Synthesis and evaluation of new arylsulfonamidomethylcyclohexyl derivatives as human neuropeptide Y Y 5 receptor antagonists for the treatment of obesity

Article abstract of DOI:10.1016/j.ejmech.2003.10.001

NPY is the most potent orexigenic peptide identified up to now. Stimulation of food intake is measured by the Y₁ and Y₅ receptor subtypes. In this study, the synthesis and evaluation of new arylsulfonamidomethylcyclohexyl derivatives are described as potential selective antagonists of the human NPY Y₅ receptor. The SAR of these series was examined and the amide derivatives were the compounds that showed the best activities. trans-N-{4-[(Quinolin-3-yl)aminocarbonyl]cyclohexylmethyl}- 2,4-dichlorobenzenesulfonamide (42) bound to the human neuropeptide Y Y ₅ receptor with a 2 nM IC₅₀.

Full text of DOI:10.1016/j.ejmech.2003.10.001

European Journal of Medicinal Chemistry 39 (2004) 49–58
www.elsevier.com/locate/ejmech
Original article
Synthesis and evaluation of new arylsulfonamidomethylcyclohexyl
derivatives as human neuropeptideYY5 receptor antagonists
for the treatment of obesity
Antonio Moreno, Silvia Pérez, Silvia Galiano, Laura Juanenea, Oihana Erviti,
Carmen Frígola, Ignacio Aldana *, Antonio Monge
Unidad en Investigación y Desarrollo de Medicamentos, Centro de Investigación en Farmacobiología Aplicada (CIFA),
Universidad de Navarra, c/Irunlarrea s/n, 31080 Pamplona, Spain
Received 26 June 2003; accepted 3 October 2003
Abstract
NPY is the most potent orexigenic peptide identified up to now. Stimulation of food intake is measured by theY1 andY5 receptor subtypes.
In this study, the synthesis and evaluation of new arylsulfonamidomethylcyclohexyl derivatives are described as potential selective antagonists
of the human NPY Y5 receptor. The SAR of these series was examined and the amide derivatives were the compounds that showed the best
activities. trans-N-{4-[(Quinolin-3-yl)aminocarbonyl]cyclohexylmethyl}-2,4-dichlorobenzenesulfonamide (42) bound to the human neu-
ropeptide Y Y5 receptor with a 2 nM IC50.
© 2003 Elsevier SAS. All rights reserved.
Keywords: Arylsulfonamide; Obesity; NPY; H NPY Y5 antagonists
1. Introduction
practically non-existence of efficient antiobesity drugs con-
verts the search for pharmacological treatment into a target of
notable interest [1,2].
Obesity treatments will be a leading problem in the 21st
century. Its prevalence is on the rise in all age groups and in
all of the developed countries throughout the world. The
exact etiology of obesity still remains unclear. It appears to
be caused mainly by a combination of genetic factors, inap-
propriate eating and reduced activity. In addition, deregula-
tion of various hypothalamic mechanisms controlling energy
intake and energy expenditure has also been implicated in
development and progression of obesity. In the past few
years, advances made in the understanding of the body’s
weight regulating mechanisms have helped to define novel
sites for targeting and intervention in order to reduce intake
and enhance expenditure. Based on the aforementioned,
many new antiobesity compounds have been described.
Some of them are in the early stages of development, and the
Today the role of neuropeptide Y in food intake behavior
is well recognized [3]. NPY is a protein made up of 36 amino
acids with an amide in carboxyterminal position (pancreatic
peptide family) found in abundance in the central and periph-
eral nervous system [4–7], whose alterations provoke eating
disorders (obesity, bulimia and anorexia nervosa), emotional
disorders (depression and anxiety), cardiovascular disorders
(hypertension), diabetes and other diseases [8].
Physiological processes in both the CNS and PNS have
been attributed to the activation of six receptor subtypes (Y1,
Y2, Y3, Y4, Y5 and Y6), members of the superfamily of
receptors linked to proteins G, with the Y1 and Y5 receptors
being responsible for appetite stimulation [9–12]. Therefore,
the enormous existing interest in the synthesis of new potent
NPY Y5 antagonists as antiobesity agents and the need to
clarify the important role that this neuropeptide plays in the
biology of food intake is more than justified.
This study proposes the search for new compounds that
possess antagonistic activity on receptorY5 through the syn-
thesis of new arylsulfonamidomethylcyclohexyl derivatives,
* Corresponding author.
E-mail address: ialdana@unav.es (I. Aldana).
© 2003 Elsevier SAS. All rights reserved.
doi:10.1016/j.ejmech.2003.10.001

50
A. Moreno et al. / European Journal of Medicinal Chemistry 39 (2004) 49–58
SO2
N
H
H
N
NH2
N
N
1. IC50=2.9 nM
CGP71683A
O
SO2
O
N
H
H
N
H
N
H
OH
SO2
N
O
N
H
H
3. IC50=9 nM
R. W. Johnson: DDR 2000, 22 (5)
2.IC50=0.11 nM
Shionogi: WO 0137826
Fig. 1. Antecedents.
due to the fact that the sulfonamide group and the cyclohexyl
linker were found to be essential in the concession of biologi-
cal activity [13]. Recently, new derivatives, which antagonize
the NPY Y5 receptor, have been published; all of them were
considered to be potential antiobesity agents due to their
notable in vitro activity (Fig. 1). Compound 1, CGP71683A,
reduces food intake in ob/ob rats and Zucker obese models
[14,15].
