Advances in tetrahydropyrido[1,2-a]isoindolone (valmerins) series: Potent glycogen synthase kinase 3 and cyclin dependent kinase 5 inhibitors

Article abstract of DOI:10.1016/j.ejmech.2015.06.046

Abstract An efficient synthetic strategy was developed to modulate the structure of the tetrahydropyridine isoindolone (Valmerin) skeleton. A library of more than 30 novel final structures was generated. Biological activities on CDK5 and GSK3 as well as cellular effects on cancer cell lines were measured for each novel compound. Additionally docking studies were performed to support medicinal chemistry efforts. A strong GSK3/CDK5 dual inhibitor (38, IC₅₀ GSK3/CDK5 32/84 nM) was obtained. A set of highly selective GSK3 inhibitors was synthesized by fine-tuning structural modifications (29 IC₅₀ GSK3/CDK5 32/320 nM). Antiproliferative effects on cells were correlated with the in vitro kinase activities and the best effects were obtained with lung and colon cell lines.

Full text of DOI:10.1016/j.ejmech.2015.06.046

European Journal of Medicinal Chemistry 101 (2015) 274e287
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Research paper
Advances in tetrahydropyrido[1,2-a]isoindolone (valmerins) series:
Potent glycogen synthase kinase 3 and cyclin dependent kinase 5
inhibitors
a
a
a
a
b
Raj a^ a Boulahjar , Aziz Ouach , St eꢀ phane Bourg , Pascal Bonnet , Olivier Lozach ,
b
c
c
d
Laurent Meijer , Christiane Guguen-Guillouzo , R eꢀ my Le Guevel , Saïd Lazar ,
d
e
a,
**
, Sylvain Routier a
, *
Mohamed Akssira , Yves Troin , G eꢀ rald Guillaumet
a
Univ Orleans, CNRS UMR 7311, Institut de Chimie Organique et Analytique, rue de Chartres, BP 6759, 45067 Orl ꢀe ans Cedex 2, France
C.N.R.S., ‘Protein Phosphorylation & Human Disease’ Group, USR3151, Station Biologique, BP 74, 29682 Roscoff Cedex, France
Plateforme ImPACcell-SFR BIOSIT UMS-CNRS3480 UMS-INSERM018, Universit ꢀe de Rennes1, 35043 Rennes Cedex, France
b
c
d
Laboratoire de Chimie, Bioorganique et Analytique, URAC 22 p o^ le R ꢀe pam, Universit ꢀe Hassan II Mohammedia-Casablanca, BP 146, 28800 Mohammedia,
Morocco
e
Clermont Universit ꢀe , ENSCCF, Laboratoire de Chimie des H ꢀe t ꢀe rocycles et des Glucides, BP 10448, 63000 Clermont-Ferrand, France
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 21 April 2015
Received in revised form
An efficient synthetic strategy was developed to modulate the structure of the tetrahydropyridine iso-
indolone (Valmerin) skeleton. A library of more than 30 novel final structures was generated. Biological
activities on CDK5 and GSK3 as well as cellular effects on cancer cell lines were measured for each novel
compound. Additionally docking studies were performed to support medicinal chemistry efforts. A
strong GSK3/CDK5 dual inhibitor (38, IC50 GSK3/CDK5 32/84 nM) was obtained. A set of highly selective
GSK3 inhibitors was synthesized by fine-tuning structural modifications (29 IC50 GSK3/CDK5 32/
10 June 2015
Accepted 22 June 2015
Available online 27 June 2015
3
20 nM). Antiproliferative effects on cells were correlated with the in vitro kinase activities and the best
Keywords:
Pyridoisoindolone
Valmerin
effects were obtained with lung and colon cell lines.
©
2015 Elsevier Masson SAS. All rights reserved.
GSK3
CDK5
Kinase research
In vitro assays
1
. Introduction
phosphorylation events. Among the 518 kinases identified to date,
it has been established that the ubiquitously expressed glycogen
synthase kinase-3 (GSK3), mainly present in the cytoplasm, and
cyclin-depend kinase 5 (CDK5), a nuclear pivot for cell cycle pro-
gression, play important roles in several biological mechanisms.
GSK3 and CDK5 are reported as key mediators in neuronal migra-
tion, embryonic development, protein synthesis, cell proliferation
and differentiation, microtubule dynamics, cell motility, steroido-
genesis and apoptosis [2]. Deregulation of these protein kinases has
been found in many human diseases and small molecules kinase
inhibitor, which efficiently target GSK3 and CDK5 enzymes, are
considered as potential solutions to contain the evolution of cancer.
Several drugs acting on these two biological targets have entered
clinical trials such as roscovitine (Seliciclib) that has progressed to
phase II (Fig. 1) [6,7].
Cancer results mainly from cell cycle perturbations and leads to
anarchic cellular proliferation. Gene mutations associated with
cancer disease induce abnormality in cellular proliferation and
differentiation and are often linked to resistance of several thera-
pies s [1e5]. The four phases (G1, S, G2, M) are critical for the
regulation of the cell cycle and a number of biochemical pathways
have been discovered as key mechanisms for the initiation of a
particular cell cycle event. Many protein kinases are activated in
these biochemical pathways and mediate biological information
in downstream signalling pathways through controlled
*
Corresponding author.
*
* Corresponding author.
E-mail addresses: gerald.guillaumet@univ-orleans.fr (G. Guillaumet), sylvain.
As part of our efforts in finding better therapeutic solutions, our
team has been involved for several years in the synthesis of novel
routier@univ-orleans.fr (S. Routier).
http://dx.doi.org/10.1016/j.ejmech.2015.06.046
0223-5234/© 2015 Elsevier Masson SAS. All rights reserved.

R. Boulahjar et al. / European Journal of Medicinal Chemistry 101 (2015) 274e287
275
Fig. 1. Some examples of CDK5, GSK3 and DYRK1A inhibitors.
disease-relevant kinase inhibitors and in particular drugs acting on
CDK5, GSK3 and dual-specificity tyrosine phosphorylation-
regulated kinase 1A (DYRK1A). We have developed synthetic stra-
tegies to optimize lamellarin-like or V-shaped indolylazines de-
rivatives as well as oxo-arcyriaflavin or indolocarbazole analogues
pathways. These tools will lead to a good understanding of the
action mode and will offer to medicinal chemists solutions to
prepare, as example, roscovitine successors. Finally, we aim to
answer the following question: Is the valmerin heterocyclic scaffold
a promising pharmacophoric model able to modulate kinase ac-
tivity with achievable cellular effects?
(Fig. 1), each series providing original skeletons as well as potent
ATP competitive inhibitors able to inhibit the previously mentioned
protein kinases [8].
To access the valmerin core, we modified the synthetic pathway
and optimized novel synthetic routes. The nature and size of the
urea heterocyclic group as well as the substitution of the tetrahy-
dropyridine ring were the two main objectives of the chemistry
efforts. The novel library was used to assess novel structure activity
relationships. Molecular modelling studies were performed to
corroborate the in vitro kinase activities with structural modifica-
tions. Finally, cellular effects were measured on several tumour cell
lines in this study.
In addition, we have also performed virtual screening cam-
paigns on CDK5, GSK3 and DYRK1A to rationalize the structur-
eeactivity relationships (SAR) and to accelerate optimization
processes. During our investigations in the proposed tetrahy-
dropyridoisoindolone series, we first identified valmerin 1 (Scheme
1
) and evaluated its biological effects. This series exhibits strong
kinase inhibition, induces apoptosis in cancer cells and shows
in vivo tumour regression. We showed that the lead compound 1
acts on CDK1 or CDK5 and GSK3 in the nanomolar range without
2. Chemistry
any effect on DYRK1A (up to 10
and GSK3.
mM), the upstream regulator of CDK
The synthesis of valmerins was achieved from 2-
The development of the valmerin series, acting on GSK3 and/or
CDK5, required a thorough exploration of each scaffold substituent
to identify the critical pharmacophore. In a previous report, we
determined that the tetrahydropyridoisoindolone core linked to a
nitrophtalimide 2 and led to the interesting nitro derivatives 3
and 4 having a protected, but not necessary, ketone on the tetra-
hydropyridine core [9]. The transformation of dioxolane to thio-
3 2 2 2
acetal using ethanedithiol in the presence of BF $Et O in CH Cl
(
het)Ar urea can induce kinase inhibition [9] and no modification to
was first performed from 3 [10]. Compound 5 was isolated with a
yield of 86%. Ketone 4 was then subjected to a reduction using
sodium borohydride in a mixture of THF/MeOH in an 86% yield. The
separation of the two stereoisomers cis and trans of 4 appears as
very critical. HPLC purification indicates the presence of a mixture
of the two diastereoisomers in a 7:3 ratio in favour of the cis
configuration [11]. The purification led to an analytical amount of
pure diastereoisomer 6 in the very low yield of 14%. The next
methylation step was therefore carried out on the crude cis þ trans
mixture which was isolated directly after reduction of the ketone.
the tetrahydropyridine ring was explored. We surmise that such
modification would interfere at the ATP binding site in the recog-
nition mechanism between the novel molecules and the enzyme
and would globally enhance the binding affinities and block kinase
catalytic function. Specifically, we hypothesize that the structural
modulation will lead to valmerins having an activity on GSK3 and
selective to CDK5 or active on both GSK3 and CDK5. Having in hand
such molecules in a single chemical family will be useful to un-
derstand the implication of Valmerins in the CDK and GSK3 cell
Scheme 1. Retrosynthetic scheme for the design of novel CDK5, GSK3 and DYRK1A valmerin inhibitors.

276
R. Boulahjar et al. / European Journal of Medicinal Chemistry 101 (2015) 274e287
Fortunately only the cis regioisomer 6 reacted under the special
3. Kinase assays
conditions involving methyl iodide in the presence of Ag
2
O in THF
ꢀ
at 50 C in a satisfying yield (other Williamson type conditions
failed) [12]. Derivative 7 was also purified satisfyingly as a single cis
diastereoisomer (COSY, NOESY and HSQC NMR experiments) with a
yield, calculated from 4, of 61%. Reduction of the nitro groups of 5
The library of valmerins 11e41 was first evaluated in a primary
kinase screen using the targeted enzymes CDK5 and GSK3 and the
off-target kinase DYRK1A (Table 2). In a previous study, we clearly
showed that the urea moiety is necessary to induce a biological
effect [9]. More specifically, close to the tetrahydropyr-
idoisoindolone scaffold, a heteroaryl urea is necessary in position C-
2
and 3 were carried out using an excess of SnCl and gave amino
compounds 8 and 10 in a very good yield but, starting from 7, the
reaction failed. When the reduction of derivative 7 was carried out
under a hydrogen atmosphere, compound 9 was generated in a 95%
yield (Scheme 2).
0
10. The heterocycles contain a nitrogen atom in position C-2 . Val-
merin 1 acts on CDK5 and GSK3 in a quite similar manner.
In our novel valmerins (Table 2), whatever the group used in
position C-2, a urea in C-10 with a small five-membered cycle such
as pyrazole (entry 6) led to the loss of kinase inhibition whereas an
increase in the (het)Ar size such as a quinoline moiety (entry 4) led
to some active compounds. Derivatives 40 and 22 act mainly on
GSK3 (35 and 180 nM respectively; entries 4e, 4c). Valmerin 40
which possesses a C-2 hydroxyl group is one of the most selective
derivatives so far, as it interferes with CDK5 and DYRK1A in a
micromolar range. The first discrimination of CDK5 and GSK3 is
achieved in this example.
We found CDK5 inhibitors with remarkable IC50 in the nano-
molar range without effect on GSK3 but modifications of structures
could modify the level of the second activity. When pyrazine was
used instead of pyridine as the (het)Ar moiety, an excellent dual
inhibitor was obtained. The inhibition values for compound 38
were 84 and 32 nM against CDK5 and GSK3 respectively (entry 2e).
Globally each methoxylation in C-2 diminished activity and fav-
oured the effect on GSK3; the previously mentioned duality was
lost (entries 1ce4c, 5be7b, 8).
Aryl amines 8e10 were engaged in order to generate a novel
valmerin series II. As kinase activities are directly linked to the
presence of the aryl urea function, we tried several synthetic routes.
The most convenient method remained the use of amines 8e10
which react from in situ freshly prepared isocyanates. Noteworthy,
the previously mentioned isocyanates were obtained starting from
the chosen carboxylic acids via a Curtius type rearrangement. This
route appears to be very advantageous since many heteroaromatic
carboxylic acids are commercially available. The use of this new
strategy allowed us to develop an interesting variety of ureas 11e31
with satisfying yields. The ureas carrying an acetal were engaged in
a final deprotection step to access the corresponding ketones. This
sequence is particularly interesting since the direct synthesis of
final derivatives, starting from 4 or 6, failed.
Treatment of compounds 11, 14, 17, 20 and 23 with an aqueous
solution of hydrochloric acid at 10% in refluxing acetone led to the
desired ketones 32e36 with yields of up to 79%. The final com-
pounds 37e41 were then directly isolated from ureas 32e36 by
reduction with sodium borohydride in a THF/MeOH mixture. After
Compounds bearing a ketone in C-2 position remained inactive
(entries 1d, 2d) whatever the tested kinase. It is possible that the
ꢀ
stirring for 2 h at a temperature range of 0e5 C, the final products
37e41 were straightforwardly isolated as their single cis di-
presence of a planar and p electron rich dipole was detrimental for
astereoisomers, with satisfying yields. The other stereoisomer was
never observed (TLC, H NMR of the crude material) (Scheme 3).
kinase binding. A cyclic acetal was better tolerated by the active site
despite the large size of this moiety. Valmerins which possess this
1
ꢀ
Scheme 2. Reagents and conditions: i) 1,2-ethanedithiol (5.0 eq.), BF
3
$Et
2
O (5.0 eq.), CH
2
Cl
2
, r.t., 24 h, 86%; ii) NaBH
4
(2.0 eq.), THF/MeOH (1/2), ꢁ20 C to r.t., 5 h, 86% (mixture of cis-
ꢀ
6
and trans-6); iii) Ag
2
O (4.0 eq.), CH
3
I (10.0 eq.), THF, 50 C, 48 h, 61% (from 4); iv) SnCl
2
(15.0 eq.), EtOH, r.t., 12 h, 8 80% or 10 82%; v) H
2
, Patm, Raney Ni, EtOH, r.t., 14 h, 95%.

