Synthesis of 1-benzothiepine and 1-benzazepine derivatives as orally active CCR5 antagonists

Article abstract of DOI:10.1248/cpb.52.254

Quaternary ammonium benzocycloheptene compound 1 has previously been reported as a clinical candidate for an injectable CCR5 antagonist. In order to develop an orally active CCR5 antagonist, derivatives of tertiary amine benzocycloheptene 2, the chemical precursor to 1, were investigated. The benzocycloheptene ring was converted to benzothiepine and benzazepine rings and it was found that these changes could enhance the potency of tertiary amine derivatives. In particular, the 1-benzothiepine-1,1-dioxide 11b and the N-methyl-1-benzazepine 18 showed increased activity and good preliminary pharmacokinetic properties. The synthesis of 1-benzothiepine and 1-benzazepine derivatives and their activity are described.

Full text of DOI:10.1248/cpb.52.254

254
Chem. Pharm. Bull. 52(2) 254—258 (2004)
Vol. 52, No. 2
Synthesis of 1-Benzothiepine and 1-Benzazepine Derivatives as Orally
Active CCR5 Antagonists
Yoshio ARAMAKI,a Masaki SETO,a Tomohiro OKAWA,a Tsuneo ODA,a Naoyuki KANZAKI,b and
a
Mitsuru SHIRAISHI
a Medicinal Chemistry Research Laboratories, Pharmaceutical Research Division, Takeda Chemical Industries, Ltd; and
b Pharmaceutical Discovery Center, Pharmaceutical Research Division, Takeda Chemical Industries, Ltd.; 2–17–85
Jusohonmachi, Yodogawa-ku, Osaka 532–8686, Japan.
Received October 31, 2003; accepted December 3, 2003; published online December 8, 2003
Quaternary ammonium benzocycloheptene compound 1 has previously been reported as a clinical candi-
date for an injectable CCR5 antagonist. In order to develop an orally active CCR5 antagonist, derivatives of ter-
tiary amine benzocycloheptene 2, the chemical precursor to 1, were investigated. The benzocycloheptene ring
was converted to benzothiepine and benzazepine rings and it was found that these changes could enhance the po-
tency of tertiary amine derivatives. In particular, the 1-benzothiepine-1,1-dioxide 11b and the N-methyl-1-ben-
zazepine 18 showed increased activity and good preliminary pharmacokinetic properties. The synthesis of 1-ben-
zothiepine and 1-benzazepine derivatives and their activity are described.
Key words CCR5 antagonist; quaternary ammonium salt; tertiary amine moiety; 1-benzazapine; 1-benzothiepine
The b-chemokine receptor CCR5, a G-protein-coupled precursor of 1, benzocycloheptene derivative 2 containing a
seven-transmembrane domain receptor, has been shown to act tertiary amine moiety, exhibited CCR5 antagonistic activity
as a major co-receptor for fusion and entry of macrophage- with an IC50 value of 0.95 mM in the binding assay. In addi-
tropic (M-tropic or R5) HIV-1 into the host cells.1—4) Al- tion, since 2 exhibited considerably better oral absorption
though combination chemotherapy and Highly Active Anti- than quaternary ammonium derivative 1, 2 was used as a
Retroviral Therapy (HAART) have achieved long-term sup- starting point to develop orally active small molecule CCR5
pression of viral replication in HIV-1-infected individuals,5) antagonists. In order to improve the potency of tertiary amine
CCR5 presents an attractive target for the inhibition of M- derivatives, conversion of the benzocycloheptene ring of lead
tropic HIV-1 replication.
compound 2 to other condensed-heterocycle rings such as 1-
N,N-Dimethyl-N-[4-[[[2-(4-methylphenyl)-6,7-dihydro- benzothiepine and 1-benzazepine was investigated, and the
5H-benzocyclohepten-8-yl]carbonyl]amino]benzyl]tetrahy- synthesis of these derivatives is described.
dro-2H-pyran-4-aminium chloride 1 has previously been re-
ported as a novel and highly potent non-peptide CCR5 antag- Chemistry
onist with a IC50 value of 1.4 nM in the binding assay.6,7)
The synthetic routes to the 1-benzothiepine, 1-benzoth-
Compound 1 has been selected as a clinical candidate for de- iepine-1-oxide and 1-benzothipine-1,1-dioxide derivatives are
velopment as a subcutaneous injectable agent since it exhib- outlined in Chart 1. The benzothiepine ring was constructed
ited poor oral absorption owing to the quaternary ammonium by intramolecular Friedel-Crafts reaction of 4, which was
moiety. However, in the course of the investigation of quater- prepared by the alkylation of p-bromothiophenol 3 with ethyl
nary ammonium derivatives, it was found that the chemical 4-bromobutyrate and subsequent alkaline hydrolysis. The
resulting bromide 5 was condensed with 4-methylphenyl-
boronic acid by Suzuki coupling reaction to give the ketone
6. Subsequent methoxycarbonylation gave the b-keto-ester,
which was reduced using sodium borohydride, and dehy-
drated via mesylation to give the a,b-unsaturated esters 7.
