Synthesis and characterization of 1,3-dihydro-benzo[b][1,4]diazepin-2-one derivatives: Part 4. in vivo active potent and selective non-competitive metabotropic glutamate receptor 2/3 antagonists

Article abstract of DOI:10.1016/j.bmcl.2010.09.125

This study completes a series of papers devoted to the characterization of the non-competitive mGluR2/3 antagonist properties of 1,3-dihydro-benzo[b][1,4] diazepin-2-one derivatives with particular emphasis on derivatizations compatible with brain penetra

Full text of DOI:10.1016/j.bmcl.2010.09.125

Bioorganic & Medicinal Chemistry Letters 20 (2010) 6969–6974
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
Synthesis and characterization of 1,3-dihydro-benzo[b][1,4]diazepin-2-one
derivatives: Part 4. In vivo active potent and selective non-competitive
metabotropic glutamate receptor 2/3 antagonists
Thomas J. Woltering a, , Jürgen Wichmann a, Erwin Goetschi a, Frédéric Knoflach b, Theresa M. Ballard b,
⇑
Jörg Huwyler c,#, Silvia Gatti b
a Discovery Chemistry, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
b CNS Research Functional Neuroscience, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
c Research DMPK, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 30 July 2010
Revised 24 September 2010
Accepted 25 September 2010
Available online 21 October 2010
This study completes a series of papers devoted to the characterization of the non-competitive mGluR2/3
antagonist properties of 1,3-dihydro-benzo[b][1,4]diazepin-2-one derivatives with particular emphasis
on derivatizations compatible with brain penetration and in vivo activity. Especially the compounds
bearing a para-pyridine consistently showed in vivo activity in rat behavioral models after oral adminis-
tration, for example, blockade of the mGluR2/3 agonist LY354740-induced hypoactivity and improve-
ment of a working memory deficit induced either by LY354740 or scopolamine in the delayed match
to position task (DMTP). Moreover, combination studies with a cholinesterase inhibitor show apparent
synergistic effects on working memory impairment induced by scopolamine.
Keywords:
Metabotropic glutamate receptors
1,3-Dihydro-benzo[b][1,4]diazepin-2-one
mGluR2 antagonist
mGluR3 antagonist
LY354740
Ó 2010 Elsevier Ltd. All rights reserved.
In vivo activity
Rats
Cognition models
The eight subtypes of the metabotropic glutamate receptor
family are classified into three groups according to their sequence
homology, pharmacology and second messenger coupling.1 While
group I receptors (mGluR1 and 5) are positively coupled to phos-
pholipase C, group II (mGluR2 and 3) and group III (mGluR4, 6, 7
and 8) receptors are negatively coupled to the activity of adenyl cy-
clase(s). Selective ligands for the different mGluRs are currently in
development for different indications. The therapeutic potential of
mGluR2/3 antagonists as antidepressants and cognitive enhancers
has been related in particular to the neurogenetic properties of
these compounds, to the control on glutamatergic function in cor-
tical and hippocampal regions and to the modulation of cholinergic
and monoaminergic systems, respectively.2–4
and the lead optimization program to obtain compounds like 4.
They are orally active, brain penetrating and also exhibit in vivo
activity demonstrated by the dose-dependent blockade of the
LY354740-induced hypolocomotion in mice.5
This Letter summarizes the results obtained when replacing the
1-imidazolyl and 1,2,3-triazolyl moieties in the 30-position with
other heterocycles as well as further efforts to optimize physico-
chemical properties to obtain drug-like derivatives. The regioselec-
tive synthesis of unsymmetrically 7,8-substituted 1,3-dihydro-
benzo[b][1,4]diazepin-2-ones was readily achieved by simple con-
densation of mono Boc protected 1,2-phenylenediamines 5 and
tert-butyl b-ketoesters 6 in refluxing toluene leading to the inter-
mediate b-ketoamides and treatment with TFA effected deprotec-
tion as well as concomitant cyclization yielding the desired 1,3-
dihydro-benzo[b][1,4]diazepin-2-ones 7 (Scheme 1).6,7,12
As previously described the pharmacological properties of these
compounds were consistent with a mechanism of non-competitive
antagonism at both mGluR2 and mGluR35,6 demonstrated by par-
tial inhibition of the binding of the selective agonist [3H]-LY354740
to rat mGluR2, full blockade of the effect of LY354740, (1S,3R)-
We previously reported on the discovery of the random screen-
ing hit 1 (Fig. 1), its characterization as a non-competitive antago-
nist at both recombinant mGluR2/3 and native mGluR2 (reversal of
LY354740-mediated inhibition of fEPSPs in the rat dentate gyrus)
⇑
Corresponding author. Tel.: +41616880407; fax: +41616888714.