2. Chemistry
Synthesis has been carried out on a series of compounds
with a common nucleus, arylsulfonamidomethylcyclohexyl,
following the synthetic route shown in Scheme 1. The said
scheme presents both amide and amine derivatives as well as
N-formyl and (thio)urea derivatives for the optimization and
H2N
SO2
R
Cl
COOH
4
5
i. NaOH 2M
ii. HCl (c)
SO2
R
N
H
6
COOH
i.EDC
ii.R1-NH2
CH2Cl2
7
SO2
R
N
H
Amide derivatives
H
N
R1
8-50
O
BH4Na / AcH
Dioxane
SO2
N
H
Amine derivatives
H
N
51-54
R1
R2-NCX
POCl3
59
CH2Cl2
DMF
SO2
SO2
N
H
R1
N
O
N
H
H
N
N
R2
60-66
55-58
N-Formyl derivatives
Scheme 1. Synthesis of amide, amine, N-formyl and (thio)urea derivatives
R1
X
(Thio)urea derivatives

A. Moreno et al. / European Journal of Medicinal Chemistry 39 (2004) 49–58
51
Table 1
identification of compounds with high affinity to the human
IC50 (NPY Y5) results of the amide derivatives
Y5 receptor.
SO2
N
R
H
Amide derivatives 8–50 are first obtained by the formation
reaction of the primary sulfonamide intermediate 6, which
consists of a nucleophilic attack of amine 5 against sulfonyl
chloride 4 [16]. Finally, the acylation of the different amine
derivatives 7 required previous activation of the carboxylic
group 6 with 1-ethyl-3-(3′-dimethylaminopropyl)carbo-
diimide·HCl (EDC) [17].
The amine derivatives 51–54 are obtained from the start-
ing amides using the reaction medium BH4Na/AcH, which
yields the reducing agent sodium monoacetyloxy borohy-
dride, capable of reducing the amide group by means of a
transfer mechanism of hydrides [18]. Other reducing agents
(B2H6, BH3·Me2S, DIBAL, BH4Na/CH3SO3H, H4LiAl)
were used without success.
The N-formyl derivatives 55–58 are prepared from the
corresponding amine derivatives, using theVilsmeier reagent
as the formylating agent (POCl3/DMF).
The (thio)urea derivatives 60–66 are obtained by reacting
the corresponding amine derivatives with iso(thio)cyanates
59.
R1
O
IC50
IC50
C.
R
R1
C.
R
R1
(nM)
(nM)
8
>104
9
>104
>104
>104
>104
>104
748
HN
HN
HN
>104
>104
>104
>104
9240
11
13
15
17
19
OH
OH
10
12
14
16
18
HN
HN
N
N
O
N
OH
N
N
N
N
NO2
N
N
Cl
N
O
N
N
N
N
N
N
N
N
20
22
24
26
>104
>104
425
21
23
25
27
>104
>104
138
H3
C
N
N
N
N
N
N
N
N
N
N
N
N
F3C
CH3
CH3
SO2
N
N
N
N
N
N
N
Br
NO2
Cl
N
N
N
N
N
N
N
N
N
416
179
All of the compounds were chemically characterized by
thin layer chromatography (TLC), melting point, infrared,
nuclear magnetic resonance (1H NMR), elemental mi-
croanalysis and HPLC.
N
N
HN
28
30
19.2
335
29
31
>104
>104
N
N
NO2
HN
HN
>104
885
33
35
37
573
>104
106
HN
32
34
36
HN
HN
3. Pharmacology
Br
HN
Cl
N
Binding assays for both receptors NPY Y1 and NPY Y5
were carried out following the method described by Duhault
et al. [19]. For the human Y1 receptor binding assay, using
iodinated PeptideYY (NEN), incubations were performed at
30 °C for 90 min with various competitors’concentrations in
Buffer A (HEPES/NaOH 20 mM, pH 7.4, NaCl 10 mM,
KH2PO4 220 µM, CaCl2 1.26 mM, MgSO4 0.81 mM and
bovine serum albumin 0.1%) with SK-N-MC cell mem-
branes (50 µg of protein per ml of assay) in a total volume of
500 µl. Non-specific binding was determined in the presence
of 1 µM NPY. The reaction was then stopped by filtration, the
filters (GF/B, Whatman, precoated in 0.3% PEI) were exten-
sively washed with Buffer A, and counted in a gamma
counter (Packard). For humanY5 receptor binding assay, the
binding was carried out with iodinated peptideYY (NEN) as
follows: COS cells transfected with the human Y5 NPY
receptor were lysed and the membranes prepared by differ-
ential centrifugation. These membranes contained about
2 pmol per mg of protein of this receptor. Incubations were
performed in 500 µl comprising, 20 pM final of [125I]PYY in
50 µl, 400 µl of membrane suspension (0.15 mg ml–1) and
competitor dilutions in 50 µl, at 30 °C for 2 h. The reaction
was stopped by filtration through GF/C filters (Whatman).
The results in both assays are expressed in IC50 (Tables 1–4).