R. Boulahjar et al. / European Journal of Medicinal Chemistry 101 (2015) 274e287
277
Scheme 3. Reagents and conditions: i) a) Et
ArNCO, dioxane, 100 C, 24 h; iii) HCl 10%, acetone, reflux, 3 h; iv) NaBH
3
N (1.3 eq.), ꢁ10 ꢀC, THF, 5 min.; b) ClCO
2
Et (1.5 eq.), ꢁ10 ꢀC, THF, 2 h; c) NaN
3
(1.7 eq.), ꢁ10 ꢀC, H
2
O, 1 h; d) toluene, reflux, 1 h; ii) (Het)
ꢀ
ꢀ
ꢀ
4
(2.0 eq.), THF/MeOH (1/1), 0 Ce5 C, 2 h. For yields see Table 1.
electron rich cycle acted preferentially on GSK3 (entries 1ae5a).
The best score was obtained with 14, which bears the dioxolane
ring in C-2 and inhibited GSK3 with an IC50 ¼ 260 nM. The activity
on CDK5 was 30 fold weaker.
DYRK1A and CDK5 is due to the large gatekeeper residue Phe
compared to Leu132 in GSK3 , creating a steric hindrance with the
tetrahydropyridoisoindolone scaffold. Additionally, the lack of ac-
tivity towards DYRK1A might be due to the larger residue Val306,
b
Surprisingly, replacing dioxolane by dithiolane enhanced the
enzymatic activities on GSK3 as well as on CDK5 (for derivatives 12,
compared to Ala143 and Cys199 in CDK5 and GSK3b respectively,
located below the plane of the scaffold and at position N-1 in the
15 and 27, entries 1b, 2b and 7a respectively). Adding a supple-
DFG motif.
mentary heavy lipophilic bromine atom on the pyridine urea
increased selectivity to a very high level (entry 10). Valmerin 31
was active on GSK3 with an IC50 of 68 nM: the selectivity toward
CDK5 increased by 100 fold.
5. Cellular screening
The toxicity on synthesized molecules was assessed on six
cancer cell lines; Huh7 (liver), Caco2 (colon), MDA-MB231 (breast),
HCT-116 (colon), PC3 (prostate), NCI H727 (lung). The molecules
were generally cytostatic, blocking cell cycle replication. These re-
sults are typical for most kinase inhibitors acting on the targeted
4
. Molecular modelling studies
To rationalize the structureeactivity relationships, the mole-
cules were docked into the binding site of GSK3
b
and CDK5. We
kinases (CDK5 and GSK3
reference.
b) such as roscovitine used in our test as a
found two main modes of binding depending on the substituent
attached to the urea moiety. In one binding mode the carboxyl
group of the tetrahydropyridoisoindolone scaffold points towards
the catalytic lysine Lys85, forming a hydrogen bond interaction and
the urea is positioned parallel to the hinge region, creating a
hydrogen bond interaction between the urea and the backbone of
Val135 [9]. A second mode of binding was more frequently
All the derivatives which were tested on the kinase assay were
evaluated on the cell line panel. Surprisingly all the derivatives
bearing an OH in C-2 position, i.e., 38, 39 and 40, led to inactive
derivatives as if the hydroxyl group was too sensitive and induced
instability in the cell culture media. Among the C-2 OMe family
which appears active against GSK3 (i.e., 13 and 29), only 29 led to
interesting cellular effects. The best inhibition of growth was ob-
tained with the colon cell line HCT-116 (IC50 ¼ 30 nM) and the liver
cell line Huh7 (IC50 ¼ 100 nM). Other cell lines were affected with
an IC50 between 300 and 500 nM.
Concerning the derivatives carrying C-2 thio acetals (12, 15, 27
and 31), cellular effects were maintained in the nanomolar range
only when the urea (het)Ar moiety was a pyrazine group which
could be unsubstituted or methylated (15 and 27). For compound
15, the cellular activity on Huh7 was similar to the one observed
with 29. The toxicity against HCT-116 remained high
(IC50 ¼ 100 nM). A real improvement on the breast cell line was
observed, with the IC50 reaching 150 nM (Table 3).
observed in GSK3
tetrahydropyridoisoindolone scaffold forms
b
and is shown on Fig. 2. The carboxyl group of the
hydrogen bond
a
interaction with the NH backbone of Val35, and the urea interacts
with the catalytic lysine Lys85. Interestingly, in this orientation the
heterocyclic ring attached to the urea can form an additional
hydrogen bond interaction with Lys85 if a nitrogen is present at the
ortho position. As shown in Fig. 2, the nitrogen of the pyridine
moiety from compound 29 interacts with Lys85, and a bidentate
hydrogen bond is now present with Lys85. This binding mode can
explain the kinase activity obtained with most of the 6-membered
rings compared to 5-membered rings such as pyrazole where there
is a drop in kinase activity probably because of the lack of this
hydrogen bond.
The substituent attached to the saturated ring of the tetrahy-
dropyridoisoindolone scaffold interacts with Thr138 through a
hydrogen bond network or van der Waals interaction depending on
the orientation of the residue side chain. Based on the binding
6. Conclusions
We have developed efficient synthetic routes able to modulate
the structure of the tetrahydropyridine skeleton. A library of more
than 30 novel final structures was generated and our valmerin li-
brary considerably enhanced biological activities on CDK5 and
mode analysis and sequence alignment of GSK3
b, CDK5 and
DYRK1A, we suggest that the low activity of the compounds for

278
R. Boulahjar et al. / European Journal of Medicinal Chemistry 101 (2015) 274e287
Table 1
Synthesis of valmerins 11e41.
Entry
(Het)Ar
R/R
1
Product
Yielda
1
2
3
4
a
b
c
d
e
eOCH
2
CH
CH
2
Oe
Se
11
12
13
32
37
78%
96%
81%
eSCH
2
2
cis OCH
]O
cis OH
3
Obtained from 11, quant.
Obtained from 32, 76%
a
b
c
d
e
eOCH
eSCH
2
CH
CH
2
Oe
Se
14
15
16
33
38
68%
90%
78%
2
2
cis OCH
]O
cis OH
3
Obtained from 14, 95%
Obtained from 33, 60%
a
b
c
d
e
eOCH
eSCH
2
CH
CH
2
Oe
Se
17
18
19
34
39
75%
78%
75%
2
2
cis OCH
]O
cis OH
3
Obtained from 17, 79%
Obtained from 34, 80%
a
b
c
d
e
eOCH
eSCH
2
CH
CH
2
Oe
Se
20
21
22
35
40
72%
80%
80%
2
2
cis OCH
]O
cis OH
3
Obtained from 20, 83%
Obtained from 35, 82%
5
6
a
b
c
eOCH
cis OCH
]O
2
CH
2
Oe
23
24
36
41
72%
73%
3
Obtained from 23, 85%
Obtained from 36, 82%
d
H/OH
a
b
eSCH
2
CH
2
Se
25
26
68%
81%
cis OCH
3
7
8
9
a
b
eSCH
cis OCH
2
CH
2
Se
27
28
85%
76%
3
cis OCH
3
29
30
76%
57%
eSCH
eSCH
2
2
CH
2
2
Se
Se
10
CH
31
82%
a
Yields are indicated for isolated products.
GSK3. Cellular effects on cancer cell lines were measured for each
novel compound. The proposed structural modifications modu-
lated the enzyme/drug recognition mechanism. Based on this novel
scaffold, we were able to develop inhibitors exhibiting in vitro
nanomolar activities on either both CDK5 and GSK3 with similar
potency or only GSK3 with a 100 fold activity factor against CDK5.
Molecular modelling provided information on the interaction of the
best candidate 29 in the GSK3 binding site. Strong interactions were
developed by the creation of hydrogen bonds, the carbonyl having
an interaction with the hinge region (NH backbone) whereas the 2-
pyridine or pyrazine urea interacts with the catalytic lysine residue.
Modulations of the structure led to the three best derivatives which
were evaluated in cellular assays. Antiproliferative effects were
found in the nanomolar range. The strong cytostatic effect induced
apoptosis in several cancer cell lines and more predominantly in
lung and colon cell lines. This novel study confirms that the val-
merin heterocyclic scaffold is of interest for the medicinal chem-
istry community and further investigations are currently in
progress to envision a development of this series.
7. Experimental section
7.1. Chemistry
1H NMR and 13C NMR spectra were recorded on a Bruker DPX
250 MHz or 400 MHz instrument using CDCl3 or DMSO-d . The
chemical shifts are reported in parts per million (d scale) and all
6
coupling constant (J) values are in Hertz (Hz). The following ab-
breviations were used to explain the multiplicities: s (singlet),
d (doublet), t (triplet), q (quartet), m (multiplet) and dd (doublet
doublet). Melting points are uncorrected. IR absorption spectra
were obtained on a Perkin Elmer PARAGON 1000 PC and values are
ꢁ1
reported in cm . HRMS were recorded on a Bruker maXis mass
spectrometer. Monitoring of the reactions was performed using
silica gel TLC plates (silica Merck 60 F254). Spots were visualized by
UV light at 254 nm and 356 nm. Column chromatographies were

R. Boulahjar et al. / European Journal of Medicinal Chemistry 101 (2015) 274e287
279
Table 2
Kinase inhibitions of derivatives 11e41.
Entry
(Het)Ar
R/R
1
Product
CDK5
GSK3
a
/b
Selectivity
DYRK1A
IC50
(
m
M)
IC50
(m
M)
CDK5/GSK3
IC50 (mM)
1
a
b
c
d
e
eOCH
eSCH
cis OCH
]O
2
CH
CH
2
Oe
Se
11
12
13
32
37
11
0.7
1.5
7.2
6.8
6.3
8.0
80
>10
>10
25
2
2
0.24
0.55
1.6
0.033
0.081
0.23
3
cis OH
2.1
0.26
34
2
3
4
a
b
c
d
e
eOCH
eSCH
cis OCH
]O
2
CH
CH
2
Oe
Se
14
15
16
33
38
7.1
0.26
0.044
0.2
1.2
0.032
27.3
3.4
2.4
3.0
2.6
93
>10
>10
50
2
2
0.15
0.48
3.6
3
cis OH
0.084
>10
a
b
c
d
e
eOCH
eSCH
2
CH
CH
2
Oe
Se
17
18
19
34
39
>10
>10
4.3
ND
1.0
0.92
2
0.32
ND
>10
>5
13.4
ND
>10
>10
>10
ND
2
2
cis OCH
]O
cis OH
3
0.030
33.3
7.0
a
b
c
d
e
eOCH
eSCH
2
CH
CH
2
Oe
Se
20
21
22
35
40
>10
>10
8.5
ND
4.9
1.0
4
0.18
ND
0.035
>10
>2.5
47.5
ND
>10
2
2
>10
>10
ND
cis OCH
]O
cis OH
3
140
>10
5
6
a
b
c
eOCH
cis OCH
]O
2
CH
2
Oe
23
24
36
41
3.1
1.1
ND
0.63
0.61
0.25
ND
5.0
4.4
ND
>10
>10
ND
3
d
cis OH
0.16
6.2
a
b
eSCH
2
CH
2
Se
25
26
ꢃ10
1.9
1.1
ꢃ5.2
>10
>10
cis OCH
3
2.3
2.0
7
8
9
a
b
eSCH
cis OCH
2
CH
2
Se
27
28
0.22
0.32
0.055
0.14
4.0
10.0
>10
>10
3
cis OCH
3
29
30
0.32
0.032
0.71
10.0
>10
eSCH
eSCH
2
CH
CH
2
Se
Se
>10
>14.0
8.7
1
0
2
2
31
7.3
0.068
107.3
ꢃ10
Assays were performed in triplicate.
performed using silica gel 60 (0.063e0.200 mm, Merck).
(t, J ¼ 7.8 Hz, 1H), 8.18 (dd, J ¼ 0.8 Hz, J ¼ 7.8 Hz, 1H), 8.36 (dd,
13
J ¼ 0.8 Hz, J ¼ 8.2 Hz, 1H). C NMR (63 MHz, CDCl
3 2
) d 38.7 (CH ),
3
9.3 (CH ), 39.4 (CH ), 40.7 (CH ), 45.5 (CH ), 59.5 (CH), 65.5 (Cq),
2
2
2
2
7
.1.1. 10-Nitro-1,3,4,10b-tetrahydro-6H-spiro[pyrido[2,1-a]
1
27.2 (CH), 130.1 (CH), 130.3 (CH), 135.9 (Cq), 139.6 (Cq), 143.8 (Cq),
0
isoindole-2,2 -[1,3]dithiolan]-6-one 5
þ
163.7 (Cq). HRMS (ESI) calcd. for C14
15
H N
2
O
3
S
2
[MþH] : 323.0524,
2 2
To a stirred solution of 3 (1.0 g, 3.4 mmol, 1.0 eq.) in CH Cl
found: 323.0509.
(
40 mL), were added drop wise, at room temperature, ethane
dithiol (1.24 mL, 17.0 mmol, 5.0 eq.) and then BF $Et O (2.15 mL,
7.0 mmol, 5.0 eq.). After 24 h of stirring at room temperature,
CH Cl (40 mL) and an aq. NaOH (1 M) solution (40 mL) were added.
After extraction with CH Cl (40 mL) the combined organic layers
were dried over MgSO , filtered and evaporated under reduced
3
2
1
7.1.2. cis-2-Hydroxy-10-nitro-1,3,4,10b-tetrahydropyrido[2,1-a]
isoindol-6(2H)-one cis-6
2
2
2
2
To a solution of compound 4 (500 mg, 2.1 mmol, 1.0 eq.) in a
4
THF/MeOH (10 mL/20 mL) mixture, NaBH
4
(155 mg, 4.2 mmol,
ꢀ
pressure. Purification by column chromatography (PE/EtOAc 40/60)
2.0 eq.) was slowly added portion wise at ꢁ20 C. The solution was
stirred at this temperature for 1 h and then at room temperature for
4 h. Water (10 mL) was added, and the aqueous phase was extracted
ꢀ
led to 5 as beige solid in 86% yield. m.p. 185e187 C. IR (ATR-Dia-
ꢁ
1
1
mond, cm
CDCl
1.51 (dd, J ¼ 11.2 Hz, J ¼ 12.9 Hz, 1H), 1.97e2.19 (m, 1H),
.21e2.35 (m, 1H), 2.97e3.10 (m, 1H), 3.19e3.36 (m, 1H), 3.37e3.56
m, 4H), 4.57e4.58 (m, 1H), 5.25 (dd, J ¼ 3.1 Hz, J ¼ 11.2 Hz, 1H), 7.69
) n 1689, 1524, 1416, 1345, 1079. H NMR (250 MHz,
3
)
d
first with CH
combined organic layers were dried over MgSO
concentrated under reduced pressure. The crude residue was
2
Cl
2
(2 ꢂ 10 mL) and then with EtOAc (10 mL). The
2
(
4
, filtered and

280
R. Boulahjar et al. / European Journal of Medicinal Chemistry 101 (2015) 274e287
Fig. 2. Binding mode representation of compound 29 in GSK3b (PDB entry 1J1B).
Table 3
Most potent Valmerins in cell line assays.
Entry
(Het)Ar
R/R
1
Product
Human cell lines IC50 (mM)
Huh7
Caco2
MDA-MB 231
HCT 116
PC3
NCIH727
1
2
e
e
Roscovitine
15
5
0.1
3
0.5
3
0.15
2
0.1
2
0.6
4
0.4
eSCH
2
CH
CH
2
2
Se
Se
3
4
eSCH
2
27
29
0.3
0.5
0.5
0.4
0.3
0.2
0.4
0.4
0.8
0.4
cis OCH
3
0.1
0.03
Assays were performed in triplicate.
purified by flash chromatography on silica gel (CH
to give cis-6 as a white solid in 14% yield. m.p. >260 C. IR (ATR-
2
Cl
2
/MeOH 95/5)
silica gel (CH
2
Cl
2
/MeOH 99/1) to afford compound 7 as a white solid
ꢀ
ꢀ
in 61% yield (calcd from 4). m.p. 132e134 C. IR (ATR-Diamond,
ꢁ
1
1
ꢁ1
1
Diamond, cm
DMSO-d
)
n
2973, 1683, 1566, 1329, 1288. H NMR (400 MHz,
cm
CDCl
)
)
n
d
1688, 1523, 1349, 1285, 1112, 941, 767. H NMR (400 MHz,
0.82 (q, J ¼ 12.5 Hz, 1H), 1.22e1.39 (m, 1H), 2.18 (d,
6
)
d
0.76 (q, J ¼ 12.5 Hz, 1H), 1.11e1.22 (m, 1H), 1.94 (d,
3
J ¼ 12.5 Hz, 1H), 2.64 (d, J ¼ 13.2 Hz, 1H), 3.08 (td, J ¼ 5.2 Hz,
J ¼ 13.2 Hz, 1H), 2.96e3.09 (m, 2H), 3.40 (s, 3H), 3.61e3.67 (m, 1H),
4.56 (dd, J ¼ 5.0 Hz, J ¼ 13.2 Hz, 1H), 4.96 (dd, J ¼ 3.2 Hz, J ¼ 11.6 Hz,
J ¼ 12.5 Hz, 1H), 3.91e3.98 (m, 1H), 4.24 (dd, J ¼ 5.2 Hz, J ¼ 12.5 Hz,
1
1
H), 5.02e5.09 (m, 2H), 7.80 (t, J ¼ 8.0 Hz, 1H), 8.11 (d, J ¼ 8.0 Hz,
1H), 7.67 (dd, J ¼ 7.5 Hz, J ¼ 8.0 Hz, 1H), 8.15 (d, J ¼ 7.5 Hz, 1H), 8.33
13
13
H), 8.39 (d, J ¼ 8.0 Hz, 1H). C NMR (100 MHz, DMSO-d
6
)
d
34.0
(d, J ¼ 8.0 Hz, 1H). C NMR (100 MHz, CDCl
3 2
) d 30.9 (CH ), 35.0
(
(
(
CH
2
), 36.8 (CH ), 38.4 (CH ), 57.9 (CH), 66.4 (CH), 127.1 (CH), 129.7
2
2
2 2 3
(CH ), 37.3 (CH ), 56.1 (CH ), 58.6 (CH), 76.8 (CH), 127.0 (CH), 129.9
CH), 130.3 (CH), 135.1 (Cq), 139.7 (Cq), 143.3 (Cq), 162.6 (Cq). HRMS
ESI) calcd. for C12
(CH), 130.1 (CH), 135.7 (Cq), 139.6 (Cq), 143.6 (Cq), 163.5 (Cq). HRMS
(ESI) calcd. for C13
þ
þ
13
H N
2
O
4
[MþH] : 249.0870, found: 249.0871.
H
15
N
2
O
4
[MþH] : 263.1026, found: 263.1030.
7
.1.3. cis-2-Methoxy-10-nitro-1,3,4,10b-tetrahydropyrido[2,1-a]
isoindol-6(2H)-one 7
To the solution of 6 (mixture cis and trans, 100 mg, 0.4 mmol,
.0 eq.) in dry THF (5 mL), were added MeI (0.25 mL, 4.0 mmol,
0.0 eq.) and freshly prepared Ag O (37.0 mg,1.6 mmol, 4.0 eq.). The
mixture was stirred at 50 C for 24 h. After cooling to room tem-
perature, the precipitate was filtered, washed with CH Cl
3 ꢂ 10 mL) and the combined organic layers were concentrated in
vacuum. The residue was purified by column chromatography on
7.1.4. 10-Amino-1,3,4,10b-tetrahydro-6H-spiro[pyrido[2,1-a]
isoindole-2,2 -[1,3]di-thiolan]-6-one 8
To a stirred solution of 5 (800 mg, 2.4 mmol) in EtOH (20 mL)
2
was added SnCl (6.8 g, 36.0 mmol, 15.0 eq.). The mixture was
0
1
1
2
stirred overnight then solvent was evaporated in vacuum keeping
ꢀ
ꢀ
the temperature of the solution below 30 C. The residue was
ꢀ
2
2
cooled at 0 C then neutralized successively by an aqueous NaOH
(
(2 M) solution. After extraction with CH
2 2
Cl (40 mL), the combined
organic layers were dried over MgSO , filtered and evaporated in
4

