Quinolinesulfonamides of aryloxy-/arylthio-ethyl piperidines: Influence of an arylether fragment on 5-HT1A/5-HT7 receptor selectivity

Article abstract of DOI:10.1002/ardp.201200322

The solid-phase synthesis of a new series of 19 biomimetics of long-chain arylpiperazines, namely flexible quinoline sulfonamides of aryl(heteroaryl)oxy-/ heteroarylthio-ethyl 4-aminomethylpiperidines, is reported. Various structural modifications applied followed by biological evaluation for 5-HT_1A, 5-HT₆, and 5-HT₇ receptors gave further support of a possible replacement of arylpiperazine with aryloxy-/arylthio-ethyl derivatives of alicyclic amines and control of receptor selectivity upon diversification in the aryl(heteroaryl)oxy-/heteroarylthio-ethyl fragment. The solid-phase synthesis of a new series of 19 biomimetics of long-chain arylpiperazines is reported. Biological evaluation for 5-HT_1A, 5-HT₆, and 5-HT₇ receptors supported the possible replacement of the arylpiperazine with aryloxy-/arylthio-ethyl derivatives of alicyclic amines and the control of receptor selectivity upon diversification in the aryl(heteroaryl)oxy-/heteroarylthio-ethyl fragment.

Full text of DOI:10.1002/ardp.201200322

1
80
Arch. Pharm. Chem. Life Sci. 2013, 346, 180–188
Full Paper
Quinolinesulfonamides of Aryloxy-/Arylthio-ethyl Piperidines:
Influence of an Arylether Fragment on 5-HT /5-HT
Receptor Selectivity
1A
7
1
2
1
Katarzyna Grychowska , Krzysztof Marciniec , Vittorio Canale , Michał Szymiec ,
1
1
3
2
1
Grzegorz Glanowski , Grzegorz Satała , Andrzej Ma s´ lankiewicz , Maciej Pawłowski ,
3
Andrzej J. Bojarski , and Paweł Zajdel
1
1
Department of Medicinal Chemistry, Jagiellonian University Medical College, Krak o´ w, Poland
Department of Organic Chemistry, Medical University of Silesia, Sosnowiec, Poland
Department of Medicinal Chemistry, Institute of Pharmacology, Polish Academy of Sciences, Krak o´ w,
Poland
2
3
The solid-phase synthesis of a new series of 19 biomimetics of long-chain arylpiperazines, namely flexible
quinoline sulfonamides of aryl(heteroaryl)oxy-/heteroarylthio-ethyl 4-aminomethylpiperidines, is
reported. Various structural modifications applied followed by biological evaluation for 5-HT1A
,
5
-HT , and 5-HT receptors gave further support of a possible replacement of arylpiperazine with
6
7
aryloxy-/arylthio-ethyl derivatives of alicyclic amines and control of receptor selectivity upon
diversification in the aryl(heteroaryl)oxy-/heteroarylthio-ethyl fragment.
7
Keywords: 5-HT1A and 5-HT receptor affinity / Alicyclic amines / Arylpiperazine biomimetics / Quinoline sulfonamides /
Solid-phase synthesis
Received: August 11, 2012; Revised: December 14, 2012; Accepted: December 21, 2012
DOI 10.1002/ardp.201200322
Introduction
ible aryloxy-/arylthio-ethyl fragment, while in the part cor-
responding to the alkylene spacer of LCAP, different, partially
rigidified amines – 3-aminopyrrolidine, 4-aminopiperidine,
4-aminomethylpiperidine were introduced. It was further
presented that the affinity of compounds for the tested
monoamine receptors (5-HT1A, 5-HT , 5-HT , D ) depended
Among several classes of 5-HTR ligands, long-chain arylpiper-
azine (LCAP) derivatives have been successfully exploited as a
mold for the development of either multireceptor agents or
selective ligands [1–3]. Structural modifications in the aryl-
piperazine fragment, variation of the length of an alkylene
linker, as well as diversification of a kind of terminal frag-
ment were undertaken to refine the receptor affinity and
selectivity of the lead structures and were aimed at develop-
ment of agents with potential application in the treatment
of depression, anxiety, schizophrenia, obesity, pain, and
Alzheimer’s disease.
6
7
2
upon a type of a substituent in the aryloxy-/arylthio-ethyl
fragments, the distance between the basic nitrogen atom and
the amide/sulfonamide moiety, and finally the kind of amide/
sulfonamide fragment. As a consequence, a new class of 5-HT
7
receptor antagonists, namely arylsulfonamide derivatives of
aryloxyethyl- and arylthioethyl-piperidines and pyrrolidines,
was identified. Importantly, it showed that the flexible frag-
ments may serve as a valuable starting point for optimization
of different modes of selectivity [4].
Employing a parallel solid-phase synthesis integrated with
virtual combinatorial library design, and followed by multi-
step virtual screening procedure, allowed us to propose a new
concept of arylpiperazine biomimetics [4]. In this series of
compounds, arylpiperazine moiety was replaced with a flex-
Now we report on the design and synthesis of a new series
of quinolinesulfonamide derivatives of aryl(heteroaryl)oxy-/
heteroarylthio-ethyl 4-aminomethylpiperidines II. The struc-
tural modifications comprised introduction of different qui-
noline sulfamoyl fragments, to further extend exploration in
a group of azinesulfonamides [5, 6], variation of different
substituents in the phenyl ring of the aryloxy-/arylthio-ethyl
fragment, as well as replacement of the central phenyl ring of
Correspondence: Paweł Zajdel, Department of Medicinal Chemistry,
Jagiellonian University Medical College, Krak o´ w 30-688, Poland.
E-mail: pawel.zajdel@uj.edu.pl
Fax: þ48 12 620 54 05
ß 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Arch. Pharm. Chem. Life Sci. 2013, 346, 180–188
Arylpiperazine Biomimetics
181
the 5-HT1A and 5-HT receptor selectivity via introduction of
7
different aryl(heteroaryl)oxy-/heteroarylthio-fragments.
N
Y
O
O
S
S
N
z
N
Results and discussion
H
N
N
I
Chemistry
The synthesis of quinoline sulfonamide derivatives of
aryl(heteroaryl)oxy-/heteroarylthio-ethyl 4-aminomethylpi-
peridines was performed according to the elaborated solid-
supported method on a BAL-linker functionalized poly-
styrene resin [4]. It was preceded by the preparation of
respective building blocks: BB1-quinolinesulfonyl chlorides
N
H
N
z
O
O
II
z = 3, 6, 7, 8
Y = O, S
3
{1–4} (Fig. 2) and BB2-aryl(heteroaryl)oxyethyl bromides and
Figure 1. General structure of the quinolinesulfonamide derivatives
of LCAPs (I) and quinolinesulfonamides of the aryloxyethyl- and
arylthioethyl derivatives of 4-aminomethylpiperidine (II).
heteroarylthioethyl bromides 6{1–6} (Fig. 3), following pre-
viously described procedures [4, 7]. The latter were obtained
upon treatment of the respective phenol/thiol derivatives
with 1,2-dibromoethane, in refluxing acetone, in the pres-
ence of potassium carbonate (Scheme 1).
the aryloxy-/arylthioethyl fragment with a five-membered
heteroaromatic system. We chose the 4-aminomethylpiper-
idine central core to maintain a distance between the tertiary
nitrogen atom and the sulfonamide bond, corresponding to
the four-methylene linker present in the previously reported
azinesulfonamide derivatives of LCAP I (Fig. 1). Structure–
activity relationships in the designed class of derivatives
would give support for the possibility of exploration of a
new chemical space and designing of either selective or
The solid-phase work-flow began with the attachment of 1-
Boc-4-aminomethylpiperidine to the solid support by the one-
pot reductive amination (Scheme 2). The subsequent sulfo-
nylation of the secondary amine 2, with different quinoline-
2 2
sulfonyl chlorides 3{1–4}, in the presence of TEA in CH Cl ,
yielded resin-bound intermediates 4{1–4}. The selective Boc
removal without cleavage of the product from the acid-labile
linker was accomplished using a mixture of trimethylsilyl-
trifluoromethane sulphonate (TMSOTf) and 2,6-lutidine.
