Synthesis and structure-activity relationships of N-(4-amino-2,6-diisopropylphenyl)-N'-(1,4-diarylpiperidine-4-yl)methylureas as anti-hyperlipidemic agents

Article abstract of DOI:10.1016/j.bmc.2009.04.059

Based on 1,4-diarylpiperidine-4-methylureas, a new class of ACAT inhibitors, we examined in the study the SAR of a series of compounds prepared by replacing the substituent at the three aromatic parts. Introduction of long alkoxy group onto the phenyl moi

Full text of DOI:10.1016/j.bmc.2009.04.059

Bioorganic & Medicinal Chemistry 17 (2009) 4636–4646
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com/locate/bmc
Synthesis and structure–activity relationships of N-(4-amino-2,6-diisopropyl-
phenyl)-N’-(1,4-diarylpiperidine-4-yl)methylureas as anti-hyperlipidemic
agents
b,
a
a
a
Shigehiro Asano a, , Hitoshi Ban , Koichi Kino , Katsuhisa Ioriya , Masami Muraoka
*
*
a Dainippon Sumitomo Pharma Co. Ltd, Kasugade Naka 3-1-98, Konohana-ku, Osaka 554-0022, Japan
b Dainippon Sumitomo Pharma Co. Ltd, Enoki 33-94, Suita, Osaka 564-0053, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
Based on 1,4-diarylpiperidine-4-methylureas, a new class of ACAT inhibitors, we examined in the study
the SAR of a series of compounds prepared by replacing the substituent at the three aromatic parts. Intro-
duction of long alkoxy group onto the phenyl moiety at the B-part was effective in improving both the
inhibitory activity for ACAT and the up-regulatory activity for LDL-R expression. Particularly, 3-hydroxy-
propoxy group (43) on the phenyl moiety of B-part led to improved solubility, while keeping both biolog-
ical activities. Compound 43 inhibited ACAT activity with an IC50 value of 18 nM, which is superior to that
of a known ACAT inhibitor, CI-1011. In addition, compound 43 revealed an LDL-R up-regulatory activity
comparable to that of SMP-797. We therefore expect this compound to be a novel ACAT inhibitor.
Ó 2009 Elsevier Ltd. All rights reserved.
Received 18 March 2009
Revised 27 April 2009
Accepted 28 April 2009
Available online 3 May 2009
Keywords:
ACAT inhibitor
LDL receptor up-regulator
1,4-Diarylpiperidine-4-methylureas
Antihyperlipidemic agent
Solubility
1. Introduction
We have previously reported a novel ACAT inhibitor, SMP-797
(Fig. 1), with potent cholesterol-lowering activity and direct
Hyperlipidemia and related cardiovascular diseases, such as
atherosclerosis, are risk factors for stroke and coronary heart dis-
eases, which are among the leading causes of death in many indus-
trialized countries. Acyl-coenzyme A: cholesterol acyltransferase
(ACAT), which catalyzes intracellular cholesterol esterification,1,2
plays important roles in several physiological processes, such as
absorption of dietary and biliary cholesterol in the small
intestine,3,4 secretion of very low-density lipoprotein (VLDL) in
the liver,5–7 and accumulation of cholesteryl esters in macrophages
in the arterial wall.8–10 It is therefore believed that inhibition of
ACAT may lower plasma cholesterol level and help prevent
atherosclerosis.
It is known that expression of hepatic low-density lipoprotein
receptor (LDL-R) is extremely important for lipid homeostasis.
Statins, which are HMG-CoA reductase inhibitors that increase he-
patic LDL-R expression, are known to be effective in lowering total
cholesterol and LDL cholesterol levels in hyperlipidemic patients.11
Accordingly, it is believed that dual effectors of ACAT and LDL-R
expression may be promising agents in the treatment of hyperlip-
idemia and related cardiovascular diseases.
regressive effect on atherosclerotic lesions.12 We have also shown
that SMP-797, unlike other ACAT inhibitors, such as Avasimibe (CI-
1011) and F12511,12,13 up-regulates hepatic LDL-R expression. Fur-
thermore, SMP-797 at a concentration much higher than that
needed for LDL-R up-regulation had no effect on cholesterol syn-
thesis in HepG2 cells. These findings strongly suggest that SMP-
797 up-regulation of LDL-R is independent from its ACAT inhibi-
tory activity. Therefore, we expect SMP-797 to be a next generation
anti-hyperlipidemic agent.
In a previous paper, we have identified a series of 1,4-diarylpi-
peridine-4-methylurea compounds as novel ACAT inhibitors.14 In
particular, we have shown that a methoxy group as R1 in part-A
and as R2 at the o-position in part-B, and an amino group as R3
in part-C are essential for both ACAT inhibition and LDL-R up-reg-
ulation, (Table 1).This is quite interesting because the piperidine-
based structure of these urea compounds is completely different
from the 1,8-naphthyridine moiety in SMP-797. Here we report
in details the structure activity relationship (SAR) of this series of
compounds, particularly their effects on ACAT inhibition and
LDL-R up-regulation.
2. Chemistry
* Corresponding authors. Tel.: +81 6 6466 5185; fax: +81 6 6466 5287 (S.A.), tel.:
+81 6 6337 5815; fax: +81 6 6337 6010 (H.B.)
We initially synthesized the precursor nitriles 3–4, 6–12, and
15–19 to afford the ureas 1, 21–31, and 37–46. These nitriles were
E-mail addresses: shigehiro-asano@ds-pharma.co.jp (S. Asano), hitoshi-ban@ds-
pharma.co.jp (H. Ban).
0968-0896/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2009.04.059

S. Asano et al. / Bioorg. Med. Chem. 17 (2009) 4636–4646
4637
OH
O
MeO
N
A
H
N
H
H
N
H
N
NH2
MeO
N
NH2
O
O
N
N
O
HCl, H2O
C
B
1
SMP-797
Figure 1. Structures of SMP-797 and compound 1.
Table 1
prepared by three synthetic methods using different functional
groups (Scheme 1). The first synthetic method was conversion of
the substituent on the phenyl ring in part A. The nitriles 3 and 4
were prepared by dialkylation of the commercially available phe-
nylacetonitriles 2 with N,N-bis(2-chloroethyl)anisidine15 in the
presence of a catalytic amount of phosphonium bromide.16 The
second synthetic method was conversion of the N-(substituted
phenyl)piperidines in part B. The diol 5 was prepared by common
dialkylation of the (3-methoxyphenyl)acetonitrile with the com-
mercially available 2-(2-bromoethoxyl)tetrahydro-2H-pyran using
NaH in DMF followed by methanolysis. The diol 5 thus obtained
was converted to the nitriles 6-13 by cyclization via bis-triflate
with the appropriate amines (R2C6H4NH2 or Ph2CHNH2).17 Cycliza-
tion of the corresponding dimesylate or dibromide, which were
easily prepared by common mesylation or bromination from the
diol 5, did not give the desired compounds in sufficient yields,
probably due to different reactivity of the leaving group. The third
synthetic method was conversion of the N-(substituted pyri-
dyl)piperidines in part B. The benzohydryl group on the nitrogen
of the compound 13 was removed by palladium-catalyzed hydro-
genation to give the unsubstituted piperidine 14. The piperidine
14 thus obtained was converted to the N-pyridylpiperidines 15–
Effects of different substituents at the phenyl moiety (A, B, or C-part) on compounds
biological activity towards ACAT and LDL-R
R1
A
H
H
N
N
R3
R2
B
C
N
O
Compds
R1
R2
R3
ACATa IC50 (nM)
LDL-Rb@10ꢀ7
M
c
21
22
1
23
24
25
CI-1011
SMP-797
OMe
OMe
OMe
OMe
OMe
H
H
H
H
35
40
37
48
ꢀ
c
NH2
NH2
NH2
NH2
NH2
ꢀ
2-OMe
3-OMe
4-OMe
2-OMe
+
ꢀ
ꢀ
ꢀ
ꢀ
++
142
82
479d
31
a
Inhibitory activity for ACAT in rat macrophages.
Effect on LDL-R expression in HepG2.
10ꢀ5 M.
b
c
d
In-house data.
MeO
MeO
MeO
HN
R1
HO
HO
b
c
d
CN
CN
CN
Ph
N
CN
a
Ph
13
14
2
5
c
e
R1
MeO
MeO
R2
OMe
R2
CN
CN
CN
N
N
N
Z
X
4
2
Y
3
3
4
R1=H
R1=OBn
6
R2=H
15
R2=H
R2=H
R2=H
X=N Y=CH Z=CH
X=CH Y=N Z=CH
X=CH Y=CH Z=N
7
8
9
R2=2-OMe
R2=3-OMe
R2=4-OMe
16
17
18
19
R2=OMe X=N Y=CH Z=CH
10 R2=2-OCF3
11 R2=2-OCH2CF3
12 R2=2-OBn
R2=OBn
X=N Y=CH Z=CH
Scheme 1. Synthesis of nitriles 3, 4, 6–12, and 15–19. Reagents and conditions: (a) N,N-bis(2-chloroethyl)anisidine, CH3(CH2)15P+Bu3ꢁBrꢀ, 50% NaOHaq, 100 °C; (b) (1)
BrCH2CH2OTHP, NaH, DMF, 0 °C?rt; (2) p-TsOH monohydrate, MeOH, rt; (c) (1) triflic anhydride, N,N-diisopropylethylamine, EtOAc, ꢀ30 °C; (2) R2C6H4NH2, or Ph2CHNH2,
N,N-diisopropylethylamine, ꢀ30 °C?rt; (d) 10% Pd/C, HCO2NH4, EtOH, reflux; (e) pyridyl halide, Pd2(dba)3, (S)-(ꢀ)-BINAP, NaOtBu, toluene, 80 °C.

4638
S. Asano et al. / Bioorg. Med. Chem. 17 (2009) 4636–4646
19 by coupling reaction with appropriate pyridyl halide in the
presence of Pd2(dba)3 and (S)-(ꢀ)-BINAP.18
atmosphere to afford the intermediates 34–36 in good yield. Alkyl-
ation of the hydroxyl group of 34–36 with an appropriate alkylha-
lide using cesium carbonate as base followed by deprotection of
the benzyl and/or Boc group provided the desired compounds
37–46.
Synthesis of the desired ureas 1 and 21–31 was achieved as
illustrated in Scheme 2. Reduction of the nitriles 3, 6–11, and
15–18 using LiAlH4 followed by coupling reaction with the corre-
sponding phenylcarbamates 32 or 3314,19 afforded the desired urea
compounds. The primary amines 20 were used for the urea gener-
ation step without purification because of their high polarity. In the
case of ureas 1 and 22–31 the Boc group was removed by 10%
methanolic HCl in the final step to afford the desired compounds
as HCl salt.
3. Results and discussion
Although compound 1 had an ACAT inhibitory activity compa-
rable to that of SMP-797, its up-regulatory activity for LDL-R was
weaker than that of SMP-797 (Table 1). Therefore, to improve both
biological activities of compound 1, we designed further structural
modifications. The common structural moiety in compound 1 and
SMP-797 is the 4-amino-2,6-diisopropylphenylurea (Fig. 1). In the
course of our SAR study of SMP-797 derivatives, we found that
introduction of a long alkyl chain to N(1)-position of 1,8-naph-
The various alkoxy-substituted compounds 37–46 on the aryl
moiety in A or B-part (Fig. 1) were prepared as illustrated in
Scheme 3. Reduction of the nitrile 4, 12, or 19 followed by coupling
reaction with 33 produced urea derivatives, which underwent
deprotection of the benzyl group over Pd(OH)2/C under hydrogen
R1
N
R1
N
R1
2HCl
H
H
a
b or c
NH2
N
N
R3
R2
Z
R2
Z
R2
4
CN
N
O
X
X
2
c
Y
Y
3
R1=OMe R2=H
R3=H
21
3, 6-11, 15-18
20
22 R1=OMe R2=H
R3=NH2
R3=NH2
R3=NH2
R3=NH2
R3=NH2
R3=NH2
MeO
1
R1=OMe R2=2-OMe
R2=3-OMe
23 R1=OMe
2HCl
NH2
24 R1=OMe R2=4-OMe
H
H
R2
N
N
R1=H
R2=2-OMe
25
H
O
N
R3
26 R1=OMe R2=2-OCF3
N
O
R1=OMe R2=2-OCH2CF3 R3=NH2
27
O
Z
X
O2N
Y
32 R3=H
33 R3=NHBoc
R2=H
X=N Y=CH Z=CH
X=CH Y=N Z=CH
X=CH Y=CH Z=N
X=N Y=CH Z=CH
28
29 R2=H
30 R2=H
31 R2=OMe
Scheme 2. Synthesis of ureas 1 and 21–31. Reagents and conditions: (a) LiAlH4, THF, reflux; (b) 32, THF, rt; (c) (1) 33, THF, rt; (2) 10% HCl/MeOH, rt.
