Synthesis and biological activity of N-aroyl-tetrahydro-γ-carbolines

Article abstract of DOI:10.1016/j.bmc.2010.04.034

Research on dual inhibitors of both 5-LOX and COXs gained interest due to the overexpressions of these enzymes during the malignant state of the evolution of prostate cancer. In order to take part in this research, new N-aroyl-tetrahydro-γ-carbolines issued from the modification of Indomethacin have been synthesised. As for the NSAIDs, the compounds have been tested for their activity against COX₁, COX₂ plus against 5-LOX and against the proliferation of malignant prostate cancer. Interesting cytotoxic activities and selectivities of some tetrahydro-γ-carboline derivatives have been obtained.

Full text of DOI:10.1016/j.bmc.2010.04.034

Bioorganic & Medicinal Chemistry 18 (2010) 3910–3924
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com/locate/bmc
Synthesis and biological activity of N-aroyl-tetrahydro-c-carbolines
*
Alexandre Bridoux , Régis Millet, Jean Pommery, Nicole Pommery, Jean-Pierre Henichart
Institut de Chimie Pharmaceutique Albert Lespagnol, EA 2692, Université Lille-Nord de France, 3, rue du Professeur Laguesse, B.P. 83, 59006 Lille, France
a r t i c l e i n f o
a b s t r a c t
Article history:
Research on dual inhibitors of both 5-LOX and COXs gained interest due to the overexpressions of these
enzymes during the malignant state of the evolution of prostate cancer. In order to take part in this
research, new N-aroyl-tetrahydro-c-carbolines issued from the modification of Indomethacin have been
synthesised. As for the NSAIDs, the compounds have been tested for their activity against COX1, COX2 plus
against 5-LOX and against the proliferation of malignant prostate cancer. Interesting cytotoxic activities
Received 31 December 2009
Revised 13 April 2010
Accepted 14 April 2010
Available online 18 April 2010
and selectivities of some tetrahydro-
c
-carboline derivatives have been obtained.
Ó 2010 Elsevier Ltd. All rights reserved.
Keywords:
5-LOX/COXs dual inhibitors
Cytotoxicity
Tetrahydro-
2D NMR
c-carbolines
1. Introduction
ative and an Endothelin A receptor antagonist (Fig. 1), during clin-
ical evaluations led to consider new therapeutic approaches of the
disease.2 As the incidences of the analogous overexpressions of 5-
lipoxygenase (5-LOX) and cyclooxygenases (COXs) enzymes were
recently associated to the development of the malignancy of pros-
tate cancer,3–8 anti-inflammatory dual 5-LOX/COXs inhibitors such
as the diaryl pyrazole derivatives, Tepoxaline (5-(4-chlorophenyl)-
Few chemotherapeutic agents have been tested to treat the hor-
mono-independent state of prostate cancer and the reference
treatment at this stage was changed in 2004 to the combination
of docetaxel and prednisone (Fig. 1).1 Moreover, the recent failures
of molecules like atrasentan, a pyrrolidine-3-carboxylic acid deriv-
HO
Me
O
Me
Me
O
HO
Me
Me
Me
O
O
Me
O
OH
Me
O
O
O
HO
Me
S
Me
H
OH
O
NH
O
O
O
O
O
Me
Me
O
H
H
N
F
N
N
O
Me
N
H
N
N
O
OH
OH
O
HO
O
H
H
Me
O
O
O
O
N
Me
O
O
Cl
Me
Me
Docetaxel
Prednisone
Atrasentan
Tepoxaline
ALIOX 18
COOH
Me
O
MeO
Me
F
O
S
OMe
O
Me
O
HO
N
NH2
O
S
N
N
O
CF3
O
O
Me
N
O
S
Me
O
N
Me
MeO
Cl
Cl
Indomethacin analogue
Selective COX2 inhibitor
Indomethacin
Non selective COXs inhibitor
Zileuton
Itazigrel
ZD2138
Figure 1. Selected anti-prostate cancer drugs and structures of dual 5-LOX/COXs inhibitors, 5-LOX inhibitors and of COX inhibitors.
* Corresponding author. Tel.: +33 (0) 320892121.
E-mail address: abridoux@wanadoo.fr (A. Bridoux).
0968-0896/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2010.04.034

A. Bridoux et al. / Bioorg. Med. Chem. 18 (2010) 3910–3924
3911
Table 1
with a 5-LOX inhibitor—the methoxytetrahydro-pyran (MTHP),
via a polymethylenic spacer (Fig. 2). In order to obtain a good fit
of the potential ligands, the length of the linker has needed to be
probed. Therefore, the docking of several compounds in compari-
son to ALIOX18 has been done in the COX2 active site (Fig. 3, as
an example). Using the docking method Gold, linkers bearing be-
tween one and three carbon atoms have been found suitable for
the hit development phase of the study. In regards to the substitu-
ents, those on the R1 position have been chosen to probe if their
stereoelectronic effects (electron donating effect: F, OMe; electron
withdrawing effect: SO2Me, SO2NH2) may have generated different
activity and selectivity towards COX2. R2 has been a suitable site to
attach the linker and the 5-LOX inhibitor—the MTHP. On the R3 po-
sition, substituents which were reported in the literature to opti-
mise the selectivity of Indomethacin or the activity of any COX2
inhibitors (C2Is) when beard on the lower ring have been se-
lected.17–20 The 2,4,6-trichlorobenzoyl showed to reverse the selec-
tivity of Indomethacin while halogen atoms and the sulfone
derivatives at the para position enhanced the activities of the
C2Is. Several synthesis strategies have then been applied to synthe-
sise these new compounds.
Relative potencies of selected molecules in ex vivo HWB assays on 5-LOX, COX1 and
COX2
Inhibitor
5-LOX IC50 COX1 IC50
M) M)
COX2 IC50
(lM)
COX2/COX1
(l
(l
ALIOX1836
0.2
0.02
0.7
—
>10
—
—
0.2
>10
9.7
—
—
0.5
4.3
ND
—
—
2.9
<0.05
ZD213826
Zileuton26
Indomethacin26
Indomethacin
analogue30
—
ND = not determinable.
N-hydroxy-(4-methoxyphenyl)-N-methyl-1H-pyrazole-3-propan-
amide)9 and ALIOX18 (3-(3-fluoro-5-(4-methoxytetrahydro-2H-
pyran-4-yl)phenoxymethyl)-1-[4-(methylsulfonyl)phenyl]-5-phe-
nyl-1H-pyrazole),10 have raised interest as one of these approaches
(Fig. 1, Table 1). These were synthesised because inhibiting only a
sole biosynthetic pathway has proven to switch the metabolism of
arachidonic acid (AA) to the other pathway, thus leading to the
overexpression of that one and to potential side effects.11 In the lit-
erature, numerous NSAIDs, the reference in the inhibition of COXs,
were also selected to be tested as anti-cancer drugs in clinical tests.
These had a potential to inhibit the development of malignant
cells.12 On the other hand, the anti-cancer action of the best inhib-
itors have not yet been associated in full with COXs’ enzymatic
activities.13 For instance, Indomethacin, a greater inhibitor of
COX1 than COX2, proved to block the stimulation of the growth
of very invasive and androgen-independent metastatic cells. The
application of prostaglandins on the same cells did not correct
the anti-cancer effect.12,14 Some NSAIDs have also shown to sup-
press a crosstalk discovered between COX2 and the sprouting of
2.1.
c-Carbolines as new dual inhibitors
c-Carbolines, or pyrido[4,3-b]indoles, were reported as planar
tricyclic azacarbazoles composed of a homocycle, a pyrrole and a
pyridine.21 The reduced forms—dihydro-, tetrahydro- and hexahy-
dro-c-carbolines were also of potent interest in the past; here,
about a better insertion in the COX active sites and due to some
flexibility found in the piperidine ring, only the tetrahydro and
hexahydro derivatives have been considered. Between the two
core structures, only the N-aroyl-tetrahydro-c-carboline model
has been chosen because both aromatic rings (indole and benzoyl)
formed a dihedral angle of 45° instead of 26° for the hexahydro
derivative in the lowest-energy conformations. That arrangement
paralleled the geometry of Indomethacin with a dihedral angle of
43° (calculated using the software Chem3DÒ Pro 5.0).
new vascular vessels mediated by the integrin avb3, a cell adhesion
molecule (CAM), in cancer diseases.15,16 In order to take share in
the research on androgen-independent prostate cancer, new N-ar-
oyl-tetrahydro-c-carbolines intended to inhibit 5-LOX and COXs
have been designed based on the template Indomethacin. They
have then been synthesised and biologically tested for their activ-
ities against each enzyme and against the proliferation of malig-
nant cells.
2.2. Leukotrienes biosynthesis inhibitors
5-LOX inhibitors were classified in three categories that dif-
fered in terms of enzyme selectivity and interaction with the iron
atom, for example, in regards of their mechanism of action.22
Tested redox inhibitors showed only weak selectivity for the en-
zyme, an activity which was rationalised by their ability to inter-
act with other redox biochemical systems. For instance, the
hydroxamic acid moiety found on several inhibitors was reported
as being also a chelator of the zinc ion in Matrix Metallo Protease
(MMP).23 To the contrary, Zileuton (N-(1-benzo[b]thien-2-yleth-
yl)-N-hydroxyurea, Abbott) displayed the highest binding affinity
and selectivity to chelate the iron ion of 5-LOX due to the N-
hydroxyurea function (Fig. 1, Table 1).24 The competitive non-re-
2. Rational design
At first, interesting structures have been selected from the liter-
ature and based on the structure–activity relationships (SARs) cri-
teria found, a new general dual inhibitor template has been
generated. In other words, ALIOX18 had previously revealed their
potential to inhibit both COX2 and 5-LOX at low concentrations
(Table 1). It has thus seemed interesting to develop and then to test
the unforeseen condensation of Indomethacin with a 5-LOX inhib-
itor. This new dual inhibitor template has been obtained from the
condensation of an N-aroyl-8-substituted-tetrahydro-c-carboline
R1 = H ; F ; OMe ; SO2Me ; SO2NH2
F
R2
F
Cl
X
R1
R2 = H ; (CH2)n
O
R1
NH
N
O
HO
MeO
Synthon C
O
N
MeO
n = 1 - 3
R2
N
X
H
Synthon B
Synthon A
R3
R3 = H ; p-Br ; p-Cl ; p-F ; 12, 14, 16 - Cl ;
p-SO2Me ; p-SO2NH2
X = CO; CH2
Figure 2. Novel dual 5-LOX/COXs inhibitors.

3912
A. Bridoux et al. / Bioorg. Med. Chem. 18 (2010) 3910–3924
Figure 3. 3D docking. (A) Compound 41 in the COX2 active site. (B) Superimposition of the compound 41 with ALIOX18.
dox class then arose from a research program which culminated
with lead compound ZD2138 (6-[3-fluoro-5-(4-methoxy-
TXA2.29 This trial unfortunately shaded the development of the
selective dual 5-LOX/COX2 inhibitors based on the structure of
the diaryl heterocycles. Meanwhile, a novel C2I evolved from Indo-
methacin (Fig. 1, Table 1) was reported.30 The selectivity for COX2
emerged because the substituent on the aromatic ring was bulky
enough to prevent the entry of the compound in the COX1 active
site. The relative safe profile of the drug thus allowed considering
with ease the modification of the N-benzyl or N-benzoyl-5-indole
framework of these compounds by ring closure into a semi-rigid
a
3,4,5,6-tetrahydro-4H-pyran-4-yl)phenoxy]methyl]-1-methylqui-
nol-2-one, Astra Zeneca) (Fig. 1, Table 1). This compound resulted
from an optimisation study on an enantioselective methoxyethyl-
thiazole hit compound.25 In the structure of ZD2138, the meth-
ylquinolonyl was only used as a more soluble alternative to a
naphthyl moiety and the SAR studies proved that only the achiral
MTHP part held the activity. Further optimisation of that lead
cleared up the fact that the oxygen on the saturated ring needed
to be separated from the fluorophenyl ring of at least two satu-
rated carbon atoms for a good activity and that the halogen on
the phenyl ring blocked a potential site of metabolism. Molecular
modelling studies also helped to visualise the active form of the
MTHP, for example, when the phenyl ring was in the equatorial
position.25 As it was used to obtain one of the best known dual
5-LOX/COX2 inhibitors,10 the MTHP has also been the preferred
5-LOX inhibitor in this study.
analogue—a N-aroyl-tetrahydro-c-carboline.
3. Results and discussion
A synthesis strategy of the potential dual inhibitors has been
developed starting from 4-substituted-phenylhydrazine hydro-
chlorides and 4-piperidine derivatives which were cyclised in tet-
rahydro-c
-carbolines by acid catalysis.31 Then a NMR study has
helped to check the stereochemistry and the conformation of the
synthesised compounds in organic solvents.
2.3. Prostaglandin biosynthesis inhibitors
3.1. Synthesis strategy
Non-selective COXs inhibitors (NSAIDs)—Aspirin (acetyl salicylic
acid, Bayer), Indomethacin, the ‘Profen’ family, Ketorolac (( )-5-
benzoyl-2,3-dihydro-1H-pyrrolizine-1-carboxylic acid, Roche) and
Diclofenac (2-[2-(2,6-dichlorophenyl)aminophenyl] ethanoic acid,
Novartis)26 were mainly approved for the relief of inflammation
and pain. To avoid gastric side effects, research led to the C2Is from
a lead optimisation study on the structure of the diaryl hetero-
cycle Itazigrel (4,5-bis(4-methoxyphenyl)-2-trifluoromethylthiaz-
ole, Pfizer) (Fig. 1).27 These new drugs were introduced on the mar-
ket to treat acute arthritis symptoms; some even entered some
clinical trials against cancer before cardiovascular side effects pre-
cluded them from any new trials.28 These baleful effects have then
been rationalised by the fact that C2Is, as they respect COX1, broke
the equilibrium between prostaglandin E2 (PGE2) and thromboxane
A2 (TXA2) in the benefit of the proaggregating and vasoconstrictor
The strategy has relied on the condensation of three synthons:
an 8-substituted-tetrahydro-c-carboline (synthon A); a para
substituted aroyl chloride (synthon B) and the MTHP framework
(synthon C) (Fig. 2). The MTHP has been synthesised by a reaction
sequence adapted from a published procedure.32 The synthesis of
8-substituted-tetrahydro-c-carbolines has called out an exother-
mic aza-Cope [3,3] sigmatropic reaction as an intermediate step
in the cyclisation process.31 The compounds that have been ob-
tained with the highest yield have then served as building blocks
in the first pursued strategy. In this linear strategy, the target com-
pounds have easily appeared accessible when looking at the con-
densation of a N-alkylated tetrahydro-c-carboline intermediate
by the spacer chain with the phenol (synthon C). Despite some
intermediate molecules have successfully resulted from the con-

