Novel 5-azaindolocarbazoles as cytotoxic agents and Chk1 inhibitors

Article abstract of DOI:10.1016/j.bmc.2008.02.086

We describe here an efficient synthesis of new 5-azaindolocarbazoles designed for cytotoxic and Chk1 inhibiting properties. The synthesis of 'symmetrical' and 'dissymmetrical' structures is discussed. Concerning the dissymmetrical 5-azaindolocarbazoles derivatives, with both an indole moiety and a 5-azaindole moiety, the synthesis was achieved using two very efficient key steps. The first one is a Stille reaction with a 3-trimethylstannyl-5-azaindole derivative and the second one a photochemical step leading to the proposed polycyclic structure. Various pharmacomodulations were performed to investigate the structure-activity relationships (SAR). Several substituents such as OBn, OH, and methylenedioxy groups were successfully introduced on the indole moiety of the 5-azaindolocarbazole. Compounds with or without substituents on the nitrogen atom of the maleimide were prepared, as well as derivatives with glucopyranosyl substituent on the nitrogen atom of the indole moiety. The cytotoxicity of these new compounds was evaluated on two cell lines (L1210, HT29). Several compounds showed cytotoxicity in the sub-micromolar range. Among the most cytototoxic was the 1,3-dioxolo[4,5-b]-6-(2-dimethylaminoethyl)-1H-pyrido[3′,4′:4,5]pyrrolo[3,2-i]pyrrolo[3,4-g]carbazole-5,7(6H,12H)-dione (35, IC₅₀ = 195 nM on L1210). The compounds were also investigated for their Chk1 inhibiting activity. Compounds without any substitution on the maleimide moiety were the most potent. This is the case of compounds 45-47 with IC₅₀ of, respectively, 72, 27, and 14 nM toward Chk1. Compound 46, which exhibits moderate cytotoxicity, appears to be a good candidate for development in a multi-drug anticancer therapy.

Full text of DOI:10.1016/j.bmc.2008.02.086

Available online at www.sciencedirect.com
Bioorganic & Medicinal Chemistry 16 (2008) 5303–5321
Novel 5-azaindolocarbazoles as cytotoxic agents
and Chk1 inhibitors
a
a,
a
b
*
´
Myriam Lefoix, Gerard Coudert, Sylvain Routier, Bruno Pfeiffer,
b
b
b
b
´
Daniel-Henri Caignard, John Hickman, Alain Pierre, Roy M. Golsteyn,
b
b
a,
*
´
´
´
´
Stephane Leonce, Celine Bossard and Jean-Yves Merour
aInstitut de Chimie Organique et Analytique, Universite´ d’Orle´ans, UMR CNRS 6005, Rue de Chartres,
BP 6759, 45067 Orle´ans Cedex 2, France
bInstitut de Recherches SERVIER, Division Recherche Cance´rologie, 125 Chemin de Ronde, 78290 Croissy sur Seine, France
Received 12 November 2007; revised 25 February 2008; accepted 28 February 2008
Available online 4 March 2008
Abstract—We describe here an efficient synthesis of new 5-azaindolocarbazoles designed for cytotoxic and Chk1 inhibiting proper-
ties. The synthesis of ‘symmetrical’ and ‘dissymmetrical’ structures is discussed. Concerning the dissymmetrical 5-azaindolocarbaz-
oles derivatives, with both an indole moiety and a 5-azaindole moiety, the synthesis was achieved using two very efficient key steps.
The first one is a Stille reaction with a 3-trimethylstannyl-5-azaindole derivative and the second one a photochemical step leading to
the proposed polycyclic structure. Various pharmacomodulations were performed to investigate the structure–activity relationships
(SAR). Several substituents such as OBn, OH, and methylenedioxy groups were successfully introduced on the indole moiety of the
5-azaindolocarbazole. Compounds with or without substituents on the nitrogen atom of the maleimide were prepared, as well as
derivatives with glucopyranosyl substituent on the nitrogen atom of the indole moiety. The cytotoxicity of these new compounds
was evaluated on two cell lines (L1210, HT29). Several compounds showed cytotoxicity in the sub-micromolar range. Among
the most cytototoxic was the 1,3-dioxolo[4,5-b]-6-(2-dimethylaminoethyl)-1H-pyrido[30,40:4,5]pyrrolo[3,2-i]pyrrolo[3,4-g]carba-
zole-5,7(6H,12H)-dione (35, IC50 = 195 nM on L1210). The compounds were also investigated for their Chk1 inhibiting activity.
Compounds without any substitution on the maleimide moiety were the most potent. This is the case of compounds 45–47 with
IC50 of, respectively, 72, 27, and 14 nM toward Chk1. Compound 46, which exhibits moderate cytotoxicity, appears to be a good
candidate for development in a multi-drug anticancer therapy.
ꢀ 2008 Elsevier Ltd. All rights reserved.
1. Introduction
class of compounds with potent antitumor properties
due to inhibition of topoisomerase and/or strong
cytotoxicity.2,3
The cell division cycle is controlled by various protein
kinases such as CDKs, Aurora or checkpoint kinases.
The importance of kinase pathways is highlighted by
observations that genes encoding kinases are sometimes
mutated or overexpressed in human tumors.1 In the
search for new anticancer agents, intensive efforts have
been developed to find novel inhibitors of CDKs and
more generally of protein kinases that regulate cell cycle
and apoptosis. In this field, indolo[2,3-a]pyrrolo[3,4-
These compounds have also attracted considerable
attention because of their ability to inhibit protein ki-
nases.4–6 The structure–activity relationships (SARs) of
indolocarbazole series have been extensively studied as
topoisomerase I inhibitors.2,7 For example, compounds
such as NB-506 and J-107088 (also known as Edoteca-
rin, Fig. 1) have entered into clinical trials for cancer
treatment.8 More recently, it was published that the
members of the CDKs9 family can be inhibited by indo-
locarbazoles (see Fig. 2).
c]carbazole alkaloids (indolocarbazoles) form
a
Keywords: 5-Azaindole; 5-Azaindolocarbazole; Chk1 inhibitors;
Cytoxicity.
We have recently described the bioisosteric replacement
of an indole moiety of arcyriaflavin10,11 skeleton by a
7-azaindole unit affording the first symmetrical and
*
Corresponding authors. Tel.: +33 2 384589; fax: +33 2 38417281;
e-mail addresses: gerard.coudert@univ-orleans.fr; jean-yves.
merour@univ-orleans.fr
0968-0896/$ - see front matter ꢀ 2008 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2008.02.086