R1
N
R1
N
a, b, c
d or e or f
H
H
R2
N
N
NHBoc
R2
CN
O
X
X
34 R1=OMe R2=OH
4, 12, 19
X=CH
35 R1=OH R2=OMe X=CH
R1=OMe R2=OH X=N
36
R1
N
37 R1=OMe
R2=OH
X=CH n=2
X=CH n=2
X=CH n=2
H
H
R1=OMe
R2=OiPr
R2=OnBu
38
R2
N
N
NH2
nHCl
39 R1=OMe
40 R1=OMe
R2=O(CH2)3NH2 X=CH n=3
O
R1=OMe
R2=O(CH2)3NMe2
R2=O(CH2)2OH
R2=O(CH2)3OH
R2=OMe
X=CH n=3
X=CH n=2
X=CH n=2
X=CH n=2
X=CH n=2
41
X
42 R1=OMe
R1=OMe
44 R1=OH
43
45 R1=O(CH2)3OH R2=OMe
R1=OMe
R2=O(CH2)3OH
X=N
n=2
46
Scheme 3. Synthesis of ureas 37–46. Reagents and conditions: (a) LiAlH4, THF, reflux; (b) 33, THF, rt; (c) 20% Pd(OH)2/C, H2 (0.3 MPa), MeOH, rt; (d) 10% HCl/MeOH, rt; (e) (1)
alkyl halide, Cs2CO3, DMF, 60 °C; (2) 10% HCl/MeOH, rt; (f) (1) alkyl halide, Cs2CO3, DMF, 60 °C; (2) 20% Pd(OH)2/C, 5 N HClaq, H2 (0.45 MPa), MeOH, rt; (3) 10% HCl/MeOH, rt.

S. Asano et al. / Bioorg. Med. Chem. 17 (2009) 4636–4646
4639
thyridine enhanced ACAT inhibitory activity.20 Thus, we hypothe-
sized that the 1-arylpiperidine part of compound 1 and the 1,8-
naphthyridine part of SMP-797 play a similar role in ACAT inhibi-
tory activity. Accordingly, we assumed that modification of the
methoxy group (R2) may translate to improvement of this biologi-
cal activity.
Table 3
Effects of substitution of the alkoxy group at the phenyl moiety (A or B-part) with a
hydrophilic group on compounds biological activity towards ACAT and LDL-R and
solubility
A
R1
Replacement of the methoxy group at R2 with other alkoxy
groups gave compounds with ACAT inhibitory activity comparable
to that of SMP-797 and improved up-regulatory activity for LDL-R
expression (Table 2). Except for compound 26, compounds 1, 27,
and 38–39 inhibited ACAT with IC50 values similar to that of SMP-
797, suggesting that elongation of the alkyl chain has no beneficial
effect on ACAT inhibitory activity. Surprisingly, the up-regulatory
activity for LDL-R expression tended to increase by alkyl chain elon-
gation. In particular, compound 39showed biological activities com-
parable to those of SMP-797 but better than those of compound 1.
From these findings we concluded that lipophilicity and/or substitu-
ent size are important for good LDL-R up-regulatory activity.
Although compound 39 looked promising, its solubility was low
(0.0003 mg/mL, at pH 7.4), which is a drawback for oral bioavailabil-
ity. We therefore focused on the substituent size and designed com-
pounds with a hydrophilic group in the alkyl chain.
H
H
R2
N
N
NH2
2HCl
B
N
O
Compds R1
R2
ACATa
IC50
(nM))
LDL-
Solubility (mg/
ml)@ pH 7.4
Rb@10ꢀ7
M
39
OMe
OnBu
OH
32
246
195
++
ꢀ
0.0003
Ntd
0.032
>0.25
Ntd
37
OMe
OMe
OMe
OMe
OMe
OH
40c
41c
42
O(CH2)3NH2
O(CH2)3NMe2 239
O(CH2)2OH
O(CH2)3OH
OMe
++
Ntd
++
++
ꢀ
96
18
797
62
31
43
44
45
SMP-
0.022
Ntd
O(CH2)3OH OMe
+
++
Ntd
0.010
797
To improve the solubility we introduced an amino, dimethyl-
amino, or a hydroxyl group as hydrophilic functional group to
the alkoxy moiety at the phenyl moiety (A or B-part). In addition
prepared the phenol compounds 37 and 44 and used them as ref-
erence. ACAT inhibitory activity, LDL-R up-regulatory activity, and
solubility of the synthesized compounds (37 and 39–45) are sum-
marized in Table 3. Compounds 37 and 44 with a phenolic hydro-
xyl group had decreased ACAT inhibitory activity. Similarly, the
aminopropoxyl compounds 40 and 41 showed decreased inhibi-
tory activity against ACAT. These findings indicate that a basic sub-
stituent at the R2 position is not favorable for ACAT inhibition. The
hydroxyalkoxy compounds 42 and 43 showed an LDL-R up-regula-
tory activity equivalent to that of the lipophilic compound 39, and
their ACAT inhibitory activity increased in accordance with elonga-
tion of the alkyl-chain. With these findings we speculated that size
of the substituent is important for LDL-R up-regulatory activity.
Particularly, compound 43 showed a more potent ACAT inhibitory
activity than that of 39 or SMP-797. Furthermore and as expected,
the solubility of 43 was improved by 70-fold compared to that of
39 (0.022 mg/mL versus 0.0003 mg/mL, at pH 7.4). Actually, the
calculated clogP value supported this finding (43; clog P = 5.91 vs
39; clog P = 7.70).21 Based on SAR information of SMP-797, intro-
duction of a 3-hydroxypropoxyl group onto the A-part (compound
45) gave a biological activity inferior to that of 1 or 43.
a
b
c
Inhibitory activity for ACAT in rat macrophages.
Effect on LDL-R expression in HepG2.
3HCl salts.
d
Nt: not tested.
Finally, to obtain further improvement in the solubility, we re-
placed the phenyl moiety of the B-part by a pyridyl one. The inhib-
itory activity for ACAT of the prepared compounds 1, 28–31, 43,
and 46 and their up-regulation of LDL-R are summarized in Table
4. ACAT inhibitory activity of the 2-pyridyl compound 28 was
much higher than that of the 3-pyridyl 29 or the 4-pyridyl 30.
Based on SAR information obtained so far, introduction of an alk-
oxy group to position 3 of the pyridyl moiety in 28 was viewed
as a good way to improve both biological activities. As expected,
compounds 31 and 46 showed more potent inhibitory activity
against ACAT than to the corresponding compound 1 and 43,
respectively. Unfortunately, these compounds had no up-regula-
tory activity for LDL-R expression. These findings indicate that
the pyridine ring is not suitable as B-part for LDL-R up-regulation
Table 4
Effects of substitution at the phenyl or the pyridyl moiety (B-part) on compounds
biological activity towards ACAT and LDL-R
MeO
Table 2
Effects of the alkoxy substituent at the phenyl moiety (B-part) on compounds
biological activity towards ACAT and LDL-R
H
H
R2
N
N
NH2
2HCl
MeO
N
O
Z
X
B
Y
H
H
R2
N
N
NH2
2HCl
B
N
LDL-Rb@10ꢀ7
M
O
Compds
X
Y
Z
R2
OMe
ACATa IC50 (nM)
1
43
28
29
30
31
46
SMP-797
CH
CH
N
CH
CH
N
CH
CH
CH
N
CH
CH
CH
CH
CH
CH
CH
N
37
18
32
466
>1000
6
4
31
+
O(CH2)3OH
++
ꢀ
H
H
H
OMe
Compds
R2
ACATa IC50 (nM)
LDL-Rb@10ꢀ7
M
Ntd
Ntd
1
26
27
38
39
SMP-797
OMe
OCF3
37
68
48
37
32
31
+
c
++
++
+
++
++
CH
CH
+
OCH2CF3
N
O(CH2)3OH
ꢀ
OiPr
++
OnBu
a
Inhibitory activity for ACAT in rat macrophages.
Effect on LDL-R expression in HepG2.
10ꢀ5 M.
b
c
a
Inhibitory activity for ACAT in rat macrophages.
Effect on LDL-R expression in HepG2.
b
d
Nt: not tested.

4640
S. Asano et al. / Bioorg. Med. Chem. 17 (2009) 4636–4646
probably due to its basicity and/or hydrophilicity. It is therefore
suggested that the mechanisms of ACAT inhibition and LDL-R up-
regulation are completely different.
5.1.2. 1-(2-Methoxyphenyl)-4-(3-benzyloxyphenyl)piperidine-
4-carbonitrile (4)
Compound 4 was prepared from (3-benzyloxyphenyl)acetoni-
trile in a manner similar to that described for compound 3 with
a yield of 77% as white needle-like crystals (MeOH). Mp 102–
103 °C; 1H NMR (CDCl3, 300 MHz) d 2.21 (2H, m), 2.36 (2H, m),
3.11 (2H, m), 3.57 (2H, m), 3.88 (3H, s), 5.08 (2H, s), 6.87–6.98
(3H, m), 7.05 (2H, m), 7.18 (1H, m), 7.20 (1H, m), 7.24–7.46 (6H,
m); 13C NMR (CDCl3, 75 MHz) d 36.8, 42.8, 48.5, 55.4, 70.1, 111.1,
112.8, 114.1, 118.2, 118.8, 121.0, 121.9, 123.4, 127.5, 128.0,
128.6, 130.0, 136.6, 140.9, 141.8, 152.1, 159.2; IR (ATR) 2239,
4. Conclusion
Based on the 1,4-diarylpiperidine-4-methylurea 1,
a new
ACAT inhibitor, we examined in this study the SAR of a series
of compounds prepared by replacing the substituent at A or B-
part of 1. Introduction of long alkoxy group was effective in
improving both ACAT inhibitory activity and LDL-R up-regulatory
activity. Particularly, 3-hydroxypropoxy group on the phenyl
moiety of B-part led to improved solubility, while keeping both
biological activities. Compound 43 inhibited ACAT with an IC50
value of 18 nM, which is superior to that of a known ACAT
inhibitor, CI-1011 (IC50 = 479 nM, Table 1). In addition, 43 re-
vealed an LDL-R up-regulatory activity comparable to that of
SMP-797. We therefore expect 43 to be a novel ACAT inhibitor.
Although in this study we were able to synthesize compounds
that have improved LDL-R up-regulatory activity, the mechanism
of this up-regulation is still unclear. Studies to unveil this mech-
anism are now underway.
1579, 1504 cmꢀ1
; MS (ESI) m/z 399 (M+1). Anal. Calcd for
C26H26N2O2: C, 78.36; H, 6.58; N, 7.03. Found: C, 78.32; H, 6.40;
N, 7.15.
5.1.3. 4-Hydroxy-2-(2-hydroxyethyl)-2-(3-
methoxyphenyl)butanenitrile (5)
To a suspension of 55% NaH disparaged in mineral oil (3.26 g,
0.075 mol) in dry DMF (50 mL) was added dropwise a solution of
(3-methoxyphenyl)acetonitrile (5.0 g, 0.034 mol) and (2-bromo-
ethyl)tetrahydropyranyl ether (14.9 g, 0.0713 mol) in dry Et2O at
0 °C, and the mixture was stirred at room temperature for 1 h.
The reaction mixture was then poured into saturated NH4Cl solu-
tion, and the resulting mixture was extracted with Et2O. The organ-
ic layer was washed with brine and dried over anhydrous
magnesium sulfate. After filtration, the solvent was removed in va-
cuo. The residue was dissolved in MeOH (50 mL), and p-TsOH
monohydrate (646 mg, 3.4 mmol) was added and stirred at room
temperature for 1 h. The solvent was removed in vacuo, and the
residue was diluted with EtOAc and saturated NH4Cl solution.
The organic layer was separated, washed with saturated NaHCO3
solution, brine, and dried over anhydrous magnesium sulfate. After
filtration, the solvent was removed in vacuo, and the resulting solid
was triturated with Et2O to give 5 (5.94 g, 74%) as a pale yellow so-
lid. Mp 89–90 °C; 1H NMR (CDCl3, 300 MHz) d 2.17 (4H, m), 3.18
(2H, m), 3.37 (2H, m), 3.76 (3H, s), 4.59 (2H, t, J = 5.1 Hz), 6.92
(1H, d, J = 8.0 Hz), 6.96 (1H, s), 7.00 (1H, d, J = 8.0 Hz), 7.33 (1H,
dd, J = 8.0, 8.0 Hz); 13C NMR (CDCl3, 75 MHz) d 42.3, 42.9, 55.2,
57.3, 111.7, 112.6, 117.8, 122.1, 130.0, 139.8, 159.5; IR (ATR)
3243, 2237, 1610, 1585 cmꢀ1; MS (APCI) m/z 236 (M+1). Anal.
