Synthesis, SAR studies, and evaluation of 1,4-benzoxazepine derivatives as selective 5-HT1A receptor agonists with neuroprotective effect: Discovery of Piclozotan

Article abstract of DOI:10.1016/j.bmc.2005.10.046

A new series of 1,4-benzoxazepine derivatives was designed, synthesized, and evaluated for binding to 5-HT_1A receptor and cerebral anti-ischemic effect. A lot of compounds exhibited nanomolar affinity for 5-HT_1A receptor with good selectivity over both dopamine D ₂ and α₁-adrenergic receptors. Among these compounds, 3-chloro-4-[4-[4-(2-pyridinyl)-1,2,3,6-tetrahydropyridin-1-yl]butyl]- 1, 4-benzoxazepin-5(4H)-one (50: SUN N4057 (Piclozotan) as 2HCl salt) showed remarkable neuroprotective activity in a transient middle cerebral artery occlusion (t-MCAO) model.

Full text of DOI:10.1016/j.bmc.2005.10.046

Bioorganic & Medicinal Chemistry 14 (2006) 1978–1992
Synthesis, SAR studies, and evaluation of
1,4-benzoxazepine derivatives as selective 5-HT1A receptor
agonists with neuroprotective effect: Discovery of Piclozotan
Katsuhide Kamei,* Noriko Maeda, Kayoko Nomura, Makoto Shibata,
Ryoko Katsuragi-Ogino, Makoto Koyama, Mika Nakajima, Teruyoshi Inoue,
Tomochika Ohno and Toshio Tatsuoka
Daiichi Asubio Pharma Co., Ltd, 1-1-1, Wakayamadai, Shimamoto-cho, Mishima-gun, Osaka 618-8513, Japan
Received 1 September 2005; revised 25 October 2005; accepted 25 October 2005
Available online 14 November 2005
Abstract—A new series of 1,4-benzoxazepine derivatives was designed, synthesized, and evaluated for binding to 5-HT1A receptor
and cerebral anti-ischemic effect. A lot of compounds exhibited nanomolar affinity for 5-HT1A receptor with good selectivity over
both dopamine D2 and a1-adrenergic receptors. Among these compounds, 3-chloro-4-[4-[4-(2-pyridinyl)-1,2,3,6-tetrahydropyridin-
1-yl]butyl]-1, 4-benzoxazepin-5(4H)-one (50: SUN N4057 (Piclozotan) as 2HCl salt) showed remarkable neuroprotective activity in
a transient middle cerebral artery occlusion (t-MCAO) model.
Ó 2005 Elsevier Ltd. All rights reserved.
1. Introduction
ing 1,4-benzoxazepine scaffold.15,16 In this issue, we have
provided a full account of design, synthesis, SAR, and
biological evaluation of 1,4-benzoxazepine derivatives
in detail.
Serotonin (5-HT) and its receptors are known to play
important roles in various physiological and pathophys-
iological processes.1,2 Of these receptors, the 5-HT1A
receptor subtype is generally accepted to be involved
in psychiatric disorders such as depression,3 anxiety,4
and psychosis.5 In the past decade, cerebral serotonergic
neuron has been suggested to be involved in cerebral
ischemic conditions. It has been reported that 5-HT1A
receptor agonists have protective effects in cerebral
ischemic conditions,6–11 due to hyperpolarization of cell
membrane12 and glutamate release inhibition.13 At the
present day, acute ischemic stroke is one of the major
causes of death in advanced nations. Though many
pharmacological treatments by means of so-called neu-
roprotective drugs have been tried, they have not been
successful to improve clinical outcome in patients.14
Our goal is to develop a 5-HT1A receptor agonist for a
therapeutic agent against ischemic stroke. We have al-
ready reported novel 5-HT1A receptor agonists possess-
2. Chemistry
2.1. Design
Buspirone, tandospirone, and ipsapirone are well recog-
nized as 5-HT1A receptor agonists (Fig. 1), and the
former two compounds have been useful in treatment
of anxiety and depression.17,18 However, three com-
pounds show a poor selectivity for 5-HT1A receptor;
that is to say buspirone and tandospirone exhibit affinity
for dopamine D2 receptor and ipsapirone does show
affinity for a1-adrenergic receptor (Table 1). It has been
said that dopamine D2 antagonists might cause undesir-
able side effects such as prolactin stimulation19 and
extrapyramidal symptoms,20 and a1-adrenergic receptor
antagonists cause hypotensive effect and worsen clinical
state. We have aspired after a selective 5-HT1A receptor
agonist over both dopamine D2 and a1-adrenergic recep-
tors. We have considered that a selectivity for 5-HT1A
receptor over both dopamine D2 and a1-adrenergic
receptors is attributable to the difference of lipophilic
Keywords: 1,4-benzoxazepine; 5-HT1A; Neuroprotective; Anti-ische-
mia; Piclozotan; SUN N4057.
*
Corresponding author. Tel.: +81 75 962 8194; fax: +81 75 962
6448; e-mail: katsuhide_kamei@asubio.co.jp
0968-0896/$ - see front matter Ó 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2005.10.046

K. Kamei et al. / Bioorg. Med. Chem. 14 (2006) 1978–1992
1979
subsequent amination with 1-PP. Methylene analogue
1b of 1,4-benzoxazepine derivative 1a was prepared
from dicarboxylic acid 4. Methyl 3-(2-methoxycarbon-
yl)phenylpropionate 5 which was prepared from 4 with
H2SO4 in MeOH was converted to monoamide 6. Cycli-
zation of 6 with NaH gave 2-benzazepine-1,3-dione 7 in
88% yield. Other imide intermediates 8–10 were pre-
pared by the same procedure described for the synthesis
of imide derivatives 3 or 7. Compounds 7–10 were N-al-
kylated with 1-bromo-4-chlorobutane or 1,4-dibromo-
butane and subsequently substituted by 1-PP by the
same way as 1a in moderate yield (respectively, 61–
82%, 52–89%).
Amide analogues 1f and 1g and 1,3-benzoxazine deriva-
tives 1h and 1i were prepared by the pathway shown in
Scheme 2. Synthesis of each scaffold was described as
follows. 3,4-Dihydro-1,4-benzoxazepin-5(2H)-one 15,
which is a 3-decarbonyl analogue of imide derivative
1a, was synthesized by the Schmidt rearrangement of
4-chromanone 14 with sodium azide in methanesulfonic
acid. Though 1,5-benzoxazepine isomer 16 was generat-
ed in 2.6% yield, it was separated off by column
chromatography with SiO2. 4,5-Dihydro-1,4-benzoxaze-
pin-3(2H)-one 19, which is a 5-decarbonyl analogue of
imide derivative 1a, was obtained from 2-methoxyben-
zylamine 17. Treatment by demethylation of 17 with
48% aqueous HBr gave aminoalcohol derivative 18.
Selective N-acylation of 18 and cyclization in the pres-
ence of K2CO3 gave amide derivative 19. 2,2-Dimeth-
yl-2,3-dihydro-1,3-benzoxazin-4-one 21 was obtained
by acetal formation of 2 with 2,2-dimethoxypropane in
the presence of p-TsOH. Compounds 1f–i were prepared
from 15 and 19–21 by N-alkylation with 1,4-dibromobu-
tane and subsequent substitution by 1-PP.
Figure 1.
O
Me
N
O
O
Figure 2. Structure of 4-methyl-1,4-benzoxazepin-3,5-dione.
moiety, i.e., imide structure. Buspirone and tandospi-
rone possess aliphatic and steric volume imide moiety
and show an affinity for dopamine D2 receptor. On
the contrary, ipsapirone possesses planar aromatic imide
moiety and shows an affinity for a1-adrenergic receptor.
To reduce affinities for both dopamine D2 and a1-adren-
ergic receptors, we have designed some compounds pos-
sessing benzazepine scaffold which have an aromatic
ring and a little steric volume imide moiety based on
puckered conformation for 7-membered ring (Fig. 2).21
In addition to imide compounds, some vinyl-amide
compounds have been designed because vinyl-carbon
is sp2 carbon as the same imide carbonyl-one. We have
also challenged a transformation of amine part, because
1-(2-pyrimidinyl)piperazine (1-PP), which is a major
metabolite of buspirone, tandospirone, and ipsapirone,
exhibits blood-pressure fall22 and it might worsen clini-
cal states.
A preparation of 1,4-benzoxazepin-5(4H)-one deriva-
tives 28–30 is shown in Scheme 3. 3-Methyl-1,4-ben-
zoxazepin-5(4H)-one scaffold 23 was obtained by
O-alkylation of 2 with chloroacetone and subsequent
cyclization with p-TsOH. 3-Unsubstituted-1,4-ben-
zoxazepin-5(4H)-one scaffold 25 was also synthesized
by O-alkylation of salicylamide 2 with bromoacetalde-
hyde diethyl acetal and the subsequent cyclization
with HCl gas and dehydration of alcohol compound
24 with MsCl. Compounds 28 and 29 were obtained
by the same method as 1a. Synthesis of 3-chloro-1,4-
benzoxazepin-5(4H)-one scaffold 30 was described as
follows. Imide compound 26 was converted to a vinyl
chloride analogue 27 with POCl3 in the presence of
HCl gas in 54% yield. Replacement of terminal chlo-
ride of 27 by 1-PP gave 30.
New pyrimidine derivatives 34, 36, and 38–40 and
pyridine analogues 43–45 were prepared by the path-
way shown in Scheme 4. Tin-lithium exchange of 32,
which was converted from 2-chloropyrimidine 31 by
treatment with n-Bu3SnLi at ꢀ78 °C ,23 and subse-
quent alkylation with N-Boc-4-piperidone gave alcohol
product 33. Dehydration of 33 with POCl3 converted
1,2,3,6-tetrahydropyridine derivative 35, and then
hydrogenation of 35 in the presence of Pd/C gave
37. Pyrimidine derivatives 34, 36, and 38 were
2.2. Synthesis
4-Benzazepine-3,5-dione derivatives 1a–e were prepared
using the pathway shown in Scheme 1. 1,4-Benzoxaza-
pine-3,5-dione scaffold 3 was synthesized by O-alkyl-
ation of salicylamide 2 with ethyl 2-bromoacetate in
the presence of K2CO3 followed by cyclization with
NaOEt in excellent yield. Compound 1a was obtained
by N-alkylation of 3 with 1-bromo-4-chlorobutane and