7
multireceptor 5-HT1A and 5-HT receptor ligands, and control
N
O
O
O
O
O
O
O
O
S
N
S
S
S
Cl
Cl
Cl
Cl
N
N
3
4
1
2
Figure 2. The diversity of quinolinylsulfonyl chlorides 3{1–4}.
O
O
NH
O
O
N
Br
Br
Br
F
1
2
3
O
O
O
N
S
Br
Br
B
r
S
S
4
5
6
Figure 3. The diversity of N-alkylating agents – aryl(heteroaryl)oxylethyl bromides 6{1–5} and heteroarylthioethyl bromides 6{6}.
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182
K. Grychowska et al.
Arch. Pharm. Chem. Life Sci. 2013, 346, 180–188
HX
Y
i
X
Y
Br
R
R
Scheme 1. The synthesis of aryl(heteroaryl)-
oxylethyl bromides 6{1–5} and heteroaryl-
thioethyl bromides 6{6}. Reagents and condi-
tions: (i) 1,2-dibromoethane, K CO , (CH ) CO,
2 3 3 2
KI, 608C, 48–72 h.
Z
Z
X = O, S
n
n
Y = CH, N
_
6
{1 5}
Z = CH, S
n = 1, 2
Phenyl: Z=Y=CH; n=2
Boc
Boc
N
O
N
i
ii
HN
m
N
H
S
N
O
O
_
1
2
4{1 4}
BAL-PS resin
iii
X
Y
N
NH
R
iv
m
N
Z
m
N
S
n
S
N
N
O
O
O
O
_
_
_
7
{1 4, 1 6}
5{1 4}
v
X = O, S
X
Y
N
Y = CH, N
Z = CH, S
R
H
N
m
O
Z
S
n
m = 3, 6, 7, 8
n = 1, 2
N
O
_
8
26
Phenyl: Z=Y=CH; n=2
Scheme 2. The solid-phase synthesis of quinolinesulfonamide derivatives of aryl(heteroaryl)oxy-/heteroarylthio-ethyl 4-aminomethyl-
piperidines. Reagents and conditions: (i) 1-Boc-4-aminomethylpiperidine, NaBH CN, 1% AcOH/DMF, 608C, 24 h; (ii) ArSO Cl 3{1–4},
3
2
TEA, CH
CH Cl (90:10 v/v), 2 h.
2
Cl
2
, RT, 2 ꢁ 2 h; (iii) TMSOTf, 2,6-lutidine, CH
2
Cl
2
, 2 ꢁ 30 min; (iv) alkylating agent 6{1–6}, DBU, KI, DMF, 608C, 24 h; (v) TFA/
2
2
3
by displacement of [ H]-8-OH-DPAT (187 Ci/mmol) for 5-
The obtained amine derivatives 5{1–4} were further alkyl-
ated with aryl(heteroaryl)oxyethyl bromides and heteroar-
ylthioethyl bromides 6{1–6} yielding the support-bound
products 7{1–4, 1–6}. The reaction was performed in DMF
at 608C for 24 h, using 1,8-diazabicyclo[5,4,0]undec-7-ene
3
3
HT1AR, [ H]-LSD (85.2 Ci/mmol for 5-HT
(39.2 Ci/mmol) for 5-HT R [4].
Each compound was tested in triplicate at 7–8 concen-
6
R, and [ H]-5-CT
7
ꢀ11
ꢀ4
trations (10 –10 M). The inhibition constants (K ) were
i
(
DBU) as a base. The treatment of compounds 7 with the
calculated from the Cheng-Prushoff equation [8]. Results were
expressed as means of at least two separate experiments.
mixture of trifluoroacetic acid/DCM (90:10 v/v) afforded
the final sulfonamides 8–26. These were chromatographically
purified after evaporation of the cleavage cocktail under Discussion
nitrogen flow.
We have previously reported on the synthesis and in vitro
In vitro pharmacology
Radioligand binding assays were employed for determining
the affinity and the selectivity profile of the synthesized
pharmacological evaluation of the arylamide and arylsulfo-
namide derivatives of aryloxyethyl- and arylthioethyl-piper-
idines and pyrrolidines as novel, potent monoaminergic
receptor ligands [4]. It was found, that within the evaluated
series of compounds, receptor affinity and selectivity highly
6
compounds for human serotonin 5-HT1AR, 5-HT R, 5-HT7bR,
all stably expressed in HEK293 cells. This was accomplished
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Arch. Pharm. Chem. Life Sci. 2013, 346, 180–188
Arylpiperazine Biomimetics
183
6 7
Table 1. The binding data of the library members 8–26 for 5-HT1A, 5-HT , and 5-HT receptors.
Compd
{BB1,BB2}
K
i
ꢂ SEM [nM]
5-HT
Ratio of 5-HT
7
versus 5-HT1A
5-HT1A
6
5-HT
7
8
9
{1,1}
{2,1}
{3,1}
{4,1}
{1,2}
{4,2}
{1,3}
{2,3}
{3,3}
{4,3}
{1,4}
{2,4}
{3,4}
{4,4}
{2,5}
{4,5}
{1,6}
{2,6}
{4,6}
2 ꢂ 0.3
2104 ꢂ 325
3908 ꢂ 410
5860 ꢂ 460
1337 ꢂ 95
902 ꢂ 54
2164 ꢂ 320
423 ꢂ 38
634 ꢂ 28
329 ꢂ 32
997 ꢂ 62
560 ꢂ 71
663 ꢂ 19
506 ꢂ 37
1420 ꢂ 73
1031 ꢂ 66
2699 ꢂ 617
3164 ꢂ 450
1283 ꢂ 93
1907 ꢂ 106
4 ꢂ 0.3
1445 ꢂ 117
5589 ꢂ 340
2100 ꢂ 303
839 ꢂ 54
879 ꢂ 32
1128 ꢂ 88
44 ꢂ 4
723
310
700
20
7
18 ꢂ 1.4
3 ꢂ 0.6
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
42 ꢂ 3
129 ꢂ 9
200 ꢂ 28
180 ꢂ 22
207 ꢂ 115
196 ꢂ 13
360 ꢂ 19
40 ꢂ 2
5
<1
<1
<1
<1
7
3
16
4
9
8
7
3
32 ꢂ 3
28 ꢂ 1
20 ꢂ 1
277 ꢂ 17
165 ꢂ 8
51 ꢂ 4
21 ꢂ 3
327 ꢂ 14
291 ꢂ 13
909 ꢂ 75
1042 ꢂ 151
147 ꢂ 11
118 ꢂ 13
161 ꢂ 14
18 ꢂ 2
60 ꢂ 4
101 ꢂ 14
126 ꢂ 5
22 ꢂ 1
38 ꢂ 4
47 ꢂ 4
3
–
–
a)
Clozapine
Olanzapine
143 ꢂ 11
3442 ꢂ 408
a)
5 ꢂ 0.7
185 ꢂ 21
a)
Standard drugs added as a reference.
depended on the type of substituent in aryloxyethyl- and
arylthioethyl-fragments. These findings opened the possibility
for exploration of the structural determinants enabling a
(K < 50 nM). Introduction of acetamide moiety in meta
i
position resulted in the derivatives 8–11 which were devoid
of 5-HT
that compounds substituted with an electron withdrawing
fluoro atom in meta-position displayed low affinity for 5-HT
7 i
affinity (K > 800 nM). Following our previous data,
7
control of the 5-HT1A and 5-HT binding profile.