Calcd for C13H17NO3: C, 66.36; H, 7.28; N, 5.95. Found: C, 66.46;
H, 7.34; N, 5.91.
5. Experimental
5.1. Chemistry
Melting points (MP) were determined on an electrothermal
apparatus without correction. IR spectra were recorded on a JEOL
JIR-SPX60 spectrometer as ATR. NMR spectra were recorded on a
JEOL JNM-LA300 spectrometer. Chemical shifts (r) are given in
parts per million, and TMS was used as the internal standard for
spectra obtained in DMSO-d6 and CDCl3. All J values are given in
Hz. Mass spectra were recorded on a Bruker Daltonics esquire
3000plus and a Thermo Fisher Scientific LTQ orbitrap Discovery
MS equipment. Elemental analysis was performed on a CE Instru-
ment EA1110 and a Yokokawa analytical system IC7000. Reagents
and solvents were used as obtained from commercial suppliers
without further purification. Column chromatography was carried
out using a Yamazen W-prep system, and performed using pre-
packed silica gel or amino silica gel. Reaction progress was deter-
mined by TLC analysis on silica gel or amino silica gel coated glass
plate. Visualization was done with UV light (254 nm) or iodine. All
reactions were carried out under a nitrogen atmosphere unless
otherwise mentioned.
5.1.4. 4-(3-Methoxyphenyl)-1-phenylpiperidine-4-carbonitrile
(6)
5.1.1. 1-(2-Methoxyphenyl)-4-phenylpiperidine-4-carbonitrile
(3)
To a solution of 5 (470 mg, 2.0 mmol) in dry EtOAc (10 mL) at
ꢀ30 °C was slowly added trifluoromethanesulfonic anhydride
To a solution of phenylacetonitrile (117 mg, 1.0 mmol) and N,N-
bis(2-chloroethyl)anisidine (248 mg, 1.0 mmol) in 50% NaOH solu-
tion (1.2 mL) was added hexadecyltributylphosphonium bromide
(25.4 mg, 0.050 mmol), and the mixture was stirred at 100 °C for
2 h. The reaction was quenched by adding H2O, and the mixture
was extracted with Et2O. The organic layer was washed with brine,
and dried over anhydrous magnesium sulfate. After filtration, the
solvent was removed in vacuo, and the residue was purified by sil-
ica gel column chromatography. The solvent was removed in va-
cuo, and the resulting solid was triturated with MeOH to give 3
(164 mg, 56%) as white needle-like crystal. Mp 97–98 °C; 1H
NMR (CDCl3, 300 MHz) d 2.22 (2H, m), 2.36 (2H, m), 3.12 (2H,
m), 3.59 (2H, m), 3.89 (3H, s), 6.91 (1H, m), 6.98 (1H, m), 7.03
(2H, m), 7.32 (1H, m), 7.43 (2H, m), 7.56 (2H, m); 13C NMR (CDCl3,
75 MHz) d 36.9, 42.9, 48.5, 55.4, 111.1, 118.8, 121.1, 122.0, 123.5,
125.7, 128.1, 129.0, 140.2, 141.0, 152.2; IR (ATR) 2238, 1597,
1585 cmꢀ1; MS (ESI) m/z 293 (M+1). Anal. Calcd for C19H20N2O:
C, 78.05; H, 6.89; N, 9.58. Found: C, 77.91; H, 6.90; N, 9.58.
(704
amine (730
was added, followed by addition of N,N-diisopropylethylamine
(730
L, 4.2 mmol). The reaction mixture was kept at ꢀ30 °C for
lL, 4.2 mmol) followed by addition of N,N-diisopropylethyl-
lL, 4.2 mmol). After 15 min, aniline (218 lL, 2.4 mmol)
l
1 h and at room temperature for 2 h. The reaction was then
quenched by adding water and the mixture was extracted with
EtOAc. The organic layer was washed with brine and dried over
anhydrous magnesium sulfate. After filtration, the solvent was re-
moved in vacuo, and the residue was purified by silica gel column
chromatography and triturated with MeOH to give 6 (488 mg, 84%)
as white needle-like crystal. Mp 86–87 °C; 1H NMR (CDCl3,
300 MHz) d 2.22 (4H, m), 3.24 (2H, m), 3.76 (2H, m), 3.84 (3H, s),
6.90 (2H, m), 7.02 (2H, m), 7.07 (1H, m), 7.12 (1H, m), 7.30 (2H,
m), 7.34 (1H, dd, J = 7.9, 7.9 Hz); 13C NMR (CDCl3, 75 MHz) d 36.3,
42.7, 47.5, 55.4, 112.0, 113.2, 117.0, 117.8, 120.4, 121.6, 129.2,
130.1, 141.5, 151.0, 160.1; IR (ATR) 2227, 1601, 1581 cmꢀ1; MS
(ESI) m/z 293 (M+1). Anal. Calcd for C19H20N2O: C, 78.05; H, 6.89;
N, 9.58. Found: C, 78.14; H, 6.83; N, 9.67.

S. Asano et al. / Bioorg. Med. Chem. 17 (2009) 4636–4646
4641
5.1.5. 1-(2-Methoxyphenyl)-4-(3-methoxyphenyl)piperidine-4-
carbonitrile (7)
123.2, 123.7, 130.0, 141.6, 142.1, 150.0, 160.0; IR (ATR) 2241,
1608, 1601, 1583 cmꢀ1; MS (ESI) m/z 391 (M+1). Anal. Calcd for
C21H21F3N2O2: C, 64.61; H, 5.42; F, 14.60; N, 7.18. Found: C,
64.32; H, 5.41; F, 14.63; N, 7.31.
Compound 7 was prepared from 5 and 2-methoxyaniline in a
manner similar to that described for compound 6 with a yield of
77% as white needle-like crystal (MeOH). Mp 110–111 °C; 1H
NMR (CDCl3, 300 MHz) d 2.22 (2H, m), 2.37 (2H, m), 3.12 (2H,
m), 3.58 (2H, m), 3.84 (3H, s), 3.89 (3H, s), 6.91 (2H, m), 6.93
(1H, m), 7.04 (2H, m), 7.10 (1H, m), 7.18 (1H, m), 7.34 (1H, dd,
J = 8.0, 8.0 Hz); 13C NMR (CDCl3, 75 MHz) d 36.3, 42.9, 48.5, 55.3,
55.4, 111.1, 111.7, 113.4, 117.9, 118.8, 121.1, 122.0, 123.5, 130.0,
140.9, 141.8, 152.2, 160.0; IR (ATR) 2233, 1608, 1583 cmꢀ1; MS
(ESI) m/z 323 (M+1). Anal. Calcd for C20H22N2O2: C, 74.51; H,
6.88; N, 8.69. Found: C, 74.28; H, 6.87; N, 8.70.
5.1.10. 4-(3-Methoxyphenyl)-1-(2-benzyloxyphenyl)piperidine-
4-carbonitrile (12)
Compound 12 was prepared from 5 and 2-benzyloxyaniline in a
manner similar to that described for compound 6 with a yield of
82% as white needle-like crystal (MeOH). Mp 103–104 °C; 1H
NMR (CDCl3, 300 MHz) d 2.19 (2H, m), 2.27 (2H, m), 3.14 (2H,
m), 3.64 (2H, m), 3.82 (3H, s), 5.13 (2H, s), 6.89 (1H, m), 6.94–
7.06 (5H, m), 7.12 (1H, m), 7.28–7.40 (4H, m), 7.43 (2H, m); 13C
NMR (CDCl3, 75 MHz) d 36.6, 42.7, 48.3, 55.2, 70.3, 111.7, 113.1,
113.3, 117.7, 118.9, 121.5, 121.8, 123.1, 127.1, 127.7, 128.4,
129.9, 137.1, 141.4, 141.7, 151.4, 159.9; IR (ATR) 2235, 1601,
1583 cmꢀ1; MS (ESI) m/z 399 (M+1). Anal. Calcd for C26H26N2O2:
C, 78.36; H, 6.58; N, 7.03. Found: C, 78.53; H, 6.59; N, 7.23.
5.1.6. 1,4-Bis(3-methoxyphenyl)piperidine-4-carbonitrile (8)
Compound 8 was prepared from 5 and 3-methoxyaniline in a
manner similar to that described for compound 6 with a yield of
89% as a colorless oil. 1H NMR (CDCl3, 300 MHz) d 2.23 (4H, m),
3.26 (2H, m), 3.76 (2H, m), 3.81 (3H, s), 3.84 (3H, s), 6.51 (1H, d,
J = 8.1 Hz), 6.58 (1H, s), 6.63 (1H, d, J = 8.1 Hz), 6.90 (1H, m), 7.06
(1H, m), 7.12 (1H, m), 7.21 (1H, dd, J = 8.0, 8.0 Hz), 7.34 (1H, dd,
J = 8.0, 8.0 Hz); 13C NMR (CDCl3, 75 MHz) d 36.0, 42.7, 47.6, 55.2,
55.3, 103.5, 107.1, 109.7, 111.9, 113.3, 117.8, 121.2, 123.9, 130.0,
130.1, 141.3, 160.1, 160.6; IR (ATR) 2235, 1601, 1583 cmꢀ1; MS
(ESI) m/z 323 (M+1). Anal. Calcd for C20H22N2O2ꢁ1/5H2O: C,
73.68; H, 6.93; N, 8.59. Found: C, 74.07; H, 6.86; N, 8.64.
5.1.11. 4-(3-Methoxyphenyl)-1-diphenylmethylpiperidine-4-
carbonitrile (13)
Compound 13 was prepared from 5 and benzohydrylamine in a
manner similar to that described for compound 6 with a yield of
82% as white needle-like crystal (MeOH). Mp 127–128 °C; 1H
NMR (CDCl3, 300 MHz) d 2.06 (2H, m), 2.13 (2H, m), 2.34 (2H,
m), 2.94 (2H, m), 3.78 (3H, s), 4.32 (1H, s), 6.83 (1H, dd, J = 7.9,
2.0 Hz), 7.01 (1H, d, J = 2.0 Hz), 7.06 (1H, d, J = 7.9 Hz), 7.15 (2H,
m), 7.24 (5H, m), 7.38 (4H, m); 13C NMR (CDCl3, 75 MHz) d 36.8,
42.9, 49.5, 55.3, 76.1, 112.0, 113.1, 117.9, 122.2, 127.1, 127.8,
128.6, 130.0, 141.9, 142.6, 160.0; IR (ATR) 2229, 1599 cmꢀ1; MS
(ESI) m/z 383 (M+1). Anal. Calcd for C26H26N2O: C, 81.64; H, 6.85;
N, 7.32. Found: C, 81.30; H, 6.78; N, 7.40.
5.1.7. 4-(3-Methoxyphenyl)-1-(4-methoxyphenyl)piperidine-4-
carbonitrile (9)
Compound 9 was prepared from 5 and 4-methoxyaniline in a
manner similar to that described for compound 6 with a yield of
87% as white needle-like crystals (MeOH). Mp 101–102 °C; 1H
NMR (CDCl3, 300 MHz) d 2.23 (2H, m), 2.27 (2H, m), 3.17 (2H,
m), 3.49 (2H, m), 3.78 (3H, s), 3.84 (3H, s), 6.86 (1H, m), 6.88
(2H, d, J = 9.2 Hz), 6.89 (1H, m), 6.96 (2H, d, J = 9.2 Hz), 7.09 (1H,
m), 7.14 (1H, m), 7.34 (1H, dd, J = 8.0, 8.0 Hz); 13C NMR (CDCl3,
75 MHz) d 36.6, 42.6, 49.0, 55.3, 55.5, 111.9, 113.2, 114.4, 117.8,
119.3, 121.7, 130.0, 141.6, 145.4, 154.3, 160.0; IR (ATR) 2239,
5.1.12. 4-(3-Methoxyphenyl)piperidine-4-carbonitrile (14)
To a solution of 13 (5.0 g, 0.0131 mol) in MeOH (50 mL) and THF
(50 mL) were added ammonium formate (10 g) and 10% Pd/C (50%
wet, 1.0 g), and the mixture was stirred at reflux for 1 h and then
filtered through Celite. The filtrate was concentrated, and the res-
idue was purified by amino silica gel column chromatography to
give 14 (1.76 g, 62%) as colorless oil. 1H NMR (CDCl3, 300 MHz) d
7.32 (1H, dd, J = 8.1, 8.1 Hz), 7.10 (1H, m), 7.04 (1H, m), 6.86 (1H,
m), 3.83 (3H, s), 3.17 (4H, m), 2.07 (2H, m), 1.98 (2H, m); 13C
NMR (DMSO-d6, 75 MHz) d 37.2, 43.2, 43.9, 55.3, 111.8, 113.1,
117.8, 122.1, 130.0, 142.1, 160.0; IR (ATR) 3342, 2233, 1601,
1583 cmꢀ1; MS (ESI) m/z 217 (M+1). Anal. Calcd for C13H16N2Oꢁ1/
2H2O: C, 69.31; H, 7.61; N, 12.43. Found: C, 69.44; H, 7.42; N,
12.55.