N
HN
HN
1910
N
HN
HN
HN
38
40
38.9
30.4
39
41
34.6
17.3
N
N
Br
N
Cl
F
Br
HN
HN
N
Cl
N
HN
>104
4220
NH
42
44
2.12
>104
43
45
N
Cl
NO2
N
N
N
HN
HN
S
S
S
N
HN
HN
46
>104
47
49
2840
79.9
S
N
N
N
HN
HN
HN
N
H
N
H
48
50
79.9
4.16
NO2
N
H
4. Results and discussion
Fifty-eight new compounds, derivatives of the arylsul-
fonamidomethylcyclohexyl nucleus, have been synthesized;
their affinities on the NPY Y1 and Y5 receptors have been
evaluated in vitro. The compounds presented show no an-

52
A. Moreno et al. / European Journal of Medicinal Chemistry 39 (2004) 49–58
Table 2
IC50 (NPY Y5) results of the amine derivatives
SO2
N
H
R1
Comp.
51
R1
IC50 (nM)
Comp.
52
R1
IC50 (nM)
>104
>104
HN
HN
53
>104
54
113
HN
HN
Table 3
IC50 (NPY Y5) results of the N-formyl derivatives
SO2
N
O
"
R1
H
Comp
55
R1
IC50 nM
Comp.
56
R1
IC50 nM
>104
>104
N
N
57
>104
58
n.d.
N
N
Table 4
IC50 (NPY Y5) results of the (thio)urea derivatives
SO2
N
H
H
N
R1
"
R2
X
Comp.
60
R1
R2
X
IC50 (nM)
N
N
N
N
O
10200
>105
>105
>105
>105
>105
>105
61
62
63
64
65
66
O
O
S
O
N
N
N
O
O
O
O
tagonistic activity on the Y1 receptor because their IC50
values are greater than 104 nM. The antagonistic activity of
the molecules on the NPYY5 receptor, shown in Tables 1–4,
will now be discussed.
The amide derivative results are shown in Table 1. Opti-
mization of this series led to the identification of compounds
with high affinity for the human Y5 receptor subtype. Three
lead compounds are obtained and referred to as 28, 42 and
50. The incorporation of more than one nitrogen atom in the
amine substituent R1 (16–28 and 35–50) of the amide deriva-
tives favors the appearance of antagonistic activity of these
compounds in comparison to other compounds that lack this

A. Moreno et al. / European Journal of Medicinal Chemistry 39 (2004) 49–58
53
heteroatom in their chains (8–15 and 29–34). In addition, the
said incorporation provides the molecule with the ability to
accept hydrogen bonds and with basicity related to the per-
meability of the hematoencephalic barrier.
pellets; the frequencies are expressed in cm–1. Signal inten-
sities are expressed by: s (strong), m (medium) and w (weak).
Elemental microanalyses were obtained on an Elemental
Analyzer (Carlo Erba 1106, Milan, Italy) from vacuum-dried
samples. The analytical results for C, H, and N, were
within 0.4 of the theoretical values.
The arylsulfonamide substituents R favor activity in the
cases of substitution in the ortho position on the benzene ring
(19, 22 vs. 24, 25; 29 vs. 30; 37, 39 vs. 40, 41), even more so
in cases of disubstitution ortho–para (42), or with condensa-
tion of the ring with another benzene, giving rigidness to the
molecule (19 vs. 26, 28). Substitution effects on R1 are
observed; they cause the chain to lengthen and become rigid,
thereby giving better antagonistic activity to the molecule
(31 vs. 33; 35 vs. 37). In conclusion, compounds that contain
rigid groups with basic moieties give greater affinity to the
antagonist.
Alugram® SIL G/UV254 (Layer: 0.2 mm) (Macherey-
Nagel GmbH & Co., KG, Postfach 101352, D-52313 Düren,
Germany) was used for TLC and Silica gel 60 (0.040–
0.063 mm) for Column Chromatography (Merck). HPLC
conditions: Column Lichrospher 100 RP18 E.C. 5 µm (20 ×
0.46), Ref. TR011567, NS N23892; mobile phase:
MeOH/H2O 60/40; flux: 1 ml min–1.
Chemicals were purchased from E. Merck (Darmstadt,
Germany), Scharlau (F.E.R.O.S.A., Barcelona, Spain), Pan-
reac Química S.A. (Montcada i Reixac, Barcelona, Spain),
Sigma-Aldrich Química, S.A., (Alcobendas, Madrid), Acros
Organics (Janssen Pharmaceuticalaan 3a, 2440 Geel, België)
and Lancaster (Bischheim-Strasbourg, France).
The preliminary results show that the amine derivatives
51–54 (Table 2), N-formyl derivatives 55–58 (Table 3) and
urea and thiourea derivatives 60–66 (Table 4) do not improve
the results of the amide derivatives to a significant degree.
6.2. General procedure for the synthesis of trans-4-(R-sul-
fonylaminomethyl)cyclohexanecarboxylic acid (6)
5. Conclusion
A solution of R-sulfonyl chloride (47.70 mmol) in the
minimum amount of CHCl3 was added, alternately and por-
This study shows new arylsulfonamidomethylcyclohexyl
derivatives as antagonistic agents of the NPY Y5 receptor.
The compounds are characterized by their selectivity on the
Y5 receptor as they show no affinity on the receptor Y1.