5304
M. Lefoix et al. / Bioorg. Med. Chem. 16 (2008) 5303–5321
R
isogranulatimide. This compound can be, to some
H
HN
extent, considered as a bioisostere of indolocarbazole,
by the replacement of one of the two indole moities by
an imidazole ring. In the continuation of our previous
work on 7-azaindolocarbazoles, we postulated that the
replacement of the 7-azaindole moiety by the more basic
5-azaindole moiety could be of interest. In this paper, we
described the synthesis of new 5-azaindolocarbazole
derivatives III. These compounds were investigated
in vitro for both their cytotoxicity on L1210 and
HT29 cancer cell lines, and their inhibiting activity on
Chk1 kinases. The SAR were investigated by adding
various substituents on the indole ring, and/or the malei-
mide moiety.
N
O
N
N
O
R
O
OH
N
H
N
N
O
H
HO
H3C
OH
O
HO
MeO
NB 506 R = CHO
J 107088 R = CH (CH2OH)2
NHCH3
HO
OH
Stauroporine R = H
UCN-01 R = OH
Figure 1. Glycosylated indolocarbazoles.
2. Chemistry
H3C
H
N
O
O
The first synthetic pathway envisaged to prepare the
5-azaindolocarbazoles of type III (Scheme 1) was de-
rived from the one we had previously used for the syn-
thesis of the 7-azaindolocarbazoles approach, and
implies the preparation of bis-arylmaleimides followed
by a central ring closure in 5-azaindolocarbazoles. The
first step consists in a regioselective Michael addition
of 5-azaindole 1 in position C-3 under basic media.12,13
N
O
O
N
N
H
N
H
X
N
H
N
H
I
X = CH
Arcyriaflavin -A
II X = N
R1
H
N
O
N
O
2.1. Synthesis of bis-substituted maleimide compounds
O
O
N
Our first attempt was to prepare compound 2 by react-
ing the 5-azaindole 1 with the N-methyl dibromomalei-
mide 11 in the presence of EtMgBr in a mixture of
toluene and dichloromethane30–34 but only the degrada-
tion of the reaction mixture was observed. No trace of
compound 2 was obtained even by changing the base
for LiHMDS or the solvent for THF as for indole it-
self.19 Interestingly, the bis-5-azaindole derivative 6,
resulting from a bis-N-alkylation,35 was obtained in a
low yield (29%) in refluxing toluene instead of expected
compounds 2 or even 3 (Scheme 2). This result stopped
our attempts to obtain the symmetrical 5-azaderivative 3
(X = N) through this pathway.
N
X
N
N
N
N
R
H
H
Isogranulatimide
5-azaindolocarbazoles
III X = N or CH
Figure 2. Aglycones indolocarbazoles derivatives and analogues.
dissymmetrical 7-azaindolocarbazoles I and II.12–14
Replacement of one of the two indoles moieties by other
aromatic units such as phenyl,15,16 pyridine,15,17 quino-
line or isoquinoline,15 indene,18 naphthalene19,20 led to
the identification of new and potent cyclin kinase inhib-
itors.21–23
We then focused our efforts on the synthesis of the dis-
symmetrical compound 4 (X = CH) by direct and regio-
selective reaction of the lithium salt of 5-azaindole 1 and
the easily prepared compound 7 (Scheme 3, Table 1).31
Compound 7 was prepared according to the literature
by protecting the indole nitrogen atom of compound 5
with a Boc group. All the anionic reactions were per-
formed at ꢀ30 ꢁC during 1 h and the temperature was
allowed to reach ꢀ20 ꢁC during 45 min after the addi-
tion of electrophile 7.
Previously, we have published a synthesis of some naph-
tho19,20 and benzocarbazole16 derivatives with strong
cytotoxicity and interesting CDK1 inhibiting activity.
Modification of the attachment of one indole unit such
as in indolo[6,7-a]pyrrolo[3,4-c]carbazoles22 or in arcyri-
acyanin A24 led to potent CDK4/Cyclin D1 inhibitors.
Chk1 plays a very important role in the cell cycle regu-
lation via the DNA damage checkpoint.27,28 Several gly-
cosylated compounds, such as UCN-01, are potent
Chk1 inhibitors.25 Crystallographic data on complexes
between Chk1 and indolocarbazole derivatives such as
staurosporine or UCN-01 have been published and the
interactions in the ATP pocket described.26
Whatever the conditions used, the overall yield of the
reaction remained low (38% in the best case, entry 1)
and the reaction appeared to be not regioselective in tolu-
ene, a mixture of N-alkylated compound 8 and C-alkyl-
ated derivative 9 being obtained (entries 1–2). The best
yield of 9 was obtained by using 2 equiv of 5-azaindole 1
with 4.2 equiv of LiHMDS (entry 3). Replacement of tol-
uene by THF led, in a low yield (11%, entry 5) to a regio-
selective N-alkylation leading to compound 8.
Recently, it has been reported that small natural mole-
cules such as granulatimide and isogranulatimide are
potent Chk1 inhibitors29 with nanomolar activities for

M. Lefoix et al. / Bioorg. Med. Chem. 16 (2008) 5303–5321
5305
N
N
H
N
O
O
1
Br
N
N
O
O
N
O
O
N
2
H
Br
Br
X
N
11
III
N
O
O
N
N
H
H
Br
3 X = N
4 X = CH
N
R
5 R = H
7 R = Boc
Scheme 1. Retrosynthetic scheme of 5-azaindolocarbazoles (V).
unable to increase the yield despite numerous efforts
(data not shown). Since this strategy was very efficient
in the 7-azaindole series,12,13 these results show dramatic
differences in the chemical behavior of the 5-azaindole
compounds compared to their counterpart in indole
and 7-azaindole series.
N
O
O
N
N
N
O
O
a
N
N
N
+
N
H
Br
Br
1
6
11
We then switched toward palladium catalyzed cross-
coupling reactions, using the Stille methodology in order
to obtain compound 3. First we prepared the 1-Boc-3-
trimethylstannyl-5-azaindole 10 from 1-Boc-7-azaindole
following our just recently described route.36 This stan-
nyl derivative 10 was then engaged in a Stille coupling
reaction with the dibromomaleimide 11 using various
experimental conditions (Scheme 4, Table 2).
N
O
O
Br
N
and not
N
H
2
Scheme 2. Reagents and conditions: (a) Compound 1 (3.0 equiv),
LiHMDS (6.6 equiv), toluene, rt, 1 h then 11 (1 equiv), reflux, 5 h,
29%.
All the reactions were performed with 5–10% mol of cat-
alyst, several additives (10–20% mol) and various sol-
vents. Most of the assays led to a rapid degradation of
the reaction mixture in the presence of copper (I) deriv-
atives. The results with LiCl addition were also disap-
Although it seems possible to obtain compound 9 by a
regioselective addition of the 5-azaindole on 7, we were
N
O
O
N
N
N
O
O
N
Boc
8
N
Base
Br
and/or
+
N
N
H
N
O
O
Boc
1
7
N
N
Boc
N
H
9
Scheme 3. Synthesis of 8 and/or 9 by lithiation of 5-azaindole 1. For conditions see Table 1.

5306
M. Lefoix et al. / Bioorg. Med. Chem. 16 (2008) 5303–5321
Table 1. Anionic reaction of compound 1 with compound 7 (1 equiv)a
Entry
Equivalent of 1
Solvent
Base (equiv)
Yield of 8
Yield of 9
1
2
3
4
5
1.0
1.2
2
Toluene
Toluene
Toluene
Toluene
THF
LiHMDS (1.0)
LiHMDS (2.5)
LiHMDS (4.2)
LiHMDS (4.2)
LiHMDS (2.5)
13%
10%
ND
ND
11%
25%
19%
25%
24%
ND
4
1.2
a The reaction was conducted in anoxic conditions.
N
O
O
Br
N
SnMe3
X
N
N
N
O
O
12
+ 11
Boc
a
N
Boc
N
N
N
+
10
N
N
N
Boc
6
13
Scheme 4. Stille reaction of compound 10 with dibromomaleimide 11.
Table 2. Conditions of Stille reaction of 10
Entry
Catalyst
Solvent
Temperature
Additives
Time (h)
Yields
13
12
10
6
1
2
3
4
5
Pd(PPh3)4
Idem
THF
DMF
Reflux
50 ꢁC
Reflux
CuBrÆMe2S
CuI, CsF
CuI
4
Degradation
Degradation
Degradation
1
PdCl2(PPh3)2
Idem
Idem
THF
Toluene
Toluene
1
95 ꢁC
Reflux
LiCl
LiCl
15
15
—
—
20%
11%
57%
68%
—
17%
pointing. We did not obtain the desired derivative 12
and instead we detected the hydrodestannylated com-
pound 13, with some starting material 10 and bis-5-aza-
indole maleimide 6. A possible explanation could be that
compound 10 is subjected to a hydrodestannylation fol-
lowed by the removal of the Boc protective group under
thermal conditions leading to 5-azaindole 1 that reacts
via a Michael addition with the dibromomaleimide 11.
Replacement of the Boc by other protective groups such
as benzenesulfonyl or MOM did not allow us to obtain
the expected compound 12.
First the monobromoindolylmaleimides 18,32 19,32 and
20 were obtained in good yields (79–88%) by reacting
the dibromomaleimide 11 with the lithium anion of in-
doles 15–17. The unsymmetrical maleimides derivatives
21–23 were then obtained in good yields (72–87%,
Scheme 6) via the Stille reaction.
2.2. Central ring closure and reaction on the maleimide
We tried first unsuccessfully (Scheme 7) to obtain the
5-azaindolocarbazole 3 by the treatment of compound
25 in the presence of trifluoroacetic acid according to
what was observed in the indole series.11,35,37 Com-
pound 25 was obtained in very good yield (98%) by
the removal of the Boc group of 14 in the presence of
formic acid at room temperature, followed by hydroge-
nation over palladium on carbon.
Another possibility, allowing only the preparation of the
dissymmetrical bis-5-azaindolemaleimide 14, was to
start from the monobromoindoylmaleimide 531 and the
stannyl derivative 10 (Scheme 5, Table 3). All reactions
were performed using 10% mol of catalyst and several
additives and the solvents were retested. The expected
compound 14 was obtained in 92% yield by using
Pd(PPh3)4 in the presence of CuBrÆMe2S (entry 5). Un-
der the same conditions, the use of the safer 3-tributyl-
stannyl-1-Boc-5-azaindole instead of 10, gave also 14
but in much more lower yield (36%).
This failure, probably due to the protonation of the pyr-
idine nitrogen atom, led us to try a photochemical oxi-
dative cyclization,12,19,23 (Scheme 8) despite the
following drawbacks: (i) it was difficult to perform on
large scale; (ii) it required high dilution minimizing
throughput; (iii) removal of the I2 by-products by
extractive workup was problematic due to the low insol-
ubility of the 5-azaindolocarbazole product. Com-
pounds 14, 21–23 were irradiated 30 min with a 500 W
This very efficient approach was then extended to the
5-benzyloxyindole 15, 6-benzyloxyindole 16 and 5,6-
methylenedioxyindole 17 (Scheme 6).