1608, 1583 cmꢀ1
; MS (ESI) m/z 323 (M+1). Anal. Calcd for
C20H22N2O2: C, 74.51; H, 6.88; N, 8.69. Found: C, 74.46; H, 6.85;
N, 8.77.
5.1.8. 4-(3-Methoxyphenyl)-1-[2-
(trifluoromethoxy)phenyl]piperidine-4-carbonitrile (10)
Compound 10 was prepared from 5 and 2-trifluoromethoxyan-
iline in a manner similar to that described for compound 6 with a
yield of 26% as white needle-like crystal (Et2O). Mp 101–102 °C; 1H
NMR (CDCl3, 300 MHz) d 2.16 (2H, m), 2.22 (2H, m), 3.17 (2H, m),
3.41 (2H, m), 3.78 (3H, s), 6.84 (1H, dd, J = 8.0, 2.3 Hz), 6.95–7.22
(6H, m), 7.28 (1H, dd, J = 8.0, 8.0 Hz); 13C NMR (CDCl3, 75 MHz) d
36.6, 42.5, 48.8, 55.4, 112.1, 113.2, 117.9, 120.6, 121.8, 122.0,
123.4, 127.7, 130.1, 141.5, 142.5, 160.0; IR (ATR) 2233, 1605,
1585 cmꢀ1; MS (ESI) m/z 377 (M+1). Anal. Calcd for C20H19F3N2O2:
C, 63.82; H, 5.09; F, 15.14; N, 7.44. Found: C, 63.48; H, 5.05; F,
15.16; N, 7.51.
5.1.13. 4-(3-Methoxyphenyl)-1-pyridin-2-ylpiperidine-4-
carbonitrile (15)
To a solution of 14 (200 mg, 0.925 mmol) in toluene (4.0 mL)
were added 2-bromopyridine (98.0
lL, 1.02 mmol), Pd2(dba)3
(84.7 mg, 0.0925 mmol), (S)-(ꢀ)-BINAP (115 mg, 0.185 mmol),
and sodium tert-butoxide (178 mg, 1.85 mmol), and the mixture
was stirred at 90 °C for 2 h and filtered through Celite. The filtrate
was diluted with EtOAc and water. The organic layer was sepa-
rated, washed with brine, and dried over anhydrous magnesium
sulfate. After filtration, the solvent was removed in vacuo, and
the residue was purified by silica gel column chromatography to
give 15 (224 mg, 82%) as a yellow oil. 1H NMR (CDCl3, 300 MHz)
d 8.22 (1H, m), 7.52 (1H, m), 7.33 (1H, dd, J = 8.0, 8.0 Hz), 7.09
(1H, m), 7.03 (1H, m), 6.88 (1H, m), 6.72 (1H, d, J = 8.6 Hz), 6.67
(1H, m), 4.49 (2H, m), 3.83 (3H, s), 3.32 (2H, m), 2.19 (2H, m),
2.09 (2H, m); 13C NMR (CDCl3, 75 MHz) d 35.9, 43.1, 43.2, 55.3,
107.2, 112.0, 113.2, 113.7, 117.8, 121.7, 130.1, 137.7, 141.5,
148.1, 158.9, 160.0; IR (ATR) 2233, 1591, 1562 cmꢀ1; MS (ESI) m/
5.1.9. 4-(3-Methoxyphenyl)-1-[2-(2,2,2-
trifluoroethoxy)phenyl]piperidine-4-carbonitrile (11)
Compound 11 was prepared from 5 and 2-(20,20,20-trifluoroeth-
oxy)aniline22,23 in a manner similar to that described for com-
pound 6 with a yield of 50% as white needle-like crystal (MeOH).
Mp 84–85 °C; 1H NMR (CDCl3, 300 MHz) d 2.22 (2H, m), 2.27
(2H, m), 3.14 (2H, m), 3.55 (2H, m), 3.83 (3H, s), 4.37 (2H, q,
J = 8.2 Hz), 6.89 (2H, m), 6.98–7.10 (3H, m), 7.14 (1H, m), 7.34
(1H, dd, J = 8.0, 8.0 Hz); 13C NMR (CDCl3, 75 MHz) d 36.6, 42.6,
48.4, 55.2, 66.7 (q), 111.9, 113.1, 115.0, 117.8, 119.4, 121.8,

4642
S. Asano et al. / Bioorg. Med. Chem. 17 (2009) 4636–4646
z 294 (M+1). Anal. Calcd for C18H19N3O: C, 73.69; H, 6.53; N, 14.32.
Found: C, 73.47; H, 6.47; N, 14.20.
solution. The resulting mixture was stirred at room temperature
for 1 h, dried over anhydrous magnesium sulfate, and filtered
through Celite. The filtrate was concentrated to give an amine.
The amine was dissolved in dry THF (3.0 mL), then 4-nitro-
phenyl(2,6-diisopropylphenyl)carbamate 32 (205 mg, 0.60 mmol)
was added to the solution, and the mixture was stirred at room
temperature for 1 h. The reaction was then quenched by adding
saturated NaHCO3 solution and extracted with EtOAc. The organic
layer was washed with saturated NaHCO3 solution, brine, and
dried over anhydrous magnesium sulfate. After filtration, the sol-
vent was removed in vacuo, and the residue was purified by amino
silica gel column chromatography to give 21 (229 mg, 92%) as a
white amorphous. 1H NMR (DMSO-d6, 60 °C, 300 MHz) d 1.10
(12H, d, J = 6.8 Hz), 1.98 (2H, m), 2.08 (2H, m), 3.02 (2H, m), 3.07
(2H, m), 3.36 (2H, m), 3.38 (2H, d, J = 6.1 Hz), 3.77 (3H, s), 6.79
(1H, dd, J = 7.2, 7.2 Hz), 6.82 (1H, m), 6.90 (2H, m), 6.92 (1H, m),
6.98 (1H, m), 7.07 (2H, d, J = 7.2 Hz), 7.16 (3H, m), 7.28 (1H, dd,
J = 8.0, 8.0 Hz), 7.31 (1H, s); 13C NMR (DMSO-d6, 75 MHz) d 23.2,
27.5, 31.9, 40.6, 44.7, 48.2, 54.7, 110.9, 112.8, 115.1, 118.0, 118.7,
122.4, 126.5, 128.6, 129.1, 132.8, 146.0, 146.5, 150.8, 156.6,
159.2; IR (ATR) 3315, 1668, 1637, 1598 cmꢀ1; MS (ESI) m/z 500
(M+1). Anal. Calcd for C32H41N3O2: C, 76.92; H, 8.27; N, 8.41.
Found: C, 76.64; H, 8.23; N, 8.56.
5.1.14. 4-(3-Methoxyphenyl)-1-pyridin-3-ylpiperidine-4-
carbonitrile (16)
Compound 16 was prepared from 14 and 3-bromopyridine in a
manner similar to that described for compound 15 with a yield of
67% as a pale yellow crystal (Et2O). Mp 105–106 °C; 1H NMR
(CDCl3, 300 MHz) d 8.38 (1H, d, J = 2.8 Hz), 8.14 (1H, dd, J = 4.4,
1.5 Hz), 7.34 (1H, dd, J = 8.0, 8.0 Hz), 7.24 (1H, m), 7.18 (1H, dd,
J = 8.3, 4.4 Hz), 7.10 (1H, m), 7.06 (1H, m), 6.88 (1H, dd, J = 8.0,
2.1 Hz), 3.82 (3H, s), 3.75 (2H, m), 3.25 (2H, m), 2.23 (4H, m); 13C
NMR (CDCl3, 75 MHz) d 36.0, 42.5, 46.8, 55.4, 112.0, 113.3, 117.7,
121.4, 123.3, 123.7, 130.2, 139.2, 141.0, 141.1, 146.7, 160.1; IR
(ATR) 2227, 1608, 1579, 1566 cmꢀ1; MS (ESI) m/z 294 (M+1). Anal.
Calcd for C18H19N3Oꢁ1/4H2O: C, 72.58; H, 6.60; N, 14.11. Found: C,
72.73; H, 6.40; N, 14.05.
5.1.15. 4-(3-Methoxyphenyl)-1-pyridin-4-ylpiperidine-4-
carbonitrile (17)
Compound 17 was prepared from 14 and 4-iodopyridine in a
manner similar to that described for compound 15 with a yield
of 50% as white needle-like crystal (Et2O). Mp 112–113 °C; 1H
NMR (CDCl3, 300 MHz) d 8.32 (2H, d, J = 6.4 Hz), 7.34 (1H, dd,
J = 8.0, 8.0 Hz), 7.05 (1H, d, J = 8.0 Hz), 7.02 (1H, dd, J = 2.1,
2.1 Hz), 6.89 (1H, dd, J = 8.0, 2.1 Hz), 6.73 (2H, d, J = 6.4 Hz), 4.03
(2H, m), 3.83 (3H, s), 3.33 (2H, m), 2.20 (2H, m), 2.09 (2H, m);
13C NMR (CDCl3, 75 MHz) d 35.5, 42.8, 44.1, 55.4, 108.8, 112.0,
113.3, 117.6, 121.2, 130.3, 140.8, 150.6, 154.3, 160.1; IR (ATR)
5.1.19. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[4-(3-
methoxyphenyl)-1-phenylpiperidin-4-yl]methyl}urea
dihydrochloride (22)
To a solution of 6 (146 mg, 0.50 mmol) in dry THF (3.0 mL) was
added lithium aluminum hydride (37.9 mg, 1.0 mmol), and the mix-
ture was stirred at reflux for 1 h and quenched with NaOH solution.
The resulting mixture was stirred at room temperature for 1 h, dried
over anhydrous magnesium sulfate, and filtered through Celite. The
filtrate was concentrated to give an amine. The amine was dissolved
in dry THF (3.0 mL), then tert-butyl 4-nitrophenyl(2,6-diisopropyl-
1,4-phenylene)biscarbamate 33 (274 mg, 0.60 mmol) was added
to the solution, and the mixture was stirred at room temperature
for 1 h. The reaction was quenched by adding saturated NaHCO3
solution and extracted with EtOAc. The organic layer was washed
with saturated NaHCO3 solution, brine, and dried over anhydrous
magnesium sulfate. After filtration, the solvent was removed in va-
cuo, andtheresiduewaspurifiedbyaminosilicagelcolumnchroma-
tography to give urea as a white amorphous. The urea was added to
10% HCl–MeOH (5.0 mL) at room temperature, and the mixture was
stirred for 3 days. The solvent was removed in vacuo, and the result-
ingsolidwastrituratedwithiPrOH/Et2Otogive22(250 mg, 91%)asa
yellow solid. Mp 197–198 °C (dec.); 1H NMR (DMSO-d6, 60 °C,
300 MHz) d 1.09 (12H, d, J = 7.0 Hz), 2.33 (2H, m), 2.54 (2H, m),
3.05 (2H, m), 3.35 (2H, m), 3.56 (2H, s), 3.77 (2H, m), 3.81 (3H, s),
6.89 (1H, m), 6.99 (1H, m), 7.04 (1H, d, J = 8.0 Hz), 7.10 (2H, s), 7.33
(1H, dd, J = 8.0, 8.0 Hz), 7.37 (1H, m), 7.48 (2H, m), 7.68 (1H, s),
7.71(2H, m); 13C NMR (DMSO-d6, 75 MHz) d 22.9, 27.8, 30.1, 50.8,
54.8, 111.6, 112.4, 117.5, 118.3, 120.5, 123.8, 127.5, 129.2, 129.5,
130.0, 132.8, 143.6, 148.3, 156.7, 159.3; IR (ATR) 2964, 2600, 1655,
2241, 1591 cmꢀ1
; MS (ESI) m/z 294 (M+1). Anal. Calcd for
C18H19N3O: C, 73.69; H, 6.53; N, 14.32. Found: C, 73.30; H, 6.45;
N, 14.31.
5.1.16. 4-(3-Methoxyphenyl)-1-(3-methoxypyridin-2-
yl)piperidine-4-carbonitrile (18)
Compound 18 was prepared from 14 and 2-bromo-3-methoxy-
pyridine in a manner similar to that described for compound 15
with a yield of 97% as a yellow oil. 1H NMR (CDCl3, 300 MHz) d
2.18 (2H, m), 2.27 (2H, m), 3.29 (2H, m), 3.80 (3H, s), 3.85 (3H,
s), 4.12 (2H, m), 6.86 (2H, m), 7.04–7.12 (3H, m), 7.30 (1H, dd,
J = 8.0, 8.0 Hz), 7.88 (1H, dd, J = 4.9, 1.4 Hz); 13C NMR (CDCl3,
75 MHz) d 36.0, 42.8, 45.6, 55.0, 77.2, 111.6, 112.9, 117.1, 117.3,
117.6, 121.7, 129.8, 138.5, 141.6, 146.5, 151.2, 159.7; IR (ATR)
2233, 1601, 1587 cmꢀ1; HRMS (ESI) m/z Calcd for C19H21N3O2:
324.1707. Found: 324.1704 (
D
= ꢀ0.78 ppm).