A. Bridoux et al. / Bioorg. Med. Chem. 18 (2010) 3910–3924
3913
densation of the protected synthon A with the synthon B, this
strategy has revealed a weakness: an unforeseen debenzylation.
This self dissociation was reported on the structure of Indometha-
cin only in aqueous condition; here, an inorganic material has been
enough to remove the benzoyl group in harsh organic conditions.33
The consideration of a new approach has led to a convergent, more
efficient and economic strategy which has used the difference in
basicity of the indole amine (pKa = 21.0) and the piperidine amine
been understood as the result of the in situ reaction of the amino-
sulfone group on the benzoyl with a molecule of dimethylformam-
ide (DMF). Deprotection of the dimethylaminomethylene group has
been tried by refluxing the compound in an aqueous HCl (0.5 N)
solution in order to keep the unstable MeO (methoxy) moiety on
the MTHP but has not been successful.35
3.3. Structural characterisation
(pKa = 11.0) on the tetrahydro-c-carboline framework to selec-
tively alkylate the piperidine amine. This one has revealed to be
From the beginning, the carbonyl of the N-benzoyltetrahydro-c-
successful.
carboline structure has been hypothesised to lie between the two
protons of the b-carbon of the piperidine and the aromatic ring
to position itself perpendicularly to the indole ring. A fine 2D
NMR study combined to molecular modelling has helped to deter-
mine their geometry and their true orientation in deuterated sol-
vent conditions. On the obtained spectrum after the NMR
analysis, an Overhauser correlation peak has been assigned be-
tween the protons of the benzoyl (H8 + H11) and the homocycle
(H4) (Fig. 6). Furthermore, a clear shielding effect of the homocycle
protons has been assigned on the 1H NMR spectra of all compounds
after benzoylation. Together with the detected high field shift of
3.2. Synthesis
Fischer indole synthesis has been applied to prepare 8-substi-
tuted-tetrahydro-c-carbolines 1–5 by reacting equimolar quanti-
ties of substituted arylhydrazines with N-protected-4-piperid
inones or 4-piperidinone hydrochloride, as reported.31 Then, start-
ing from compounds 1 and 4, compounds 13 and 14 have been ob-
tained by the method listed in Figure 4. This method has allowed
synthesising N-benzoylated analogues (compounds 6–10) in yields
ranging in between 30% and 67% depending on the stereoelectronic
the protons on the
clusion has been made that the N-benzoyltetrahydro-
structure had a twisted structure with a benzoyl that drifted to
be perpendicular to the homocycle plane to optimise the –H con-
a- and b-carbons of the piperidine ring, the con-
c
-carboline
nature of the substituent on the tetrahydro-c-carboline; com-
pounds, obtained as oils, have been converted to the corresponding
hydrochlorides. The benzoylated compounds have then been re-
acted under catalytic hydrogenation conditions. Compounds 7, 8
and 10 have not reacted under such conditions whereas compounds
11 and 12 have been obtained quantitatively. Nevertheless,
compound 10 has alternatively been debenzylated following the
method using vinyl chloroformate (VOC-Cl); via a peculiar SN1 sub-
stitution of the benzyl group.34 Further decarbamoylation of the
vinylcarbamate intermediate, which existence has been monitored
by the full analysis of analytical samples, has occurred using HCl gas
in MeOH at reflux in 70% yield (Fig. 4). Key to the following conver-
gent strategy has been the optimisation of the phenol alkylation
step which has clearly justified 1-bromo-3-chloropropane as the
best alkylating agent for an efficient synthesis (Fig. 5). The selective
alkylation of the amine has resulted in intermediate molecules
(compounds 26–29). Those have been aroylated and alkylated to
get the desired compounds 30–41. Interestingly, alkylation of com-
pound 25 using an excess of compound 19 and base has resulted in
a surprising double alkylation. Compound 42 has thus been ob-
tained in addition to compound 29 and in the same yield (Fig. 5)
after purification by silica gel chromatography. Compound 38 has
p
tacts (Fig. 6). The compounds had thus the same conformation as
Indomethacin when tested in such conditions.
3.4. Biological evaluation
Ex vivo and in vitro cytotoxic potencies of the novel compounds
30–42 have been reported in Tables 2 and 3. These tests have been
done to evaluate the hybrid N-aroyl-tetrahydro-
cules as dual 5-LOX/COXs inhibitors and as cytotoxic compounds.
The tetrahydro- -carbolines 11, 12 and 16 have been assayed as
c-carboline mole-
c
negative indicators.
The screening of dual inhibitors was relatively easy in vitro by
using classical enzyme models and the purified or recombinant
proteins or using other techniques to quantify the resulting eicos-
anoid products. However, these methods did not reflect the situa-
tion in the whole organism where the COX/LOX systems mutually
interact and the end result as a balance between both metabolic
pathways. Thus a technique using a human whole blood assay
has been considered a more appropriate screening system.36
Cl
Bn
R1
R1
R1
R1
c
b
N
a
NH
Cl
N
N
+
O
N
H
N
N
N
Quantitative
30 - 67%
O
, HCl
O
O
, HCl
1-5
6-10
11, R1= OMe
12, R1= H
13, R1= OMe 62%
14, R1= H 17%
1, R1= OMe
2, R1= Br
3, R1= SMe
4, R1= H
6, R1= OMe
7, R1= Br
8, R1= SMe
9, R1= H
5, R1= SO2Me
10, R1= SO2Me
O
Me
O
O
Me
O
O
Me
O
O
Bn
O
S
S
S
e
NH
N
N
N
d
N
O
N
O
O
, HCl
10
15
16, 70%
Figure 4. Linear synthesis and debenzylation using the VOC method. Reagents and conditions: (a) (1) NaH 60% (1.0 equiv), DMF, 2 h, 0 °C, N2; (2) benzoyl chloride (1.0 equiv),
2 h, rt, 30–67%; (b) Pd/C 10%, H2, solvent, atm P., 48 h, rt, quantitative; (c) (1) DIEA (2.0 equiv), DCM, 30 min, rt; (2) 1-bromo-3-chloropropane (1.0 equiv), DCM, 24 h, rt; (d)
VOC-Cl (1.0 equiv), DCM, 1 h, reflux, N2; (e) (1) HCl, DCM, rt; (2) MeOH, 2 h, reflux, N2, 70%.

3914
A. Bridoux et al. / Bioorg. Med. Chem. 18 (2010) 3910–3924
F
f
O
Cl
O
Quantitative
MeO
18
O
F
F
F
OMe
OF
g
O
O
+
O
Br
O
HO
O
MeO
19, 53%
MeO
MeO
17
20, 9%
F
h
O
Cl
O
MeO
21
35%
NH
R1
N
H
F
F
22-25
O
O
22, R1= OMe
23, R1= F
24, R1= H
O
MeO
R1
O
R1
MeO
j
N
N
i
25, R1= SO2Me
N
Cl
N
X
Br
H
9-28%
O
or
, HCl
R3
R3
R3
26, R1= OMe
27, R1= F
28, R1= H
F
10-50%
O
30, R1= OMe, X= CO, R3= H
31, R1=H, X= CO, R3= H
32, R1= OMe, X= CO, R3= 2-F
33, R1= OMe, X= CO, R3= 3-F
34, R1= OMe, X= CO, R3= 4-F
Cl
O
29, R1= SO2Me
MeO
18
35, R1= OMe, X= CO, R3= 4-Cl
36, R1= OMe, X= CO, R3= 2,4,6-triCl
37, R1= OMe, X= CO, R3= 4-Br
38, R1= OMe, X= CO, R3=
4-SO2NCHN(Me)2
39, R1= OMe, X= CH2, R3= 4-SO2Me
40, R1= F, X= CH2, R3= 4-SO2Me
41, R1= SO2Me, X= CO, R3= H
F
O
OMe
O
F
O
O
S
NH
Me
Me
N
S
k
O
O
+
F
O
N
H
N
Cl
O
MeO
O
9%
O
25
18
MeO
42
Figure 5. Convergent synthesis and synthesis of compound 42. Reagents and conditions: (f) 1-bromo-3-chloropropane (1.0 equiv), Cs2CO3 (1.5 equiv), DMF, 2 h, rt, N2,
quantitative; (g) 1,3-dibromopropane (1.0 equiv), Cs2CO3 (3.0 equiv), DMF, 17 h, rt, N2; (h) 1-bromo-2-chloropropane (2.0 equiv), Cs2CO3 (2.0 equiv), acetone, 24 h, reflux, N2,
35%; (i) compound 18 (1.0 equiv), Cs2CO3 (2.0 equiv), acetone, 24 h, reflux, N2, 9–28%; (j) (1) NaH 60% (1.0 equiv), DMF, 2 h, 0 °C, N2; (2) benzoyl chloride or benzyl bromide
derivative (1.0 equiv), 2 h, rt, N2; (3) iPrOH–HCl (5–6 M) (1.0 equiv), 10–50%; (k) compound 18 (2.6 equiv), Cs2CO3 (2.6 equiv), acetone, 24 h, reflux, N2, 9%.
3.4.1. Dual inhibitor activity
mination of an apparent COX2/COX1 selectivity for the compounds
studied.
The dual inhibitory effects have been measured ex vivo on
5-LOX and COXs on heparinised human whole blood (HWB). Hep-
arin has been used to prevent coagulation. Also, a simplified
extraction procedure and a modified activation procedure have
been used in an attempt to differentiate between COX1 and COX2
activities. Then a simple HPLC method has been operated in order
to evaluate the selectivity of the synthesised compounds in a more
representative manner than the human whole cell assay (Table 2).
Leukotriene B4 (LTB4) and 5-hydroxyeicosatetraenoic acid (5-
HETE) have been used as indicators of 5-LOX activity. Similarly,
measuring the production of 12-hydroxyheptadecatrienoic acid
(12-HHTr) and of 12-HHTr* has provided information on the activ-
ities of COX1 and COX2, respectively. The longer incubation time
and additional stimulation by lipopolysaccharide (LPS) gave infor-
mation on the extent of induction of COX2 and permitted the deter-
The activities of Indomethacin (IC50(COX1) = 0.3
(COX2) = 0.5 M) and Zileuton (IC50(5-LOX) = 0.8 M) have ranged
in the same order as the ones described in the literature whereas
lM; IC50
l
l
Celecoxib (IC50(COX1) = 13.0 lM; IC50(COX2) = 0.8 lM) had a
weaker activity.24,26 At first glimpse, the first results justified the
importance of the MTHP for a balanced activity. The compound
34 (R1 = OMe, R2 = (CH2)3MTHP, X = CO, R3 = 4-F; IC50(5-LOX) =
60.0
l
M;
%
of inhibition of COX1 at 10
lM = 71.6%; IC50-
(COX2) = 54.0
l
M) has revealed the best balanced activity. On the
whole, these compounds had an activity with IC50 values a hundred
times higher than the ones of the reference compounds and were
only COX1 selective. The activities on 5-LOX were higher than
expected and varied greatly from one compound to another. The
compound 35 (R1 = OMe, R2 = (CH2)3MTHP, X = CO, R3 = 4-Cl;