M. Lefoix et al. / Bioorg. Med. Chem. 16 (2008) 5303–5321
5307
N
N
O
O
O
O
SnMe3
Br
N
N
+
N
N
N
N
H
H
5
10
Boc
Boc
14
Scheme 5. Stille reaction of 5.
Table 3. Conditions of Stille reaction of 5a
Entry
Catalyst
Additives (equiv)
Solvent
Time
Yield of 14
1
2
3
4
5
PdCl2(PPh3)2
PdCl2(PPh3)2
PdCl2(PPh3)2
Pd2(dba)3
CuI (0.2)
CuI (0.1)
THF
THF
THF
5 h
31%
36%
Deg.
Deg.
92%
22 h
6 h
CuI (1.0) LiCl (1.0)
AsPh3 (0.4)
CuBr.Me2S (1.5)
Dioxane
THF
6 h
30 min
Pd(PPh3)4
a The reaction was conducted in anoxic conditions. Deg., Degradation. All reactions were performed at reflux.
26–29 were obtained in very good yields (89–96%).
The cleavage of the Boc group, occurred during the
purification process (Scheme 8).
N
O
O
R1
R2
R1
R2
a
Br
The benzoxy groups of compounds 27 and 28 were
deprotected with BBr3 in dichloromethane (30 min at
room temperature) and compounds 30 and 31 were ob-
tained in 62% and 55% yields, respectively. The reaction
appeared to be complete on TLC, but the purification by
trituration in methanol decreased the yields. The meth-
ylenedioxy substituent of compound 29 was stable under
these conditions. Reactions of 26–31 in boiling dimeth-
ylaminoethylamine led after 24 h to compounds 32–36
in satisfying yields (48–88%). It should be noted that
31 did not afford the corresponding dimethylaminoethyl
derivative but led only to a degradation of the mixture.
The presence of the basic sensitive hydroquinone-imine
system could explain this result. In addition, we noted
that the hydroxyl protected 5-azaindolocarbazoles 33
and 34 did not react with BBr3.
N
N
H
H
15 R1 = OBn, R2 =H
16 R1 = H, R2= OBn
17 R1, R2 = OCH2O
18 R1 = OBn, R2 =H, 87%
19 R1 = H, R2= OBn, 79%
20 R1,R2 = OCH2O, 88%
N
O
O
R1
R2
b
N
18-20
N
N
H
Boc
21 R1 = OBn, R2 =H, 76%
22 R1 = H, R2= OBn, 87%
23 R1,R2 = OCH2O, 72%
2.3. Preparation of analogues bearing unsubstituted
maleimide moieties
Scheme 6. Reagents and conditions: (a) for 20: i—LiHMDS
(2.9 equiv), THF, ꢀ15 ꢁC, 1 h 30 min; ii—11 (1.0 equiv), THF,
ꢀ15 ꢁC, 15 min then 0 ꢁC, 15 min, 88%; (b) 10 (1.5 equiv), Pd(PPh3)4
(10%), CuBrÆMe2S (1.5 equiv), THF, reflux, 30 min.
Since some kinase inhibitors within the indolocarbaz-
ole series are unsubstituted on the maleimide nitrogen,
we have synthesized the N-unsubstituted derivatives
40–47. Compounds 40–42 were similarly obtained in
satisfying yields (except for 42) from a Stille reaction
Hg lamp on a 100 mg scale in toluene (500 mL) in the
presence of diiodine and the expected indolocarbazoles
N
N
O
O
O
O
H
H
TFA
N
b
N
3
DDQ
N
N
N
N
H
H
H
R
25
14 R = Boc
24 R = H
a
Scheme 7. Reagents and conditions: (a) formic acid, rt 12 h, 99%; (b) H2, Pd(C) 10%, DMF, 5 days, 98%.

5308
M. Lefoix et al. / Bioorg. Med. Chem. 16 (2008) 5303–5321
N
N
O
O
N
N
O
O
O
O
7
5
H2N
R1
R2
R1
9
8
4
N
R1
a
N
N
N
2
c
R2
10
R2
N
N
N
H
N
N
N
H
11
1
H
Boc
H
H
14 R1=R2= H
26 R1=R2= H
96%
32 R1=R2= H
70%
21 R1 = OBn R2 = H
22 R1= H R2 =OBn
23 R1,R2 OCH2O
27 R1 = OBn, R2 = H 91%
28 R1= H, R2 = OBn 89%
29 R1,R2 = OCH2O 92%
33 R1 = OBn, R2 = H 88%
34 R1= H, R2 = OBn 60%
35 R1,R2 = OCH2O 62%
b
1
2
30
31
R = OH, R = H 62%
b
36 R1= OH, R2 = H 48%
R1= H, R2 = OH 55%
Scheme 8. Oxidative photocyclization and maleimide substitution. Reagents and conditions: (a) hm, 500 W DEMA-lamp, I2 (10 equiv), toluene,
30 min; (b) BBr3 (10 equiv), CH2Cl2, 0 ꢁC to rt, 30 min; (c) refluxing amine, 24 h.
of 10 with the NH maleimide derivatives 37–39
(Scheme 9).38 In a second step, the photocyclization
afforded compounds 43–45 in good yields. Com-
pounds 46 and 47 were also obtained in good yields
via deprotection of the hydroxyl group of 44 and 45
with BBr3 in dichloromethane.
2.4. Glycosylation reactions
Introduction of a sugar moiety could improve both
the solubility and biodisponibility of indolocarbazoles
derivatives. Whatever the methods be, all our attempts
starting from indolocarbazole 26 remained unsuccess-
ful. Glycosylation of compound 5 by a Mitsunobu
reaction involving tetraacetyl-D-glucopyranoside, was
also unproductive. By replacing the tetraacetyl-D-
glucopyranoside with the corresponding tetrabenzyl-
D-glucopyranoside 50 (Scheme 10), compound 5139
was obtained as a single b anomer in very good yield
(96%). Compound 52 was isolated in a moderate yield
It should be noted that compound 44 reacted with an
excess of iodomethane 48 in a sealed tube to give com-
pound 49 (37%) that is N-alkylated on the pyridine
moiety. The maleimide function was not alkylated in
the absence of base, and the starting material was
recovered.
H
N
H
N
O
O
O
O
R1
R2
R1
R2
N
a
Br
N
N
Boc
N
H
H
37 R1= R2 = H
40 R1 = R2= H
74%
38 R1 = OBn, R2 = H
39 R1 = H, R2 = OBn
41 R1 = OBn R2 = H 80%
42 R1 = H R2 = OBn 28%
b
H
N
O
O
-
H
N
I
N+
Bn
O
O
O
R1
R2
N
N
N
H
H
N
49 (37%)
N
H
H
d
43 R1 = R2 = H
(85%)
44 R1 = OBn, R2 =H (70%)
45 R1 = H, R2 = OBn (86%)
46 R1= OH, R2 = H (71%)
47 R1 = H, R2 = OH (88%)
c
Scheme 9. Reagents and conditions: (a) 10 (1.5 equiv) Pd(PPh3)4 (10%), CuBrÆMe2S (1.5 equiv), THF, reflux, 30 min; (b) hm, 500 W DEMA-lamp, I2
(10 equiv), toluene, 30 min; (c) BBr3 (10 equiv), CH2Cl2, 0 ꢁC to rt, 30 min; (d) 48 (3.5 equiv), DMF, 60 ꢁC, 24 h, sealed tube.