E-mail address: thomas.woltering@roche.com (T.J. Woltering).
Present address: Fachhochschule Nordwestschweiz Hochschule für Life Sciences,
#
ACPD and
L-glutamate in both GTPc35S and cAMP assays and con-
centration-dependent inhibition of the glutamate-induced GIRK
Gründenstrasse 40, CH-4132 Muttenz, Switzerland.
0960-894X/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmcl.2010.09.125

6970
T. J. Woltering et al. / Bioorg. Med. Chem. Lett. 20 (2010) 6969–6974
F
F
Ph
O
H
N
H
N
O
H
N
O
Me
O
H
N
N
N
N
HO
N
N
N
CN
N
N
N
1
2
3
4
IC50 = 34 nM
IC50 = 26 nM
IC50 = 16 nM
ED50 = 3.3 mg/kg p.o.
IC50 = 6.4 µM
Figure 1. Development of the random screening hit 1 into compounds, like, for example, 2, 3 and 4, with low nanomolar IC50 values in binding inhibition studies carried out
with the mGluR2/3 agonist [3H]-LY354740 in membranes expressing recombinant rat mGluR2. The last step represented by 4 led to in vivo activity in mice behavioral models
(ED50 blockade of LY354740-induced hypolocomotion).5
H
N
O
O
O
R8
R7
R8
R7
NH2
R3'
medium to high permeability in the parallel artificial membrane
permeability assay (PAMPA). Unfortunately the addition of small
alkyl substituents on the m-pyridine did not result in such pre-
ferred profile for compounds (7aa–ad), therefore making this sub-
series finally less attractive. Neither the incorporation of
hydroxylated residues (7g, 7r, 7u and 7ap) nor attachment of re-
motely (7u) or directly joined basic moieties (7w, 7x, 7af and
7ag) to the 5- or 6-membered heterocycles resulted in improved
compounds. In summary, we were only able to identify highly po-
tent moieties in combination with quite high lipophilicity. Never-
theless we could keep the ligand-lipophilicity efficiency LLE
(LLE = p(IC50) ꢁ clogP)9 of the also functionally most active com-
pounds almost constant (7i: LLE 2.87; 7am: LLE 2.67) (Table 1).
The antagonistic effect of potent group II mGluR antagonists
(representative compounds listed in Table 2) has been also charac-
terized on Glutamate-stimulated G protein-coupled inwardly rec-
tifying potassium channel (GIRK) currents for rat and human
mGluR2 and rat mGluR3, respectively. There is no clear discrimina-
tion capacity between mGlu2 and mGlu3 for any of the listed
antagonists. Interestingly 7am (RO4491533) exhibits a very slow
on-rate probably due to a very high affinity for the allosteric site
of the mGlu2 receptor (Fig. 2).
Despite their high lipophilicity but due to their good permeabil-
ity (BCS class II) the most interesting compounds 7i and 7am (7i:
c log P 5.53; 7am: c log P 6.03) were quite suitable for in vivo eval-
uation, since they revealed low clearance in rat liver microsomes
(7i: 0.8 mL/min/kg, MAB 98%; 7am: 4.7 mL/min/kg, MAB 88%).
The rat pharmacokinetic profile of 7am has been determined after
2.5 mg/kg iv administration (n = 2 rats) and showed a long termi-
nal half life (T1/2 12.8 1.2 h), high volume of distribution (Vss
5.8 0.2 L/kg) and low clearance (CL 5.7 0.4 mL/min/kg). The bio-
availability (F 52 15%) was acceptable after oral administration
(10 mg/kg po, n = 2 rats).10 The observed brain/plasma ratio was
1.4. The selectivity for mGluR2/3 of the series of compounds 7 ver-
sus other metabotropic and ionotropic Glutamate receptors (e.g.,
NMDAR, AMPAR and mGluR4/5/8) as well as the specificity versus
other receptors (e.g., GABARs, Adenosine A1R and Orphanin R) was
tested in vitro using recombinant systems and in all cases no effect
a, b
+
t-BuO
NHBoc
N
R3'
5
6
7
Scheme 1. Regioselective synthesis of unsymmetrically 7,8-substituted 1,3-dihy-
dro-benzo[b][1,4]diazepin-2-ones 7. Reagents and conditions: (a) toluene, reflux;
(b) TFA [optional anisole], DCM, rt.