1980
K. Kamei et al. / Bioorg. Med. Chem. 14 (2006) 1978–1992
Scheme 1. Reagents: (a) BrCH2CO2Et, K2CO3, acetone; (b) NaOEt, DMF; (c) NaH, Br(CH2)4Cl, DMF; (d) 1-PP, NaI, K2CO3, CH3CN;
(e) cH2SO4, MeOH, (f) NH3aq, NH4Cl, 1,4-dioxane; (g) i—NaH, 1,4-dioxane; ii—citric acid; (h) 1-PP, 1,4-dioxane; (i) NaH, Br(CH2)4Br, DMF.
Scheme 2. Reagents: (a) NaN3, CH3SO3H; (b) NaH, Br(CH2)4Br, DMF; (c) 1-PP, Et3N, CH3CN; (d) HBr, H2O; (e) ClCOCH2Cl, K2CO3, CH2C12;
(f) K2CO3, acetone; (g) 1-PP, 1,4-dioxane; (h) 1-PP, NaI, Et3N, DMF; (i) (H3C)2C(OCH3)2, p-TsOH, PhH.
obtained by deprotection of the corresponding Boc
derivatives 33, 35, and 37 with TFA in 83–96% yield.
Regio-isomers 39 and 40 of compounds 36 and 38
were synthesized the same way as described above
from N-Boc-3-piperidone instead of N-Boc-4-piperi-
done. Pyridine derivatives 43–45 were prepared from
2-bromopyridine 41 via alcohol intermediate 42. As-
sessed compounds 30 and 46–54 were obtained by
substitution of chlorobutyl compound 27 with the cor-
responding amines (Scheme 5). Later during our
study, we successfully made an improvement in the
synthesis of 50, which was synthesized by reduction
with NaBH4 of the quaternary ammonium intermedi-
ate 55 in 97% yield.
3. Result and discussion
3.1. In vitro binding assay
Compounds were evaluated for their binding affinities to
5-HT1A, dopamine D2, and a1-adrenergic receptors by
radioligand binding assays (Tables 1, 2). The specific
ligands and tissue sources were used as follows;

K. Kamei et al. / Bioorg. Med. Chem. 14 (2006) 1978–1992
1981
Scheme 3. Reagents: (a) C1CH2COCH3, K2CO3, acetone; (b) p-TsOH, PhCH3; (c) K2CO3, Br(CH2)4Br, acetone; (d) 1-PP, K2CO3, 1,4-dioxane; (e)
BrCH2CH(OEt)2, K2CO3, acetone; (f) HC1, 1,4-dioxane; (g) MsCl, Et3N, CH2C12; (h) K2CO3, Br(CH2)4Cl, acetone; (i) POC13, HC1, 1,4-dioxane;
(j) 1-PP, Nal, Et3N, DMF.
Scheme 4. Reagents and conditions: (a) n-Bu3SnLi, THF, ꢀ78 °C to rt; (b) n-BuLi, THF, ꢀ78 °C; (c) N-Boc-4-piperidone, THF, ꢀ78 °C to rt;
(d) TFA, CH2C12; (e) POC13, pyridine; (f) H2, 10% Pd/C, EtOH; (g) N-Boc-3-piperidone, THF, ꢀ78 °C to rt.
Scheme 5. Reagents: (a) amine (HNRR0), NaI, Et3N, DMF; (b) 2,40-dipyridyl, NaI, CH3CN; (c) NaBH4, EtOH.

1982
K. Kamei et al. / Bioorg. Med. Chem. 14 (2006) 1978–1992
Table 1. Structure and their receptor binding data
Compound
R
IC50 (nM)
D2
IC50 ratio
5-HT1A
3.75
a1
D2/5-HT1A
3866
a1/5-HT1A
1ab
1bc
1cc
14500
N.T.a
N.T.a
850
227
58.4
15.1
398
909
—
—
6.8
60
1dc
1ec
67.3
270
N.T.a
N.T.a
510
—
—
7.6
5.7
1550
1fd
1ge
1hb
1if
52.2
101
N.T.a
N.T.a
N.T.a
N.T.a
4510
3270
580
—
—
—
—
86
32
24
53
23.8
20.8
1100
Buspirone
Tandspirone
Ipsapirone
11.0
7.7
55
2920
2780
457
5.0
8.0
65
265
362
79
59
5.8
371
a Not tested.
b Dihydrochloride.
c Maleinate.
d Trihydrochloride.
e Hydrochloride.
f Fumarate.
(a) 5-HT1A serotonergic receptor:24 [3H]8-OH-DPAT (8-
hydroxy-2-(N,N-di-n-propylamino)tetralin), rat hippo-
campus membranes; (b) dopamine D2 receptor:25
[3H]Raclopride, rat striatum membranes; (c) a1-adrener-
gic receptor:26 [3H]prazosin, rat cerebral cortex
membranes.
All benzazepine derivatives 1a–e showed affinity for 5-
HT1A receptor. Among these analogues, 1,4-benzoxaze-
pine 1a displayed higher 5-HT1A receptor affinity and
better selectivity over both dopamine D2 and a1-adren-
ergic receptors than buspirone, tandospirone, and ipsa-
pirone being up to our expectations. We have also

K. Kamei et al. / Bioorg. Med. Chem. 14 (2006) 1978–1992
Table 2. Structure and their receptor binding data
1983
Compound
X
Amine
IC50 (nM)
D2
IC50 ratio
5-HT1A
10.2
a1
D2/5-HT
—
a1/5-HT1A
1A
28b
29b
30b
46b
47c
48c
49c
50d
51c
52c
53b
54b
Me
H
N.T.a
N.T.a
199
1100
108
—
18.0
1.59
0.77
2650
2790
1.38
0.47
5.81
1.03
79.6
314
N.T.a
—
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
544
43
125
66
342
55
51
N.T.a
N.T.a
494
9560
4340
924
—
3.6
—
1.6
358
179
310
222
11
670
84
128
272
344
146
1800
229
2000
150
893
384
4.8
N.T.a
N.T.a
—
—
a Not tested.
b Fumarate.
c Hydrochloride.
d Dihydrochloride.
confirmed the advantage of imide moiety and 7-mem-
bered scaffold as compared with amide compounds (1a
vs 1f and 1g) and 6-membered analogues (1a vs 1h and
1i). 3-Substituted-1,4-benzoxazepine-5(4H)-one deriva-
tives 28–30 also exhibited binding affinity for 5-HT1A
receptor. Especially vinylchloride derivative 30 showed
emphasized affinity for 5-HT1A receptor with 100-fold
selectivity over both dopamine D2 and a1-adrenergic
receptors. As imide derivative 1a and vinylchloride com-
pound 30 showed similar binding affinities for 5-HT1A
and a1-adrenergic receptors, we have considered that
vinylchloride-amide moiety is a good bioisostere for
imide conformer. 3-Chloro-1,4-benzoxazepin-5(4H)-
one scaffold also showed a puckered conformation for
7-membered ring. Though steric conformation of 30
does not necessarily correspond to 1a, steric volume of
both sides is very similar (Fig. 3).
Next, we investigated effects of various amine moieties.
Pyridine derivatives enhanced affinities for not only 5-
HT1A receptor but also dopamine D2 and a1-adrenergic
receptors as compared with pyrimidinyl derivatives (30