5.1.17. 1-[3-(Benzyloxy)pyridine-2-yl]-4-(3-
methoxyphenyl)piperidine-4-carbonitrile (19)
Compound 19 was prepared from 14 and 2-bromo-3-benzyl-
oxypyridine24 in a manner similar to that described for compound
15 with a yield of 99% as a pale yellow oil. 1H NMR (CDCl3,
300 MHz) d 2.11 (2H, m), 2.21 (2H, m), 3.33 (2H, m), 3.81 (3H, s),
4.20 (2H, m), 5.09 (2H, s), 6.82 (1H, dd, J = 7.9, 4.8 Hz), 6.86 (1H,
m), 7.04–7.14 (3H, m), 7.31 (1H, dd, J = 8.0, 8.0 Hz), 7.32–7.44
(5H, m), 7.91 (1H, dd, J = 4.8, 1.4 Hz); 13C NMR (CDCl3, 75 MHz) d
36.2, 43.0, 45.8, 55.3, 70.5, 111.9, 113.0, 117.0, 117.8, 119.7,
121.9, 127.2, 128.1, 128.6, 129.9, 136.3, 139.4, 141.9, 145.7,
151.8, 159.9; IR (ATR) 2244, 1601, 1585 cmꢀ1; HRMS (ESI) m/z
1551 cmꢀ1
;
MS (ESI) m/z 515 (M+1). Anal. Calcd for
C32H42N4O2ꢁ2HClꢁ3/2H2O: C, 62.53; H, 7.71; N, 9.12. Found: C,
62.84; H, 7.55; N, 9.30.
5.1.20. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[1-(2-
methoxyphenyl)-4-(3-methoxyphenyl)piperidin-4-
Calcd
for
C25H25N3O2:
400.2020.
Found:
400.2015
(D
= ꢀ1.25 ppm).
yl]methyl}urea dihydrochloride (1)
Compound 1 was prepared from 7 in a manner similar to that
described for compound 22 with a yield of 90% as a pale yellow so-
lid (iPrOH/Et2O). Mp 238–240 °C (dec.); 1H NMR (DMSO-d6, 60 °C,
300 MHz) d 1.07 (12H, d, J = 6.7 Hz), 2.35 (2H, m), 2.50 (2H, m),
3.08 (2H, m), 3.52 (4H, m), 3.75 (5H, br), 3.81 (3H, s), 6.92 (1H,
dd, J = 8.0, 2.2 Hz), 7.01 (3H, m), 7.11 (2H, s), 7.23 (1H, d,
5.1.18. N-(2,6-Diisopropylphenyl)-N’-{[4-(3-methoxyphenyl)-1-
phenylpiperidin-4-yl]methyl}urea (21)
To a solution of 6 (146 mg, 0.50 mmol) in dry THF (3.0 mL) was
added lithium aluminum hydride (37.9 mg, 1.0 mmol), and the
mixture was stirred at reflux for 1 h, and quenched with NaOH

S. Asano et al. / Bioorg. Med. Chem. 17 (2009) 4636–4646
4643
J = 8.3 Hz), 7.36 (1H, dd, J = 8.0, 8.0 Hz), 7.44 (1H, m), 7.72 (1H, s),
8.02 (1H, d, J = 7.8 Hz); 13C NMR (DMSO-d6, 75 MHz) d 23.0, 27.8,
29.9, 49.1, 54.9, 55.9, 111.6, 112.7, 114.0, 117.5, 118.6, 121.0,
122.8, 129.3, 130.0, 130.2, 130.5, 132.8, 148.3, 151.9, 156.7,
159.4; IR (ATR) 2956, 2600, 1655, 1605, 1551 cmꢀ1; MS (ESI) m/z
545 (M+1). Anal. Calcd for C33H44N4O3ꢁ2HClꢁ3/2H2O: C, 61.48; H,
7.66; N, 8.69. Found: C, 61.36; H, 7.47; N, 8.74.
s), 6.84 (1H, dd, J = 8.1, 2.2 Hz), 6.95–7.05 (3H, m), 7.12 (3H, m),
7.24 (2H, m), 7.29 (1H, dd, J = 8.1, 8.1 Hz), 7.65 (1H, s); 13C NMR
(DMSO-d6, 75 MHz) d 22.9, 27.8, 32.5, 40.6, 47.2, 48.5, 54.7,
111.1, 112.9, 117.6, 118.8, 120.3, 121.5, 122.4, 125.1, 127.8,
129.1, 129.9, 133.0, 141.3, 146.0, 148.3, 156.6, 159.3; IR (ATR)
2956, 2600, 1655, 1604, 1558 cmꢀ1; MS (ESI) m/z 599 (M+1). Anal.
Calcd for C33H41F3N4O3ꢁ2HClꢁ4/5H2O: C, 57.78; H, 6.55; N, 8.17.
Found: C, 58.11; H, 6.50; N, 7.97.
5.1.21. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[1,4-bis(3-
methoxyphenyl)piperidin-4-yl]methyl}ureadihydrochloride (23)
Compound 23 was prepared from 8 in a manner similar to that
described for compound 22 with a yield of 86% as a pale yellow so-
lid (iPrOH/Et2O). Mp 195–196 °C (dec.); 1H NMR (DMSO-d6, 60 °C,
300 MHz) d 1.07 (12H, d, J = 7.0 Hz), 2.23 (2H, m), 2.44 (2H, m),
3.07 (2H, m), 3.25 (2H, m), 3.52 (2H, s), 3.69 (2H, m), 3.76 (3H,
s), 3.80 (3H, s), 6.82 (1H, d, J = 8.0 Hz), 6.87 (1H, dd, J = 8.0,
2.2 Hz), 6.97 (1H, s), 7.02 (1H, d, J = 8.0 Hz), 7.09 (2H, s), 7.14
(2H, m), 7.32 (1H, dd, J = 8.0, 8.0 Hz), 7.63 (1H, s); 13C NMR
(DMSO-d6, 75 MHz) d 23.0, 27.8, 30.5, 54.8, 55.2, 111.3, 111.4,
112.5, 117.4, 118.4, 120.0, 127.2, 129.2, 130.2, 131.8, 132.7,
135.7, 148.3, 156.7, 159.3, 159.9; IR (ATR) 2964, 2600, 1655,
5.1.25. N-(4-Amino-2,6-diisopropylphenyl)-N’-({4-(3-
methoxyphenyl)-1-[2-(2,2,2-trifluoroethoxy)phenyl]piperidin-
4-yl}methyl)urea dihydrochloride (27)
Compound 27 was prepared from 11 in a manner similar to that
described for compound 22 with a yield of 80% as a white solid
(iPrOH/Et2O). Mp 210–212 °C (dec.); 1H NMR (DMSO-d6, 60 °C,
300 MHz) d 1.07 (12H, d, J = 6.8 Hz), 2.28 (2H, br), 2.41 (2H, br),
3.08 (2H, m), 3.30 (2H, br), 3.45 (2H, br), 3.60 (2H, br), 3.79 (3H, s),
4.77 (2H, q, J = 8.6 Hz), 6.87 (1H, m), 6.97 (1H, s), 7.02 (1H, m), 7.11
(3H, m), 7.22–7.34 (3H, m), 7.65 (2H, br); 13C NMR (DMSO-d6,
75 MHz) d 22.9, 27.8, 30.9, 48.6, 54.7, 65.0, 65.5, 111.4, 112.6,
115.3, 117.5, 118.5, 122.8, 129.2, 130.0, 132.9, 148.3, 149.6, 156.6,
159.4; IR (ATR) 2964, 2602, 1655, 1605, 1558 cmꢀ1; MS (ESI) m/z
613 (M+1). Anal. Calcd for C34H43F3N4O3ꢁ2HClꢁH2O: C, 58.03; H,
6.73; F, 8.10; N, 7.96. Found: C, 58.35; H, 6.71; F, 7.69; N, 7.91.
1601, 1551 cmꢀ1
; MS (ESI) m/z 545 (M+1). Anal. Calcd for
C33H44N4O3ꢁ2HClꢁ3/2H2O: C, 61.48; H, 7.66; N, 8.69. Found: C,
61.47; H, 7.57; N, 8.89.
5.1.22. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[4-(3-
5.1.26. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[4-(3-
methoxyphenyl)-1-(4-methoxyphenyl)piperidin-4-
yl]methyl}urea dihydrochloride (24)
methoxyphenyl)-1-pyridin-2-ylpiperidin-4-yl]methyl}urea
dihydrochloride (28)
Compound 24 was prepared from 9 in a manner similar to that
described for compound 22 with a yield of 87% as a pale yellow so-
lid (iPrOH/Et2O). Mp 207–208 °C (dec.); 1H NMR (DMSO-d6, 60 °C,
300 MHz) d 1.07 (12H, d, J = 6.8 Hz), 2.32 (2H, m), 2.54 (2H, m),
3.06 (2H, m), 3.31 (2H, m), 3.56 (2H, s), 3.70(2H, m), 3.77 (3H, s),
3.81 (3H, s), 6.89 (1H, m), 7.05 (6H, m), 7.33 (1H, dd, J = 7.9,
7.9 Hz), 7.63 (1H, s), 7.68 (2H, d, J = 8.3 Hz); 13C NMR (DMSO-d6,
75 MHz) d 23.0, 27.8, 30.1, 51.6, 54.8, 55.4, 110.4, 111.6, 112.4,
114.7, 117.0, 118.2, 121.1, 122.1, 129.2, 130.8, 136.0, 148.3,
156.8, 158.7, 159.3; IR (ATR) 2964, 2569, 1653, 1602, 1558,
Compound 28 was prepared from 15 in a manner similar to that
described for compound 22 with a yield of 72% as a white solid
(iPrOH/Et2O). Mp 183–185 °C (dec.); 1H NMR (DMSO-d6, 60 °C,
300 MHz) d 1.07 (12H, d, J=6.8 Hz), 1.98 (2H, m), 2.15 (2H, m),
3.06 (2H, m), 3.39 (2H, m), 3.52 (2H, m), 3.79 (3H, s), 3.95 (2H,
m), 6.11 (1H, s), 6.82–6.90 (2H, m), 6.95 (1H, s), 7.01 (1H, d,
J = 7.9 Hz), 7.09 (2H, s), 7.31 (2H, m), 7.68 (1H, s), 7.89–7.97 (2H,
m); 13C NMR (DMSO-d6, 75 MHz) d 22.8, 23.7, 28.0, 31.7, 41.2,
43.1, 48.1, 54.9, 111.4, 112.1, 112.4, 113.0, 117.6, 118.9, 129.5,
130.1, 133.1, 137.3, 143.4, 145.2, 148.4, 151.8, 156.8, 159.4; IR
(ATR) 3284, 2590, 1639, 1603, 1541 cmꢀ1; MS (ESI) m/z 516
(M+1). Anal. Calcd for C31H41N5O2ꢁ2HClꢁ3/2H2O: C, 60.48; H,
7.53; N, 11.38. Found: C, 60.13; H, 7.47; N, 11.20.
1514 cmꢀ1
;
MS (ESI) m/z 545 (M+1). Anal. Calcd for
C33H44N4O3ꢁ2HClꢁ2H2O: C, 60.63; H, 7.71; N, 8.57. Found: C,
60.28; H, 7.63; N, 8.73.
5.1.23. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[1-(2-
methoxyphenyl)-4-phenylpiperidin-4-yl]methyl}urea
dihydrochloride (25)
5.1.27. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[4-(3-
methoxyphenyl)-1-pyridin-3-ylpiperidin-4-yl]methyl}urea
dihydrochloride (29)
Compound 25 was prepared from 3 in a manner similar to that
described for compound 22 with a yield of 86% as a white solid
(iPrOH/Et2O). Mp 220–222 °C (dec.); 1H NMR (DMSO-d6, 60 °C,
300 MHz) d 1.09 (12H, d, J = 6.8 Hz), 2.33 (2H, m), 2.50 (2H, m),
3.07 (2H, m), 3.48 (4H, br), 3.72 (5H, br), 7.03 (1H, dd, J = 7.9,
7.9 Hz), 7.06 (2H, s), 7.20 (1H, d, J = 8.1 Hz), 7.31 (1H, m), 7.37–
7.46 (5H, m), 7.70 (1H, s), 7.91 (1H, d, J = 7.7 Hz); 13C NMR
(DMSO-d6, 75 MHz) d 23.0, 27.7, 30.0, 48.9, 55.8, 113.9, 117.4,
121.0, 122.4, 126.1, 126.4, 128.3, 129.8, 130.2, 130.9, 132.7,
148.2, 151.9, 156.7; IR (ATR) 2962, 2580, 1654, 1558 cmꢀ1; MS
(ESI) m/z 515 (M+1). Anal. Calcd for C32H42N4O2ꢁ2HClꢁ2H2O: C,
61.63; H, 7.76; N, 8.98. Found: C, 61.32; H, 7.62; N, 8.92.