Benzothiepine-1,1-dioxide 8 was obtained by m-chloroper-
Fig. 1
Chart 1
To whom correspondence should be addressed. e-mail: Aramaki_Yoshio@takeda.co.jp
© 2004 Pharmaceutical Society of Japan

February 2004
255
Chart 2
benzoic acid (mCPBA)-oxidation of 7. Alkaline hydrolysis of Table 1.
the esters (7, 8) afforded carboxylic acids (9a, 9b), which
were coupled with 4-[N-methyl-N-(tetrahydropyran-4-yl)-
aminomethyl]aniline 107) to provide the desired products
(11a, 11b). Oxidation of benzothiepine 11a using mCPBA
Compound
X
R
IC50 (mM)a)
gave benzothiepine-1-oxide derivative 11c.
Next, the synthesis of 1-methyl-1-benzazepine derivative
18 was carried out according to Chart 2. 4-{[(Benzyloxy)car-
bonyl]amino}butanoic acid 12 was N-methylated, tert-butyl-
esterified, and deprotected by hydrogenation to give tert-
butyl 4-(methylamino)butanoate 13. The condensation of
ester 13 with 5-bromo-2-fluorobenzaldehyde 14 gave substi-
tuted 2-aminobenzaldehyde 15. The benzazepine ring 16a
was constructed by Dieckmann-type condensation of alde-
hyde 15, using potassium tert-butoxide in good yeild (77%).
Suzuki coupling reaction of 16a with 4-methylphenylboronic
acid gave 16b which was converted to 17 by acid hydrolysis.
Condensation of 17 with aniline 10 gave the desired anilide
18. Further details are to be found in Table 2 and the Experi-
mental Section.
2
20
21
22
23
24
25
19
1
CH2
CH2
O
0.95
2.6
4.0
O
1.6
O
0.63
0.64
0.73
0.53
0.0014
0.0014
O
MeNCHEt2
O
MeN(CH2)3OH
O
CH2
O
26
a) Inhibitory effects on the binding of [125I]-RANTES to CCR5-expressing CHO
cells.
Results and Discussion
The synthesized compounds, benzocycloheptene 2, the
benzoxepine 19, and a variety of tertiary amine derivatives
20—257) were evaluated for their inhibitory effects on
chemokine binding to CCR5-expressing CHO cells. Binding
assays were performed in the presence of [125I]-RANTES and
the results are summarized in Tables 1 and 2 as IC50 values.
The effect of changing the tertiary amine group of lead com-
pound 2 for benzocycloheptene and 1-benzoxepine deriva-
tives is shown in Table 1. Generally, the SAR of the tertiary
amine moiety was similar to those of the corresponding
quaternary ammonium moiety previously reported.7) The
piperidines (20, 21) were less active compared with the
bulkier N-(a-branched alkyl)-N-methylamines (2, 19, 22—
25). The 4-oxocyclohexyl 23 and 3-pentyl 24 derivatives
were comparable to tetrahydropyran-4-yl 19, which was
about twice as active as the benzocycloheptene 2. Since qua-
ternary ammonium compound 1 exhibited similar potency to
the corresponding 1-benzoxepine compound 26 (IC50ϭ1.4
nM),7) differences in the atom at the 5-postion of the benzocy-
cloheptene ring were considered to have little effect on
CCR5 antagonistic activity. However, in contrast, changes in
the atom at the 5-postion of the tertiary amine derivatives,
was found to affect activity.
other changes in the benzocycloheptene ring were investi-
gated (Table 2). Replacement of the benzocycloheptene ring
with the 1-benzothiepine ring 11a slightly increased activity,
and the 1-benzothiepine-1,1-dioxide 11b and the 1-benzoth-
iepine-1-oxide 11c showed 3 to 5-fold more potent activity
(IC50 values: 0.20 and 0.30 mM, respectively). In addition, the
1-benzazepine ring was examined and N-methyl-1-benz-
azepine 18 was found to exhibit more than 10-fold greater
potency (IC50 valueϭ0.13 mM), than benzocycloheptene 2.
The pharmacokinetic parameters were determined for
compounds 2, 11b, and 18 in rats (1 mg/kg, i.v.; 10 mg/kg,
p.o.).8) The AUCs(0—24 h) of compounds 2, 11b and 18 were
1.03, 1.55, and 1.56 mg·h/ml, respectively (10 mg/kg, p.o.),
and the corresponding bioavailabilities were 48%, 52%, and
67%. These results indicate that compounds 11b and 18 pos-
sess good oral bioavailability (Ͼ50%) in rats, similar to that
of compound 2.
