Discovery of 1-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl) -2-imidazolidinone (GSK163090), a potent, selective, and orally active 5-HT 1A/B/D receptor antagonist

Article abstract of DOI:10.1021/jm100714c

In an effort to identify selective drug like pan-antagonists of the 5-HT₁ autoreceptors, studies were conducted to elaborate a previously reported dual acting 5-HT₁ antagonist/SSRI structure. A novel series of compounds was identifie

Full text of DOI:10.1021/jm100714c

8228 J. Med. Chem. 2010, 53, 8228–8240
DOI: 10.1021/jm100714c
Discovery of 1-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-2-imidazolidinone
(GSK163090), a Potent, Selective, and Orally Active 5-HT1A/B/D Receptor Antagonist
Colin P. Leslie,*,† Matteo Biagetti,† Silvia Bison,† Steven M. Bromidge,‡ Romano Di Fabio,† Daniele Donati,†,§
Alessandro Falchi,†, Martine J. Garnier,† Albert Jaxa-Chamiec,†,^ Gary Manchee,†,# Giancarlo Merlo,†
Domenica A. Pizzi,† Luigi P. Stasi,†,3 Jessica Tibasco,† Antonio Vong,‡ Simon E. Ward,‡ and Laura Zonzini†
†Neurosciences Centre of Excellence for Drug Discovery, GlaxoSmithKline SpA, Medicines Research Centre, Via A. Fleming 4, 37135 Verona,
Italy, and ‡Neurosciences Centre of Excellence for Drug Discovery, GlaxoSmithKline, New Frontiers Science Park, Third Avenue, Harlow, Essex
CM19 5AW, United Kingdom. § Present address: Nerviano Medical Sciences Srl, Via Pasteur 10, 20014 Nerviano, Milan, Italy. Present address:
Chiesi Farmaceutici, Via Palermo 26/A, 43122 Parma, Italy. ^ Present address: Imperial College, London, SW7 2AZ, United Kingdom. # Present
address: Pharmidex, 72 New Bond Street, Mayfair, London W1S 1RR, United Kingdom. 3 Present address: Rottapharm, Via Valosa di Sopra 9,
20052 Monza, Italy.
Received June 15, 2010
In an effort to identify selective drug like pan-antagonists of the 5-HT1 autoreceptors, studies were conducted
to elaborate a previously reported dual acting 5-HT1 antagonist/SSRI structure. A novel series of compounds
was identified showing low intrinsic activities and potent affinities across the 5-HT1A, 5-HT1B, and 5-HT1D
receptors as well as high selectivity against the serotonin transporter. From among these compounds,
1-(3-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-2-imidazolidinone (36) was found to com-
bine potent in vivo activity with a strong preclinical developability profile, and on this basis it was selected as
a drug candidate with the aim of assessing its potential as a fast-onset antidepressant/anxiolytic.
Introduction
antidepressant activity of SSRIs both in preclinical3 and
clinical4 settings and, accordingly, several researchers have
endeavored to identify dual acting 5-HT1A antagonists/SSRIs
that hold the promise of faster onset of therapeutic efficacy in
the treatment of depression.5
Much preclinical and clinical evidence highlights the involve-
ment of the serotonergic system in the regulation of mood.1 Of
particular clinical importance are the selective serotonin reup-
take inhibitors (SSRIsa), which represent the first choice for the
treatment of depression. The SSRIs are believed to owe their
efficacy to increased serotonergic neurotransmission brought
about through the elevation of synaptic 5-hydroxytyptamine
(5-HT) levels. Despite their popularity, the SSRIs are associated
with a number of undesirable characteristics including the
latency to therapeutic onset, which typically requires several
weeks of SSRI treatment. It has been hypothesized that this
delay in therapeutic onset is attributable to the time required
for the desensitization of the 5-HT1A receptors, allowing
increased 5-HT levels to be maintained.2 In support of this
hypothesis, coadministration of a 5-HT1A antagonist with an
SSRI has been reported to accelerate the onset of anxiolytic/
5-HT1 autoreceptors are located on both the cell bodies
(5-HT1A, 5-HT1B, and 5-HT1D receptor subtypes) and nerve
terminals (5-HT1B and 5-HT1D receptor subtypes) of 5-HT
neurons.6 They are widely distributed in the brain, and it has
been documented that the 5-HT1A, 5-HT1B, and 5-HT1D
receptors play an important role in regulating the release of
5-HT on the 5-HT cell bodies7 and on the nerve terminals.8
Thus the concurrent blockade of all three autoreceptors,
5-HT1A, 5-HT1B, and 5-HT1D, should lead to an elevation of
extracellular 5-HT concentrations. Indeed, microdialysis
studies in guinea pig have confirmed that the combination
of 5-HT1A and 5-HT1B antagonism results in an acute syner-
gistic enhancement of 5-HT levels,9 comparable to that ob-
served following a period of chronic SSRI treatment. It
*To whom correspondence should be addressed. Phone: þ39 045
8218546. Fax: þ39 045 8218196. E-mail: colin.leslie@aptuit.com.
a Abbreviations: SSRI, selective serotonin reuptake inhibitor; 5-HT,
5-hydroxytyptamine; SerT, serotonin transporter; SAR, structure
-activity relationship; GTPγS, guanosine 50-O-[γ-thio]triphosphate;
DMPK, drug metabolism and pharmacokinetics; CYP450, cytochrome
P450; hERG, human ether-a-go-go-related-gene; CNS, central nervous
system; PD, pharmacodynamic; 8-OH-DPAT, 8-hydroxy-N,N-dipro-
pyl-2-aminotetralin; hLMA, hyperlocomotor activity; DDI, drug-drug
interactions; P-gp, P-glycoprotein; MDCK, Madin-Darby canine kid-
ney; hMDR1, human multidrug resistance 1 protein; BA, basolateral-
to-apical; AB, apical-to-basolateral; IA, intrinsic activity; ND, value not
determined; inv, inverse agonist; NMR, nuclear magnetic resonance;
LCMS, liquid chromatography/mass sprectroscopy; Clint, intrinsic
clearance; compd, compound; clogP, calculated octanol/water parti-
tion coefficient; Clb, blood clearance; t1/2, half-life; Fpo, oral bioavail-
ability; Cmax, maximum concentration.
follows, therefore, that a pan-antagonist of the 5-HT1A
,
5-HT1B, and 5-HT1D receptors may be postulated to exhibit
a similar therapeutic profile to a dual acting 5-HT1A antagonist/
SSRI through an acute and sustained increase of postsynaptic
5-HT neurotransmission. Consequently, a pan-antagonist of
the 5-HT1 autoreceptors may constitute a novel approach for
the treatment of depression/anxiety with potential advantages
in the latency to therapeutic onset.
This approach has been targeted within our laboratories, as
well as by others,10 and a series of recent publications have
documented our progress.11,12 A tactic that has proven suc-
cessful in furnishing selective 5-HT1 antagonist tools, such as
1, is the modification of the benzoxazinone portion of the dual
r
pubs.acs.org/jmc
Published on Web 11/05/2010
2010 American Chemical Society

Article
Journal of Medicinal Chemistry, 2010, Vol. 53, No. 23 8229
acting 5-HT1 antagonist/SSRI lead 2 (Figure 1) identified
within our laboratories.13 Exclusion of the benzoxazinone
substructure, which is a key pharmacophoric requirement for
potent inhibition of the serotonin transporter (SerT), readily
removed SerT activity while judicious replacement with alter-
native groups allowed potent 5-HT1 binding to be restored.12
Recently, our laboratories have described a newer benzoxazi-
none dual acting 5-HT1 antagonist/SSRI lead 3 (Figure 1),14
endowed with increased 5-HT1 antagonist activity and a
superior pharmacokinetic profile. Here, we report our studies
applying an analogous tactic, modifying the benzoxazinone
moiety of 3, that led to the discovery of a new potent and se-
lective series of 5-HT1 antagonists from which a preclinical
candidate was selected.
Results and Discussion
From the outset, the medicinal chemistry strategy was en-
tirely focused on replacement of the benzoxazinone portion of
molecule 3. Experience gained working with related series of
5-HT1A/B/D antagonists and dual acting 5-HT1A antagonists/
SSRIs has taught that the 2-methylquinoline is fundamental
for combining high 5-HT1A/B/D affinities with low intrinsic
activities;15 assuch, the 2-methylquinoline group isconsidered
optimal and hence this portion of the molecule was not
targeted for modification. Likewise, modifications to the
ethylpiperazine linker were not envisaged because our starting
point, compound 3, was itself the product of an extensive
exploration of the linker group14 and the ethylpiperazine
linker was considered optimized.
On the basis of the findings from the SAR exploration around
lead 2 that had led to the identification of compound 1,12 we
began by targeting the replacement of the benzoxazinone group
in compound 3 with a 3-substituted phenyl group, in particular
the methyl sulfonamide derivative. The target compounds were
prepared following the synthetic sequence outlined in Scheme 1
that was designed to allow rapid parallel SAR expansion.
A slightly modified route to prepare 2-methyl-5-(1-piper-
azinyl)quinoline 7 than previously published was employed. A
palladium catalyzed Buchwald-Hartwig coupling remains
a key step in the synthetic sequence, but passing via the triflate
ester of the quinoline group rather than the corresponding bro-
mide afforded greatly improved yields and simplified purifica-
tion procedures. Subsequent alkylation with (3-nitrophenyl)
ethyl methanesulfonate and reduction of the nitro group with
Figure 1. Structures of 1, a 5-HT1 receptor antagonist, and 2 and 3,
dual acting 5-HT1 receptor antagonist/serotonin reuptake inhibitors.
Scheme 1a
a Reagents and conditions: (i) Tf2O, pyridine, dichloromethane, 0 ꢀC, 92%; (ii) 1-Boc-piperazine, Cs2CO4, Pd(OAc)2, BINAP, toluene, reflux, 62%;
(iii) TFA, dichloromethane, room temp, 96%; (iv) 2-(3-nitrophenyl)ethyl methanesulfonate, DIPEA, DMF, 100 ꢀC, 64%; (v) Fe powder, NH4Cl,
MeOH, reflux, 84%; (vi) for sulfonamides RSO2Cl, pyridine, room temp, 44-62%; for amides RCO2H, EDC, HOBt, dichloromethane/DMF, room
temp or RCOCl, DIPEA, dichloromethane, room temp; for ureas RNCO, dichloromethane, room temp or triphosgene, TEA, RNH2, 0 ꢀC; for
carbamates (RO)COCl, DIPEA, dichloromethane, 0 ꢀC; (vii) MeI, NaH, THF, 0 ꢀC; (viii) NaH, THF, 0 ꢀC.