The amide derivatives possess good results of IC50, with
activities that reach a nanomolar level (compounds 28, 42
and 50 stand out). They are characterized by possessing rigid
moieties and basic centers capable of accepting hydrogen
bonds, containing an amide group, and having electron-
withdrawing substituents on the benzene ring of the arylsul-
fonamide group. These factors could orientate the arylsul-
fonamide, the linker cyclohexane, and the amine group
correctly in the Y5 receptor binding pockets.
tionwise, to
a
solution of trans-4-(aminomethyl)-
cyclohexanecarboxylic acid (5.0 g, 31.80 mmol) in NaOH
2 M (150 ml), with stirring for 30 min. After the addition, the
mixture was stirred at room temperature for 48 h. The aque-
ous layer was acidified with HCl (c) to pH 1–2. The residue
obtained was filtered and washed with H2O (5 × 20 ml) and
n-hexane (5 × 20 ml) in order to obtain sulfonamides 6.
6.2.1. Synthesis of trans-4-(benzenesulfonylaminomethyl)
cyclohexanecarboxylic acid
From benzenesulfonyl chloride (6.11 ml, 47.70 mmol) to
obtain the compound as a white solid (3.46 g, 24%); m.p.
160–162 °C; IR (KBr): m 1698 (s, carboxylic acid C=O),
1326 and 1162 (s, SO2–N) cm–1; 1H NMR (DMSO-d6,
400 MHz) d: 0.80–0.84 (m, 2H, Ha of CH–CH2–CH2–CH–
CO); 1.09–1.27 (m, 3H, Ha of CH–CH2–CH2–CH–CO);
1.69 (d, 2H, He of CH–CH2–CH2–CH–CO, JHe = 12.2 Hz);
1.84 (d, 2H, He of CH–CH2–CH2–CH–CO, JHe = 12.2 Hz);
2.06 (t, 1H, CH–CH2–CH2–CH–CO, J = 11.8 Hz); 2.56 (d,
2H, SO2–NH–CH2, JCH2–NH = 6.3 Hz); 7.58–7.61 (m, 4H,
H3, H4 and H5 of C6H5 and SO2–NH); 7.78 (d, 2H, H2 and
H6 of C6H5, J2.6–3.5 = 8.0 Hz); 12.00 (s, 1H, COOH). Anal.
C14H19NO4S (C, H, N); Mr 297.
The amine, N-formyl and (thio)urea derivatives do not
present activity, or in the cases in which they do, the results
are not within the range of nanomolar activity that our group
is interested in (<75 nM).
6. Experimental protocols
6.1. General
Melting points were determined with a Mettler FP82 +
FP80 apparatus (Greifense, Switzerland) and have not been
corrected. The 1H NMR spectra were recorded on a Bruker
400 Ultrashield™, using TMS as the internal standard and
with DMSO-d6 as the solvent; the chemical shifts are re-
ported in ppm (d) and coupling constants (J) values are given
in Hertz (Hz). Signal multiplicities are represented by: s
(singlet), ws (wide singlet), d (doublet), dd (double doublet),
t (triplet), m (multiplet) and the IR spectra were performed on
a Perkin Elmer 1600 FTIR (Norwalk, CT, USA) in KBr
The rest of the sulfonamides were prepared similarly
(Table 5).
6.3. General procedure for the synthesis of trans-N-
[4-(R1-ylaminocarbonyl) cyclohexylmethyl]-R-sulfonamide
(8–50)
Sulfonamides 6 (1 equiv.) in dry CH2Cl2 (150 ml) at 0 °C,
under N2 atmosphere, were treated with EDC (1.13 equiv.).

54
A. Moreno et al. / European Journal of Medicinal Chemistry 39 (2004) 49–58
Table 5
Sulfonamide compounds
SO2
N
H
R
OH
O
Comp.
6.a
R
Com
p.
R
Comp.
6.c
R
Br
6.b
Br
CH3
NO2
SO2
H3C
6.d
6.g
6.e
6.h
6.f
6.i
6.l
CH3
N
F3C
Cl
6.j
6.k
6.n
Cl
Cl
F
6.m
Cl
After 1 h at 0 °C, the corresponding amine 7 (1.13 equiv.) was
added. The reaction was stirred at room temperature for 24 h.
The solvent was evaporated and the residue was taken up
with H2O (20 ml) and diethyl ether (5 ml). The obtained
precipitate was filtered and washed with H2O (5 × 20 ml) and
diethyl ether (1 × 10 ml) in order to obtain compounds 8–50.
When necessary, the compounds were purified by means of
recrystallization with i-PrOH:H2O or by column chromatog-
raphy (CH2Cl2 to CH2Cl2/MetOH).
6.4. General procedure for the synthesis of trans-N-[4-
(R1-ylaminomethyl)cyclohexylmethyl]benzenesulfonamide
(51–54
)
Compounds 8, 12, 31, 33 (1 equiv., 0.75 g) in dry dioxane
(30 ml) under anhydrous conditions were mixed with BH4Na
(5 equiv.) at 0 °C. A mixture of dioxane (10 ml) and glacial
acetic acid (5 equiv.) was added over a period of 10 min at
10 °C. The resulting mixture was stirred under reflux for 5 h
and concentrated to dryness in vacuo. The excess reagent was
decomposed with water and extracted with chloroform. The
extract was evaporated in vacuo and the residue was col-
lected with n-hexane. The precipitate obtained was filtered in
order to obtain compounds 51–54.