A. Bridoux et al. / Bioorg. Med. Chem. 18 (2010) 3910–3924
3915
H4
F
19
22
21
O
18
O
23
24
OMe
25
17
7
15
6
20
MeO
1
N
16
2
5
N
4
3
8
9
O
O
, HCl
38
11
S
N
10
O
N
Me
12
14
H8 + H11
Me
13
O
O
OMe
MeO
Homocycle
Benzoyl
N
N
H
O
, HCl
O
S
π-H
interactions
N
O
Me
N
Benzoyl
Me
Figure 6. 2D NMR (ROESY) study of compound 38; 2D and space conformation (rear view) of compound 38.
IC50(5-LOX) = 119.0
l
M; IC50(COX1) = 7.0
l
M; IC50(COX2) = 198.0
R2 = (CH2)3MTHP, X = (CH2)3MTHP, no benzoyl); IC50 (L-1210)
= 3.0 M and IC50 (PC-3) = 6.0 M have shown better potencies in
comparison to Celecoxib (IC50 (L-1210) = 44.0 M; IC50 (MCF-
7) = 50.0 M and IC50 (PC-3) = 48.0 M) (Table 3). Among the most
active compounds, none of those have exhibited cytotoxicity toward
the hormono-dependent breast cancer (MCF-7) cell lines. Com-
pound 35 (R1 = OMe, R2 = (CH2)3MTHP, X = CO, R3 = 4-Cl; IC50 (L-
lM), closely related to Indomethacin, had the best activity against
l
l
COX1 of the series. Nevertheless, this activity remained 10 times
higher than the one of the reference compound. Overall, the selec-
tivity indexes (S) have shown the deterioration of the selectivity. On
the contrary of what has been stated in the literature, a bulky tri-
chlorobenzoyl, compound 36 (R1 = OMe, R2 = (CH2)3MTHP, X = CO,
l
l
l
R3 = 2,4,6-triCl; IC50(5-LOX) = 55.0
IC50(COX2) = 100.0 M; S = 2.7), has not reversed the selectivity be-
tween the COXs. The MeSO2 group either on the -carboline ring,
compound 41 (R1 = SO2Me, R2 = (CH2)3MTHP, X = CO, R3 = H; IC50
(COX1) = 24.0 M; % of inhibition of COX2 at 10 M = 8.4%), have
l
M; IC50(COX1) = 37.0
l
M;
1210) = 8.0 lM and IC50 (MCF-7) = 8.0 lM), the closest in structure
l
to Indomethacin, has proven to be active against L-1210 and MCF-
7 cells but not against hormono-independent cells. Nonetheless,
the MeSO2 has been identified as a privileged group on the R3 posi-
tion from the activities displayed in Table 3 against prostate cancer
cell lines. On the whole, the most noteworthy events were that the
most Indomethacin-like compound (compound 35) induced cyto-
toxicity on the androgen-dependent cell line and modulating its
structure with R3 = 4-SO2Me (compound 39) shifted the selectivity
toward the androgen-independent cell line.
c
-
l
l
not induced a large selectivity towards COX2.
3.4.2. Cytotoxic activity
In parallel, the inhibition of cellular proliferation has been evalu-
ated against prostate adenocarcinoma cell line (PC-3), an androgen-
independent human cell line which originated from a bone metasta-
sis and which was considered as very invasive. Other tests have been
performed against murine leukaemia cell line (L-1210) and against
human androgen-dependent breast carcinoma cell line (MCF-7)
for comparison purposes. The MTT assay has monitored the change
of MTT (3-(4,5-dimethyl-1,3-thiazolidin-2-yl)-2,5-diphenyl-2H-
tetrazol-3-ium bromide) to formazan (4,5-dimethyl-2-{(E)-[(Z)-
phenyl(phenylhydrazono)methyl]diazenyl}-1,3-thiazole) in viable
cells; thus, the less formazan measured by a spectrophotometer
the greatest the effectiveness of the compound in causing death.
Compared to Celecoxib (4-[5-(4-methylphenyl)-3-(trifluoro-
methyl)pyrazol-1-yl]benzenesulfonamide, Pfizer), the N-benzoyl-
4. Conclusion
New therapeutic goals were set towards the inhibition of the
proliferation of prostate cancer. To reach these goals, a new con-
cept has been applied in enzymatic and cancer cell assays. It con-
sisted in the modification of Indomethacin (a COX inhibitor and a
potential anti-cancer agent) in tetrahydro-c-carbolines and their
condensation with a known 5-LOX inhibitor. These novel com-
pounds have been synthesised by a simple four-step synthesis.
Unfortunately, maybe because of the size of the linker, the com-
pounds had a low dual 5-LOX/COX inhibitory profile in the HWB
assay. This has precluded most of them from carrying interesting
antiproliferative activities against androgen-independent prostate
adenocarcinoma, androgen-dependent cancer and leukaemia cell
lines. More, as what was observed for Indomethacin, some tetrahy-
tetrahydro-c-carbolines (compounds 11 and 16) have appeared to
be deprived of activity; nevertheless, some of these compounds
bearing the MTHP and substituted on the R1 and R3 positions have
shown interesting activities. Compound 35 (R1 = OMe, R2 =
dro-c-carbolines remained active against very invasive androgen-
(CH2)3MTHP, X = CO, R3 = 4-Cl; IC50 (L-1210) = 8.0
(MCF-7) = 8.0 M), compound 38 (R1 = OMe, R2 = (CH2)3MTHP,
X = CO, R3 = 4-SO2NCHN(Me)2; IC50 (L-1210) = 6.0 M), compound
39 (R1 = OMe, R2 = (CH2)3MTHP, X = CH2, R3 = 4-SO2Me; IC50 (L-
1210) = 5.0 M and IC50 (PC-3) = 8.0 M), compound 40 (R1 = F,
R2 = (CH2)3MTHP, X = CH2, R3 = 4-SO2Me; IC50 (L-1210) = 5.0
and IC50 (PC-3) = 8.0 M) and compound 42 (R1 = SO2Me,
lM and IC50
independent cell lines without any found relationship with the re-
sults on the HWB tests. The activity on cancer cell lines depends
upon multifactorial mechanisms and it is obvious that 5-LOX/
COX enzymes inhibition is only one (but important) effect. Never-
theless, it seems that the strong/weak activity on enzyme has been
correlated with the activity ratio on cancer cell lines. For those tet-
l
l
l
l
lM
l

3916
A. Bridoux et al. / Bioorg. Med. Chem. 18 (2010) 3910–3924
Table 2
Relative potencies of compounds 11, 16, 30–42 in the ex vivo HWB assay
R2
N
R1
N
X
, HCl
R3
Molecules
Structures
IC50 (
l
M) and (mean % of inhibition at 10.0
lM)
Selectivity
LTB4
5-HETE
12-HHTr
12-HHTr*
Zileuton
Indomethacin (NS)
Celecoxib (S)
—
—
—
0.7 4.5
ND
ND
0.8 11.2
ND
ND
ND
0.3 0.0
13.1 8.2
ND
0.5 0.0
0.8 2.7
ND
0.55
0.06
R2 = H
11
16
R
1 = OMe; X = CO;
R3 = H
1 = SO2Me; X = CO;
R3 = H
ND
ND
ND
ND
6.0 2.1
87.6 13.7
ND
>10
ND
R
24.4 17.9
R
2 = (CH2)3MTHP
30
31
32
33
34
35
36
37
38
39
40
41
42
R
1 = OMe; X = CO;
66.4 2.0
92.9 9.4
39.3 4.7
38.0 7.1
58.0 4.3
59.3 0.7
45.4 1.6
47.4 1.2
ND
107.5 20.7
205.9 155.7
>10
(84.3%)
18.2 5.6
(83.5%)
7.8 2.3
(71.6%)
7.4 8.0
36.7 2.2
16.5 6.1
ND
78.3 6.7
101.9 9.8
126.0 34.6
357.2 24.8
53.6 7.4
197.9 29.0
100.0 0.0
85.4 9.1
ND
>7.8
5.6
R3 = H
1 = H; X = CO;
R3 = H
1 = OMe; X = CO;
R3 = 2-F
1 = OMe; X = CO;
R3 = 3-F
R
R
>10.0
>10.0
>5.4
>10.0
2.7
R
40.5 15.3
59.9 1.3
118.6 23.1
55.0 0.0
62.0 2.9
(81.4%)
R
R
1 = OMe; X = CO;
3 = 4-F
R1 = OMe; X = CO;
R3 = 4-Cl
R
1 = OMe; X = CO;
R3 = 2,4,6-triCl
1 = OMe; X = CO;
R3 = 4-Br
R
5.2
R
R
R
1 = OMe; X = CO;
3 = 4-SO2NCHN(Me)2
1 = OMe; X = CH2;
ND
76.6 45.3
29.5 0.0
ND
109.7 82.5
24.6 0.2
ND
ND
109.2 0.0
ND
ND
R3 = 4-SO2Me
1 = F; X = CH2;
R3 = 4-SO2Me
1 = SO2Me; X = CO;
R3 = H
1 = SO2Me; no benzoyl;
X = (CH2)3MTHP
R
180.3 53.7
24.0 14.0
ND
ND
R
(8.4%)
ND
R
ND
ND
ND
ND
S = selective.
NS = non-selective.
ND = not determinable.
rahydro-
c
-carbolines which could have been linked to the NSAIDs’
(TLC) was performed on precoated Kieselgel 60F254 plates (Merck);
compounds were visualised by UV and/or with iodine or ninhydrin.
Flash chromatography (FC) and column chromatography were per-
formed with silica gel Kieselgel Si 60, 0.040–0.063 mm (230–400
mesh ASTM) (Merck) and Geduran Si 60, 0.063–0.200 mm (70–
230 mesh ASTM) (Merck). Melting points were determined on a
Büchi 535 capillary melting point apparatus and remain uncor-
rected. The structures of all compounds were supported by IR spec-
tra on Brucker Vector 22 instrument and 1H NMR at 300 MHz on a
Brucker AC300P spectrometer or a Brucker DPX 300 AVANCE spec-
trometer. Chemical shifts (d) were reported as d (ppm) relative to
trimethylsilane (TMS) as internal standard, J in hertz, and the split-
ting patterns were designated as follows: s, singlet; d, doublet; ds,
doublet of singlet; dd, doublet of doublet; t, triplet; q, quartet; m,
multiplet; br, broad. Atmospheric pressure chemical ionisation
(APCI) mass spectra were obtained on a liquid chromatography
coupled to mass spectrometry (LC–MS) system Thermo Electron
Surveyor MSQ. The purity of some compounds was characterised
anti-cancer activities: perhaps they expressed their activities be-
cause they were very close in structure to Indomethacin. These ac-
tive tetrahydro-
potent than the reference drug, have deserved to get improved.
The synthesis of the 8-methylsulfonyl tetrahydro- -carboline
bearing two MTHP groups (compound 42, IC50 (PC-3) = 6.0 M,
IC50 (L-1210) = 3.0 M) have unexpectedly led to the most promis-
ing cytotoxic tetrahydro- -carboline. Therefore, the MeSO2 group
c-carbolines, which have been 10 times more
c
l
l
c
has been selected as a privileged functional group to keep in the
hit-to-lead development phase of this research study.
5. Experimental
5.1. Chemistry
Unless otherwise stated, moisture-sensitive reactions were stir-
red under a dry nitrogen atmosphere. Thin-layer chromatography

A. Bridoux et al. / Bioorg. Med. Chem. 18 (2010) 3910–3924
3917
Table 3
Relative potencies of compounds 11, 16, 30–42 in the in vitro cytotoxic assay
R2
N
R1
N
X
,HCl
R3
Molecules
Celecoxib
Structures
IC50
(
l
M) and (mean % of inhibition at 10.0 lM)
L-1210
44.0
MCF-7
PC-3
48.5
Me
50.2
CF3
N
N
O
H2 N
S
O
R
2 = H
11
16
R1 = OMe; X = CO;
R3 = H
(32%)
(0%)
(0%)
(0%)
(0%)
(7%)
R
1 = SO2Me; X = CO;
R3 = H
2 = (CH2)3MTHP
R
30
31
32
33
34
35
36
37
38
39
40
41
42
R1 = OMe; X = CO;
R3 = H
(20%)
(24%)
(45%)
(40%)
(44%)
8.0
(18%)
(30%)
(21%)
(8%)
(20%)
(6%)
(15%)
(44%)
(0%)
(9%)
(0%)
(0%)
(42%)
8.0
R
1 = H; X = CO;
R3 = H
R
R
1 = OMe; X = CO;
3 = 2-F
R1 = OMe; X = CO;
R3 = 3-F
R
1 = OMe; X = CO;
R3 = 4-F
1 = OMe; X = CO;
R3 = 4-Cl
(37%)
8.0
R
R
R
1 = OMe; X = CO;
3 = 2,4,6-triCl
(11%)
(42%)
6.0
(36%)
(39%)
(21%)
(27%)
(34%)
(15%)
(36%)
R1 = OMe; X = CO;
R3 = 4-Br
R
1 = OMe; X = CO;
R3 = 4-SO2NCHN(Me)2
1 = OMe; X = CH2;
R3 = 4-SO2Me
1 = F; X = CH2;
R3 = 4-SO2Me
1 = SO2Me; X = CO;
R3 = H
1 = SO2Me; no benzoyl;
X = (CH2)3MTHP
R
5.0
R
(38%)
(38%)
3.0
8.0
R
(37%)
6.0
R
by their retention time (rt.) by high-performance liquid chroma-
tography (HPLC) on a Kontron 325 System apparatus equipped
with a UV detector DAD 440L, in isocratic mode. Elemental analy-
ses were determined by the Service Central d’Analyses (CNRS,
Vernaison, France) and all analyses were within 0.4% of theory.
5-HETE, LTB4, 12-HHTr, LPS B4 from Escherichia coli and calcium
ionophore (A23187) were purchased from Sigma. The tetrahydro-
furan (THF) was dried and distilled over Na and benzophenone.
EtOH and MeOH were dried over molecular sieves 3.0 Å. Acetone,
acetonitrile (MeCN), DCM and dioxane were previously dried over
potassium carbonate (K2CO3) then over calcium chloride (CaCl2).
All the organic solutions were dried over MgSO4.
5.2. Syntheses of compounds 17–21
5.2.1. 3-Fluoro-5-(4-methoxytetrahydro-4H-4-pyranyl)phenol
(17)
The title compound was prepared as described by Pommery
et al.27
5.2.2. 4-[3-(3-Chloropropyloxy)-5-fluorophenyl]-4-methoxy-
tetrahydro-4H-pyran (18)
A solution of 1-bromo-3-chloropropane (2.5 mL, 25.2 mmol,
1.0 equiv) diluted in DMF (5 mL) was added dropwise to a mixture
of 3-fluoro-5-(4-methoxytetrahydro-4H-4-pyranyl)phenol (17)