8230 Journal of Medicinal Chemistry, 2010, Vol. 53, No. 23
Leslie et al.
Table 1. Receptor Binding Affinity (pKia) and Intrinsic Activities for 5-HT1A, 5-HT1B, and 5-HT1D Receptors and Functional Inhibition of SerT for
Novel Compounds
pKi
compdb
R2
R3
5-HT1A (IA)
5-HT1B (IA)
5-HT1D (IA)
SerT
1
8.6 (inv)
9.6 (0.2)
7.8 (ND)
9.1 (0.0)
8.8 (ND)
9.0 (0.0)
8.7 (0.0)
8.7 (inv)
8.2 (inv)
9.0 (inv)
9.0 (inv)
9.2 (inv)
8.9 (inv)
8.6 (ND)
8.7 (ND)
8.5 (inv)
9.3 (ND)
9.1 (inv)
9.4 (inv)
8.7 (0.0)
8.3 (ND)
8.1 (ND)
8.4 (0.0)
8.5 (ND)
8.4 (0.0)
8.6 (ND)
9.4 (0.0)
8.9 (ND)
8.7 (0.1)
9.4 (0.0)
8.5 (ND)
9.4 (0.0)
8.6 (ND)
8.5 (ND)
9.3 (ND)
8.7 (0.3)
9.3 (0.1)
8.1 (ND)
9.1 (0.1)
8.7 (ND)
9.3 (0.0)
8.9 (inv)
8.8 (inv)
8.7 (inv)
8.6 (inv)
8.5 (0.0)
8.5 (inv)
8.3 (inv)
8.4 (ND)
8.8 (ND)
8.4 (inv)
8.9 (ND)
8.5 (inv)
8.7 (0.0)
8.9 (inv)
8.7 (ND)
8.4 (ND)
8.5 (0.0)
9 (ND)
9.3 (0.0)
9.8 (inv)
9.3 (ND)
9.9 (inv)
9.2 (ND)
9.6 (inv)
9.7 (inv)
9.8 (inv)
9.5 (inv)
9.5 (inv)
9.6 (inv)
9.5 (inv)
9.4 (0.0)
9.2 (ND)
9.8 (ND)
9.3 (inv)
9.7 (ND)
9.4 (inv)
9.6 (inv)
9.8 (inv)
9.8 (ND)
9.6 (ND)
9.5 (0.0)
9.7 (ND)
9.2 (0.0)
9.3 (ND)
9.6 (0.0)
9.9 (ND)
9.5 (0.0)
9.7 (0.0)
9.5 (ND)
9.8 (inv)
9.6 (ND)
8.8 (ND)
9.8 (ND)
6
7.6
ND
5.5
ND
5.9
5.9
5.9
5.8
5.7
6.2
6.2
6.1
6.1
5.9
5.9
6.4
6.3
6.3
6.3
6.1
6.1
5.7
5.7
5.6
5.9
6.3
6.1
ND
6.1
ND
6.3
ND
4.7
6.5
3
9
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
Me
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
-SO2Me
-SO2Pr
-COMe
-COEt
-COiPr
-COtBu
-COPh
-CO-2-F-Ph
-CO-3-F-Ph
-CO-4-F-Ph
-CO-2-OMe-Ph
-CO-3-OMe-Ph
-CO-4-OMe-Ph
-CO-pyrazin-2-yl
-CO-2-Me-thiazol-4-yl
-CO-4-Me-thiazol-5-yl
-CONHEt
-CONHPr
-CONHtBu
-CONHPh
-CONH-2-F-Ph
-CONH-3-F-Ph
-CONH-4-F-Ph
-CO2Me
-CO2Et
-COMe
-CONHCH2CH2-
-CONHCH2 CH2CH2-
-CO2CH2CH2-
-CO2CH2CH2CH2-
-COCH2CH2CO-
-NCHCHCH-
8.4 (inv)
8.5 (ND)
9.3 (inv)
8.9 (ND)
7.9 (0.2)
8.5 (0.0)
7.4 (ND)
8.7 (0.0)
7.5 (ND)
7.4 (ND)
8.8 (ND)
a Radioligand binding assay to determine affinity at human recombinant 5-HT receptors and functional [3H]-5-HT uptake assays in rat cortical
synaptosomes to determine potency for SerT. Each determination lies within 0.3 log units of the mean with a minimum of three replicates. Values in
parentheses are intrinsic activity (IA) values relative to the maximum response elicited by the endogenous agonist 5-HT. inv = inverse agonist behavior
was observed. ND = value not determined. b All compounds were characterized and purity was assessed using 1H NMR and LCMS.
iron powder/ammonium chloride in methanol afforded the
versatile intermediate 9, ready for functionalization.
from the functional assays. Intrinsic activities are reported
relative to the maximum response elicited by the endogenous
agonist 5-HT (IA = 1.0); in some cases, test compounds were
found to lower [35S]-GTPγS binding below basal levels and
these are indicated as inverse agonists (IA = inv). The desired
profile for compound progression was set at pKi > 8.0 for all
three targets and either silent antagonism (IA = 0.0) or
inverse agonism at each receptor.
The in vitro target activities of the compounds described
in this manuscript were assessed using a two-tier screening
cascade. First, the 5-HT1A, 5-HT1B, and 5-HT1D affinities of
all compounds prepared were evaluated in radioligand bind-
ing assays in stably transfected recombinant cell lines. Subse-
quently, the functional activities of selected compounds were
assessed in [35S]-GTPγS binding assays, again in cells stably
transfected with the relevant receptor. Data are reported as
pKi values from the binding assays and intrinsic activities (IA)
In confirmation of our working hypothesis, the initially
prepared methyl sulfonamide derivative 10 was found to
maintain subnanomolar affinity for the 5-HT1A, 5-HT1B, and

Article
Journal of Medicinal Chemistry, 2010, Vol. 53, No. 23 8231
Table 2. Intrinsic Clearance (Clint) in Rat, Human, and Dog Liver Microsomes and in Vitro Cross-Screening (pKi) in Radioligand Binding Assaysa
pKi 5-HT
pKi dopamine
D2 D3
6.4 6.7
compdb
Clint (mL/min/g) rat/hum/dog
pKi hERG
clogPc
2A
6.1
2B
6.4
2C
6
7
10
12
16
23
24
26
29
33
36
38
41
1.4/<0.5/14.4
<0.5/<0.5/7.7
1.7/2.8/46.0
0.7/4.9/16.0
1.8/3.1/9.9
6.3
5.4
3.7
4.1
5.4
4.3
5.4
4.5
5.8
4.5
3.5
3.9
5.0
5.5
6.0
<5.6
<5.4
<6.0
6.1
7.0
6.6
7.1
6.8
6.8
6.9
6.1
7.2
7.1
6.7
6.4
6.4
6.7
6.8
7.0
7.1
7.3
6.1
ND
6.5
6.2
<5.8
ND
6.1
ND
ND
ND
<5.2
6.5
ND
ND
ND
0.7/1.3/1.3
6.5
<5.2
6.7
6.4
<5.2
6.7
7.4
7.1
7.6
6.8
6.3
6.9
6.5
7.1
6.7
6.3
6.1
6.4
6.9
7.5
7.0
6.7
6.7
7.3
2.0/1.8/18.2
2.3/<0.5/-
0.7/1.2/5.0
6.5
<5.0
6.1
5.8
ND
4.9
5.7
<5.8
<5.3
5.5
6.0
6.1
6.3
5.9
<0.5/1.2/3.8
<0.5/3.5/-
<5.3
5.7
ND
6.4
7.1
<5.0
a Radioligand binding assay to determine affinity at human recombinant 5-HT, dopamine receptors and hERG channel. Each determination lies
within 0.3 log units of the mean with a minimum of two replicates. ND = value not determined. b All compounds were characterized and purity was
assessed using 1H NMR and LCMS. c Calculated octanol/water partition coefficient using Daylight 4.81 software.16
5-HT1D receptors while the SerT activity was reduced by more
than 100-fold compared to the parent benzoxazinone struc-
ture 3 (Table 1). Furthermore, the intrinsic activities observed
for 10 were even lower than those of 3, eliminating any risk of
inducing partial agonism in an in vivo setting;
compounds, with essentially all compounds exhibiting good
metabolic stability and low CYP450 inhibition (data not
shown). However, monitoring metabolic stability in the higher
species and screening for off-target selectivity against mono-
amine targets allowed differentiation of the best molecules for
progression into in vivo studies. Data for some representative
examples are shown in Table 2. As can be appreciated, selectivity
against other 5-HT receptor subtypes and dopamine receptors
was generally high, although some specific substitution patterns
had modest 5-HT7 or D3 affinities such that selectivity dropped
below 50-fold. On the other hand, affinity toward the human
ether-a-go-go-related-gene (hERG) potassium channel and high
intrinsic clearance in dog liver microsomes represented an issue
for a number of substrates.
Although low metabolic stability in the dog posed a prob-
lem, in that it could potentially preclude the possibility of
reaching adequate systemic exposure in toxicological studies,
the affinity of compounds toward the hERG channel was a
much greater concern. Inhibition of the hERG channel is
associated with prolongation of the cardiac QT interval, an
effect which is in turn linked to life-threatening ventricular
arrhythmias (Torsades de Pointes) in the clinic.17 With the
exception of a few outliers, such as the sulphonamide 10 which
presumably has a specific interaction with the channel, the
affinity for hERG grew steadily with increasing lipophilicity
of the substrate. The substrates with lower hERG affinities,
and hence lower lipophilicities, also tended to be those with
lower intrinsic clearances, making them the obvious choice for
progression into in vivo pharmacokinetic studies.18
In accord with the low intrinsic clearance values measured
in vitro and their favorable physicochemical properties, the
selection of compounds further profiled in rat pharmacoki-
netic studies showed low blood clearance, high oral bioavail-
ability, and moderate half-lives (Table 3). Additionally, all
substrates showed appreciable partitioning into the central
nervous system (CNS), confirming their suitability as cen-
trally acting 5-HT1 antagonists.
To establish that the compounds were functionally exerting
their pharmacological activity in vivo, they were investigated
in a 5-HT1A pharmacodynamic (PD) model in rats. In this
model, compounds are evaluated for their ability to reverse
the hyperlocomotion induced by administration of the selec-
tive 5-HT1A agonist 8-OH-DPAT (0.2 mg/kg sc). Compounds
10, 12, and 36 all demonstrated clear dose-dependent inhibi-
tion of the 8-OH-DPAT-induced hyperlocomotor activity
(hLMA), with ED50 values ranging from 0.03 to 1 mg/kg
Having verified that such a strategy was valid, we embarked
ona broader exploration of the substituent atthe 3-position of
the phenyl ring. Aniline 9 reacted smoothly with a variety of
electrophiles to generate a series of sulfonamide, amide, urea,
and carbamate derivatives. Cyclic urea and carbamate deri-
vatives were accessed by reaction with halogenated isocya-
nates or chloroformates and subsequent cyclization with
sodium hydride. Gratifyingly, the majority of the analogues
demonstrated high binding affinities (pKi>8) against all three
target receptors, including the 5-HT1B receptor, which had
proven the most elusive in previous pan 5-HT1 antagonist
series.12 Moreover, SerT activities were uniformly low such
that these analogues all exhibited >100-fold selectivity over
SerT as desired. In contrast to our previous experience,12 the
nature of the 3-substituent in this series was found to have
little or no influence on the intrinsic activities, with all com-
pounds exhibiting silent antagonism (IA = 0.0) or inverse
agonism in GTPγS functional assays. Data for a selection of
the compounds prepared is shown in Table 1.
It is noteworthy that such a large variety of functionalities
are well tolerated, suggesting that the substituent at the
3-position does not represent a key pharmacophoric point,
yet the intermediate 9 has modest affinities for 5-HT1A and
5-HT1B and N-methylation of the acetamide derivative leads
to an appreciable drop in 5-HT1B affinity (35 vs 12), indicating
that both hydrogen bond acceptor and hydrogen bond donor
interactions may be contributing to the high affinities ob-
served. Although there does not appear to be any particular
restriction to the size of the substituent that is tolerated in this
position, there is a tendency for the smallest substituents to
have the highest affinities, especially at the 5-HT1A receptor.
The marked preference for the 5- vs 6-membered cyclic urea/
carbamate derivatives (36 vs 37 and 38 vs 39) is believed to be
more a consequence of the spatial orientation of the hydrogen
bond acceptor than a result of steric incompatibility.
With a large number of compounds satisfying progression
criteria inour primary assays, the secondary screening cascade
became the principal filter for triaging compounds. Typical in
vitro DMPK screening consisting of determining metabolic
stability toward rat/human liver microsomes and CYP450
inhibition also proved inefficient in prioritizing between