Compound 29 was prepared from 16 in a manner similar to that
described for compound 22 with a yield of 78% as a pale yellow so-
lid (iPrOH/Et2O). Mp 183–185 °C (dec.); 1H NMR (DMSO-d6, 60 °C,
300 MHz) d 1.07 (12H, d, J = 7.0 Hz), 1.96 (2H, m), 2.15 (2H, m),
3.06 (2H, m), 3.21 (2H, m), 3.37 (2H, d, J = 4.0 Hz), 3.63 (2H, m),
3.78 (3H, s), 6.11 (1H, br), 6.82 (1H, dd, J = 8.0, .2.2 Hz), 6.95 (1H,
d, J = 2.2 Hz), 7.00 (1H, d, J = 8.0 Hz), 7.29 (1H, dd, J = 8.0, 8.0 Hz),
7.70 (1H, s), 7.74 (1H, dd, J = 9.0, 5.3 Hz), 8.00 (1H, dd, J = 9.0,
2.6 Hz), 8.07 (1H, d, J = 5.3 Hz), 8.36 (1H, d, J = 2.6 Hz); 13C NMR
(DMSO-d6, 75 MHz) d 22.9, 23.7, 31.4, 40.9, 43.2, 54.9, 111.3,
113.1, 117.5, 119.0, 126.7, 127.0, 128.6, 128,7, 129.4, 130.3,
133.1, 145.2, 148.1, 148.4, 156.8, 159.4; IR (ATR) 3284, 2590,
1653, 1603, 1552 cmꢀ1; MS (ESI) m/z 516 (M+1). Anal. Calcd for
C31H41N5O2ꢁ2HClꢁ7/4H2O: C, 60.04; H, 7.56; N, 11.29. Found: C,
59.77; H, 7.50; N, 11.28.
5.1.24. N-(4-Amino-2,6-diisopropylphenyl)-N’-({4-(3-
methoxyphenyl)-1-[2-(trifluoromethoxy)phenyl]piperidin-4-
yl}methyl)urea dihydrochloride (26)
Compound 26 was prepared from 10 in a manner similar to that
described for compound 22 with a yield of 83% as a white solid
(iPrOH/Et2O). Mp 193–195 °C (dec.); 1H NMR (DMSO-d6, 60 °C,
300 MHz) d 1.09 (12H, d, J = 7.0 Hz), 2.04 (2H, m), 2.15 (2H, m),
2.89 (2H, m), 3.07 (2H, m), 3.19 (2H, m), 3.37 (2H, s), 3.78 (3H,
5.1.28. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[4-(3-
methoxyphenyl)-1-pyridin-4-ylpiperidin-4-yl]methyl} urea
dihydrochloride (30)
Compound 30 was prepared from 17 in a manner similar to that
described for compound 22 with a yield of 73% as a white solid

4644
S. Asano et al. / Bioorg. Med. Chem. 17 (2009) 4636–4646
(iPrOH/Et2O). Mp 208–210 °C (dec.); 1H NMR (DMSO-d6, 60 °C,
300 MHz) d 1.07 (12H, d, J = 6.8 Hz), 1.96 (2H, m), 2.14 (2H, m),
3.05 (2H, m), 3.38 (2H, d, J = 4.8 Hz), 3.43 (2H, m), 3.78 (3H, s),
3.88 (2H, m), 6.20 (1H, br), 6.84 (1H, dd, J = 8.0, 2.2 Hz), 6.95 (1H,
d, J = 2.2 Hz), 7.01 (1H, d, J = 8.0 Hz), 7.07 (2H, s), 7.16 (2H, d,
J = 7.7 Hz), 7.30 (1H, dd, J = 8.0, 8.0 Hz), 7.72 (1H, s), 8.16 (1H, d,
J = 7.7 Hz); 13C NMR (DMSO-d6, 75 MHz) d 22.9, 23.7, 28.0, 32.0,
41.4, 43.0, 54.9, 107.4, 111.4, 113.0, 117.4, 118.9, 129.5, 130.6,
132.8, 139.4, 145.2, 148.3, 156.2, 156.9, 159.4; IR (ATR) 3234,
2594, 1641, 1601, 1541 cmꢀ1; MS (ESI) m/z 516 (M+1). Anal. Calcd
for C31H41N5O2ꢁ2HClꢁ2H2O: C, 59.61; H, 7.58; N, 11.21. Found: C,
59.46; H, 7.47; N, 11.20.
5.1.31. tert-Butyl (4-{[({[4-(3-hydroxyphenyl)-1-(2-
methoxyphenyl)piperidin-4-yl]methyl}amino)carbonyl]-
amino}-3,5-diisopropylphenyl)carbamate (35)
Compound 35 was prepared from 4 in a manner similar to that
described for compound 34 with a yield of 76% as a pale yellow
amorphous. 1H NMR (DMSO-d6, 60 °C, 300 MHz) d 1.09 (12H, d,
J = 7.0 Hz), 1.48 (9H, s), 1.96 (2H, m), 2.06 (2H, m), 2.82 (2H, m),
3.05 (2H, m), 3.12 (2H, m), 3.34 (2H, d, J = 5.5 Hz), 3.77 (3H, s),
6.66 (1H, m), 6.83 (4H, m), 6.89 (2H, m), 7.15 (1H, dd, J = 7.6,
7.6 Hz), 7.20 (2H, s), 7.24 (1H, s), 8.93 (1H, s), 9.10 (1H, s); 13C
NMR (DMSO-d6, 75 MHz) d 23.2, 27.7, 28.0, 32.7, 40.3, 46.7, 48.7,
55.2, 78.5, 112.2, 112.7, 113.0, 117.1, 117.8, 120.7, 121.8, 127.2,
128.9, 137.9, 141.8, 146.2, 146.8, 151.9, 152.6, 157.0, 157.3; IR
(ATR) 3281, 1716, 1699, 1655, 1597, 1522 cmꢀ1; HRMS (ESI) m/z
5.1.29. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[4-(3-
methoxyphenyl)-1-(3-methoxypyridin-2-yl)piperidin-4-yl]-
methyl}urea dihydrochloride (31)
Calcd for C37H51N4O5 631.3854; found 631.3831 (
D
= ꢀ3.71 ppm).
Compound 31 was prepared from 18 in a manner similar to that
described for compound 22 with a yield of 80% as a pale yellow so-
lid (iPrOH/Et2O). Mp 201–203 °C (dec.); 1H NMR (DMSO-d6, 60 °C,
300 MHz) d 1.08 (12H, d, J = 7.0 Hz), 2.00 (2H, m), 2.18 (2H, m),
3.08 (2H, m), 3.38 (2H, m), 3.41 (2H, m), 3.45 (3H, s), 3.86 (2H,
m), 3.90 (3H, s), 6.14 (1H, s), 6.83 (1H, dd, J = 8.0, 2.0 Hz), 6.96
(1H, s), 7.02 (1H, d, J = 8.0 Hz), 7.04 (1H, dd, J = 7.5, 6.0 Hz), 7.11
(2H, s), 7.30 (1H, dd, J = 8.0, 8.0 Hz), 7.57 (1H, d, J = 7.5 Hz), 7.69
(1H, d, J = 6.0 Hz), 7.73 (1H, s); 13C NMR (DMSO-d6, 75 MHz) d
22.9, 23.7, 28.0, 32.3, 41.1, 45.4 54.9, 56.7, 111.3, 113.1, 115.6,
117.7, 119.0, 121.9, 129.4, 129.7, 130.1, 133.2, 145.4, 147.0,
147.5, 148.4, 156.9, 159.4; IR (ATR) 3284, 2590, 1647, 1599,
5.1.32. tert-Butyl (4-{[({[1-(3-hydroxypyridin-2-yl)-4-(3-
methoxyphenyl)piperidin-4-yl]methyl}amino)carbonyl]-
amino}-3,5-diisopropylphenyl)carbamate (36)
Compound 36 was prepared from 19 in a manner similar to that
described for compound 34 with a yield of 82% as a white amor-
phous. 1H NMR (DMSO-d6, 60 °C, 300 MHz) d 1.06 (12H, d,
J = 6.8 Hz), 1.47 (9H, s), 1.95 (2H, m), 2.06 (2H, m), 3.03 (2H, m),
3.11 (2H, m), 3.35 (2H, d, J = 5.5 Hz), 3.50 (2H, m), 3.76 (3H, s),
5.54 (1H, br), 6.67 (1H, dd, J = 7.7, 4.8 Hz), 6.80 (1H, d, J = 7.9 Hz),
6.90 (1H, s), 6.92 (1H, m), 6.98 (1H, dd, J = 7.7, 1.7 Hz), 7.18 (3H,
s), 7.26 (1H, dd, J = 7.9, 7.9 Hz), 7.63 (1H, dd, J = 4.8, 1.7 Hz), 8.93
(1H, s), 9.25 (1H, br); 13C NMR (DMSO-d6, 75 MHz) d 23.1, 27.7,
28.0, 32.3, 41.0, 43.8, 48.6, 54.6, 78.5, 110.8, 112.8, 113.0, 116.1,
118.7, 121.3, 127.2, 129.0, 137.1, 137.9, 143.7, 146.5, 146.7,
1552 cmꢀ1
;
MS (ESI) m/z 546 (M+1). Anal. Calcd for
C32H43N5O3ꢁ2HClꢁ3/4H2O: C, 60.80; H, 7.41; N, 11.08. Found: C,
60.61; H, 7.44; N, 11.02.
151.1, 152.6, 156.9, 159.1; IR (ATR) 1697, 1653, 1597, 1522 cm
ꢀ1
;
HRMS (ESI) m/z Calcd for C36H50N5O5 632.3806; found
= ꢀ2.70 ppm).
5.1.30. tert-Butyl (4-{[({[1-(2-hydroxyphenyl)-4-(3-
methoxyphenyl)piperidin-4-yl]methyl}amino)carbonyl]-
amino}-3,5-diisopropylphenyl)carbamate (34)
632.3789 (D
5.1.33. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[1-(2-
To
a
suspension of lithium aluminum hydride (253 mg,
hydroxyphenyl)-4-(3-methoxyphenyl)piperidin-4-yl]methyl}-
urea dihydrochloride (37)
6.7 mmol) in dry THF (40 mL) was added 12 (1.33 g, 3.3 mmol),
and the mixture was stirred at reflux for 1 h and quenched with
NaOH solution. The resulting mixture was stirred at room temper-
ature for 1 h, added anhydrous magnesium sulfate, and filtered
through Celite. The filtrate was concentrated to give an amine.