R. Boulahjar et al. / European Journal of Medicinal Chemistry 101 (2015) 274e287
281
vacuum. The crude residue was purified by silica gel chromatog-
raphy (CH Cl /MeOH 99/1) to give compound 8 as yellow solid in
0% yield. m.p. 204e206 C. IR (ATR-Diamond, cm
7.1.8. 1-(6-Oxo-3,4,6,10b-tetrahydro-1H-spiro[pyrido[2,1-a]
isoindole-2,2 -[1,3]dioxolan]-10-yl)-3-(pyridin-2-yl)urea 11
Compound 11 was obtained following the general procedure A
from the amine 10 and pyridin-2-carboxylic acid after purification
0
2
2
ꢀ
ꢁ1
n
8
)
3236, 1675,
1
1
487, 1287, 1003. H NMR (250 MHz, CDCl ) d 1.63e1.77 (m, 1H),
3
2
.02 (td, J ¼ 5.1 Hz, J ¼ 12.9 Hz, 1H), 2.13e2.24 (m, 1H), 2.78e2.92
by flash chromatography (CH
78% yield. m.p. 178e180 C. IR (ATR-Diamond, cm
1651, 1529e1485e1427, 1288, 1200, 723. H NMR (400 MHz, DMSO-
2
Cl
2
/MeOH 99/1) as a white solid in
ꢀ
ꢁ1
(
m, 1H), 3.23 (td, J ¼ 3.2 Hz, J ¼ 13.3 Hz, 1H), 3.31e3.50 (m, 4H), 3.81
) n 3305e3224,
1
(
br s, 2H), 4.41e4.60 (m, 2H), 6.80 (dd, J ¼ 1.3 Hz, J ¼ 7.2 Hz, 1H),
7
.17e7.37 (m, 2H). 13C NMR (63 MHz, CDCl
3
)
d
38.4 (CH
2
), 38.7
d
6
)
d
1.27 (t, J ¼ 12.3 Hz, 1H), 1.50 (td, J ¼ 5.7 Hz, J ¼ 13.1, 1H), 1.85 (d,
(
(
(
CH
2
), 39.7 (CH
2
), 41.6 (CH
2
), 45.7 (CH
2
), 57.1 (CH), 65.7 (Cq), 114.3
J ¼ 13.1 Hz, 1H), 2.62 (dd, J ¼ 2.1 Hz, J ¼ 9.3 Hz, 1H), 3.16 (td,
J ¼ 3.4 Hz, J ¼ 13.1 Hz, 1H), 3.85 (dd, J ¼ 6.3 Hz, J ¼ 14.1 Hz, 1H), 3.96
(dt, J ¼ 6.3 Hz, J ¼ 12.3 Hz, 1H), 4.01e4.09 (m, 2H), 4.29 (dd,
J ¼ 4.7 Hz, J ¼ 13.1 Hz, 1H), 4.81 (dd, J ¼ 3.4 Hz, J ¼ 12.3 Hz, 1H), 7.09
CH), 118.4 (CH), 129.0 (Cq), 129.7 (CH), 133.3 (Cq), 141.4 (Cq), 166.7
Cq). HRMS (ESI) calcd. for C14
þ
H
17
N
2
OS
2
[MþH] : 293.0782, found:
2
93.0774.
(
1
9
dd, J ¼ 5.5 Hz, J ¼ 6.8 Hz, 1H), 7.26 (d, J ¼ 8.3 Hz, 1H), 7.36e7.43 (m,
H), 7.47 (t, J ¼ 7.7 Hz, 1H), 7.74e7.86 (m, 1H), 8.21e8.35 (m, 2H),
13
7.1.5. cis-10-Amino-2-methoxy-1,3,4,10b-tetrahydropyrido[2,1-a]
.95 (s, 1H), 11.42 (s, 1H). C NMR (100 MHz, DMSO-d 33.0
6
)
d
isoindol-6(2H)-one 9
To a stirred solution of compound 7 (1.0 g, 3.8 mmol) in absolute
EtOH (30 mL) was added freshly prepared W Raney Nikel (ca
(
(
(
(
CH
2
), 36.1 (CH ), 38.3 (CH ), 55.5 (CH), 64.0 (CH ), 64.3 (CH ), 106.8
2
2
2
2
Cq), 112.1 (CH), 117.5 (CH), 117.6 (CH), 122.5 (CH), 129.1 (CH), 132.7
Cq), 133.9 (Cq), 134.2 (Cq), 139.1 (CH), 146.0 (CH), 152.1 (Cq), 152.9
Cq),164.8 (Cq). HRMS (ESI) calc. for C20
2
00 mg). The resulting suspension was hydrogenated (1 atm) at
room temperature for 14 h. The mixture was filtered through a pad
of celite and washed with CH Cl
þ
H
21
N
4
O
4
[MþH] : 381.1563,
found: 381.1553.
2
2
(3 ꢂ 10 mL). The combined
organic layers were concentrated under vacuum to give compound
9
cm
ꢀ
7.1.9. 1-(6-Oxo-3,4,6,10b-tetrahydro-1H-spiro[pyrido[2,1-a]
as a yellow solid in 95% yield. m.p. 60e62 C. IR (ATR-Diamond,
0
ꢁ
1
1
isoindole-2,2 -[1,3]dithiolan]-10-yl)-3-(pyridin-2-yl)urea 12
3
) n 3236, 1683, 1566, 1288. H NMR (250 MHz, CDCl ) d 1.05 (q,
Compound 12 was obtained following the general procedure A
from the amine 8 and pyridin-2-carboxylic acid after purification
J ¼ 12.2 Hz, 1H), 1.34e1.41 (m, 1H), 2.18 (d, J ¼ 12.2 Hz, 1H), 2.80 (d,
J ¼ 12.2 Hz, 1H), 2.96 (td, J ¼ 2.5 Hz, J ¼ 12.0 Hz, 1H), 3.40 (s, 3H),
by flash chromatography (CH
2
Cl
2
/MeOH 99/1) as a white solid in a
3
1
.52e3.62 (m, 1H), 3.82 (br s, 2H), 4.30 (dd, J ¼ 5.0 Hz, J ¼ 12.0 Hz,
ꢀ
ꢁ1
96% yield. m.p. 242e244 C. IR (ATR-Diamond, cm
) n 1703, 1677,
H), 4.54 (dd, J ¼ 5.0 Hz, J ¼ 11.7 Hz,1H), 6.80 (d, J ¼ 8.5 Hz,1H), 7.25
1
m, 2H). 1 C NMR (63 MHz, CDCl
3
6
1553, 1510, 1483, 1418, 1310, 1153. H NMR (400 MHz, DMSO-d )
(
(
(
3
)
d
30.9 (CH
2
), 35.5 (CH
2
), 37.0
d
1.22e1.37 (m, 1H), 1.75 (t, J ¼ 11.3 Hz, 1H), 1.92 (d, J ¼ 13.3 Hz, 1H),
2 3
CH ), 55.9 (CH ), 56.2 (CH), 77.1 (CH), 114.2 (CH), 118.3 (CH), 129.0
Cq), 129.4 (CH), 133.2 (Cq), 141.2 (Cq), 166.6 (Cq). HRMS (ESI) calcd.
2
.72 (dd, J ¼ 2.6 Hz, J ¼ 12.6 Hz, 1H), 2.97e3.14 (m, 1H), 3.23e3.52
þ
(m, 4H), 4.27 (dd, J ¼ 4.4 Hz, J ¼ 13.0 Hz, 1H), 4.59 (dd, J ¼ 3.3 Hz,
J ¼ 11.5 Hz, 1H), 7.03e7.12 (m, 1H), 7.34 (d, J ¼ 8.3 Hz, 1H), 7.39 (dd,
J ¼ 0.8 Hz, J ¼ 7.4 Hz, 1H), 7.45 (t, J ¼ 7.7 Hz, 1H), 7.75e7.86 (m, 1H),
for C13
H
17
N
2
O
2
[MþH] : 233.1285, found: 233.1289.
7.1.6. 10-Amino-1,3,4,10b-tetrahydro-6H-spiro[pyrido[2,1-a]
8
.23 (d, J ¼ 7.9 Hz, 1H), 8.26e8.33 (m, 1H), 10.00 (s, 1H), 11.17 (s, 1H).
0
isoindole-2,2 -[1,3] dioxolan]-6-one 10
Derivative 10 was prepared from 3 as previously described for 8.
The crude residue was purified by silica gel chromatography
13
C NMR (100 MHz, DMSO-d
0.7 (CH ), 44.1 (CH ), 56.9 (CH), 65.6 (Cq), 112.1 (CH), 117.4 (CH),
17.8 (CH), 123.6 (CH), 129.1 (CH), 132.7 (Cq), 133.8 (Cq), 134.1 (Cq),
6 2 2 2
) d 37.7 (CH ), 38.2 (CH ), 38.9 (CH ),
4
1
2
2
(
CH
2 2
Cl /MeOH 99/1) to give compound 10 as a white solid in 82%
139.1 (CH), 146.4 (CH), 152.2 (Cq), 152.9 (Cq), 164.8 (Cq). HRMS (ESI)
ꢀ
ꢁ1
n
yield. m.p. 76e78 C. IR (ATR-Diamond, cm
)
1710, 1542, 1366,
þ
calc. for C20
20
H N
4
O
2
S
2
Na [MþNa] : 435.0878, found: 435.0870.
1
3
1143, 1028. H NMR (250 MHz, CDCl ) d
1.38 (t, J ¼ 12.5 Hz, 1H), 1.67
(
1
td, J ¼ 5.7 Hz, J ¼ 13.0 Hz, 1H), 1.81e1.83 (m, 1H), 2.44e2.46 (m,
7.1.10. cis-1-(2-Methoxy-6-oxo-1,2,3,4,6,10b-hexahydropyrido[2,1-
H), 3.23 (td, J ¼ 3.9 Hz, J ¼ 13.0 Hz, 1H), 3.74 (br s, 2H), 3.99e4.14
a]isoindol-10-yl)-3-(pyridin-2-yl)urea 13
Compound 13 was prepared following the general procedure A
from the amine 9 and pyridin-2-carboxylic acid after purification
(
7
(
(
(
m, 4H), 4.41e4.61 (m, 2H), 6.81 (dd, J ¼ 1.8 Hz, J ¼ 7.0 Hz, 1H),
.24e7.36 (m, 2H). 13C NMR (63 MHz, CDCl
34.1 (CH ), 36.6
CH ), 39.1 (CH ), 55.8 (CH), 64.9 (CH ), 65.1 (CH ), 107.7 (Cq), 114.5
CH), 118.4 (CH), 129.5 (Cq), 129.6 (CH), 133.5 (Cq), 141.2 (Cq), 166.8
Cq). HRMS (ESI) calc. for C14
3
)
d
2
2
2
2
2
by flash chromatography (CH
2
Cl
2
/MeOH 99/1) as a yellow solid in
ꢀ
ꢁ1
81% yield. m.p. 166e168 C. IR (ATR-Diamond, cm
)
n
1688, 1602,
1.04
þ
H
17
N
2
O
3
[MþH] : 261.1239, found:
1
1579, 1478, 1418, 1312, 1291, 751. H NMR (400 MHz, CDCl
3
)
d
2
61.1238.
(
3
q, J ¼ 12.5 Hz, 1H), 1.13e1.42 (m, 1H), 2.21 (d, J ¼ 12.5 Hz, 1H),
.01e3.09 (m, 2H), 3.37 (s, 3H), 3.59e3.65 (m, 1H), 4.60 (dd,
7
.1.7. General procedure A for the urea synthesis
Under Argon, a stirred solution of carboxylic acid (0.37 mmol,
J ¼ 3.2 Hz, J ¼ 12.5 Hz, 2H), 6.90 (d, J ¼ 8.0 Hz, 1H), 7.01 (dd,
J ¼ 7.5 Hz, J ¼ 8.0 Hz,1H), 7.49 (dd, J ¼ 7.5 Hz, J ¼ 8.0 Hz, 1H), 7.64 (d,
J ¼ 7.5 Hz, 1H), 7.70 (td, J ¼ 7.5 Hz, J ¼ 8.0 Hz, 1H), 8.15 (d, J ¼ 8.0 Hz,
3
1.0 eq.) and Et N (0.48 mmol, 1.3 eq.) in dry THF (7 mL) was cooled
ꢀ
13
to ꢁ10 C. Ethyl chloroformate (0.55 mmol, 1.5 eq.) was drop wise
added and the resulting mixture was stirred for 2 h. Afterwards, a
solution of sodium azide (0.63 mmol, 1.7 eq.) in water (2 mL) was
1H), 8.26 (d, J ¼ 4.0 Hz, 1H), 8.66 (s, 1H), 11.98 (s, 1H). C NMR
3 2 2 2 3
(100 MHz, CDCl ) d 30.7 (CH ), 35.6 (CH ), 37.1 (CH ), 55.9 (CH ),
57.0 (CH), 77.4 (CH), 112.4 (CH), 117.7 (CH), 119.5 (CH), 124.5 (CH),
129.4 (CH), 133.2 (Cq), 133.3 (Cq), 135.0 (Cq), 139.2 (CH), 145.5 (CH),
ꢀ
added in one portion. After 1 h at ꢁ10 C, the reaction was found to
be complete (TLC) and was quenched into iced water (5 mL). The
152.7 (Cq), 153.3 (Cq), 166.0 (Cq). HRMS (ESI) calc. for C19
[MþH] : 353.1614, found: 353.1603.
H
21
N
4
O
3
þ
mixture was extracted with EtOAc (3 ꢂ 10 mL) and the combined
4
organic layers were successively dried over MgSO , filtered and
evaporated. The crude acyl azide was placed in dry toluene (20 mL)
and heated at reflux for 1 h to give the corresponding crude iso-
cyanate. The latter was placed in dry dioxane (7 mL) prior to adding
the appropriate amine 8, 9 or 10 (0.37 mmol, 1.0 eq.). The solution
7.1.11. 1-(6-Oxo-3,4,6,10b-tetrahydro-1H-spiro[pyrido[2,1-a]
isoindole-2,2 -[1,3]dioxolan]-10-yl)-3-(pyrazin-2-yl)urea 14
Compound 14 was obtained following the general procedure A
from the amine 10 and pyrazin-2-carboxylic acid after purification
0
ꢀ
was heated at 100 C for 24 h. The reaction mixture was cooled and
by flash chromatography (CH
in 68% yield. m.p. >260 C. IR (ATR-Diamond, cm
2
Cl
2
/MeOH 99/1) as a pale brown solid
ꢀ
ꢀ
ꢁ1
the volatiles were removed to dryness in vacuum at 40 C.
) n 1698, 1570,