M. Lefoix et al. / Bioorg. Med. Chem. 16 (2008) 5303–5321
5309
N
O
O
OBn
O
N
O
O
50
BnO
BnO
Br
OH
OBn
Br
N
a
N
H
OBn
O
5
BnO
51 96%
OBn
OBn
b
N
O
O
N
O
O
a
N
N
50
N
H
N
Boc
N
N
Boc
OBn
O
14
BnO
52 (from 51 35%,
from 14 33%)
OBn
OBn
Scheme 10. Reagents and conditions: (a) 50 (1.5 equiv), PPh3 (3.0 equiv), DIAD (3.0 equiv), THF, 0 ꢁC then rt, 1 h. (b) 10 (1.5 equiv), Pd(PPh3)4
(10%), CuBrÆMe2S (1.5 equiv), THF, reflux, 30 min.
(35%) by performing on 51 the Stille reaction previ-
ously described. This compound can also be obtained
in approximately the same overall yield (33%) via a
Mitsunobu reaction involving 14 and tetrabenzyl-D-
glucopyranoside 50.
3. Results and discussion
All the new 5-azaindolocarbazole derivatives were first
evaluated in vitro for their cytotoxicity against two tu-
mor cell lines, a murine leukemia cell line (L1210) and
a human colon carcinoma cell line (HT29). The results
(IC50) are reported in Table 4. These compounds were
then evaluated in vitro for their Chk1 inhibiting
properties.
Deprotection of the azaindole moiety of 52 was achieved
using formic acid and led to compound 53 in excellent
yield (99%, the deprotection was necessary in order to
carry out the oxidative photocyclization with good
yield).19 Compound 54 was then obtained in a 69% yield
(Scheme 11).
3.1. Cytotoxicity
As expected, significant variations of the cytotoxicity
were observed according to the nature and the position
of the substituents. The structure–activity relationships
discussed hereafter are those obtained from the cytotox-
icity data on L1210 cell line (Table 4).
Our attempts to debenzylate the sugar moiety by
hydrogenolysis were unsuccessful. Independent of the
hydrogen pressure, the temperature and the amount of
Pd/C, a mixture of partially debenzylated derivatives
was always obtained. The use of BBr3 at ꢀ78 ꢁC (reac-
tion completed in 10 min) led, in 57% yield, to the com-
pound 55 bearing an unexpected quaternary pyridine
nitrogen atom.
The unsubstituted compound 43 was relatively cytotoxic
with an IC50 of 0.6 lM against L1210 cells. Its direct
analogues substituted in position 10 (on the indole part
of the structures) with an hydroxy or a benzyloxy (com-
pounds 47 and 45) retained some cytotoxicity with IC50
(L1210) of, respectively, 3.3 and 1.1 lM, whilst patterns
for cytotoxicity for the compounds substituted in posi-
tion 9 were less obvious. The 9-benzyloxy substituted
compounds 44 remained rather active (IC50
(L1210) = 1.5 lM) whilst the 9-hydroxy substituted
compound 46 was inactive (IC50 (L1210) = 80.7 lM).
The peracetylation of 55 using acetic anhydride in
pyridine at room temperature, afforded the expected
compound 56 in a 24% yield, but also the triacetylated
compound 57, which was isolated by flash chromatog-
raphy in a 19% yield (Scheme 11). The obtention of
57 confirmed the lack of reactivity of the 20-hydroxy
group on the sugar, which was, as described for the
rebeccamycin derivatives, engaged in a intramolecular
hydrogen bond with the NH of the ‘indole’
moiety.40,41
Contrary to 30, which was clearly 7-fold more cytotoxic
than its nonmethylated direct analogue 46, compounds

5310
M. Lefoix et al. / Bioorg. Med. Chem. 16 (2008) 5303–5321
induced a clear improvement of the cytotoxicity com-
N
N
O
O
O
R
pared to their N-methyl substituted counterparts 29
and 30 (IC50 (L1210) of, respectively, 0.495 and
11.9 lM).
O
O
N
b
N
N
N
This was less obvious for compound 34 (IC50
(L1210) = 1.4 lM, 10-benzyloxy substituent), which
was slightly less active than its direct counterpart (com-
pound 28, IC50 (L1210) = 0.6 lM) in the ‘N-methyl
maleimide’ series. Surprisingly, compound 34 (10-ben-
zyloxy; IC50 (L1210) = 1.4 lM) was clearly more cyto-
toxic than compound 33 (9-benzyloxy; IC50
(L1210) = 16.3 lM), whereas their analogues 44 and
45, devoid of a substitution on the maleimide moiety
were equiactive (1.5 and 1.1 lM).
N
N
H
OBn
OBn
O
BnO
BnO
54 69%
OBn
OBn
52 R = Boc
OBn
OBn
a
53 R = H 99%
N
O
O
+
Bn
Br-
N
c
54
Whatever the substituent (methyl or N,N-dimethylami-
noethyl) on the maleimide be, the introduction of the
9,10-methylenedioxy group clearly improved the cyto-
toxicity. Compounds 35 and 29 were the most active
of their subset with IC50 (L1210) of 0.195 and
0.495 lM, respectively.
N
N
H
OH
O
HO
55
57%
OH
OH
d
The glycosylated compounds 54, 55, and 56 were less
active than anticipated based upon previous results. A
possible explanation could be the protective groups
(O-benzyl or O-acetyl) on the sugar moiety and/or the
ammonium benzyl salt.
N
N
O
O
O
O
O
-
-
Br
Br
Bn
+
Bn
+
N
N
+
N
N
Without exception, all the compounds described were
significantly less cytotoxic on the HT29 than on the
L1210 cell lines with in some case (compounds 45 or
47) a good selectivity. As seen with tests on L1210 com-
pound 35 was the most potent with an IC50 (HT29) of
1.76 lM.
N
N
H
H
O
OAc
O
H
AcO
AcO
57 (19%)
56 (24%)
OAc
OAc
OAc
OAc
Scheme 11. Reagents and conditions: (a) HCOOH, rt, 12 h; (b) hm,
500 W DEMA-lamp, I2 (10 equiv), toluene, 30 min; (c) BBr3
(5.0 equiv), CH2Cl2, ꢀ78 ꢁC, 10 min; (d) Ac2O, pyridine, rt, 24 h.
DNA flow cytometric analyses were next performed on
compounds 31, 35, 43, 45 using propidium iodide stain-
ing. Compound 31 was toxic at 20 lM whereas 43 was
the sole derivative inducing an accumulation of cells in
G1 phase (60% at 1 lM). Compounds 35 and 45 showed
a G2 + M phase accumulation of cells (35, 62% at 1 lM;
45, 43% at 5 lM). The most cytotoxic compound 35 was
also the most active on the cell cycle. Nevertheless, there
was not direct relationship between the high value of
Chk1 inhibition for 45 and the antiproliferative activity.
28 and 31 bearing a methyl on the nitrogen of the malei-
mide were in the same range of potency as their direct
unsubstituted counterparts 45 and 47. Compound 29
bearing a 9,10-methylenedioxy group was the most po-
tent of this subset of derivatives with an IC50 (L1210)
of 0.495 lM. On this particular point (N-methylation
of the maleimide), the structure–activity relationships
in the 5-azaindolocarbazole series were different from
those obtained with the previous studies on naph-
tho-20,21 and phenyl- carbazoles16 where N-methylation
of the maleimide moiety led to micromolar cytotoxic
derivatives. From these results, it can be noticed that
the increase of the basicity due to the 5-azaindole ring
improved the cytotoxicity of aglycones.
3.2. Chk1 inhibition
The role of Chk1 in regulating the S phase: G2 phase
has been demonstrated, and validates this kinase as a
target for anticancer drug candidates.25,27 Some com-
pounds such as staurosporine and UCN-01 are de-
scribed as potent but nonselective Chk1 inhibitors
(Fig. 1). Another compound, isogranulatimide, is a po-
tent Chk1 inhibitor (IC50 0.438 lM) with moderate
cytotoxicity (10 lM on L1210).29
Substitution of the maleimide with a N,N-dimethylami-
noethyl chain resulted in more soluble derivatives that,
with the exception of compound 33 (IC50
(L1210) = 16.3 lM; 9-benzyloxy substituent), retained
good cytotoxicity. For compounds 35 (IC50
(L1210) = 0.195 lM) and 36 (IC50 (L1210) = 2.6 lM)
bearing, respectively, a 9,10-methylenedioxy and a 9-hy-
droxy group, the N,N-dimethylaminoethyl substitution
Our compounds bearing a substitution on the maleimide
moiety were without significant Chk1 inhibition. The
unsubstituted compound 43 was found slightly active.
Whilst substitution with a 9-benzyloxy group resulted
in a moderate improvement of the activity (compound