3918
A. Bridoux et al. / Bioorg. Med. Chem. 18 (2010) 3910–3924
(3.8 g, 16.8 mmol, 1.0 equiv) dissolved in DMF (30 mL) and Cs2CO3
(8.3 g, 25.2 mmol, 1.5 equiv) at rt. After stirring for 17 h, the reac-
tion was quenched by adding H2O (100 mL) and the aqueous solu-
tion was stirred during 1 h and then extracted with DCM
(3 ꢀ 100 mL). The organic layer was filtered and evaporated under
vacuum. Yield 92%; mp 73 °C (from Et2O); colourless crystals; TLC
Rf 0.68 (DCM/AcOEt, 90/10); IR cmꢁ1: 1139, 1105, 1073; 1H NMR
(CDCl3) d: 1.96 (m, 4H, 2CH2), 2.24 (m, 2H, CH2), 3.00 (s, 3H,
CH3), 3.78 (m, 6H, 3CH2), 4.11 (t, J = 6.0 Hz, 2H, CH2), 6.55 (dd,
J = 10.0 Hz, J = 2.0 Hz, 1H, ArH), 6.71 (m, 1H, ArH), 6.76 (m, 1H,
ArH); MS (+APCI) m/z 271 (5.0) [M+HꢁMeOH]+ (calcd for
C14H17ClFO2 271.7 [M+HꢁMeOH]+).
in mineral oil, 1.0 equiv) at 0 °C in DMF (10 mL) was added
slowly an anhydride solution of 2,3,4,5-tetrahydro-1H-pyr-
ido[4,3-b]indole derivative (1.0 equiv) dissolved in DMF (20 mL).
The medium was stirred for 2 h at 0 °C. Then benzoyl chloride
(1.0 equiv) was added dropwise at 0 °C. The reaction medium
was then stirred during 2 h at rt. After filtration, the filtrate
was evaporated.
General procedure for catalytic hydrogenation of 5-benzoyl-2-ben-
zyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indoles: A solution of 5-ben-
zoyl-2-benzyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole derivative
and Pd/C 10% in a mixture of solvents including an alcohol was stir-
red under atmospheric H2 pressure for 48 h at rt. The solution was
then filtered with Celite and the filtrate was concentrated in vacuo.
General procedure for alkylation of 5-benzoyl-2,3,4,5-tetrahydro-
1H-pyrido[4,3-b]indoles. Method A: A solution of 5-benzoyl-2,3,
4,5-tetrahydro-1H-pyrido[4,3-b]indole chloride derivative (1.0
equiv) dissolved in DCM (50 mL) and N,N-diisopropylethylamine
(DIEA) (2.0 equiv) was stirred at rt during 30 min. The solution
was then added to a stirred solution of 1-bromo-3-chloropropane
(1.0 equiv) in DCM (7 mL). The reaction medium was stirred at rt
for 24 h, concentrated under vacuo and the residual oil was
then diluted in AcOEt (100 mL). The organic solution was washed
with a 10% K2CO3 solution (3 ꢀ 100 mL), dried over MgSO4, fil-
tered and evaporated. The residual oil was then purified by FC
5.2.3. 4-[3-(3-Bromopropyloxy)-5-fluorophenyl]-4-methoxytet-
rahydro-4H-pyran (19) and 1,3-di-[3-fluoro-5-(4-methoxytet-
rahydro-4H-4-pyranyl)phenoxy]propane (20)
A
solution of 3-fluoro-5-(4-methoxytetrahydro-4H-4-pyra-
nyl)phenol (17) (3.3 g, 14.4 mmol, 1.0 equiv) dissolved in DMF
(25 mL) was added dropwise to a mixture of 1,3-dibromopropane
(1.6 mL, 14.4 mmol, 1.0 equiv) diluted in DMF (25 mL) and Cs2CO3
(14.1 g, 43.2 mmol, 3.0 equiv) at rt. After stirring for 24 h, the reac-
tion was quenched by adding H2O (100 mL), and extracted with
AcOEt (3 ꢀ 100 mL). The organic layer was dried over MgSO4, fil-
tered and evaporated under vacuum. The residue was purified by
FC over silica gel using chromatography solvent (cyclohexane/
AcOEt, 90/10) to give a solution which was filtered and concen-
trated in vacuo.
Compound 19. Yield 53%; colourless oil; TLC Rf 0.80 (DCM/AcOEt,
50/50); IR cmꢁ1: 1138, 1105, 1073; 1H NMR (CDCl3) d: 1.86 (m, 4H,
2CH2), 2.26 (m, 2H, CH2), 2.94 (s, 3H, CH3), 3.54 (t, J = 6.0 Hz, 2H,
CH2), 3.75 (m, 4H, 2CH2), 4.04 (t, J = 6.0 Hz, 1H, ArH), 6.50 (d,
J = 10.0 Hz, 1H, ArH), 6.68 (d, J = 10.0 Hz, 1H, ArH), 6.70 (br, 1H,
ArH); MS (+APCI) m/z 315 (5.0) [MꢁMeOH], 317 (5.0) [M+2MeOH]
(calcd for C14H16BrFO2 315.1 [MꢁMeOH]).
over silica gel to give
evaporated.
a solution which was filtered and
Method B: To
a mixture of 5-benzoyl-2-(3-chloropropyl)-
2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole derivative (1.0 equiv)
and Cs2CO3 (1.5 equiv) in acetone (30 mL) was added a solution
of 3-fluoro-5-(4-methoxytetrahydro-4H-4-pyranyl)phenol (17)
(1.0 equiv) dissolved in acetone (10 mL). The stirred medium was
refluxed during 24 h, filtered after cooling to rt and the filtrate
was evaporated under vacuum. The residual oil was then purified
by FC over silica gel to give a solution which was filtered and
evaporated.
Method C: To a mixture of 2,3,4,5-tetrahydro-1H-pyrido[4,3-
b]indole derivative (1.0 equiv) and Cs2CO3 (1.0–2.6 equiv) in ace-
tone (30 mL) was added a solution of 4-[3-(3-chloropropyloxy)-
5-fluorophenyl]-4-methoxytetrahydro-4H-pyran (18) (1.5–2.6
equiv) dissolved in acetone (10 mL). The stirred medium was re-
fluxed during 24 h, filtered after cooling to rt and the filtrate was
evaporated under vacuum. The residual oil was then purified by
FC over silica gel to give a solution which was filtered and
evaporated.
Compound 20. Yield 7%; yellow oil; TLC Rf 0.63 (DCM/AcOEt, 50/
50); IR cmꢁ1: 1138, 1104, 1073; 1H NMR (CDCl3) d: 1.93 (m, 8H,
4CH2), 2.27 (m, 2H, CH2), 2.98 (s, 6H, 2CH3), 3.79 (m, 8H, 4CH2),
4.14 (t, J = 6.0 Hz, 4H, 2CH2), 6.54 (dd, J = 10.0 Hz, J = 2.0 Hz, 2H,
ArH), 6.68 (dd, J = 10.0 Hz, J = 2.0 Hz, 2H, ArH), 6.74 (m, 2H, ArH);
MS (+APCI) m/z 429 (4.4) [M+Hꢁ2MeOH]+ (calcd for C25H27F2O4
429.4 [M+Hꢁ2MeOH]+).
5.2.4. 4-[3-(2-Chloroethyloxy)-5-fluorophenyl]-4-methoxyte-
trahydro-4H-pyran (21)
A
solution of 3-fluoro-5-(4-methoxytetrahydro-4H-4-pyra-
General procedure for benzoylation and benzylation of 2-{3-[3-flu-
oro-5-(4-methoxytetrahydro-4H-4-pyranyl)phenoxy]propyl}-2,3,4,5-
tetrahydro-1H-pyrido[4,3-b]indole: To a stirred suspension of NaH
(60% dispersion in mineral oil, 1.0 equiv) at 0 °C in DMF (10 mL)
was added slowly an anhydride solution of 2-{3-[3-fluoro-5-(4-
methoxytetrahydro-4H-4-pyranyl)phenoxy]propyl}-2,3,4,5-tetra-
hydro-1H-pyrido[4,3-b]indole derivative (1.0 equiv) dissolved in
DMF (20 mL). The medium was stirred for 2 h at 0 °C. Then a ben-
zoyl chloride derivative (1.0 equiv) or 4-methanesulfonylbenzyl
bromide (1.0 equiv) was added dropwise at 0 °C. The reaction med-
ium was stirred during 2 h at rt, filtrated and the filtrate was evap-
orated. The residual oil was then diluted in a minimum volume of
nyl)phenol (17) (1.0 g, 4.4 mmol, 1.0 equiv) dissolved in acetone
(10 mL) was added dropwise to a mixture of 1-bromo-2-chloroeth-
ane (736 lL, 8.8 mmol, 2.0 equiv) diluted in DMF (25 mL) and
Cs2CO3 (4.3 g, 13.2 mmol, 3.0 equiv) at rt. After stirring for 24 h,
the reaction medium was filtered and the filtrate was evaporated
under vacuum. The solid that formed was then dissolved in DCM
(10 mL). The organic layer was washed with aqueous KOH solution
(1 N), dried over MgSO4, and evaporated under vacuum. The resi-
due was purified by FC over silica gel using chromatography sol-
vent (heptane/AcOEt, 60/40) to give a solution which was filtered
and concentrated in vacuo. Yield 35%; colourless oil; TLC Rf 0.51
(DCM/AcOEt, 90/10); IR cmꢁ1: 1140, 1104, 1073; 1H NMR (CDCl3)
d: 1.95 (m, 4H, 2CH2), 3.00 (s, 3H, CH3), 3.83 (m, 6H, 3CH2), 4.23
(t, J = 5.0 Hz, 2H, CH2), 6.55 (dd, J = 10.0 Hz, J = 2.0 Hz, 1H, ArH),
6.72 (m, 1H, ArH), 6.76 (m, 1H, ArH); MS (+APCI) m/z 257 (5.0)
[M+HꢁMeOH]+ (calcd for C13H15ClFO2 257.7 [M+HꢁMeOH]+).
acetone, added dropwise to
a 10% K2CO3 aqueous solution
(150 mL) and was allowed to precipitate during the night. After fil-
tration, the crude product was purified by column chromatography
(230–400 mesh) over silica gel to give a solution which was filtered
and evaporated. The residue was then diluted in chloroform
(CH3Cl) (10 mL) and transformed to a hydrochloride using a solu-
tion of HCl in isopropanol (iPrOH) (5.0–6.0 M) (0.2–1.0 mmol).
The solution was evaporated and the residue was sonicated in
Et2O (20 mL) to give a solid which was filtrated and dried over
phosphorous pentoxide (P2O5).
5.3. General procedures for the synthesis of compounds 6–16
and compounds 26–42
General procedure for benzoylation of 2,3,4,5-tetrahydro-1H-pyr-
ido[4,3-b]indoles: To a stirred suspension of NaH (60% dispersion