8232 Journal of Medicinal Chemistry, 2010, Vol. 53, No. 23
Leslie et al.
Table 3. Solubility,a Pharmacokinetic Properties in Ratb and in Vivo Activity in 5-HT1A-Agonist Driven Pharmacodynamic (PD) Model in Ratc
solubility at
pH1.2/pH5.5 (mg/mL)
Cmax
(ng/mL)
AUC0-inf
(ng h/mL)
hLMA ED50
(mg/kg)
compdd
Clb (mL/min/kg)
t1/2 (h)
Fpo
%
CNS Br/Bl
3
1446
10
12
36
>10/0.6
>10/5.0
>10/0.5
7
10
11
3.9
4.6
3.2
56
243
98
0.5
0.7
0.5
1.0
51
58
893
889
0.09
0.03
122
a All compounds demonstrated pH dependent solubility profiles. Solubilities are shown for pH 1.2 (simulated gastric fluid, SGF) and pH 5.5 (fed state
simulated intestinal fluid, FeSSIF) at 25 ꢀC. The solubilities of the dihydrochloride salts of 10, 12, and 36 in water were >10 mg/mL. b In vivo data were
determined with dihydrochloride salts by 0.5 mg/kg iv study in rat; brain/blood ratio was measured after 1 h. Oral bioavailability (Fpo) and area under the
curve extrapolated to infinity (AUC0-inf) were determined by an additional 1 mg/kg po rat PK study. c In vivo antagonist activity was determined by
monitoring the inhibition of the hyperlocomotor activity (hLMA) elicited by sc administration of the 5-HT1A agonist 8-OH-DPAT (0.2 mg/kg). d All
compounds were characterized and purity was assessed using 1H NMR and LCMS.
Table 4. Pharmacokinetic Properties of Compound 36 in Dog and
Cynomolgous Monkeya
concentration of 1 μg/mL showing values of 95.9, 95.5 and
95.9% bound, respectively.
Pharmacokinetic studies in higher preclinical species re-
vealed very high blood clearance in dog (>100% of liver
blood flow) and consequently low oral bioavailability in this
species (Table 4). It is likely that other elimination routes,
besides hepatic extraction, are operating in this species. In
spite of this, a supraproportional increase in systemic expo-
sure was observed upon increasing the oral dose from 1 to 10
mg/kg, suggesting saturation of the hepatic first-pass metab-
olism, such that adequate exposures were achieved to be able
to consider the dog as a possible toxicological test species.
However, higher systemic exposures and a lower, albeit mod-
erate, blood clearance (57% of liver blood flow) were seen in
cynomolgus monkey (Table 4), and this species was elected as
the second preclinical species for safety assessment studies.
When doses of compound 36 were escalated, some behav-
ioral observations were noted in rat and cynomolgus monkey.
Starting from 3 mg/kg in rat and 10 mg/kg in cynomolgus
monkey, some of the animals treated with compound 36 were
observed to have half-closed eyes and subdued behavior.
These effects were temporary and reversible but increased in
incidence and severity with increasing dose. It is not believed
that these side effects are related to the 5-HT1A/1B/1D activity
of 36, but rather they are assumed to be the consequence of
unspecified off-target activities. Although these behavioral
side effects werenot linkedto any toxicological outcomein the
animals, they may prudentially be considered a potentially
limiting factor. As the systemic exposures associated with
these effects (524ng/mL in rat and 1390 ng/mL in cynomolgus
monkey) were much higher than those required for efficacy in
animal models of anxiety (ranging from 2 to 30 ng/mL in
various rat and primate models), there was an ample ther-
apeutic index to endorse the selection of compound 36 as a
preclinical development candidate.
Cmax AUC0-inf
(ng/mL) (ng h/mL)
species
dog
Clb (mL/min/kg) t1/2 (h) Fpo %
3
60
25
0.8
5.3
6
63
1305
1390
2550
4224
cynomolgus
monkey
a In vivo data were determined with the dihydrochloride salt by
0.5 mg/kg iv study in dog and 1.0 mg/kg iv study in cynomolgus monkey.
Oral bioavailability (Fpo) in dog was determined by an additional 1 mg/kg
po dog PK study. Oral bioavailability (Fpo) in cynomolgus monkey as well
as maximum blood exposure (Cmax) and area under the curve extrapolated
to infinity (AUC0-inf) were determined by additional 10 mg/kg po dog and
cynomolgus monkey PK studies.
(Table 3). In particular, attention was drawn to the exception-
ally high in vivo potency observed for compound 36, which
was further complemented by the fact that 36 has the lowest
hERG activity seen within the series, ensuring an ample safety
margin toward cardiac QT effects.
Consequently, more in-depth profiling of compound 36
was conducted to ascertain its suitability for progression as a
potential drug candidate.
A low potential for causing drug-drug interactions (DDI)
was confirmed with low CYP450 inhibition being observed in
the five major human isoforms expressed recombinantly (IC50s
for Gentest Supersomes, 1A2=96 μM, 2C9=60 μM, 2C19=
76 μM, 2D6=86 μM, 3A4=67 μM) as well as in human liver
microsomes (3A4=21-30 μM with midazolam, atorvastatin,
and nifedipine as probes); furthermore, no evidence of time-
dependent inhibition of 3A4 was observed in human liver
microsomes with the same probes. Further selectivity screening
performed within GlaxoSmithKline as well as a receptorgram
screen run at CEREP19 (Diversity profile) evidenced an excel-
lent overall selectivity profile on >200 targets with selectivity
falling below 30-fold only against R adrenergic receptors (pIC50
at rat native receptors, R1A=7.6, R1B=7.6); a follow-up study in
rabbit thoracic aorta preparations determined that 36 was
devoid of agonist activity at R1 receptors, but rather it demon-
strated a moderate functional antagonism of the phenylephrine-
induced contraction of rabbit aorta (pIC50=6.9). Taking into
account the low predicted systemic concentrations at therapeu-
tic doses, this degree of off-target activity was deemed tolerable
for progression.
Conclusion
In conclusion, a novel series of selective 5-HT1 antagonists
were prepared via modification of the benzoxazinone moiety
of a known dual acting 5-HT1 antagonist/SSRI structure. The
majority of compounds prepared showed potent affinity and
low intrinsic activities at the autoreceptors 5-HT1A, 5-HT1B
,
The susceptibility of compound 36 to the P-glycoprotein
(P-gp) efflux transporter was evaluated in MDCK cells express-
ing hMDR1. At 1 μM concentration, the ratio of the apparent
permeabilities measured from basolateral-to-apical (BA)
to apical-to-basolateral (AB) indicated that 36 is a moderate
P-gp substrate (BA/AB = 2.8; the BA/AB ratio drops to 1.6 in
the presence of the specific P-gp inhibitor GF120918).
The extent of plasma protein binding was determined
in rat, dog, and human plasma by equilibrium dialysis at a
and 5-HT1D and high selectivity overSerT. From among these
analogues, the cyclic urea derivative, 1-(3-{2-[4-(2-methyl-5-
quinolinyl)-1-piperazinyl]ethyl}phenyl)-2-imidazolidinone 36
(GSK163090), emerged due to its low hERG affinity and
excellent in vitro DMPK profile. The superior quality of 36
was further highlighted by its commendable in vivo pharma-
cokinetic profile in rat and its outstanding activity in the
5-HT1A PD model, where 50% efficacy was achieved at a
blood concentration of 3 ng/mL. On the basis of these results

Article
Journal of Medicinal Chemistry, 2010, Vol. 53, No. 23 8233
and its promising preclinical developability profile, com-
pound 36 was selected as an appropriate development candi-
date for progression toward clinical proof-of-concept studies.
Evidence supporting fast-onset antidepressant/anxiolytic
activity of compound 36 was obtained from both neurochem-
ical studies and validated rodent and primate animal models
of anxiety, which will be the subject of a separate publication.
DMPK Test Methods. Intrinsic Clearance (Clint) Assay. In-
trinsic clearance (Clint) values were determined in rat, dog, and
human liver microsomes. Test compounds (0.5 μM) were in-
cubated at 37 ꢀC for 30 min in 50 mM potassium phosphate
buffer (pH 7.4) containing 0.5 mg of microsomal protein/mL.
The reaction was started by addition of cofactor (NADPH;
8 mg/mL). The final concentration of solvent was 1% of the final
volume. At 0, 3, 6, 9, 15, and 30 min, an aliquot (50 μL) was
taken, quenched with acetonitrile containing an appropriate
internal standard, and analyzed by HPLC-MS/MS. The intrin-
sic clearance (Clint) was determined from the first-order elim-
ination constant by nonlinear regression using Grafit v5
(Erithacus software, UK), corrected for the volume of the
incubation and assuming 52.5 mg microsomal protein/g liver
for all species. Values for Clint were expressed as mL/min/g liver.
The lower limit of quantification of clearance was determined to
be when <15% of the compound had been metabolized by
30 min, and this corresponded to a Clint value of 0.5 mL/min/g
liver. The upper limit was 50 mL/min/g liver.
CYP450 Inhibition Assay. Inhibition potential (IC50) of test
compound for inhibition of human CYP1A2, 2C9, 2C19, 2D6,
and 3A4 was determined. A range of concentrations (0.1, 0.33, 1,
3.3, 10, 33, and 100 μM) of test compound prepared in methanol
were preincubated at 37 ꢀC for 10 min in 50 mM potassium
phosphate buffer (pH 7.4) containing 0.1, 0.16, 0.2, or 0.4 mg
recombinant human CYP450 microsomal protein mL-1
(Gentest Corporation, USA) and substrate. Following preincu-
bation, 25 μL mL-1 of a NADPH regenerating system (7.8 mg
glucose 6-phosphate, 1.7 mg NADP, and 6 U glucose 6-phos-
phate dehydrogenase mL-1 2% w/v NaHCO3) was added to
each well to start the reaction. Production of fluorescent meta-
bolite was then measured over a 10 min time-course using a
Spectrafluor plus plate reader (Tecan). The rate of metabolite
production (AFU/min) was determined for each concentration
of compound and converted to a percentage of the mean control
rate using Magellan v3.0 (Tecan software). The inhibitory
potential (IC50) was determined from the slope of the plot using
Grafit v4.12 (Erithacus software, UK). Miconazole was added
as a positive control to each plate.
Experimental Section
In Vitro Biological Test Methods. Receptor Affinities at Hu-
man Recombinant 5-HT1A, 5-HT1B, and 5-HT1D receptors. The
affinities of the compounds toward the 5-HT1A, 5-HT1B, and
5-HT1D receptors were determined by the following assay. CHO
cells expressing 5-HT1A receptors (4 ꢀ 107 cells/mL) were homo-
genized in Tris buffer and stored in 1 mL aliquots. CHO cells
expressing 5-HT1B receptors (4 ꢀ 107 cells/mL) were homogenized
in Tris buffer and stored in 1.5 mL aliquots. CHO cells expressing
5-HT1D receptors (1 ꢀ 108/mL) were homogenized in Tris buffer
and stored in 1 mL aliquots. Then 0.4 mL of a cell suspension is
incubated with [3H]-5-HT (4nM) for 5-HT1B/1D receptors and [3H]-
WAY100635 (1nM) for 5-HT1A receptors in Tris Mg HCl buffer
(pH 7.7) and test drug at 37 ꢀC for 45 min. Each test drug is tested at
10 concentrations (0.01-0.3 nM final concentration), with non-
specific binding defined using 0.01 mM 5-HT. The total assay
volume is 0.5 mL. Incubation is stopped by rapid filtration using a
Packard Filtermate and radioactivity measured by Topcount
scintillation counting. pKi values are calculated from the IC50
generated by an iterative least-squares curve fitting program.
Functional Activities at Human Recombinant 5-HT1A, 5-HT1B
,
and 5-HT1D Receptors. Intrinsic activities were determined
according to the following assay. HEK293 cell membranes
stably expressing human 5-HT1A receptors and CHO cell
membranes stably expressing human 5-HT1B or 5-HT1D
receptors are homogenized in HEPES/EDTA buffer and
stored in 1 mL aliquots, and [35S]-GTPγS binding studies
were carried out essentially as described by Lazareno et al.,20
with some minor modifications. Membranes from 106 cells
were preincubated at 30 ꢀC for 30 min in 20 mM HEPES
buffer (pH 7.4) in the presence of MgCl2 (3 mM), NaCl (100 mM),
GDP (10 μM), and ascorbate (0.2 mM), with or without test
compounds. The reaction was started by the addition of 50 μL
of [35S]-GTPγS (100 pM, assay concentration), followed by a
further 30 min incubation at 30 ꢀC. Nonspecific binding was
determined using nonradiolabeled GTPγS (20 μM) added
prior to the membranes. The reaction was terminated by
rapid filtration through Whatman GF/B grade filters. fol-
lowed by 5 ꢀ 1 mL washes with ice cold HEPES (20 mM)/
MgCl2 (3 mM) buffer. Radioactivity was measured using
liquid scintillation spectrometry.
CYP450 Inhibition Using Human Liver Microsomes. A range
of concentrations (0.1, 0.33, 1, 3.3, 10, 33, and 100 μM) of test
compound were prepared in methanol. These were preincubated at
37 ꢀC for 20 min in 50 mM potassium phosphate buffer (pH 7.4)
containing pooled human liver microsomal protein (0.1 mg/mL;
Xenotech) and CYP3A4 substrate (midazolam, atorvastatin or
nifedipine; 2.5, 10, or 50 μM, respectively). To start the reaction,
NADPH regenerating system (7.8 mg glucose 6-phosphate, 1.7 mg
NADP, and 6 units glucose-6-phosphate dehydrogenase/mL of 2%
(w/v) NaHCO3; 50 μL/mL) was added. Following a 5 min incuba-
tion, reactions were terminated with the addition of 250 μL of
acetonitrile.
Quantification of 10-hydroxy midazolam, o-hydroxy atorvas-
tatin, and oxidized nifedipine metabolites was carried out using
validated HPLC-MS analytical methods. Inhibition (IC50) was
determined using Grafit (Erithacus software, UK).
Functional Activity for Inhibition of the Serotonin Reuptake
Transporter (SerT). The efficacy to inhibit the reuptake of seroto-
nin was measured in a 5-HT uptake assay by measurement of
uptake of [3H]-5-HT into LLCPK cells expressing human serotonin
transporters. In brief, cells were harvested and plated onto 96-well
plates (10000 cells per well). Twenty-four hours later, cells were
washed twice with HBSSH (Hanks’ balanced salt solution þ20 mM
HEPES). Then 50 μL of test compound or vehicle was added to
each well and incubated for 10 min. Subsequently, [3H]-5-HT (final
concentration 25 nM) was added, and the test mixture was
incubated for a further 7 min. The reaction was terminated by
aspiration of test mixture, and the cells were washed six times with
HBSSH. Scintillation cocktail (50 μL, Microscint-20, Packard) was
added to the cells, and the top and bottom of the plate was sealed.
Plates were read, 30 min later, in a Packard TopCount instrument.
hERG [3H]-Dofetilide Binding Assay. hERG activity was
measured using [3H]-dofetilide binding in a scintillation proxi-
mity assay (SPA) format. The activity was measured with a
PerkinElmer Viewlux imager.
Metabolism-Dependent Inhibition of CYP3A4 in Human Liver
Microsomes. A range of concentrations (0.1, 0.33, 1, 3.3, 10, 33,
and 100 μM) of the test compound and troleandomycin (positive
control) were prepared in methanol. These were pre-incubated
at 37 ꢀC for 20 min in 50 mM potassium phosphate buffer
(pH 7.4) containing pooled human liver microsomal protein
(0.1 mg/mL; Xenotech) and NADPH regenerating system
(7.8 mg glucose 6-phosphate, 1.7 mg NADP, and 6 units
glucose-6-phosphate dehydrogenase/mL of 2% (w/v) NaHCO3;
50 μL/mL) [Cofactor preincubation samples] or CYP3A4 sub-
strate (midazolam, atorvastatin, or nifedipine; 2.5, 10, or 50 μM,
respectively) [substrate preincubation samples]. To start the reac-
tion, CYP3A4 substrate (midazolam, atorvastatin, or nifedipine;
2.5, 10, or 50 μM, respectively) was added to the cofactor pre-
incubation samples and NADPH regenerating system (50 μL/mL)