282
R. Boulahjar et al. / European Journal of Medicinal Chemistry 101 (2015) 274e287
1
1
549e1504e1478, 1298, 1244, 1073. H NMR (400 MHz, DMSO-d
6
)
2 2 2
(CH ), 55.5 (CH), 63.5 (CH ), 63.6 (CH ), 106.4 (Cq), 108.3 (CH), 115.7
d
1.23 (t, J ¼ 12.3 Hz, 1H), 1.51 (td, J ¼ 5.7 Hz, J ¼ 13.1 Hz, 1H), 1.83 (d,
(CH), 118.7 (CH), 124.9 (CH), 128.1 (CH), 131.8 (Cq), 132.3 (Cq), 135.1
J ¼ 13.1 Hz, 1H), 2.55 (d, J ¼ 11.5 Hz, 1H), 3.15 (td, J ¼ 4.0 Hz,
J ¼ 13.1 Hz, 1H), 3.83e4.00 (m, 2H), 4.01e4.14 (m, 2H), 4.28 (dd,
J ¼ 4.0 Hz, J ¼ 13.3 Hz, 1H), 4.78 (dd, J ¼ 3.6 Hz, J ¼ 12.0 Hz, 1H), 7.43
(Cq), 138.2 (CH), 151.4 (Cq), 152.9 (Cq), 154.4 (Cq), 165.1 (Cq). HRMS
þ
(ESI) calc. for C21
23
H N
4
O
4
[MþH] : 395.1719, found: 395.1733.
(
8
d, J ¼ 6.9 Hz, 1H), 7.49 (t, J ¼ 7.8 Hz, 1H), 8.13 (d, J ¼ 7.8 Hz, 1H),
13
7.1.15. 1-(6-Methylpyridin-2-yl)-3-(6-oxo-3,4,6,10b-tetrahydro-
.25e8.34 (m, 2H), 8.88 (s, 1H), 10.03 (s, 1H), 10.12 (s, 1H). C NMR
33.1 (CH ), 36.1 (CH ), 38.1 (CH ), 55.5 (CH),
), 106.8 (Cq), 118.0 (CH), 123.3 (CH), 129.1 (CH),
0
1
H-spiro[pyrido[2,1-a] isoindole-2,2 -[1,3]dithiolan]-10-yl)urea 18
(
100 MHz, DMSO-d
6
)
d
2
2
2
Compound 18 was prepared following the general procedure A
from the amine 8 and 6-methylpicolinic acid after purification by
6
1
1
2 2
4.0 (CH ), 64.3 (CH
32.8 (Cq), 133.5 (Cq), 134.8 (Cq), 135.5 (CH), 137.8 (CH), 140.8 (CH),
flash chromatography (CH
yield. m.p. 154e156 C. IR (ATR-Diamond, cm
2
Cl
2
/MeOH 99/1) as a white solid in 78%
49.2 (Cq),151.7 (Cq),164.7 (Cq). HRMS (ESI) calc. for C19
19
H N
5
O
4
Na
ꢀ
ꢁ1
þ
)
n
2922, 1689, 1622,
1.61 (t,
[MþNa] : 404.1335, found: 404.1327.
1
1596, 1429, 1355, 1290, 741. H NMR (400 MHz, CDCl
3
)
d
J ¼ 12.5 Hz, 1H), 2.03 (td, J ¼ 5.0 Hz, J ¼ 12.5 Hz, 1H), 2.18 (d,
7
.1.12. 1-(6-Oxo-3,4,6,10b-tetrahydro-1H-spiro[pyrido[2,1-a]
0
J ¼ 12.5 Hz, 1H), 2.60 (s, 3H), 2.89 (d, J ¼ 13.5 Hz, 1H), 3.14e3.29 (m,
isoindole-2,2 -[1,3]dithiolan]-10-yl)-3-(pyrazin-2-yl)urea 15
Compound 15 was obtained following the general procedure A
from the amine 8 and pyrazin-2-carboxylic acid after purification
by flash chromatography (CH
9
5
H), 4.53 (dd, J ¼ 2.5 Hz, J ¼ 13.5 Hz, 1H), 4.92 (dd, J ¼ 2.5 Hz,
J ¼ 13.5 Hz, 1H), 6.83 (d, J ¼ 8.0 Hz, 2H), 7.47 (dd, J ¼ 7.5 Hz,
J ¼ 8.0 Hz, 1H), 7.58e7.65 (m, 1H), 7.68 (d, J ¼ 8.0 Hz, 1H), 7.75 (d,
2
Cl
2
/MeOH 99/1) as a white solid in
13
ꢀ
ꢁ1
J ¼ 8.0 Hz, 1H), 9.48 (s, 1H), 12.05 (s, 1H). C NMR (100 MHz, CDCl
3
)
0% yield. m.p. 236e238 C. IR (ATR-Diamond, cm
)
n
1676, 1551,
1.63
1
d
3 2 2 2 2
29.3 (CH ), 38.3 (CH ), 38.6 (CH ), 38.8 (CH ), 40.5 (CH ), 45.1
1505e1483e1421, 1298, 1138. H NMR (400 MHz, DMSO-d
6
)
d
(
(
1
CH ), 57.8 (CH), 65.5 (Cq), 109.8 (CH), 116.8 (CH), 120.4 (CH), 127.0
2
(
t, J ¼ 12.3 Hz, 1H), 1.96 (td, J ¼ 5.0 Hz, J ¼ 12.3 Hz, 1H), 2.14 (d,
CH), 129.1 (2 CH), 132.4 (Cq), 133.4 (Cq), 136.8 (2 Cq), 152.1 (Cq),
J ¼ 13.2 Hz, 1H), 2.89 (d, J ¼ 11.5 Hz, 1H), 3.16 (td, J ¼ 3.1 Hz,
J ¼ 13.3 Hz, 1H), 3.28e3.48 (m, 4H), 4.33 (dd, J ¼ 3.1 Hz, J ¼ 13.3 Hz,
þ
54.0 (Cq), 165.8 (Cq). HRMS (ESI) calc. for C21
27.1262, found: 427.1278.
H
23
N
4
O
S
2 2
[MþH] :
4
1
H), 4.79 (dd, J ¼ 3.1 Hz, J ¼ 11.5 Hz, 1H), 7.42e7.54 (m, 2H), 8.08
(
dd, J ¼ 0.9 Hz, J ¼ 7.8 Hz, 1H), 8.29 (d, J ¼ 2.7 Hz, 1H), 8.40 (dd,
J ¼ 1.5 Hz, J ¼ 2.6 Hz, 1H), 8.83 (d, J ¼ 1.1 Hz, 1H), 10.13 (s, 1H), 10.19
7.1.16. cis-1-(2-Methoxy-6-oxo-1,2,3,4,6,10b-hexahydropyrido[2,1-
13
(
(
(
(
s, 1H). C NMR (100 MHz, DMSO-d
CH ), 40.5 (CH ), 44.0 (CH ), 56.9 (CH), 65.6 (Cq), 118.3 (CH), 124.1
CH), 129.1 (CH), 132.8 (Cq), 133.4 (Cq), 134.7 (Cq), 135.6 (CH), 137.7
CH), 140.8 (CH), 149.2 (Cq), 151.7 (Cq), 164.7 (Cq). HRMS (ESI) calc.
6 2 2
) d 37.7 (CH ), 38.2 (CH ), 38.7
a]isoindol-10-yl)-3-(6-methyl-pyridin-2-yl)urea 19
Compound 19 was prepared from following the general proce-
dure A from the amine 9 and 6-methylpicolinic acid after purifi-
2
2
2
cation by flash chromatography (CH
2
Cl
2
/MeOH 99/1) as a white
þ
for C19
19
H N
5
O
2
S
2
Na [MþNa] : 436.0878, found: 436.0870.
ꢀ
ꢁ1
solid in 75% yield. m.p.167e169 C. IR (ATR-Diamond, cm
)
n
1689,
1
1
589, 1556, 1436, 1283, 751. H NMR (400 MHz, CDCl
3
)
d
1.03 (q,
7.1.13. cis-1-(2-Methoxy-6-oxo-1,2,3,4,6,10b-hexahydropyrido[2,1-
J ¼ 12.5 Hz, 1H), 1.27e1.38 (m, 1H), 2.19 (d, J ¼ 12.5 Hz, 1H), 2.56 (s,
a]isoindol-10-yl)-3-(pyrazin-2-yl)urea 16
Compound 16 was prepared following the general procedure A
from the amine 9 and pyrazin-2-carboxylic acid after purification
by flash chromatography (CH
7
3
3
4
H), 2.93 (d, J ¼ 12.5 Hz, 1H), 3.02 (td, J ¼ 3.2 Hz, J ¼ 13.5 Hz, 1H),
.30 (s, 3H), 3.53e3.59 (m, 1H), 4.58 (dd, J ¼ 4.5 Hz, J ¼ 13.5 Hz, 1H),
.69 (dd, J ¼ 3.2 Hz, J ¼ 12.5 Hz, 1H), 6.70 (d, J ¼ 8.0 Hz, 1H), 6.83 (d,
2
Cl
2
/MeOH 99/1) as a yellow solid in
J ¼ 7.5 Hz, 1H), 7.49 (dd, J ¼ 7.5 Hz, J ¼ 8.0 Hz, 1H), 7.55 (dd,
ꢀ
ꢁ1
8% yield. m.p. 192e194 C. IR (ATR-Diamond, cm
) n 1684, 1595,
J ¼ 7.5 Hz, J ¼ 8.0 Hz, 1H), 7.66 (d, J ¼ 8.0 Hz, 1H), 7.99 (d, J ¼ 8.0 Hz,
1
1557, 1486, 1421, 1306, 1084, 753. H NMR (400 MHz, DMSO-d
6
)
13
1H), 8.93 (s, 1H), 11.98 (s, 1H). C NMR (100 MHz, CDCl
3
)
d
24.4
d
0.80 (q, J ¼ 12.5 Hz, 1H), 1.14e1.24 (m, 1H), 2.19 (d, J ¼ 12.5 Hz, 1H),
(
(
(
(
3 2 2 2 3
CH ), 30.6 (CH ), 35.1 (CH ), 37.1 (CH ), 55.8 (CH ), 57.2 (CH), 77.3
CH), 109.4 (CH), 117.0 (CH), 120.0 (CH), 125.8 (CH), 129.2 (CH), 133.0
2
3
.97 (d, J ¼ 13.5 Hz, 1H), 3.14 (td, J ¼ 3.2 Hz, J ¼ 12.5 Hz, 1H), 3.28 (s,
H), 3.69e3.77 (m, 1H), 4.34 (dd, J ¼ 4.0 Hz, J ¼ 13.5 Hz, 1H), 4.73
Cq), 133.4 (Cq), 135.8 (Cq), 139.2 (CH), 152.3 (Cq), 153.7 (Cq), 155.0
(
dd, J ¼ 3.2 Hz, J ¼ 13.5 Hz, 1H), 7.47 (d, J ¼ 8.0 Hz, 1H), 7.54 (dd,
þ
Cq),166.0 (Cq). HRMS (ESI) calc. for C20
23
H N
4
O
3
[MþH] : 367.1770,
J ¼ 7.8 Hz, J ¼ 8.0 Hz, 1H), 8.20 (d, J ¼ 8.0 Hz, 1H), 8.35 (d, J ¼ 3.2 Hz,
found: 367.1776.
1
(
3
H), 8.40 (dd, J ¼ 1.6 Hz, J ¼ 3.2 Hz, 1H), 9.00 (d, J ¼ 1.6 Hz, 1H), 9.85
s, 1H), 10.14 (s, 1H). 13C NMR (100 MHz, DMSO-d
30.7 (CH ),
), 55.8 (CH), 76.3 (CH), 118.0 (CH),
6
)
d
2
5.3 (CH
2
), 36.4 (CH
2
), 55.2 (CH
3
7.1.17. 1-(4-Methoxyquinolin-2-yl)-3-(6-oxo-3,4,6,10b-tetrahydro-
0
123.1 (CH), 129.1 (CH), 132.8 (Cq), 133.5 (Cq), 134.5 (Cq), 135.5 (CH),
1H-spiro[pyrido[2,1-a] isoindole-2,2 -[1,3]dioxolan]-10-yl)urea 20
1
37.9 (CH), 141.1 (CH), 149.2 (Cq), 151.7 (Cq), 164.6 (Cq). HRMS (ESI)
Compound 20 was prepared following the general procedure A
from the amine 10 and 4-methoxyquinoline-2-carboxylic acid after
þ
calc. for C18
H
19
N
5
O
3
Na [MþNa] : 376.1386, found: 376.1370.
purification by flash chromatography (CH
yellow solid in 72% yield. m.p. 258e260 C. IR (ATR-Diamond,
2
Cl
2
/MeOH 99/1) as a
ꢀ
7
1
.1.14. 1-(6-Methylpyridin-2-yl)-3-(6-oxo-3,4,6,10b-tetrahydro-
H-spiro[pyrido[2,1-a] isoindole-2,2 -[1,3]dioxolan]-10-yl)urea 17
0
ꢁ1
1
cm
(400 MHz, CDCl
) n 2967, 1689, 1621, 1585, 1414, 1332, 1289, 751. H NMR
Compound 17 was prepared following the general procedure A
3
)
d
1.38 (t, J ¼ 12.5 Hz, 1H), 1.62e1.81 (m, 2H), 2.72
from the amine 10 and 6-methylpicolinic acid after purification by
flash chromatography (CH
yield. m.p. 240e242 C. IR (ATR-Diamond, cm
(d, J ¼ 13.5 Hz, 1H), 3.27e3.39 (m, 2H), 3.59e3.77 (m, 3H), 4.02 (s,
3H), 4.56 (dd, J ¼ 2.5 Hz, J ¼ 13.5 Hz, 1H), 5.01 (dd, J ¼ 2.5 Hz,
J ¼ 13.5 Hz, 1H), 6.47 (s, 1H), 7.38e7.49 (m, 2H), 7.67e7.73 (m, 2H),
7.95 (d, J ¼ 7.5 Hz,1H), 8.10 (d, J ¼ 7.5 Hz,1H), 8.23 (d, J ¼ 7.5 Hz,1H),
2
Cl
2
/MeOH 99/1) as a white solid in 75%
ꢀ
ꢁ1
)
n
3180, 1685, 1584,
1.33 (t,
1
1560, 1510, 1327, 1287, 751. H NMR (400 MHz, CDCl
3
)
d
13
J ¼ 12.5 Hz, 1H), 1.69 (td, J ¼ 5.0 Hz, J ¼ 12.5 Hz, 1H), 1.80 (d,
J ¼ 12.5 Hz, 1H), 2.53 (d, J ¼ 13.5 Hz, 1H), 2.60 (s, 3H), 3.27 (td,
J ¼ 2.5 Hz, J ¼ 13.5 Hz, 1H), 3.74e4.05 (m, 4H), 4.53 (dd, J ¼ 5.0 Hz,
J ¼ 12.5 Hz, 1H), 4.93 (dd, J ¼ 2.5 Hz, J ¼ 12.5 Hz, 1H), 6.73 (d,
J ¼ 7.5 Hz, 1H), 6.82 (d, J ¼ 7.5 Hz, 1H), 7.47e7.59 (m, 2H), 7.67 (d,
9.86 (s, 1H), 12.57 (s, 1H). C NMR (100 MHz, CDCl
3
)
d
34.1 (CH
2
2
),
),
36.6 (CH ), 38.3 (CH ), 55.8 (CH ), 56.5 (CH), 64.5 (CH ), 64.6 (CH
2 2 3 2
91.5 (CH), 107.2 (Cq), 118.8 (Cq), 119.6 (CH), 121.9 (CH), 124.2 (CH),
125.3 (CH), 126.5 (CH), 128.8 (CH), 130.5 (CH), 133.0 (Cq), 133.3 (Cq),
135.7 (Cq), 145.9 (Cq), 153.4 (Cq), 154.4 (Cq), 163.9 (Cq), 166.1 (Cq).
13
þ
J ¼ 7.5 Hz, 1H), 7.99 (d, J ¼ 7.5 Hz, 1H), 9.16 (s, 1H), 12.14 (s, 1H).
C
HRMS (ESI) calc. for
461.1844.
C
25
H
25
N
4
O
5
[MþH] : 461.1825, found:
3 3 2 2
NMR (100 MHz, CDCl ) d 22.8 (CH ), 33.0 (CH ), 35.5 (CH ), 37.2