In the present study, we evaluated the influence of
aryl(heteroaryl)oxy-/heteroarylthio-fragments on 5-HT1A and
7
receptors, it was found that a shift of the fluoro atom from
meta- to para-position (compounds 12, 13) was also not
preferential for binding to these sites. The latter result
remains in accordance with our previous observations in a
group of quinoline-sulfonamides of LCAP [5]. However, this is
in contrast to the observations described by Volk et al. [9],
who reported the 4-halogen substitution in the phenyl ring of
5
-HT receptor affinity and selectivity. All the newly synthes-
7
ized azinesulfonamide derivatives of 4-aminomethylpiperi-
dine differently substituted with aryl(heteroaryl)oxy-/
heteroarylthio-ethyl fragments were tested for their affinity
for 5-HT1A, 5-HT
–26 displayed high-to-low binding affinities for 5-HT1A
¼ 2–360 nM) and 5-HT (K ¼ 20–5589 nM) receptors
and moderate-to-low affinities for 5-HT ones (K
¼ 329–
860 nM).
Among the evaluated series, compounds 14–17 with the
phenyl substituent in ortho position of the phenyl ring in the
6 7
, and 5-HT receptors (Table 1). Compounds
8
(K
i
7
i
LCAPs as crucial structural feature determining 5-HT1A/5-HT
selectivity.
7
6
i
5
To further extend structural modification around the
aryloxy-/arylthio fragment, we decided to replace the central
phenyl ring with a five-member heterocycle (thiazole).
Noteworthy, phenylthiazole-2-thiol connected via ethylene
aryloxy-fragment displayed high affinity for 5-HT
7
receptors
S
N
S
N
N
N
H
N
z
S
S
S
N
O
O
2
2
2
4: z = 3
5: z = 6
6: z = 8
III
Figure 4. Arylthiazole derivative III and its quinolinesulfonamide extended analogs 24–26.
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184
K. Grychowska et al.
Arch. Pharm. Chem. Life Sci. 2013, 346, 180–188
spacer with dimethylamine III was previously disclosed by
for 5-HT receptors. On the other hand, an acetamide moiety
7
Thomson et al. [10] as potent 5-HT R ligands (Fig. 4).
7
in meta position turned out to be highly favorable for 5-HT1A
Extension of the compound III with quinolinesulfamoyl
moiety in the alicyclic amino fragment, aimed at introduc-
tion of additional H-bond and p–p interaction, decreased
7
and selectivity over 5-HT sites. It was further found that
replacement of phenyl ring with thiazole moiety in the
aryloxy/arylthioethyl fragment resulted in compounds
privileged for 5-HT1A receptors. The study showed that qui-
nolinesulfonamides of aryl(heteroaryl)oxy-/heteroarylthio-
derivatives of alicyclic amines may be regarded as new
valuable chemical group for development of diverse mono-
aminergic receptor ligands.
the affinity of compounds 24–26 for 5-HT
7
Rs. On the other
hand, this modification shifted the receptor preference for
5
-HT1A receptors (K ¼ 22–47 nM). Furthermore, replacement
i
of the sulfur atom (25, 26) with the oxygen one (22, 23) in the
arylether moiety additionally decreased the affinity for 5-HT7
receptors up to sixfold to sevenfold. This observation is in
contrary to our previous results where replacement of
the sulfur atom, connected with the phenyl ring, with an
oxygen one did not significantly influence the affinity for
Experimental
Chemistry
5
-HT
7
R [4].
Solution and solid-phase organic transformations and resin washes
were carried out at ambient temperature, unless indicated other-
wise. Organic solvents (from Aldrich and Chempur) were of reagent
grade and were used without purification. BAL linker MBHA-resin
(loading 1.1 mmol/g) was purchased from Iris Chemicals. The
reagents were from Aldrich and Alfa Aesar.
It was also previously found that in a group of aryloxy-/
arylthio-ethyl derivatives, compounds containing electron
donating substituents in the ortho position of the phenyl
ring displayed high affinity for 5-HT1AR, and thus mimicked
ortho-methoxyphenylpiperazine moiety, a well-known 5-HT1A
privileged structure. Such binding preference was observed
in the case of 18–21 containing the ortho-methoxy moiety
Analytical HPLC were run on a Waters Alliance HPLC
instrument, equipped with a ChromolithSpeedROD column
(
(
4.6 mm ꢁ 50 mm). Standard conditions were eluent system A
water/0.1% TFA), system B (acetonitrile/0.1% TFA). A flow rate of
conserved in 2,2-dimethyl-7-benzofuran (K
i
¼ 21–60 nM).
5
Detection was performed on a PDA detector.
mL/min and a gradient of (0–100)% B over 3 min were used.
Even better preference for 5-HT1A receptors displayed com-
pounds containing acetamide moiety in meta position of
aryloxyethyl fragment. Among them, compounds 8 and 10
1
H NMR spectra were recorded at 300 MHz (Varian BB 200
1
spectrometer) using TMS (0.00 ppm) and chloroform-d ; J values
are in Hertz (Hz), and splitting patterns are designated as follows:
s (singlet), bs (broad singlet), d (doublet), t (triplet), m (multiplet).
Melting points (mp) were determined with a B u¨ chi apparatus
and are uncorrected.
Elemental analysis for C, H, and N were carried out by a
micromethod using the Vario EI III elemental analyzer. The
results for elemental analyses were found within ꢂ0.4% of the
theoretical values.
showed the highest affinity for 5-HT1A receptors (K
i
¼ 2 and
3
nM, respectively) with acceptable selectivity over 5-HT
7
receptors (ꢃ700-fold).
Last but not least, it was further confirmed that in line with
our previous works, position of sulfonamide group in quino-
line moiety impacted the affinity of compounds for 5-HT1A
receptors; the rank order was as follows: 3-quinolinyl > 6-
quinolinyl > 8-quinolinyl. It is interesting that in the set of
LC/MS were carried out on a system consisting of a Waters
Acquity UPLC, coupled to a Waters TQD mass spectrometer.
All the analyses were carried out using a Acquity UPLC BEH
C18, 50 mm ꢁ 2.1 mm column, at 408C. A flow rate of
2
,2-dimethyl-7-benzofuranoxy derivatives, 7-quinoline sulfo-
namides displayed even higher affinity for 5-HT1A receptors
than the 3-quinolinyl counterpart. This fragment was
additionally the most preferential, in the set of biphenyl-
oxy (14–17) and 2,2-dimethyl-7-benzofuranoxy (18–21) deriva-
0
.3 mL/min and a gradient of (5–95)% B over 5 min was used.