8234 Journal of Medicinal Chemistry, 2010, Vol. 53, No. 23
Leslie et al.
to the substrate preincubation samples. Following 5 min
incubation for midazolam and 10 min incubation for ator-
vastatin or nifedipine, reactions were terminated with the
addition of 250 μL of acetonitrile.
also included in the experiment as a positive control (0.03 mg/kg
sc 30 min before test). Eight to nine rats in each group of
treatment were used.
Drugs: Compound 36 was suspended in Methocel 0.5% (w/v,
HPCM Colorcon, Dow Chemical Company, Midland, MI). 8-OH-
DPAT was purchased by Sigma (Italy) and dissolved in saline
before use. WAY-100,635 (N-{2-[4-(2-methoxyphenyl)-1-pipera-
ziny]ethyl}-N-(2-pyridinyl) cyclohexane-carboxamide trihydro-
chloride) was synthesized in-house and dissolved in sterile water
before use. All compounds were prepared with correction for salt
form such that doses cited refer to mg/kg of active principle.
Chemistry. General Methods. Proton magnetic resonance
(NMR) spectra were recorded either on Varian instruments at
300, 400, or 500 MHz, or on a Bruker instrument at 300 MHz.
Chemical shifts are reported in ppm (δ) using the residual
solvent line as internal standard. Splitting patterns are designed
as s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet; b,
broad. The NMR spectra were recorded at a temperature ranging
from 25 to 90 ꢀC. When more than one conformer was detected,
the chemical shifts for the most abundant one was reported.
Mass spectra (MS) were typically taken on a 4 II triple quadru-
pole mass spectrometer (Micromass UK) or on a Agilent MSD
1100 mass spectrometer, operating in ES (þ) and ES(-) ioniza-
tion mode or on an Agilent LC/MSD 1100 mass spectrometer,
operating in ES (þ) and ES (-) ionization mode coupled with
HPLC instrument Agilent 1100 series [LC/MS-ES (þ): analysis
performed on a Supelcosil ABZ þPlus (33 mm ꢀ 4.6 mm, 3 μm)
(mobile phase, 100% [water þ 0.1% HCO2H] for 1 min, then
from 100% [water þ 0.1% HCO2H] to 5% [water þ 0.1%
HCO2H] and 95% [CH3CN] in 5 min, finally under these
conditions for 2 min; T=40 ꢀC; flux=1 mL/min; LC/MS-ES:
analysis performed on a Supelcosil ABZ þPlus (33 mmꢀ4.6 mm,
3 μm) (mobile phase: 100% [water þ0.05% NH3] for 1 min, then
from 100% [water þ0.05% NH3 to 5% [water þ0.05% NH3]
and 95% [CH3CN] in 5 min, finally under these conditions for 2
min; T = 40 ꢀC; flux = 1 mL/min]]; in the mass spectra, only one
peak in the molecular ion cluster is reported.
Quantification of 10-hydroxy midazolam, o-hydroxy atorvas-
tatin, and oxidized nifedipine metabolites was carried out using
validated HPLC-MS analytical methods. Inhibition (IC50
)
was determined using Grafit (Erithacus software, UK) and
TDI assessed, comparing the difference in IC50 between the
cofactor and substrate preincubation samples for each CYP3A4
substrate.
Rat Pharmacokinetics. Test compounds were administered to
male Sprague-Dawley rats as cassette. The compounds were
dosed intravenous (0.5 mg/kg, 2 mL/kg, 2.5% DMSO in
glucosate solution; n=3 for the iv pharmacokinetic study and
n=3 for the brain penetration study) and po (1 mg/kg, 10 mL/
kg, 1% DMSO in aqueous methocel 0.5%, n = 3).
In the po and iv pharmacokinetic studies, blood samples were
collected at intervals up to 24 h after each administration. In the
brain penetration study, at 1 h after intravenous dosing, animals
were anaesthetised using carbon dioxide. A blood sample was
collected via a heart puncture and the brain removed.
Blood and brain samples were analyzed for test compounds
using a method based on protein precipitation followed by LC-
MS/MS analysis.
In Vitro P-Glycoprotein Assay. MDCK cells expressing hu-
man MDR1 were used to determine whether test compounds are
substrates for human P-glycoprotein (P-gp). Compounds were
tested in duplicate in two directions (apical-to-basolateral and
basolateral-to-apical) and in the presence and absence of
GF120918 (2 μM), a specific inhibitor of P-gp. Amprenavir (1
and 0.5 μM), a known P-gp substrate, was included as positive
control. The apparent permeability value (Papp) was measured
from the apical (which represents the blood lumen) to the
basolateral (which simulates the brain side) compartment
(Papp AB) and from basolateral to apical side (Papp BA) in order
to determine the BA/AB ratio.
DAD chromatographic traces, mass chromatograms, and
mass spectra were taken on a UPLC/MS Acquity system
coupled with a Micromass ZQ mass spectrometer operating in
ESI positive or negative. The phases used were: (A) H2O/ACN
95/5 þ 0.1% TFA; (B) H2O/ACN 5/95 þ 0.1% TFA. The
gradient was: t = 0 min) 95%A 5%B, t = 0.25) 95%A 5%B, t =
3.30) 100%B, t = 4.0) 100%B, followed by 1 min of recondi-
tioning. Flash silica gel chromatography was carried out on
silica gel 230-400 mesh (supplied by Merck AG Darmstadt,
Germany) or over Varian Mega Be-Si prepacked cartridges or
over prepacked Biotage silica cartridges. SPE-SCX cartridges
were ion exchange solid phase extraction columns supplied by
Varian. The eluent used with SPE-SCX cartridges was metha-
nol, followed by 2N ammonia solution in methanol. In a number
of preparations, purification was performed using either Bio-
tage manual flash chromatography (Flashþ) or automatic flash
chromatography (Horizon, SP1) systems. All these instruments
work with Biotage Silica cartridges. SPE-Si cartridges were silica
solid-phase extraction columns supplied by Varian. Microwave
reactions were carried out in a Personal Chemistry Emrys
Optimiser (300 W). All reactions were carried out under anhy-
drous nitrogen or argon atmosphere using standard Schlenk
techniques. Most chemicals and solvents were analytical grade
and used without further purification.
A compound is considered to be a substrate for P-gp when the
BA/AB ratio in the absence of GF120918 is greater than 1.8 and
is significantly reduced in the presence of GF120918.
In Vivo Biological Test Methods. All the work involving
animals was carried out in accordance with European directive
86/609/EEC governing animal welfare and protection, which is
acknowledged by Italian Legislative Decree no. 116, 27 Janu-
ary 1992, and according to internal review performed by the
GlaxoSmithKline Committee on Animal Research & Ethics
(CARE) and to the company Policy on the Care and Use of
Laboratory Animals.
Adult male Sprague-Dawley rats (Charles River, Italy) were
group-housed upon arrival and left to acclimatize for at least 5 days
in a room controlled for temperature (23 ( 1 ꢀC), humidity (60%),
and lighting (12 h light-dark cycle; lights on 0600-1800 h) with ad
libitum access to food pellets (Riepper, Italy) and tap water.
Rat Hyperlocomotion 5-HT1A Pharmacdynamic Model. Rats
(250-350 g at test) were used. Rat locomotory activity was
assessed as the total distance (cm) traveled by each rat in the test
arena over a 30 min period using Digiscan analyzer system
(Omnitech, model RXYZCM-8, Columbus, OH). Rats were
placed individually into clear plexiglas boxes, measuring 40 cmꢀ
40 cm ꢀ 30.5 cm and covered with a perforated plexiglas lid.
Infrared monitoring sensors were located around the perimeter
walls. Data were collected and analyzed by a Digiscan analyzer
(Omnitech, model DCM-4, Columbus, OH), which in turn
transferred information to a computer. Total distance was
recorded during 30 min test period.
The purity of the compounds reported in the manuscript was
established through HPLC methodology. All the compounds
reported in the manuscript have a chemical purity g95%.
Chemistry. General Procedures. The general synthetic scheme
used for the preparation of the reported compounds is shown in
Scheme 1. Experimental procedures and analytical data for com-
pounds 5-41 are described below.
Rats were treated orally (5 mL/kg, body weight) with vehicle
or compound 36 at 0.03, 0.1, or 0.3 mg/kg 60 min before a
subcutaneous (sc, 2 mL/kg) injection of 0.2 mg/kg of 8-OH-
DPAT, then immediately assessed for their locomotor activity.
The standard 5-HT1A receptor antagonist WAY-100,635 was
2-Methyl-5-quinolinyl Trifluoromethanesulfonate (5). A solu-
tion of 2-methyl-quinolin-5-ol (2.5 g; 1 equiv) in dichloromethane