6.3.1. Synthesis of trans-N-[4-(phenylaminocarbonyl)
cyclohexylmethyl]benzene sulfonamide (31)
From
trans-4-(benzenesulfonylaminomethyl)cyclo-
hexanecarboxylic acid (5.05 mmol, 1.50 g), EDC
(5.71 mmol, 1.09 g) and aniline (5.71 mmol, 0.53 g)
to obtain 31 as a white solid (1.00 g, 53%). m.p. 230–231 °C.
IR (KBr): m 1666 (s, amide C=O); 1311 and 1156 (s, SO2–N).
1H NMR (DMSO-d6, 400 MHz) d: 0.83–0.94 (m, 2H, Ha of
CH–CH2–CH2–CH–CO); 1.31–1.42 (m, 3H, Ha of
CH–CH2–CH2–CH–CO); 1.62–1.90 (m, 4H, He of
CH–CH2–CH2–CH–CO); 2.17–2.22 (m, 1H, CH–CH2–
CH2–CH–CO); 2.60 (t, 2H, SO2–NH–CH2, JCH2–
NH = 5.9 Hz); 7.00 (t, 1H, H4 of NH–C6H5, JH4–
H3,5 = 7.3 Hz); 7.26 (t, 2H, H3 and H5 of NH–C6H5, JH3,5–
H4 = 7.3 Hz); 7.56–7.62 (m, 6H, H3, H4, and H5 of C6H5, H2
and H6 of NH–C6H5 and SO2–NH); 7.78–7.82 (m, 2H, H2
and H6 of C6H5); 9.78 (s, 1H, NH–CO) ppm. Anal.
C20H24N2O3S (C, H, N); Mr 372.
6.4.1. Synthesis of trans-N-[4-(phenylaminomethyl)cyclo-
hexylmethyl]benzenesulfonamide (53)
From 31 (2.02 mmol, 0.75 g), BH4Na (15.9 mmol, 0.60 g)
and a mix of dioxane (10 ml) and glacial acetic acid (0.6 ml)
to obtain 53 as a white solid (0.50 g, 69%). m.p. 123–125 °C;
IR (KBr): m 1315 and 1152 (s, SO2–N); 1H NMR (DMSO-d6,
400 MHz) d: 0.74–0.94 (m, 4H, Ha of CH–CH2–CH2–CH–
CH2–N); 1.29 (s, 1H, CH–CH2–CH2–CH–CH2–N); 1.43 (s,
1H, CH–CH2–CH2–CH–CH2–N); 1.70 (d, 2H, He of CH–
CH2–CH2–CH–CH2–N, JHe = 11.1 Hz); 1.80 (d, 2H, He of
CH–CH2–CH2–CH–CH2–N, JHe = 11.1 Hz); 2.57 (t, 2H,
SO2–NH–CH2, JCH2–NH = 6.4 Hz); 2.80 (t, 2H, CH–CH2–
CH2–CH–CH2–N, JCH2–NH = 5.7 Hz); 5.53 (t, 1H, NH–
C6H5, JNH–CH2 = 5.7 Hz); 6.45–6.53 (m, 3H, H2, H4 and H6
of NH–C6H5); 7.03 (t, 2H, H3 and H5 of NH–C6H5,
J = 7.8 Hz); 7.57–7.64 (m, 4H, H3, H4 and H5 of C6H5 and
The rest of the amide derivatives were prepared simi-
larly.

A. Moreno et al. / European Journal of Medicinal Chemistry 39 (2004) 49–58
55
SO2–NH); 7.78–7.80 (m, 2H, H2 and H6 of C6H5) ppm.
Anal. C20H26N2O2S (C, H, N); Mr 358.
6.6.1. Synthesis of trans-N-[4-(3-benzyl-1-phenylureido-
methyl)cyclohexylmethyl}benzenesulfonamide (65)
The rest of the amine derivatives were prepared similarly.
From 53 (1.40 mmol, 0.50 g) and benzylisocyanate
(1.54 mmol, 0.20 g) to obtain 65 as a white solid (0.40 g,
58%). m.p. 162–164 °C; IR (KBr): m 1637 (s, urea C=O);
1327 and 1161 (s, SO2–N); 1H NMR (DMSO-d6, 400 MHz)
d: 0.61–0.85 (m, 4H, Ha of CH–CH2–CH2–CH–CH2–N);
1.24 (s, 2H, CH–CH2–CH2–CH–CH2–N); 1.64 (d, 4H, He of
CH–CH2–CH2–CH–CH2–N, JHe = 10.4 Hz); 2.54 (m, 2H,
SO2–NH–CH2, JCH2–NH = 6.3 Hz); 3.45 (d, 2H, CH–CH2–
CH2–CH–CH2–N, JCH2–CH = 7.1 Hz); 4.18 (d, 2H, CH2–
C6H5, JCH2–NH = 5.9 Hz); 6.10 (t, 1H, CO–NH, JNH–
CH2 = 5.9 Hz); 7.19 (d, 3H, H2, H4 and H6 of CH2–C6H5,
J = 7.3 Hz); 7.24–7.31 (m, 5H, H2, H4 and H6 of N–C6H5 and
H3 and H5 of CH2–C6H5); 7.42 (t, 2H, H3 and H5 of
N–C6H5, J = 7.6 Hz); 7.51–7.62 (m, 4H, H3, H4 and H5 of
C6H5 and SO2–NH); 7.78 (d, 2H, H2 and H6 of C6H5,
JH2,6–H3,5 = 6.8 Hz) ppm. Anal. C28H33N3O3S·1/2H2O (C, H,
N); Mr 500.