The quaternary ammonium compound 1 is a highly potent
CCR5 antagonist. Since the tertiary amine 2 showed ca. 700-
fold less potency, the quaternary ammonium moiety was
considered to be essential for good activity. However, the re-
sults reported herein indicate potency for the tertiary amine
series can be increased by changes in the benzocycloheptene
Therefore, while retaining the tertiary amine moiety of 2,

256
Vol. 52, No. 2
Table 2.
Compound
X
IC50 (mM)a)
mp (°C)
Formula
Anal.b)
11a
11b
11c
18
S
SO2
SO
0.80
0.20
0.30
0.13
234—235
234—235
191—192
178—181
C31H34N2O2S·0.25H2O
C31H34N2O4S
C31H34N2O3S·0.25H2O
C32H37N3O2
C, H, N
C, H, N
C, H, N
C, H, N
NMe
a) Inhibitory effects on the binding of [125I]RANTES to CCR5-expressing CHO cells. b) Analytical results were within 0.4% of the theoretical value.
ring. In particular, 1-benzothiepine-1,1-dioxide 11b and the yield 72%: Yellow oil. 1H-NMR (CDCl3) d: 1.54 (9H, s), 2.38 (3H, s), 2.83
(2H, t, Jϭ4.9 Hz), 3.06 (3H, s), 3.28 (2H, t, Jϭ4.9 Hz), 6.85 (1H, d,
Jϭ8.4 Hz), 7.23 (2H, d, Jϭ8.0 Hz), 7.45 (1H, dd, Jϭ8.6, 2.4 Hz), 7.46 (2H,
d, Jϭ8.2 Hz), 7.53 (1H, d, Jϭ2.2 Hz), 7.67 (1H, s).
Methyl 7-(4-Methylphenyl)-5-oxo-2,3,4,5-tetrahydro-1-benzothiepine-
N-methyl-1-benzazepine 18 were found to have increased ac-
tivity, and exhibited good preliminary pharmacokinetic prop-
erties. Further modifications of 1-benzothiepine-1,1-dioxides
and 1-benzazepines are under investigation to find orally ac-
tive CCR5 antagonists with improved profiles.
4-carboxylate To a solution of 6 (17.9 g, 66.7 mmol) in dimethyl carbon-
ate (300 ml), was added sodium methoxide (18.0 g, 330 mmol), and the mix-
ture was refluxed under nitrogen atmosphere for 8 h. The reaction mixture
was poured into 1 N HCl under ice cooling, and the aqueous mixture was ex-
tracted with EtOAc. The organic layer was washed with water and brine,
dried over MgSO4, and evaporated in vacuo. The residue was washed with
EtOAc and hexane to give 19.8 g (92%) of the title compound as colorless
crystals: mp 109—110 °C. 1H-NMR (CDCl3) d: 2.39 (3H, s), 2.44—2.90
(3H, m), 3.17—3.30 (2H, m), 3.75 (3H, s), 4.56—4.65 (1H, m), 7.25 (2H, d,
Jϭ8.0 Hz), 7.49—7.53 (3H, m), 7.60 (1H, dd, Jϭ8.2, 2.0 Hz), 8.10 (1H, d,
Jϭ2.0 Hz), 8.07 (1H, d, Jϭ1.8 Hz). IR (KBr) cmϪ1: 1748, 1682. Anal. Calcd
for C19H18O3S: C, 69.91; H, 5.56. Found. C, 70.33; H, 5.66.
Experimental
Melting points were obtained with a Yanagimoto micro melting point ap-
paratus and are uncorrected. Proton nuclear magnetic resonance (NMR)
spectra were recorded on a Varian Gemini 200 spectrometer (200 MHz),
with tetramethylsilane as the internal standard. TLC analyses were carried
out on Merck Kieselgel 60 F254 plates. Elemental analyses were carried out
by Takeda Analytical Laboratories, Ltd., and are within Ϯ0.4% of the theo-
retical values unless otherwise noted. Chromatographic purification was car-
ried out on silica gel columns (Kieselgel 60, 0.063—0.200 mm, Merck).
Yields were not optimized.
Methyl 7-(4-Methylphenyl)-2,3-dihydro-1-benzothiepine-4-carboxylate
(7) To a solution of methyl 7-(4-methylphenyl)-5-oxo-2,3,4,5-tetrahydro-
1-benzothiepine-4-carboxylate (13.9 g, 42.6 mmol) in CH2Cl2 (250 ml), was
added a mixture of NaBH4 (2.4 g, 63.4 mmol) in MeOH below Ϫ10 °C, and
the mixture was stirred at Ϫ10 °C for 1 h. The reaction mixture was washed
with water, dried over MgSO4, and evaporated in vacuo. To a solution of the
residue and triethylamine (18.0 ml, 0.13 mol) in CH2Cl2 (250 ml), was added
dropwise methanesulfonyl chloride (7.50 ml, 45.2 mmol) under ice cooling.