Eluent A: water/0.1% HCO
Retention times (t ) are given in minutes. The UPLC/MS purity
2 2
H; eluent B: acetonitrile/0.1% HCO H.
R
of all the test compounds and key intermediates was determined
to be >96%.
tives, for 5-HT receptors. In the evaluated derivatives, local-
6
ization of sulfonamide group in the quinoline moiety has
marginally impacted the affinity for 5-HT sites [5].
7
Building blocks BB2 synthesis
General procedure for the synthesis of
Conclusions
aryloxylethylbromides derivatives 6{1–6}
A solution of 1,2-dibromoethane (0.02 mol) in 40 mL of acetone
was added dropwise into the mixture of respective phenol
Summing up, we described the synthesis and biological
evaluation of quinolinesulfonamide derivatives of aryl-
(0.08 mol) and
K
2
CO
3
(0.04 mol) in 30 mL of acetone.
Subsequently a catalytic amount of KI (0.3 mmol) was added
and the resulting mixture was stirred at 608C for 24–72 h.
After the completion of the reaction the inorganic residues were
filtrated off and organic mixture was concentrated under
vacuum. The obtained crude product was purified on silica gel
with EtOAc/hexane as eluting system.
(
heteroaryl)oxy-/heteroarylthio-ethyl 4-aminomethylpiperidines,
followed by determination of an influence of the aryl(hetero-
aryl)oxy-/heteroarylthio- fragment on 5-HT1A and 5-HT recep-
7
tor binding profile. Introduction of phenyl ring in ortho
position in the aryloxyethyl fragment confirmed preference
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Arch. Pharm. Chem. Life Sci. 2013, 346, 180–188
Arylpiperazine Biomimetics
185
1-(2-Bromoethoxy)-3-acetamidebenzene (6{1})
Obtained from 3-acetamidephenol, in 53% yield, as white solid,
Preparation of support-bound sulfonamide derivatives
One milliliter of a solution containing sulfonyl chloride
following chromatographic purification over silica gel with
1
([Diversity reagent 3, 3{1–4}] ¼ 0.40 mmol, 5 equiv, Fig. 2) in
EtOAc/n-hexane (8:2); t
CDCl
R
¼ 1.18; mp ¼ 92.4–93.08C. H NMR
2 2
CH Cl was added to the resin followed by addition of TEA
(
3
) d (ppm) 2.17 (s, 3H), 3.60–3.65 (t, 2H, J ¼ 5.4 Hz), 4.26–
.30 (t, 3H, J ¼ 7.4 Hz), 6.65–6.68 (m, 1H), 6.94–6.97 (m. 1H), 7.21–
.26 (m, 1H), 7.32 (m, 1H). Anal. (C10 12BrNO ) C, H.
(0.88 mmol, 11 equiv). The reactors were shaken for 2 h at room
temperature. The resin was drained and washed with DMF
4
7
H
2
(3 ꢁ 2 mL), MeOH (1 ꢁ 2 mL), and CH
2
Cl
under low vacuum. The procedure described above was repeated.
2
(3 ꢁ 2 mL), and dried
1-(2-Bromoethoxy)-4-fluorobenzene (6{2})
Obtained from 4-fluorophenol, in 60% yield, as colorless oil,
Boc-deprotection protocol
The resin was treated with 1 mL of a freshly prepared solution
following chromatographic purification over silica gel with
1
EtOAc/n-hexane (0.5:9.5); t
R
¼ 1.53. H NMR (CDCl
3
) d (ppm)
of TMSOTf (1.5 M) and 2,6-lutidine (1 M) in dry CH
The resin was shaken for 30 min and was washed with CH
2
Cl
Cl
2
.
3.60–3.64 (t, 2H, J ¼ 6.2 Hz), 4.23–4.28 (t, 2H, J ¼ 1.15 Hz),
2
2
6.83–6.89 (m, 2H), 6.94–7.01 (m, 2H). Anal. (C BrFO)
8
8
H
(3 ꢁ 1 mL). The reaction was repeated and the resin was washed
with CH Cl
(3 ꢁ 3 mL), DMF (3 ꢁ 3 mL), MeOH (5 ꢁ 3 mL), and
CH Cl
C, H.
-(2-Bromoethoxy)-2-phenylbenzene (6{3})
Obtained from 2-phenylphenol, in 69% yield, as white solid,
2
2
2
2
(3 ꢁ 3 mL), and dried under low vacuum. The efficacy of
the reaction was confirmed by a positive chloranil test.
1
following chromatographic purification over silica gel with
1
Alkylation with aryloxyalkylbromides and
arylthioalkylbromides
EtOAc/n-hexane (0.5:9.5); t
R
¼ 1.81; mp ¼ 66.7–67.38C. H NMR
(
CDCl
dd, 1H), 7.05–7.11 (td, 1H), 7.26–7.44 (m, 5H), 7.57–7.61 (m, 2H).
13BrO) C, H.
3
) d (ppm) 3.54–3.58 (t, 2H), 4.25–4.29 (t, 2H), 6.95–6.99
The deprotected resin 5 was swelled in CH
a 0.65 M solution of alkylating agent 6 ([diversity reagent 6,
{1–7}], 0.52 mmol, 6.5 equiv, Fig. 3) in DMF was added to the
2 2
Cl for 30 min,
(
Anal. (C14
H
6
resin, followed by addition of DBU (1.04 mmol, 13 equiv) and
KI (0.08 mmol, 1 equiv). The reactors were placed in 608C
for 24 h. The resulting resin 7 was drained, washed with DMF
7
-(2-Bromoethoxy)-2,2-dimethyl-2,3-dihydrobenzofuran
(6{4})
Obtained from 2,2-dimethyl-2,3-dihydrobenzofuran-7-ol, in 65%
yield, as colorless oil, following chromatographic purification
(
3 ꢁ 1 mL), MeOH (1 ꢁ 1 mL), CH
2
Cl
2
(3 ꢁ 1 mL) and dried
under vacuum.
1
over silica gel with EtOAc/n-hexane (0.5:9.5); t
CDCl
J ¼ 6.2 Hz), 4.35–4.43 (t, 2H, J ¼ 8.9 Hz), 6.75–6.81 (m, 3H). Anal.
15BrO ) C, H.
R
¼ 1.53. H NMR
(
3
) d (ppm) 1.50–1.55 (s, 6H), 3.02 (s, 2H), 3.60–3.65 (t, 2H,
Cleavage of the final products
A 1.5 mL of a mixture of TFA/CH Cl (9:1 v/v) was dispensed into
2 2
glass vials containing the resin. The cleavage was carried out
for 120 min, then the mixture was filtrated and the resin was
(
C
12
H
2
2 2
washed with a mixture of TFA/CH Cl (8:2 v/v), and the collected
filtrates were evaporated with a stream of argon on Eva parallel
evaporator.
Average overall yields of the crude products were between 38
and 57% and were calculated on the basis of the initial loading of
the resin. The LC/MS of the identified compounds 8–20 revealed
an average purity exceeding 82%. The crude residue was re-dis-
5-(2-Bromoethoxy)-2-phenylthiazole (6{5})
Obtained from 2-phenylthiazol-5-ol, in 59% yield, as white
solid, following chromatographic purification over silica with
1
EtOAc/n-hexane (9:1); t
CDCl
J ¼ 6.9 Hz), 5.99–6.02 (s, 1H), 7.32–7.37 (m, 2H), 7.43–7.50 (m, 3H).