6.5. General procedure for the synthesis of trans-N-{4-
[(N′formyl-N′R1-ylamino)methyl]cyclohexylmethyl}benzene-
sulfonamide (55–58
)
Ten milliliters of dry POCl3 was added dropwise to a
100 ml round-bottomed flask with 30 ml of dry N,N-DMF,
provided with a magnetic stirring bar and a CaCl2 tube. This
addition was carried out for 30 min at 0 °C. Next, the system
was stirred at room temperature for 20 min and a mixture of
51–54 (1.00 g) in N,N-DMF (5 ml) was added dropwise
during 20 min at 0–10 °C. The reaction was then heated to
40 °C during 2 h. At 0 °C, the mixture was hydrolyzed with
ice. NaOH 10% was added to pH 8 and the mixture was
heated until boiling. The mixture was left overnight at 0 °C
and a precipitate was formed. The precipitate was purified by
flash chromatography (CH2Cl2 to CH2Cl2/MetOH) in order
to obtain compounds 55–58.
The rest of the urea derivatives were prepared similarly.
6.6.2. Synthesis of trans-N-[4-(1-isopropyl-3-phenylthiou-
reidomethyl)cyclohexylmethyl]benzenesulfonamide (63)
Compound 51 (1.54 mmol, 0.50 g) and 30 ml of dry
CH2Cl2 were added to a 100 ml round-bottomed flask
equipped with a magnetic stirring bar and a CaCl2 tube.
Phenylisothiocyanate (3.34 mmol, 0.45 g) was added using a
syringe and the reaction mixture was stirred for 5 h at room
temperature. n-Hexane was added until a white precipitate
was obtained. The precipitate was filtered and washed with
n-hexane (2 × 10 ml) and then recrystallized from
i-PrOH:H2O (3:1) in order to obtain 63 as a white solid
(0.20 g, 28%). m.p. 130–132 °C; IR (KBr): m 1337 and 1155
6.5.1. Synthesis of trans-N-{4-[(N-formyl-N-phenylamino)
methyl]cyclohexylmethyl}benzene sulfonamide (57)
From 53 (2.80 mmol, 1.00 g) and after purification by
flash chromatography (CH2Cl2/MetOH 97/3) in order to ob-
tain 57 as a white solid (0.22 g, 20%). m.p. 83–85 °C. IR
(KBr): m 1653 (s, formyl C=O); 1327 and 1161 (s, SO2–N);
1H NMR (DMSO-d6, 400 MHz) d: 0.60–0.71 (m, 2H, Ha of
CH–CH2–CH2–CH–CH2–N); 0.75–0.91 (m, 2H, Ha of CH–
CH2–CH2–CH–CH2–N); 1.20–1.39 (m, 2H, CH–CH2–
CH2–CH–CH2–N); 1.60 (t, 4H, He of CH–CH2–CH2–CH–
CH2–N, JHe = 11.2 Hz); 2.49–2.53 (m, 2H, SO2–NH–CH2);
3.65 (d, 2H, CH–CH2–CH2–CH–CH2–N, JCH2–CH = 7.2 Hz);
7.23–7.30 (m, 1H, H4 of N–C6H5); 7.34 (d, 2H, H2 and H6 of
N–C6H5, JH2,6–H3,5 = 7.4 Hz); 7.42 (t, 2H, H3 and H5 of
N–C6H5); 7.51–7.65 (m, 4H, H3, H4 and H5 of C6H5 and
SO2–NH); 7.75 (t, 2H, H2 and H6 of C6H5); 8.26 and 8.40
(2s, 1H, CHO) ppm. Anal. C21H26N2O3S·1/2H2O (C, H, N);
Mr 395.
1
(s, SO2–N); H NMR (DMSO-d6, 400 MHz) d: 0.70–0.78
(m, 2H, Ha of CH–CH2–CH2–CH–CH2–N); 0.83–0.94 (m,
2H, Ha of CH–CH2–CH2–CH–CH2–N); 1.13 (d, 6H, CH–
(CH3)2, JCH3–CH = 6.8 Hz); 1.27 (ws, 1H, CH–CH2–CH2–
CH–CH2–N); 1.61–1.80 (m, 5H, He of CH–CH2–CH2–CH–
CH2–N and CH–CH2–CH2–CH–CH2–N); 2.56 (t, 2H, SO2–
NH–CH2, JCH2–NH = 6.3 Hz); 3.31–3.39 (m, 2H, CH–CH2–
CH2–CH–CH2–N); 5.34 (ws, 1H, CH–(CH3)2); 7.10 (t, 1H,
H4 of NH–C6H5); 7.18 (d, 2H, H2 and H6 of NH–C6H5,
JH2,6–H3,5 = 7.8 Hz); 7.29 (t, 2H, H3 and H5 of NH–C6H5,
JH3,5–H2,6 = 7.8 Hz); 7.57–7.63 (m, 4H, H3, H4 and H5 of
C6H5 and SO2–NH); 7.72 (d, 2H, H2 and H6 of C6H5,
JH6–H3,5 = 6.6 Hz); 8.89 (s, 1H, NH–CS) ppm. Anal.