After overnight stirring at room temperature, 1,8-diazabicyclo[5.4.0]undec-
7-ene (28.0 ml, 0.187 mol) was added dropwise with ice cooling. The reac-
tion mixture was stirred for 1 h at room temperature, washed with water,
dried over MgSO4, and evaporated in vacuo. The residue was purified by
column chromatography (hexane : EtOAcϭ4 : 1) to give 6.7 g (51%) of 7 as
colorless crystals: mp 108—109 °C. 1H-NMR (CDCl3) d: 2.39 (3H, s), 3.01
(2H, t, Jϭ5.9 Hz), 3.22 (2H, t, Jϭ5.9 Hz), 3.84 (3H, s), 7.26 (2H, d,
Jϭ7.8 Hz), 7.41 (1H, dd, Jϭ8.0, 1.8 Hz), 7.46—7.54 (3H, m), 7.59 (1H, d,
Jϭ1.8 Hz), 7.88 (1H, s). IR (KBr) cmϪ1: 1709. Anal. Calcd for C19H18O2S:
C, 73.52; H, 5.84. Found. C, 73.60; H, 5.63.
4-[(4-Bromophenyl)thio]butanoic Acid (4) A mixture of 3 (125 g,
0.66 mol), ethyl 4-bromobutyrate (135 g, 0.69 mol) and K2CO3 (109 g, 0.79
mol) in DMF (1.2 l) was stirred at room temperature for 2 h. Water was
added, and the aqueous mixture was extracted with EtOAc. The organic
layer was washed with water and brine, dried over MgSO4, and evaporated in
vacuo. To a solution of the residue in EtOH (1.5 l) was added 1 N NaOH
(800 ml), and the mixture was stirred for 3 h. The mixture was concentrated
in vacuo, and the residue was extracted with water. After being washed
with EtOAc, the aqueous layer was acidified using HCl and extracted
with EtOAc. The organic layer was washed with water and brine, dried over
MgSO4, and evaporated in vacuo to give 172 g (96%) of 4 as colorless crys-
1
tals: mp 118—119 °C. H-NMR (CDCl3) d: 1.87—2.02 (2H, m), 2.53 (2H,
t, Jϭ7.1 Hz), 2.96 (2H, t, Jϭ7.2 Hz), 7.21 (2H, d, Jϭ8.8 Hz), 7.41 (2H, d,
Jϭ8.8 Hz). IR (KBr) cmϪ1: 1699. Anal. Calcd for C10H11BrO2S: C, 43.65;
H, 4.03. Found: C, 43.70; H, 3.93.
7-Bromo-3,4-dihydro-1-benzothiepin-5(2H)-one (5) A mixture of 4
(58 g, 0.21 mol) and polyphosphoric acid (830 g) was heated at 110 °C for
1.5 h. The mixture was poured into ice and water, and the aqueous mixture
was extracted with EtOAc. The organic layer was washed with water and
brine, dried over MgSO4, and evaporated in vacuo. The residue was purified
by column chromatography (hexane : EtOAcϭ2 : 1) to give 37.2 g (69%) of
Methyl 7-(4-Methylphenyl)-2,3-dihydro-1-benzothiepine-4-carboxylate
1,1-dioxide (8) To a solution of 7 (1.5 g, 4.8 mmol) in CH2Cl2 (25 ml),
mCPBA (70%, 2.4 g, 9.7 mmol) was added under ice cooling, and the mix-
ture was stirred at room temperature for 1 h. After aqueous Na2S2O3 was
added, the mixture was concentrated in vacuo, and the residue was extracted
with EtOAc. The organic layer was washed with aqueous NaHCO3, water
and brine, dried over MgSO4, and evaporated in vacuo to give 1.6 g (97%) of
1
5 as pale brown crystals: H-NMR (CDCl3) d: 2.22—2.35 (2H, m), 2.94—
3.08 (4H, m), 7.33 (1H, d, Jϭ8.0 Hz), 7.44 (1H, dd, Jϭ8.0, 2.6 Hz), 7.96
(1H, d, Jϭ2.6 Hz). IR (KBr) cmϪ1: 1682. Anal. Calcd for C10H9BrOS: C,
46.71; H, 3.53. Found: C, 46.71; H, 3.45.