Anal. (C11 10BrNOS) C, H.
R
¼ 1.47; mp ¼ 47.9–48.88C. H NMR
(
3
) d (ppm) 3.38–3.43(t, 2H, J ¼ 7.18 Hz), 4.04–4.09 (t, 2H,
H
2 2 2 2
solved in CH Cl or CH Cl /MeOH mixture, and purified using
2 2
silica gel columns and mixture CH Cl /MeOH, to elute the pure
products 8–20.
5-((2-Bromoethyl)thio)-2-phenylthiazole (6{6})
Obtained from 2-phenylthiazole-5-thiol, in 63% yield, as colorless
oil, following chromatographic purification over silica with
1
N-({1-[2-(3-Acetamidephenoxy)ethyl]piperidin-4-yl}methyl)-
quinoline-3-sulfonamide (8)
Yellow oil, 33 mg (46% yield) following chromatographic purifi-
cation over silica gel with EtOAc/MeOH (8:2); initial LC/MS purity
EtOAc/n-hexane (9:1); t
R
¼ 1.79. H NMR (CDCl
3
) d (ppm) 3.42–
3
7
.47 (t, 1H), 3.71–3.76 (t, 1H), 4.10–4.16 (t, 1H), 4.60–4.65 (t, 1H),
.15–7.19 (m, 1H), 7.22–7.28 (m, 2H), 7.38–7.47(m, 2H), 7.62–7.72
10BrNS ) C, H.
(
m, 1H). Anal. (C11
H
2
8
4
1
8%, t
R
¼ 1.05. C25
H
30
N
4
O
4
S, MW 482.60, monoisotopic mass
) d (ppm) 1.18–1.32 (m, 3H),
þ
1
82.20, [MþH] 483.4. H NMR (CDCl
3
Solid-phase synthesis on BAL-MBHA-PS-resin
Preparation of amine-bound resin 2 via reductive amination
The dried MBHA-BAL resin was placed in a reactor containing
.64–1.69 (m, 2H), 2.07–2.16 (s, 3H), 2.75–2.80 (t, 2H), 2.91–2.99
(m, 5H), 2.96–3.10 (m, 2H), 4.04–4.09 (t, 2H), 5.08 (bs, 1H), 6.60–
6
7
.64 (d, 1H), 6.93–6.96 (d, 1H), 7.14–7.19 (t, 1H), 7.26–7.34 (s, 1H),
.66–7.72 (t, 1H), 8.86–8.97 (m, 2H), 8.18–8.69 (d, 1H), 9.25 (m, 1H).
a
5
suspension of sodium cyanoborohydride ([NaBH
.5 mmol, 5 equiv) and the amine (5.5 mmol, 5 equiv), in 1%
3
CN] ¼
acetic acid in 15 mL of DMF. The reactor was placed in the oven
for 24 h at 608C. Then the resin was drained; washed with 10%
AcOH in DMF (1 ꢁ 15 mL), then with DMF (3 ꢁ 15 mL), MeOH
N-({1-[2-(3-Acetamidephenoxy)ethyl]piperidin-4-yl}methyl)-
quinoline-6-sulfonamide (9)
Yellow oil, 33 mg (46% yield) following chromatographic puri-
fication over silica gel with EtOAc/MeOH (8:2); initial LC/MS
(
1 ꢁ 15 mL), and CH
2
Cl
2
(3 ꢁ 15 mL), and dried under low
vacuum.
ß 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.archpharm.com

186
K. Grychowska et al.
Arch. Pharm. Chem. Life Sci. 2013, 346, 180–188
mass 501.21, [MþH]þ 502.4. H NMR (CDCl
1
purity 88%, t
R
¼ 1.05. C25
H
30
N
4
O
4
S, MW 482.60, monoisotopic
) d (ppm) 1.18–1.32
3
) d (ppm) 1.16–1.32
þ
1
mass 482.20, [MþH] 483.4. H NMR (CDCl
3
(m, 2H), 1.58–1.62 (m, 2H), 2.01–2.08 (t, 2H), 2.72–2.74 (m, 2H),
2.86–2.89 (m, 5H), 4.08–4.13 (t, 2H), 4.99 (bs, 1H), 6.92–6.95
(d, 1H), 7.01–7.06 (t, 1H), 7.26–7.39 (m, 5H), 7.47–7.50 (m, 2H),
7.66–7.71 (m, 1H), 7.86–7.91 (m, 2H), 8.21–8.30 (m, 1H), 8.68–8.69
(m, 1H), 9.24-9.25 (d, 1H).
(
m, 2H), 1.63–1.67 (m, 2H), 2.02–2.09 (m, 2H), 2.16 (s, 3H), 2.74–
2
5
7
8
.78 (t, 2H), 2.86–2.89 (m, 4H), 2.94–2.97 (m, 2H), 4.03–4.07 (t, 2H),
.29 (bs, 1H), 6.60–6.62 (d, 1H), 6.95–6.98 (d, 1H), 7.14–7.19 (t, 1H),
.46 (s, 1H), 7.52–7.56 (t, 1H), 8.04–8.08 (m, 1H), 8.2–8.29 (m, 2H),
.42–8.44 (d, 1H), 9.04–9.06 (m, 1H).
N-({1-[2-(Biphenyl-2-yloxy)ethyl]piperidin-4-yl}methyl)-
quinoline-6-sulfonamide (15)
Yellow oil, 42 mg (56% yield) following chromatographic puri-
N-({1-[2-(3-Acetamidephenoxy)ethyl]piperidin-4-yl}methyl)-
quinoline-7-sulfonamide (10)
Yellow oil, 33 mg (46% yield) following chromatographic puri-
fication over silica gel with EtOAc/MeOH (8:2); initial LC/MS
fication over silica gel with CH
purity 88%, t
2
Cl
S, MW 501.64, monoisotopic
) d (ppm) 1.16–1.32
2
/MeOH (9:1); initial LC/MS
R
¼ 1.27. C29
31 3 3
H N O
þ
1
purity 88%, t
R
¼ 1.05. C25
H
30
N
4
O
4
S, MW 482.60, monoisotopic
) d (ppm) 1.14–1.32
mass 501.21, [MþH] 502.4. H NMR (CDCl
3
þ
1
mass 482.20, [MþH] 483.4. H NMR (CDCl
3
(m, 2H), 1.58–1.62 (m, 2H), 2.01–2.08 (t, 2H), 2.79–2.87 (m, 5H),
2.93–2.97 (m, 2H), 4.08–4.13 (t, 2H), 4.99 (bs, 1H), 6.92–6.95
(d, 1H), 7.01–7.06 (t, 1H), 7.26–7.39 (m, 5H), 7.45–7.56 (m, 3H),
8.04–8.07 (m, 1H), 8.21–8.30 (m, 2H), 8.42 (m, 1H), 9.05–9.07
(d, 1H).
(
(
m, 2H), 1.63–1.67 (m, 2H), 2.16 (s, 3H), 2.74–2.78 (t, 2H), 2.86–2.89
m, 4H), 3.34–3.35 (m, 2H), 4.03–4.07 (t, 2H), 6.60–6.62 (d, 1H),
6
8
.95–6.98 (d, 1H), 7.14–7.19 (t, 1H), 7.46 (s, 1H), 7.52–7.56 (t, 1H),
.03–8.06 (m, 1H), 8.18–8.21 (m, 1H), 8.6–8.62 (m, 1H), 8.97–8.98
(
m, 1H), 8.97–8.98 (m, 1H), 11.8 (bs, 2H).