currents. Table 1 contains IC50 values calculated for each com-
pound in affinity studies (partial displacement of 10 nM [3H]-
LY354740, recombinant rat mGluR2) and cell based assays: con-
centration-dependent antagonism of the effect of the mGluR2/3
agonist (1S,3R)-ACPD (10
in cells permanently expressing recombinant rat mGluR2 (cells
stimulated with Forskolin 10
M).5
lM-EC90) on intracellular cAMP levels
l
In our efforts to develop more drug-like mGluR2/3 antagonists
we sought to further reduce their lipophilicity (2: c log P 4.86; cal-
culated log(coctanol/cwater); 3: c log P 4.85; 4: c log P 4.82).8 With re-
gard to the left part of compounds 7 the best compromise between
lipophilicity and activity has been found by combination of a tri-
fluoromethyl group in 8-position and a simple methyl group in
7-position (Table 1). Our main focus in this study was the search
for the optimal heterocycle in the 30-position. While the 1-imidaz-
ole or the 1,2,3-triazole group produced highly potent compounds
(7a, 7b), they either suffered from strong cytochrome P450 3A4
isoenzyme inhibition (7a: IC50 <0.1 lM) or lack of in vivo activity
(7b). The in-depth evaluation of a series of five-membered hetero-
cycles (e.g., 7a–g) revealed that very potent compounds could be
obtained, but only at the expense of high lipophilicity, as shown
for the isoxazole 7c (c log P 5.00). The more polar isomeric 1,2,4-
triazole 7d (c log P 3.69) lost its activity in the cAMP assay, while
oxazole 7e and pyrazole 7f were overall far less potent.
Incorporation of six-membered heterocycles, especially the m-
and p-pyridine (7h, 7z) led also to very active compounds, whereas
o-pyridines (7y) as well as pyridazines (7ah, 7ai), pyrimidines (7aj,
7ak) or pyrazines (7al) were all less effective. In order to avoid the
drug–drug interaction (DDI) potential shielding of the p-pyridine
nitrogen by ortho-substitution was necessary to block its ability
could be demonstrated at a concentration <1 lM.
Compound 7am’s in vivo antagonistic properties after adminis-
tration per os by gavage in rats were shown (Fig. 3) to be consistent
with the in vivo exposure and the brain penetration data. The
mGluR2/3 agonist LY354740 produces a dose-dependent decrease
of horizontal activity after subcutaneous administration (10 mg/kg,
30 min prior to testing) in rats. The experimental conditions of this
test have been previously validated for the contribution of mGluR2
using mGluR2 null mutant mice.3,11 The po administration of 7am
180 min prior to the mGluR2/3 agonist (10 mg/kg s.c.) was able to
significantly block the hypoactivity caused by the administration
of LY354740. It should be noted that 7am did not cause a signifi-
cant increase in locomotor activity when administered alone. The
of binding to CYP450 3A4 isoenzyme (7h: IC50 ꢀ0.2
lM; 7z: IC50
1.8 M). Electron deficient substituents, like cyano or trifluoro-
l
methyl (7k, l), resulted in less active compounds. Most effectively
and without significant increase of lipophilicity proved to be a sim-
ple 2-methyl group or a 2,6-dimethyl substitution (CYP450 3A4
IC50 1.9 lM (7i), 4.8 lM (7am)). As a benefit the concomitant in-