R. Boulahjar et al. / European Journal of Medicinal Chemistry 101 (2015) 274e287
283
7
1
.1.18. 1-(4-Methoxyquinolin-2-yl)-3-(6-oxo-3,4,6,10b-tetrahydro-
H-spiro[pyrido[2,1-a] isoindole-2,2 -[1,3]dithiolan]-10-yl)urea 21
Compound 21 was prepared following the general procedure A
flash chromatography (CH
yield. m.p. 222e224 C. IR (ATR-Diamond, cm
1484, 1421, 1298, 1189, 751. H NMR (400 MHz, CDCl
2
Cl
2
/MeOH 99/1) as a yellow solid in 73%
0
ꢀ
ꢁ1
)
n
1692,1592,1554,
1.02 (q,
1
3
)
d
from the amine 8 and 4-methoxyquinoline-2-carboxylic acid after
purification by flash chromatography (CH Cl /MeOH 99/1) as a
yellow solid in 80% yield. m.p. 250e252 C. IR (ATR-Diamond,
J ¼ 12.5 Hz, 1H), 1.30e1.40 (m, 1H), 2.20 (d, J ¼ 12.5 Hz, 1H), 2.31 (s,
3H), 3.03 (td, J ¼ 3.2 Hz, J ¼ 12.5 Hz, 2H), 3.36 (s, 3H), 3.60e3.65 (m,
1H), 4.58 (dd, J ¼ 3.2 Hz, J ¼ 12.0 Hz, 2H), 6.95 (dd, J ¼ 7.5 Hz,
J ¼ 8.0 Hz, 1H), 7.11 (s, 1H), 7.46 (dd, J ¼ 7.5 Hz, J ¼ 8.0 Hz, 1H), 7.53
(d, J ¼ 7.5 Hz,1H), 7.61 (d, J ¼ 7.5 Hz, 1H), 8.13e8.16 (m, 2H), 12.24 (s,
2
ꢀ
2
ꢁ
1
1
cm
)
n
2975, 1685, 1621, 1585, 1414, 1332, 1289, 751. H NMR
1.68 (t, J ¼ 12.5 Hz, 1H), 2.06 (td, J ¼ 5.0 Hz,
(
400 MHz, CDCl ) d
3
13
J ¼ 12.5 Hz, 1H), 2.19 (d, J ¼ 12.5 Hz, 1H), 2.47e2.57 (m, 1H),
1H). C NMR (100 MHz, CDCl
3
)
d
3 2 2
17.1 (CH ), 30.9 (CH ), 35.7 (CH ),
2
4
1
.78e3.13 (m, 4H), 3.19 (td, J ¼ 5.0 Hz, J ¼ 13.5 Hz, 1H), 4.00 (s, 3H),
.58 (dd, J ¼ 2.5 Hz, J ¼ 13.5 Hz, 1H), 5.07 (dd, J ¼ 2.5 Hz, J ¼ 12.5 Hz,
H), 6.48 (s, 1H), 7.39 (dd, J ¼ 7.5 Hz, J ¼ 8.0 Hz, 1H), 7.49 (d,
37.2 (CH ), 56.1 (CH
2
3
), 57.1 (CH), 77.6 (CH), 117.9 (CH), 119.6 (CH),
119.7 (Cq), 124.6 (CH), 129.5 (CH), 133.2 (Cq), 133.3 (Cq), 135.0 (Cq),
139.9 (CH), 143.2 (CH), 151.2 (Cq), 152.7 (Cq), 166.2 (Cq). HRMS (ESI)
þ
J ¼ 7.5 Hz, 1H), 7.64 (dd, J ¼ 7.5 Hz, J ¼ 8.0 Hz, 1H), 7.72 (d, J ¼ 7.5 Hz,
calc. for C20
23
H N
4
O
3
[MþH] : 367.1770, found: 367.1778.
1
H), 8.00 (dd, J ¼ 7.5 Hz, J ¼ 8.0 Hz, 2H), 8.08 (d, J ¼ 7.5 Hz,1H),10.01
13
(
(
(
(
(
(
s, 1H), 12.56 (s, 1H). C NMR (100 MHz, CDCl
CH ), 39.0 (CH ), 40.2 (CH ), 45.4 (CH ), 55.8 (CH
Cq), 91.5 (CH), 118.7 (Cq), 120.2 (CH), 121.8 (CH), 124.2 (CH), 126.8
CH), 127.0 (CH), 128.7 (CH), 130.4 (CH), 132.7 (Cq), 133.4 (Cq), 136.4
Cq), 145.8 (Cq), 153.4 (Cq), 154.6 (Cq), 163.9 (Cq), 165.9 (Cq). HRMS
3
)
d
38.2 (CH
2
), 38.3
7.1.22. 1-(1-Methyl-1H-pyrazol-3-yl)-3-(6-oxo-3,4,6,10b-
0
2
2
2
2
3
), 57.7 (CH), 65.3
tetrahydro-1H-spiro[pyrido [2,1-a]isoindole-2,2 -[1,3]dithiolan]-10-
yl)urea 25
Compound 25 was obtained following the general procedure A
from the amine 8 and 1-methyl-1H-pyrazole-3-carboxylic acid af-
þ
ESI) calc. for C25
25
H N
4
O
3
S
2
[MþH] : 493.1368, found: 493.1384.
ter purification by flash chromatography (CH
2
Cl
2
/MeOH 99/1) as a
ꢀ
ꢁ1
yellow solid in 68% yield. m.p. 134e136 C. IR (ATR-Diamond, cm
)
)
1
7.1.19. cis-1-(2-Methoxy-6-oxo-1,2,3,4,6,10b-hexahydropyrido[2,1-
n
3256, 2923, 1676, 1530, 1485, 1287. H NMR (400 MHz, CDCl
3
a]isoindol-10-yl)-3-(4-methoxyquinolin-2-yl)urea 22
Compound 22 was prepared following the general procedure A
from the amine 9 and 4-methoxyquinoline-2-carboxylic acid after
d
1.62 (t, J ¼ 12.5 Hz,1H), 2.01 (td, J ¼ 5.0 Hz, J ¼ 12.5 Hz,1H), 2.17 (d,
J ¼ 12.5 Hz, 1H), 2.95 (d, J ¼ 13.5 Hz, 1H), 3.16e3.33 (m, 5H), 3.87 (s,
3H), 4.52 (dd, J ¼ 3.8 Hz, J ¼ 13.5 Hz, 1H), 4.81 (dd, J ¼ 3.1 Hz,
J ¼ 11.5 Hz,1H), 5.91 (s,1H), 7.23 (d, J ¼ 2.2 Hz,1H), 7.42 (t, J ¼ 7.7 Hz,
purification by flash chromatography (CH
white solid in 80% yield. m.p. >260 C. IR (ATR-Diamond, cm
2
Cl
2
/MeOH 99/1) as a
ꢀ
ꢁ1
)
n
1H), 7.61 (d, J ¼ 7.4 Hz,1H), 7.89 (d, J ¼ 8.0 Hz,1H), 8.82 (s, 1H),10.08
1
13
1694, 1610, 1556, 1479, 1416, 1338, 1295, 759. H NMR (400 MHz,
(s, 1H). C NMR (100 MHz, CDCl
3
)
d
38.4 (CH
2
), 38.8 (CH
2
), 38.9
DMSO-d
6
)
d
0.76 (q, J ¼ 12.5 Hz, 1H), 1.05e1.15 (m, 1H), 2.09 (d,
2 3 2 2
(CH ), 39.2 (CH ), 41.0 (CH ), 45.0 (CH ), 57.8 (CH), 65.8 (Cq), 94.6
(CH), 119.8 (CH), 126.3 (CH), 129.3 (CH), 131.4 (CH), 133.2 (Cq), 133.3
J ¼ 12.5 Hz, 1H), 2.82 (s, 3H), 2.91 (d, J ¼ 13.5 Hz, 1H), 3.15 (td,
J ¼ 3.2 Hz, J ¼ 13.5 Hz,1H), 3.59 (d, J ¼ 12.0 Hz,1H), 4.01 (s, 3H), 4.30
(Cq), 136.0 (Cq), 148.5 (Cq), 153.5 (Cq), 166.3 (Cq). HRMS (ESI) calc.
þ
(
6
7
1
dd, J ¼ 4.0 Hz, J ¼ 13.5 Hz, 1H), 4.92 (dd, J ¼ 3.2 Hz, J ¼ 12.0 Hz, 1H),
for C19
H
21
N
5
O
2
S
2
Na [MþNa] : 438.1034, found: 438.1025.
.84 (s, 1H), 7.41e7.51 (m, 3H), 7.77 (dd, J ¼ 7.5 Hz, J ¼ 8.0 Hz, 1H),
.92 (d, J ¼ 8.0 Hz, 1H), 8.02 (d, J ¼ 8.0 Hz, 1H), 8.29 (d, J ¼ 8.0 Hz,
7.1.23. cis-1-(2-Methoxy-6-oxo-1,2,3,4,6,10b-hexahydropyrido[2,1-
a]isoindol-10-yl)-3-(1-methyl-1H-pyrazol-3-yl)urea 26
1
3
H), 10.15 (s, 1H), 11.99 (s, 1H). C NMR (100 MHz, DMSO-d
6
)
d
30.8
(
(
(
(
(
CH
2
), 34.4 (CH ), 36.4 (CH ), 54.7 (CH ), 55.9 (CH), 56.0 (CH
2
2
3
3
), 76.4
Compound 26 was prepared following the general procedure A
from the amine 9 and 1-methyl-1H-pyrazole-3-carboxylic acid af-
CH), 91.9 (CH), 117.8 (CH), 118.1 (Cq), 121.5 (CH), 123.6 (CH), 124.1
CH), 126.3 (CH), 128.9 (CH), 130.7 (CH), 132.8 (Cq), 133.7 (Cq), 134.3
Cq), 145.6 (Cq), 152.3 (Cq), 153.8 (Cq), 162.9 (Cq), 164.6 (Cq). HRMS
ter purification by flash chromatography (CH
yellow solid in 81% yield. m.p. 196e198 C. IR (ATR-Diamond, cm
2
Cl
2
/MeOH 99/1) as a
ꢀ
ꢁ1
)
þ
1
ESI) calc. for C24
H
25
N
4
O
4
[MþH] : 433.1876, found: 433.1884.
n
1686, 1625, 1538, 1482e1421, 1316, 1284, 751. H NMR (400 MHz,
CDCl
3
)
d
1.06 (q, J ¼ 12.0 Hz, 1H), 1.27e1.39 (m, 1H), 2.21 (d,
7
1
.1.20. 1-(3-Methylpyridin-2-yl)-3-(6-oxo-3,4,6,10b-tetrahydro-
H-spiro[pyrido[2,1-a] isoindole-2,2 -[1,3]dioxolan]-10-yl)urea 23
Compound 23 was prepared following the general procedure A
J ¼ 12.0 Hz, 1H), 2.97e3.08 (m, 2H), 3.35 (s, 3H), 3.55e3.60 (m, 1H),
3.87 (s, 3H), 4.56e4.60 (m, 2H), 5.84 (s, 1H), 7.27 (d, J ¼ 2.2 Hz, 1H),
7.45 (dd, J ¼ 7.5 Hz, J ¼ 8.0 Hz, 1H), 7.62 (d, J ¼ 7.5 Hz, 1H), 7.98 (s,
0
1
3
from the amine 10 and 3-methylpicolinic acid after purification by
flash chromatography (CH
yield. m.p. >260 C. IR (ATR-Diamond, cm
1
1H), 8.04 (d, J ¼ 8.0 Hz, 1H), 10.06 (s, 1H). C NMR (100 MHz, CDCl
3
)
2
Cl
2
/MeOH 99/1) as a white solid in 72%
2 2 2 3 3
d 30.3 (CH ), 35.7 (CH ), 37.0 (CH ), 38.8 (CH ), 55.7 (CH ), 56.9
ꢀ
ꢁ1
)
n
1679, 1566,
1.35 (t,
(CH), 77.2 (CH), 94.1 (CH), 119.5 (CH), 125.0 (CH), 129.2 (CH), 131.5
1
480e1415, 1291, 1135. H NMR (400 MHz, DMSO-d
6
)
d
(CH), 133.2 (Cq), 133.3 (Cq), 135.2 (Cq), 148.2 (Cq), 152.8 (Cq), 166.0
þ
J ¼ 12.5 Hz, 1H), 1.53 (td, J ¼ 5.0 Hz, J ¼ 12.5 Hz, 1H), 1.86 (d,
J ¼ 12.5 Hz, 1H), 2.32 (s, 3H), 2.62 (d, J ¼ 12.5 Hz, 1H), 3.17 (td,
J ¼ 3.2 Hz, J ¼ 13.5 Hz, 1H), 3.81e4.07 (m, 4H), 4.30 (dd, J ¼ 3.2 Hz,
J ¼ 13.5 Hz, 1H), 4.84 (dd, J ¼ 3.3 Hz, J ¼ 12.5 Hz, 1H), 7.09 (dd,
J ¼ 7.0 Hz, J ¼ 8.0 Hz, 1H), 7.39e7.50 (m, 2H), 7.69 (d, J ¼ 7.0 Hz, 1H),
(Cq). HRMS (ESI) calc. for C18
378.1542.
H
21
N
5
O
3
Na [MþNa] : 378.1542, found:
7.1.24. 1-(5-Methylpyrazin-2-yl)-3-(6-oxo-3,4,6,10b-tetrahydro-
0
1H-spiro[pyrido[2,1-a] isoindole-2,2 -[1,3]dithiolan]-10-yl)urea 27
8
1
.23 (d, J ¼ 7.5 Hz, 1H), 8.33 (d, J ¼ 7.5 Hz, 1H), 8.85 (s, 1H), 12.4 (s,
Compound 27 was prepared following the general procedure A
from the amine 8 and 5-methylpyrazine-2-carboxylic acid after
13
H). C NMR (100 MHz, DMSO-d
6
)
d
17.5 (CH
3
) 34.4 (CH
2
), 36.4
(
(
(
(
CH
2
), 37.8 (CH ), 55.7 (CH), 64.3 (CH
2
2
), 64.6 (CH
2
), 107.4 (Cq), 110.8
purification by flash chromatography (CH
white solid in 85% yield. m.p. >260 C. IR (ATR-Diamond, cm
2
Cl
2
/MeOH 99/1) as a
ꢀ
ꢁ1
CH), 112.7 (CH), 117.5 (CH), 129.2 (CH), 133.0 (Cq), 134.6 (Cq), 137.2
CH), 143.3 (Cq), 143.9 (Cq), 145.5 (CH), 151.6 (Cq), 152.7 (Cq), 166.2
Cq). HRMS (ESI) calc. for C21
95.1731.
) n
1
2977, 1688, 1621, 1586, 1414, 1332, 1288, 753. H NMR (400 MHz,
DMSO-d
1.61 (t, J ¼ 12.2 Hz, 1H), 1.93 (td, J ¼ 5.0 Hz, J ¼ 12.2 Hz,
1H), 2.12 (d, J ¼ 12.5 Hz, 1H), 2.43 (s, 3H), 2.87 (d, J ¼ 12.5 Hz, 1H),
þ
23
H N
4
O
4
[MþH] : 395.1719, found:
6
) d
3
3
.14 (t, J ¼ 12.2 Hz, 1H), 3.29e3.35 (m, 3H), 3.39e3.44 (m, 1H), 4.32
7
.1.21. cis-1-(2-Methoxy-6-oxo-1,2,3,4,6,10b-hexahydropyrido[2,1-
(dd, J ¼ 2.8 Hz, J ¼ 12.2 Hz, 1H), 4.75 (dd, J ¼ 2.8 Hz, J ¼ 12.2 Hz, 1H),
a]isoindol-10-yl)-3-(3-methylpyridin-2-yl)urea 24
Compound 24 was prepared following the general procedure A
from the amine 9 and 3-methylpicolinic acid after purification by
7.42e7.50 (m, 2H), 8.06 (d, J ¼ 7.5 Hz, 1H), 8.27 (s, 1H), 8.73 (s, 1H),
1
3
10.04 (s, 2H). C NMR (100 MHz, DMSO-d
6
)
d
20.2 (CH
3 2
), 37.8 (CH ),
38.2 (CH ), 38.7 (CH ), 40.5 (CH ), 41.0 (CH ), 56.9 (CH), 65.6 (Cq),
2 2 2 2