Article
Journal of Medicinal Chemistry, 2010, Vol. 53, No. 23 8235
(25 mL) and pyridine (6.4 mL; 5 equiv) was cooled to 0 ꢀC, and
trifluoromethanesulfonic anhydride (4.2 mL; 1.6 equiv) was
added dropwise over 10 min. The reaction mixture was stirred
under an inert atmosphere at rt for 1 h, then poured into
water (20 mL) and extracted into ethyl acetate (3ꢀ15 mL).
The organic layers were combined, dried over Na2SO4, and
concentrated under reduced pressure. The crude was puri-
fied by flash chromatography, eluting with ethyl acetate/cyclohex-
ane (4/6), affording the title compound in 92% yield (4.2 g). MS
(ES) m/z: 292.3 [MHþ]. C11H8F3NO3S requires 291. 1H NMR
(300 MHz, DMSO-d6) δ (ppm): 8.05 (d, 1 H), 7.85 (d, 1 H),
7.64 (t, 1H), 7.48 (d, 1 H), 7.43 (d, 1 H), 2.48 (s, 3 H).
3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}aniline (9). A
solution of intermediate 8 (0.14 g; 1 equiv) in methanol (3 mL) was
added dropwise to a suspension of iron powder (0.07 g; 3.2 equiv)
and ammonium chloride (0.1 g; 5.3 equiv) in water (3 mL). The
reactants were heated at reflux for 8 h, adding additional amounts of
iron powder (total 0.07 g; 3.2 equiv) and ammonium chloride (total
0.1 g; 5.03 equiv) in 3 portions during the reaction. The reaction
mixture was filtered using a Millipore filter. The filtrate was
concentrated under reduced pressure, diluted with water (5 mL) and
a saturated aqueous solution of sodium hydrogen carbonate
(2 mL), extracted into ethyl acetate (3 ꢀ 5 mL), dried over Na2SO4,
and concentrated under reduced pressure, obtaining the title com-
pound in 84% yield (0.11 g). MS (ES) m/z: 347.4 [MH]þ. C22H26N4
requires 346. 1H NMR (300 MHz, CDCl3) δ (ppm): 8.35 (d, 1 H),
7.70 (d, 1 H), 7.55 (t, 1 H), 7.25 (d, 1 H), 7.08 (m, 2 H), 6.65 (md,
1H),6.55(m,2H),3.65(bs,2H),3.15(t,4H),2.80(m,4H),2.75(s,
3 H), 2.70 (m, 4 H).
1,1-Dimethylethyl 4-(2-methyl-5-quinolinyl)-1-piperazinecar-
boxylate (6). tert-Butyl 1-piperazine carboxylate (1.6 g; 1.2
equiv), cesium carbonate (1.7 g; 1.5 equiv), palladium acetate
(0.33 g; 0.14 equiv), and 2,20-bis(diphenylphosphino)-1,10-bi-
naphthyl (0.97 mg; 0.15 equiv) were added to a solution of
intermediate 5 in toluene (20 mL) under an inert atmosphere.
The reaction mixture was stirred at reflux under nitrogen for 8 h.
The reaction was quenched at room temperature using a satu-
rated aqueous solution of ammonium chloride (15 mL) and
extracted into ethyl acetate (3 ꢀ 20 mL). The organic layers were
combined, dried over Na2SO4, and concentrated under reduced
pressure. The crude was purified by flash chromatography,
eluting with ethyl acetate/cyclohexane (3/7), affording the title
compound in 62% yield (1.4 g). MS (ES) m/z: 328.4 [MH]þ.
N-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-
methanesulfonamide (10). Methanesulfonyl chloride (8 μL; 1.2 equiv)
was added dropwise to a solution of intermediate 9 (0.03 g; 1 equiv)
in pyridine (0.5 mL). The reaction was stirred at rt overnight. The
reaction mixture was concentrated under reduced pressure, diluted
with water (1 mL) and a saturated aqueous solution of sodium
hydrogen carbonate (1 mL), extracted into dichloromethane (3 ꢀ
2 mL), dried over Na2SO4, and concentrated under reduced pressure.
The crude was purified by flash chromatography, eluting with a
gradient from dichloromethane to dichloromethane/MeOH (98/2),
affording the title compound in 44% yield (0.016 g). MS (ES) m/z:
C
19H25N3O2 requires 327. 1H NMR (500 MHz, CDCl3)
δ (ppm): 8.40 (d, 1 H), 7.76 (d, 1 H), 7.61 (t, 1 H), 7.29 (d,
1 H), 7.06 (d, 1 H), 3.69 (bs, 4 H), 3.03 (bs, 4 H), 2.74 (s, 3 H),
1.51 (s, 9 H).
1
425.4 [MH]þ. C23H28N4O2S requires 424. H NMR (300 MHz,
MeOD) δ (ppm): 8.40 (d, 1 H), 7.55 (m, 2 H), 7.30 (d, 1 H), 7.15
(t, 1 H), 7.10 (m, 2 H), 6.90 (bt, 2 H), 3.05 (bt, 4 H), 2.85 (s, 3 H),
2.83-2.63 (bm, 8 H), 2.60 (s, 3 H).
2-Methyl-5-(1-piperazinyl)quinoline (7). Intermediate 6 (1.1 g)
in a 25% solution of trifluoroacetic acid in dichloromethane
(10 mL) was stirred at rt under an inert atmosphere for 3 h. The
reaction mixture was concentrated under reduced pressure and
desalted by means of a 20 g SCX cartridge, affording the title
compound in 96% yield (0.74 g). MS (ES) m/z: 228.4 [MH]þ.
C14H17N3 requires 227. 1H NMR (300 MHz, DMSO-d6)
δ (ppm): 8.34 (d, 1 H), 7.57 (m, 2 H), 7.35 (m, 1 H), 7.06 (m,
1 H), 2.93 (bm, 8 H), 2.62 (s, 3 H).
2-(3-Nitrophenyl)ethyl methanesulfonate used in the synthesis
of 8 was prepared as follows: Methanesulfonyl chloride (0.28 mL)
was added dropwise to a stirred solution of 2-(3-nitrophe-
nyl)ethanol (0.5 g; 1 equiv) in dichloromethane (3 mL) and
triethylamine (0.5 mL; 1.2 equiv) at 0 ꢀC under an inert atmosphere.
The solution was allowed to reach rt and stirred for 5 h. The
reaction mixture was diluted with water (3 mL) and extracted into
dichloromethane (3 ꢀ 3 mL). The organic layers were combined,
dried over Na2SO4, and concentrated under reduced pressure. The
crude was purified by flash chromatography, eluting with a gra-
dient from dichloromethane to dichloromethane/MeOH (98/2),
affording the title compound in 84% yield (0.62 g). 1H NMR (300
MHz, CDCl3) δ (ppm): 8.15 (m, 2 H), 7.53 (m, 2 H), 4.45 (t, 2 H),
3,15 (t, 2H), 2.92 (s, 3 H).
2-Methyl-5-{4-[2-(3-nitrophenyl)ethyl]-1-piperazinyl}quino-
line (8). N,N-Diisopropylethylamine (0.8 mL; 5 equiv) was
added to a solution of intermediate 7 (0.2 g; 1 equiv) and 2-(3-
nitrophenyl)ethyl methanesulfonate (0.22; 1 equiv) in dimethyl-
formamide (1.5 mL). The reaction mixture was heated to 100 ꢀC
for 10 h. The dark solution was concentrated under reduced
pressure, diluted with water (3 mL) and brine (1 mL), and
extracted into ethyl acetate (3 ꢀ 3 mL). The organic layers were
combined, dried over Na2SO4, and concentrated under reduced
pressure. The crude was purified by flash chromatography,
eluting with a gradient from dichloromethane to dichloro-
methane/MeOH (98/2), affording the title compound in 64%
yield (0.21 g). MS (ES) m/z: 377.4 [MH]þ. C22H24N4O2 requires
376. 1H NMR (300 MHz, CDCl3) δ (ppm): 8.35 (d, 1 H), 8.11 (s,
1 H), 8.05 (d, 1 H), 7.70 (d, 1 H), 7.55 (m, 2 H), 7.45 (t, 1 H), 7.25
(m, 1 H), 7.05 (d, 1 H), 3.10 (mt, 4 H), 2.95 (bm, 2 H), 2.75 (bm,
6 H), 2.70 (s, 3 H).
N-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-1-
propanesulfonamide (11). The title compound was prepared in 62%
yield using a similar procedure to compound 10 starting from
intermediate 9 and propanesulfonyl chloride. MS (ES) m/z: 453.4
[MH]þ. C25H32N4O2S requires 452. 1H NMR (300 MHz, CDCl3) δ
(ppm):8.35(d,1H),7.70(d,1H),7.60(t,1H),7.30(m,2H),7.1(m,
2H), 7.01 (d, 1 H), 3.30 (bm, 6 H), 2.80 (bm, 6 H), 2.60 (s, 3 H), 1.80
(m, 2 H), 1.0 (t, 3 H).
General Procedure for the Preparation of Amides and Their
Corresponding Dihydrochloride Salts Starting from Intermediate
9. Method A. Triethylamine or diisopropylethylamine (1.7 equiv)
and then an acyl chloride (1.5 equiv) were added dropwise to a
stirred solution of intermediate 9 (1 equiv) in dichloromethane at
room temperature under an inert atmosphere. The reaction was left
under stirring for 16 h. The mixture was then washed with a
saturated aqueous solution of NH4Cl, a saturated aqueous solu-
tion of NaHCO3, brine, dried over Na2SO4, and the solvent was
removed under reduced pressure. The crude material was purified
on SPE cartridge (Silica) using as eluent a gradient from dichloro-
methane/MeOH 99/1 to dichloromethane/MeOH 98/2, affording
the final compound (yields ranged from 30 to 80%).
Method B. EDC HCl (1.5 equiv) and HOBt (1.5 equiv) were
3
added sequentially to a stirred solution of a carboxylic acid (1.5
equiv) in dichloromethane/dimethylformamide (1/1) at room
temperature. The reaction mixture was left under stirring for 30
min, and then intermediate 9 (1 equiv) dissolved in dichloro-
methane/dimethylformamide (1/1) was added dropwise. The
solution was stirred for 16 h and then diluted with dichloro-
methane and washed with a saturated aqueous solution of
NaHCO3 and brine and then dried over Na2SO4. The solution
was concentrated under reduced pressure, and the residual
solvent was removed by means of an SCX cartridge. The crude
material was purified on SPE cartridge (Silica) eluting from a
gradient from dichloromethane/MeOH 99/1 to dichloromethane/
MeOH 98/2, affording the final compound (yields ranged from 20
to 96%).
The free base could be converted into its dihydrochloride salt
by dissolving the compound in dichloromethane and adding a