C24H33N3O2S2·1/2H2O (C, H, N); Mr 468.
The rest of the N-formyl derivatives were prepared simi-
larly.
6.6. General procedure for the synthesis of trans-N-[4-
(3-R2-yl-1-R1-ylureidomethyl)cyclohexylmethyl}benzene-
sulfonamide
Compounds 51–53 (0.50 g, 1 equiv.) and 30 ml of dry
CH2Cl2 were added to a 100 ml round-bottomed flask
equipped with a magnetic stirring bar and a CaCl2 tube. The
corresponding isocyanate 59 (1.10 equiv.) was added using a
syringe and the reaction mixture was stirred for 5 h at room
temperature. n-Hexane was added until a white precipitate
was obtained. The precipitate was filtered and washed with
n-hexane (2 × 10 ml) and then recrystallized from
i-PrOH:H2O (3:1) in order to obtain urea derivatives (60–62,
64–66).
Acknowledgements
This group of authors wishes to thank Carmen Elizalde
and Lara Orús for their collaboration. We wish to thank the
Asociación de Amigos de la Universidad de Navarra for
grants given to A. Moreno.

56
A. Moreno et al. / European Journal of Medicinal Chemistry 39 (2004) 49–58
Elemental microanalysis
Compound
Calculated
Found
Compound
Calculated
Found
(I) IC50 (NPYY5) results of the amide derivatives
6a
C: 56.56
H: 6.40
N: 4.71
C: 44.69
H: 4.82
N: 3.72
C: 60.18
H: 7.37
N: 4.13
C: 60.67
H: 6.17
N: 3.93
C: 58.62
H: 5.75
N: 8.05
C: 62.25
H: 6.04
N: 4.03
C: 51.87
H: 5.86
N: 4.32
C: 60.36
H: 7.69
N: 8.28
C: 56.47
H: 7.05
N: 8.24
C: 63.49
H: 7.94
N: 7.41
C: 57.60
H: 6.93
N: 7.47
C: 59.26
H: 6.17
N: 11.52
C: 62.50
H: 7.08
N: 8.75
C: 61.86
H: 7.22
N: 14.43
C: 50.58
H: 5.36
N: 13.41
C: 54.10
H: 5.73
N: 17.21
C: 62.07
H: 6.36
N: 13.93
C: 56.60
H: 6.34
N: 4.57
C: 44.51
H: 4.83
N: 3.58
C: 59.92
H: 7.70
N: 4.52
C: 60.59
H: 5.84
N: 3.79
C: 58.50
H: 5.82
N: 7.95
C: 62.48
H: 6.27
N: 4.02
C: 52.04
H: 5.72
N: 4.24
C: 59.97
H: 7.80
N: 8.10
C: 56.07
H: 6.90
N: 8.27
C: 63.45
H: 7.98
N: 7.25
C: 57.91
H: 7.37
N: 7.41
C: 59.01
H: 6.12
N: 11.47
C: 62.22
H: 7.02
N: 9.14
C: 61.87
H: 7.38
N: 14.44
C: 50.28
H: 5.47
N: 13.01
C: 53.93
H: 5.62
N: 17.17
C: 62.35
H: 6.32
N: 13.86
6b
C: 44.69
H: 4.82
N: 3.72
C: 49.12
H: 5.26
N: 8.19
C: 48.00
H: 5.60
N: 3.73
C: 57.14
H: 5.60
N: 7.84
C: 50.69
H: 5.43
N: 4.22
C: 50.69
H: 5.43
N: 4.22
C: 48.00
H: 4.86
N: 4.00
C: 61.36
H: 7.95
N: 7.95
C: 57.63
H: 7.34
N: 7.91
C: 62.64
H: 7.69
N: 7.69
C: 60.00
H: 7.37
N: 7.37
C: 60.58
H: 6.31
N: 8.83
C: 59.59
H: 6.54
N: 15.80
C: 54.01
H: 5.48
N: 13.70
C: 52.97
H: 5.95
N: 13.44
C: 55.29
H: 5.86
N: 14.65
C: 59.64
H: 5.96
N: 16.70
C: 44.71
H: 4.84
N: 3.66
C: 49.01
H: 5.22
N: 7.96
C: 47.78
H: 5.92
N: 3.64
C: 57.29
H: 5.99
N: 7.85
C: 50.71
H: 5.43
N: 4.20
C: 50.63
H: 5.65
N: 4.24
C: 48.31
H: 4.86
N: 4.10
C: 61.06
H: 7.95
N: 7.85
C: 57.59
H: 7.39
N: 7.60
C: 62.33
H: 7.43
N: 7.48
C: 59.84
H: 7.20
N: 7.51
C: 60.50
H: 6.56
N: 8.68
C: 59.49
H: 6.66
N: 15.62
C: 53.62
H: 5.48
N: 13.50
C: 52.57
H: 6.21
N: 13.29
C: 54.90
H: 5.89
N: 14.77
C: 59.32
H: 6.22
N: 16.41