N-({1-[2-(Biphenyl-2-yloxy)ethyl]piperidin-4-yl}methyl)-
quinoline-7-sulfonamide (16)
Yellow oil, 42 mg (56% yield) following chromatographic puri-
N-({1-[2-(3-Acetamidephenoxy)ethyl]piperidin-4-yl}methyl)-
quinoline-8-sulfonamide (11)
Yellow oil, 30 mg (41% yield) following chromatographic puri-
fication over silica gel with CH
purity 88%, t
mass 501.21, [MþH] 502.4. H NMR (CDCl
2
Cl
S, MW 501.64, monoisotopic
) d (ppm) 1.16–1.25
2
/MeOH (9:1); initial LC/MS
fication over silica gel with CH
purity 88%, t
2
Cl
S, MW 482.60, monoisotopic
) d (ppm) 1.10–1.34
2
/MeOH (9:1); initial LC/MS
R
¼ 1.27. C29
31 3 3
H N O
þ
1
R
¼ 1.02. C25
H
30
N
4
O
4
3
þ
1
mass 482.20, [MþH] 483.4. H NMR (CDCl
3
(m, 2H), 1.58–1.62 (m, 2H), 1.94–2.02 (t, 2H), 2.72–2.74 (m, 2H),
2.86–2.89 (m, 5H), 4.08–4.13 (t, 2H), 4.99 (bs, 1H), 6.92–6.95
(d, 1H), 7.01–7.06 (t, 1H), 7.26–7.39 (m, 5H), 7.45–7.56 (m, 3H),
7.91–7.95 (m, 2H), 8.21–8.24 (m, 1H), 8.64–8.72 (m, 1H), 9.03–9.05
(m, 1H).
(
m, 3H), 1.66–1.71 (m, 2H), 2.01–2.12 (m, 2H), 2.16 (s, 3H), 2.79–
2
6
7
.81 (t, 2H), 2.87–3.02 (m, 4H), 4.06–4.23 (t, 2H), 5.08 (b s, 1H),
.60–6.64 (d, 1H), 6.93–6.95 (d, 1H), 7.15–7.20 (t, 1H), 7.34 (bs, 1H),
.65–7.73 (m, 1H), 7.85–7.92 (m, 1H), 7.93–7.97 (d, 1H), 8.16–8.22
(
d, 1H), 8.68–8.71 (d, 1H), 9.23–9.27 (d, 1H).
N-({1-[2-(Biphenyl-2-yloxy)ethyl]piperidin-4-yl}methyl)-
quinoline-8-sulfonamide (17)
Yellow oil, 41 mg (55% yield) following chromatographic puri-
N-({1-[2-(4-Fluorophenoxy)ethyl]piperidin-4-yl}methyl)-
quinoline-3-sulfonamide (12)
Yellow oil, 40 mg (60% yield) following chromatographic puri-
fication over silica gel with CH
purity 88%, t
mass 501.21, [MþH] 502.4. H NMR (CDCl
2
Cl
S, MW 501.64, monoisotopic
) d (ppm) 1.16–1.32
2
/MeOH (9:0.7); initial LC/MS
fication over silica gel with CH
¼ 1.18. C23
2
Cl
S, MW 443.53, monoisotopic
) d (ppm) 1.17–1.34
2
/MeOH (9:1); initial LC/MS
R
¼ 1.47. C29
31 3 3
H N O
þ
1
purity 88%, t
R
H
26FN
3
O
3
3
þ
1
mass 443.17, [MþH] 444.3. H NMR (CDCl
3
(m, 2H), 1.58–1.62 (m, 2H), 2.01–2.08 (t, 2H), 2.79–2.87 (m, 5H),
2.93–2.97 (m, 2H), 4.08–4.13 (t, 2H), 4.99 (bs, 1H), 6.92–6.95
(d, 1H), 7.01–7.06 (t, 1H), 7.26–7.39 (m, 5H), 7.45–7.56 (m, 3H),
8.04–8.07 (m, 1H), 8.21–8.30 (m, 2H), 8.42 (m, 1H), 9.05–9.07
(d, 1H).
(
m, 3H), 1.66–1.70 (m, 2H), 2.01–2.10 (t, 2H), 2.72–2.77 (t, 2H),
2.90–3.00 (m, 4H), 4.00–4.04 (t, 2H), 4.82 (bs, 1H), 6.78–6.84
(
8
m, 2H), 6.90–6.99 (m, 1H), 7.54–7.73 (t, 1H), 7.86–7.99 (m, 2H),
.18–8.21 (d, 1H), 8.69–8.70 (m, 1H), 9.25 (m, 1H).
N-({1-[2-(4-Fluorophenoxy)ethyl]piperidin-4-yl}methyl)-
quinoline-8-sulfonamide (13)
Yellow oil, 39 mg (59% yield) following chromatographic puri-
N-({1-[2-(2,2-Dimethyl-2,3-dihydrobenzofurane-7-yloxy)-
ethyl]piperidin-4-yl}methyl)quinoline-3-sulfonamide (18)
Yellow oil, 35 mg (47% yield) following chromatographic puri-
fication over silica gel with CH
¼ 1.18. C23
2
Cl
2
/MeOH (9:0.7); initial LC/MS
S, MW 443.53, monoisotopic
) d (ppm) 1.18–1.35
fication over silica gel with CH
purity 88%, t
2
Cl
S, MW 495.63, monoisotopic
) d (ppm) 1.23–1.29
2
/MeOH (9:1); initial LC/MS
purity 88%, t
R
H
26FN
3
O
3
R
¼ 1.32. C27
33 3 4
H N O
þ
1
þ
1
mass 443.17, [MþH] 444.3. H NMR (CDCl
3
mass 495.22, [MþH] ¼ 496.4. H NMR (CDCl
3
(
m, 3H), 1.68–1.73 (m, 2H), 2.01–2.11 (t, 2H), 2.70–2.75 (t, 2H),
(m, 2H), 1.48–1.49 (s, 7H), 1.65–1.69 (m, 2H), 2.02–2.09 (m, 4H),
2.76–2.80 (m, 4H), 2.90–3.00 (t, 2H), 4.13–4.17 (m, 2H), 6.70–6.77
(m, 2H), 7.67–7.73 (m, 1H), 7.87–7.92 (m, 1H), 7.95–7.98 (m, 1H),
8.18–8.21 (d, 1H), 8.69–8.70 (m, 2H), 8.43 (m, 1H), 9.25 (m, 1H).
2.90–3.00 (m, 4H), 4.02–4.04 (t, 2H), 4.84 (bs, 1H), 6.77–6.84
(
8
m, 2H), 6.90–6.99 (m, 1H), 7.54–7.73 (t, 1H), 7.86–7.99 (m, 2H),
.18–8.21 (d, 1H), 8.69–8.70 (m, 1H), 9.25 (m, 1H).