1984
K. Kamei et al. / Bioorg. Med. Chem. 14 (2006) 1978–1992
O
O
Me
Me
N
N
O
Cl
O
O
Figure 3. Structure of 4-methyl-1,4-benzoxazepin-3,5-dione and 3-chloro-4-methyl-1,4-benzoxazepin-5-one.
vs 46, 49 vs 50, and 51 vs 52). Alcohol derivatives 47 and
48 showed a very weak affinity for 5-HT1A receptor.
1,2,3,6-Tetrahydropyridine derivatives 49 and 50 exhib-
ited strong affinity for 5-HT1A receptor and good selec-
tivity over both dopamine D2 and a1-adrenergic
receptors. Piperidine analogues 51 and 52 slightly weak-
en affinity for 5-HT1A receptor compared with pipera-
zine derivatives 30, 46 and tetrahydropyridine
derivatives 49, 50. A slight difference of angle between
basic amine and aromatic plane could pave the way
for better selectivities for 5-HT1A over both dopamine
D2 and a1-adrenergic receptors. Regio-isomers 53 and
54 of pyrimidine derivatives 49 and 51 showed reduced
affinity for 5-HT1A receptor. As a whole 3-chloro-4-[4-
[4-(2-pyridinyl)-1,2,3,6-tetrahydropyridin-1-yl]butyl]-
1,4-benzoxazepin-5(4H)-one 50 exhibited remarkable
affinity for 5-HT1A receptor and moderate selectivity
over both dopamine D2 and a1-adrenergic receptors.
Table 3. Neuronal protective effects of compounds against ischemic
brain damage in the rat t-MCAO model
Compound
% inhibition
1 mg/kg
0.3 mg/kg
1a
30
33
29
46
49
68**
65**
63**
22
42*
16
32*
50
52
Buspirone
53
See experimental section for details.
* P < 0.05 versus vehicle (one-way ANOVA followed by Dunnestꢀs
multiple comparisons test).
** P < 0.01.
mia to above 38.5 °C, but tested compounds reduced
the ischemic hyperthermia at the neuroprotective doses.
It has been reported that 5-HT1A receptor agonists pos-
sess a hypothermic effect.33 We have investigated a
hypothermic effect in this t-MCAO model. 4-Dimethyla-
minoantipyrine, an antipyretic drug, at a dose of
200 mg/kg ip immediately after t-MCAO did not affect
PTBBS levels by only 21% inhibition, although it caused
hypothermia to the same degree as each 5-HT1A recep-
tor agonist (1 mg/kg sc). These results indicate that
pharmacological effects in addition to the hypothermic
effect are involved in the mechanism of neuroprotective
effect of 5-HT1A receptor agonist.
3.2. In vitro 5-HT1A receptor agonist activity
It is known that 5-HT1A receptor agonists inhibit aden-
ylate cyclase activity via Gi protein conjugated with 5-
HT1A receptor.27 Adenylate cyclase activity was deter-
mined according to the modified method of De Vivo
et al.27 The amount of cAMP produced was measured
by a radioimmunoassay. Compound 50 inhibited for-
skolin-stimulated adenylate cyclase activity in plasma
membrane prepared from the rat hippocampus
(IC50 = 2.67 0.74 nM), and this effect was perfectly
blocked by the treatment with WAY-100635,28 which
is a selective 5-HT1A receptor antagonist. These results
indicated that compound 50 acted as a 5-HT1A receptor
agonist at postsynaptic receptors in rat hippocampal
membranes.
It has been considered that a 5-HT1A receptor agonist
hyperpolarizes the cell membrane as well as inhibits glu-
tamic acid release in the hippocampus. So it is thought
that during ischemia 5-HT1A receptor agonists inhibit
excessive excitation of the cell membrane and the release
of glutamic acid.12,13
3.3. In vivo neuroprotective assay
We investigated in vivo neuroprotective effect of 1,4-
benzoxazepine derivatives and buspirone in a rat model
of transient focal cerebral ischemia (Table 3). Male Wis-
tar rats were subjected to t-MCAO using the intralumi-
nal suture method of Koizumi et al.29 The evaluated
compounds and vehicle (saline) were administered
immediately after the occlusion. The measurement of
peripheral type benzodiazepine binding sites (PTBBS)
in ipsilateral cortical and striatal homogenates was car-
ried out as an index for quantification of neuronal dam-
age 10 days after recirculation.30,31 All compounds
caused reduction of the increase in PTBBS levels at a
dose of 1 mg/kg sc.32 Among these compounds, 46, 49,
and 50 exhibited a highly potent anti-ischemic effect
(>60% inhibition; **p < 0.01 vs vehicle). In this model,
rectal temperature was found to increase during ische-
4. Conclusion
We presented the synthesis and biological evaluation of
a novel class of 1,4-benzoxazepine derivatives. 3-Chloro-
1,4-benzoxazepin-5(4H)-one derivatives showed not
only highly potent affinity for 5-HT1A receptor but good
selectivity over dopamine D2 and a1-adrenergic recep-
tors. Since compound 50 was a potent and selective 5-
HT1A receptor agonist compared with buspirone and
showed a desirable neuroprotective effect in the in vivo
t-MCAO model, we have selected it as a clinical candi-
date. Now compound 50 (SUN N4057 (Piclozotan) as
2HCl salt) is currently being developed for treatment
of acute phase of cerebral infarction at phase IIb in clin-
ical trial.

K. Kamei et al. / Bioorg. Med. Chem. 14 (2006) 1978–1992
1985
5. Experimental
6.7 mmol), and K2CO3 (1.5 g, 11.2 mmol) in 50 mL
CH3CN was heated at reflux overnight. The reaction
mixture was concentrated in vacuo, and then the residue
was dissolved into AcOEt and water. An organic layer
was washed with brine and dried over MgSO4. Removal
of the solvent in vacuo gave a residue, which was chro-
matographed over SiO2 using CH2Cl2/MeOH (30:1) as
an eluent to give the title compound (2.0 g, 91%). This
compound was subsequently converted to its dihydro-
chloride. White solid; mp 145–147 °C (recryst solvent:
5.1. General
Melting points were measured with a Yanagimoto or
Buchi 535 melting point apparatus and are uncorrected.
¨
1H NMR spectra were recorded on a Bruker ARX-400
using TMS as an internal reference. IR spectra were
recorded on a Perkin-Elmer 1640 instrument. Mass
spectra were obtained on a JEOL JMX-AX500 by the
FAB ionization method. All compounds were routinely
checked by TLC using Merck Kieselgel 60 F254 plates
(detection at 254 nm). Column chromatography separa-
tions were carried out on Merck Kieselgel 60. Elemental
analyses were performed on a Perkin-Elmer 240B
elemental analyzer.
1
MeOH–Et2O). H NMR (DMSO-d6) d 1.52–1.70 (m,
4H), 2.52–2.73 (m, 6H), 3.82–4.07 (m, 6H), 4.76 (s,
2H), 6.51 (t, 1H, J = 5 Hz), 7.10 (d, 1H, J = 8 Hz),
7.25 (t, 1H, J = 8 Hz), 7.52 (t, 1H, J = 8 Hz), 8.16 (d,
1H, J = 8 Hz), 8.31 (d, 2H, J = 5 Hz); IR (KBr) cmꢀ1
:
2900, 2750, 1700, 1640, 1580, 1480, 1440; Anal. Calcd
for C21H25N5O3Æ2HClÆ 1/2H2O : C, 52.83; H, 5.91; N,
14.67. Found: C, 52.70; H, 5.73; N, 14.78.
5.2. Chemistry
5.2.1. 1,4-Benzoxazepine-3,5(2H, 4H)-dione (3). A mix-
ture of salicylamide 2 (13.7 g, 0.10 mol), K2CO3
(15.2 g, 0.11 mol), and ethyl bromoacetate (11.1 mL,
0.10 mol) in 300 mL acetone was heated at reflux for 4
h. The reaction mixture was cooled down to room tem-
perature, and then the insoluble solid was removed by
filtration. The filtrate was concentrated in vacuo, and
then the given residue was washed with Et2O to give
2-(ethoxycarbonylmethyloxy)benzamide (20.5 g, 92%).
5.2.3. 4,5-Dihydro-2H-benzazepine-1,3-dione (7). A mix-
ture of 3-ortho(hydroxycarbonyl)phenylpropionic acid
(2.0 g, 10.3 mmol) and five drops of conc. sulfuric acid
in 10 mL MeOH was heated at reflux for 30 min. The
reaction mixture was diluted with AcOEt and washed
with brine. After being dried over MgSO4, removal of
the solvent gave 5 (2.2 g, 97%).
A mixture of 5 (4.36 g, 20.0 mmol), NH4Cl (2.0 g,
38.1 mmol), and 120 mL of 28% aqueous NH3 in
120 mL of 1,4-dioxane was stirred for 3 weeks. After
the reaction mixture was concentrated in vacuo, the res-
idue was dissolved into CH2Cl2 and washed with brine.
After being dried over MgSO4, removal of the solvent in
vacuo gave a residue, which was chromatographed over
SiO2 using CH2Cl2/MeOH (97:3) as an eluent to give 6
(1.1 g, 27%).
To a stirred solution of 2-(ethoxycarbonylmethyl-
oxy)benzamide (20.5 g, 92 mmol) in 200 mL DMF was
added dropwise a solution of 28% sodium methoxide
of MeOH (19 mL) at 0 °C. The resultant reaction mix-
ture was stirred at room temperature for 3 h. An aque-
ous solution of 150 mL citric acid hydrate (21 g,
0.10 mol) was added to the reaction mixture at 0 °C,
and then stirring was continued for 2 h. The precipitate
was collected by filtration, washed with diisopropyle-
ther, and dried to give the title compound (16.1 g,
To a stirred solution of 6 (1.1 g, 5.3 mmol) in 60 mL of
1,4-dioxane was added 60% dispersion of NaH on min-
eral oil (271 mg, 6.4 mmol) at 0 °C. The reaction mixture
was stirred at 100 °C for 10 min and poured into an
aqueous solution of citric acid at 0 °C, and then the
aqueous mixtures were extracted with Et2O. The extract
was washed with brine and dried over MgSO4. Removal
of the solvent in vacuo gave the title compound (866 mg,
88%). White solid; mp 103–105 °C. 1H NMR (CDCl3) d
2.88–2.92 (m, 2H), 3.09–3.13 (m, 2H), 7.23 (d, 1H,
J = 7 Hz), 7.42 (t, 1H, J = 8 Hz), 7.52 (ddd, 1H,
J = 1 Hz, 7 Hz, 8 Hz), 8.12 (dd, 1H, J = 1 Hz, 8 Hz);
IR (CHCl3) cmꢀ1: 3180, 3070, 2880, 1700, 1660, 1595,
1450, 1370; FAB-MS m/z: 176 (M+H)+.
1
99%). White solid; mp 144–145 °C. H NMR (CDCl3)
d 4.72 (s, 2H), 7.15 (d, 1H, J = 8 Hz), 7.29 (t, 1H,
J = 8 Hz), 7.56 (t, 1H, J = 8 Hz), 8.14 (d, 1H,
J = 8 Hz), 8.36 (br s, 1H); IR (CHCl3) cmꢀ1: 3222,
3005, 2887, 1722, 1706, 1634, 1588, 1480, 1460; FAB-
MS m/z: 178 (M+H)+.
5.2.2. 4-[4-[4-(2-Pyrimidinyl)piperazin-1-yl]butyl]-1,4-ben-
zoxazepine-3,5(2H,4H)-dione (1a). To a stirred solution
of 3 (10.0 g, 0.056 mol) and 1-bromo-4-chlorobutane
(10.6 g, 0.062 mol) in 100 mL DMF was added 60%
dispersion of NaH on mineral oil (2.71 g, 0.067 mol) at
0 °C. After 1 h, the reaction mixture was poured into
an aqueous solution of citric acid at 0 °C, and then the
products were extracted with Et2O. The extract was
washed with brine and dried over MgSO4. Removal
of the solvent in vacuo gave a residue, which was chro-
matographed over SiO2 using n-hexane/EtOAc (6:1) as
an eluent to give 4-(4-chlorobutyl)-1,4-benzoxazepine-
3,5(2H,4H)-dione (12.6 g, 84%).
5.2.4.
2-[4-[4-(2-Pyrimidinyl)piperazin-1-yl]butyl]-4,5-
dihydro-2H-benzazepine-1,3-dione (1b). The title com-
pound was prepared from 7, using a method similar to
that described for 1a, in 53% yield (in two steps). This
compound was subsequently converted to its maleinate.
White solid; mp 137-140 °C (recryst solvent: MeOH–
1
Et2O). H NMR (DMSO-d6) d 1.53–1.73 (m, 4H), 2.43
(t, 2H, J = 8 Hz), 2.50 (t, 4H, J = 5Hz), 2.99 (s, 4H),
3.83 (t, 4H, J = 5 Hz), 4.03 (t, 2H, J = 8 Hz), 6.47
(t, 1H, J = 5 Hz), 7.16 (d, 1H, J = 7 Hz), 7.36 (t, 1H,
J = 7 Hz), 7.44 (dt, 1H, J = 1, 7 Hz), 7.96 (dd, 1H,
A mixture of 4-(4-chlorobutyl)-1,4-benzoxazepine-
3,5(2H,4H)-dione (1.5 g, 5.6 mmol), sodium iodide
(1.3 g, 8.4 mmol), 1-(2-pyrimidinyl)piperazine (1.1 g,