1
8 as colorless crystals: mp 203—204 °C. H-NMR (CDCl3) d: 2.43 (3H, s),
7-(4-Methylphenyl)-3,4-dihydro-1-benzothiepin-5(2H)-one (6) A mix-
ture of 5 (17.8 g, 69.2 mmol), 4-methylphenylboronic acid (10.0 g, 73.6
mmol), EtOH (100 ml) and 2 M K2CO3 (100 ml) in toluene (300 ml) was stir-
red at room temperature under argon atmosphere for 30 min. Tetrakis(triph-
enylphosphine)palladium (3.2 g, 2.77 mmol) was added, and the mixture was
refluxed for 3.5 h under argon atmosphere. The organic layer was separated
and the aqueous layer was extracted with EtOAc. The combined organic
layer was washed with water and brine, dried over MgSO4, and evaporated in
vacuo. The residue was purified by column chromatography (hexane :
EtOAcϭ9 : 1) to give 17.9 g (99%) of 6 as colorelss crystals: mp 108—
3.15 (2H, t, Jϭ6.6 Hz), 3.65 (2H, t, Jϭ6.6 Hz), 3.88 (3H, s), 7.31 (2H, d,
Jϭ8.3 Hz), 7.52 (2H, d, Jϭ8.3 Hz), 7.69—7.74 (2H, m), 7.92 (1H, s), 8.22
(1H, d, Jϭ8.8 Hz). IR (KBr) cmϪ1: 1713. Anal. Calcd for C19H18O4S: C,
66.65; H, 5.30. Found. C, 66.47; H, 5.33.
7-(4-Methylphenyl)-2,3-dihydro-1-benzothiepine-4-carboxylic Acid (9a)
A mixture of 7 (2.5 g, 8.1 mmol) and 1 N NaOH (100 ml) in MeOH (200 ml)
and diethylether (100 ml) was stirred overnight at room temperature. The
mixture was concentrated, acidified using 1 N HCl and extracted with EtOAc.
The organic layer was washed with water and brine, dried over MgSO4, and
evaporated in vacuo to give 2.3 g (95%) of 9a as colorless crystals: mp
245—246 °C. 1H-NMR (CDCl3) d: 2.40 (3H, s), 3.05 (2H, t, Jϭ5.4 Hz),
3.24 (2H, t, Jϭ5.4 Hz), 7.26 (2H, d, Jϭ8.0 Hz), 7.41—7.56 (4H, m), 7.62
(1H, d, Jϭ2.0 Hz), 8.01 (1H, s). IR (KBr) cmϪ1: 1680. Anal. Calcd for
C19H16O2S: C, 72.94; H, 5.44. Found. C, 72.71; H, 5.34.
1
109 °C. H-NMR (CDCl3) d: 2.23—2.37 (2H, m), 2.39 (3H, s), 2.98—3.12
(4H, m), 7.24 (2H, d, Jϭ7.0 Hz), 7.48—7.59 (4H, m), 8.07 (1H, d,
Jϭ1.8 Hz). IR (KBr) cmϪ1: 1678. Anal. Calcd for C17H16OS: C, 76.08; H,
6.01. Found: C, 75.78; H, 6.07.
16b: This compound was prepared in a similar manner to that used for 6,
9b: This compound was prepared in a similar manner to that used for 9a,

February 2004
257
yield 92% (purity about 70%); 1H-NMR (CDCl3) d: 2.43 (3H, s), 3.14 (2H,
t, Jϭ6.6 Hz), 3.66 (2H, t, Jϭ6.6 Hz), 7.26—7.33 (2H, m), 7.47—7.57 (2H,
m), 7.70—7.74 (2H, m), 7.95 (1H, s), 8.21 (1H, d, Jϭ8.8 Hz).
quintet, Jϭ7.2 Hz), 2.27 (2H, t, Jϭ7.3 Hz), 2.43 (3H, s), 2.61 (2H, t, Jϭ
7.1 Hz).
tert-Butyl 4-[(4-Bromo-2-formylphenyl)(methyl)amino]butanoate (15)
To a solution of 13 (1.05 g, 6.06 mmol) in DMF (5.0 ml), a solution of 5-
bromo-2-fluorobenzaldehyde (14) (1.03 g, 5.05 mmol) in DMF (1.0 ml) and
K2CO3 (0.84 g, 6.06 mmol) was added. The mixture was stirred at 70 °C for
60 h. Water (50 ml) was added, and the aqueous mixture was extracted with
EtOAc. The organic layer was washed with water and brine, dried over
MgSO4, and evaporated in vacuo. The residue was purified by column chro-
matography (hexane : EtOAcϭ10 : 1) to give 1.62 g (90%) of 15 as a yellow
oil: 1H-NMR (CDCl3) d: 1.42 (9H, s), 1.88 (2H, quintet, Jϭ7.4 Hz), 2.22
(2H, t, Jϭ7.3 Hz), 2.88 (3H, s), 3.14 (2H, t, Jϭ7.3 Hz), 7.01 (1H, d,
Jϭ8.6 Hz), 7.55 (1H, dd, Jϭ8.7, 2.5 Hz), 7.88 (1H, d, Jϭ2.6 Hz), 10.19
(1H, s).