A. Bridoux et al. / Bioorg. Med. Chem. 18 (2010) 3910–3924
3919
5.3.1. 5-Benzoyl-2-benzyl-8-methoxy-2,3,4,5-tetrahydro-1H-
pyrido[4,3-b]indole hydrochloride (6)
silica gel using the mixture of solvents for chromatography (DCM/
AcOEt, 90/10) to give a solution which was filtered and concen-
trated in vacuo. Yield 30%; mp 175 °C (from MeOH); white crystals;
TLC Rf 0.24 (heptane/EtOAc, 50/50); IR cmꢁ1: 1674, 1318, 1148; 1H
NMR (CDCl3) d: 2.75 (m, 2H, CH2), 2.79 (m, 2H, CH2), 3.07 (s, 3H,
CH3), 3.71 (s, 2H, CH2), 3.81 (s, 2H, CH2), 7.32–7.56 (m, 8H, ArH),
7.59 (m, 4H, ArH), 7.97 (d, J = 2.0 Hz, 1H, ArH); MS (+APCI) m/z
445 (3.0) [M+H]+ (calcd for C26H25N2O3S 445.5 [M+H]+).
Following general procedure for benzoylation, NaH (958 mg,
24.0 mmol, 1.0 equiv), 2-benzyl-8-methoxy-2,3,4,5-tetrahydro-
1H-pyrido[4,3-b]indole (1) (7.0 g, 24.0 mmol, 1.0 equiv) and ben-
zoyl chloride (2.8 mL, 24.0 mmol, 1.0 equiv) gave the product
which was filtered and washed with EtOH 95% (25 mL). Yield
48%; mp 118 °C (from EtOH 95%); white crystals; TLC Rf 0.51
(DCM/EtOAc, 80/20); IR cmꢁ1: 2923, 1672, 1466; 1H NMR (CDCl3)
d: 2.72 (m, 4H, 2CH2), 3.67 (m, 2H, CH2), 3.79 (m, 2H, CH2), 3.83
(s, 3H, CH3), 6.73 (dd, J = 9.0 Hz, J = 2.0 Hz, 1H, ArH), 6.78 (ds,
J = 2.0 Hz, 1H, ArH), 7.26–7.58 (m, 11H, ArH); MS (+APCI) m/z
397 (5.5) [M+H]+ (calcd for C26H25N2O2 397.4 [M+H]+).
5.3.6. 5-Benzoyl-8-methoxy-2,3,4,5-tetrahydro-1H-pyrido[4,3-
b]indole (11)
Following general procedure for catalytic hydrogenation, 5-ben-
zoyl-2-benzyl-8-methoxy-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]in-
dole hydrochloride (6) (5.0 g, 10.5 mmol, 1.0 equiv) in the mixture
of solvents (DCM/EtOH, 50/50) (200 mL) gave the product. Yield
98%; mp >230 °C (from EtOH); grey crystals; TLC Rf 0.54 (DCM/
MeOH, 80/20); IR cmꢁ1: 3245, 1683; 1H NMR (CDCl3) d: 1.26 (br,
2H, NH, NH+), 3.15 (m, 2H, CH2), 3.43 (m, 2H, CH2), 3.79 (s, 3H,
CH3), 4.41 (m, 2H, CH2), 6.67 (d, J = 9.0 Hz, 1H, ArH), 6.85 (m, 1H,
ArH), 6.88 (t, J = 9.0 Hz, 1H, ArH), 7.48 (d, J = 7.0 Hz, 1H, ArH),
7.51 (d, J = 7.0 Hz, 1H, ArH), 7.63 (t, J = 7.0 Hz, 3H, ArH); HPLC (Kro-
masil C18, H2O/MeOH/TFA (46:54:0.1), k = 220 nm) rt.: 5.1 min
(100%); Anal. Calcd for C19H18N2O2ꢂHClꢂ1/2H2O (351.8): C, 64.96;
H, 5.70; N, 7.98. Found: C, 65.06; H, 5.79; N, 8.18; MS (+APCI) m/
z 307 (2.7) [M+H]+ (calcd for C19H19N2O2 307.3 [M+H]+).
5.3.2. 5-Benzoyl-2-benzyl-8-bromo-2,3,4,5-tetrahydro-1H-
pyrido[4,3-b]indole hydrochloride (7)
Following general procedure for benzoylation, NaH (293 mg,
7.3 mmol, 1.0 equiv), 2-benzyl-8-bromo-2,3,4,5-tetrahydro-1H-
pyrido[4,3-b]indole (2) (2.5 g, 7.3 mmol, 1.0 equiv) and benzoyl
chloride (850 lL, 7.3 mmol, 1.0 equiv) gave the product as an or-
ange oil which crystallised in MeCN (60 mL). Yield 55%; mp
>230 °C (from EtOH); white crystals; TLC Rf 0.94 (DCM/MeOH,
90/10); IR cmꢁ1: 2920, 1686; 1H NMR (CDCl3) d: 2.77 (m, 1H, CHH0),
3.00 (m, 1H, CHH0), 3.19 (m, 1H, CHH0), 3.52 (m, 1H, CHH0), 4.27 (s,
2H, CH2), 4.40 (s, 2H, CH2), 7.04–7.77 (m, 13H, ArH), 11.59 (br, 1H,
NH+); MS (+APCI) m/z 445 (3.5) [M], 447 (3.5) [M+2] (calcd for
C25H21BrN2O 445.3 [M]).
5.3.7. 5-Benzoyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole
hydrochloride (12)
5.3.3. 5-Benzoyl-2-benzyl-8-methylthio-2,3,4,5-tetrahydro-1H-
pyrido[4,3-b]indole hydrochloride (8)
Following general procedure for benzoylation, NaH (221 mg,
5.5 mmol, 1.0 equiv), 2-benzyl-8-methylthio-2,3,4,5-tetrahydro-
1H-pyrido[4,3-b]indole (3) (1.7 g, 5.5 mmol, 1.0 equiv) and benzoyl
Following general procedure for catalytic hydrogenation, 5-ben-
zoyl-2-benzyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole hydro-
chloride (7.1 g, 17.6 mmol, 1.0 equiv) in the mixture of solvents
(DCM/MeOH, 25/75) (400 mL) gave the product. Yield 90%; mp
>230 °C (from EtOH 95%); orange crystals; TLC Rf 0.12 (DCM/
MeOH, 90/10); IR cmꢁ1: 3395, 1632; 1H NMR (DMSO-d6) d: 2.90
(m, 2H, CH2), 3.36 (m, 2H, CH2), 4.35 (m, 2H, CH2), 7.18 (m, 3H,
ArH), 7.57–7.76 (m, 6H, ArH), 9.78 (br, 2H, NH, NH+); HPLC (Kroma-
sil C18, H2O/MeOH/TFA (50:50:0.1), k = 220 nm) rt.: 9.7 min
(99.6%); MS (+APCI) m/z 277 (2.6) [M+H]+ (calcd for C18H17N2O
277.3 [M+H]+).
chloride (641 lL, 5.5 mmol, 1.0 equiv) gave the product which was
filtered and washed with EtOH 95% (25 mL). Yield 48%; mp >230 °C
(from EtOH); white crystals; TLC Rf 0.69 (heptane/EtOAc, 60/40); IR
cmꢁ1: 2929, 1674, 1325; 1H NMR (CDCl3) d: 2.50 (s, 3H, CH3), 2.76
(m, 2H, CH2), 2.88 (m, 2H, CH2), 3.79 (s, 2H, CH2), 3.91 (m, 2H, CH2),
7.07 (d, J = 8.5 Hz, J = 2.0 Hz, 1H, ArH), 7.23 (d, J = 8.5 Hz, 1H, ArH),
7.32 (m, 6H, ArH), 7.60 (t, J = 7.0 Hz, 3H, ArH), 7.67 (d, J = 7.0 Hz,
2H, ArH); MS (+APCI) m/z 413 (3.5) [M+H]+ (calcd for C26H25N2OS
413.5 [M+H]+).
5.3.8. 5-Benzoyl-8-methanesulfonyl-2,3,4,5-tetrahydro-1H-
pyrido[4,3-b]indole (16)
Vinyl chloroformate (150 lL, 1.75 mmol, 1.0 equiv) was added
5.3.4. 5-Benzoyl-2-benzyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]
indole hydrochloride (9)
dropwise to a solution of 5-benzoyl-2-benzyl-8-methanesulfonyl-
2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole (780 mg, 1.75 mmol,
1.0 equiv) dissolved in DCM (25 mL). The reaction medium was re-
fluxed during 1 h then allowed to cool to rt and concentrated in va-
cuo. The residue was triturated in a mixture of solvents (heptane/
AcOEt, 70/30) to give the intermediate (compound 15) as a solid
which was sonicated, filtered and gave an analytical sample after
recrystallisation. The reaction intermediate was dissolved in DCM
(10 mL) and the solution was saturated with HCl and then evapo-
rated in vacuum. The red oily residue was refluxed in MeOH
(25 mL) during 2 h then allowed to cool to rt and concentrated in
vacuo. The product was precipitated in MeOH (10 mL) and filtered.
Compound 15. Yield 76%; mp 180 °C (from EtOH); yellow crys-
tals; TLC Rf 0.43 (heptane/AcOEt, 50/50); IR cmꢁ1: 1709, 1681,
1326, 1146; 1H NMR (DMSO-d6) d: 2.59 (m, 2H, CH2), 3.23 (s, 3H,
CH3), 3.68 (m, 2H, CH2), 4.57 (m, 1H, CHH0), 4.74 (m, 1H, CHH0),
4.88 (m, 2H, CH2 vinyl), 7.18 (dd, J = 6.0 Hz, J = 6.0 Hz, CH vinyl),
7.59 (m, 3H, ArH), 7.73 (m, 4H, ArH), 8.24 (s, 1H, ArH); MS (+APCI)
m/z 355 (3.0) [M+H]+ (calcd for C19H19N2O3 355.4 [M+H]+).
Following general procedure for benzoylation, NaH (1.2 g,
28.9 mmol, 1.1 equiv), 2-benzyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-
b]indole (4) (6.9 g, 26.3 mmol, 1.0 equiv) and benzoyl chloride
(3.0 mL, 26.3 mmol, 1.0 equiv) gave the product which was filtered
and washed with EtOH 95% (25 mL). Yield 67%; mp 143 °C (from
EtOH 95%); white crystals; TLC Rf 0.92 (DCM/MeOH, 90/10); IR
cmꢁ1: 2922, 1676; 1H NMR (CDCl3) d: 2.73 (m, 4H, 2CH2), 3.71 (s,
2H, 2CH2), 3.79 (s, 2H, 2CH2), 7.15 (m, 2H, CH2), 7.30–7.80 (m,
12H, ArH); MS (+APCI) m/z 367 (4.4) [M+H]+ (calcd for
C25H23N2O 367.4 [M+H]+).
5.3.5. 5-Benzoyl-2-benzyl-8-methanesulfonyl-2,3,4,5-tetra-
hydro-1H-pyrido[4,3-b]indole (10)
Following general procedure for benzoylation, NaH (350 mg,
10.4 mmol, 1.0 equiv), 2-benzyl-8-methanesulfonyl-2,3,4,5-tetra-
hydro-1H-pyrido[4,3-b]indole (5) (5.0 g, 10.4 mmol, 1.0 equiv)
and benzoyl chloride (1.2 mL, 10.4 mmol, 1.0 equiv) gave an oil
which was diluted in AcOEt (50 mL), washed with a 10% K2CO3
aqueous solution. The aqueous layer was extracted with Et2O
(3 ꢀ 150 mL). The combined organic layer was dried over MgSO4
and evaporated under vacuum. The residue was purified by FC over
Compound 16. Yield 70%; mp >230 °C (from MeOH); yellow
crystals; TLC Rf 0.63 (DCM/MeOH, 90/10 + NH4OH); IR cmꢁ1
:
1697, 1298, 1143; 1H NMR (CDCl3) d: 2.90 (m, 2H, CH2), 3.34 (s,
3H, CH3), 3.39 (m, 2H, CH2), 4.46 (s, 2H, CH2), 7.39 (d, J = 9.0 Hz,