6c
6d
6e
6f
6g·1/2H2O
6h
6i
6j
6k
6l
6m·1/2H2O
6n
8
9
10
11
12
13
14·1/2H2O
15
16
17
18·1/2H2O
19
20
21
22
23
24
25
26·1/2H2O
27·1/2H2O
(continued on next page)

A. Moreno et al. / European Journal of Medicinal Chemistry 39 (2004) 49–58
57
Elemental microanalysis (continued)
Compound
Calculated
C: 62.37
H: 6.44
N: 14.55
C: 58.45
H: 5.84
N: 9.74
C: 52.13
H: 5.00
N: 6.08
C: 59.04
H: 5.65
N: 6.88
C: 63.88
H: 5.79
N: 9.72
C: 60.33
H: 5.25
N: 9.18
C: 62.58
H: 5.44
N: 9.52
C: 56.11
H: 4.68
N: 8.54
C: 47.11
H: 4.62
N: 12.93
C: 58.74
H: 5.36
N: 9.79
C: 64.93
H: 6.01
N: 11.22
C: 56.91
H: 5.57
N: 14.43
Found
Compound
Calculated
C: 67.41
H: 6.51
N: 6.29
C: 64.52
H: 6.45
N: 7.53
C: 68.25
H: 6.16
N: 6.64
C: 61.13
H: 6.17
N: 11.26
C: 62.25
H: 5.91
N: 9.93
C: 54.99
H: 4.78
N: 8.37
C: 54.99
H: 4.78
N: 8.37
C: 59.85
H: 5.70
N: 13.30
C: 57.53
H: 5.25
N: 9.59
C: 57.53
H: 5.25
N: 9.59
C: 66.12
H: 6.12
N: 1.43
Found
28
C: 61.99
H: 6.84
N: 14.25
C: 58.77
H: 5.93
N: 9.74
C: 52.26
H: 5.00
N: 6.29
C: 58.48
H: 5.88
N: 7.10
C: 63.78
H: 6.20
N: 9.75
C: 60.24
H: 5.37
N: 9.23
C: 62.21
H: 5.55
N: 9.31
C: 55.79
H: 4.79
N: 8.41
C: 47.22
H: 5.01
N: 12.69
C: 58.61
H: 5.61
N: 9.43
C: 64.90
H: 6.22
N: 11.43
C: 56.54
H: 5.48
N: 14.09
29·1/2H2O
C: 67.01
H: 6.32
N: 6.01
C: 64.16
H: 6.42
N: 7.56
C: 68.01
H: 6.12
N: 6.25
C: 60.78
H: 6.36
N: 11.34
C: 64.94
H: 6.09
N: 9.61
C: 55.04
H: 5.00
N: 8.26
C: 54.67
H: 5.09
N: 8.05
C: 60.15
H: 5.54
N: 13.24
C: 57.37
H: 5.30
N: 9.90
C: 57.80
H: 5.51
N: 9.72
C: 65.84
H: 6.02
N: 11.37
30
31
32
33
34
35
36·1/2H2O
37
38
39
40
41
42
43·1/2H2O
45·1/2H2O
47·1/2H2O
49
44·1/2H2O
46
48·1/2H2O
50
(II) IC50 (NPYY5) results of the amine derivatives
51
C: 62.96
H: 8.64
N: 8.64
C: 67.04
H: 7.26
N: 7.82
C: 62.83
H: 8.74
N: 8.28
C: 66.91
H: 7.16
N: 7.68
52
54
C: 65.93
H: 8.79
N: 7.69
C: 70.59
H: 6.89
N: 6.86
C: 65.90
H: 8.70
N: 7.58
C: 70.19
H: 6.81
N: 6.52
53
(III) IC50 (NPYY5) results of the N-formyl derivatives
55
C: 61.36
H: 7.95
N: 7.95
C: 63.80
H: 6.83
N: 7.09
C: 61.62
H: 8.07
N: 7.69
C: 63.95
H: 6.96
N: 6.77
56
C: 64.28
H: 8.16
N: 7.14
C: 67.41
H: 6.52
N: 6.29
C: 64.04
H: 8.30
N: 7.17
C: 67.41
H: 6.52
N: 6.26
57·1/2H2O
58·1/2H2O
(continued on next page)

58
A. Moreno et al. / European Journal of Medicinal Chemistry 39 (2004) 49–58
Elemental microanalysis (continued)
Compound
Calculated
Found
Compound
Calculated
Found
(IV) IC50 (NPYY5) results of the (thio)urea derivatives
60
62
64
66
C: 65.64
H: 7.66
N: 9.19
C: 67.29
H: 6.92
N: 7.85
C: 67.60
H: 7.85
N: 8.45
C: 69.60
H: 6.15
N: 7.38
C: 65.38
H: 8.01
N: 8.80
C: 66.94
H: 6.83
N: 7.91
C: 67.50
H: 7.72
N: 8.31
C: 69.02
H: 6.08
N: 7.15
61
C: 65.01
H: 7.45
N: 9.48
C: 61.54
H: 7.56
N: 8.97
C: 68.43
H: 6.72
N: 8.55
C: 64.91
H: 7.45
N: 9.36
C: 61.62
H: 7.40
N: 9.15
C: 68.30
H: 6.61
N: 8.51
63·1/2H2O
65
[10] A. Inui, Trends Pharmacol. Sci. 20 (1999) 43–46.
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