M. Lefoix et al. / Bioorg. Med. Chem. 16 (2008) 5303–5321
5311
Table 4. In vitro antiproliferative activities toward murine leukemia L1210 and human colon HT29a
Entry Structures
Substitutions
Compound L1210
HT29
% of Chk1 Chk1
(IC50 lM) (IC50 lM) inhibition
at 10 lM
inhibition
(IC50 lM)
CH3
N
O
O
1
2
R1 = H, R2 = OBn
28
0.6
0.495
2.0
3.345
27.0
26.7
38.5
66.6
ND
ND
ND
5
R1, R2 = AOCH2OA 29
30
31
R1
R2
3
4
R1 = OH, R2 = H
R1 = H, R2 = OH
11.9
2.7
>100
16.2
N
N
N
H
H
N
5
6
7
8
9
R1 = R2 = H
32
33
34
0.47
3.8
19.5
2.9
49.4
17.6
32.7
6.7
ND
ND
ND
ND
ND
N
O
O
R1 = OBn, R2 = H
R1 = H, R2 = OBn
16.3
1.4
R1
R2
R1, R2 = AOCH2OA 35
0.195
2.6
1.76
N
R1 = OH, R2 = H
36
50.9
48.9
N
N
H
H
H
N
O
O
10
11
12
13
14
R1 = H, R2 = H
43
44
45
46
47
0.6
1.5
1.1
1.5
7.6
98.6
90.6
95.9
99.1
98.7
5
R1 = OBn, R2 = H
R1 = H, R2 = OBn
R1 = OH, R2 = H
R1 = H, R2 = OH
1.32
0.025
0.027
0.014
R1
32.4
N
80.7
3.3
>100
>100
R2
N
N
H
H
CH3
N
O
O
N
15
—
54
>100
ND
49
ND
N
N
H
OBn
O
BnO
O
OBn
OBn
CH3
N
O
-
Br
Bn
+
16
17
R = OH
R = OAc
55
56
12.8
14.3
63.7
>100
51.4
46.5
ND
ND
N
N
N
H
OR
O
RO
OR
OR
a IC50 values are presented as means of duplicate experiments.

5312
M. Lefoix et al. / Bioorg. Med. Chem. 16 (2008) 5303–5321
44, IC50 (Chk1) = 1.02 lM), substitution with 10-ben-
zyloxy, 9-or 10-hydroxy led to the very potent com-
pounds 45, 46, and 47 with IC50 (Chk1) of,
respectively, 72, 27, and 14 nM. The 15-fold lower activ-
ity of the 9-benzyloxy substituted compound 44 by com-
parison with the 10-benzyloxy compound 45 could be
explained by steric hindrance in the ATP pocket of the
kinase. Like reference compounds such as stauro-
sporine, UCN-01, and isogratulatimide, our most potent
original Chk1 inhibitors (compounds 45, 46, and 47),
which inhibited the enzyme in a nanomolar range are
not substituted on the nitrogen atom of the maleimide
moiety.
the attribution of chemical shift i refers to the indole
part and a to the 5-azaindole moiety. Abbreviation
HSQC, Heteronuclear Single Quantum Coherence.
5.1.1. 1-Methyl-3,4-bis(1H-pyrrolo[3,2-c]pyridin-1-yl)-
pyrrole-2,5-dione (6). To a solution of 5-azaindole 1
(50 mg, 0.42 mmol) in toluene (2 mL), a solution of
LiHMDS (1 M in hexanes, 0.92 mL, 0.92 mmol) was
dropwise added. After 15 min, 3,4-dibromo-N-meth-
ylmaleimide 11 (40 mg, 0.14 mmol) was added and the
mixture heated at reflux for 5 h. Hydrolysis was per-
formed with water (10 mL) and the mixture extracted
three times with EtOAc (3· 20 mL). After drying over
MgSO4 and evaporation in vacuo the residue was puri-
fied by silica gel column (AcOEt/MeOH 9:1) to afford
compound 6 as a yellow solid (15 mg, 29%). Mp: 152–
155 ꢁC (degradation); IR (KBr, cmꢀ1) m 723, 1465,
1713 (C@O), 2927 (CH arom); 1H NMR (CDCl3) d
3.28 (s, 3H, NCH3), 6.27 (d, 2H, H-6,JH6–H7 = 5.7 Hz),
6.89 (d, 2H, H-3, JH3–H2 = 3.4 Hz), 7.56 (d, 2H, H-2,
JH3–H2 = 3.4 Hz), 7.94 (d, 2H, H-7, JH6–H7 = 5.7 Hz),
8.83 (s, 2H, H-4); 13C NMR (CDCl3) d 24.8 (NCH3),
105.7 (2 CH), 107.5 (2 CH), 126.2 (2 Cq), 127.7 (2
CH), 139.8 (2 Cq), 143.2 (2 CH), 144.4 (2 CH), 150.6
(2 Cq) 165.7 (2 C@O); MS (IS) m/z 344 [M+H]+. Anal.
Calcd for C19H13N5O2: C, 66.47; H, 3.82; N, 20.40.
Found: C, 66.89; H, 3.74; N, 20.56.
4. Conclusions
A new class of 1H-pyrido[30,40:4,5]pyrrolo[2,3-a] pyrrol-
o[3,4-c]carbazole currently named 5-azaindolocarbazole
have been prepared using a Stille approach for assem-
bling the 5-azaindole unit with the indolic counterpart.
Our results highlighted the different chemical behaviors
of the 5-azaindole unit compared to indole and 7-azain-
dole. A photocyclization strategy led to the correspond-
ing carbazoles, which were easily glycosylated. Some of
these compounds bearing a 9,10-methylenedioxy group
and a substituent on the maleimide part (compounds
29 and 35) are potent cytotoxic with IC50 of, respec-
tively, 0.495 and 0.195 lM against the murine L1210 cell
line. Three other compounds 45, 46, and 47, which are
unsubstituted on the maleimide moiety, are promising
novel Chk1 inibitors with IC50 of 72, 27, and 14 nM,
respectively.
5.1.2. 3-[1-(tert-Butyloxycarbonyl)-1H-indol-3-yl]-1-
methyl-4-(1H-pyrrolo[3,2-c]pyridin-1-yl)pyrrole-2,5-dione
(8). A 1 M solution of LiHMDS in hexanes (1.5 mL,
1.5 mmol) was added to a cooled solution (ꢀ30 ꢁC) of
compound 1 (83 mg, 0.70 mmol) in THF (3 mL). After
1 h at ꢀ30 ꢁC a solution of compound 7 (237 mg,
0.59 mmol) in THF (5 mL) was added dropwise. The
mixture was stirred for 15 min at ꢀ20 ꢁC then 45 min
at ꢀ10 ꢁC. After the addition of an aqueous solution
of 0.3 M HCl, the aqueous layer was extracted with
EtOAc. The combined organic layers were washed with
water and evaporated under reduced pressure. The resi-
due was purified by silica gel column (EtOAc) to yield 8
as an orange oil (29 mg, 11%). 1H NMR (CDCl3) d 1.72
(s, 9H, C(CH3)3), 3.24 (s, 3H, NCH3), 6.05 (d, 1H,
We designed a new family of active products, which
offers numerous possibilities to design either cytotoxic
or Chk1 inhibitors. The 5-azaindolocarbazoles deriva-
tives appear very promising, and are currently under
further investigations to improve their Chk1 inhibiting
properties. Their selectivity over other kinases including
CDKs would be evaluated in a near future.
5. Experimental
JH4i–H5i = 8.0 Hz, H-4i,), 6.68 (dd, 1H, JH5i–H6i
7.3 Hz, JH4i–H5i = 8.0 Hz, H-5i), 6.85 (d, 1H, JH3a–H2a
=
=
5.1. General methods
3.4 Hz, H-3a), 6.90 (d, 1H, JH6a–H7a = 6.0 Hz, H-6a),
7.13 (dd, 1H, JH6i–H7i = 8.1 Hz, JH5i–H6i = 7.3 Hz,
H-6i), 7.48 (d, 1H, JH3a–H2a = 3.4 Hz, H-2a), 8.07 (m,
2H, H-7i, H-7a), 8.36 (s, 1H, H-2i), 8.87 (s, 1H, H-4a);
13C NMR (CDCl3)d 24.6 (NCH3), 28.2 (C(CH3)3),
85.4 (CMe3), 106.1 (CH-3a), 107.3 (CH-6a), 108.3
(Cq), 115.4 (CH-7i), 119.6 (CH-4i), 123.0 (Cq), 123.6
(CH-5i), 125.4 (CH-6i), 127.3 (Cq), 128.8 (CH-2a),
129.4 (Cq), 130.4 (CH-2i), 135.0 (Cq), 140.1 (Cq),
142.1 (CH-7a), 143.8 (CH-4a), 149.0 (COOtBu), 167.4
(C@O), 169.2 (C@O); MS (IS) m/z: 443.5 [M+H]+,
387.0 [M+HtBu]+, 343.0 [M+H-Boc]+. Anal. Calcd for
C25H22N4O4: C, 67.86; H, 5.01; N, 12.66. Found: C,
68.24; H, 5.15; N, 12.41.
1H and 13C NMR spectra were recorded on a Bruker
Avance 250 or 500 instruments using CDCl3 or
DMSO-d6. 13C NMR was performed at 62.9 or
125.75 Hz. The chemical shifts are reported in ppm (d
scale) and all J values are in Hz. The following abbrevi-
ations are used: singlet (s), doublet (d), doubled doublet
(dd), triplet (t), multiplet (m), quaternary carbon (Cq).
Melting points are uncorrected. IR absorptions were re-
corded on a Perkin-Elmer PARAGON 1000 PC and
values were reported in cmꢀ1. MS spectra (Ion Spray)
were performed on a Perkin-Elmer Sciex API 300 or a
Bruker MALDI-TOF Omniflex. Monitoring of the reac-
tions was performed using silica gel TLC plates (silica
Merck 60 F254). Spots were visualized by UV light at
254 and 356 nm. Column chromatography was per-
formed using silica gel 60 (0.063–0.200 mm, Merck). In
5.1.3. 3-[1-(tert-Butyloxycarbonyl)-1H-indol-3-yl]-1-
methyl-4-(1H-pyrrolo[3,2-c]pyridin-3-yl)pyrrole-2,5-dione
(9). A 1 M solution of LiHMDS in hexanes (1.8 mL,

