C, 64.97; H, 6.39; N, 5.65.
1H NMR (free base; 200 MHz, CDCl3) d 1.20–1.53
(m, 3H), 1.60–1.84 (m, 4H), 1.98–2.16 (m, 3H), 2.72 (t,
J = 7.8 Hz, 2H), 2.84–3.10 (m, 6H), 3.23 (t, J = 8.6 Hz,
2H), 3.68 (s, 2H), 4.13 (t, J = 8.6 Hz, 2H), 6.70–6.85
(m, 2H), 6.88–7.00 (m, 1H), 7.12–7.23 (m, 1H), 7.67 (s,
1H), 7.71 (s, 1H). Anal. Calcd for C26H30N2O3ÆHCl:
C, 68.63; H, 6.87; N, 6.16. Found: C, 68.48; H, 6.94;
N, 5.95.
5.1.32.
8-{3-[1-(4-Chlorobenzyl)piperidin-4-yl]propa-
noyl}-1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-
one hydrochloride (9g). 80%, Mp 235–237 ꢁC (EtOH–
5.1.37.
8-{3-[1-(3-Hydroxybenzyl)piperidin-4-yl]propa-
noyl}-1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-
one hydrochloride (9l). 36%, Mp 154–156 ꢁC (EtOH–
Et2O). IR (KBr) 1670, 1594, 1162, 1145 cmÀ1 1H
.
1
NMR (free base; 200 MHz, CDCl3) d 1.18–1.41 (m,
3H), 1.58–1.78 (m, 4H), 1.84–2.02 (m, 2H), 2.72 (t,
J = 7.7 Hz, 2H), 2.80–3.08 (m, 6H), 3.22 (t, J = 8.6 Hz,
2H), 3.44 (s, 2H), 4.13 (t, J = 8.6 Hz, 2H), 7.20–7.33
(m, 4H), 7.67 (s, 1H), 7.71 (s, 1H). Anal. Calcd for
C26H29ClN2O2ÆHClÆH2O: C, 63.54; H, 6.56; N, 5.70.
Found: C, 63.26; H, 6.53; N, 5.54.
Et2O). IR (KBr) 3182, 1667, 1592 cmÀ1. H NMR (free
base; 200 MHz, CDCl3) d 1.30–1.92 (m, 7H), 2.15–2.36
(m, 2H), 2.71 (t, J = 7.8 Hz, 2H), 2.82–3.31 (m, 8H),
3.64 (s, 2H), 4.12 (t, J = 8.4 Hz, 2H), 6.68–7.18 (m,
5H), 7.65 (s, 1H), 7.69 (s, 1H). Anal. Calcd for
C26H30N2O3ÆHClÆ1.5H2O: C, 64.79; H, 7.11; N, 5.81.
Found: C, 64.67; H, 6.82; N, 5.65.
5.1.33. 8-{3-[1-(2-Methoxybenzyl)piperidin-4-yl]propa-
noyl}-1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-
one hydrochloride (9h). 76%, Amorphous. IR (KBr)
5.1.38.