284
R. Boulahjar et al. / European Journal of Medicinal Chemistry 101 (2015) 274e287
ꢀ
ꢁ1
n
1
18.2 (CH), 124.0 (CH), 129.1 (CH), 132.8 (Cq), 133.5 (Cq), 134.3 (CH),
yield. m.p. 240e242 C. IR (ATR-Diamond, cm
)
1700, 1551, 1481,
1.66 (t,
1
134.6 (Cq), 139.7 (CH), 146.0 (Cq), 146.9 (Cq), 151.8 (Cq), 164.7 (Cq).
1430, 1367, 1240, 1048, 759. H NMR (400 MHz, DMSO-d
6
)
d
þ
HRMS (ESI) calc. for C20
H
22
N
5
O
2
S
2
[MþH] : 428.1215, found:
J ¼ 12.0 Hz, 1H), 1.95 (td, J ¼ 5.0 Hz, J ¼ 13.0 Hz, 1H), 2.15 (d,
J ¼ 13.0 Hz, 1H), 2.92 (d, J ¼ 11.6 Hz, 1H), 3.17 (td, J ¼ 3.2 Hz,
J ¼ 13.3 Hz, 1H), 3.27e3.50 (m, 4H), 4.34 (dd, J ¼ 3.2 Hz, J ¼ 13.5 Hz,
1H), 4.78 (dd, J ¼ 3.3 Hz, J ¼ 11.6 Hz,1H), 7.33 (d, J ¼ 8.9 Hz,1H), 7.43
(d, J ¼ 6.8 Hz, 1H), 7.49 (t, J ¼ 7.8 Hz, 1H), 8.01 (dd, J ¼ 2.5 Hz,
J ¼ 8.9 Hz, 1H), 8.17 (d, J ¼ 7.8 Hz, 1H), 8.57 (d, J ¼ 2.4 Hz, 1H), 10.10
4
28.1229.
7.1.25. cis-1-(2-Methoxy-6-oxo-1,2,3,4,6,10b-hexahydropyrido[2,1-
a]isoindol-10-yl)-3-(5-methylpyrazin-2-yl)urea 28
Compound 28 was prepared following the general procedure A
from the amine 9 and 5-methylpyrazine-2-carboxylic acid after
13
(s, 1H), 10.69 (s, 1H). C NMR (100 MHz, DMSO-d
6 2
) d 37.7 (CH ),
purification by flash chromatography (CH
yellow solid in 76% yield. m.p. 140e142 C. IR (ATR-Diamond, cm
2
Cl
2
/MeOH 99/1) as a
38.2 (CH ), 38.8 (CH ), 40.7 (CH ), 44.0 (CH ), 56.9 (CH), 65.7 (Cq),
111.4 (Cq), 114.0 (CH), 118.0 (CH), 123.6 (CH), 129.1 (CH), 132.7 (Cq),
2
2
2
2
ꢀ
ꢁ1
)
1
n
1688, 1598, 1554, 1484, 1438, 1344, 1291, 753. H NMR (400 MHz,
CDCl
1.06 (q, J ¼ 12.0 Hz, 1H), 1.30e1.40 (m, 1H), 2.22 (d,
J ¼ 12.5 Hz, 1H), 2.54 (s, 3H), 2.96e3.06 (m, 2H), 3.38 (s, 3H),
.53e3.61 (m, 1H), 4.53e4.62 (m, 2H), 7.49 (dd, J ¼ 7.5 Hz,
J ¼ 8.0 Hz,1H), 7.66 (d, J ¼ 7.5 Hz,1H), 8.02 (s, 1H), 8.11 (d, J ¼ 8.0 Hz,
133.6 (Cq), 134.2 (Cq), 141.3 (CH), 147.1 (CH), 151.8 (2 Cq), 164.7 (Cq).
þ
3
)
d
HRMS (ESI) calc. for C20
513.0016.
H
19
N
4
O
2
S
2
BrNa [MþNa] : 513.0031, found:
3
7.1.29. General procedure B: preparation of the ketones 32e36
The chosen acetal (0.52 mmol) and a solution of hydrochloric
acid 10% (2 mL) in acetone (4 mL) was refluxed for 3 h. After cooling,
acetone was removed under reduced pressure. The resulting solid
was filtered, washed with water (2 mL) and dried to give the cor-
responding ketones.
1
3
1
H), 8.42 (s, 1H), 9.80 (s, 1H), 11.16 (s, 1H). C NMR (100 MHz,
CDCl 20.6 (CH ), 30.5 (CH ), 35.7 (CH ), 37.1 (CH ), 55.9 (CH ),
6.9 (CH), 77.3 (CH), 120.0 (CH), 124.6 (CH), 129.5 (CH), 132.6 (Cq),
3
)
d
3
2
2
2
3
5
133.3 (Cq), 135.0 (Cq), 135.1 (CH), 137.7 (CH), 146.6 (Cq), 146.7 (Cq),
þ
153.5 (Cq), 165.9 (Cq). HRMS (ESI) calc. for C19
22
H N
5
O
3
[MþH] :
3
68.1723, found: 368.1722.
7.1.30. 1-(2,6-Dioxo-1,2,3,4,6,10b-hexahydropyrido[2,1-a]isoindol-
7.1.26. cis-1-(2-Methoxy-6-oxo-1,2,3,4,6,10b-hexahydropyrido[2,1-
10-yl)-3-(pyridin-2-yl) urea 32
a]isoindol-10-yl)-3-(4-methylpyridin-2-yl)urea 29
Compound 29 was prepared following the general procedure A
from the amine 9 and 4-methylpicolinic acid after purification by
Compound 32 was obtained following the general procedure B
from compound 11 as a white solid in 98% yield. m.p. 253e255 C.
ꢀ
ꢁ
1
IR (ATR-Diamond, cm
)
n
1692, 1623, 1568, 1479, 1457, 1421, 1309,
1
flash chromatography (CH
yield. m.p. 218e220 C. IR (ATR-Diamond, cm
2
Cl
2
/MeOH 99/1) as a yellow solid in 76%
1243, 751. H NMR (400 MHz, DMSO-d
6
) d
2.34 (t, J ¼ 12.0 Hz, 1H),
ꢀ
ꢁ1
)
n
1690, 1619, 1573,
0.75 (q,
2.38e2.45 (m, 1H), 2.57e2.66 (m, 1H), 3.26 (dd, J ¼ 2.8 Hz,
J ¼ 13.0 Hz, 1H), 3.49 (td, J ¼ 4.4 Hz, J ¼ 12.6 Hz, 1H), 4.47e4.50 (m,
1H), 5.08 (dd, J ¼ 3.9 Hz, J ¼ 11.9 Hz, 1H), 7.10 (dd, J ¼ 5.4 Hz,
J ¼ 6.8 Hz, 1H), 7.30 (d, J ¼ 8.3 Hz,1H), 7.45 (d, J ¼ 6.8 Hz,1H), 7.51 (t,
J ¼ 7.7 Hz, 1H), 7.76e7.85 (m, 1H), 8.30 (d, J ¼ 8.3 Hz, 1H), 8.34e8.40
1
1481e1439,1310,1293, 752. H NMR (400 MHz, DMSO-d
6
)
d
J ¼ 12.0 Hz, 1H), 1.08e1.19 (m, 1H), 2.14 (d, J ¼ 12.0 Hz, 1H), 2.30 (s,
3
3
4
1
H), 2.99 (d, J ¼ 12.0 Hz, 1H), 3.10 (td, J ¼ 3.2 Hz, J ¼ 13.2 Hz, 1H),
.25 (s, 3H), 3.69e3.77 (m, 1H), 4.29 (dd, J ¼ 3.2 Hz, J ¼ 13.2 Hz, 1H),
.70 (dd, J ¼ 3.2 Hz, J ¼ 12.0 Hz, 1H), 6.92 (d, J ¼ 5.2 Hz, 1H), 7.08 (s,
H), 7.37 (d, J ¼ 7.5 Hz, 1H), 7.46 (dd, J ¼ 7.5 Hz, J ¼ 8.0 Hz, 1H), 8.20
13
6
(m, 1H), 9.99 (s, 1H), 11.26 (s, 1H). C NMR (100 MHz, DMSO-d )
d
2 2 2
36.6 (CH ), 39.0 (CH ), 44.0 (CH ), 56.0 (CH), 112.2 (CH), 117.5 (CH),
117.6 (CH), 122.7 (CH), 129.4 (CH), 132.5 (Cq), 133.7 (Cq), 134.0 (Cq),
(
d, J ¼ 5.2 Hz, 1H), 8.26 (d, J ¼ 8.0 Hz, 1H), 9.86 (s, 1H), 11.43 (s, 1H).
1
3
C NMR (100 MHz, DMSO-d
6.5 (CH ), 55.2 (CH ), 55.8 (CH), 76.3 (CH), 112.1 (CH), 117.4 (CH),
18.8 (CH), 122.2 (CH), 129.1 (CH), 132.7 (Cq), 133.9 (Cq), 134.0 (Cq),
6
)
d
20.8 (CH
3
), 30.7 (CH
2
), 35.2 (CH
2
),
139.1 (CH), 146.2 (CH), 152.1 (Cq), 152.8 (Cq), 165.3 (Cq), 206.3 (Cq).
þ
3
1
2
3
HRMS (ESI) calc. for
337.1294.
C
18
H
17
N
4
O
3
[MþH] : 337.1301, found:
1
45.6 (CH), 150.0 (Cq), 152.2 (Cq), 152.9 (Cq), 164.7 (Cq). HRMS (ESI)
þ
calc. for C20
23
H N
4
O
3
[MþH] : 367.1770, found: 367.1761.
7.1.31. 1-(2,6-Dioxo-1,2,3,4,6,10b-hexahydropyrido[2,1-a]isoindol-
0-yl)-3-(pyrazin-2-yl) urea 33
1
7
.1.27. (6-Bromopyridin-2-yl)-3-(6-oxo-3,4,6,10b-tetrahydro-1H-
Compound 33 was obtained following the general procedure B
from compound 14 as beige solid in 95% yield. m.p. >260 C. IR
0
ꢀ
spiro[pyrido[2,1-a]isoin-dole-2,2 -[1,3]dithiolan]-10-yl)urea 30
Compound 30 was obtained following the general procedure A
from the amine 8 and 6-bromopicolinic acid after purification by
flash chromatography (CH
yield. m.p. 168e170 C. IR (ATR-Diamond, cm
ꢁ
1
(ATR-Diamond, cm
)
n
1689, 1660, 1569, 1502, 1477, 1430, 1304,
1
1143, 1065. H NMR (400 MHz, DMSO-d
6
) d
2.31 (dd, J ¼ 2.7 Hz,
2
Cl
2
/MeOH 99/1) as a yellow solid in 57%
J ¼ 13.5 Hz, 1H), 2.37e2.44 (m, 1H), 2.57e2.67 (m, 1H), 3.17 (dd,
J ¼ 2.7 Hz, J ¼ 13.5 Hz, 1H), 3.48 (td, J ¼ 4.4 Hz, J ¼ 12.8 Hz, 1H),
4.44e4.49 (m, 1H), 5.05 (dd, J ¼ 3.9 Hz, J ¼ 11.9 Hz, 1H), 7.48 (dd,
J ¼ 1.2 Hz, J ¼ 7.7 Hz, 1H), 7.53 (t, J ¼ 7.7 Hz, 1H), 8.18 (dd, J ¼ 0.9 Hz,
J ¼ 7.5 Hz, 1H), 8.32 (d, J ¼ 2.7 Hz, 1H), 8.35e8.37 (m, 1H), 8.90 (d,
ꢀ
ꢁ1
) n 1654, 1565, 1530,
1
1486,1430, 786. H NMR (400 MHz, CDCl
3
)
d
1.66 (t, J ¼ 12.0 Hz,1H),
2
.03 (td, J ¼ 5.0 Hz, J ¼ 13.4, 1H), 2.18 (d, J ¼ 13.5 Hz, 1H), 2.85 (dd,
J ¼ 1.9 Hz, J ¼ 10.0 Hz, 1H), 3.09e3.38 (m, 5H), 4.55 (dd, J ¼ 3.7 Hz,
J ¼ 13.8 Hz, 1H), 4.97 (dd, J ¼ 3.3 Hz, J ¼ 11.5 Hz, 1H), 7.14 (d,
J ¼ 7.7 Hz, 2H), 7.51 (td, J ¼ 5.7 Hz, J ¼ 7.8 Hz, 2H), 7.72 (dd, J ¼ 7.6 Hz,
13
J ¼ 1.2 Hz, 1H), 9.86 (s, 1H), 10.12 (s, 1H). C NMR (100 MHz, DMSO-
6 2 2 2
d ) d 36.6 (CH ), 39.0 (CH ), 43.9 (CH ), 56.0 (CH), 118.1 (CH), 123.4
13
J ¼ 13.4 Hz, 2H), 9.91 (s, 1H), 10.88 (s, 1H). C NMR (100 MHz,
(CH), 129.4 (CH), 132.6 (Cq), 133.5 (Cq), 134.4 (Cq), 135.5 (CH), 137.9
CDCl
8.3 (CH), 65.6 (Cq), 111.2 (CH), 121.0 (CH), 121.4 (CH), 127.3 (CH),
29.4 (CH), 132.4 (Cq), 133.7 (Cq), 137.3 (Cq), 138.3 (Cq), 140.9 (CH),
3
)
d
38.6 (CH
2
), 38.9 (CH
2
), 39.1 (CH
2
2
), 41.0 (CH ), 45.2 (CH
2
),
(CH), 141.0 (CH), 149.1 (Cq), 151.7 (Cq), 165.2 (Cq), 206.3 (Cq). HRMS
þ
5
1
(ESI) calc. for C17
H
15
N
5
O
3
Na [MþNa] : 360.1073, found: 360.1078.
1
C
53.1 (Cq), 153.6 (Cq), 166.1 (Cq). HRMS (ESI) calc. for
7.1.32. 1-(2,6-Dioxo-1,2,3,4,6,10b-hexahydropyrido[2,1-a]isoindol-
10-yl)-3-(6-methyl-pyridin-2-yl)urea 34
þ
H
20 19
N
4
O
S
2 2
BrNa [MþNa] : 513.0031, found: 513.0014.
Compound 34 was obtained following the general procedure B
ꢀ
7.1.28. (5-Bromopyridin-2-yl)-3-(6-oxo-3,4,6,10b-tetrahydro-1H-
from compound 17 as white solid in 79% yield. m.p. 226e228 C. IR
0
ꢁ1
spiro[pyrido[2,1-a]isoin-dole-2,2 -[1,3]dithiolan]-10-yl)urea 31
Compound 31 was obtained following the general procedure A
from the amine 8 and 5-bromopicolinic acid after purification by
(ATR-Diamond, cm
) n 1683, 1621, 1566, 1467e1435, 1323, 1287,
1
752. H NMR (400 MHz, DMSO-d
6
)
d
2.37 (t, J ¼ 12.5 Hz, 1H), 2.44 (s,
3H), 2.54e2.68 (m, 1H), 3.11 (dd, J ¼ 2.5 Hz, J ¼ 12.8 Hz, 1H), 3.17 (d,
2 2
flash chromatography (CH Cl /MeOH 99/1) as a yellow solid in 82%
J ¼ 5.0 Hz, 1H), 3.45 (td, J ¼ 5.0 Hz, J ¼ 12.8 Hz, 1H), 4.48 (dd,