M. Lefoix et al. / Bioorg. Med. Chem. 16 (2008) 5303–5321
5313
1.77 mmol) was added to a cooled solution (ꢀ30 ꢁC)
of compound (200 mg, 1.69 mmol) in toluene
N4O4: C, 67.86; H, 5.01; N, 12.66. Found: C, 68.07; H,
5.17; N, 12.50.
1
(5 mL). After 1 h at ꢀ30 ꢁC a solution of compound
7 (170 mg, 0.42 mmol) in toluene (5 mL) was added
dropwise. The mixture was stirred for 15 min at
ꢀ20 ꢁC then 45 min at ꢀ10 ꢁC. After addition of an
aqueous solution of 0.3 M HCl (pH 7), the aqueous
layer was extracted with EtOAc (3· 25 mL). The com-
bined organic layers were washed with water and
evaporated under reduced pressure. The residue was
purified on a silica gel column (petroleum ether/
EtOAc 6:4) to yield a solid (44 mg, 24%). Mp: 175–
177 ꢁC; IR (KBr, cmꢀ1) m 1703 (C@O), 1740 (C@O),
5.1.5. 3-Bromo-4-(5H-[1,3]dioxolo[4,5-f]indol-7-yl)-1-
methylpyrrole-2,5-dione (20). A solution of 17 (1.92 g,
11.90 mmol) in THF (50 mL) was cooled to ꢀ15 ꢁC
and a solution of LiHMDS (1 M in hexanes, 35.7 mL,
35.7 mmol) was dropwise added in 30 min. The mixture
was stirred at ꢀ15 ꢁC for 1 h before adding in 30 min the
3,4-dibromo-N-methylmaleimide 11 (3.20 g, 11.91 mol)
dissolved in THF (20 mL). After stirring at ꢀ15 ꢁC for
15 min then at 0 ꢁC for 15 min, an aqueous 0.3 M HCl
is added till pH 3. Extraction with EtOAc (2· 50 mL)
and washing with brine (2· 20 mL) leaved to a solid res-
idue after evaporation. The residue was triturated in the
minimum of methanol to yield after filtration 20 as a
pale brown solid (3.6 g, 88%). Mp: 150–152 ꢁC; IR
(KBr, cmꢀ1)m 1452, 1708 (C@O), 3376 (NH); 1H
NMR (CDCl3)d 3.16 (s, 3H, NCH3), 5.99 (s, 2H,
OCH2O), 6.87 (s, 1H, H-7), 7.43 (s, 1H, H-4), 7.85 (d,
1H, JH2–NH = 3.0, H-2), 8.63 (br s, 1H, NH); 13C
NMR (DMSO-d6)d 4.5 (NCH3), 92.8 (CH-7), 100.7
(OCH2O), 100.9 (CH-4), 104.3 (Cq), 113.0 (Cq), 120.7
(Cq), 129.4 (CH-2), 131.5 (Cq), 137.6 (Cq), 143.1 (Cq),
144.7 (Cq), 166.5 (C@O), 169.1 (C@O). Anal. Calcd
for C14H9BrN2O4: C, 48.16; H, 2.60; N, 8.02. Found:
C, 48.55; H, 2.43; N, 7.86.
3388 (NH); 1H NMR (CDCl3)
d
1.68 (s, 9H,
C(CH3)3), 3.22 (s, 3H, NCH3), 6.03 (d, 1H, JH4i–H5i
=
8.1 Hz, H-4i), 6.60 (dd, 1H, JH5i–H6i = 7.2 Hz,
JH4i–H5i = 8.1 Hz, H-5i), 7.01 (dd, 1H, JH6i–H7i = 7.8 Hz,
JH5i–H6i = 7.2 Hz, H-6i), 7.10–7.17 (m, 1H, H-6a), 7.27
(d, 1H, JH6i–H7i = 7.8 Hz, H-7i), 7.50 (d, 1H, JH2a–NH
=
3.4 Hz, H-2a), 7.89 (s, 1H, H-2i), 8.11–8.16 (m, 2H, H-
4a, H-7a), 9.82 (br s, 1H, NH); 13C NMR (CDCl3) d
24.5 (NCH3), 28.3 (C(CH3)3), 84.8 (CMe3), 104.9 (Cq),
110.3 (Cq), 111.9 (CH), 115.6 (Cq), 120.0 (CH), 121.2
(CH), 121.7 (CH), 122.7 (CH), 123.5 (CH), 124.9 (CH),
125.2 (CH), 126.4 (CH), 126.7 (Cq), 127.6 (Cq), 128.9
(Cq), 130.9 (Cq), 136.2 (Cq), 149.4 (COOtBu), 171.5
(C@O), 171.7 (C@O); MS (IS) m/z: 443.5 [M+H]+,
387.0 [M+HtBu]+, 343.0 [M+H-Boc]+. Anal. Calcd for
C25H22N4O4: C, 67.86; H, 5.01; N, 12.66. Found: C,
67.51; H, 4.88; N, 12.83.
5.1.6. 3-(5-Benzyloxy-1H-indol-3-yl)-4-[1-(tert-butyl oxy-
carbonyl)-1 H-pyrrolo[3,2-c]pyridin-3-yl]-1-methyl pyr-
role-2,5-dione (21). Similar preparation as for 14
starting from 18.32 After a flash chromatography
(EtOAc/MeOH 95:5), compound 21 was obtained as
an orange solid (504 mg, 76%). Mp: 145–146 ꢁC; IR
(KBr, cmꢀ1) m 1152 (C–O–C), 1712 (C@O), 1756
5.1.4. 4-[1-(tert-Butyloxycarbonyl)-1H-pyrrolo[3,2-c]-
pyridin-3-yl]-1-methyl-3-(1H-indol-3-yl)pyrrole-2,5-dione
(14). To
a
solution of compound 1036 (3.63 g,
9.53 mmol) in THF (30 mL), compound 5 (2.20 g,
6.35 mmol), CuBr.Me2S (1.96 g, 9.53 mmol) and
Pd[P(C6H5)3]4 (0.370 g, 0.32 mmol) were added. The
mixture was heated to reflux for 30 min, then a 33%
aqueous NH4OH was added (2 mL/mmol). The catalyst
was filtered over Celite and washed with EtOAc (2·
30 mL). The organic layer was then washed with a
20% aqueous solution of sodium carbonate until the dis-
appearance of the blue color then with brine, and finally
evaporated in vacuo. The crude residue was purified by
chromatography over silica gel (petroleum ether/EtOAc
7:3) to afford 14 as an orange solid (2.6 g, 92%). Mp:
174–176 ꢁC (degradation); IR (KBr, cmꢀ1)m 1703
1
(C@O), 3430 (NH); H NMR (CDCl3) d 1.64 (s, 9H,
C(CH3)3), 3.22 (s, 3H, NCH3), 4.26 (s, 2H, CH2Ph),
6.25 (d, 1H, JH4i–H6i = 2.2 Hz, H-4i), 6.64 (dd, 1H,
JH6i–H7i = 8.7, JH4i–H6i = 2.2 Hz, H-6i), 6.91 (d, 1H,
JH6i–H7i = 8.7 Hz, H-7i), 7.19-7.34 (m, 5H, CH2Ph),
7.94 (d, 1H, JH2i–NH = 2.6 Hz, H-2i), 8.06 (d, 1H,
JH6a–H7a = 5.2 Hz, H-6a), 8.12 (s, 1H, H-2a), 8.23 (s,
1H, H-4a), 8.34 (d, 1H, JH6a–H7a = 5.2 Hz, H-7a),
10.87 (br s, 1H, NH); 13C NMR (CDCl3)d 24.5
(NCH3), 28.1 (C(CH3)3), 70.3 (CH2Ph), 86.0 (CMe3),
103.9 (CH-4i), 106.0 (Cq), 110.3 (CH-6a), 110.9 (Cq),
113.2 (CH-7i), 113.9 (CH-6i), 121.2 (Cq), 126.0 (Cq),
126.1 (Cq), 127.5 (2 CH), 128.0 (CH), 128.5 (CH-4a),
128.6 (2 CH), 130.8 (CH-2i), 131.7 (Cq), 133.1 (Cq),
137.1 (Cq), 139.5 (Cq), 143.4 (CH-7a), 143.8 (CH-2a),
148.7 (Cq), 153.7 (COOtBu), 171.8 (C@O), 171.9
(C@O); MS (IS) m/z: 549.5 [M+H]+, 493.5 [M+H-tert-
butyl]+, 449.0 [M+H-Boc]+. Anal. Calcd for
C32H28N4O5: C, 70.06; H, 5.14; N, 10.21. Found: C,
69.70; H, 5.01; N, 10.37.
1
(C@O), 3380 (NH); H NMR (CDCl3) d 1.75 (s, 9H,
C(CH3)3), 3.22 (s, 3H, NCH3), 6.64 (ddd, 1H,
JH5i–H4i = 7.8 Hz, JH5i–H6i = 7.8 Hz, JH5i–H7i = 1.6 Hz,
H-5i), 6.74 (d, 1H, JH5i–H4i = 7.8 Hz), H-4i, 6.90-7.00
(m, 2H, H-7i and H-6i), 7.88 (d, 1H, JH2i–NH = 2.8 Hz,
H-2i), 8.00 (s, 1H, H-2a), 8.03 (d, 1H, JH6a–H7a
=
5.7 Hz, H-6a), 8.28 (d, 1H,JH6a–H7a = 5.7 Hz, H-7a),
8.30 (s, 1H, H-4a), 11.40 (br s, 1H, NH); 13C NMR
(CDCl3)d 24.5 (NCH3), 28.2 (C(CH3)3), 85.9 (CMe3),
106.1 (Cq), 110.2 (Cq), 110.4 (CH-6a); 112.3 (CH-6i),
120.5 (CH-5i), 120.6 (Cq), 122.4 (Cq), 122.7 (CH-7i),
125.3 (Cq), 125.7 (CH-4i), 128.8 (CH-4a), 130.0 (CH-
2i), 132.5 (Cq); 136.5 (Cq), 139.5 (Cq), 143.3 (CH-7a),
143.9 (CH-2a), 148.8 (COOtBu), 171.8 (C@O), 171.9
(COOtBu); MS (IS) m/z: 443.0 [M+H]+, 387.0 [M+H-
tert-butyl]+, 343.0 [M+H-Boc]+. Anal. Calcd for C25H22
5.1.7. 3-(6-Benzyloxy-1H-indol-3-yl)-4-[1-(tert-butyloxy
carbonyl)-1H-pyrrolo[3,2-c]pyridin-3-yl]-1-methyl pyr-
role-2,5-dione (22). Similar preparation as for 21 starting
from 19.32 After a flash chromatography (EtOAc), com-
pound 22 was obtained as an orange solid (1.1 g, 87%).
Mp: 153–155 ꢁC (degradation); IR (KBr, cmꢀ1) m 1153
(C–O–C), 1692 (C@O), 1754 (C@O), 3444 (NH); 1H