8-{3-[1-(4-Hydroxybenzyl)piperidin-4-yl]propa-
noyl}-1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-
one hydrochloride (9m). 11%, Mp 233–235 ꢁC (EtOH–
2922, 1671, 1596, 1491, 1151, 755, 729 cmÀ1. H NMR
Et2O). IR (KBr) 3432, 1652, 1591 cmÀ1. H NMR (free
1
1
(free base; 200 MHz, CDCl3) d 1.23–1.49 (m, 3H),
1.61–1.79 (m, 4H), 1.96–2.17 (m, 2H), 2.72 (t,
J = 7.7 Hz, 2H), 2.87–3.06 (m, 6H), 3.22 (t, J = 8.6 Hz,
2H), 3.58 (s, 2H), 3.82 (s, 3H), 4.14 (t, J = 8.6 Hz,
2H), 6.83–6.96 (m, 2H), 7.18–7.41 (m, 2H), 7.67 (s,
1H), 7.72 (s, 1H). Anal. Calcd for C27H32N2O3ÆHClÆ2.5-
base; 200 MHz, CDCl3) d 1.22–1.52 (m, 3H), 1.58–1.84
(m, 4H), 1.90–2.18 (m, 2H), 2.66–2.76 (m, 2H), 2.80–
3.10 (m, 6H), 3.21 (t, J = 8.4 Hz, 2H), 3.47 (s, 2H),
4.13 (t, J = 8.4 Hz, 2H), 5.98 (br, s, 1H), 6.64 (d,
J = 8.4 Hz, 2H), 7.08 (d, J = 8.4 Hz, 2H), 7.65 (s, 1H),
7.70 (s, 1H). Anal. Calcd for C26H30N2O3ÆHClÆ0.5H2O:

1910
Y. Ishichi et al. / Bioorg. Med. Chem. 13 (2005) 1901–1911
C, 67.30; H, 6.95; N, 6.04. Found: C, 67.46; H, 7.20; N,
5.86.
J = 8.4 Hz, 2H), 7.40 (t, J = 7.8 Hz, 1H), 7.50–7.65 (m,
3H), 7.67 (s, 1H), 7.71 (s, 1H). Anal. Calcd for
C27H29N3O2ÆHClÆ0.8H2O: C, 67.78; H, 6.66; N, 8.78.
Found: C, 67.79; H, 6.97; N, 8.51.
5.1.39. 8-{3-[1-(2-Nitrobenzyl)piperidin-4-yl]propanoyl}-
1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-one hy-
drochloride (9n). 85%, Mp 166–168 ꢁC (EtOH–Et2O).
IR (KBr) 2934, 1669, 1597, 1532, 1493, 1342,
5.1.44. 4-({4-[3-Oxo-3-(4-oxo-1,2,5,6-tetrahydro-4H-pyr-
rolo[3,2,1-ij]quinolin-8-yl)propyl]piperidin-1-yl}methyl)-
benzonitrile hydrochloride (9s). 78%, Mp 220–222 ꢁC
(EtOH–Et2O). IR (KBr) 2930, 2627, 2230, 1669, 1597,
750 cmÀ1 1H NMR (free base; 300 MHz, CDCl3) d
.
1.20–1.40 (m, 3H), 1.60–1.80 (m, 4H), 1.95–2.10 (m,
2H), 2.70–2.80 (m, 4H), 2.90–2.95 (m, 2H), 3.02 (t,
J = 8.1 Hz, 2H), 3.23 (t, J = 8.4 Hz, 2H), 3.75 (s, 2H),
4.13 (t, J = 8.1 Hz, 2H), 7.37 (dt, J = 8.0, 1.2 Hz, 1H),
7.53 (dt, J = 7.5, 1.2 Hz, 1H), 7.62 (dd, J = 7.5, 1.2 Hz,
1H), 7.66 (s, 1H), 7.71 (s, 1H), 7.80 (dd, J = 8.0,
1.2 Hz, 1H). Anal. Calcd for C26H29N3O4ÆHClÆH2O: C,
62.21; H, 6.43; N, 8.37. Found: C, 62.42; H, 6.54; N,
8.36.
1
1493, 1383, 754 cmÀ1. H NMR (free base; 200 MHz,
CDCl3) d 1.20–1.40 (m, 3H), 1.60–2.10 (m, 6H), 2.71
(t, J = 7.8 Hz, 2H), 2.80–3.10 (m, 6H), 3.22 (t,
J = 8.4 Hz, 2H), 3.49 (s, 2H), 4.13 (t, J = 8.4 Hz, 2H),
7.40 (t, J = 7.8 Hz, 1H), 7.50–7.65 (m, 3H), 7.67 (s,
1H), 7.71 (s, 1H). Anal. Calcd for C27H29N3O2ÆHClÆ0.5-
H2O: C, 68.56; H, 6.61; N, 8.88. Found: C, 68.68; H,
6.80; N, 8.91.