8236 Journal of Medicinal Chemistry, 2010, Vol. 53, No. 23
Leslie et al.
1 M ethereal solution of HCl (2.1 equiv) dropwise. A yellow
solid precipitated and the suspension was stirred for 15 min. The
solvent was removed under reduced pressure, affording a crude
material which was triturated with Et2O. The final compound
was then recovered by filtration (yield quantitative).
4-Fluoro-N-(3-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]ethyl}-
phenyl) Benzamide Dihydrochloride Salt (19). The title compound
was prepared in 82% yield according to the general procedure for
the preparation of the amides (method B) starting from intermedi-
ate 9 and 4-fluorobenzoic acid. HPLC/MS (ES/þ): tR = 6.45 min;
assay 98.2% a/a; m/z: 469 [MHþ]. C29H29FN4O requires 468. 1H
NMR (400 MHz, DMSO-d6) δ (ppm): 11.29 (br s, 1H), 10.36 (s,
1H), 8.96 (br s, 1 H), 8.08 (m, 2H), 7.99 (br s, 1H), 7.86 (br s, 1H),
7.62 (d, 1H), 7.47 (br d, 1H), 7.40 (m, 3H), 7.09 (d, 1H), 3.70-3.30
(m, 10H), 3.18 (dd, 2H), 2.93 (br s, 3H).
N-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-
acetamide (12). The title compound was prepared in 52% yield
according to the general procedure for the preparation of the amides
(method A) starting from intermediate 9 and acetyl chloride. MS
1
(ES) m/z: 389 [MH]þ. C24H28N4O requires 388. H NMR (500
2-(Methyloxy)-N-(3-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]-
ethyl}phenyl) Benzamide Dihydrochloride Salt (20). The title com-
pound was prepared in 85% yield according to the general proce-
dure for the preparation of the amides (method B) starting from
intermediate 9 and 2-(methyloxy)benzoic acid. HPLC/MS (ES/þ):
tR= 6.54 min; assay >99% a/a; m/z: 481 [MHþ]. C30H30N4O2
requires 480. 1H NMR (400 MHz, DMSO-d6) δ (ppm): 11.13 (br s,
1H), 10.17 (s, 1H), 8.93 (br s, 1H), 7.97 (s, 2H), 7.86-7.78 (br s, 1H),
7.64 (dd, 1H), 7.58-7.50(m, 2H), 7.47 (br s, 1H), 7.36 (t, 1H), 7.21
(d, 1H), 7.09 (dt, 1H), 7.07 (d, 1H), 3.92 (s, 3H), 3.76 (d, 2H),
3.70-3.30 (m, 8H), 3.17 (m, 2H), 2.91(br s, 3H).
3-(Methyloxy)-N-(3-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]-
ethyl}phenyl) Benzamide Dihydrochloride Salt (21). The title com-
pound was prepared in 83% yield according to the general proce-
dure for the preparation of the amides (method B) starting from
intermediate 9 and 3-(methyloxy)benzoic acid. HPLC/MS (ES/þ):
tR= 6.39 min; assay >99% a/a; m/z: 481[MHþ]. C30H30N4O2
requires 480. 1H NMR (400 MHz, DMSO-d6) δ (ppm): 11.88 (br s,
1H), 10.30 (s, 1H), 8.86 (br s, 1H), 7.91 (br s, 2H), 7.87 (br s, 1H),
7.78 (br s, 2H), 7.63 (dd, 1H), 7.56 (d, 1H), 7.51 (m, 1H), 7.47 (t,
1H), 7.47 (br s, 1H), 7.38 (t, 1H), 7.19 (dm, 1H), 7.09 (d, 1H), 3.86
(s, 3H), 3.76 (d, 2H), 3.70-3.25 (m, 8H), 3.17 (m, 2H), 2.88 (br s,
3H).
4-(Methyloxy)-N-(3-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]-
ethyl}phenyl) Benzamide Dihydrochloride Salt (22). The title com-
pound was prepared in 83% yield according to the general proce-
dure for the preparation of the amides (method B) starting from
intermediate 9 and 4-(methyloxy)benzoic acid. HPLC/MS (ES/þ):
tR = 6.21 min; assay >99% a/a; m/z: 481 [MHþ]. C30H30N4O2
requires 480. 1H NMR (500 MHz, DMSO-d6) δ (ppm): 11.09 (br s,
1H), 10.16 (s, 1H), 8.91 (br s, 1H), 7.97 (d, 2H), 7.94 (br s, 2H), 7.84
(s, 1H), 7.81 (br s, 1H), 7.60 (d, 1H), 7.44 (br s, 1H), 7.34 (t, 1H),
7.05 (m, 3H), 3.83 (s, 3H), 3.74 (br d, 2H), 3.60-3.40 (m, 6H), 3.33
(br t, 2H), 3.14 (dd, 2H), 2.89 (br s, 3H).
N-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-2-
pyrazine Carboxamide (23). The title compound was prepared in
89% yield according to the general procedure for the preparation of
the amides (method B) starting from intermediate 9 and 2-pyrazi-
necarboxylic acid. MS (ES/þ) m/z: 453 [MHþ]. C27H28N6O re-
quires 452. 1H NMR (300 MHz, CDCl3) δ (ppm): 9.65 (s, 1H), 9.50
(m, 1H), 8.80 (d, 1H), 8.60 (t, 1H) 8.38 (d, 1H), 7.75 (d, 1H), 7.70 (d,
1H), 7.58 (t, 1H), 7.55 (dd, 1H), 7.35 (t, 1H), 7.28 (d, 1H), 7.08 (m,
2H), 3.15 (br s, 4H) 2.95-2.70 (m, 8H), 2.70 (br s, 3H).
MHz, DMSO-d6) δ(ppm):9.84 (s, 1H), 8.33(d, 1H), 7.58 (m, 2H),
7.46(s, 1H), 7.39(m, 2H), 7.19(t, 1H), 7.10(dd, 1H), 6.92(d, 1H),
3.03 (bm, 4 H), 2.73 (bm, 6 H), 2.62 (s þ bm, 5 H), 2.02 (s, 3 H).
N-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-
propanamide (13). The title compound was prepared in 73% yield
according to the general procedure for the preparation of the
amides (method A) starting from intermediate 9 and propanoyl
chloride. MS (ES/þ) m/z: 403 [MHþ]. C25H30N4O requires 402.
1H NMR (300 MHz, CDCl3) δ (ppm): 8.35 (d, 1H), 7.70 (d, 1H),
7.55 (t, 1H), 7.50 (br s, 1H), 7.25 (m, 3H), 7.12 (br, 1H), 7.07 (d,
1H), 6.98 (br d, 1H), 3.20 (br m, 4H), 3.00-2.75 (br m, 8H), 2.73
(s, 3H), 2.37 (q, 2H), 1.23 (t, 3H).
2-Methyl-N-(3-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]ethyl}-
phenyl) propanamide (14). The title compound was prepared in 81%
yield according to the general procedure for the preparation of the
amides (method A) starting from intermediate 9 and 2-methylpro-
panoyl chloride. MS (ES/þ) m/z: 417 [MHþ]. C26H32N4O requires
416. 1H NMR (300 MHz, CDCl3) δ (ppm): 8.35 (d, 1H), 7.70 (d,
1 H), 7.55 (m, 2H), 7.25 (m, 3H), 7.13 (br s, 1H), 7.08 (d, 1H), 6.98
(br d, 1H), 3.20 (br m, 4H), 3.00-2.75 (br m, 8 H), 2.73 (s, 3H), 2.48
(m, 1H), 1.25 (d, 6H).
2,2-Dimethyl-N-(3-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]-
ethyl}phenyl) propanamide (15). The title compound was prepared
in 66% yield according to the general procedure for the prepara-
tion of the amides (method A) starting from intermediate 9 and
2,2-dimethylpropanoyl chloride. MS (ES/þ) m/z: 431 [MHþ].
C27H34N4O requires 430. 1H NMR (300 MHz, CDCl3) δ (ppm):
8.35 (d, 1H), 7.70 (d, 1H), 7.55 (t, 2H), 7.30-7.20 (m, 4H), 7.10 (d,
1H), 7.00 (m, 1H), 3.20 (br s, 4H), 2.85 (br s, 8H), 2.70 (s, 3H), 1.30
(s, 9H).
N-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-
benzamide (16). The title compound was prepared in 60% yield
according to the general procedure for the preparation of the
amides (method A) starting from intermediate 9 and benzoyl
chloride. MS (ES/þ) m/z: 451 [MHþ]. C29H30N4O requires 450.
1H NMR (300 MHz, CDCl3) δ (ppm): 8.35 (d, 1H), 7.87 (m, 2H),
7.80 (br s, 1H), 7.72 (d, 1H), 7.65 (br s, 1H), 7.6-7.4 (m, 5H), 7.30
(t, 1H), 7.27 (m, 1H), 7.08 (d, 1H), 7.05 (d, 1H), 3.18 (br s, 4H),
3.00-2.75 (br m, 8H), 2.72 (s, 3H).
2-Fluoro-N-(3-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]ethyl}-
phenyl) Benzamide Dihydrochloride Salt (17). The title compound
was prepared in 96% yield according to the general procedure for
the preparation of the amides (method B) starting from intermedi-
ate 9 and 2-fluorobenzoic acid. MS (ES/þ) m/z: 469 [MHþ].
2-Methyl-N-(3-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]ethyl}-
phenyl)-1,3-thiazole-4-carboxamide Dihydrochloride Salt (24). The
title compound was prepared in 52% yield according to the general
procedure for the preparation of the amides (method B) starting
from intermediate 9 and 2-methyl-1,3-thiazole-4-carboxylic acid.
MS (ES/þ) m/z: 472 [MHþ]. C27H29N5OS requires 471. 1H NMR
(400 MHz, DMSO-d6) δ (ppm): 10.70 (br s, 1H), 10.15 (s, 1H), 8.77
(brs,1H), 8.26(s,1H),7.87(brs,1H), 7.75-7.85 (m, 2H), 7.39 (br s,
1H), 7.34 (t, 1H), 7.06 (d, 1H), 3.80-3.20 (m, 10H), 3.12 (dd, 2H),
2.83 (br s, 3H), 2.76 (s, 3H).
4-Methyl-N-(3-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]ethyl}-
phenyl)-1,3-thiazole-5-carboxamide Dihydrochloride Salt (25). The
title compound was prepared in 46% yield according to the general
procedure for the preparation of the amides (method B) starting
from intermediate 9 and 4-methyl-1,3-thiazole-5-carboxylic acid.
MS (ES/þ) m/z: 472 [MHþ]. C27H29N5OS requires 471. 1H NMR
(400 MHz, DMSO-d6) δ (ppm): 10.83 (br s, 1H), 10.28 (s, 1H), 9.13
1
C29H29FN4O requires 468. H NMR (500 MHz, DMSO-d6) δ
(ppm):11.00(brs, 1H), 10.46(s. 1H), 8.80 (brs, 1H), 8.00-7.72(m,
4H), 7.65 (t, 1H), 7.58 (q, 1H), 7.52 (d, 1H), 7.73 (br s, 1H),
7.37-7.32 (m, 3H), 7.08 (d, 1H), 3.74 (d, 2H), 3.7-3.3 (m, 9H),
3.15 (m, 2H), 2.88 (s, 3H).
3-Fluoro-N-(3-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]ethyl}-
phenyl) Benzamide Dihydrochloride Salt (18). The title compound
was prepared in 91% yield according to the general procedure for
the preparation of the amides (method B) starting from intermedi-
ate 9 and 3-fluorobenzoic acid. HPLC/MS (ES/þ): tR= 6.45 min;
assay >99% a/a; m/z: 469 [MHþ]. C29H29FN4O requires 468. 1H
NMR (400 MHz, DMSO-d6) δ (ppm): 11.18 (br s, 1H), 10.41 (s,
1H), 8.94 (br s, 1H), 7.97 (br s, 2H), 7.87 (br s, 2H), 7.80 (m, 2H),
7.62 (m, 2H), 7.48 (m, 2H), 7.10 (d, 1H), 3.80-3.30 (m, 10H), 3.18
(m, 2H), 2.92 (br s, 3H).