1986
K. Kamei et al. / Bioorg. Med. Chem. 14 (2006) 1978–1992
J = 1, 7 Hz), 8.29 (d, 2H, J = 5 Hz); IR (KBr) cmꢀ1
:
5.2.9.
4-[4-[4-(2-Pyrimidinyl)piperazin-1-yl]butyl]-1,2-
2940, 2800, 1695, 1640, 1580, 1540, 1490, 1445; Anal.
Calcd for C22H27N5O2 Æ C4H4O4: C, 61.28; H, 6.13; N,
13.75. Found: C, 61.01; H, 6.26; N, 13.64.
dihydro-4H-1,4-benzodiazepine-3,5-dione (1d). The title
compound was prepared from 12, using a method
similar to that described for 1c, in 87% yield. This
compound was subsequently converted to its malei-
nate. White solid; mp 126–133 °C (recryst solvent:
CH2Cl2–Et2O). 1H NMR (DMSO-d6) d 1.47–1.72
(m, 4H), 2.38 (t, 2H, J = 7 Hz), 2.45 (t, 4H,
J = 5 Hz), 3.80 (t, 4H, J = 5 Hz), 3.91 (d, 2H,
J = 5 Hz), 3.94 (t, 2H, J = 7 Hz), 4.78 (t, 1H,
J = 5 Hz), 6.46 (t, 1H, J = 5 Hz), 6.78 (t, 1H,
J = 9 Hz), 6.94 (t, 1H, J = 9 Hz), 7.34 (dt, 1H, J = 2,
9 Hz), 8.27 (dd, 1H, J = 2, 9 Hz), 8.33 (d, 2H,
J = 5 Hz); IR (KBr) cmꢀ1: 3250, 2850, 1690, 1630,
1580, 1540, 1480, 1440; Anal. Calcd for
C21H26N6O2 Æ C4H4O4Æ1H2O: C, 56.81; H, 6.10; N,
15.90. Found: C, 56.82; H, 5.96; N, 15.76.
5.2.5. 4-(4-Bromobutyl)-1,4-benzothiazepine-3,5(2H,4H)-
dione (11). The title compound was prepared from 8,34
using a method similar to that described for the above
4-(4-chlorobutyl)-1,4-benzoxazepine-3,5(2H, 4H)-dione,
1
in 61% yield. Colorless oil. H NMR (CDCl3) d 1.75–
1.96 (m, 4H), 3.43 (t, 2H, J = 6 Hz), 3.68 (s, 2H), 4.03
(t, 2H, J = 6 Hz), 7.31 (m, 3H), 8.17 (m, 1H); IR
(KBr) cmꢀ1: 2950, 2860, 1690, 1630, 1580, 1430; HRMS:
Calcd for C13H14BrNO2S: 326.9927. Found: 326.9921.
5.2.6. 4-(4-Bromobutyl)-1,2-dihydro-4H-1,4-benzodiaze-
pine-3,5-dione (12). The title compound was prepared
from 9, using a method similar to that described
for the above 4-(4-chlorobutyl)-1,4-benzoxazepine-
3,5(2H, 4H)-dione, in 64% yield. Colorless solid; mp
60–61 °C. 1H NMR (CDCl3) d 1.77-1.93 (m, 4H),
3.40 (t, 2H, J = 7 Hz), 3.92 (d, 2H, J = 5 Hz), 3.93
(t, 2H, J = 7 Hz), 4.77 (t, 1H, J = 5 Hz), 6.79 (d,
1H, J = 7 Hz), 6.95 (t, 1H, J = 7 Hz), 7.35 (dt, 1H,
J = 1, 7 Hz), 8.25 (dd, 1H, J = 1, 7 Hz); IR (KBr)
cmꢀ1: 3300, 2850, 1690, 1630, 1600, 1480, 1420;
HRMS: Calcd for C13H15BrN2O2: 310.0316. Found:
310.0312.
5.2.10. 1-Methyl-4-[4-[4-(2-pyrimidinyl)piperazin-1-yl]bu-
tyl]-1,2-dihydro-4H-1,4-benzodiazepine-3,5-dione (1e).
The title compound was prepared from 13, using a
method similar to that described for 1c, in 89% yield.
This compound was subsequently converted to its
maleinate. White solid; mp 160-162 °C (recryst
solvent: CH2Cl2–Et2O). 1H NMR (DMSO-d6)
d
1.53–1.73 (m, 4H), 2.17 (s, 3H), 2.37 (t, 2H,
J = 8 Hz), 2.45 (t, 4H, J = 5 Hz), 3.22 (s, 2H), 3.80
(t, 4H, J = 5 Hz), 3.91 (t, 2H, J = 8 Hz), 6.48 (t,
1H, J = 5 Hz), 6.93 (d, 1H, J = 9 Hz), 6.95 (t, 1H,
J = 9 Hz), 7.44 (dt, 1H, J = 1, 9 Hz), 8.29 (d, 2H,
J = 5 Hz), 8.32 (dd, 1H, J = 1, 9 Hz); IR (KBr)
cmꢀ1: 2920, 2760, 1675, 1635, 1580, 1540, 1495,
1440; Anal. Calcd for C22H28N6O2ÆC4H4O4Æ1/4H2O:
C, 59.02; H, 6.19; N, 15.89. Found: C, 59.04; H,
6.19; N, 15.85.
5.2.7. 4-(4-Bromobutyl)-1-methyl-1,2-dihydro-4H-1,4-
benzodiazepine-3,5-dione (13). The title compound was
prepared from 10, using a method similar to that de-
scribed for the above 4-(4-chlorobutyl)- 1,4-benzoxaze-
1
pine-3,5(2H, 4H)-dione, in 82% yield. Colorless oil. H
NMR (CDCl3) d 1.74–1.96 (m, 4H), 3.22 (s, 3H), 3.41
(t, 2H, J = 6 Hz), 3.86 (s, 2H), 3.92 (t, 2H, J = 6 Hz),
6.94 (d, 1H, J = 8 Hz), 6.96 (t, 1H, J = 8 Hz), 7.45 (dt,
1H, J = 1, 8 Hz), 8.32 (dd, 1H, J = 1, 8 Hz); IR (CHCl3)
cmꢀ1: 2950, 2880, 1700, 1640, 1600, 1500, 1435; HRMS:
Calcd for C14H17BrN2O2: 324.0473. Found: 324.0487.
5.2.11. 4-[4-[4-(2-Pyrimidinyl)piperazin-1-yl]butyl]-1,2-
dihydro-4H-1,4-benzoxazepin-5-one (1f). The title com-
pound was prepared from 15, using a method similar
to that described for 1a, in 35% yield (in two steps). This
compound was subsequently converted to its trihydro-
chloride. White solid; mp 171-172 °C (recryst solvent:
EtOH-Et2O). 1H NMR (DMSO-d6) d 1.63–1.71 (m,
4H), 2.47 (t, 2H, J = 7 Hz), 2.52–2.55 (m, 4H), 3.50 (t,
2H, J = 5 Hz), 3.65 (t, 2H, J = 7 Hz), 3.83–3.87 (m,
4H), 4.37 (t, 2H, J = 5 Hz), 6.48 (t, 1H, J = 5 Hz), 6.99
(d, 1H, J = 8 Hz), 7.16 (t, 1H, J = 8 Hz), 7.38 (dt, 1H,
J = 2, 8 Hz), 7.79 (dd, 1H, J = 2, 8 Hz), 8.30 (d, 2H,
J = 5 Hz); IR (KBr) cmꢀ1: 2930, 2850, 2800, 1630,
1585, 1540, 1470, 1445; Anal. Calcd for
C21H27N5O2 Æ 3HCl: C, 51.38; H, 6.16; N, 14.27. Found:
C, 51.28; H, 6.18; N, 13.91.
5.2.8.
4-[4-[4-(2-Pyrimidinyl)piperazin-1-yl]butyl]-1,4-
benzothiazepine-3,5(2H,4H)-dione (1c). A mixture of
11 (53.8 mg, 0.16 mmol) and 1-(2-pyrimidinyl)pipera-
zine (84.3 mg, 0.49 mmol) in 10 mL of 1,4-dioxane
was heated at reflux for 6 h. The reaction mixture
was concentrated in vacuo, and then the residue was
dissolved into CH2Cl2 and water. An organic layer
was washed with brine and dried over MgSO4.
Removal of the solvent in vacuo gave a residue, which
was chromatographed over SiO2 using n-hexane/
EtOAc (1:3) as an eluent to give the title compound
(35.2 mg, 52%). This compound was subsequently con-
verted to its maleinate. White solid; mp 153–154 °C
(recryst solvent: CH2Cl2–Et2O). 1H NMR (DMSO-
d6) d 1.54–1.72 (m, 4H), 2.40 (t, 2H, J = 8 Hz), 2.47
(t, 4H, J = 5 Hz), 3.68 (s, 2H), 3.81 (t, 4H,
J = 5 Hz), 4.03 (t, 2H, J = 8 Hz), 6.47 (t, 1H,
J = 5 Hz), 7.27–7.49 (m, 3H), 8.17–8.20 (m, 1H); IR
(KBr) cmꢀ1: 2930, 2800, 1730, 1690, 1655, 1635,
1580, 1540, 1490, 1440; Anal. Calcd for C21H25N5O2-
S Æ C4H4O4: C, 56.91; H, 5.54; N, 13.28. Found: C,
56.75; H, 5.56; N, 13.26.
5.2.12. 4,5-Dihydro-1,4-benzoxazepin-3(2H)-one (19). A
mixture of 2-methoxybenzylamine (17) (5.0 g,
0.036 mol) in 50 mL of 48% aqueous hydrobromic acid
was heated at reflux for 3 h. The reaction mixture was
neutralized with 3N NaOH at 0 °C, and then the prod-
uct was extracted with CHCl3 and the extract was
washed with brine. After being dried over MgSO4,
removal of the solvent in vacuo gave 18 (3.78 g, 84%),
which was used for next step without further
purification.