5.1.40. 8-{3-[1-(3-Nitrobenzyl)piperidin-4-yl]propanoyl}-
1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-one hy-
drochloride (9o). 99%, Mp 214–216 ꢁC (EtOH–Et2O).
5.2. AChE inhibition activity
AChE activity was measured by an acetylthiocholine
method using human-erythrocyte-derived AChE. 30 lL
of 80 mM Tris–HCl (pH 7.4), 50 lL of AChE solution
(0.2 IU/mL), 50 lL of 5 mM 5,5-dithio-bis(2-nitrobenz-
oic acid), 20 lL of drug solution, and 50 lL of 4 mM
acetylthiocholine iodide were added to the microplate
wells. Absorbance at 412 nM was read every 30 s for
10 min using a microplate reader (Spectra rainbow ther-
mo, Tecan, Switzerland) followed by the calculation of
the reaction velocities using analysis software (Biolise
2.01). The IC50 value and 95% confidence interval of
each drug was calculated by least-squares regression
analysis.
1
IR (KBr) 2924, 1669, 1525, 1491, 731 cmÀ1. H NMR
(free base; 200 MHz, CDCl3) d 1.26–1.44 (m, 3H),
1.62–1.83 (m, 4H), 1.86–2.12 (m, 2H), 2.72 (t,
J = 7.6 Hz, 2H), 2.80–3.12 (m, 6H), 3.23 (t, J = 8.5 Hz,
2H), 3.57 (s, 2H), 4.13 (t, J = 8.5 Hz, 2H), 7.48 (dd,
J = 8.0, 7.8 Hz, 1H), 7.64–7.76 (m, 3H), 8.10 (t,
J = 8.0 Hz, 2H), 8.19 (s, 1H). Anal. Calcd for
C26H29N3O4ÆHClÆ0.5H2O: C, 63.34; H, 6.34; N, 8.52.
Found: C, 63.05; H, 6.40; N, 8.32.
5.1.41. 8-{3-[1-(4-Nitrobenzyl)piperidin-4-yl]propanoyl}-
1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-one hy-
drochloride (9p). 78%, Mp 230–232 ꢁC (EtOH–Et2O).
1
IR (KBr) 2920, 1670, 1518, 1491, 735 cmÀ1. H NMR
5.2.1. AUC200 in Guinea pigs. Male 5-week old Hartley
Guinea pigs were used. The animals were anesthetized
with an intraperitoneal injection of urethane (1.2 g/kg).
The urinary bladder was exposed through an incision
in the abdomen, and the urethra was ligated. A needle
(20-gauge) connected to a polyethylene tube (PE-100)
was inserted into the bladder dome to record intravesical
pressure using a pressure transducer (AP461G, Nihon
koden, Tokyo). Pressure signals were recorded via mul-
tiple unit data acquisition system (MP-100A-CE, Biopac
systems, Santa Barbara, CA, USA) by a personal com-
puter at a sampling rate of 5 Hz. Warmed physiological
saline (38 ꢁC) was injected until regular isovolumetric
bladder contractions appeared. Drugs were adminis-
tered intravenously after confirming stable rhythmic
contractions. The effects of the drugs were estimated
by the area under the curve of the vesical contractions
about 5 min after the drug-administration. AUC200
value was calculated for each compound as the dose
increasing the AUC to twice the pre-drug AUC.
(free base; 200 MHz, CDCl3) d 1.26–1.43 (m, 3H), 1.64–
1.78 (m, 4H), 1.92–2.08 (m, 2H), 2.72 (t, J = 7.9 Hz,
2H), 2.77–3.06 (m, 6H), 3.23 (t, J = 8.5 Hz, 2H), 3.57 (s,
2H), 4.14 (t, J = 8.3 Hz, 2H), 7.50 (d, J = 8.8 Hz, 2H),
7.69 (d, J = 8.8 Hz, 2H), 8.15 (s, 1H), 8.19 (s, 1H). Anal.