Article
Journal of Medicinal Chemistry, 2010, Vol. 53, No. 23 8237
(s, 1H), 8.86 (br s, 1H), 7.90 (br s, 2H), 7.80-7.74 (br s-s, 2H), 7.50
(d, 1H), 7.43 (br s, 1H), 7.35 (t, 1H), 7.08 (d, 1H), 3.9-3.2 (m, 10H),
3.13 (dd, 2H), 2.87 (br s, 3H), 2.61 (s, 3H).
1 H), 7.26 (m, 2 H), 7.20 (dd, 1 H), 7.07 (dd, 1 H), 6.98 (m, 1 H),
6.90 (m, 1 H), 3.69 (d, 2 H), 3.5-3.2(m, 8 H), 3.09 (m, 2 H), 2.82
(bs, 3 H).
N-(3-Fluorophenyl)-N0-(3-{2-[4-(2-methyl-5-quinolinyl)-1-pipera-
zinyl]ethyl}phenyl)urea Dihydrochloride (31). The title compound
was prepared in 48% yield according to the general procedure for
the preparation of ureas (method C) starting from intermediate 9
and 1-fluoro-3-isocyanatobenzene. MS (ES/þ) m/z: 484 [MHþ]
General Procedure for the Preparation of Ureas and Their
Corresponding Dihydrochloride Salts Starting from Intermediate
9. Method C. An isocyanate was added to a stirred solution of
intermediate 9 (1 equiv) in dichloromethane at room tempera-
ture under an inert atmosphere, and the reaction was left under
stirring for 16 h. The solution was then poured into water and
extracted with dichloromethane, the organic phase was dried
over Na2SO4, and the solvent was removed under reduced
pressure. The crude material was purified on SPE cartridge
(Silica) using a gradient from dichloromethane to dichloro-
methane/MeOH 95/5 as eluent, affording the final compound
(yields ranged from 30 to 80%).
The free base could be converted into its dihydrochloride salt
by dissolving the compound in dichloromethane and adding a
1M ethereal solution of HCl (2.1 equiv) dropwise. A yellow solid
precipitated and the suspension was stirred for 15 min. The
solvent was removed under reduced pressure, affording a crude
material which was triturated with Et2O. The final compound
was then recovered by filtration (yield quantitative).
N-Ethyl-N0-(3-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]ethyl}-
phenyl)urea Dihydrochloride (26). The title compound was prepared
in 95% yield according to the general procedure for the preparation
of ureas (method C) starting from intermediate 9 and isocyana-
toethane. MS (ES/þ) m/z: 418 [MHþ] C25H31N5O requires 417. 1H
NMR (400 MHz, DMSO-d6) δ (ppm): 10.89 (bs, 1 H), 8.60 (bs,
1 H), 8.90 (s, 1 H), 7.92 (bs, 2 H), 7.80 (bs, 1 H), 7.44 (s, 2 H), 7.19
(m, 2 H), 6.81 (m, 1 H), 3.71 (d, 2 H), 3.6-3.2 (m, 10 H), 3.07 (m,
2 H), 2.87 (bs, 3 H), 1.02 (t, 3 H).
N-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-
N0-propylurea dihydrochloride (27). The title compound was pre-
pared in 53% yield according to the general procedure for the
preparation of ureas (method C) starting from intermediate 9 and
1-isocyanatopropane. MS (ES/þ) m/z: 432 [MHþ] C26H33N5O
requires 431. 1H NMR (400 MHz, DMSO-d6) δ (ppm): 10.5 (bs,
1 H), 8.75 (bs, 1 H), 8.54 (s, 1H), 7.83 (bs, 2 H), 7.7 (bs, 1 H), 7.45
(s, 1 H), 7.38 (bs, 1 H), 7.18 (m, 2 H), 6.81 (d, 1 H), 6.23 (bt, 1 H),
3.7-3.25 (bd, 4 H), 3.6-3.3 (m, 4 H), 3.4-3.02 (m, 6 H), 2.81 (bs,
3 H), 1.41 (m, 2 H), 0.85 (t, 3 H).
1
C29H30FN5O requires 483. H NMR (400 MHz, DMSO-d6) δ
(ppm): 10.7 (bs, 1 H), 9.47 (s, 1 H), 9.24 (s, 1H), 8.75 (bs, 1 H), 7.81
(bs, 2 H), 7.68 (bs, 1H), 7.50 (dþbs, 2 H), 7.44 (bs, 1 H), 7.31 (t,
1 H), 7.3-7.24 (m, 2 H), 7.09 (d, 1 H), 6.89 (d, 1 H), 6.74 (td, 1 H),
3.7-3.2(m, 10 H), 3.07 (m, 2 H), 2.8 (bs, 3 H).
N-(4-Fluorophenyl)-N0-(3-{2-[4-(2-methyl-5-quinolinyl)-1-pipera-
zinyl]ethyl}phenyl)urea Dihydrochloride (32). The title compound
was prepared in 64% yield according to the general procedure for
the preparation of ureas (method C) starting from intermediate 9
and 1-fluoro-4-isocyanatobenzene. MS (ES/þ) m/z: 484 [MHþ].
1
C29H30FN5O requires 483. H NMR (400 MHz, DMSO-d6) δ
(ppm): 10.49 (bs, 1 H), 9.40 (s, 1 H), 8.96 (s, 1H), 8.77 (bs, 1 H), 7.83
(bs, 2 H), 7.71 (bs, 1H), 7.51(bs, 1 H), 7.45 (dd, 2 H), 7.37 (bs, 1 H),
7.25 (bd, 2 H), 7.10 (t, 2 H), 6.90 (bt, 1 H), 3.8-3.2(m, 10 H), 3.06
(dd, 2 H), 2.81 (bs, 3 H).
General Procedure for the Preparation of Carbamates and
Their Corresponding Dihydrochloride Salts Starting from Inter-
mediate 9. Method D. Diisopropylethylamine (1.5 equiv) and a
chloroformate (1.2 equiv) were added sequentially to a stirred
solution of intermediate 9 (1 equiv) in dichloromethane at 0 ꢀC.
The solution was stirred for 1 h at room temperature and then
diluted with dichloromethane and washed with a saturated
aqueous solution of NH4Cl and brine and then dried over
Na2SO4. The solution was concentrated under reduced pressure.
The crude material was purified on SPE cartridge (Silica) eluting
with a gradient from dichloromethane/MeOH 99/1 to dichloro-
methane/MeOH 98/2, affording the final compound (yields
ranged from 43 to 78%).
The free base could be converted into its dihydrochloride salt
by dissolving the compound in dichloromethane and adding a
1M ethereal solution of HCl (2.1 equiv) dropwise. A yellow solid
precipitated and the suspension was stirred for 15 min. The
solvent was removed under reduced pressure affording a crude
material which was triturated with Et2O. The final compound
was then recovered by filtration (yield quantitative).
N-(1,1-Dimethylethyl)-N0-(3-{2-[4-(2-methyl-5-quinolinyl)-1-pi-
perazinyl]ethyl}phenyl)urea Dihydrochloride (28). The title com-
pound was prepared in 79% yield according to the general
procedure for the preparation of ureas (method C) starting from
intermediate 9 and 2-isocyanato-2-methylpropane. MS (ES/þ) m/
Methyl (3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}-
phenyl)carbamate (33). The title compound was prepared in
41% yield according to the general procedure for the prepara-
tion of carbamates (method D) starting from intermediate 9 and
methyl chloroformate. MS (ES) m/z: 405.4 [MH]þ. C24H28N4O2
1
z: 446 [MHþ] C27H35N5O requires 445. H NMR (400 MHz,
DMSO-d6) δ (ppm): 10.48 (bs, 1 H), 8.75 (bs, 1 H), 8.37 (s, 1H),
7.83 (bs, 2 H), 7.7 (bs, 1 H), 7.51 (s, 1 H), 7.38 (bs, 1 H), 7.17 (t,
1 H), 7.04 (dd, 1 H), 6.79 (d, 1 H), 6.08 (s, 1 H), 3.71-3.24 (bd, bt,
4 H), 3.6-3.3 (m, 4 H), 3.40 (m, 2 H), 3.02 (m, 2 H), 2.81 (bs, 3 H),
1.27 (s, 9 H).
N-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-
N0-phenylurea Dihydrochloride (29). The title compound was
prepared in 73% yield according to the general procedure for
the preparation of ureas (method C) starting from intermediate 9
and isocyanatobenzene. MS (ES/þ) m/z: 466 [MHþ] C29H31N5O
requires 465. 1H NMR (500 MHz, DMSO-d6) δ (ppm): 10.4 (bs,
1 H), 8.95 (bd, 2H), 8.75(bs, 1H), 7.83(bs, 2 H), 7.7(bs, 1 H), 7.54
(s, 1 H), 7.45 (dd, 2 H), 7.38 (bs, 1 H), 7.27 (m, 4 H), 6.96(m, 1 H),
6.91 (m, 1 H), 3.73 (bd, 2 H), 3.6-3.3(m, 6 H), 3.24 (t, 2 H), 3.08
(dd, 2 H), 2.81 (bs, 3 H).
N-(2-Fluorophenyl)-N0-(3-{2-[4-(2-methyl-5-quinolinyl)-1-piper-
azinyl]ethyl}phenyl)urea Dihydrochloride (30). The title compound
was prepared in 75% yield according to the general procedure for
the preparation of ureas (method C) starting from intermediate
9 and 1-fluoro-2-isocyanatobenzene. MS (ES/þ) m/z: 484 [MHþ]
C29H30FN5O requires 483. 1H NMR (400 MHz, DMSO-d6)
δ (ppm): 10. 9 (bs, 1 H), 9.36 (s, 1 H), 8.8 (bs, 1H), 8.67 (s, 1 H),
8.11 (t, 1 H), 7.86 (bs, 2H), 7.71 (bs, 1 H), 7.49 (d, 1 H), 7.37 (bs,
1
requires 404. H NMR (300 MHz, CDCl3) δ (ppm): 8.33 (d,
1 H), 7.70 (d, 1 H), 7.6 (t, 1 H), 7.30 (bs, 1 H), 7.25 (t, 1 H), 7.22
(dd, 1 H), 7.20 (d, 1 H), 7.10 (d, 1 H), 6.95 (dd, 1 H), 6.55 (bs,
1 H), 3.8 (s, 3 H), 3.28 (bm, 4 H), 3.28 (t, 2 H), 2.85 (t, 2 H), 2.75
(bm, 4 H), 2.66 (s, 3 H).
Ethyl (3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phe-
nyl)carbamate Fihydrochloride (34). The title compound was
prepared in 79% yield according to the general procedure for
the preparation of carbamates (method D) starting from inter-
mediate 9 and ethyl chloroformate. MS (ES) m/z: 419 [MHþ].
1
C25H30N4O2 requires 418. H NMR (400 MHz, DMSO-d6) δ
(ppm): 11.00 (bs, 1H), 9.74 (s, 1H), 8.95 (s, 1H), 8.00 (s, 2H), 7.87
(s, 1H), 7.57 (s, 1H), 7.51 (bs, 1H), 7.36 (m, 2H), 7.02 (d, 1H), 4.21
(q, 2H), 3.80 (d, 2H), 3.7-3.3 (m 8H), 3.17 (m, 2H), 2.96 (bs, 3H),
1.33 (t, 3H).
N-Methyl-N-(3-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]-
ethyl}phenyl) Acetamide (35). A solution of intermediate 12
(50 mg) was dissolved in THF (2.5 mL), and sodium hydride
(60% w/w oil dispersion, 0.005 g, 1 equiv) was added at 0 ꢀC. After
5 min, iodomethane was added (5 μL, 1.0 equiv), and the mixture
was warmed to room temperature. After 10 h, the solution was
partitioned between water (3 mL) and ethyl acetate (3 ꢀ 5 mL).