K. Kamei et al. / Bioorg. Med. Chem. 14 (2006) 1978–1992
1987
To a stirred mixture of 18 (3.78 g, 0.031 mol) and
K2CO3 (12.7 g, 0.093 mol) in 50 mL CH2Cl2 was added
dropwise chloroacetyl chloride (2.69 ml, 0.034 mol) at
0 °C. After being stirred for 30 min, the reaction mixture
was diluted with CH2Cl2 and washed with brine. After
being dried over MgSO4, removal of the solvent in vac-
uo gave a residue. A mixture of this residue and K2CO3
(9.25 g, 0.067 mol) in 400 mL acetone was heated at re-
flux for 6 h. The reaction mixture was concentrated in
vacuo, and then a residue was dissolved into CH2Cl2
and water. An organic layer was washed with brine
and dried over MgSO4. Removal of the solvent in vacuo
gave the residue, which was chromatographed over SiO2
using CH2Cl2/MeOH (98:2) as an eluent to give the title
compound (1.28 g, 35%) as a white solid. mp 113–
114 °C (recryst solvent: CH2Cl2–EtOH-Et2O). 1H
NMR (CDCl3) d 4.38 (d, 2H, J = 5 Hz), 4.62 (2H, s),
6.64 (1H, s), 7.11–7.15 (2H, m), 7.21 (dd, 1H, J = 1,
hexane/EtOAc (4:1) as an eluent to give the title com-
pound (1.39 g, 100%) as a white solid. mp 121–124 °C.
1H NMR (CDCl3) d 3.30 (s, 1H), 6.96 (d, 1H,
J = 8 Hz), 7.09 (t, 1H, J = 8 Hz), 7.50 (t, 1H,
J = 8 Hz), 7.77 (d, 1H, J = 8 Hz); IR (CHCl3) cmꢀ1
3064, 1675, 1614, 1469; FAB-MS m/z: 178 (M+H)+.
:
5.2.16. 2,2-Dimethyl-3-[4-[4-(2-pyrimidinyl)piperazin-1-
yl]butyl]-2,3-dihydro1,3-benzoxazin-4-one (1i). The title
compound was prepared from 21, using a method simi-
lar to that described for 1a, in 61% yield (in two steps).
This compound was subsequently converted to its fuma-
rate. White solid; mp 184–185 °C (recryst solvent:
1
MeOH–Et2O). H NMR (DMSO-d6) d 1.45–1.66 (m,
4H), 1.64 (s, 6H), 2.35–2.48 (m, 6H), 3.55–3.67 (m,
2H), 3.70–3.74 (m, 4H), 6.70 (t, 1H, J = 5 Hz), 6.61 (s,
2H), 6.95 (d, 1H, J = 8 Hz) , 7.09 (t, 1H, J = 7 Hz),
7.49 (dt, 1H, J = 1, 8 Hz), 7.76 (dd, 1H, J = 1, 7 Hz),
8.33 (d, 2H, J = 5 Hz); IR (KBr) cmꢀ1: 3596, 2990,
2554, 1718, 1644, 1613, 1586, 1548, 1470; Anal. Calcd
for C22H29N5O2: C, 61.04; H, 6.50; N, 13.69. Found:
C, 60.96; H, 6.51; N, 13.72.
8 Hz), 7.34 (dt, 1H, J = 2, 8 Hz); IR (CHCl3) cmꢀ1
2916, 1671, 1482, 1409; FAB-MS m/z: 164 (M+H)+.
:
5.2.13. 4-[4-[4-(2-Pyrimidinyl)piperazin-1-yl]butyl]-4,5-
dihydro-1,4-benzoxazepin-3(2H)-one (1g). The title com-
pound was prepared from 19, using a method similar to
that described for 1a, in 51% yield (in two steps). This
compound was subsequently converted to its hydrochlo-
ride. White solid; mp 198–199 °C (recryst solvent:
5.2.17. 2-(2-Oxa-n-propyloxy)benzamide (22). To a stir-
red solution of salicylamide 2 (14.6 g, 0.11 mol) in
500 mL of acetone were added K2CO3 (30.0 g,
0.22 mol) and chloroacetone (17 mL, 0.22 mol). The
reaction mixture was heated at reflux for 2 h and then
cooled down to room temperature. After the generated
precipitate was removed by filtration, the filtrate was
concentrated in vacuo and the residue was washed with
Et2O to give the title compound (17.1 g, 83%). Yellow
oil; 1H NMR (CDCl3) d 2.21 (s, 3H), 4.89 (s, 2H),
6.62 (br s, 1H), 6.91 (d, 1H, J = 8 Hz), 7.08 (t, 1H,
J = 8 Hz), 7.46 (t, 1H, J = 8 Hz), 8.12 (d, 1H,
J = 8 Hz), 8.39 (br s, 1H); IR (CHCl3) cmꢀ1: 3088,
1710, 1669, 1587, 1560, 1477, 1446; FAB-MS m/z: 194
(M+H)+.
1
CH2Cl2–Et2O). H NMR (DMSO-d6) d 1.54–1.70 (m,
4H), 2.47–2.54 (m, 6H), 3.58 (t, 2H, J = 7 Hz), 3.84–
3.95 (m, 4H), 4.51 (s, 2H), 4.70 (s, 2H), 6.50 (t, 1H,
J = 5 Hz), 7.03–7.09 (m, 2H), 7.17 (d, 1H, J = 7 Hz),
7.29 (t, 1H, J = 7 Hz), 8.31 (d, 2H, J = 5 Hz); IR
(KBr) cmꢀ1: 2930, 2850, 2800, 1665, 1635, 1590, 1545,
1490, 1445; Anal. Calcd for C21H27N5O2 Æ 1HCl Æ 1H2O:
C, 57.85; H, 6.94; N, 16.07. Found: C, 57.58; H, 6.49; N,
16.04.
5.2.14. 3-[4-[4-(2-Pyrimidinyl)piperazin-1-yl]butyl]-1,3-
3H-benzoxazine-2,4-dione (1h). The title compound
was prepared from 1,3-benzoxazine-2,4-dione 20, using
a method similar to that described for 1a, in 19% yield
(in two steps). This compound was subsequently con-
verted to its dihydrochloride. White solid; mp 206–
208 °C (recryst solvent: MeOH–CHCl3–Et2O). 1H
NMR (DMSO-d6) d 1.63–1.84 (m, 4H), 2.94–3.19 (m,
4H), 3.30–3.42 (m, 2H), 3.57 (t, 2H, J = 5 Hz), 3.93 (t,
2H, J = 5 Hz), 4.64–4.74 (m, 2H), 6.75 (t,
1H, J = 5 Hz), 7.42 (d, 1H, J = 8 Hz) , 7.44 (t, 1H,
J = 8 Hz), 7.81 (t, 1H, J = 8 Hz), 8.00 (d, 1H,
J = 8 Hz), 8.44 (d, 2H, J = 5 Hz), 10.42–10.56 (m, 2H);
IR (KBr) cmꢀ1: 3476, 2717, 1754, 1688, 1621, 1540,
1489, 1433, 1404; Anal. Calcd for C20H23N5O3 Æ 2HCl Æ
2H2O: C, 48.99; H, 5.96; N, 14.28. Found: C, 48.91;
H, 5.81; N, 14.67.
5.2.18. 3-Methyl-1,4-benzoxazepin-5(4H)-one (23). A
mixture of 22 (17.1 g, 88 mmol) and p-toluenesulfonic
acid monohydrate (220 mg, 1.2 mmol) in 100 mL tolu-
ene was heated at reflux overnight with removal of the
generated water with a Dean–Stark trap. The reaction
mixture was diluted with EtOAc, washed with water
and brine, and dried over MgSO4. Removal of the
solvent in vacuo gave a residue, which was chromato-
graphed over SiO2 using hexane/EtOAc (5:1) as an
eluent to give the title compound (12.4 g, 80%).
1
Colorless oil; H NMR (CDCl3) d 1.81 (s, 3H), 6.56 (s,
1H), 6.77 (br s, 1H), 6.89 (d, 1H, J = 8 Hz), 7.10 (t,
1H, J = 8 Hz), 7.34 (t, 1H, J = 8 Hz), 7.89 (d, 1H,
J = 8 Hz); IR (CHCl3) cmꢀ1: 2998, 1684, 1652, 1451;
FAB-MS m/z: 176 (M+H)+.
5.2.15. 2,2-Dimethyl-2,3-dihydro1-1,3-benzoxazin-4-one
(21). A mixture of salicylamide 2 (1.08 g, 7.88 mmol),
2,2-dimethoxypropane (1.94 mL, 15.76 mmol), and p-
TsOH (20 mg, 0.10 mmol) in 30 mL benzene was heated
at reflux for 3 h. The reaction mixture was washed with
saturated aqueous NaHCO3 and brine. After being
dried over MgSO4, removal of the solvent in vacuo gave
a residue, which was chromatographed over SiO2 using
5.2.19. 3-Methyl-4-[4-[4-(2-pyrimidinyl)piperazin-1-yl]bu-
tyl]-1,4-benzoxazepin-5(4H)-one (28). The title com-
pound was prepared from 23, using a method similar
to that described for 1a, in 66% yield (in two steps). This
compound was subsequently converted to its fumarate.
White solid; mp 141–142 °C (recryst solvent: MeOH–
1
Et2O). H NMR (DMSO-d6) d 1.50–1.76 (m, 4H), 1.81
(s, 3H), 2.38 (t, 2H, J = 7 Hz), 2.43 (t, 4H, J = 5 Hz),