R. Boulahjar et al. / European Journal of Medicinal Chemistry 101 (2015) 274e287
285
J ¼ 2.8 Hz, J ¼ 12.5 Hz, 1H), 5.08 (dd, J ¼ 2.8 Hz, J ¼ 12.5 Hz, 1H), 6.91
J ¼ 7.7 Hz, 1H), 8.32 (d, J ¼ 4.5 Hz, 1H), 9.96 (s, 1H), 11.21 (s, 1H). 13C
(
(
d, J ¼ 7.5 Hz, 1H), 7.17 (d, J ¼ 8.0 Hz, 1H), 7.45e7.55 (m, 2H), 7.66
dd, J ¼ 7.5 Hz, J ¼ 8.0 Hz, 1H), 8.18 (d, J ¼ 7.5 Hz, 1H), 9.84 (s, 1H),
6 2 2 2
NMR (100 MHz, DMSO-d ) d 34.5 (CH ), 36.6 (CH ), 38.7 (CH ), 56.0
(CH), 66.7 (CH), 112.1 (CH), 117.5 (CH), 117.6 (CH), 122.6 (CH), 128.9
(CH), 132.7 (Cq), 133.8 (Cq), 134.4 (Cq), 139.1 (CH), 146.2 (CH), 152.1
1
0.70 (s, 1H). 13C NMR (100 MHz, DMSO-d
) d 23.6 (CH ), 36.6 (CH ),
6 3 2
3
9.0 (CH
2
), 43.7 (CH
2
), 56.1 (CH), 109.0 (CH), 116.9 (CH), 118.0 (CH),
(Cq), 152.8 (Cq), 164.7 (Cq). HRMS (ESI) calc. for C18
[MþH] : 339.1457, found: 339.1462.
H
19
N
4
O
3
þ
123.9 (CH), 129.3 (CH), 132.5 (Cq), 133.8 (Cq), 134.4 (Cq), 139.2 (CH),
152.1 (Cq), 152.3 (Cq), 155.5 (Cq), 165.3 (Cq), 206.4 (Cq). HRMS (ESI)
þ
calc. for C19
H
19
N
4
O
3
[MþH] : 351.1452, found: 351.1451.
7.1.37. cis-1-(2-Hydroxy-6-oxo-1,2,3,4,6,10b-hexahydropyrido[2,1-
a]isoindol-10-yl)-3-(pyrazin-2-yl)urea 38
Compound 38 was obtained following the general procedure C
from compound 33 after purification by flash chromatography
7
.1.33. 1-(2,6-Dioxo-1,2,3,4,6,10b-hexahydropyrido[2,1-a]isoindol-
10-yl)-3-(4-methoxy-quinolin-2-yl)urea 35
Compound 35 was obtained following the general procedure B
ꢀ
ꢀ
(CH
2
Cl
2
/MeOH 96/4) as a white solid in 60% yield. m.p. 250e252 C.
from compound 20 as white solid in 83% yield. m.p. 223e225 C. IR
ꢁ1
ꢁ1
IR (ATR-Diamond, cm
)
n
1694, 1671, 1622, 1568, 1545, 1500, 1485,
1427,1296,1056. H NMR (400 MHz, DMSO-d
0.75 (q, J ¼ 11.8 Hz,
H), 1.14e1.23 (m, 1H), 1.94 (d, J ¼ 12.1 Hz, 1H), 2.78 (d, J ¼ 11.8 Hz,
H), 3.07 (td, J ¼ 3.1 Hz, J ¼ 13.2 Hz, 1H), 3.88e3.95 (m, 1H), 4.25
(
ATR-Diamond, cm
)
n
2976, 1683, 1621, 1558, 1469, 1435, 1329,
1
1
6
) d
1
2
3
289, 751. H NMR (400 MHz, DMSO-d
6
)
d
2.29 (t, J ¼ 12.5 Hz, 1H),
1
1
.41 (d, J ¼ 12.5 Hz, 1H), 2.53e2.62 (m, 1H), 3.20 (d, J ¼ 12.8 Hz, 1H),
.50 (td, J ¼ 2.5 Hz, J ¼ 12.8 Hz, 1H), 4.13 (s, 3H), 4.44 (dd, J ¼ 2.8 Hz,
(
5
dd, J ¼ 3.9 Hz, J ¼ 13.2 Hz, 1H), 4.65 (dd, J ¼ 3.1 Hz, J ¼ 11.8 Hz, 1H),
J ¼ 12.8 Hz, 1H), 5.18 (dd, J ¼ 2.8 Hz, J ¼ 12.5 Hz, 1H), 7.02 (s, 1H),
.01 (d, J ¼ 4.9 Hz, 1H), 7.42 (dd, J ¼ 0.8 Hz, J ¼ 7.4 Hz, 1H), 7.48 (t,
7
3
.55e7.59 (m, 3H), 7.82 (dd, J ¼ 7.5 Hz, J ¼ 8.0 Hz, 1H), 8.00e8.11 (m,
13
J ¼ 7.7 Hz, 1H), 8.10 (dd, J ¼ 0.6 Hz, J ¼ 7.7 Hz, 1H), 8.31 (d, J ¼ 2.7 Hz,
H), 10.99 (s, 1H), 11.32 (s, 1H). C NMR (100 MHz, DMSO-d
6
) d 36.5
1
1
H), 8.32e8.38 (m, 1H), 8.94 (d, J ¼ 1.2 Hz, 1H), 9.85 (s, 1H), 10.08 (s,
(
(
(
CH
2
), 39.0 (CH ), 43.6 (CH ), 56.1 (CH ), 57.1 (CH), 92.1 (CH), 117.6
2
2
3
13
H). C NMR (100 MHz, DMSO-d
), 56.0 (CH), 66.7 (CH), 118.1 (CH), 123.3 (CH), 129.0 (CH), 132.8
Cq), 133.4 (Cq), 135.0 (Cq), 135.4 (CH), 137.9 (CH), 141.1 (CH), 149.2
6 2 2
) d 34.4 (CH ), 36.6 (CH ), 38.7
Cq), 119.0 (CH), 122.0 (CH), 122.8 (Cq), 124.9 (CH), 125.6 (CH), 129.4
(CH
2
2 ꢂ CH), 132.4 (CH), 132.7 (Cq), 132.8 (Cq), 135.8 (Cq), 152.0 (Cq),
(
1
52.3 (Cq), 165.1 (Cq), 165.3 (Cq), 205.7 (Cq). HRMS (ESI) calc. for
þ
(Cq), 151.7 (Cq), 164.6 (Cq). HRMS (ESI) calc. for C17
H
17
N
5
O
3
Na
C
23 21
H N
4
O
4
[MþH] : 417.1563, found: 417.1571.
þ
[
MþNa] : 362.1229, found: 362.1223.
7.1.34. 1-(2,6-Dioxo-1,2,3,4,6,10b-hexahydropyrido[2,1-a]isoindol-
1
0-yl)-3-(3-methyl-pyridin-2-yl)urea 36
Compound 36 was obtained following the general procedure B
7
.1.38. cis-1-(2-Hydroxy-6-oxo-1,2,3,4,6,10b-hexahydropyrido[2,1-
a]isoindol-10-yl)-3-(6-methylpyridin-2-yl)urea 39
ꢀ
from compound 23 as white solid in 85% yield. m.p. >260 C. IR
Compound 39 was obtained following the general procedure C
ꢁ1
(
1
2
ATR-Diamond, cm
)
n
1684, 1621, 1559, 1479, 1434, 1414, 1329,
289, 751. H NMR (400 MHz, DMSO-d
2.22 (t, J ¼ 12.5 Hz, 1H),
.40 (d, J ¼ 12.8 Hz, 1H), 2.49e2.60 (m, 4H), 3.33e3.38 (m, 1H), 3.47
from compound 34 after purification by flash chromatography
1
6
)
d
ꢀ
(CH
2
Cl
2
/MeOH 99/1) as a white solid in 80% yield. m.p. 240e242 C.
ꢁ1
IR (ATR-Diamond, cm
)
n
3143, 1685, 1589, 1508, 1484, 1424, 1270.
0.76 (q, J ¼ 12.5 Hz, 1H), 1.11e1.25
m, 1H), 1.94 (d, J ¼ 12.5 Hz, 1H), 2.51 (s, 3H), 2.76 (d, J ¼ 12.5 Hz,
H), 3.07 (td, J ¼ 2.5 Hz, J ¼ 12.8 Hz, 1H), 3.82e3.93 (m, 1H), 4.26
dd, J ¼ 2.8 Hz, J ¼ 12.2 Hz, 1H), 4.71 (dd, J ¼ 2.8 Hz, J ¼ 12.2 Hz, 1H),
.01 (d, J ¼ 5.0 Hz,1H), 6.93 (d, J ¼ 7.5 Hz,1H), 7.16 (d, J ¼ 8.2 Hz,1H),
(
td, J ¼ 2.5 Hz, J ¼ 12.8 Hz, 1H), 4.40e4.46 (m, 1H), 5.20 (dd,
1
6
H NMR (400 MHz, DMSO-d ) d
J ¼ 2.5 Hz, J ¼ 12.5 Hz, 1H), 7.36 (dd, J ¼ 5.2 Hz, J ¼ 7.5 Hz, 1H),
(
1
(
5
7
.52e7.58 (m, 2H), 8.04 (d, J ¼ 7.5 Hz, 1H), 8.16 (d, J ¼ 7.5 Hz, 1H),
1
3
8
.28 (d, J ¼ 5.2 Hz, 1H), 10.91 (s, 1H), 11.49 (s, 1H). C NMR
17.9 (CH ), 36.9 (CH ), 39.4 (CH ), 44.1 (CH ),
6.6 (CH), 118.8 (CH), 119.5 (CH), 124.7 (CH), 125.3 (Cq), 129.9 (CH),
(
100 MHz, DMSO-d
6
)
d
3
2
2
2
5
7
.39e7.51 (m, 2H), 7.67 (dd, J ¼ 7.5 Hz, J ¼ 8.2 Hz, 1H), 8.17 (d,
132.9 (Cq), 133.3 (Cq), 136.1 (Cq), 137.1 (CH), 145.5 (CH), 148.4 (Cq),
13
J ¼ 7.5 Hz, 1H), 9.84 (s, 1H), 10.75 (s, 1H). C NMR (100 MHz, DMSO-
153.2 (Cq), 165.5 (Cq), 206.3 (Cq). HRMS (ESI) calc. for C19
H
19
N
4
O
3
6 3 2 2 2
d ) d 23.8 (CH ), 34.4 (CH ), 36.6 (CH ), 38.4 (CH ), 56.1 (CH), 66.8
þ
[MþH] : 351.1452, found: 351.1451.
(
(
(
CH), 108.9 (CH), 116.8 (CH), 117.7 (CH), 123.6 (CH), 128.8 (CH), 132.7
Cq), 133.7 (Cq), 134.7 (Cq), 139.1 (CH), 152.2 (Cq), 152.3 (Cq), 155.4
Cq),164.7 (Cq). HRMS (ESI) calc. for C19
7
.1.35. General procedure C: synthesis of alcohols 37e41
þ
H
21
N
4
O
3
[MþH] : 353.1614,
ꢀ
At ꢁ20 C, to a solution of ketone (0.2 mmol) in a mixture THF/
found: 353.1619.
MeOH 1/2 (6 mL) was added portion wise NaBH
4
(15 mg, 0.4 mmol,
2
.0 eq.). The mixture was stirred at this temperature for 30 min and
ꢀ
the temperature was then allowed to rise to 0e5 C for 2 h. Water
10 mL) was added, and the aqueous phase was extracted first with
CH Cl
7.1.39. cis-1-(2-Hydroxy-6-oxo-1,2,3,4,6,10b-hexahydropyrido[2,1-
a]isoindol-10-yl)-3-(4-methoxyquinolin-2-yl)urea 40
Compound 40 was obtained following the general procedure C
from compound 35 after purification by flash chromatography
(
2
2
(2 ꢂ 10 mL) and then with EtOAc (2 ꢂ 10 mL). The combined
organic layers were dried over MgSO
under reduced pressure.
4
, filtered and concentrated
ꢀ
(CH
ATR-Diamond, cm
6
NMR (250 MHz, DMSO-d ) d
2
Cl
2
/MeOH 99/1) as a white solid in 82% yield. m.p. >260 C. IR
ꢁ1
1
(
)
n
2977, 1686, 1585, 1512, 1479, 1414, 1289. H
0.76 (q, J ¼ 12.5 Hz, 1H), 1.04e1.21 (m,
7.1.36. cis-1-(2-Hydroxy-6-oxo-1,2,3,4,6,10b-hexahydropyrido[2,1-
a]isoindol-10-yl)-3-(pyridin-2-yl)urea 37
Compound 37 was obtained following the general procedure C
from compound 32 after purification by flash chromatography
1H), 1.93 (d, J ¼ 12.5 Hz, 1H), 2.79 (d, J ¼ 12.5 Hz, 1H), 3.14 (td,
J ¼ 2.8 Hz, J ¼ 12.5 Hz, 1H), 3.77e3.90 (m, 1H), 4.02 (s, 3H), 4.26 (dd,
J ¼ 2.8 Hz, J ¼ 12.5 Hz, 1H), 4.82e4.91 (m, 2H), 6.87 (s, 1H),
7.42e7.53 (m, 3H), 7.73 (dd, J ¼ 7.5 Hz, J ¼ 8.0 Hz, 1H), 7.88 (d,
ꢀ
(
CH
IR (ATR-Diamond, cm
309. 1H NMR (400 MHz, DMSO-d
2
Cl
2
/MeOH 93/7) as a white solid in 76% yield. m.p. 218e220 C.
ꢁ
1
)
n
3217, 1695, 1562, 1512e1478e1430,
0.77 (q, J ¼ 12.0 Hz, 1H),
J ¼ 8.0 Hz, 1H), 8.03 (d, J ¼ 8.0 Hz, 1H), 8.21 (d, J ¼ 7.5 Hz, 1H), 10.16
13
1
6
)
d
(s, 1H), 11.95 (s, 1H). C NMR (63 MHz, DMSO-d
6
)
d
34.5 (CH
2
), 36.6
1
3
1
.10e1.28 (m, 1H), 1.95 (d, J ¼ 11.7 Hz, 1H), 2.89 (d, J ¼ 11.7 Hz, 1H),
2 2 3
(CH ), 38.1 (CH ), 56.1 (CH ), 56.2 (CH), 66.7 (CH), 91.9 (CH), 117.9
(CH), 118.1 (Cq), 121.4 (CH), 123.8 (CH), 124.0 (CH), 126.1 (CH), 128.9
(CH), 130.8 (CH), 132.8 (Cq), 133.5 (Cq), 135.0 (Cq), 145.7 (Cq), 152.3
.08 (td, J ¼ 4.1 Hz, J ¼ 12.0 Hz, 1H), 3.60 (s, 1H), 3.96 (t, J ¼ 10.7 Hz,
H), 4.24 (dd, J ¼ 4.1 Hz, J ¼ 13.2 Hz, 1H), 4.69 (dd, J ¼ 2.8 Hz,
J ¼ 11.8 Hz, 1H), 7.04e7.13 (m, 1H), 7.33 (d, J ¼ 8.4 Hz, 1H), 7.38 (d,
(Cq), 153.7 (Cq), 163.0 (Cq), 164.7 (Cq). HRMS (ESI) calc. for
þ
J ¼ 7.3 Hz, 1H), 7.46 (t, J ¼ 7.7 Hz, 1H), 7.81 (t, J ¼ 7.3 Hz, 1H), 8.21 (d,
C
23
H
23
N
4
O
4
[MþH] : 419.1719, found: 419.1728.