crease of basicity (7h: pKa 5.4; 7i: pKa 5.9; 7am: pKa 6.2), enhanced
the solubility (thermodynamic solubility at pH 3: 7h ꢀ5 mg/L; 7i
45 mg/L; 7am 64 mg/L) and led to overall improvement of phys-
ico-chemical properties. It is noteworthy, that all relevant com-
pounds of this structural class, including 7i and 7am, showed

T. J. Woltering et al. / Bioorg. Med. Chem. Lett. 20 (2010) 6969–6974
6971
Table 1
Structure–activity relationship data related to the new 1,3-dihydro-benzo[b][1,4]diazepin-2-ones 7 described in this study
0
Compound R3
R8
R7
c log P Rat mGluR2 [3H]-
LY354740 bindinga inhibition of Forskolin
IC50 M)
stimulated cAMPb
Rat mGluR2 (1S,3R)-ACPD LLE = p(IC50 of [3H]-
LY354740
binding)—c log P
(
l
IC50
(lM)
1
2
CN
CN
Me
Ph-C„C–
H
H
3.29
4.86
6400
0.034
nt
ꢁ1.10
0.017
0.011
2.61
N
3
4-F–C6H4–C„C– HO
4.85
4.82
4.57
4.36
0.026
2.74
3.1
N
N
N
N
4
2-F–C6H4–
F3C–
H
0.012
0.012
0.009
0.027
0.019
0.039
N
7a
7b
Me
Me
3.35
3.69
N
N
N
N
F3C–
N
O
7c
7d
7e
F3C–
F3C–
F3C–
Me
Me
H
5
0.005
0.008
0.35
0.009
0.075
nt
3.3
N
N
N
3.69
4.19
4.41
2.27
O
N
N
N
7f
F3C–
F3C–
F3C–
H
4.36
3.33
5.03
0.039
0.12
0.19
nt
3.05
3.59
3.37
N
N
N
7g
7h
Me
OH
N
R=
H
Me
0.004
0.011
R
7i
7j
7k
7l
Me
Et
CN
CF3
F3C–
F3C–
F3C–
F3C–
F3C–
F3C–
F3C–
F3C–
F3C–
F3C–
F3C–
F3C–
F3C–
F3C–
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
5.53
6.06
4.85
6.05
5.97
6.46
7.09
7.13
7.1
4.44
4.83
4.7
4.86
5.84
5.86
5.04
0.004
0.008
0.012
0.066
0.01
0.004
0.005
0.018
nt
0.006
0.01
0.007
nt
0.005
0.018
0.006
0.014
nt
2.87
2.04
3.07
1.13
2.03
1.94
0.91
ꢁ0.20
0.7
7m
7n
7o
7p
7q
7r
7s
7t
7u
7v
7w
7x
c-Propyl
i-Propyl
c-Pentyl
Ph
CH2Ph
CH2OH
CH2OMe
CMe2OH
CH2NMe2
OMe
0.004
0.01
0.118
0.016
0.013
0.013
0.04
0.274
0.013
0.059
0.029
3.45
3.06
2.7
1.7
0.016
nt
nt
2.05
1.37
2.5
1-Pyrrolidinyl F3C–
4-Morpholinyl F3C–
7y
F3C–
Me
5.24
0.026
0.03
2.35
N
R
7z
R=
H
F3C–
Me
5.03
0.002
0.003
3.67
N
7aa
7ab
7ac
7ad
7ae
7af
Me
Et
c-Propyl
i-Propyl
OMe
NH2
F3C–
F3C–
F3C–
F3C–
F3C–
F3C–
F3C–
Me
Me
Me
Me
Me
Me
Me
5.53
6.06
5.97
6.46
5.84
4.71
5.74
0.013
0.009
0.006
0.01
0.005
0.014
0.086
0.005
0.018
0.02
0.01
0.01
0.16
nt
2.36
1.99
2.25
1.54
2.46
3.14
1.33
7ag
NMe2
N
N
7ah
7ai
7aj
F3C–
F3C–
F3C–
Me
Me
Me
3.82
4.03
4.27
0.018
0.128
0.006
0.072
nt
3.92
2.86
N
N
N
N
0.05
3.95
(continued on next page)

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T. J. Woltering et al. / Bioorg. Med. Chem. Lett. 20 (2010) 6969–6974
Table 1 (continued)
0
Compound R3
R8
R7
c log P Rat mGluR2 [3H]-
LY354740 bindinga inhibition of Forskolin
IC50 M)
stimulated cAMPb
Rat mGluR2 (1S,3R)-ACPD LLE = p(IC50 of [3H]-
LY354740
binding)—c log P
(
l
IC50
(lM)
N
7ak
7al
F3C–
F3C–
Me
Me
4.06
4.27
0.023
0.02
0.048
0.016
3.58
3.43
N
N
N
Me
N
7am
R=
Me
F3C–
Me
6.03
0.002
0.003
2.67
R
7an
7ao
7ap
7aq
Et
F3C–
F3C–
F3C–
F3C–
Me
Me
Me
Me
6.56
6.47
4.94
5.33
0.002
0.002
0.014
0.008
0.004
0.004
0.015
0.005
2.14
2.23
2.91
2.77
c-Propyl
CH2OH
CH2OMe
N
N
7ar
7as
F3C–
F3C– 6.57
0.007
0.007
0.026
1.58
R=
H
F3C–
H
4.53
0.01
3.47
R
7at
H
H
Me
Me
Me
F3C–
Cl
Cl
F3C–
F3C–
OEt
H
Cl
H
OEt
5.11
4.17
5.35
5.03
5.61
0.004
0.008
0.004
0.018
0.006
0.01
3.29
3.93
3.05
2.71
2.61
7au
7av
7aw
7ax
0.003
0.002
0.036
0.008
R
3’, R7 and R8 refer to the positions of R’s in Scheme 1.