1988
K. Kamei et al. / Bioorg. Med. Chem. 14 (2006) 1978–1992
3.71–3.78 (m, 6H), 6.55–6.60 (m, 2H), 6.61 (s, 2H),
7.05 (d, 1H, J = 8 Hz), 7.23 (t, 1H, J = 8 Hz), 7.48 (t,
1H, J = 8 Hz), 7.69 (d, 1H, J = 8 Hz), 8.33 (d, 2H,
J = 5 Hz); IR (KBr) cmꢀ1: 3438, 2956, 1684, 1634,
1584, 1482; Anal. Calcd for C26H31N5O6: C, 61.28; H,
6.13; N, 13.74. Found: C, 61.02; H, 6.22; N, 13.69.
was subsequently converted to its fumarate. mp 152–
154 °C (recryst solvent: MeOH–Et2O). Anal. Calcd for
C25H29N5O6: C, 60.60; H, 5.90; N, 14.13. Found: C,
60.45; H, 6.01; N, 14.01.
5.2.23. 3-Chloro-4-(4-chlorobutyl)-1,4-benzoxazepin-5(4H)-
one (27). A mixture of 3 (5.0 g, 28 mmol), K2CO3 (7.8 g,
56 mmol), and 1-bromo-4-chlorobutane (6.5 mL,
56 mmol) in 100 mL acetone was heated at reflux for 8
h. The reaction mixture was cooled down to room tem-
perature, and then the insoluble solid was removed off
by filtration. The filtrate was concentrated in vacuo,
and then the resultant residue was dissolved into
50 mL of phosphorus oxychloride. A solution of 4 N
HCl in dioxane (30 mL) was added dropwise, and then
the resultant reaction mixture was stirred at 90 °C for
24 h. After the remaining phosphorus oxychloride was
removed in vacuo, the residue was basified to pH 8 by
addition of 10% NaOH solution at 0 °C and extracted
with CH2Cl2. The extract was washed with brine and
dried over MgSO4. Removal of the solvent in vacuo
gave a residue, which was chromatographed over SiO2
using hexane/EtOAc (6:1) as an eluent to give the title
compound (4.3 g, 54%). Colorless oil; 1H NMR (CDCl3)
d 1.86–1.89 (m, 4H), 3.57–3.60 (m, 2H), 3.94 (t, 2H,
J = 6 Hz), 6.73 (s, 1H), 7.02 (d, 1H, J = 8 Hz), 7.22–
7.26 (m, 1H), 7.43–7.47 (m, 1H), 7.86-7.89 (m, 1H); IR
(NaCl) cmꢀ1: 2956, 1704, 1644, 1605, 1574; FAB-MS
m/z: 287 (M+H)+.
5.2.20. 3-Hydroxy-3,4-dihydro-1,4-benzoxazepin-5(2H)-
one (24). To a stirred solution of salicylamide 2 (5.0 g,
36 mmol) in 100 mL acetone were added K2CO3 (7.5 g,
54 mmol) and 2-bromomethyl-1,3-dioxolane (6.7 g,
40 mmol). The resulting mixture was heated at reflux
for 5 h and then cooled down to room temperature.
After the solid was removed by filtration, the filtrate
was concentrated in vacuo to afford a solid that was
crystallized from EtOAc/n-hexane to give 2-(1,3-dioxo-
lan-2-ylmethyl)benzamide (6.2 g, 79%).
A
mixture of 2-(1,3-dioxolan-2-ylmethyl)benzamide
(6.2 g, 28 mmol) and 10% aqueous HCl (5 mL) in
10 mL of 1,4-dioxane was heated at reflux for 2 h. The
reaction mixture was diluted with water and extracted
with EtOAc, and then the organic layer was washed with
water and brine. After drying over MgSO4, removal of
the solvent in vacuo gave a residue, which was chro-
matographed over SiO2 using CH2Cl2/EtOAc (1:2) as
an eluent to give the title compound (3.6 g, 65%). White
solid; mp 102–103 °C. 1H NMR (CDCl3) d 3.15–3.21 (br
s, 1H), 4.09 (d, 1H, J = 12 Hz), 4.42–4.47 (m, 1H), 4.97–
5.03 (m, 1H), 6.82 (br s, 1H), 6.97 (d, 1H, J = 8 Hz), 7.03
(t, 1H, J = 8 Hz), 7.34 (t, 1H, J = 8 Hz), 7.82 (d, 1H,
J = 8 Hz); IR (KBr) cmꢀ1: 3387, 3290, 3200, 2998,
1661, 1615, 1492; FAB-MS m/z: 180 (M+H)+.
5.2.24. 3-Chloro-4-[4-[4-(2-pyrimidinyl)piperazin-1-yl]-
butyl]-1,4-benzoxazepin-5(4H)-one (30). The title com-
pound was prepared from 27, using a method similar
to that described for 1a, in 89% yield. This compound
was subsequently converted to its fumarate. White solid;
mp 138–140 °C (recryst solvent: EtOH–diisopropyle-
5.2.21. 1,4-Benzoxazepin-5(4H)-one (25). To a stirred
solution of 24 (3.6 g, 18 mmol) in 50 mL CH2Cl2 were
added methanesulfonyl chloride (1.7 mL, 22 mmol)
and triethylamine (7.6 mL, 55 mmol) at 0 °C, and then
stirring was continued for 2 h. The reaction mixture
was diluted with CHCl3 (200 mL) and washed with
0.5 N HCl, a saturated solution of NaHCO3 and brine.
After drying over MgSO4, removal of the solvent in vac-
uo gave a residue, which was chromatographed over
SiO2 using CH2Cl2/EtOAc (1:1) as an eluent to give
1
ther). H NMR (DMSO-d6) d 1.48–1.58 (m, 2H), 1.61–
1.70 (m, 2H), 2.36–2.45 (m, 6H), 3.71 (t, 4H, J = 5
Hz), 3.85 (t, 2H, J = 7 Hz), 6.61 (t, 1H, J = 5 Hz), 6.62
(s, 2H), 7.15 (s, 1H), 7.17 (d, 1H, J = 7 Hz), 7.31–7.37
(m, 1H), 7.56–7.63 (m, 1H), 7.77–7.81 (m, 1H), 8.34
(d, 2H, J = 5 Hz); IR (KBr) cmꢀ1: 3416, 2588, 1657,
1586, 1558, 1479, 1454; FAB-MS m/z: 414 (M+H)+.
Anal. Calcd for C25H28ClN5O6: C, 56.66; H, 5.33; N,
13.21. Found: C, 56.61; H, 5.26; N, 13.23.
1
the title compound (2.8 g, 87%). Yellow oil; H NMR
(CDCl3) d 5.23 (d, 1H, J = 7 Hz), 6.14 (d, 1H,
J = 7 Hz), 6.81 (br s, 1H), 6.93 (d, 1H, J = 8 Hz), 7.04
(t, 1H, J = 8 Hz), 7.35 (t, 1H, J = 8 Hz), 7.91 (d, 1H,
J = 8 Hz); IR (CHCl3) cmꢀ1: 2985, 1688, 1653, 1445;
FAB-MS m/z: 162 (M+H)+.
5.2.25. N-tert-Butoxycarbonyl-4-hydroxy-4-(2-pyrimidi-
nyl)piperidine (33). To a stirred solution of 2-tri-n-butyl-
tinpyrimidine 3223 (4.74 g, 0.013 mol) in 30 mL THF
was added dropwise 12 mL of 1.6 N n-butyllithium in
hexane under nitrogen atmosphere at ꢀ78 °C. After
being stirred for 30 min, a solution of N-Boc-4-piperi-
done (3.06 g, 0.016 mol) in 30 mL THF was added drop-
wise, and the reaction temperature was gradually
brought to room temperature. Ice water was added to
the reaction solution, and extraction was performed by
EtOAc. The extract was washed with brine and dried
over MgSO4. Removal of the solvent in vacuo gave a
residue, which was chromatographed over SiO2 using
hexane/EtOAc (2:1) as an eluent to give the title com-
5.2.22. 4-[4-[4-(2-Pyrimidinyl)piperazin-1-yl]butyl]-1,4-
benzoxazepin-5(4H)-one (29). The title compound was
prepared from 25, using a method similar to that de-
scribed for 1a, in 93% yield (in two steps). Pale yellow
oil; 1H NMR (CDCl3) d 1.57–1.80 (m, 4H), 2.44 (t,
2H, J = 7 Hz), 2.54 (t, 4H, J = 5 Hz), 3.54 (t,
4H, J = 5 Hz), 3.67 (t, 2H, J = 7 Hz), 5.57 (d, 1H,
J = 5 Hz), 6.35 (d, 1H, J = 5 Hz), 6.45 (t, 1H,
J = 5 Hz), 6.75 (d, 1H, J = 8 Hz), 7.06 (t, 1H, J = 8
Hz), 7.23 (t, 1H, J = 8 Hz), 7.69 (d, 1H, J = 8 Hz),
8.18 (d, 2H, J = 5 Hz); IR (neat) cmꢀ1: 2941, 1682,
1651, 1485; FAB-MS m/z: 380 (M+H)+; This compound
1
pound (2.6 g, 61%). Yellow oil; H NMR (CDCl3) d
1.49 (s, 9H), 2.16–2.25 (m, 2H), 3.11–3.32 (m, 4H),
4.02–4.15 (m, 2H), 7.22 (t, 1H, J = 5 Hz), 8.74 (d, 2H,