5314
M. Lefoix et al. / Bioorg. Med. Chem. 16 (2008) 5303–5321
NMR (CDCl3)d 1.75 (s, 9H, C(CH3)3), 3.18 (s, 3H,
NCH3), 4.79 (s, 2H, CH2Ph), 6.36 (d, 1H, JH4i–H5i
5.1.10. 3-(1H-Indol-3-yl)-1-methyl-4-(1H-pyrrolo[3,2-c]
pyridin-3-yl)pyrrolidine-2,5-dione (25). A suspension of
compound 24 (95 mg, 0.028 mmol) and palladium over
carbon 10% (10 mg, 0.009 mmol) in DMF (10 mL) was
stirred under hydrogen pressure (50 psi) for 5 days at
30 ꢁC, in a Parr apparatus. The catalyst was filtered
and washed with methanol, the filtrate was evaporated
in vacuum and the residue was purified by silica gel col-
umn (petroleum ether/EtOAc 9:1) to yield compound 25
as a red solid (94 mg, 98%). Mp: 182–184 ꢁC; IR (KBr,
=
8.8 Hz, H-4i), 6.58 (d, 2H, H-5i, H-7i), 7.26 (m, 5H,
H arom), 7.73 (s, 1H, H-2i), 8.02–8.04 (m, 2H, H-2a,
H-6a), 8.28 (s, 2H, H-4a, H-7a), 11.57 (br s, 1H,
NH); 13C NMR (CDCl3)
d 24.5 (NCH3), 28.3
(C(CH3)3), 70.3 (CH2Ph), 85.9 (CMe3), 96.6 (CH-7i),
106.1 (Cq), 110.3 (CH-6a), 111.2 (CH-4i), 120.1 (CH-
5i), 121.3 (Cq), 122.1 (Cq), 124.3 (Cq), 125.3 (Cq),
127.6 (2 CH), 127.9 (CH), 128.5 (2 CH), 128.8 (CH-
4a), 129.3 (CH-2i), 132.5 (Cq), 137.2 (Cq), 137.4
(Cq), 139.5 (Cq), 143.4 (CH-7a), 144.0 (CH-2a), 148.8
(Cq), 155.7 (COOtBu), 171.7 (C@O), 171.9 (C@O);
MS (IS) m/z: 549.5 [M+H]+. Anal. Calcd for
C32H28N4O5: C, 70.06; H, 5.14; N, 10.21. Found: C,
70.37; H, 5.33; N, 10.08.
1
cmꢀ1) m 1699 (C@O), 3397 (NH); H NMR (MeOD) d
3.14 (s, 3H, NCH3), 4.45 (d, 1H, JCH–CH = 6.7 Hz), 4.60
(d, 1H, JCH–CH = 6.7 Hz), 6.92 (ddd, 1H, JH5i–H6i
=
7.1 Hz, JH5i–H4i = 7.9 Hz, JH5i–H7i = 1.0 Hz, H-5i),
7.05 (ddd, 1H, JH6i–H7i = 8.1 Hz, JH6i–H4i = 1.0 Hz,
JH5i–H6i = 7.1 Hz, H-6i), 7.15 (s, 1H, H-2i), 7.23–7.35 (m,
4H, H-7i, H-4i, H-2a, H-6a), 8.05 (br s, 1H, H-7a), 8.39
(s, 1H, H-4a); 13C NMR (MeOD) d 25.6 (NCH3), 47.7
(CH), 48.4 (CH), 110.8 (CH-6a), 112.8 (CH-7i), 119.3
(CH-5i), 120.3 (CH-6i), 120.8 (Cq), 122.1 (Cq), 122.9
(CH-2i), 123.2 (Cq), 125.1 (CH-4i), 126.5 (CH-2a), 130.6
(Cq), 131.4 (Cq), 138.4 (Cq), 140.2 (CH-7a), 142.2 (CH-
4a), 178.7 (C@O), 179.3 (C@O); MS (IS) m/z: 345.0
[M+H]+. Anal. Calcd for C20H16N4O2: C, 69.76; H,
4.68; N, 16.27. Found: C, 70.13; H, 4.52; N, 16.12.
5.1.8. 3-(5H-[1,3]Dioxolo[4,5-f]indol-7-yl)-4-[1-(tert-
butyloxycarbonyl)-1H-pyrrolo[3,2-c]pyridin-3-yl]-1-meth-
ylpyrrole-2,5-dione (23). Similar preparation as for 21
starting from 20. After a flash chromatography (petro-
leum ether/EtOAc 2/8), compound 23 was obtained as
a red solid (841 mg, 72%). Mp: 179–181 ꢁC; IR (KBr,
cmꢀ1) m 1151, 1701 (C@O), 1754 (C@O), 3200-3600
1
(NH); H NMR (CDCl3) d 1.75 (s, 9H, C(CH3)3), 3.19
(s, 3H, NCH3), 5.71 (s, 2H, OCH2O), 6.15 (s, 1H, H-
4i), 6.36 (s, 1H, H-7i), 7.70 (s, 1H, H-2i), 8.01 (s, 1H,
H-2a), 8.06 (d, 1H, H-6a, JH6a–H7a = 5.6 Hz), 8.30–8.32
(m, 2H, H-7a and H-4a), 11.93 (s, 1H, NH); 13C
NMR (CDCl3) d 24.4 (NCH3), 28.2 (C(CH3)3), 85.9
(CMe3), 92.9 (CH-7i), 99.0 (CH-4i), 100.5 (OCH2O),
106.2 (Cq), 110.1 (Cq), 110.3 (CH-6a), 119.9 (Cq),
121.9 (Cq), 125.3 (Cq), 128.7 (CH-7a), 132.2 (CH-2i),
139.7 (Cq), 143.1 (CH-4a), 143.2 (Cq), 143.8 (CH-2a),
144.9 (Cq), 148.7 (COOtBu), 171.7 (C@O), 171.8
(C@O); MS (IS) m/z: 487 [M+H]+. Anal. Calcd for
C26H22N4O6: C, 64.19; H, 4.56; N, 11.52. Found: C,
64.56; H, 4.74; N, 11.36.
5.1.11. 6-Methyl-1H-pyrido[3040:4,5]pyrrolo[2,3-a]pyrrol-
o[3,4-c] carbazole-5,7(6H,12H)-dione (26). A solution of
14 (100 mg, 0.226 mmol) and diiodine (575 mg,
2.26 mmol) in toluene (450 mL) was irradiated for
30 min in a quartz vessel with a ‘DEMA UV-lamp
TQ-718 500 W’. The mixture was then treated with a
solution of 10% aqueous sodium metabisulfite
(100 mL). The aqueous layer was extracted with EtOAc
(2· 25 mL) and the combined organic layers were
washed twice with water (25 mL). After evaporation,
the residue was washed first with methanol (20 mL) then
with hot DMF (2· 20 mL). The DMF extract was con-
centrated till 2 mL. After cooling and addition of EtOAc
(2 mL) the obtained precipitate was filtered and washed
successively with 10 mL of water, methanol, and diethyl
ether to give 26 as a yellow solid (74 mg, 96%). Mp:
>250 ꢁC; IR (KBr, cmꢀ1) m 973, 1146, 1264, 1705
(C@O), 3158–3585 (NH); 1H NMR (DMSO-d6,
5.1.9. 3-(1H-Indol-3-yl)-1-methyl-4-(1H-pyrrolo[3,2-c]-
pyridin-3-yl) pyrrole-2,5-dione (24). A solution of com-
pound 14 (100 mg, 0.23 mmol) in formic acid was stirred
overnight at room temperature. Evaporation of the mix-
ture under vacuum left a residue, which is dissolved in
EtOAc (10 mL) and washed with a saturated solution of
NaHCO3 till pH 7 then with brine (10 mL). After evapo-
ration compound 24 was obtained as a red solid (76 mg,
99%). Mp: 190–192 ꢁC; IR (KBr, cmꢀ1) m 1695 (C@O),
3380 (NH); 1H NMR (DMSO-d6) d 3.06 (s, 3H, NCH3),
6.60 (d, 1H, JH4i–H5i = 7.8 Hz, H-4i), 6.68 (dd, 1H, JH5i–
H6i = 7.6 Hz, JH4i–H5i = 7.8 Hz, H-5i), 6.98 (dd, 1H,
JH6i–H7i = 8.1 Hz, JH5i–H6i = 7.6 Hz, H-6i), 7.35 (d, 1H,
JH6a–H7a = 5.4 Hz, H-6a), 7.39 (d, 1H, JH6a–
H7a = 5.4 Hz, H-7i), 7.83-7.85 (m, 2H, H-2i, H-7a), 8.00
(br s, 2H, H-2a, H-4a), 11.79 (s, 1H, NH), 12.00 (br s,
1H, NH); 13C NMR (DMSO-d6) d 24.0 (NCH3), 105.1
(CH), 105.2 (CH), 107.1 (CH), 112.0 (Cq), 119.5 (CH),
120.7 (CH), 121.8 (CH), 122.3 (Cq), 125.0 (Cq), 125.6
(Cq), 128.5 (CH), 129.9 (Cq), 136.1 (Cq), 139.4 (CH),
140.4 (Cq), 143.5 (CH), 171.5 (C@O), 171.6 (C@O); MS
500 MHz) d 3.15 (s, 3H, NCH3), 7.34 (dd, 1H,JH8–H9
=
7.8 Hz, JH9–H10 = 7.7 Hz, H-9), 7.53 (dd, 1H,
JH10–H11 = 7.5 Hz, JH9–H10 = 7.7 Hz, H-10), 7.72 (d, 1H,
JH8–H9 = 7.8 Hz, H-8), 7.95 (br s, 1H, H-2), 8.62 (br s,
1H, H-1), 8.88 (d, 1H, JH10–H11 = 7.5 Hz, H-11), 9.89
(br s, 1H, H-4), 9.95 (br s, 1H, NH), 11.83 (s, 1H, NH);
13C NMR HSQC (DMSO-d6) d 23.5 (NCH3), 108.2
(C-10), 111.6 (C-2), 111.9 (C-4), 120.4 (C-3), 122.9
(C-11), 123.8 (C-1), 140.4 (C-8) ; MS (MALDI) m/z: 341
[M+H]+. Anal. Calcd for C20H12N4O2: C, 70.58; H,
3.55; N, 16.46. Found: C, 70.94; H, 3.37; N, 16.28.
5.1.12. 9-Benzyloxy-6-methyl-1H-pyrido[3040:4,5]pyrrolo-
[2,3-a]pyrrolo[3,4-c]carbazole-5,7(6H,12H)-dione
(27).
Similar preparation as for 26 starting from 21. Com-
pound 27 was obtained as a yellow solid (74 mg, 91%).
Mp: >250 ꢁC; IR (KBr, cmꢀ1) m 1124, 1706 (C@O),
(MALDI) m/z
:
343 [M+H]+. Anal. Calcd for
1
C20H14N4O2: C, 70.17; H, 4.12; N, 16.36. Found: C,
70.41; H, 4.23; N, 16.19.
3466 (NH); H NMR (DMSO-d6, 500 MHz) d 3.20 (s,
3H, NCH3), 5.25 (s, 2H, CH2Ph), 7.29–7.31 (dd, 1H,