nt, not tested.
a
Values are means of at least two independent experiments.
Values are means of three independent experiments.
b
Table 2
0
-200
-400
-600
-800
IC50 values for GIRK current inhibition by selected compounds in CHO cells expressing
mGluR2 and mGluR3 receptors
Compound Rat mGluR2 GIRK
Rat mGluR3 GIRK
inhibition IC50
Human mGluR2
GIRK inhibition IC50
(lM)
a
a
a
inhibition IC50
(l
M)
(l
M)
3
4
7i
7am
7as
7at
7au
7av
7aw
7ax
0.024
0.011
0.013
<0.01
0.101
0.008
nt
nt
nt
nt
nt
nt
nt
0.033
0.014
<0.01
0.029
0.006
nt
0.030
0.017
0.003
0.041
0.014
0.052
0.038
0.010
0.007
0.025
0.015
-1000
0
120
240
360
480
600
720
840
Time [sec]
a
Values are means of 3–5 independent experiments, (nt = not tested).
Figure 2a. Time course of 7am-induced inhibition of GIRK currents in
a cell
expressing rat mGluR2. Glutamate (1 M) was applied in the presence of 10 nM
l
7am. The compound showed very slow on-rate kinetics. The block was almost
complete but only after 15 min application.
in vivo data related to 7am have been presented in poster format
by Knoflach et al.4c and in patents;12 a successive poster publica-
tion from Campo et al.4d is also referring to the same compound
7am (RO4491533).
the impairing effects of ketamine in the continuous performance
test in healthy human volunteers.13 The direct translation of these
effects from rodents to humans is still under discussion.14
The mGluR2/3 agonist LY354740 produces a dose-dependent
impairment of working memory in the delayed match to position
(DMTP) task in rats, but does not have an effect on parameters of
task performance such as missed trials and latencies to respond.3
Compound 7am dose-dependently reversed the mGluR2/3 ago-
nist-induced impairment of working memory, with partial reversal
at 3 mg/kg po and full reversal at 10 mg/kg po (Fig. 4a, % total cor-
rect choices). It has been shown in both rats and monkeys that
LY354740 impairs working memory, however, in humans there
are no reports to date that mGluR2/3 agonists impair cognition.
Moreover, it has been shown that LY354740 has a trend to reduce
However, we have also shown that compound 7am partially but
significantly reversed a scopolamine-induced working memory
impairment in the DMTP task at 3 mg/kg po (Fig. 4b). Interestingly
when sub-threshold doses of 7am and donepezil (AriceptÒ) were
co-administered they showed an apparent synergistic effect versus
the scopolamine-induced working memory deficit in the DMTP
task in rats (Fig. 4c and d).11,12b Interestingly, compound 7am also
exhibits mild antidepressant-like activity in the mouse forced
swim test after oral administration in a consistent range of doses.4d

T. J. Woltering et al. / Bioorg. Med. Chem. Lett. 20 (2010) 6969–6974
6973
5000
4000
3000
2000
2000
1500
1000
500
0
0
-200
-400
-600
-800
-1000
##
*
##
*
**
***
1000
0
veh
veh
7am (1)
7am (3)
+ LY354740 (10 mg/kg s.c.)