7-(4-Methylphenyl)-N-(4-{[methyl(tetrahydro-2H-pyran-4-yl)amino]-
methyl}phenyl)-2,3-dihydro-1-benzothiepine-4-carboxamide (11a) To a
mixture of 9a (0.3 g, 1.0 mmol) in CH2Cl2 (10 ml), was added oxalyl chlo-
ride (0.27 ml, 2.8 mmol) and DMF (cat. amount) under ice cooling, the mix-
ture was stirred for 2 h at room temperature. The solvent was evaporated in
vacuo. A solution of the residue in THF (15 ml) was added dropwise to a so-
lution of 10 (0.25 g, 1.1 mmol) and triethylamine (0.42 ml, 3.0 mol) in THF
(15 ml) under ice cooling, and the reaction mixture was stirred overnight at
room temperature under nitrogen atmosphere. The solvent was evaporated in
vacuo, and then water was addded. The aqueous mixture was extracted with
EtOAc. The organic layer was washed with water and brine, dried over
MgSO4, and evaporated in vacuo to give 0.45 g (90%) of 11a as colorless
crystals. Recrystallized from EtOAc and hexane: mp 234—235 °C. 1H-NMR
(CDCl3) d: 1.63—1.77 (4H, m), 2.21 (3H, s), 2.40 (3H, s), 2.57—2.70 (1H,
m), 3.08 (2H, t, Jϭ5.8 Hz), 3.26—3.44 (4H, m), 3.57 (2H, s), 4.01—4.11
(2H, m), 7.24—7.34 (3H, m), 7.40—7.57 (8H, m), 7.70 (1H, s). IR (KBr)
cmϪ1: 2949, 2845, 1651, 1597, 1516. Anal. Calcd for C31H34N2O2S·
0.25H2O: C, 74.00; H, 6.91; N, 5.57. Found. C, 73.98; H, 6.86; N, 5.77.
11b: This compound was prepared in a similar manner to that used for
11a, yield 46%, mp 234—235 °C. 1H-NMR (CDCl3) d: 1.67—1.75 (4H, m),
2.21 (3H, s), 2.42 (3H, s), 2.57—2.70 (1H, m), 3.17 (2H, t, Jϭ6.8 Hz), 3.37
(2H, t, Jϭ2.6, 11.2 Hz), 3.58 (2H, s), 3.73 (2H, t, Jϭ6.8 Hz), 4.01—4.11
(2H, m), 7.27—7.36 (4H, m), 7.49—7.57 (4H, m), 7.65 (1H, s), 7.70 (1H,
tert-Butyl 7-Bromo-1-methyl-2,3-dihydro-1H-1-benzazepine-4-carboxy-
late (16a) A mixture of 15 (4.54 g, 12.7 mmol) and potassium tert-butox-
ide (1.43 g, 12.7 mmol) in tert-BuOH (250 ml) was stirred at reflux for 1 h.
The mixture was poured into water, 1 N HCl was added, and the aqueous
mixture was extracted with EtOAc. The organic layer was washed with water
and brine, dried over MgSO4, and evaporated in vacuo. The residue was pu-
rified by column chromatography (hexane : EtOAcϭfrom 10 : 1 to 1 : 1) to
1
give 3.33 g, (77%) of 16 as a yellow oil: H-NMR (CDCl3) d: 1.53 (9H, s),
2.80 (2H, t, Jϭ4.8 Hz), 3.00 (3H, s), 3.21 (2H, t, Jϭ4.7 Hz), 6.65 (1H, d,
Jϭ8.8 Hz), 7.25 (1H, dd, Jϭ8.8, 2.2 Hz), 7.39 (1H, d, Jϭ2.6 Hz), 7.46
(1H, s).
1-Methyl-7-(4-methylphenyl)-2,3-dihydro-1H-1-benzazepine-4-car-
boxylic Acid Hydrochloride (17) A mixture of 16b (490 mg, 1.40 mmol)
and 2 N HCl in EtOAc (14 ml) was stirred at room temperature for 20 h. The
solvent was evaporated in vacuo to give 443 mg (96%) of 17 as pale yellow
crystals: mp 249—252 °C (dec.). 1H-NMR (DMSO-d6) d: 2.32 (3H, s), 2.75
(2H, t, Jϭ4.6 Hz), 3.03 (3H, s), 3.25 (2H, t, Jϭ4.9 Hz), 6.92 (1H, d,
Jϭ8.6 Hz), 7.22 (2H, d, Jϭ8.2 Hz), 7.53 (1H, dd, Jϭ8.8, 2.4 Hz), 7.55 (2H,
d, Jϭ8.2 Hz), 7.65 (1H, d, Jϭ2.4 Hz), 7.68 (1H, s). IR (KBr) cmϪ1: 3021,
2469, 1707, 1466, 1190, 1107, 810, 530. Anal. Calcd for C19H19NO2·
HCl·0.3H2O: C, 68.08; H, 6.19; N, 4.18. Found. C, 67.97; H, 6.13; N, 4.05.