K. Kamei et al. / Bioorg. Med. Chem. 14 (2006) 1978–1992
1989
J = 5 Hz); IR (CHCl3) cmꢀ1: 3022, 1681, 1561, 1424;
FAB-MS m/z: 280 (M+H)+.
5.2.30. 3-(2-Pyrimidinyl)piperidine (40). The title com-
pound was prepared from 39, using a method similar
to that described for 38. Colorless oil. 1H NMR (CDCl3)
d 1.54–1.59 (m, 2H), 2.05–2.09 (m, 1H), 2.16–2.21 (m,
1H), 2.33–2.35 (m, 2H), 2.74–2.81 (m, 1H), 3.00–3.14
(m, 2H), 7.14 (t, 1H, J = 5 Hz), 8.68 (d, 2H, J = 5 Hz);
IR (CHCl3) cmꢀ1: 2929, 2253, 1466, 1148; FAB-MS
m/z: 164 (M+H)+.
5.2.26. 4-Hydroxy-4-(2-pyrimidinyl)piperidine (34). To a
stirred solution of 33 (380 mg, 1.36 mmol) in 3 mL
CH2Cl2 was added dropwise 2 mL trifluoroacetic acid.
After being stirred for 30 min, the reaction mixture
was concentrated in vacuo, and then an aqueous 10%
NaOH and brine were added and extraction was per-
formed by CHCl3. The organic layer was washed with
brine and dried over MgSO4. Removal of the solvent
in vacuo gave the title compound (202 mg, 83%). Yellow
5.2.31. 3-Chloro-4-[4-[4-(2-pyridinyl)piperazin-1-yl]-butyl]-
1,4-benzoxazepin-5(4H)-one (46). The title compound
was prepared from 27, using a method similar to that
described for 1a, in 41% yield. This compound was
subsequently converted to its fumarate. White solid;
mp 158–161 °C (recryst solvent: EtOH–diisopropyle-
1
oil; H NMR (CDCl3) d 1.58–1.65 (m, 2H), 2.19–2.29
(m, 2H), 2.41 (t, 1H, J = 6 Hz), 2.85–3.30 (m, 4H),
7.21 (t, 1H, J = 5 Hz), 8.75 (d, 2H, J = 5 Hz); IR
(CHCl3) cmꢀ1: 3022, 2956, 1570, 1440; FAB-MS m/z:
180 (M+H)+.
1
ther). H NMR (DMSO-d6) d 1.48–1.58 (m, 2H), 1.62–
1.72 (m, 2H), 2.40 (t, 2H, J = 7 Hz), 2.44–2.50 (m,
4H), 3.47 (t, 4H, J = 5 Hz), 3.85 (t, 2H, J = 7 Hz),
6.60–6.65 (m, 1H), 6.61 (s, 2H), 6.80 (d, 1H, J = 9 Hz),
7.16 (s, 1H), 7.17 (d, 1H, J = 7 Hz), 7.33 (t, 1H,
J = 7 Hz), 7.48–7.63 (m, 2H), 7.77–7.81 (m, 1H), 8.08–
8.11 (m, 1H); IR (KBr) cmꢀ1: 3430, 2949, 1704, 1657,
1594, 1480; Anal. Calcd for C22H25ClN4O2 Æ C4H4O4:
C, 59.03; H, 5.53; N, 10.59. Found: C, 58.70; H, 5.54;
N, 10.50.
5.2.27. 4-(2-Pyrimidinyl)-1,2,3,6-tetrahydropyridine (36).
A mixture of 33 (2.11 g, 7.56 mmol) and phosphorus
oxychloride (1.0 mL, 10.6 mmol) in 30 mL pyridine
was stirred for 15 h. The pyridine was distilled off in vac-
uo, and then an aqueous 10% NaOH was added and
extraction was performed by CHCl3. The extract was
washed with brine and dried over MgSO4. Removal of
the solvent in vacuo gave a residue, which was chro-
matographed over SiO2 using hexane/EtOAc (2:1) as
an eluent to give 35 (1.4 g, 69%) as a colorless oil.
5.2.32. 3-Chloro-4-[4-[4-hydroxy-4-(2-pyrimidinyl)piperi-
din-1-yl]butyl]-1,4-benzoxazepin-5(4H)-one (47). The title
compound was prepared from 27, using a method
similar to that described for 1a, in 29% yield. This com-
pound was subsequently converted to its hydrochloride.
Colorless solid; mp 111–114 °C (recryst solvent: acetone);
1H NMR (DMSO-d6) d 1.80–1.59 (m, 4H), 2.09–1.95 (m,
2H), 2.40–2.26 (m, 2H), 3.29–3.11 (m, 4H), 3.51–3.42 (m,
2H), 3.87 (t, 2H, J = 7 Hz), 7.16 (s, 1H), 7.16 (d, 1H,
J = 8 Hz), 7.35 (t, 1H, J = 8 Hz), 7.46 (t, 1H, J = 5 Hz),
7.60 (t, 1H, J = 7 Hz), 7.79 (d, 1H, J = 8 Hz), 8.85 (d,
2H, J = 5 Hz), 9.55 (br s, 1H) ; IR (KBr) cmꢀ1: 2558,
1646, 1589, 1453, 1305; HRMS: Calcd for C22H26ClN4O3
(M+H)+: 429.1693. Found: 429.1683.
4-(2-Pyrimidinyl)-1,2,3,6-tetrahydropyridine 36 was pre-
pared from 35, using a method similar to that described
for 34, in 96% yield as a colorless oil. 1H NMR (CDCl3)
d 2.62–2.66 (m, 2H), 3.12 (t, 2H, J = 6 Hz), 3.62–3.64
(m, 2H), 7.09 (t, 1H, J = 5 Hz), 7.27–7.29 (m, 2H),
8.68 (d, 2H, J = 5 Hz); IR (CHCl3) cmꢀ1: 2984, 1557,
1423, 1210; FAB-MS m/z: 162 (M+H)+.
5.2.28. 4-(2-Pyrimidinyl)piperidine (38). A mixture of 35
(310 mg, 1.19 mmol) and 100 mg of 10% palladium on
carbon in 10 mL EtOH was stirred under hydrogen
atmosphere for 2 days. The catalyst was filtered out,
the filtrate was concentrated in vacuo, and the residue
was chromatographed over SiO2 using n-hexane/EtOAc
(1:1) as an eluent to give N-tert-butoxycarbonyl-4-(2-
5.2.33. 3-Chloro-4-[4-[4-hydroxy-4-(2-pyridinyl)piperidin-
1-yl]butyl]-1,4-benzoxazepin-5(4H)-one (48). The title
compound was prepared from 27, using a method simi-
lar to that described for 1a, in 84% yield. This com-
pyrimidinyl)piperidine 37 (160 mg, 52%) as
colorless oil.
a
pound
was
subsequently
converted
to
its
hydrochloride. White solid; mp 172–175 °C (recryst sol-
1
4-(2-Pyrimidinyl)piperidine 38 was prepared from 37,
using a method similar to that described for 34, in
95% yield as a colorless oil. H NMR (CDCl3) d 1.76–
1.86 (m, 2H), 2.00–2.04 (m, 2H), 2.75–2.82 (m, 2H),
vent: acetone). H NMR (DMSO-d6) d 1.78–1.82 (m,
6H), 2.43–2.47 (m, 2H), 3.19–3.27 (m, 4H), 3.43–3.45
(m, 2H), 3.87 (t, 2H, J = 7 Hz), 7.16–7.18 (m, 2H),
7.33 (s, 1H), 7.35 (d, 1H, J = 8 Hz), 7.61 (t, 1H,
J = 8 Hz), 7.72 (d, 1H, J = 8 Hz), 7.80 (d, 1H,
J = 8 Hz), 7.92 (m, 1H), 8.56 (d, 1H, J = 5 Hz), 9.64
(br s, 1H); IR (KBr) cmꢀ1: 3425, 2950, 1653, 1605,
1521, 1454; FAB-MS m/z: 428 (M+H)+. Anal. Calcd
for C23H26ClN3O3ÆHCl: C, 59.49; H, 5.86; N, 9.05.
Found: C, 59.73; H, 5.77; N, 8.86.
1
2.99–3.06 (m, 1H), 3.20–3.24 (m, 2H), 7.12 (t, 1H,
J = 5 Hz), 8.68 (d, 2H, J = 5 Hz); IR (CHCl3) cmꢀ1
3017, 1563, 1427, 1228; FAB-MS m/z: 164 (M+H)+.
:
5.2.29. 5-(2-Pyrimidinyl)-1,2,3,6-tetrahydropyridine (39).
The title compound was prepared from 32, using a
method similar to that described for 36. Colorless oil.
1H NMR (CDCl3) d 2.41–2.44 (m, 2H), 3.08 (t, 2H,
J = 6 Hz), 3.95 (2H, s), 7.09 (t, 1H, J = 5 Hz), 7.36–
7.38 (m, 1H), 8.66 (d, 2H, J = 5 Hz); IR (CHCl3)
cmꢀ1: 2952, 1653, 1627, 1424; FAB-MS m/z: 162
(M+H)+.
5.2.34. 3-Chloro-4-[4-[4-(2-pyrimidinyl)-1,2,3,6-tetrahydro-
pyridin-1-yl]butyl]-1,4-benzoxazepin-5(4H)-one (49). The
title compound was prepared from 27, using a method
similar to that described for 1a, in 26% yield. This
compound was subsequently converted to its hydrochlo-