The amine was dissolved in dry THF (40 mL), added tert-butyl 4-
The urea 34 (158 mg, 0.25 mmol) was added to 10% HCl–MeOH
(5.0 mL) at room temperature, and the mixture was stirred for
3 days. The solvent was removed in vacuo, and the resulting solid
was triturated with iPrOH/Et2O to give 37 (139 mg, 92%) as a white
solid. Mp 216–218 °C (dec.); 1H NMR (DMSO-d6, 60 °C, 300 MHz) d
1.08 (12H, d, J = 7.0 Hz), 2.35 (2H, m), 2.50 (2H, m), 3.07 (2H, m),
3.51 (4H, m), 3.81 (3H, s), 3.85 (2H, m), 6.89 (1H, m), 6.99–7.09
(5H, m), 7.25 (1H, dd, J = 7.9, 7.9 Hz), 7.34 (1H, dd, J = 7.9, 7.9 Hz),
7.66 (1H, s), 7.85 (1H, d, J = 7.9 Hz); 13C NMR (DMSO-d6, 75 MHz)
d 23.0, 27.8, 29.9, 49.2, 54.8, 111.6, 112.5, 117.2, 117.7, 118.4,
119.4, 122.5, 128.8, 129.3, 130.0, 130.6, 132.5, 148.3, 150.3,
156.7, 159.4; IR (ATR) 2962, 2571, 1652, 1602, 1558 cmꢀ1; MS
(ESI) m/z 531 (M+1). Anal. Calcd for C32H42N4O3ꢁ2HClꢁ2H2O: C,
60.09; H, 7.56; N, 8.76. Found: C, 60.05; H, 7.49; N, 8.76.
nitrophenyl(2,6-diisopropyl-1,4-phenylene)biscarbamate
33
(1.83 g, 4.0 mmol), and stirred at room temperature for 1 h. The
reaction was then quenched by adding saturated NaHCO3 solution
and extracted with EtOAc. The organic layer was washed with sat-
urated NaHCO3 solution, brine, and dried over anhydrous magne-
sium sulfate. After filtration, the solvent was removed in vacuo,
and the residue was purified by amino silica gel column chroma-
tography to give urea (2.15 g) as a colorless amorphous. To a solu-
tion of the amorphous in MeOH (43 ml) was added 20% Pd(OH)2/C
(50% wet, 215 mg), and stirred at room temperature for 1 h under
hydrogen atmosphere (0.3 MPa). The reaction mixture was filtered
through Celite, and the filtrate was concentrated. The residue was
purified by silica gel column chromatography to give 34 (1.90 g,
5.1.34. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[1-(2-iso-
propoxyphenyl)-4-(3-methoxyphenyl)piperidin-4-yl]methyl}-
urea dihydrochloride (38)
To a solution of 34 (158 mg, 0.25 mmol) in dry N,N-dimethyl-
formamide (1.5 mL) were added cesium carbonate (122 mg,
90%) as
a
colorless amorphous. 1H NMR (DMSO-d6, 60 °C,
300 MHz) d 1.07 (12H, d, J = 6.8 Hz), 1.47 (9H, s), 2.00 (2H, m),
2.11 (2H, m), 2.78 (2H, m), 3.00 (2H, m), 3.05 (2H, m), 3.37
(2H, d, J = 5.5 Hz), 3.77 (3H, s), 6.66 (1H, m), 6.74–6.85 (4H, m),
6.91 (2H, m), 7.18 (2H, s), 7.19 (1H, s), 7.25 (1H, m), 8.47 (1H,
br), 8.92 (1H, s); 13C NMR (DMSO-d6, 75 MHz) d 23.1, 27.6, 27.9,
32.7, 40.3, 47.0, 48.3, 54.6, 110.8, 112.8, 113.0, 115.1, 118.6,
118.7, 119.1, 122.7, 129.0, 137.9, 140.1, 146.7, 147.9, 150.1,
152.6, 156.9, 159.2; IR (ATR) 3385, 1654, 1602 cmꢀ1; HRMS
(ESI) m/z Calcd for C37H51N4O5 631.3854; found 631.3832
0.38 mmol) and 2-propyl iodide (27.5 lL, 0.28 mmol), and the mix-
ture was stirred at 60 °C for 4 h. The reaction was quenched by
adding saturated ammonium hydrochloride solution and the mix-
ture was extracted with EtOAc. The organic layer was washed with
brine and dried over anhydrous magnesium sulfate. After filtration,
the solvent was removed in vacuo, and the residue was purified by
amino silica gel column chromatography to give 2-isopropoxyl
derivative (139 mg) as colorless oil. The 2-isopropoxyl derivative
was added to 10% HCl–MeOH (5.0 mL) at room temperature and
(D
= ꢀ3.42 ppm).

S. Asano et al. / Bioorg. Med. Chem. 17 (2009) 4636–4646
4645
stirred for 3 days. The solvent was removed in vacuo, and the
resulting solid was triturated with iPrOH/Et2O to give 38
(112 mg, 69%) as a white solid. Mp 226–228 °C (dec.); 1H NMR
(DMSO-d6, 60 °C, 300 MHz) d 1.08 (12H, d, J = 7.0 Hz), 1.09 (6H,
br), 2.40 (2H, m), 2.52 (2H, m), 3.08 (2H, m), 3.45 (2H, m), 3.57
(2H, m), 3.60 (2H, br), 3.81 (3H, s), 4.73 (1H, br), 6.88 (1H, dd,
J = 8.1, 2.2 Hz), 7.01 (3H, m), 7.09 (2H, s), 7.22 (1H, d, J = 8.4 Hz),
7.35 (2H, m), 7.66 (1H, s), 8.10 (1H, br); 13C NMR (DMSO-d6,
75 MHz) d 20.8, 23.0, 27.7, 29.8, 31.4, 33.8, 48.9, 54.8, 70.5,
111.6, 112.7, 115.1, 116.3, 117.3, 118.5, 120.4, 123.6, 129.4,
130.1, 132.6, 148.2, 150.1, 156.6, 159.5; IR (ATR) 2968, 2549,
1637, 1606, 1558 cmꢀ1; MS (ESI) m/z 573 (M+1). Anal. Calcd for
C35H48N4O3ꢁ2HClꢁ2H2O: C, 61.66; H, 7.98; N, 8.22. Found: C,
61.36; H, 7.91; N, 8.56.
130.7, 132.9, 148.3, 151.2, 157.0, 159.4; IR (ATR) 3307, 2598,
1655, 1605, 1579, 1545 cmꢀ1; MS (ESI) m/z 616 (M+1). Anal. Calcd
for C37H53N5O3ꢁ3HClꢁ3H2O: C, 57.03; H, 8.02; N, 8.99. Found: C,
56.85; H, 7.95; N, 8.97.
5.1.38. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[1-[2-(2-
hydroxyethoxy)phenyl]-4-(3-methoxyphenyl)piperidin-4-yl]-
methyl}urea dihydrochloride (42)
To a solution of 34 (158 mg, 0.25 mmol) in dry N,N-dimethyl-
formamide (1.5 mL) were added cesium carbonate (122 mg,
0.38 mmol) and 2-benzyloxyethylbromide (43.6 lL, 0.28 mmol),
and the mixture was stirred at 60 °C for 6 h. The reaction was
quenched by adding H2O, and the mixture was extracted with
EtOAc. The organic layer was washed with brine, and dried over
anhydrous magnesium sulfate. After filtration, the solvent was re-
moved in vacuo, and the residue was purified by amino silica gel
column chromatography to give 2-benzyloxyethoxy derivative
(159 mg) as colorless oil. To a solution of the 2-benzyloxyethoxy
derivative in MeOH (3.0 mL) were added 5 N HCl solution (1 drop)
and 20% Pd(OH)2/C (50% wet, 32 mg), and the mixture was stirred
at room temperature for 20 h under hydrogen atmosphere
(0.45 MPa). The reaction mixture was filtered through Celite, and
the filtrate was concentrated.The residue was purified by silica
gel column chromatography to give 2-hydroxyethoxy derivative
(120 mg) as a white amorphous. The 2-hydroxyethoxy derivative
was added to 10% HCl–MeOH (5.0 mL) at room temperature, and
stirred for 3 days. The solvent was removed in vacuo, and the
resulting solid was triturated with iPrOH/Et2O to give 42
(118 mg, 72%) as a white solid. Mp 206–208 °C (dec.); 1H NMR
(DMSO-d6, 60 °C, 300 MHz) d 1.08 (12H, d, J = 7.0 Hz), 2.34 (2H,
m), 2.55 (2H, m), 3.08 (2H, m), 3.49 (2H, m), 3.55 (2H, br), 3.67
(2H, br), 3.81 (3H, s), 4.00 (2H, br), 4.10 (2H, t, J = 4.6 Hz), 6.88
(1H, dd, J = 8.0, 2.2 Hz), 7.01 (3H, m), 7.09 (2H, s), 7.23 (1H, d,
J = 7.5 Hz), 7.34 (1H, dd, J = 8.0, 8.0 Hz), 7.40 (1H, m), 7.71 (1H, s),
7.96 (1H, d, J = 7.9 Hz); 13C NMR (DMSO-d6, 75 MHz) d 23.0, 27.8,
29.9, 49.3, 54.8, 59.0, 70.9, 111.6, 112.4, 114.6, 117.3, 118.3,
120.9, 122.5, 129.3, 130.1, 130.4, 132.5, 148.3, 151.4, 156.9,
159.4; IR (ATR) 3346, 2966, 2602, 1662, 1606, 1551 cmꢀ1; MS
(ESI) m/z 575 (M+1). Anal. Calcd for C34H46N4O4ꢁ2HClꢁ7/4H2O: C,
60.12; H, 7.64; N, 8.25. Found: C, 60.24; H, 7.33; N, 8.00.
5.1.35. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[1-(2-
butoxyphenyl)-4-(3-methoxyphenyl)piperidin-4-yl]methyl}-
urea dihydrochloride (39)
Compound 39 was prepared from 34 and 1-butyl iodide in a
manner similar to that described for compound 38 with a yield
of 92% as a pale yellow solid (iPrOH/Et2O). Mp 193–194 °C (dec.);
1H NMR (DMSO-d6, 60 °C, 300 MHz) d 0.88 (3H, t, J = 7.3 Hz), 1.08
(12H, d, J = 6.8 Hz), 1.30 (2H, br), 1.51 (2H, br), 2.39 (2H, m), 2.51
(2H, m), 3.08 (2H, m), 3.45 (2H, m), 3.56 (2H, m), 3.60 (2H, br),
3.81 (3H, s), 3.98 (2H, m), 6.89 (1H, m), 7.01 (3H, m), 7.10 (2H,
s), 7.21 (1H, d, J = 8.1 Hz), 7.36 (2H, m), 7.67 (1H, s), 8.07 (1H,
br); 13C NMR (DMSO-d6, 75 MHz) d 13.2, 18.4, 23.0, 27.7, 29.8,
29.9, 33.8, 49.0, 54.8, 68.4, 111.6, 112.6, 114.4, 117.3, 118.4,
120.7, 123.1, 129.3, 130.0, 130.3, 132.7, 148.2, 151.2, 156.6,
159.4; IR (ATR) 2960, 2568, 1653, 1606, 1558 cmꢀ1; MS (ESI) m/z
587 (M+1). Anal. Calcd for C36H50N4O3ꢁ2HClꢁ9/4H2O: C, 61.75; H,
8.13; N, 8.00. Found: C, 61.62; H, 8.01; N, 7.99.
5.1.36. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[1-[2-(3-
aminopropoxy)phenyl]-4-(3-methoxyphenyl)piperidin-4-yl]-
methyl}urea trihydrochloride (40)
Compound 40 was prepared from 34 and tert-butyl N-(3-bro-
mopropyl)carbamate in a manner similar to that described for
compound 38 with a yield of 57% as a pale yellow solid (iPrOH/
Et2O). Mp 203–205 °C (dec.); 1H NMR (DMSO-d6, 60 °C, 300 MHz)
d 1.07 (12H, d, J = 6.8 Hz), 2.00 (2H, m), 2.37 (2H, m), 2.53 (2H,
m), 2.90 (2H, m), 3.07 (2H, m), 3.47 (4H, m), 3.75 (2H, m), 3.81
(3H, s), 4.20 (2H, m), 6.17 (1H, br), 6.89 (1H, m), 7.02 (3H, m),
7.10 (2H, s), 7.24 (1H, m), 7.35 (2H, m), 7.77 (1H, s), 7.85 (1H,
br), 8.20 (3H, br); 13C NMR (DMSO-d6, 75 MHz) d 22.8, 23.6, 26.3,
28.0, 30.0, 35.8, 49.6, 55.0, 64.9, 65.8, 111.7, 112.9, 114.6, 117.7,
118.4, 121.3, 122.7, 129.6, 130.2, 133.0, 148.4, 151.2, 156.9,
159.4; IR (ATR) 3307, 2603, 1652, 1606, 1581, 1558 cmꢀ1; MS
(ESI) m/z 588 (M+1). Anal. Calcd for C35H49N5O3ꢁ3HClꢁ9/4H2O: C,
56.98; H, 7.72; N, 9.49. Found: C, 56.75; H, 7.63; N, 9.45.