8238 Journal of Medicinal Chemistry, 2010, Vol. 53, No. 23
Leslie et al.
The combined organic extracts were washed with brine, dried
over sodium sulfate, and concentrated under vacuum. The crude
was purified by flash chromatography on silica gel, eluting with
a gradient from dichloromethane to dichloromethane-methanol
(98:2), affording the title compound in 61% yield (0.02 g). MS
1H), 8.84 (bm, 1H), 7.89 (bm, 2H), 7.76 (bm, 1H), 7.40 (m, 4H),
7.31 (s, 1H), 4.32 (t, 2H), 3.72-3.3 (m, 10H), 3.66 (t, 2H), 3.13 (m,
2H), 2.85 (bs, 3H), 2.10 (m, 2H).
1-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-
2,5-pyrrolidinedione (40). Dihydro-2,5-furandione (2 equiv) was
addedto a stirred solutionof intermediate(9) (1 equiv) in toluene/
pyridine (3:2) at room temperature under an inert atmosphere.
The solution was stirred for 30 min at room temperature and then
irradiated in a microwave reactor (PersonalChemistry Emrys
Optimiser, 300W, 170 ꢀC, 20 min, 4 cycles), diluted with dichlor-
omethane, and washed with a saturated aqueous solution of
NH4Cl and brine and then dried over Na2SO4. The solution
was concentrated under reduced pressure. Thecrude material was
purified on SPE cartridge (Silica) eluting with a gradient from
dichloromethane/MeOH 99/1 to dichloromethane/MeOH 98/2,
affording the final compound in 76% yield.
The free base was converted into its dihydrochloride salt by
dissolving the compound in Et2O and MeOH and adding an 1 M
ethereal solution of HCl (2.1 equiv) dropwise. A yellow solid
precipitated, and the suspension was stirred for 15 min. The solvent
was removed under reduced pressure, affording a crude material
which was triturated with Et2O to give the title compound. MS (ES)
m/z: 429 [MHþ]. C26H28N4O2 requires 428. 1H NMR (400 MHz,
DMSO-d6) δ (ppm): 11.1 (bs, 1H), 8.91 (bs, 1H), 7.94 (bs, 2H), 7.81
(bs, 1H), 7.49 (t, 1H), 7.44 (bs, 1H), 7.37 (d, 1H), 7.22 (s, 1H), 7.18
(d, 1H), 3.73 (bm, 2H), 3.59 (bm, 2H), 3.48 (bm, 4H), 3.33 (m, 2H),
3.19 (m, 2H), 2.89 (bs, 3H), 2.80 (bs, 4H).
[3-(1H-Pyrazol-1-yl)phenyl]acetic acid used in the synthesis
of 2-methyl-5-(4-{[3-(1H-pyrazol-1-yl)phenyl]acetyl}-1-pipera-
zinyl)quinoline was prepared as follows: Pyrazole (1.2 equiv),
Cs2CO3 (2.5 equiv), CuI (0.5 equiv), trans-1,2-cyclohexanedia-
mine (0.6 equiv), and dodecane (1 equiv) were added to a stirred
solution of 3-bromophenylacetic acid (1 equiv) in dioxane at
room temperature under an inert atmosphere. The mixture was
irradiated in a microwave reactor (PersonalChemistry Emrys
Optimiser, 300 W, 160 ꢀC, 20 min) and then added to a 1N
aqueous solution of NaOH and extracted with Et2O. The
aqueous phase was acidified to pH = 3 with 2N HCl solution
and then extracted with ethyl acetate; this phase was washed
with brine and then dried over Na2SO4, and the solvent was
removed under reduced pressure. The crude material was pur-
ified on SPE cartridge (Silica) eluting with a gradient from
cyclohexane/ethyl acetate 8:2, to cyclohexane/ethyl acetate
1:1, affording the title compound in 65% yield. MS (ES) m/z:
203 [MHþ]. C11H10N2O2 requires 202. 1H NMR (300 MHz,
CDCl3) δ (ppm): 7.9 (m, 1H), 7.75 (m, 1H), 7.65 (m, 1H), 7.55 (d,
1H), 7.35 (t, 1H), 7.3-7.1 (m, 2H), 6.55 (m, 1H), 3.7 (s, 2H)
2-Methyl-5-(4-{[3-(1H-pyrazol-1-yl)phenyl]acetyl}-1-piperazi-
nyl)quinoline used in the synthesis of intermediate 41 was pre-
1
(ES) m/z: 403.4 [MHþ]. C25H31ClNO4 requires 402. H NMR
(300 MHz, DMSO-d6) δ (ppm): 10.85 (bs, 1H), 8.79 (bs, 1H),
8-7 (bm, 16H), 3.8-3.0 (bm, 15H), 2.84 (bs, 3H), 1.79 (bs, 3H).
General Procedure for the Synthesis of Cyclic Ureas and Carba-
mates and Their Corresponding Dihydrochloride Salts Starting from
Intermediate 9. Method E. Diisopropylethylamine (1.5 equiv) and
a chloroformate or isocyanate (1.2eq) were added sequentially to
a stirred solution of intermediate 9 (1 equiv) in dichloromethane at
0 ꢀC. The solution was stirred for 1 h at room temperature and then
diluted with dichloromethane and washed with a saturated aqueous
solution of NH4Cl and brine and then dried over Na2SO4. The
solution was concentrated under reduced pressure. The crude
material was dissolved in dimethylformamide, cooled to 0 ꢀC,
and NaH (1.1 equiv) was added portionwise under an inert atmo-
sphere. The mixture was stirred for 2 h at room temperature, and
then the solvent was removed by means of an SCX cartridge. The
crude material was purified on SPE cartridge (Silica) eluting with
a gradient from dichloromethane/MeOH 99/1 to dichloromethane/
MeOH 98/2, affording the final compound (yields ranged from
22 to 87%).
The free base could be converted into its dihydrochloride salt
by dissolving the compound in Et2O and MeOH and adding an
1 M ethereal solution of HCl (2.1 equiv) dropwise. A yellow
solid precipitated, and the suspension was stirred for 15 min.
The solvent was removed under reduced pressure, affording a
crude material which was triturated with Et2O. The final
compound was then recovered by filtration (yield quantitative).
1-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-2-
imidazolidinone Dihydrochloride (36). The title compound was
prepared in 22% yield according to the general procedure for the
synthesis of cyclic ureas and carbamates (method E) starting from
intermediate 9 and 1-chloro-2-isocyanatoethane. MS (ES) m/z:
416 [MHþ]. C25H29N5O requires 415. 1H NMR (400 MHz,
DMSO-d6) δ (ppm): 10.60 (bs, 1H), 8.77 (s, 1H), 7.85 (s, 2H),
7.71 (s, 1H), 7.59 (s, 1H), 7.38 (dd, 1H), 7.28 (t, 1H), 6.96 (bs, 1H),
6.92 (d, 1H), 3.83 (m, 2H), 3.71 (d, 2H), 3.7-3.2 (m, 10H), 3.08 (m,
2H), 2.82 (bs, 3H).
1-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-
tetrahydro-2(1H)-pyrimidinone Dihydrochloride (37). The title
compound was prepared in 87% yield according to the general
procedure for the synthesis of cyclic ureas and carbamates
(method E) starting from intermediate 9 and 1-chloro-3-isocya-
natopropane. MS (ES) m/z: 430 [MHþ]. C26H31N5O requires
1
429. H NMR (400 MHz, DMSO-d6) δ (ppm): 11.05 (bs, 1H),
pared as follows: EDC HCl (1.5 equiv), HOBt (2 equiv), and
3
8.94 (s, 1H), 7.97 (s, 2H), 7.84 (d, 1H), 7.46 (bs, 1H), 7.30 (m, 2H),
7.19 (dd, 1H), 7.08 (d, 1H), 6.58 (s, 1H), 3.70 (bm, 4H), 3.63 (t,
2H), 3.6-3.3 (bm, 6H), 3.24 (t, 2H), 3.12 (m, 2H), 2.91 (s, 3H),
1.95 (t, 2H).
intermediate 7 (1 equiv) were added sequentially to a stirred
solution of [3-(1H-pyrazol-1-yl)phenyl]acetic acid (1.1 equiv) in
dimethylformamide at room temperature under an inert atmo-
sphere. The solvent was removed by means of an SCX cartridge.
The crude material was purified on SPE cartridge (Silica) eluting
with a gradient from dichloromethane/MeOH 99/1 to dichloro-
methane/MeOH 98/2, affording the title compound in 74%
3-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-
1,3-oxazolidin-2-one Dihydrochloride (38). The title compound
was prepared in 81% yield according to the general procedure for
the synthesis of cyclic ureas and carbamates (method E) starting
from intermediate 9 and (2-bromoethyl)carbamic chloride. MS
(ES) m/z: 417 [MHþ]. C25H28N4O2 requires 416. 1H NMR (400
MHz, DMSO-d6) δ (ppm): 10.99 (bs, 1H), 8.87 (bm, 1H), 7.91
(bm, 2H), 7.79 (bm, 1H), 7.57 (s, 1H), 7.40 (m, 3H), 7.08 (d, 1H),
4.43 (t, 2H), 4.07 (t, 2H), 3.72-3.3 (m, 10H), 3.15 (m, 2H), 2.87
(bs, 3H).
3-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-
tetrahydro-2H-1,3-oxazin-2-one Dihydrochloride (39). The title
compound was prepared in 75% yield according to the general
procedure for the synthesis of cyclic ureas and carbamates
(method E) starting from intermediate 9 and (3-chloropro-
pyl)carbamic chloride. MS (ES) m/z: 431 [MHþ]. C26H30N4O2
requires 430. 1H NMR (400 MHz, DMSO-d6) δ (ppm): 10.89 (bs,
1
yield. MS (ES) m/z: 412 [MHþ]. C25H25N5O requires 411. H
NMR (400 MHz, CDCl3) δ (ppm): 8.36 (d, 1H), 7.93 (d, 1H),
7.75 (d, 1H), 7.71 (s, 1H), 7.69 (s, 1H), 7.58 (d, 1H), 7.55 (t, 1H),
7.42 (t, 1H), 7.25 (m, 2H), 7.00 (d, 1H), 6.46 (s, 1H), 3.87 (s, 2H),
4.0-3.7 (m, 4H), 3.1-2.9 (m, 4H), 2.72 (s, 3H).
2-Methyl-5-(4-{2-[3-(1H-pyrazol-1-yl)phenyl]ethyl}-1-pipera-
zinyl)quinoline (41). A 1 M tetrahydrofuran solution of borane-
tetrahydrofuran complex (3 equiv) was added to a stirred
solution of 2-methyl-5-(4-{[3-(1H-pyrazol-1-yl)phenyl]acetyl}-
1-piperazinyl)quinoline (1 equiv) in tetrahydrofuran at room
temperature under an inert atmosphere. The solution was heated
to 60 ꢀC for 3 h. An aqueous 3N solution of HCl was added, and the
solution was stirred at room temperature for 12 h. The solvent was

Article
Journal of Medicinal Chemistry, 2010, Vol. 53, No. 23 8239
removed under reduced pressure. The crude material was purified
by SCX cartridge, affording the title compound in 52% yield. MS
(ES) m/z:398 [MHþ]. C25H27N5 requires 397. 1H NMR(300 MHz,
CDCl3) δ (ppm): 8.35 (d, 1H), 7.90 (d, 1H), 7.70 (d, 1H), 7.70 (s,
1H), 7.65 (t, 1H), 7.60 (t, 1H), 7.50 (dd, 1H), 7.35 (t, 1H), 7.25 (d,
1H), 7.15 (d, 1H), 7.05 (d, 1H), 6.45 (t, 1H), 3.20 (m, 4H), 3.0-2.7
(m, 8), 2.70 (s, 3H).
Nelson, D. L.; Wainscott, D. B.; Ahmad, L. J.; Shaw, J.; Threlkeld, P. G.;
Wong, D. T. Advances toward new antidepressants beyond SSRIs:
1-aryloxy-3-piperidinylpropan-2-ols with dual 5-HT1A receptor antag-
onism/SSRI activities. Part 3. Bioorg. Med. Chem. Lett. 2003, 13,
3939–3942. (h) Takeuchi, K.; Kohn, T. J.; Honigschmidt, N. A.; Rocco,
V. P.; Spinazze, P. G.; Hemrick-Luecke, S. K.; Thompson, L. K.; Evans,
D. C.; Rasmussen, K.; Koger, D.; Lodge, D.; Martin, L. J.; Shaw, J.;
Threlkeld, P. G.; Wong, D. T. Advances toward new antidepressants
beyond SSRIs: 1-aryloxy-3-piperidinylpropan-2-ols with dual 5-HT1A
receptor antagonism/SSRI activities. Part 5. Bioorg. Med. Chem. Lett.
2006, 1, 2347–2351. (i) Rocco, V. P.; Spinazze, P. G.; Kohn, T. J.;
Honigschmidt, N. A.; Nelson, D. L.; Bradley Wainscott, D.; Ahmad,
L. J.; Shaw, J.; Threlkeld, P. G.; Wong, D. T.; Takeuchi, K. Advances
toward new antidepressants beyond SSRIs: 1-aryloxy-3-piperidinyl-
propan-2-ols with dual 5-HT1A receptor antagonism/SSRI activities.
Part 4. Bioorg. Med. Chem. Lett. 2004, 14, 2653–2656. (j) Atkinson,
P. J.; Bromidge, S. M.; Duxon, M. S.; Gaster, L. M.; Hadley, M. S.;
Hammond, B.; Johnson, C. N.; Middlemiss, D. N.; North, S. E.; Price,
G. W.; Rami, H. K.; Riley, G. J.; Scott, C. M.; Shaw, T. E.; Starr, K. R.;
Stemp, G.; Thewlis, K. M.; Thomas, D. R.; Thompson, M.; Vong,
A. K. K.; Watson, J. M. 3,4-Dihydro-2H-benzoxazinones are 5-HT1A
receptor antagonists with potent 5-HT reuptake inhibitory activity.
Bioorg. Med. Chem. Lett. 2005, 15, 737–741. (k) Lovell, P. J.; Blaney,
F. E.; Goodacre, C. J.; Scott, C. M.; Smith, P. W.; Starr, K. R.; Thewlis,
K. M.; Vong, A. K. K.; Ward, S. E.; Watson, J. M. 3,4-Dihydro-2H-
benzoxazinones as dual-acting 5-HT1A receptor antagonists and serotonin
reuptake inhibitors. Bioorg. Med. Chem. Lett. 2007, 17, 1033–1036.
(l) Moltzen, E. K.; Mikkelsen, I.; Bjornholm, B.; Brennum, L. T.; Hogg,
S.; Sanchez, C. In vitro profile of LU 36-274: a compound with
combined 5-HTT/5-HT1A activity and putative fast onset of antidepres-
sant action. Soc. Neurosci. Abstr. 2003, 29, 958.16. (m) Taber, M. T.;
Torrente, J. R.; Palmer, J.; Poss, M. A.; Tortolani, D. R.; Yevich, J. P.;
Stark, A. D.; Mattson, R. J. Pharmacological characterization of BMS-
296859, a novel serotonin reuptake inhibitor and serotonin 5-HT1A
receptor antagonist. Soc. Neurosci. Abstr. 2003, 29, 958.15.
Acknowledgment. We thank Dr. Carla Marchiorro and
members of the Analytical Chemistry Department, Verona,
for support in the analytical characterization of the com-
pounds described. WealsothankLaurie GordonandGraham
Riley of Molecular Discovery Research and Matthew Hill of
the Neurosciences CEDD, Harlow, for support in the in vitro
characterization of the compounds described.
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8240 Journal of Medicinal Chemistry, 2010, Vol. 53, No. 23
Leslie et al.
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