3920
A. Bridoux et al. / Bioorg. Med. Chem. 18 (2010) 3910–3924
1H, ArH), 7.62 (m, 2H, ArH), 7.70–8.32 (m, 4H, ArH), 8.27 (s, 1H,
ArH), 9.55 (br, 2H, NH, NH+); Anal. Calcd for C19H18N2O2ꢂHClꢂ3/
4H2O (403.5): C, 56.50; H, 5.08; N, 6.94. Found: C, 56.63; H, 4.95;
N, 6.99; MS (+APCI) m/z 355 (2.7) [M+H]+, 396 (2.7) [M+H+MeCN]+
(calcd for C19H19N2O3S 355.4 [M+H]+).
J = 9.0 Hz, J = 2.0 Hz, 1H, ArH), 7.04 (dd, J = 10.0 Hz, J = 2.0 Hz, 1H,
ArH), 7.15 (dd, J = 8.0 Hz, J = 2.0 Hz, 1H, ArH), 8.15 (br, 1H, NH);
MS (+APCI) m/z 457 (3.2) [M+H]+ (calcd for C26H31F2N2O3 457.5
[M+H]+).
5.3.13. 2-{3-[3-Fluoro-5-(4-methoxytetrahydro-4H-4-pyranyl)
phenoxy]propyl}-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole (28)
Following general method C for alkylation, 2,3,4,5-tetrahydro-
1H-pyrido[4,3-b]indole (24) (1.2 g, 6.6 mmol, 1.0 equiv), Cs2CO3
(3.3 g, 9.9 mmol, 1.5 equiv) and 4-[3-(3-chloropropyloxy)-5-fluo-
rophenyl]-4-methoxytetrahydro-4H-pyran (18) (2.0 g, 6.6 mmol,
1.0 equiv) gave the product. Column eluent (AcOEt/EtOH, 90/10).
5.3.9. 5-Benzoyl-2-(3-chloropropyl)-8-methoxy-2,3,4,5-tetra-
hydro-1H-pyrido[4,3-b]indole (13)
Following general method A for alkylation, 5-benzoyl-8-meth-
oxy-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole hydrochloride (11)
(3.5 g, 10.3 mmol, 1.0 equiv), DIEA (4.3 mL, 20.7 mmol, 2.0 equiv)
and 1-bromo-3-chloropropane (1.1 mL, 11.4 mmol, 1.0 equiv) gave
the product. Column eluent (DCM/AcOEt, 80/20). Yield 62%; white
oil; TLC Rf 0.48 (DCM/AcOEt, 50/50); IR cmꢁ1: 1720, 1452; 1H NMR
(CDCl3) d: 2.13 (m, 2H, CH2), 2.75 (m, 6H, 3CH2), 3.68 (t, J = 8.0 Hz,
2H, CH2), 3.70 (s, 2H, CH2), 3.85 (s, 3H, CH3), 6.73 (dd, J = 9.0 Hz,
J = 2.0 Hz, 1H, ArH), 6.81 (d, J = 2.5 Hz, 1H, ArH), 7.27 (m, 1H,
ArH), 7.47–7.61 (m, 5H, ArH); MS (+APCI) m/z 383 (5.0) [M+H]+
(calcd for C22H24ClN2O2 383.8 [M+H]+).
Yield 28%; white oil; TLC Rf 0.20 (DCM/MeOH, 90/10); IR cmꢁ1
:
3300, 1460, 1455, 1072; 1H NMR (DMSO-d6) d: 1.87 (m, 4H,
2CH2), 2.31 (m, 2H, 2CH2), 2.89 (s, 3H, CH3), 3.36 (m, 2H, 2CH2),
3.65 (m, 8H, 4CH2), 3.74 (m, 1H, CHH0), 3.79 (s, 3H, CH3), 3.88
(m, 1H, CHH0), 4.14 (m, 2H, CH2), 6.78 (m, 3H, ArH), 6.92 (dd,
J = 9.0 Hz, J = 2.0 Hz, 1H, ArH), 7.54 (d, J = 9.0 Hz, 1H, ArH), 7.61
(d, J = 2.0 Hz, 1H, ArH), 10.05 (br, 1H, NH); MS (+APCI) m/z 439
(4.4) [M+H]+ (calcd for C26H32FN2O3 439.5 [M+H]+).
5.3.10. 5-Benzoyl-2-(3-chloropropyl)-2,3,4,5-tetrahydro-1H-
pyrido[4,3-b]indole (14)
5.3.14. 2-{3-[3-Fluoro-5-(4-methoxytetrahydro-4H-4-pyranyl)
phenoxy]propyl}-8-methanesulfonyl-2,3,4,5-tetrahydro-1H-
pyrido[4,3-b]indole (29) and 2,5-di{3-[3-fluoro-5-(4-methoxy-
tetrahydro-4H-4-pyranyl)phenoxy]propyl}-8-methanesulfonyl-
2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole (42)
Following general method C for alkylation, 8-methanesulfonyl-
2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole (25) (2.4 g, 9.6 mmol,
1.0 equiv), Cs2CO3 (8.3 g, 25.4 mmol, 2.6 equiv) and 4-[3-(3-chloro-
propyloxy)-5-fluorophenyl]-4-methoxytetrahydro-4H-pyran (18)
(7.7 g, 25.4 mmol, 2.6 equiv) gave the two products. Column eluent
(AcOEt/EtOH, 80/20).
Following general method A for alkylation, 5-benzoyl-2,3,4,5-
tetrahydro-1H-pyrido[4,3-b]indole hydrochloride (12) (4.9 g,
15.6 mmol, 1.0 equiv), DIEA (2.7 mL, 31.2 mmol, 2.0 equiv) and 1-
bromo-3-chloropropane (1.5 mL, 15.6 mmol, 1.0 equiv) gave the
product. Column eluent (DCM/AcOEt, 90/10). Yield 17%; white
oil; TLC Rf 0.54 (DCM/AcOEt, 90/10); IR cmꢁ1: 1680; 1H NMR
(CDCl3) d: 2.08 (m, 2H, CH2), 2.75 (m, 6H, 3CH2), 3.69 (t,
J = 7.0 Hz, 2H, CH2), 3.71 (s, 2H, CH2), 7.10–7.85 (m, 9H, ArH); MS
(+APCI) m/z 353 (5.5) [M+H]+ (calcd for C21H22ClN2O 353.8
[M+H]+).
Compound 29. Yield 9%; mp 223 °C (from EtOH); yellow crys-
tals; TLC Rf 0.39 (DCM/MeOH, 90/10); IR cmꢁ1: 3333, 1460, 1300,
1140, 1073; 1H NMR (CDCl3) d: 1.94 (m, 4H, 2CH2), 2.14 (m, 2H,
2CH2), 2.86 (t, J = 7.0 Hz, 2H, CH2), 2.96 (m, 4H, 2CH2), 3.01 (s,
3H, CH3), 3.09 (s, 3H, CH3), 3.78 (s, 2H, CH2), 3.84 (m, 4H, 2CH2),
4.11 (t, J = 7.0 Hz, 2H, CH2), 6.57 (ddd, J = 10.0 Hz, J = 2.0 Hz,
J = 2.0 Hz, 1H, ArH), 6.71 (ddd, J = 10.0 Hz, J = 2.0 Hz, J = 2.0 Hz,
1H, ArH), 6.76 (dd, J = 2.0 Hz, J = 2.0 Hz, 1H, ArH), 7.43 (dd,
J = 8.5 Hz, J = 1.0 Hz, 1H, ArH), 7.68 (dd, J = 8.5 Hz, J = 2.0 Hz, 1H,
ArH), 8.07 (d, J = 2.0 Hz, 1H, ArH), 8.29 (br, 1H, NH); MS (+APCI)
m/z 517 (3.1) [M+H]+, 485 (3.1) [M+HꢁMeOH]+ (calcd for
C27H34FN2O5S 517.6 [M+H]+).
Compound 42. Yield 10%; mp 223 °C (from EtOH); yellow crys-
tals; TLC Rf 0.52 (DCM/MeOH, 80/20); IR cmꢁ1: 3333, 1460, 1300,
1136, 1071; 1H NMR (CDCl3) d: 1.94 (m, 8H, 4CH2), 2.12 (m, 2H,
CH2), 2.25 (m, 2H, CH2), 2.83 (t, J = 7.3 Hz, 2H, CH2), 2.91 (m, 4H,
2CH2), 3.00 (s, 3H, CH3), 3.01 (s, 3H, CH3), 3.07 (s, 3H, CH3), 3.77
(s, 2H, CH2), 3.86 (m, 10H, 5CH2), 3.88 (t, J = 6.0 Hz, 2H, CH2),
4.08 (t, J = 6.0 Hz, 2H, CH2), 4.34 (t, J = 6.0 Hz, 2H, CH2), 6.57 (ddd,
J = 10.5 Hz, J = 2.0 Hz, J = 2.0 Hz, 1H, CH2), 6.72 (m, 4H, ArH), 7.40
(d, J = 9.0 Hz, 1H, ArH), 7.68 (dd, J = 9.0 Hz, J = 2.0 Hz, 1H, ArH),
8.07 (d, J = 2.0 Hz, 1H, ArH), 8.29 (s, 1H, ArH); Anal. Calcd for
C42H52F2N2O8Sꢂ1/2H2O (790.9): C, 63.71; H, 6.57; N, 3.54. Found:
C, 63.86; H, 6.69; N, 3.74; MS (+APCI) m/z 783 (3.6) [M+H]+, 751
(3.6) [M+HꢁMeOH]+, 719 (3.6) [M+Hꢁ2MeOH]+ (calcd for
C41H49F2N2O7S 751.8 [M+HꢁMeOH]+).
5.3.11. 2-{3-[3-Fluoro-5-(4-methoxytetrahydro-4H-4-pyranyl)
phenoxy]propyl}-8-methoxy-2,3,4,5-tetrahydro-1H-pyrido[4,3-
b]indole (26)
Following general method C for alkylation, 8-methoxy-2,3,
4,5-tetrahydro-1H-pyrido[4,3-b]indole (22) (3.0 g, 14.8 mmol,
1.0 equiv), Cs2CO3 (9.7 g, 29.7 mmol, 2.0 equiv) and 4-[3-(3-chloro-
propyloxy)-5-fluorophenyl]-4-methoxytetrahydro-4H-pyran (18)
(4.5 g, 14.8 mmol, 1.0 equiv) gave the product. Column eluent
(DCM/MeOH, 90/10). Yield 22%; white oil; TLC Rf 0.50 (DCM/MeOH,
90/10); IR cmꢁ1: 3270, 1460, 1455, 1076; 1H NMR (DMSO-d6) d:
1.87 (m, 4H, 2CH2), 2.31 (m, 2H, 2CH2), 2.89 (s, 3H, CH3), 3.36
(m, 2H, 2CH2), 3.65 (m, 8H, 4CH2), 3.74 (m, 1H, CHH0), 3.79 (s,
3H, CH3), 3.88 (m, 1H, CHH0), 4.14 (m, 2H, CH2), 6.78 (m, 3H,
ArH), 6.92 (dd, J = 9.0 Hz, J = 2.0 Hz, 1H, ArH), 7.54 (d, J = 9.0 Hz,
1H, ArH), 7.61 (d, J = 2.0 Hz, 1H, ArH), 10.05 (br, 1H, NH); MS
(+APCI) m/z 469 (3.3) [M+H]+ (calcd for C27H34FN2O4 469.5
[M+H]+).
5.3.12. 2-{3-[3-Fluoro-5-(4-methoxytetrahydro-4H-4-pyranyl)
phenoxy]propyl}-8-fluoro-2,3,4,5-tetrahydro-1H-pyrido[4,3-
b]indole (27)
Following general method C for alkylation, 8-fluoro-2,3,4,5-tet-
rahydro-1H-pyrido[4,3-b]indole (23) (2.8 g, 14.8 mmol, 1.0 equiv),
Cs2CO3 (6.5 g, 20.0 mmol, 2.0 equiv) and 4-[3-(3-chloropropyl-
oxy)-5-fluorophenyl]-4-methoxytetrahydro-4H-pyran (18) (4.5 g,
14.8 mmol, 1.0 equiv) gave the product. Column eluent (AcOEt/
EtOH, 90/10). Yield 13%; brown oil; TLC Rf 0.40 (AcOEt/EtOH, 90/
5.3.15. 5-Benzoyl-2-{3-[3-fluoro-5-(4-methoxytetrahydro-4H-4-
pyranyl)phenoxy]propyl}-8-methoxy-2,3,4,5-tetrahydro-1H-
pyrido[4,3-b]indole hydrochloride (30)
Following general procedure for benzoylation and benzylation,
NaH (23 mg, 0.6 mmol, 1.0 equiv), 2-{3-[3-fluoro-5-(4-methoxytet-
rahydro-4H-4-pyranyl)phenoxy]propyl}-8-methoxy-2,3,4,5-tetra-
hydro-1H-pyrido[4,3-b]indole (26) (270 mg, 0.6 mmol, 1.0 equiv),
1
10); IR cmꢁ1: 3303, 1079; H NMR (CDCl3) d: 1.89 (m, 1H, CHH0),
1.94 (m, 4H, 2CH2), 2.07 (m, 1H, CHH0), 2.15 (m, 2H, CH2), 2.85
(m, 2H, CH2), 2.91 (m, 2H, CH2), 3.00 (s, 3H, CH3), 3.72 (m, 2H,
CH2), 3.83 (m, 4H, 2CH2), 4.08 (m, 2H, CH2), 6.56 (ddd,
J = 10.0 Hz, J = 2.0 Hz, J = 2.0 Hz, 1H, ArH), 6.70 (dd, J = 10.0 Hz,
J = 2.0 Hz, 1H, ArH), 6.74 (m, 1H, ArH), 6.84 (ddd, J = 10.0 Hz,