5.1.39. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[1-[2-(3-
hydroxypropoxy)phenyl]-4-(3-methoxyphenyl)piperidin-4-yl]-
methyl}urea dihydrochloride (43)
Compound 43 was prepared from 34 and 3-benzyloxypropylbr-
omide in a manner similar to that described for compound 42 with
a yield of 76% as a white solid (iPrOH/Et2O). Mp 186–188 °C (dec.);
1H NMR (DMSO-d6, 60 °C, 300 MHz) d 1.08 (12H, d, J = 6.8 Hz), 1.68
(2H, br), 2.38 (2H, m), 2.50 (2H, m), 3.08 (2H, m), 3.43 (4H, br), 3.55
(2H, br), 3.76 (2H, br), 3.81 (3H, s), 4.09 (2H, m), 6.88 (1H, dd,
J = 8.1, 2.2 Hz), 7.00 (3H, m), 7.10 (2H, s), 7.20 (1H, d, J = 8.1 Hz),
7.33 (1H, dd, J = 8.1, 8.1 Hz), 7.39 (1H, dd, J = 7.5, 7.5 Hz), 7.68
(1H, s), 8.02 (1H, d, J = 7.5 Hz); 13C NMR (DMSO-d6, 75 MHz) d
23.0, 27.8, 30.0, 31.3, 49.2, 54.8, 57.1, 66.1, 111.5, 112.7, 114.3,
117.3, 118.4, 120.7, 122.8, 129.4, 130.1, 130.3, 132.7, 148.3,
151.5, 156.7, 159.5; IR (ATR) 3290, 2962, 2563, 1653, 1606,
5.1.37. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[1-{2-(3-
(dimethylamino)propoxy]phenyl}-4-(3-
methoxyphenyl)piperidin-4-yl]methyl}urea trihydrochloride
(41)
Compound 41 was prepared from 34 and 3-chloro-N,N-dimeth-
ylpropylamine hydrochloride in a manner similar to that described
for compound 38 with a yield of 36% as a pale yellow solid (iPrOH/
Et2O). Mp 193–195 °C (dec.); 1H NMR (DMSO-d6, 60 °C, 300 MHz) d
1.08 (12H, d, J = 6.8 Hz), 2.13 (2H, m), 2.26 (2H, m), 2.53 (2H, m),
2.70 (6H, s), 3.04 (2H, m), 3.20 (2H, m), 3.31 (2H, m), 3.50 (2H,
m), 3.73 (2H, m), 3.85 (3H, s), 4.17 (2H, m), 5.98 (1H, br), 6.88
(1H, d, J = 8.1 Hz), 7.01 (3H, m), 7.05 (2H, s), 7.18 (1H, m), 7.34
(2H, m), 7.65 (1H, s), 7.67 (1H, br), 10.66 (1H, br); 13C NMR
(DMSO-d6, 75 MHz) d 22.8, 23.3, 23.6, 28.0, 29.9, 41.8, 49.5, 53.6,
55.0, 66.1, 111.8, 112.4, 117.7, 118.2, 121.3, 123.2, 129.6, 130.2,
1558 cmꢀ1
;
MS (ESI) m/z 589 (M+1). Anal. Calcd for
C35H48N4O4ꢁ2HClꢁ2H2O: C, 60.25; H, 7.80; N, 8.03. Found: C,
60.05; H, 7.74; N, 8.05.
5.1.40. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[4-(3-
hydroxyphenyl)-1-(2-methoxyphenyl)piperidin-4-yl]methyl}-
urea dihydrochloride (44)
Compound 44 was prepared from 35 in a manner similar to that
described for compound 37 with a yield of 89% as a white solid
(iPrOH/Et2O). Mp 224–226 °C (dec.); 1H NMR (DMSO-d6, 60 °C,

4646
S. Asano et al. / Bioorg. Med. Chem. 17 (2009) 4636–4646
300 MHz) d 1.09 (12H, d, J = 6.8 Hz), 2.29 (2H, m), 2.48 (2H, m),
3.08 (2H, m), 3.48 (4H, br), 3.76 (5H, br), 6.77 (1H, m), 6.87 (2H,
m), 7.04 (1H, dd, J = 7.7, 7.7 Hz), 7.11 (2H, s), 7.21 (1H, d,
J = 7.7 Hz), 7.22 (1H, dd, J = 8.1, 8.1 Hz), 7.40 (1H, dd, J = 7.7,
7.7 Hz), 7.70 (1H, s), 7.93 (1H, d, J = 7.7 Hz); 13C NMR (DMSO-d6,
75 MHz) d 23.0, 27.8, 30.0, 48.9, 55.9, 113.2, 113.6, 113.9, 116.8,
117.4, 121.0, 122.5, 129.2, 130.0, 130.2, 130.7, 132.7, 148.3,
151.9, 156.8, 157.5; IR (ATR) 3215, 2580, 1655, 1603, 1554,
(2 ꢂ 106 cells/mL/well) were incubated in medium containing lip-
osomes, the 3H-oleic acid–BSA complex, and various concentra-
tions of the synthesized compounds for 24 h in a humidified
incubator (5% CO2) at 37 °C. Lipids were then extracted from the
cells with hexane/2-propanol (3:2, v/v). The organic solvent was
evaporated, and the cholesteryl 3H-oleate was isolated by thin-
layer chromatography. The band corresponding to cholesteryl 3H-
oleate was scraped and the radioactivity counted. The remaining
cellular protein was dissolved in 0.1 N NaOH. Protein concentra-
tion was determined by the method of Lowry et al.26
1508 cmꢀ1
;
MS (ESI) m/z 531 (M+1). Anal. Calcd for
C32H42N4O3ꢁ2HClꢁ3/2H2O: C, 60.94; H, 7.51; N, 8.88. Found: C,
60.97; H, 7.22; N, 8.96.
5.2.2. Measurement of hepatic low-density lipoprotein receptor
expression
5.1.41. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[4-[3-(3-
hydroxypropoxy)phenyl]-1-(2-methoxyphenyl)piperidin-4-yl]-
methyl}urea dihydrochloride (45)
HepG2 cells treated with the synthesized compound were lysed
with lysis buffer (125 mM Tris–HCl (pH 8.0), 2 mM CaCl2, 1% Triton
X-100, CompleteTM (Boehringer Ingelheim Co., Ltd, Ingelheim, Ger-
many)) and centrifuged.27 Immunoblot analysis was performed
using mouse monoclonal antibody against LDL-R (clone IgG-C7)
(PROGEN Biotechnik GmbH, Heidelberg, Germany).
Compound 45 was prepared from 35 and 3-benzyloxypropylbr-
omide in a manner similar to that described for compound 42 with
a yield of 44% as a pale yellow solid (iPrOH/Et2O). Mp 194–196 °C
(dec.); 1H NMR (DMSO-d6, 60 °C, 300 MHz)
d 1.09 (12H, d,
J = 7.0 Hz), 1.89 (2H, dt, J = 6.4, 6.4 Hz), 2.30 (2H, m), 2.50 (2H,
m), 3.09 (2H, m), 3.49 (4H, br), 3.58 (2H, t, J = 6.4 Hz), 3.75 (5H,
br), 4.10 (2H, t, J = 6.4 Hz), 6.88 (1H, dd, J = 8.0, 2.0 Hz) 7.01 (3H,
m), 7.09 (2H, s), 7.19 (1H, d, J = 7.5 Hz), 7.34 (1H, dd, J = 8.0,
8.0 Hz), 7.39 (1H, dd, J = 7.5, 7.5 Hz), 7.68 (1H, s), 7.91 (1H, d,
J = 7.5 Hz); 13C NMR (DMSO-d6, 75 MHz) d 23.0, 27.8, 30.1, 32.1,
48.9, 55.8, 57.2, 64.5, 112.1, 113.2, 113.9, 117.3, 118.4, 121.0,
122.4, 129.3, 129.8, 130.3, 131.0, 132.6, 148.3, 151.2, 156.7,
158.9; IR (ATR) 3300, 2576, 2654, 2606, 1556, 1500 cmꢀ1; MS
(ESI) m/z 589 (M+1). Anal. Calcd for C35H48N4O4ꢁ2HClꢁ5/2H2O: C,
59.48; H, 7.84; N, 7.93. Found: C, 59.69; H, 7.58; N, 9.96.
Acknowledgments
We are grateful to Ms. K. Bando for performing the elemental
analysis, and Ms. I. Taoka for recording MS spectra.
Supplementary data
Supplementary data associated with this article can be found, in
the online version, at doi:10.1016/j.bmc.2009.04.059.
References and notes
5.1.42. N-(4-Amino-2,6-diisopropylphenyl)-N’-{[1-[3-(3-
hydroxypropoxy)pyridin-2-yl]-4-(3-methoxyphenyl)piperidin-
4-yl]methyl}urea dihydrochloride (46)
1. Spector, A. A.; Mathur, S. N.; Kaduce, T. L. Prog. Lipid Res. 1979, 18, 31.
2. Suckling, K. E.; Stange, E. F. J. Lipid Res. 1985, 26, 647.
3. Field, F. J.; Salome, R. G. Biochim. Biophys. Acta 1982, 712, 557.
4. Heider, J. G.; Pickens, C. E.; Kelly, L. A. J. Lipid Res. 1983, 24, 1127.
5. Drevon, C. A.; Engelhorn, S. C.; Steinberg, D. J. Lipid Res. 1980, 21, 1065.
6. Khan, B.; Wilcox, H. G.; Heimberg, M. Biochem. J. 1989, 258, 807.
7. Cianflone, K. M.; Yasruel, Z.; Rodriguez, M. A.; Vas, D.; Sniderman, A. D. J. Lipid
Res. 1990, 31, 2045.
8. Brecher, P. I.; Chobanian, A. V. Circ. Res. 1974, 35, 692.
9. Day, A. J.; Proudlock, J. W. Atherosclerosis 1974, 19, 253.
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11. Endo, A. J. Lipid Res. 1992, 33, 1569.
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Ohashi, N. J. Cardiovasc. Pharmacol. 2006, 47, 322.
13. Milliat, F.; Ferezou, J.; Delhon, A.; Lutton, C. C. R. Acad. Sci. III 2001, 324, 229.
14. Asano, S.; Ban, H.; Kino, K.; Ioriya, K.; Muraoka, M. Bioorg. Med. Chem. Lett.
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15. Sera, A.; Takemura, T.; Inoue, Y.; Magara, Y.; Seguchi, K.; Goto, R. Nippon Kagaku
Zasshi 1970, 91, 494.
16. Thompson, D.; Reeves, P. J. Heterocycl. Chem. 1983, 20, 771.
17. Asano, S.; Ban, H. Heterocycles 2008, 75, 183.
18. Wolfe, J. P.; Wagaw, S.; Buchwald, S. L. J. Am. Chem. Soc. 1996, 118, 7215.
19. Ban, H.; Muraoka, M.; Ohashi, N. Tetrahedron 2005, 10081.
20. Ohnuma, S.; Muraoka, M.; Ioriya, K.; Ohashi, N. Bioorg. Med. Chem. Lett. 2004,
14, 1309.
Compound 46 was prepared from 36 and 3-benzyloxypropylbr-
omide in a manner similar to that described for compound 42 with
a yield of 49% as a pale yellow solid (iPrOH/Et2O). Mp 173–175 °C
(dec.); 1H NMR (DMSO-d6, 60 °C, 300 MHz)
d 1.07 (12H, d,
J = 6.8 Hz), 1.91 (2H, tt, J = 6.1, 6.1 Hz), 2.02 (2H, m), 2.19 (2H, m),
3.07 (2H, m), 3.40 (2H, s), 3.47 (2H, m), 3.58 (2H, t, J = 6.1 Hz),
3.79 (3H, s), 3.83 (2H, m), 4.18 (2H, t, J = 6.1 Hz), 6.14 (1H, s),
6.83 (1H, dd, J = 8.0, 2.0 Hz), 6.96–7.03 (2H, m), 7.04 (1H, dd,
J = 7.9, 5.3 Hz), 7.13 (2H, s), 7.30 (1H, dd, J = 8.0, 8.0 Hz), 7.60 (1H,
d, J = 7.9 Hz), 7.67 (1H, d, J = 5.3 Hz), 7.76 (1H, s); 13C NMR
(DMSO-d6, 75 MHz) d 22.9, 23.7, 28.0, 31.7, 32.4, 41.1, 45.5, 48.4,
54.9, 57.1, 66.6, 111.3, 113.1, 115.6, 117.8, 118.9, 122.5, 129.2,
129.5, 130.1, 133.2, 145.5, 146.7, 146.9, 148.4, 156.9, 159.4; IR
(ATR) 3284, 2598, 1653, 1628, 1599, 1551 cmꢀ1; MS (ESI) m/z
590 (M+1). Anal. Calcd for C34H47N5O4ꢁ2HClꢁ5/4H2O: C, 59.60; H,
7.58; N, 10.22. Found: C, 59.41; H, 7.58; N, 10.25.
21. ACD/LogP DB; ACD/labs, 8.00 Release Product Version 8.08.
22. Idoux, J. P.; Gupton, J. T.; McCurry, C. K.; Crews, A. D.; Jurss, C. D.; Colon, C.;
Rampi, R. C. J. Org. Chem. 1983, 48, 3771.
5.2. Biology
23. Li, C. C.; Adams, R. J. Am. Chem. Soc. 1935, 57, 1565.
24. Genin, M. J.; Poel, T. J.; Yagi, Y.; Biles, C.; Ajthaus, I.; Keiser, B. J.; Kopta, L. A.;
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L. J. Med. Chem. 1996, 39, 5267.
25. Miyazaki, A.; Rahim Aba Torab, M. A.; Ohta, T.; Morino, Y.; Horiuchi, S. Biochim.
Biophys. Acta 1992, 1126, 73.
5.2.1. Acyl-coenzyme A: cholesterol acyltransferase activity in
rat macrophages
The amount of cholesterol esterification (an estimate of whole-
cell ACAT activity) was determined by measuring incorporation of
an extracellular 3H-oleic acid-BSA complex into the intracellular
cholesteryl ester.25 Resident peritoneal rat macrophages
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