Calcd for C26H29N3O4ÆHClÆ0.5H2O: C, 63.34; H, 6.34; N,
8.52. Found: C, 63.66; H, 6.33; N, 8.52.
5.1.42. 2-({4-[3-Oxo-3-(4-oxo-1,2,5,6-tetrahydro-4H-pyr-
rolo[3,2,1-ij]quinolin-8-yl)propyl]piperidin-1-yl}methyl)-
benzonitrile hydrochloride (9q). 84%, Amorphous. IR
(KBr) 2291, 1668, 1596, 1156 cmÀ1. 1H NMR (free base;
200 MHz, CDCl3) d 1.21–1.45 (m, 3H), 1.61–1.83 (m,
4H), 1.99–2.18 (m, 2H), 2.72 (t, J = 7.8 Hz, 2H), 2.82–
3.07 (m, 6H), 3.23 (t, J = 8.4 Hz, 2H), 3.67 (s, 2H),
4.13 (t, J = 8.4 Hz, 2H), 7.26–7.40 (m, 1H), 7.49–7.68
(m, 4H), 7.71 (s, 1H). Anal. Calcd for C27H29N3O2ÆH-
ClÆ2.5H2O: C, 63.71; H, 6.73; N, 8.25. Found: C,
64.00; H, 6.54; N, 8.23.
5.1.43. 3-({4-[3-Oxo-3-(4-oxo-1,2,5,6-tetrahydro-4H-pyr-
rolo[3,2,1-ij]quinolin-8-yl)propyl]piperidin-1-yl}methyl)-
benzonitrile hydrochloride (9r). 76%, Amorphous. IR
(KBr) 2926, 2627, 2232, 1667, 1597, 1493, 1383, 1159,
5.2.2. AUC200 in rats. Male Sprague–Dawley rats
weighing 210–250 g were anesthetized with an intraperi-
toneal injection of urethane (1.2 g/kg). A lower abdomi-
nal midline incision was made to expose the bladder,
and two 23-gauge needles connected to a polyethylene
tube (PE-50) were inserted into the bladder dome, for
recording the intravesical pressure and for intravesical
infusion of physiological saline at the rate of 0.1 mL/
754 cmÀ1 1H NMR (free base; 200 MHz, CDCl3) d
.
1.20–1.40 (m, 3H), 1.60–2.10 (m, 6H), 2.71 (t,
J = 7.8 Hz, 2H), 2.80–2.90 (m, 4H), 3.02 (t, J = 7.8 Hz,
2H), 3.22 (t, J = 8.4 Hz, 2H), 3.51 (s, 2H), 4.13 (t,

Y. Ishichi et al. / Bioorg. Med. Chem. 13 (2005) 1901–1911
1911
Froes-Ferrao, M. M.; Rozental, R.; Aronstam, R. S.;
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min, respectively. After confirming successive micturi-
tion reflexes induced by intravesical infusion of physio-
logical saline, the urethra was ligated not to leak the
urine. The bladder was completely drained off, and infu-
sion was then restarted. Bladder filling was continued
until micturition was observed, and the AUC of the vesi-
cal contractions induced by micturition reflex versus
time were calculated. The post-drug values of the
AUC were measured 30 min after the intraduodenal
drug administration. The ratio of the change of the
AUC after the drug administration, and AUC200 value
was calculated as for the Guinea pig study.
6. (a) Ishihara, Y.; Goto, G.; Miyamoto, M. Curr. Med.
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8. para-Nitrobenzyloxycarbonyl group is sufficiently stable
toward electrophilic species such as acyl cations, owing to
the electron-withdrawing nitro group, and is easily
removed by catalytic hydrogenation. Thus, the selective
deprotection is feasible without effecting the protecting
groups of the heterocyclic moieties (i.e., N-acetyl, N-
formyl, and N-trifluoroacetyl groups).
Acknowledgements
We thank Mr. Koji Ohnishi and Mr. Masashi Yamagu-
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