286
R. Boulahjar et al. / European Journal of Medicinal Chemistry 101 (2015) 274e287
7
.1.40. cis-1-(2-Hydroxy-6-oxo-1,2,3,4,6,10b-hexahydropyrido[2,1-
update 3 [15] with Maestro, the interface piloting the diverse
modules. Glide was used to dock ligands. Analysis and visualization
tasks were performed with MOE software [16].
a]isoindol-10-yl)-3-(3-methylpyridin-2-yl)urea 41
Compound 41 was obtained following the general procedure C
from compound 36 after purification by flash chromatography
Structure preparation: crystal structures were retrieved from
the protein data bank: GSK3b with the PDB code 1J1B [17], CDK5
with the PDB code 4AU8 [18] and DYRK1A with the PDB code 4MQ1
[19]. Subunit A was conserved regarding the three structures which
were next prepared using the Protein Preparation Wizard workflow
of the Schrodinger Molecular Modelling Suite. Proteins were pre-
processed (hydrogen atoms added, incomplete residues filled),
bond orders and connections of ligands were manually corrected.
An exhaustive sampling was conducted regarding hydrogen bond
assignment and the complex was finally refined by a minimization
stage with a constraint to converge to a structure with an RMSD of
0.3 _A (OPLS2005 force field), essentially in order to remove steric
clashes. Ligands, other than the one cocrystallized, were built
within Marvin Sketch 5.8.0 [20] and were submitted to Corina [21],
a 3D structure generator. Next 3D structures were submitted to the
LigPrep module of the Schrodinger Molecular Modelling Suite in
order to take into account tautomerization and ionization via the
Epik module. The resulting structures became the starting point for
docking simulations. Docking parameters: docking calculations
were performed with extra precision. Ligand flexibility was taken
into account and the option of sampling of ring conformation was
activated.
ꢀ
(
CH
2
Cl
2
/MeOH 99/1) as a white solid in 82% yield. m.p. 204e206 C.
ꢁ1
IR (ATR-Diamond, cm
)
n
2960, 1684, 1584, 1503, 1486e1420,
262. H NMR (400 MHz, DMSO-d
0.80 (q, J ¼ 12.5 Hz, 1H),
.12e1.23 (m, 1H), 1.97 (d, J ¼ 12.5 Hz, 1H), 2.32 (s, 3H), 2.90 (d,
J ¼ 12.5 Hz, 1H), 3.08 (td, J ¼ 2.5 Hz, J ¼ 12.8 Hz, 1H), 3.95e4.02 (m,
1
1
1
6
) d
1
H), 4.25 (dd, J ¼ 2.8 Hz, J ¼ 12.2 Hz, 1H), 4.70 (dd, J ¼ 2.8 Hz,
J ¼ 12.2 Hz, 1H), 5.01 (d, J ¼ 5.0 Hz, 1H), 7.06 (dd, J ¼ 7.5 Hz,
J ¼ 8.0 Hz, 1H), 7.37 (d, J ¼ 7.5 Hz, 1H), 7.47 (dd, J ¼ 7.5 Hz, J ¼ 8.0 Hz,
1
H), 7.67 (d, J ¼ 7.5 Hz, 1H), 8.22 (d, J ¼ 7.5 Hz, 1H), 8.27 (d,
13
J ¼ 8.0 Hz,1H), 8.87 (s, 1H), 12.32 (s, 1H). C NMR (100 MHz, DMSO-
d
6
)
d
17.4 (CH ), 31.1 (CH ), 35.0 (CH ), 37.1 (CH ), 56.5 (CH), 67.2
3
2
2
2
(
(
(
CH), 117.9 (CH), 118.3 (CH), 121.8 (Cq), 123.0 (CH), 129.5 (CH), 133.2
Cq), 134.3 (Cq), 134.8 (Cq), 140.6 (CH), 143.5 (CH), 151.6 (Cq), 152.8
þ
Cq),165.2 (Cq). HRMS (ESI) calc. for C19
H
21
N
4
O
3
[MþH] : 353.1614,
found: 353.1616.
7.2. Kinase assay
ꢀ
Kinase activities were assayed in Buffer A or C, at 30 C, at a final
ATP concentration of 15
mM. Blank values were subtracted and
activities expressed in % of the maximal activity, i.e. in the absence
of inhibitors. Controls were performed with appropriate dilutions
of DMSO. The kinase peptide substrates were obtained from Pro-
teogenix (Oberhausbergen, France).
Acknowledgements
DYRK1A (human, recombinant, expressed in E. coli as a GST
fusion protein) was purified by affinity chromatography on
glutathione-agarose and assayed in buffer A (þ0.5 mg BSA/mL)
The authors thank the CNRS valorization service (A.O. retribu-
tion), Canc eꢀ rop o^ le Grand Ouest axis “Valorisation des produits de la
mer”, Association pour la Recherche contre le Cancer, the Program
Hubert Curien “Volubilis”, and the “Ligue Nationale contre le Can-
cer (Comit eꢀ Grand-Ouest)” for financial support.
using Woodtide (KKISGRLSPIMTEQ) (1.5 mg/assay) as a substrate, in
3
3
the presence of 15
mM [
g-
P] ATP (3000 Ci/mmol; 10 mCi/mL) in a
ꢀ
final volume of 30
ml. After 30 min incubation at 30 C, the reaction
was stopped by harvesting onto P81 phosphocellulose papers
Whatman) using a FilterMate harvester (Packard) and filters were
Appendix A. Supplementary data
(
washed in 1% phosphoric acid. Scintillation fluid was added and the
radioactivity measured in a Packard counter. CDK5/p25 (human,
recombinant) was prepared as previously described [13]. Its kinase
Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.ejmech.2015.06.046.
activity was assayed in buffer B, with 1 mg histone H1/mL. GSK-3
a/
References
b
(porcine brain, native) was assayed in Buffer A using a GSK3
specific substrate (GS-1: RRAAVPPSPSLSRHSSPH QSpEDEEE) (pS
stands for phosphorylated serine) [14].
[1] V. Tell, A. Hilgeroth, Recent developments of protein kinase inhibitors as
potential AD therapeutics, Front. Cell. Neurosci. 189 (2013) 1e8.
[
2] Z.L. Chen, V. Haegeli, H. Yu, S. Strickland, Cortical deficiency of laminin
gamma1 impairs the AKT/GSK-3beta signaling pathway and leads to defects in
neurite outgrowth and neuronal migration, Dev. Biol. 327 (2009) 158e168;
G. Paglini, A. C aꢀ ceres, Eur. J. Biochem. 268 (2001) 1528e1533;
7.3. Cell culture and survival assay
M. Mapelli, L. Massimiliano, C. Crovace, M.A. Seeliger, L.H. Tsai, L. Meijer,
A. Musacchio, Mechanism of CDK5/p25 binding by CDK inhibitors, J. Med.
Chem. 48 (2005) 671e679;
R.S. Jope, C.J. Yuskaitis, E. Beurel, Glycogen synthase kinase-3 (GSK3):
inflammation, diseases, and therapeutics, Neurochem. Res. 32 (2007)
HuH7, CaCo-2, MDA-MB-231, HCT116, PC3, HaCaT and NCI-H727
cell lines were obtained from the ECACC collection. Skin diploid
fibroblastic cells were provided by BIOPREDIC International Com-
pany (Rennes, France). Cells were grown according to ECACC rec-
ommendations. The toxicity test of the compounds on these cells
was as follows: 2.103 cells/well for HCT116 cell line or 4.103 cells/
well for the other cell lines were seeded in 96 well plates. 24 h after
cell seeding, cells were exposed to increasing concentrations of the
577e595.
[
3] J. Park, K.C. Chung, New perspectives of Dyrk1A role in neurogenesis and
neuropathologic features of Down syndrome, Exp. Neurobiol. 22 (2013)
244e248;
W. Becker, U. Soppa, F.J. Tejedor, DYRK1A: a potential drug target for multiple
Down syndrome neuropathologies, CNS Neurol. Disord. Drug Targets 13
(2014) 26e33.
compounds (0.1
mMe0.3 mMe0.9 mMe2.7 mMe8.3 mMe25 mM).
After 48 h of treatment, the cells were washed in PBS and fixed in
cooled 90% ethanol/5% acetic acid for 20 min. Then, the nuclei were
stained with Hoechst 3342 (Sigma). Image acquisition and analysis
was performed using a Cellomics ArrayScan VTI/HCS Reader
[4] J.R. Sundaram, C.P. Poore, N.H. Sulaimee, T. Pareek, A.B. Asad, R. Rajkumar,
W.F. Cheong, M.R. Wenk, G.S. Dawe, K.H. Chuang, H.C. Pant, S. Kesavapany,
Specific inhibition of p25/Cdk5 activity by the Cdk5 inhibitory peptide reduces
neurodegeneration in vivo, J. Neurosci. 33 (2013) 334e343;
X. Zhou, J. Zhou, X. Li, C. Guo, T. Fang, Z. Chen, GSK-3b inhibitors suppressed
neuroinflammation in rat cortex by activating autophagy in ischemic brain
injury, Biochem. Biophys. Res. Commun. 411 (2011) 271e275;
(
Thermo Scientific). The Ic50 were determined using Xlfit software.
E. Utreras, R. Hamada, M. Prochazkova, A. Terse, S. Takahashi, T. Ohshima,
A.B. Kulkarni, Suppression of neuroinflammation in forebrain-specific Cdk5
conditional knockout mice by PPARg agonist improves neuronal loss and early
7.4. Molecular modelling
lethality, J. Neuroinflammation 11 (2014) 28;
S. Jayapalan, J. Natarajan, The role of CDK5 and GSK3
Hardware and software: molecular modelling studies were
b kinases in hyper-
performed with the Schrodinger Molecular Modelling Suite 2014
phosphorylation of microtubule associated protein tau (MAPT) in Alzheimer's

R. Boulahjar et al. / European Journal of Medicinal Chemistry 101 (2015) 274e287
287
disease, Bioinformation 27 (2013) 1023e1030.
5] G. Li, T. Liu, X. Kong, L. Wang, X. Jin, Hippocampal glycogen synthase kinase 3b
is critical for the antidepressant effect of cyclin-dependent kinase 5 inhibitor
in rats, J. Mol. Neurosci. 54 (2014) 92e99.
6] J. Miranda-Barrientos, E. Nieto-Mendoza, E. Hern aꢀ ndez-Echeagaray, The Cdk5
S. Marionneau-Lambot, T. Oullier, O. Lozach, L. Meijer, C. Guguen-Guillouzo,
S. Lazar, M. Akssira, Y. Troin, G. Guillaumet, S. Routier, Novel tetrahydropyrido
[1,2-a]isoindolone derivatives (valmerins): potent cyclin-dependent kinase/
glycogen synthase kinase 3 inhibitors with antiproliferative activities and
antitumor effects in human tumor xenografts, J. Med. Chem. 55 (2012)
9589e9606.
[
[
inhibitor roscovitine increases LTP induction in corticostriatal synapses, ASN
Neuro 6 (2014) e00140;
H. Nehm eꢀ , R. Nehm eꢀ , P. Lafite, S. Routier, Ph. Morin, Human protein kinase
[10] M. Caballero, M. Garcia-Valverde, R. Pedrosa, M. Vicente, Elimination versus
diastereoselective alkylation in homochiral 2-(b-ethoxycarbonyl) acetals,
inhibitor screening by capillary electrophoresis using transverse diffusion of
Tetrahedron Asymmetry 7 (1996) 219e226.
laminar flow profiles for reactant mixing, J. Chromatogr. A 1314 (2013)
[11] A.-E. Alsarabi, J.L. Canet, Y. Troin, Short diastereoselective synthesis of cis- and
trans-hexahydropyrido[2,1-a]isoindole derivatives, Tetrahedron Lett. 45
(2004) 9003e9006.
298e305.
[
[
7] E.W. Kuehn, G. Walz, Prime time for polycystic kidney disease: does one shot
of roscovitine bring the cure? Nephrol. Dial. Transpl. 22 (2007) 2133e2135;
M. Gallorini, A. Cataldi, V.I. Giacomo, Cyclin-dependent kinase modulators and
cancer therapy, BioDrugs 26 (2012) 377e391.
[12] B.R. Huck, S.H. Gellman, Synthesis of 2,2-disubstituted pyrrolidine-4-
carboxylic acid derivatives and their incorporation into b-peptide oligomers,
J. Org. Chem. 70 (2005) 3353e3362.
[13] S. Leclerc, M. Garnier, R. Hoessel, D. Marko, J.A. Bibb, G.L. Snyder, P. Greengard,
J. Biernat, E.-M. Mandelkow, G. Eisenbrand, L. Meijer, Indirubins inhibit
8] C. Neagoie, E. Vedrenne, F. Buron, J.Y. M eꢀ rour, S. Rosca, S. Bourg, O. Lozach,
L. Meijer, B. Baldeyrou, A. Lansiaux, S. Routier, Synthesis of chromeno[3,4-b]
indoles as lamellarin D analogues: a novel DYRK1A inhibitor class, Eur. J. Med.
Chem. 49 (2012) 379e396;
Y. Hajbi, C. Neagoie, B. Biannic, A. Chilloux, E. Vedrenne, B. Baldeyrou, C. Bailly,
J.Y. M eꢀ rour, S. Rosca, S. Routier, A. Lansiaux, Synthesis and biological activities
of new furo[3,4-b]carbazoles: potential topoisomerase II inhibitors, Eur. J.
Med. Chem. 45 (2010) 5428e5437;
P. Kassis, J. Brzeszcz, V. B eꢀ n eꢀ teau, O. Lozach, L. Meijer, R. Le Gu eꢀ vel,
C. Guillouzo, K. Lewi nꢀ ski, S. Bourg, L. Colliandre, S. Routier, J.Y. M eꢀ rour, Syn-
thesis and biological evaluation of new 3-(6-hydroxyindol-2-yl)-5-(phenyl)
pyridine or pyrazine V-shaped molecules as kinase inhibitors and cytotoxic
agents, Eur. J. Med. Chem. 46 (2011) 5416e5434;
glycogen synthase kinase e 3
b and CDK5/p25, two kinases involved in
abnormal tau phosphorylation in Alzheimer's disease e a property common
to most CDK inhibitors? J. Biol. Chem. 276 (2001) 251e260.
[14] A. Primot, B. Baratte, M. Gompel, A. Borgne, S. Liabeuf, J.L. Romette,
F. Costantini, L. Meijer, Purification of GSK-3 by affinity chromatography on
immobilised axin, Protein Expr. Purif 20 (2000) 394e404.
[15] Schr o€ dinger, LLC, New York, NY, 2014.
[16] Molecular Operating Environment, Version 2013.08, Chemical Computing
Group Inc., Montreal, Quebec, Canada, 2013.
[17] M. Aoki, T. Yokota, I. Sugiura, C. Sasaki, T. Hasegawa, C. Okumura, K. Ishiguro,
T. Kohno, S. Sugio, T. Matsuzaki, Structural insight into nucleotide recognition
U. Jacquemard, N. Dias, A. Lansiaux, C. Bailly, C. Log eꢀ , J.M. Robert, O. Lozach,
L. Meijer, J.Y. M eꢀ rour, S. Routier, Synthesis of 3,5-bis(2-indolyl)pyridine and 3-
in tau-protein kinase I/glycogen synthase kinase 3b, Acta Crystallogr. (2004)
439e446.
[(2-indolyl)-5-phenyl]pyridine derivatives as CDK inhibitors and cytotoxic
[18] J. Malmstr o€ m, J. Viklund, C. Slivo, A. Costa, M. Maudet, C. Sandelin, G. Hiller, L.-
L. Olsson, A. Aagaard, S. Geschwindner, Y. Xue, M. Vas a€ nge, Synthesis and
structure-activity relationship of 4-(1,3-benzothiazol-2-yl)-thiophene-2-
sulfonamides as cyclin-dependent kinase 5 (cdk5)/p25 inhibitors, Bioorg.
Med. Chem. Lett. 22 (2012) 5919e5923.
agents, Bioorg. Med. Chem. 16 (2008) 4932e4953;
Synthesis and biological evaluation of novel oxophenylarcyriaflavins as po-
tential anticancer agents A. Bourderioux, V. B eꢀ n eꢀ teau, J.Y. M eꢀ rour,
B. Baldeyrou, C. Ballot, A. Lansiaux, C. Bailly, R. Le Gu eꢀ vel, C. Guillouzo,
S. Routier, Org. Biomol. Chem. 6 (2008) 2108e2117;
[19] K. Anderson, Y. Chen, Z. Chen, R. Dominique, K. Glenn, Y. He, C. Janson, K.-
C. Luk, C. Lukacs, A. Polonskaia, Q. Qiao, A. Railkar, P. Rossman, H. Sun,
Q. Xiang, M. Vilenchik, P. Wovkulich, X. Zhang, Pyrido[2,3-d]pyrimidines:
discovery and preliminary SAR of a novel series of DYRK1B and DYRK1A in-
hibitors, Bioorg. Med. Chem. Lett. 23 (2013) 6610e6615.
S. Routier, J.Y. M eꢀ rour, N. Dias, A. Lansiaux, C. Bailly, O. Lozach, L. Meijer,
Synthesis and biological evaluation of novel phenylcarbazoles as potential
anticancer agents, J. Med. Chem. 49 (2006) 789e799;
S. Routier, P. Peixoto, J.Y. M eꢀ rour, G. Coudert, N. Dias, C. Bailly, A. Pierr eꢀ ,
S. L eꢀ once, D.H. Caignard, Synthesis and biological evaluation of novel naph-
[20] http://www.chemaxon.com.
thocarbazoles as potential anticancer agents, J. Med. Chem. 48 (2005)
[21] J. Sadowski, J. Gasteiger, From atoms and bonds to three-dimensional atomic
coordinates: automatic model builders, Chem. Rev. 93 (1993) 2567e2581.
http://www.molecular-networks.com/products/corina.
1401e1413.
[
9] R. Boulahjar, A. Ouach, M. Chiurato, S. Bourg, M. Ravache, R. Le Gu eꢀ vel,