1-Methyl-7-(4-methylphenyl)-N-[4-[[methyl(tetrahydro-2H-pyran-4-
yl)amino]methyl]phenyl]-2,3-dihydro-1H-1-benzazepine-4-carboxamide
(18) Thionyl chloride (0.26 ml, 3.57 mmol) was added to a solution of 17
(386 mg, 1.17 mmol) in DMF (12 ml) at room temperature. The mixture was
stirred at room temperature for 30 min, evaporated in vacuo. A solution
of the residue in CH2Cl2 (10 ml) was added dropwise to a solution of 10
(310 mg, 1.41 mmol) and triethylamine (0.82 ml, 5.88 mmol) in CH2Cl2
(4.0 ml) under ice cooling. The reaction mixture was stirred at room temper-
ature for 22 h. The mixture was poured into water, and the aqueous mixture
was extracted with CH2Cl2. The organic layer was washed with water, dried
over MgSO4, and evaporated in vacuo. The residue was purified by column
chromatography (EtOh : EtOAcϭ1 : 9) to give crystals. Recrystallized from
ethanol to give 250 mg (43%) of 18 as yellow crystals: mp 178—181 °C. 1H-
NMR (CDCl3) d: 1.64—1.76 (4H, m), 2.21 (3H, s), 2.38 (3H, s), 2.66 (1H,
septet, Jϭ5.3 Hz), 2.96 (2H, t, Jϭ4.4 Hz), 3.09 (3H, s), 3.30—3.43 (4H, m),
3.58 (2H, s), 4.01—4.06 (2H, m), 6.88 (1H, d, Jϭ8.6 Hz), 7.23 (2H, d,
Jϭ8.0 Hz), 7.30 (2H, d, Jϭ8.4 Hz), 7.42, (1H, s), 7.46 (2H, d, Jϭ8.2 Hz),
7.47 (1H, dd, Jϭ8.3, 2.3 Hz), 7.535 (2H, d, Jϭ8.4 Hz), 7.539 (1H, d,
Jϭ2.6 Hz), 7.58 (1H, s). IR (KBr) cmϪ1: 3337, 2949, 2851, 1653, 1516,
1501, 1341, 1304, 1238, 818, 521. Anal. Calcd for C32H37N3O2: C, 77.54; H,
7.52; N, 8.48. Found. C, 77.51; H, 7.43; N, 8.44.
dd, Jϭ2.0, 8.2 Hz), 7.94 (1H, s), 8.21 (1H, d, Jϭ8.2 Hz). IR (KBr) cmϪ1
:
2946, 2845, 2845, 1667, 1597, 1518. Anal. Calcd for C31H34N2O4S: C,
70.16; H, 6.46; N, 5.28. Found. C, 69.95; H, 6.22; N, 5.16.
7-(4-Methylphenyl)-N-(4-{[methyl(tetrahydro-2H-pyran-4-yl)amino]-
methyl}phenyl)-2,3-dihydro-1-benzothiepine-4-carboxamide 1-oxide (11c)
To a solution of 11a (0.2 g, 0.4 mmol) in CH2Cl2 (50 ml), mCPBA (70%,
0.1 g, 0.4 mmol) was added below Ϫ10 °C, and the mixture was stirred at
that temperature for 1 h. After aqueous Na2S2O3 was added, the mixture was
concentrated in vacuo, and the residue was extracted with EtOAc. The or-
ganic layer was washed with aqueous NaHCO3, water and brine, dried over
MgSO4, and evaporated in vacuo. The residue was purified by column chro-
matography (10% MeOH/CH2Cl2) to give 0.04 g (18%) of 11c as colorless
crystals. Recrystallized from EtOAc and hexane: mp 191—192 °C. 1H-NMR
(CDCl3) d: 1.65—1.80 (4H, m), 2.22 (3H, s), 2.41 (3H, s), 2.55—290 (2H,
m), 3.10—3.25 (1H, m), 3.35—3.50 (3H, m), 3.58 (2H, s), 3.81—3.95 (1H,
m), 4.01—4.11 (2H, m), 7.25 (2H, d, Jϭ8.0 Hz), 7.33 (2H, d, Jϭ8.5 Hz),
7.45 (2H, d, Jϭ8.0 Hz), 7.52 (1H, s), 7.61 (2H, d, Jϭ8.5 Hz), 7.70 (1H, dd,
Jϭ2.0, 8.2 Hz), 7.97 (1H, d, Jϭ8.0 Hz), 8.26 (1H, s). IR (KBr) cmϪ1: 2948,
2845, 1663, 1599, 1516. Anal. Calcd. for C31H34N2O3S·0.25H2O: C, 71.72;
H, 6.70; N, 5.40. Found. C, 71.79; H, 6.82; N, 5.66.