N-({1-[2-(Biphenyl-2-yloxy)ethyl]piperidin-4-yl}methyl)-
quinoline-3-sulfonamide (14)
N-({1-[2-(2,2-Dimethyl-2,3-dihydrobenzofurane-7-yloxy)-
ethyl]piperidin-4-yl}methyl)quinoline-6-sulfonamide (19)
Yellow oil, 42 mg (56% yield) following chromatographic puri-
fication over silica gel with CH
purity 88%, t
¼ 1.27. C29
Yellow oil, 37 mg (50% yield) following chromatographic puri-
fication over silica gel with CH
purity 88%, t
¼ 1.13. C27
2
Cl
2
/MeOH (9:1); initial LC/MS
S, MW 501.64, monoisotopic
2 2
Cl /MeOH (9:1); initial LC/MS
R
H
31
N
3
O
3
R
H
33
N
3
4
O S, MW 495.63, monoisotopic
ß 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.archpharm.com

Arch. Pharm. Chem. Life Sci. 2013, 346, 180–188
Arylpiperazine Biomimetics
187
þ
1
mass 495.22, [MþH] ¼ 496.4. H NMR (CDCl
3
) d (ppm) 1.21–1.40
m, 2H), 1.48–1.49 (s, 6H), 1.67–1.71 (d, 2H), 2.03–2.25 (m, 3H),
(m, 2H), 1.64–1.69 (m, 2H), 1.96–2.05 (t, 2H), 2.73–2.78 (t, 2H),
2.89–2.97 (m, 4H), 3.38–3.42 (t, 2H), 4.72–4.76 (m, 1H), 7.26–7.38
(m, 2H), 7.39–7.43 (m, 2H), 7.67–7.73 (t, 1H), 7.84–7.98 (m, 4H),
8.18–8.21 (d, 1H), 8.28–8.31 (m, 1H), 8.69–8.70 (m, 1H), 9.25
(m, 1H).
(
2
(
(
.82–2.95 (m, 4H), 3.00–3.08 (t, 4H), 4.14–4.18 (m, 2H), 4.89
bs, 1H), 6.70–6.78 (m, 3H), 7.53–7.57 (m, 1H), 8.04–8.08
m, 1H), 8.22–8.30 (m, 2H), 8.42–8.43 (d, 1H), 9.05–9.07 (m, 1H).
N-({1-[2-(2,2-Dimethylbenzofurane-7-yloxy)ethyl]-
piperidin-4-yl}methyl)quinoline-7-sulfonamide (20)
Yellow oil, 38 mg (51% yield) following chromatographic puri-
N-({1-[2-(4-Phenylthiazol-2-ylthio)ethyl]piperidin-4-yl}-
methyl)quinoline-6-sulfonamide (25)
Yellow oil, 32 mg (41% yield) following chromatographic puri-
fication over silica gel with CH
purity 88%, t
2
Cl
S, MW 495.63, monoisotopic
) d (ppm) 1.22–1.28
2
/MeOH (9:1); initial LC/MS
fication over silica gel with CH
2
Cl
2
/MeOH (9:0.3); initial LC/MS
, MW 524.72, monoisotopic
) d (ppm) 1.14–1.27
R
¼ 1.25. C27
H
33
N
3
O
4
purity 88%, t
mass 524.14, [MþH] ¼ 525.3. H NMR (CDCl
R
¼ 1.41. C26
28 4 2 3
H N O S
þ
1
þ
1
mass 495.22, [MþH] ¼ 496.4. H NMR (CDCl
3
3
(
m, 2H), 1.48 (s, 7H), 1.64–1.68 (m, 2H), 1.98–2.09 (m, 3H), 2.74–
(m, 2H), 1.64–1.68 (m, 2H), 1.95–2.03 (t, 2H), 2.73–2.82 (m, 2H),
2.86–3.04 (m, 4H), 3.37–3.49 (t, 2H), 4.66–4.70 (m, 1H), 7.26–7.39
(m, 2H), 7.40–7.43 (m, 2H), 7.53–7.57 (t, 1H), 7.84–7.89 (m, 2H),
8.04–8.08 (d, 1H), 8.22–8.30 (m, 2H), 8.43 (m, 1H), 9.05–9.07
2.78 (m, 2H), 2.89–3.00 (m, 5H), 4.11–4.15 (m, 2H), 4.88–4.89
(
(
m, 1H), 6.71–6.75 (m, 3H), 7.53–7.57 (m, 1H), 7.94–7.99
m, 2H), 8.22–8.25 (m, 1H), 8.64–8.65 (d, 1H), 9.04–9.05 (m, 1H).
(m, 1H).
N-({1-[2-(2,2-Dimethylbenzofurane-7-yloxy)ethyl]-
piperidin-4-yl}methyl)quinoline-8-sulfonamide (21)
N-({1-[2-(4-Phenylthiazol-2-ylthio)ethyl]piperidin-4-yl}-
methyl)quinoline-8-sulfonamide (26)
Yellow oil, 30 mg (38% yield) following chromatographic puri-
Yellow oil, 38 mg (51% yield) following chromatographic puri-
fication over silica gel with CH
2
Cl
2
/MeOH (9:1); initial LC/MS
S, MW 495.63, monoisotopic
purity 88%, t
R
¼ 1.25. C27
H
33
N
3
O
4
fication over silica gel with CH
2
Cl
2
/MeOH (9:1); initial LC/MS
, MW 524.72, monoisotopic
) d (ppm) 1.14–1.28
þ
1
mass 495.22, [MþH] ¼ 496.4. H NMR (CDCl ) d (ppm) 1.20–
.25 (m, 2H), 1.48 (s, 7H), 1.67–1.71 (m, 2H), 2.08–2.09 (m, 3H),
.67–2.71 (m, 2H), 2.97–3.00 (m, 5H), 4.14–4.18 (m, 2H), 6.41–
.45 (m, 1H), 6.71–6.75 (m, 3H), 7.53–7.57 (m, 1H), 7.94–
.99 (m, 2H), 8.22–8.25 (m, 1H), 8.64–8.65 (d, 1H), 9.04–9.05
3
purity 88%, t
R
¼ 1.39. C26
28 4 2 3
H N O S
þ
1
1
2
6
7
mass 524.14, [MþH] ¼ 525.3. H NMR (CDCl
3
(m, 2H), 1.64–1.69 (m, 2H), 1.94–2.01 (t, 2H), 2.67–2.76 (m, 5H),
2.90–2.93 (m, 2H), 3.38–3.42 (t, 2H), 7.26–7.43 (m, 5H), 7.64–7.69
(t, 1H), 7.84–7.87 (m, 2H), 8.05–8.08 (d, 1H), 8.28–8.31 (d, 1H),
8.42–8.45 (d, 1H), 9.00–9.02 (m, 1H).
(
m, 1H).
N-({1-[2-(4-Phenylthiazol-2-yloxy)ethyl]piperidin-4-yl}-
methyl)quinoline-6-sulfonamide (22)
Yellow oil, 35 mg (46% yield) following chromatographic puri-
Cell culture and preparation of cell membranes
HEK293 cells with stable expression of human serotonin
5
-HT1AR, 5-HT
Lipofectamine 2000) were maintained at 378C in a humidified
atmosphere with 5% CO and were grown in Dulbeco’s
6
R, and 5-HT7bR (prepared with the use of
fication over silica gel with CH
2
Cl
2
/MeOH (9:1); initial LC/MS
, MW 508.66, monoisotopic
) d (ppm) 0.90–
purity 88%, t
mass 508.16, [MþH] ¼ 509.1. H NMR (CDCl
R
¼ 1.17. C26
28 4 3 2
H N O S
2
þ
1
Modifier Eagle Medium containing 10% dialysed foetal
bovine serum and 500 mg/mL G418 sulfate. For membrane prep-
arations, cells were subcultured in 10 cm diameter dishes,
grown to 90% confluence, washed twice with prewarmed to
3
1
.04 (m, 2H), 1.50–1.54 (m, 2H), 1.64–1.79 (m, 3H), 2.35–2.39
t, 2H), 2.55–2.68 (m, 4H), 3.72–3.83 (t, 2H), 5.95 (s, 1H), 6.31–
.34 (t, 2H), 7.23–7.36 (m, 1H), 7.40–7.45 (m, 3H), 7.53–7.57
(
6
3
78C phosphate buffered saline (PBS) and pelleted by centrifu-
(
(
m, 1H), 8.04–8.08 (m, 1H), 8.22–8.30 (m, 2H), 8.42–8.43
d, 1H), 9.05–9.07 (m, 1H).
gation (200 g) in PBS containing 0.1 mM EDTA and 1 mM dithio-
threitol. Prior to membrane preparations pellets were stored
at ꢀ808C.