A. Bridoux et al. / Bioorg. Med. Chem. 18 (2010) 3910–3924
3921
benzoyl chloride (67
l
L, 0.6 mmol, 1.0 equiv) and HCl–iPrOH (50
l
L,
1.0 equiv), 3-fluorobenzoyl chloride (416.5
equiv) and HCl–iPrOH (48
eluent (DCM/EtOAc, 60/40). Yield 10%; mp 213 °C (from iPrOH);
light brown crystals; TLC Rf 0.62 (EtOAc/EtOH, 90/10); IR cmꢁ1
l
L, 3.4 mmol, 2.0
0.3 mmol, 1.0 equiv) gave the product. Column eluent (DCM/EtOAc,
90/10). Yield 57%; mp 183 °C (from iPrOH); light brown crystals; TLC
Rf 0.78 (DCM/MeOH, 90/10); IR cmꢁ1: 2956, 1678, 1464; 1H NMR
(CDCl3) d: 1.92 (m, 4H, 2CH2), 2.62 (m, 2H, CH2), 2.99 (s, 3H, CH3),
3.00 (m, 1H, CHH0), 3.25 (m, 3H, CHH0, CH2), 3.47 (m, 4H, 2CH2),
3.70 (m, 1H, CHH0), 3.84 (s, 3H, CH3), 3.90 (m, 1H, CHH0), 4.14 (m,
2H, CH2), 4.15 (m, 1H, CHH0), 4.85 (m, 1H, CHH0), 6.53 (m, 1H, ArH),
6.74 (m, 4H, ArH), 6.91 (d, J = 9.0 Hz, 1H, ArH), 7.56 (t, J = 8.0 Hz,
1H, ArH), 7.63–7.73 (m, 4H, ArH), 13.40 (br, 1H, NH+); Anal. Calcd
for C34H37FN2O5ꢂHClꢂH2O (627.1): C, 65.12; H, 6.43; N, 4.47. Found:
C, 64.99; H, 6.21; N, 4.45; MS (+APCI) m/z 573 (3.6) [M+H]+ (calcd
for C34H38FN2O5 573.6 [M+H]+).
lL, 0.2 mmol) gave the product. Column
:
2954, 1687; 1H NMR (DMSO-d6) d: 1.87 (m, 4H, 2CH2), 2.34 (m,
2H, CH2), 2.85 (m, 1H, CHH0), 2.90 (s, 3H, CH3), 3.08 (m, 1H, CHH0),
3.36 (m, 2H, CH2), 3.67 (m, 1H, CHH0), 3.68 (m, 4H, 2CH2), 3.79 (s,
3H, CH3), 3.87 (m, 1H, CHH0), 4.15 (m, 2H, CH2), 4.33 (m, 1H, CHH0),
4.70 (m, 1H, CHH0), 6.81 (m, 4H, ArH), 7.13 (d, J = 9.0 Hz, 1H, ArH),
7.19 (m, 1H, ArH), 7.56 (m, 4H, ArH), 11.33 (br, 1H, NH+); Anal.
Calcd for C34H36ClF2N2O5ꢂHClꢂ1½H2O (654.1) requires C, 62.37; H,
6.11; N, 4.28; found C, 62.36; H, 6.18; N, 4.09; MS (+APCI) m/z
591 (3.7) [M+H]+ (calcd for C34H37F2N2O5 591.6 [M+H]+).
5.3.16. 5-Benzoyl-2-{3-[3-fluoro-5-(4-methoxytetrahydro-4H-4-
pyranyl)phenoxy]propyl}-2,3,4,5-tetrahydro-1H-pyrido[4,3-
b]indole hydrochloride (31)
5.3.19. 5-(4-Fluorobenzoyl)-2-{3-[3-fluoro-5-(4-methoxytet-
rahydro-4H-4-pyranyl)phenoxy]propyl}-8-methoxy-2,3,4,5-
tetrahydro-1H-pyrido[4,3-b]indole hydrochloride (34)
Following general procedure for benzoylation and benzylation,
NaH (15 mg, 0.4 mmol, 1.0 equiv), 2-{3-[3-fluoro-5-(4-methoxy-
tetrahydro-4H-4-pyranyl)phenoxy]propyl}-2,3,4,5-tetrahy-dro-1H-
pyrido[4,3-b]indole (28) (160 mg, 0.4 mmol, 1.0 equiv), benzoyl
Following general procedure for benzoylation and benzylation,
NaH (50 mg, 1.1 mmol, 1.0 equiv), 2-{3-[3-fluoro-5-(4-methoxy-
tetrahydro-4H-4-pyranyl)phenoxy]propyl}-8-methoxy-2,3,4,5-tet-
rahydro-1H-pyrido[4,3-b]indole
1.0 equiv), 4-fluorobenzoyl chloride (128
and HCl–iPrOH (20 L, 0.1 mmol) gave the product. Column eluent
(26)
(500 mg,
1.1 mmol,
chloride (43
lL, 0.4 mmol, 1.0 equiv) and HCl–iPrOH (34
lL,
lL, 1.1 mmol, 1.0 equiv)
0.2 mmol, 1.0 equiv) gave the product. Column eluent (DCM/
EtOAc, 50/50). Yield 48%; mp 174 °C (from DCM/Et2O, 50/50); light
brown crystals; TLC Rf 0.78 (DCM/MeOH, 90/10); IR cmꢁ1: 2976,
1685; 1H NMR (CDCl3) d: 1.92 (m, 4H, 2CH2), 2.64 (m, 2H, CH2),
2.99 (s, 3H, CH3), 3.25 (m, 1H, CHH0), 3.45 (m, 2H, CH2), 3.58 (m,
1H, CHH0), 3.71 (m, 1H, CHH0), 3.82 (m, 4H, 2CH2), 3.86 (m, 1H,
CHH0), 4.14 (m, 2H, CH2), 4.23 (m, 1H, CHH0), 4.82 (m, 1H, CHH0),
6.51 (ddd, J = 10.0 Hz, J = 2.0 Hz, J = 2.0 Hz, 1H, ArH), 6.71 (m, 1H,
ArH), 6.73 (d, J = 2.0 Hz, 1H, ArH), 7.12–7.72 (m, 9H, ArH), 13.35
(br, 1H, NH+); HPLC (Kromasil C18, H2O/MeOH/TFA (26:74:0.1),
k = 220 nm) rt.: 7.6 min (90%); Anal. Calcd for C33H35FN2O3ꢂ
HClꢂ13 4H2O (609.5): C, 64.97; H, 6.19; N, 4.59. Found: C, 64.93;
H, 6.15; N, 4.85 (the degradation of the product was observed dur-
ing the analysis); MS (+APCI) m/z 543 (3.6) [M+H]+ (calcd for
C33H36FN2O4 543.6 [M+H]+).
l
(EtOAc/EtOH, 90/10). Yield 11%; mp 177 °C (from iPrOH); light
brown crystals; TLC Rf 0.69 (AcOEt/EtOH, 90/10); IR cmꢁ1: 2946,
1679; 1H NMR (CDCl3) d: 1.88 (m, 4H, 2CH2), 2.35 (m, 2H, CH2),
2.82 (m, 1H, CHH0), 2.91 (s, 3H, CH3), 3.09 (m, 1H, CHH0), 3.37 (m,
1H, CHH0), 3.44 (m, 2H, CH2), 3.68 (m, 4H, 2CH2), 3.76 (m, 1H,
CHH0), 3.80 (s, 3H, CH3), 4.16 (m, 2H, CH2), 4.33 (m, 1H, CHH0),
4.75 (m, 1H, CHH0), 5.72 (br, 1H, NH+), 6.82 (m, 4H, ArH), 7.18 (d,
J = 9.0 Hz, 1H, ArH), 7.19 (d, J = 2.0 Hz, 1H, ArH), 7.44 (dd,
J = 8.5 Hz, J = 8.5 Hz, 2H, ArH), 7.72 (dd, J = 8.5 Hz, J = 5.0 Hz, 2H,
ArH); Anal. Calcd for C34H36F2N2O5ꢂHClꢂ1/2H2O (636.1): C, 64.23;
H, 5.82; N, 4.41. Found: C, 64.05; H, 6.13; N, 4.51; MS (+APCI) m/
z 591 (3.7) [M+H]+ (calcd for C34H37F2N2O5 591.6 [M+H]+).
5.3.20. 5-(4-Chlorobenzoyl)-2-{3-[3-fluoro-5-(4-methoxytet-
rahydro-4H-4-pyranyl)phenoxy]propyl}-8-methoxy-2,3,4,5-
tetrahydro-1H-pyrido[4,3-b]indole hydrochloride (35)
Following general procedure for benzoylation and benzylation,
NaH (85 mg, 2.1 mmol, 1.0 equiv), 2-{3-[3-fluoro-5-(4-methoxy-
tetrahydro-4H-4-pyranyl)phenoxy]propyl}-8-methoxy-2,3,4,5-tet-
rahydro-1H-pyrido[4,3-b]indole (26) (1.0 g, 2.1 mmol, 1.0 equiv),
5.3.17. 5-(2-Fluorobenzoyl)-2-{3-[3-fluoro-5-(4-methoxy-
tetrahydro-4H-4-pyranyl)phenoxy]propyl}-8-methoxy-2,3,4,5-
tetrahydro-1H-pyrido[4,3-b]indole hydrochloride (32)
Following general procedure for benzoylation and benzylation,
NaH (77 mg, 1.7 mmol, 1.0 equiv), 2-{3-[3-fluoro-5-(4-methoxytet-
rahydro-4H-4-pyranyl)phenoxy]propyl}-8-methoxy-2,3,4,5-tetra-
hydro-1H-pyrido[4,3-b]indole (26) (800 mg, 1.7 mmol, 1.0 equiv),
4-chlorobenzoyl chloride (271
lL, 2.1 mmol, 1.0 equiv) and HCl–
iPrOH (135 L, 0.7 mmol) gave the product. Column eluent
l
2-fluorobenzoyl chloride (205
l
L, 1.7 mmol, 1.0 equiv) and HCl–
(DCM/MeOH, 99/1). Yield 33%; mp 172 °C (from DCM/cyclohexane
50/50); light brown crystals; TLC Rf 0.67 (DCM/MeOH, 90/10); IR
cmꢁ1: 2948, 1681; 1H NMR (CDCl3) d: 1.93 (m, 4H, 2CH2), 2.60
(m, 2H, 2CH2), 2.90 (m, 1H, CHH0), 2.98 (s, 3H, CH3), 3.16 (m, 1H,
CHH0), 3.42 (m, 2H, CH2), 3.60 (m, 1H, CHH0), 3.65 (m, 4H, 2CH2),
3.83 (s, 3H, CH3), 3.90 (m, 1H, CHH0), 4.07 (m, 2H, CH2), 4.20 (m,
1H, CHH0), 4.78 (m, 1H, CHH0), 6.50 (d, J = 9.0 Hz, 1H, ArH), 6.73
(m, 3H, ArH), 6.83 (m, 1H, ArH), 6.92 (d, J = 9.0 Hz, ArH), 7.51 (d,
J = 8.0 Hz, ArH), 7.67 (d, J = 8.0 Hz, ArH), 13.24 (br, 1H, NH+); Anal.
Calcd for C34H36ClFN2O5ꢂHClꢂ1½H2O (670.5): C, 60.84; H, 5.96; N,
4.17. Found: C, 60.95; H, 5.99; N, 4.37; MS (+APCI) m/z 607 (3.8)
[M], 609 (3.8) [M+2] (calcd for C34H36ClFN2O5 607.1 [M]).
iPrOH (136 L, 0.3 mmol) gave the product. Column eluent (DCM/
l
EtOAc, 60/40). Yield 16%; mp >230 °C (from iPrOH); white crystals;
TLC Rf 0.81 (EtOAc/EtOH, 80/20); IR cmꢁ1: 2930, 1676; 1H NMR
(DMSO-d6) d: 1.87 (m, 4H, 2CH2), 2.31 (m, 2H, CH2), (m, 1H, CHH0),
2.90 (s, 3H, CH3), 2.97 (m, 1H, CHH0), 3.42 (m, 2H, CH2), 3.65 (m, 1H,
CHH0), 3.66 (m, 4H, 2CH2), 3.75 (m, 1H, CHH0), 3.79 (s, 3H, CH3), 4.15
(m, 2H, CH2), 4.33 (m, 1H, CHH0), 4.71 (m, 1H, CHH0), 6.82 (m, 3H,
ArH), 6.85 (dd, J = 9.0 Hz, J = 2.5 Hz, 1H, ArH), 7.19 (m, 2H, ArH),
7.46 (m, 2H, ArH), 7.73 (m, 2H, ArH), 10.72 (br, 1H, NH+); Anal. Calcd
for C34H36F2N2O5ꢂHClꢂH2O (645.1): C, 63.03; H, 6.09; N, 4.34. Found:
C, 63.21; H, 6.11; N, 4.32; MS (+APCI) m/z 591 (3.7) [M+H]+ (calcd
for C34H37F2N2O5 591.6 [M+H]+).
5.3.21. 2-{3-[3-Fluoro-5-(4-methoxytetrahydro-4H-4-pyranyl)
phenoxy]propyl}-8-methoxy-5-(2,4,6-trichlorobenzoyl)-2,3,4,5-
tetrahydro-1H-pyrido[4,3-b]indole hydrochloride (36)
Following general procedure for benzoylation and benzylation,
NaH (85 mg, 2.1 mmol, 1.0 equiv), 2-{3-[3-fluoro-5-(4-methoxy-
tetrahydro-4H-4-pyranyl)phenoxy]propyl}-8-methoxy-2,3,4,5-tet-
rahydro-1H-pyrido[4,3-b]indole (26) (1.0 g, 2.1 mmol, 1.0 equiv),
5.3.18. 5-(3-Fluorobenzoyl)-2-{3-[3-fluoro-5-(4-methoxy
tetrahydro-4H-4-pyranyl)phenoxy]propyl}-8-methoxy-2,3,4,5-
tetrahydro-1H-pyrido[4,3-b]indole hydrochloride (33)
Following general procedure for benzoylation and benzylation,
NaH (70 mg, 1.7 mmol, 1.0 equiv), 2-{3-[3-fluoro-5-(4-methoxy-
tetrahydro-4H-4-pyranyl)phenoxy]propyl}-8-methoxy-2,3,4,5-tet-
rahydro-1H-pyrido[4,3-b]indole
(26)
(800 mg,
1.7 mmol,
2,4,6-trichlorobenzoyl chloride (667 lL, 4.3 mmol, 2.0 equiv) and