4-[[(Benzyloxy)carbonyl](methyl)amino]butanoic Acid To a solution
of 12 (25.0 g, 105 mmol) and methyl iodide (37.4 g, 263 mmol) in THF (500
ml) was added sodium hydride (60% dispersion, 10.5 g, 263 mmol) under ice
cooling. The mixture was stirred at room temperature under nitrogen for
24 h and then poured into ice and 1 N NaOH. After being washed with Et2O,
the aqueous layer was acidified using conc. HCl and extracted with EtOAc.
The organic layer was washed with 1 M Na2S2O3, dried over MgSO4, and
evaporated in vacuo to give 26.3 g (quant.) of the title compound as a pale
yellow oil: 1H-NMR (CDCl3) d: 1.88 (2H, m), 2.35—2.37 (2H, m), 2.93
(3H, s), 3.36 (2H, t, Jϭ6.6 Hz), 5.13 (2H, s), 7.35 (5H, s).
Binding Assays CHO-K1 and CHO/CCR5 cells (5ϫ104 cells per
100 ml) were cultured in a microtiter tray. After a 24 h incubation at 37 °C,
the culture medium was replaced with the binding buffer (Ham’s F-12
medium containing 20 mM Hepes and 0.5% bovine serum albumin; pH 7.2).
Binding reactions were performed at room temperature for 40 min in the
presence of [125I]-RANTES (specific activity: 2000 Ci/mmol, Amersham
Pharmacia, Buckinghamshire, U.K.) and various concentration of the test
compound. The binding reaction was terminated by washing out the free lig-
and with cold PBS, and the cell-associated radioactivity was counted by
Top-countTM scintillation counter (Packard Japan, Tokyo, Japan).
tert-Butyl 4-[[(Benzyloxy)carbonyl](methyl)amino]butanoate To
a
mixture of MgSO4 (50.6 g, 420 mmol) in CH2Cl2 (1 l), H2SO4 (6.0 ml,
105 mmol) was added with vigorous stirring. After 15 min, 4-[[(benzyl-
oxy)carbonyl](methyl)amino]butanoic acid (26.3 g, 105 mmol) and tert-
BuOH (50.5 ml, 528 mmol) were added successively. The mixture was
tightly sealed, and stirred for 18 h at room temperature. Aqueous NaHCO3
was added, and the organic layer was washed with brine, dried over MgSO4
and concentrated in vacuo. The residue was purified by column chromatog-
raphy (hexane : EtOAcϭ5 : 1) to give 17.2 g (53%) of title compound as a
colorless oil: 1H-NMR (CDCl3) d: 1.44 (9H, s), 1.82 (2H, quintet, Jϭ6.6
Hz), 2.21 (2H, t, Jϭ6.2 Hz), 2.93 (3H, s), 3.31 (2H, t, Jϭ7.1 Hz), 5.13 (2H,
s), 7.35 (5H, s).
Acknowledgments We thank Mr. Migifumi Ino for pharmacokinetic
tert-Butyl 4-(Methylamino)butanoate (13) A solution of tert-butyl
4-[[(benzyloxy)carbonyl](methyl)amino]butanoate (6.06 g, 19.7 mmol) in
MeOH (70 ml) was hydrogenated over 10% Pd-C (580 mg) for 3 h at room
temperature under atmospheric pressure. The catalyst was removed by filtra-
tion, and the filtrate was evaporated in vacuo to give 3.35 g (98%) of 13 as a
analysis.
References and Notes
1) Feng Y., Broder C. C., Kennedy P. E., Berger E. A., Science, 272,
872—877 (1996).
1
colorless oil. H-NMR (CDCl3) d: 1.45 (9H, s), 1.72 (1H, br s), 1.77 (2H,
2) Alkhatib G., Combadiere C., Broder C. C., Feng Y., Kennedy P. E.,

258
Vol. 52, No. 2
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Y., Shiraishi M., Aramaki Y., Okonogi K., Ogawa Y., Meguro K., Fu-
jino M., Proc. Natl. Acad. Sci. U.S.A., 96, 5698—5703 (1999).
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8) The further details of experimental conditions and data are not shown.