7am (10)
vehicle
0
20000
40000
Figure 3. Spontaneous locomotor activity in rats (total horizontal activity counts in
30 min): reversal of LY354740-induced (10 mg/kg s.c., ptt 30 min) hypoactivity by
pretreatment with compound 7am. Dose response assessment of 7am suspension
prepared in 0.3% Tween 80 v/v saline (at 1, 3 and 10 mg/kg po, ptt 180 min). (n = 8
rats/group; statistics: p <0.01; *p <0.05, ***p <0.001 vs veh. + veh.; ##p <0.01 vs
veh. + LY354740). Plasma (h) and brain (s) levels for 7am (approx. 210 min post
administration) are also reported. Brain/plasma ratio remains constant (B/P ꢀ1.4) at
all doses.
Time [ms]
Figure 2b. Superimposed glutamate-induced currents in the absence and presence
of 7am, recorded at 90 s intervals in a representative human mGluR2 expressing
cell. The gray current trace is a control response to 1 lM L-glutamate, the black
currents were recorded in the presence of 10 nM 7am.
b
a
100
100
##
###
90
80
70
60
50
90
80
70
60
50
###
###
###
###
***
***
**
##
***
***
***
***
0
8
16
24
0
8
16
24
Delays [s]
Delays [s]
d
c
100
90
80
70
60
50
40
100
##
##
90
80
70
60
50
**
##
*
**
**
##
**
**
**
**
7am
7am
V/V
/V V/V
/V V/D 7am
/D
0
8
16
24
+ V
+ SCOPOLAMINE
Delays [s]
Figure 4. (a) Effect of 7am (1, 3, 10 mg/kg po, ptt 180 min) versus mGluR2/3 agonist (LY354740: 6 mg/kg ip)-induced working memory impairment in the delayed match to
position (DMTP) task in rats. (b). Effect of 7am (1, 3, 10 mg/kg po, ptt 180 min) versus scopolamine (0.06 mg/kg s.c.)-induced working memory impairment in the DMTP task
in rats. (c) Combination of sub-threshold doses of 7am (1 mg/kg po) and donepezil (1 mg/kg po) significantly reversed the scopolamine (0.06 mg/kg s.c.)-induced working
memory impairment in the DMTP task. Data are presented as mean correct responses SEM. Percent correct responses across delay intervals: (a) vehicle (s); LY354740 (d);
7am at (1 mg/kg po) (4), (3 mg/kg po) (e) and (10 mg/kg po) (h) versus LY354740 (n = 12 rats); (b) vehicle (s); scopolamine (d); 7am at (1 mg/kg po) (4), (3 mg/kg po) (e)
and (10 mg/kg po) (h) versus scopolamine (n = 12 rats). (c) Vehicle (s); scopolamine (0.06 mg/kg s.c.) (d); 7am (1 mg/kg po, ptt 180 min) versus scopolamine (0.06 mg/kg
s.c.) (ꢀ); donepezil (1 mg/kg po, ptt 35 min) versus scopolamine (0.06 mg/kg s.c.) (j); 7am (1 mg/kg po, ptt 180 min) plus donepezil (1 mg/kg po, ptt 35 min) versus
scopolamine (0.06 mg/kg s.c.) (N) (n = 12 rats). (d). Total percent correct responses collapsed across delays: V: vehicle; D: donepezil (1 mg/kg po, ptt 35 min); 7am (1 mg/kg
po, ptt 180 min); scopolamine (0.06 mg/kg s.c.) (n = 12 rats). Statistics: *p <0.05, **p <0.01, ***p <0.001 versus vehicle-treated group; ##p <0.01, ###p <0.001 versus LY354740
or scopolamine-treated group).

6974
T. J. Woltering et al. / Bioorg. Med. Chem. Lett. 20 (2010) 6969–6974
Metabotropic Glutamate Receptors, Taormina, Sicily, Italy, September, 2005;
In addition, the in vivo active compounds described in this Let-
poster 15.; (d) Campo, B.; Girard, F.; Kalinichev, M.; Celanire, S.; Legrand, C.;
Rizzo, O.; Bessif, A.; Royer-Urios, I.; Lutjens, R.; Poli, S.; Le Poul, E. Abstract of
Papers, 39th Annual Meeting of the Society for Neuroscience, Chicago, IL;
Society for Neuroscience: Washington, DC, 2009; Abstract 343.8/Q11.; (e)
Girard, F.; Campo, B.; Kalinichev, M.; Celanire, S.; Lasserre, S.; Rizzo, O.; Bessif,
A.; Royer-Urios, I.; Poli, S.; Le Poul, E. Abstract of Papers, 39th Annual Meeting of
the Society for Neuroscience, Chicago, IL; Society for Neuroscience:
Washington, DC, 2009; Abstract 844.3/O36.
ter are in general well tolerated and they do not cause behavioral
disruption up to 30 mg/kg po in neurological assessment including
rotarod and grip strength and on spontaneous locomotor activity.