N-({1-[2-(4-Phenylthiazol-2-yloxy)ethyl]piperidin-4-yl}-
methyl)quinoline-8-sulfonamide (23)
Yellow oil, 32 mg (42% yield) following chromatographic puri-
Radioligand binding assays
Cell pellets were thawed and homogenized in 20 volumes of
assay buffer using an Ultra Turrax tissue homogenizer and
centrifuged twice at 35 000 g for 20 min at 48C with incubation
for 15 min at 378C in between. The composition of the assay
buffers was as follows: for 5-HT1AR: 50 mM Tris–HCl, 0.1 mM
fication over silica gel with CH
2
Cl
2
/MeOH (9:1); initial LC/MS
, MW 508.66, monoisotopic
) d (ppm) 0.92–1.06
purity 88%, t
R
¼ 1.17. C26
28 4 3 2
H N O S
þ
1
mass 508.16, [MþH] ¼ 509.1. H NMR (CDCl
3
(
m, 2H), 1.50–1.55 (m, 2H), 1.67–1.82 (m, 2H), 2.67–2.76 (m, 5H),
2.9–2.93 (t, 2H), 3.70–3.80 (t, 3H), 6.30–6.36 (t, 1H), 7.3–7.43
EDTA, 4 mM MgCl
-HT R: 50 mM Tris–HCl, 0.5 mM EDTA and 4 mM MgCl
for 5-HT7bR: 50 mM Tris–HCl, 4 mM MgCl , 10 mM pargyline,
2
, 10 mM pargyline and, 0.1% ascorbate; for
(
8
(
m, 3H), 7.54–7.58 (m, 1H), 7.64–7.69 (m, 1H), 7.55–7.69 (t, 2H),
.04–8.08 (m, 1H), 8.28–8.31 (m, 1H), 8.40–8.45 (m, 1H), 9.01–9.02
m, 1H).
5
6
2
, and
2
and 0.1% ascorbate. All assays were incubated in a total
volume of 200 mL in 96-well microtitre plates for 1 h at 378C
except for 5-HT1AR which were incubated at room temperature
for 1 h. The process of equilibration was terminated by
rapid filtration through Unifilter plates with a 96-well cell
harvester and radioactivity retained on the filters was quantified
on a Microbeta plate reader. For displacement studies the
N-({1-[2-(4-Phenylthiazol-2-ylthio)ethyl]piperidin-4-yl}-
methyl)quinoline-3-sulfonamide (24)
Yellow oil, 30 mg (38% yield) following chromatographic puri-
fication over silica gel with CH
2
Cl
2
/MeOH (9:1); initial LC/MS
, MW 524.72, monoisotopic
) d (ppm) 1.14–1.28
purity 88%, t
mass 524.14, [MþH] ¼ 525.3. H NMR (CDCl
R
¼ 1.39. C26
28 4 2 3
H N O S
þ
1
3
3
assay samples contained as radioligands: 1.5 nM [ H]-8-OH-DPAT
ß 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.archpharm.com

188
K. Grychowska et al.
Arch. Pharm. Chem. Life Sci. 2013, 346, 180–188
3
187 Ci/mmol) for 5-HT1AR; 2 nM [ H]-LSD (85.2 Ci/mmol) for
(
[3] M. Leopoldo, E. Lacivita, F. Berardi, R. Perrone, P. B.
Hedlund, Pharmacol. Ther. 2011, 129, 120–148.
3
5
-HT
Non-specific binding was defined with 10 mM of 5-HT in
-HT1AR and 5-HT R binding experiments, whereas 10 mM
R assay. Each compound
6
R; and 0.6 nM [ H]-5-CT (39.2 Ci/mmol) for 5-HT
7
R.
[
[
4] P. Zajdel, R. Kurczab, K. Grychowska, G. Satała, M. Pawłowski,
A. J. Bojarski, Eur. J. Med. Chem. 2012, 56, 348–360.
5
7
methiothepine was used in the 5-HT
was tested in triplicate at 7–8 concentrations (10 –10 M).
The inhibition constants (K ) were calculated from the Cheng–
6
5] P. Zajdel, K. Marciniec, A. Ma ´s lankiewicz, M. H. Paluchowska,
G. Satała, A. Partyka, M. Jastrz ˛e bska-Wi ˛e sek, D. Wr o´ bel,
A. Wesołowska, B. Duszy n´ ska, A. J. Bojarski, M. Pawłowski,
Bioorg. Med. Chem. 2011, 19, 6750–6759.
ꢀ11
ꢀ4
i
Prushoff equation [8]. Results were expressed as means of at
least three separate experiments. Membrane preparation and
general assay procedures for cloned receptors were adjusted
to 96-microwell format based on protocols described by us
previously [11, 12].
[
6] P. Zajdel, K. Marciniec, A. Ma ´s lankiewicz, G. Satała,
B. Duszy n´ ska, A. J. Bojarski, A. Partyka, M. Jastrz ˛e bska-
Wi ˛e sek, D. Wr o´ bel, A. Wesołowska, M. Pawłowski, Bioorg.
Med. Chem. 2012, 20, 1545–1556.
[
7] K. Marciniec, A. Ma ´s lankiewicz, M. Pawłowski, P. Zajdel,
This study was partly supported by the Funds for Statutory Activity
of Jagiellonian University Medical College. Radioligand binding
experiments were financially supported by the Norwegian Financial
Mechanism as part of the Polish-Norwegian Research Fund, grant no.
PNRF–103–AI-1/07.
Heterocycles 2007, 71, 1975–1990.
[8] Y. Cheng, W. H. Prusoff, Biochem. Pharmacol. 1973, 22, 3099–
3108.
[
9] B. Volk, J. Bark o´ czy, E. Hegedus, S. Udvari, I. Gacs a´ lyi,
T. Mezei, K. Pallagi, J. Med. Chem. 2008, 51, 2522– 2532.
The authors have declared no conflict of interest.
[10] C. G. Thomson, M. S. Beer, N. R. Curtis, H. J. Diggle, E.
Handford, J. J. Kulagowski, Bioorg. Med. Chem. Lett. 2004,
1
4, 677–680.
References
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Mokrosz, M. Ma ´c kowiak, S. Misztal, J. L. Mokrosz, Pharmazie
1993, 48, 289–294.
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1] M. L. L o´ pez-Rodr ´ı guez, D. Ayala, B. Benham u´ , M. J. Morcillo,
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[
12] M. H. Paluchowska, R. Bugno, B. Duszy n´ ska, E. Tatarczy n´ ska,
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ß 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.archpharm.com