1990
K. Kamei et al. / Bioorg. Med. Chem. 14 (2006) 1978–1992
ride. Colorless solid; mp 147–151 °C (recryst solvent:
pound was subsequently converted to its fumarate. Col-
orless solid; mp 124–126 °C (recryst solvent: acetone). ;
1H NMR (DMSO-d6) d 1.61–1.70 (m, 4H), 2.31–2.40
(m, 2H), 2.59–2.62 (m, 4H), 3.42–3.51 (m, 2H), 3.84–
3.89 (m, 2H), 6.60 (s, 2H), 7.11–7.15 (m, 2H), 7.23 (s,
1H), 7.29–7.34 (m, 2H), 7.58 (t, 1H, J = 7 Hz), 7.78 (d,
1
MeOH/acetone). H NMR (DMSO-d6) d 1.10–1.85 (m,
4H), 2.85–2.99 (m, 2H), 3.24–3.27 (m, 3H), 3.65–3.70
(m, 1H), 3.85–3.88 (m, 3H), 4.09–4.13 (m, 1H), 7.13–
7.14 (m, 3H), 7.33–7.43 (m, 2H), 7.60 (t, 1H,
J = 8 Hz), 7.79 (d, 1H, J = 8 Hz), 8.82 (d, 2H,
J = 5 Hz), 10.15 (br s, 1H) ; IR (KBr) cmꢀ1: 3394,
2930, 1661, 1605, 1453, 1422, 1379, 1200; FAB-MS m/
z: 411 (M+H)+; Anal. Calcd for C22H23ClN4O2ÆH-
Cl Æ 0.5H2O : C, 57.90; H, 5.30; N, 12.28. Found: C,
58.10; H, 5.33; N, 12.29.
1H, J = 8 Hz), 8.73 (d, 2H, J = 5 Hz); IR (KBr) cmꢀ1
:
2926, 2576, 1699, 1649, 1560, 1478, 1422, 1378; HRMS:
Calcd for C22H24ClN4O2 (M+H)+: 411.1588. Found:
411.1583.
5.2.39.
3-Chloro-4-[4-[3-(2-pyrimidinyl)piperidin-1-yl]-
5.2.35. 3-Chloro-4-[4-[4-(2-pyridinyl)-1,2,3,6-tetrahydro-
pyridin-1-yl]butyl]-1,4-benzoxazepin-5(4H)-one (50). The
title compound was prepared from 27, using a method
similar to that described for 1a, in 84% yield. This com-
pound was subsequently converted to its dihydrochlo-
ride. White solid; mp 133–134 °C (recryst solvent: 2-
PrOH-water). 1H NMR (DMSO-d6) d 1.70–1.76 (m,
2H), 1.84–1.86 (m, 2H), 2.91–2.93 (m, 2H), 3.21–3.25
(m, 3H), 3.64–3.67 (m, 1H), 3.84–3.87 (m, 3H), 4.03–
4.08 (m, 1H), 6.74–6.76 (m, 1H), 7.14–7.17 (m, 2H),
7.34 (t, 1H, J = 8 Hz), 7.42–7.44 (m, 1H), 7.60 (t, 1H,
J = 8 Hz), 7.70–7.72 (m, 1H), 7.79 (dd, 1H, J = 2 and
8 Hz), 7.95–7.97 (m, 1H), 8.61–8.63 (m, 1H), 10.74 (br
s, 1H); IR (KBr) cmꢀ1: 3320, 3015, 2600, 1644, 1612,
1513, 1455; FAB-MS m/z: 410 (M+H)+; Anal. Calcd
for C23H24ClN3O2 Æ 2HCl Æ 2H2O: C, 53.24; H, 5.83; N,
8.10. Found: C, 53.56; H, 6.04; N, 7.92.
butyl]-1,4-benzoxazepin-5(4H)-one (54). The title com-
pound was prepared from 27, using a method similar
to that described for 1a, in 41% yield. This compound
was subsequently converted to its fumarate. Amor-
phous; 1H NMR (DMSO-d6) d 1.58–1.95 (m, 8H),
2.21–2.35 (m, 3H), 2.88–3.01 (m, 2H), 3.61–3.65 (m,
2H), 3.82–3.88 (m, 2H), 6.61 (s, 2H), 7.12–7.16 (m,
2H), 7.33–7.38 (m, 2H), 7.50–7.55 (m, 1H), 7.79 (d,
1H, J = 8 Hz), 8.77 (d, 2H, J = 5 Hz); IR (KBr) cmꢀ1
:
2947, 1643, 1558, 1480; Anal. Calcd for C22H26ClN4O2
(M+H)+: 413.1744. Found: 413.1701.
5.2.40. 3-Chloro-4-[4-[4-(2-pyrimidinyl)pyridinio-1-yl]butyl]-
1,4-benzoxazepin-5(4H)-one iodide (55). A mixture of 27
(200 mg, 0.70 mmol), sodium iodide (210 mg,
1.39 mmol), and 2,40-dipyridyl (120 mg, 0.77 mmol) in
2 mL CH3CN was heated at reflux for 30 h. The reaction
mixture was allowed to cool, then the precipitated crystal
was obtained by filtration and was recrystallized from
MeOH/acetone/Et2O to give the title compound
5.2.36.
3-Chloro-4-[4-[4-(2-pyrimidinyl)piperidin-1-yl]-
butyl]-1,4-benzoxazepin-5(4H)-one (51). The title com-
pound was prepared from 27, using a method similar
to that described for 1a, in 84% yield. This compound
was subsequently converted to its hydrochloride. Color-
1
(298 mg, 96%). H NMR (DMSO-d6) d 1.65–1.71 (m,
2H), 2.01–2.12 (m, 2H), 3.87 (t, 2H, J = 7 Hz), 4.71 (t,
2H, J = 7 Hz), 7.10 (s, 1H), 7.14 (d, 1H, J = 8 Hz), 7.33
(t, 1H, J = 8 Hz), 7.58 (dt, 1H, J = 2 Hz, 8 Hz), 7.66 (dd,
1H, J = 4 Hz, 8 Hz), 7.77 (dd, 1H, J = 2 Hz, 8 Hz), 8.11
(dt, 1H, J = 2 Hz, 8 Hz), 8.44 (d, 1H, J = 8 Hz), 8.81 (d,
2H, J = 7 Hz), 8.87 (d, 1H, J = 4 Hz), 9.21 (d, 2H,
J = 7 Hz); IR (KBr) cmꢀ1: 3445, 3008, 1642, 1603, 1561,
1475, 1456; FAB-MS m/z: 406 (M)+.
1
less solid; mp 110–113 °C (recryst solvent: acetone).; H
NMR (DMSO-d6) d 1.66–1.85 (m, 4H), 2.05–2.20 (m,
4H), 3.03–3.15 (m, 5H), 3.54–3.57 (m, 2H), 3.84–3.87
(m, 2H), 7.14–7.17 (m, 2H), 7.33–7.40 (m, 2H), 7.58–
7.62 (m, 1H), 7.80 (d, 1H, J = 8 Hz), 8.78 (d, 2H,
J = 5 Hz), 10.15 (br s, 1H) ; IR (KBr) cmꢀ1: 3051,
2946, 1646, 1604, 1564, 1478, 1456, 1426; HRMS: Calcd
for C22H26ClN4O2 (M+H)+: 413.1744. Found: 413.1726.
5.2.41. Different synthetic method of 50 from 55. To a stir-
red solution of 55 (800 mg, 1.50 mmol) in 20 mL EtOH
was added sodium borohydride (140 mg, 3.00 mmol) at
0 °C, and then the resultant mixture was agitated at
room temperature for 10 min. Water was added and
extraction was performed with EtOAc. An organic layer
was washed with brine and dried over MgSO4. Removal
of the solvent in vacuo gave a residue, which was chro-
matographed over SiO2 using CH2Cl2/MeOH (30:1) as
an eluent to give the title compound (718 mg, 97%).
5.2.37. 3-Chloro-4-[4-[4-(2-pyridinyl)piperidin-1-yl]butyl]-
1,4-benzoxazepin-5(4H)-one (52). The title compound
was prepared from 27, using a method similar to that de-
scribed for 1a, in 85% yield. This compound was subse-
quently converted to its hydrochloride. White solid; mp
158–161 °C (recryst solvent: acetone). 1H NMR
(DMSO-d6) d 1.68–1.89 (m, 4H), 2.04–2.15 (m, 4H),
2.95–3.18 (m, 5H), 3.55–3.58 (m, 2H), 3.84–3.87 (m,
2H), 7.14–7.18 (m, 2H), 7.31–7.40 (m, 3H), 7.60 (t, 1H,
J = 8 Hz), 7.79 (d, 1H, J = 8 Hz), 7.89–7.91 (m, 1H),
5.3. Biological evaluations
8.55–8.59 (m, 1H), 9.71 (br s, 1H); IR (KBr) cmꢀ1
:
3428, 2946, 2672, 1648, 1540, 1454; FAB-MS m/z: 412
(M+H)+; Anal. Calcd for C23H26ClN3O2ÆHCl Æ H 2O: C,
54.93; H, 6.01; N, 8.36. Found: C, 54.67; H, 5.64; N, 8.18.
5.3.1. Evaluation of affinity with 5-HT1A serotonergic
receptor24. The hippocampi dissected from brains of
male Wistar rats were homogenized in 50 mM Tris-
phosphate buffer (pH 7.7). The homogenate was centri-
fuged at 4 °C and 35,000g for 10 min. The pellet was
suspended in the same buffer, homogenized again, and
incubated at 37 °C for 30 min. This mixture was centri-
fuged at 4 °C and 35,000g for 10 min, and then the same
5.2.38. 3-Chloro-4-[4-[5-(2-pyrimidinyl)-1,2,3,6-tetrahydro-
pyridin-1-yl]butyl]-1,4-benzoxazepin-5(4H)-one (53). The
title compound was prepared from 27, using a method
similar to that described for 1a, in 20% yield. This com-

K. Kamei et al. / Bioorg. Med. Chem. 14 (2006) 1978–1992
1991
buffer was added to the obtained precipitate. This
homogenization-centrifugation operation was repeated
once more to obtain a final precipitate, and then
10 lM N-methyl-N-2-propynylbenzylamine (Pargyline),
4 mM calcium chloride, and 0.1% ascorbic acid con-
tained in a 50 mM Tris-phosphate buffer (pH 7.7) were
added. This was then homogenized to prepare the 5-
HT1A receptor. For the binding assay, 0.4 nM [3H]8-
OH-DPAT was used, various concentrations of test
compounds were added to a system of 0.25 mg/mL pro-
tein or a total of 0.25 mL, and these were incubated at
25 °C for 30 min. A Whatman GF/C filter was used to
filter each of the reaction solutions, then the filter was
washed by 20 mM Tris-phosphate buffer (pH 7.7). The
5-HT1A receptor was trapped on the filter and the radio-
activity of the 8-OH-DPAT bound to it was measured to
find the degree of binding. The 50% of binding affinity
(IC50) was calculated from the degrees of binding in
the various sample concentrations.
Annoura, T. Nishihara, and G. Nakayama for their
encouragement throughout this work.
References and notes
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Acknowledgments
We wish to thank Dr. Y. Hayashi for useful suggestions
for the binding assays. Thanks are also due to Drs. H.
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1992
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that of sham-operated group.
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