3922
A. Bridoux et al. / Bioorg. Med. Chem. 18 (2010) 3910–3924
HCl–iPrOH (210
l
L, 1.0 mmol) gave the product. Column eluent
1.0 equiv) and HCl–iPrOH (78
umn eluent (DCM/EtOAc, 20/80). Yield 36%; mp >230 °C (from
EtOH); white crystals; TLC Rf 0.53 (EtOAc/EtOH, 80/20); IR cmꢁ1
lL, 0.4 mmol) gave the product. Col-
(DCM/EtOAc, 80/20). Yield 50%; mp >230 °C (from iPrOH); light
brown crystals; TLC Rf 0.80 (EtOAc/EtOH, 90/10); IR cmꢁ1: 2954,
1700; 1H NMR (DMSO-d6) d: 1.86 (m, 4H, 2CH2), 2.30 (m, 2H,
2CH2), 2.70 (m, 1H, CHH0), 2.89 (s, 3H, CH3), 3.17 (m, 1H, CHH0),
3.59 (m, 2H, CH2), 3.67 (m, 4H, 2CH2), 3.76 (m, 2H, CH2), 3.83 (s,
3H, CH3), 4.15 (m, 2H, CH2), 4.36 (m, 1H, CHH0), 4.67 (m, 1H, CHH0),
6.77 (m, 3H, ArH), 7.05 (d, J = 9.0 Hz, 1H, ArH), 7.22 (m, 1H, ArH),
7.99 (d, J = 2.0 Hz, 1H, ArH), 8.05 (d, J = 1.5 Hz, 1H, ArH), 8.39 (d,
J = 9.0 Hz, 1H, ArH), 11.19 (br, 1H, NH+); Anal. Calcd for
C34H34Cl3FN2O5ꢂHClꢂ1/2H2O (721.4): C, 56.55; H, 4.71; N, 3.88.
Found: C, 56.50; H, 4.97; N, 3.93; MS (+APCI) m/z 675 (3.9) [M],
677 (3.9) [M+2] (calcd for C34H34Cl3FN2O5 676.0 [M]).
:
2954, 1310, 1146; 1H NMR (DMSO-d6) d: 1.86 (m, 4H, 2CH2),
2.27 (m, 2H, CH2), 2.72 (m, 1H, CHH0), 2.89 (s, 3H, CH3), 3.09 (m,
1H, CHH0), 3.17 (s, 3H, CH3), 3.45 (m, 2H, CH2), 3.46 (m, 1H, CHH0),
3.67 (m, 4H, 2CH2), 3.76 (s, 3H, CH3), 3.87 (m, 1H, CHH0), 4.14 (t,
J = 5.0 Hz, 2H, CH2), 4.33 (m, 1H, CHH0), 4.75 (m, 1H, CHH0), 5.52
(q, JAB = 17.5 Hz, 2H, CH2), 6.78 (m, 4H, ArH), 7.09 (d, J = 2.0 Hz,
1H, ArH), 7.27 (d, J = 8.0 Hz, 2H, ArH), 7.37 (d, J = 9.0 Hz, 1H,
ArH), 7.85 (d, J = 8.0 Hz, 2H, ArH), 10.10 (br, 1H, NH+); Anal. Calcd
for C35H41FN2O6SꢂHClꢂH2O (691.2): C, 60.81; H, 6.42; N, 4.05.
Found: C, 60.45; H, 6.32; N, 3.94; MS (+APCI) m/z 637 (3.5)
[M+H]+ (calcd for C35H42FN2O6S 637.7 [M+H]+).
5.3.22. 5-(4-Bromobenzoyl)-2-{3-[3-fluoro-5-(4-methoxytet-
rahydro-4H-4-pyranyl)phenoxy]propyl}-8-methoxy-2,3,4,5-
tetrahydro-1H-pyrido[4,3-b]indole hydrochloride (37)
Following general procedure for benzoylation and benzylation,
NaH (60 mg, 1.3 mmol, 1.0 equiv), 2-{3-[3-fluoro-5-(4-methoxy-
tetrahydro-4H-4-pyranyl)phenoxy]propyl}-8-methoxy-2,3,4,5-tet-
rahydro-1H-pyrido[4,3-b]indole (26) (600 mg, 1.3 mmol, 1.0
equiv), 4-bromobenzoyl chloride (281 mg, 1.3 mmol, 1.0 equiv)
5.3.25. 8-Fluoro-2-{3-[3-fluoro-5-(4-methoxytetrahydro-4H-4-
pyranyl)phenoxy]propyl}-5-(4-methanesulfonylbenzyl)-2,3,4,5-
tetrahydro-1H-pyrido[4,3-b]indole hydrochloride (40)
Following general procedure for benzoylation and benzylation,
NaH (42 mg, 1.1 mmol, 1.0 equiv), 2-{3-[3-fluoro-5-(4-methoxy-
tetrahydro-4H-4-pyranyl)phenoxy]propyl}-8-fluoro-2,3,4,5-tetra-
hydro-1H-pyrido[4,3-b]indole (27) (500 mg, 1.1 mmol, 1.0 equiv),
4-methanesulfonylbenzyl bromide (259 mg, 1.1 mmol, 1.0 equiv)
and HCl–iPrOH (60 lL, 0.3 mmol) gave the product. Column eluent
(DCM/EtOAc, 10/90). Yield 20%; mp 165 °C (from iPrOH); white
crystals; TLC Rf 0.53 (EtOAc/EtOH, 90/10); IR cmꢁ1: 2954, 1700;
1H NMR (DMSO-d6) d: 1.88 (m, 4H, 2CH2), 2.35 (m, 2H, CH2), 2.81
(m, 1H, CHH0), 2.81 (s, 3H, CH3), 3.10 (m, 1H, CHH0), 3.30 (m, 1H,
CHH0), 3.37 (m, 2H, CH2), 3.64 (m, 4H, 2CH2), 3.90 (m, 1H, CHH0),
3.80 (s, 3H, CH3), 4.16 (m, 2H, CH2), 4.33 (m, 1H, CHH0), 4.71 (m,
1H, CHH0), 6.81 (m, 4H, ArH), 7.16 (m, 2H, ArH), 7.62 (d,
J = 8.0 Hz, 2H, ArH), 7.81 (d, J = 8.0 Hz, 2H, ArH), 11.32 (br, 1H,
NH+); Anal. Calcd for C34H36BrFN2O5ꢂHClꢂ1/2H2O (697.0): C,
58.53; H, 5.16; N, 4.01. Found: C, 58.60; H, 5.42; N, 4.22; MS
(+APCI) m/z 651 (3.8) [M], 653 (3.8) [M+2] (calcd for
C34H36BrFN2O5 651.5 [M]).
and HCl–iPrOH (62 lL, 0.3 mmol) gave the product. Column eluent
(EtOAc/EtOH, 95/5). Yield 30%; mp >230 °C (from EtOH); white
crystals; TLC Rf 0.37 (EtOAc/EtOH, 80/20); IR cmꢁ1: 1306, 1149,
1070; 1H NMR (DMSO-d6) d: 1.86 (m, 4H, 2CH2), 2.29 (m, 2H,
CH2), 2.72 (m, 1H, CHH0), 2.89 (s, 3H, CH3), 3.12 (m, 1H, CHH0),
3.17 (s, 3H, CH3), 3.44 (m, 2H, CH2), 3.63 (m, 1H, CHH0), 3.66 (m,
4H, 2CH2), 3.88 (m, 1H, CHH0), 4.15 (m, 2H, CH2), 4.33 (m, 1H,
CHH0), 4.75 (m, 1H, CHH0), 5.57 (q, JAB = 17.0 Hz, 2H, CH2), 6.77
(m, 3H, ArH), 7.01 (dd, J = 9.0 Hz, J = 8.5 Hz, 1H, ArH), 7.28 (d,
J = 8.0 Hz, 2H, ArH), 7.38 (dd, J = 10.0 Hz, J = 2.5 Hz, 1H, ArH), 7.50
(dd, J = 8.5 Hz, J = 4.0 Hz, 1H, ArH), 7.86 (d, J = 8.0 Hz, 2H, ArH),
10.31 (br, 1H, NH+); Anal. Calcd for C34H38F2N2O5SꢂHClꢂH2O
(679.2): C, 61.76; H, 5.95; N, 4.24. Found: C, 61.54; H, 6.11; N,
4.12; MS (+APCI) m/z 625 (3.4) [M+H]+ (calcd for C34H39F2N2O5S
625.7 [M+H]+).
5.3.23. 5-(4-Dimethylaminomethylenaminosulfonylbenzoyl)-2-
{3-[3-fluoro-5-(4-methoxytetrahydro-4H-4-pyranyl)phenoxy]
propyl}-8-methoxy-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole
hydrochloride (38)
Following general procedure for benzoylation and benzylation,
NaH (68 mg, 1.7 mmol, 1.0 equiv), 2-{3-[3-fluoro-5-(4-methoxytet-
rahydro-4H-4-pyranyl)phenoxy]propyl}-8-methoxy-2,3,4,5-tetra-
hydro-1H-pyrido[4,3-b]indole (26) (800 mg, 1.7 mmol, 1.0 equiv),
4-sulfaminobenzoyl chloride–DMF complex (750 mg, 2.6 mmol,
5.3.26. 5-Benzoyl-2-{3-[3-fluoro-5-(4-methoxytetrahydro-4H-4-
pyranyl)phenoxy]propyl}-8-methanesulfonyl-2,3,4,5-tetra-
hydro-1H-pyrido[4,3-b]indole hydrochloride (41)
To a stirred suspension of 4-dimethylaminopyridine (90 mg,
0.7 mmol, 1.0 equiv) at 0 °C in DMF (5 mL) was added slowly an
anhydride solution of 2-{3-[3-fluoro-5-(4-methoxytetrahydro-4H-
4-pyranyl)phenoxy]propyl}-8-methanesulfonyl-2,3,4,5-tetrahydro-
1H-pyrido[4,3-b]indole (29) (380 mg, 0.7 mmol, 1.0 equiv) dis-
solved in DMF (5 mL). NaH (60% dispersion in mineral oil, 30 mg,
0.7 mmol, 1.0 equiv) was added portionwise and the medium
was stirred for 2 h at 0 °C. Then benzoyl chloride derivative
1.5 equiv) and HCl–iPrOH (85 lL, 0.4 mmol) gave the product. Col-
umn eluent (EtOAc/EtOH, 90/10). Yield 24%; mp >230 °C; light
brown powder; TLC Rf 0.36 (EtOAc/EtOH, 90/10); IR cmꢁ1: 1625,
1340, 1149; 1H NMR (DMSO-d6) d: 1.88 (m, 4H, 2CH2), 2.34 (m,
2H, CH2), 2.83 (m, 1H, CHH0), 2.92 (s, 3H, CH3), 2.96 (s, 3H, CH3),
3.05 (m, 1H, CHH0), 3.19 (s, 3H, CH3), 3.32 (m, 1H, CHH0), 3.38 (m,
4H, 2CH2), 3.44 (m, 2H, CH2), 3.76 (m, 1H, CHH0), 3.81 (s, 3H,
CH3), 4.16 (m, 2H, CH2), 4.32 (m, 1H, CHH0), 4.73 (m, 1H, CHH0),
6.80 (m, 3H, ArH), 6.54 (d, J = 9.5 Hz, 1H, ArH), 7.19 (m, 2H, ArH),
7.82 (d, J = 8.0 Hz, 2H, ArH), 7.97 (d, J = 8.0 Hz, 2H, ArH), 8.30 (s,
1H, CH2), 11.09 (br, 1H, NH+); MS (+APCI) m/z 707 (3.4) [M+H]+
(calcd for C37H44FN4O7S 707.8 [M+H]+).
(171 lL, 1.5 mmol, 2.0 equiv) was added dropwise at 0 °C. The
reaction medium was stirred during 2 h at rt, filtered and the fil-
trate was evaporated. The residual oil was then diluted in EtOAc
(10 mL). The solution was added dropwise to a 10% K2CO3 aqueous
solution (15 mL) and was allowed to precipitate during the night.
The organic product was extracted with EtOAc (3 ꢀ 15 mL). The or-
ganic phase was dried over MgSO4 and evaporated. The crude
product was purified by column chromatography (230–400 mesh)
over silica gel using the solvent for chromatography (EtOAc) to give
a solution which was filtered and evaporated. The residue was then
diluted in CHCl3 (5 mL) and transformed to a hydrochloride using a
5.3.24. 2-{3-[3-Fluoro-5-(4-methoxytetrahydro-4H-4-pyranyl)
phenoxy]propyl}-5-(4-methanesulfonylbenzyl)-8-methoxy-
2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole hydrochloride (39)
Following general procedure for benzoylation and benzylation,
NaH (43 mg, 1.1 mmol, 1.0 equiv), 2-{3-[3-fluoro-5-(4-methoxy-
tetrahydro-4H-4-pyranyl)phenoxy]propyl}-8-methoxy-2,3,4,5-tet-
solution of HCl in iPrOH (5–6 M) (10 lL, 0.3 mmol). The solution
was evaporated in vacuo and the residue was sonicated in Et2O
(25 mL) to give the title compound as a solid which was filtered
and dried over P2O5. Yield 31%; mp 183 °C (from MeCN); white
crystals; TLC Rf 0.49 (EtOAc/EtOH, 90/10); IR cmꢁ1: 3441, 1695,
rahydro-1H-pyrido[4,3-b]indole
(26)
(500 mg,
1.1 mmol,
1.0 equiv), 4-methanesulfonylbenzyl bromide (266 mg, 1.1 mmol,

A. Bridoux et al. / Bioorg. Med. Chem. 18 (2010) 3910–3924
3923
1303, 1140; 1H NMR (DMSO-d6) d: 1.95 (m, 4H, 2CH2), 2.13 (m, 2H,
CH2), 2.81 (m, 6H, 3CH2), 3.01 (s, 3H, CH3), 3.10 (s, 3H, CH3), 3.77
(m, 1H, CHH0), 3.82 (m, 4H, 2CH2), 4.09 (t, J = 6.0 Hz, 2H, CH2),
6.58 (ddd, J = 10.5 Hz, J = 2.0 Hz, J = 2.0 Hz, 1H, ArH), 6.71 (ddd,
J = 10.0 Hz, J = 2.0 Hz, J = 2.0 Hz, 1H, ArH), 6.75 (dd, J = 2.0 Hz,
J = 2.0 Hz, 1H, ArH), 7.50 (m, 3H, ArH), 7.67 (m, 4H, ArH), 8.03 (d,
J = 1.5 Hz, 1H, ArH); Anal. Calcd for C34H37FN2O6SꢂHClꢂH2O
(675.2): C, 60.48; H, 5.97; N, 4.15. Found: C, 60.50; H, 5.95; N,
4.13; MS (+APCI) m/z 621 (3.2) [M+H]+, 589 (3.2) [M+HꢁMeOH]+
(calcd for C34H38FN2O6S 621.7 [M+H]+).
including Goldscore and Xscore as well as a visual inspection of
the coherency of the docking results.38 Therefore, the chosen con-
formation was the best scored one.
SYBYL 6.9.1—Molecular modelling software 2001, Tripos Inc.,
1699 South Hanley Road, St. Louis, MO 63144-2913, USA.
Acknowledgements
This study has been part of the Ph.D. thesis defended by Dr.
Alexandre BRIDOUX on 11/04/2005. The authors would like to
thank Ms. Amélie LEMOINE (Institut de Chimie Pharmaceutique Al-
bert Lespagnol) for her technical assistance in this study, Mrs. Fabi-
enne BRIDOUX for editing this manuscript and her availability. The
molecular modelling studies have been achieved at the Laboratoire
de Chimie Thérapeutique, Faculté des Sciences Pharmaceutiques et
Biologiques de Lille. This study has been funded by the Institut de
Chimie Pharmaceutique Albert Lespagnol.
5.4. Biological tests
5.4.1. Analysis of arachidonic metabolites by high-performance
liquid chromatography
Human peripheral venous blood samples were taken from
healthy volunteers and collected into heparinised tubes. Aliquots
were then transferred to tubes containing either the vehicle
(DMSO) or the test compounds and incubated for 15 min at 37 °C
under continuous agitation. A23187 (40.0 mM) alone or in combi-
nation with LPS (500 mg) was then added and incubation contin-
ued for either 30 min in the case of A23187 alone, or 24 h for
samples stimulated with A23187 + LPS. Eicosanoids were extracted
from the samples into EtOAc. Samples were then evaporated to
dryness under nitrogen, re-suspended in the mobile phase to pre-
cipitate the proteins and then centrifuged. The supernatant was
then directly analysed by HPLC using Hypersil ODS 3 mM columns
(12.5 ꢀ 0.46 mm), a MeOH/H2O/AcOH (80:20:0.1) mobile phase at
a flow rate of 1 mL/min and UV detection firstly at 270 nm and
12 min later at 245 nm. Eicosanoids were separated on the follow-
ing gradients: 70–80% MeOH for 10 min, 100% MeOH on 19 min for
5 min and 70% MeOH for 7 min.36
Supplementary data
Supplementary data (the structure of the internal standard used
during the HWB analyses was added) associated with this article
can be found, in the online version, at doi:10.1016/j.bmc.
2010.04.034.
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