In summary, with the unique combination of trifluoromethyl in
8-position and methyl in 7-position and the incorporation of a 2-
methyl- or 2,6-dimethyl-substituted para-pyridine in the 30-posi-
tion we were able to develop a series of in vivo active 1,3-dihy-
dro-benzo[b][1,4]diazepin-2-one derivatives with drug potential.
This is shown by the capacity of these compounds to rescue the
working memory impairment induced by either an mGluR2/3 ago-
nist or a muscarinic antagonist in the DMTP task in rats. A more de-
tailed description of the pharmacology of compounds 7am and 7i
and their capacity to act as cognitive enhancers in animal models
of aging and Alzheimer’s disease will follow in due course.
5. (a) Woltering, T. J.; Adam, G.; Alanine, A.; Wichmann, J.; Knoflach, F.; Mutel, V.;
Gatti, S. Bioorg. Med. Chem. Lett. 2007, 17, 6811; (b) Woltering, T. J.; Adam, G.;
Wichmann, J.; Goetschi, E.; Kew, J. N. C.; Knoflach, F.; Mutel, V.; Gatti, S. Bioorg.
Med. Chem. Lett. 2008, 18, 1091; (c) Woltering, T. J.; Wichmann, J.; Goetschi, E.;
Adam, G.; Kew, J. N. C.; Knoflach, F.; Ballard, T. M.; Huwyler, J.; Mutel, V.; Gatti,
S. Bioorg. Med. Chem. Lett. 2008, 18, 2725.
6. Hemstapat, K.; Da Costa, H.; Nong, Y.; Brady, A. E.; Luo, Q.; Niswender, C. M.;
Tamagnan, G. D.; Conn, P. J. J. Pharmacol. Exp. Ther. 2007, 322, 254.
7. (a) Adam, G.; Alanine, A.; Goetschi, E.; Mutel, V. J.; Woltering, T. J. World Patent
WO01/29011, 2001; Chem. Abstr. 2001, 134, 311234.; (b) Adam, G.; Alanine, A.;
Goetschi, E.; Mutel, V. J.; Woltering, T. J. World Patent WO01/29012, 2001;
Chem. Abstr. 2001, 134, 311235.; (c) Adam, G.; Goetschi, E.; Mutel, V.;
Wichmann, J.; Woltering T. J. World Patent WO02/083652, 2002; Chem. Abstr.
2002, 137, 325447.; (d) Adam, G.; Goetschi, E.; Mutel, V.; Wichmann, J.;
Woltering T. J. World Patent WO02/083665, 2002; Chem. Abstr. 2002, 137,
325438.
8. Due to constant improvements of Roche internal in silico tools for c log P
prediction, the new values may differ from previously reported ones.
9. Leeson, P. D.; Springthorpe, B. Nat. Rev. Drug Disc. 2007, 6, 881.
10. The experimental procedures used in the present investigation received prior
approval from the City of Basel Cantonal Animal Protection Committee based
on adherence to federal and local regulations.
11. (a) Spooren, W.; Gasparini, F.; van der Putten, H.; Koller, M. I. S.; Nakanishi, S.;
Kuhn, R. Eur. J. Pharmacol. 2000, 397, R1; (b) Ballard, T. M.; Kew, J. N. C.;
Richards, J. G.; Woltering, T. J.; Adam, G.; Nakanishi, S.; Kemp, J. A.; Mutel, V.;
Higgins, G. A. Abstract of Papers, 31st Annual Meeting of the Society for
Neuroscience, San Diego, CA; Society for Neuroscience: Washington, DC, 2001;
Abstract 705.11.
Acknowledgments
We cordially thank G. Achermann, J. Beck, N. Benedetti, D. Bu-
chy, S. Chaboz, M. Dellenbach, M. Enderlin, N. Grossmann, R. Haab,
A. Maier, A. Nilly, P. Oberli, M.-C. Pflimlin, P. Reindl , H. Schär, M.
Weber and R. Wyler for their skilful technical assistance.
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