M. Lefoix et al. / Bioorg. Med. Chem. 16 (2008) 5303–5321
5315
JH11–H10 = 8.8 Hz, JH10–H8 = 2.4 Hz, H-10), 7.35–7.37
(m, 1H, H arom), 7.42–7.45 (m, 2H, H arom),
7.57–7.59 (m, 3H, 2H arom, H-8), 7.75 (d, 1H,
JH10–H11 = 8.8 Hz, H-11), 7.79 (d, 1H, JH1–H2 = 5.5 Hz,
H-2), 8.56 (d, 1H, JH1–H2 = 5.5 Hz, H-1), 8.66 (d, 1H,
JH4–H2 = 2.2 Hz, H-4), 10.03 (s, 1H, NH), 11.71 (s,
1H, NH). 13C NMR HSQC (DMSO-d6, 500 MHz) d
23.2 (NCH3), 69.4 (CH2Ph), 107.1 (CH-11), 107.3
(CH-8), 107.3 (CH-10), 112.3 (CH-4), 112.6 (CH-1),
117.0 (CH-2), 127.5 (2 CH), 127.5 (CH), 128.0 (2 CH);
MS (MALDI) m/z: 447 [M+H]+. Anal. Calcd for
C27H18N4O3: C, 72.64; H, 4.06; N, 12.55. Found: C,
72.97; H, 3.87; N, 12.41.
11), 8.19 (d, 1H, JH8–H10 = 2.3 Hz, H-8), 8.24 (d, 1H,
JH1–H2 = 6.6 Hz, H-2), 8.77 (d, 1H, JH1–H2 = 6.6 Hz,
H-1), 9.34 (br s, 1H, OH), 9.81 (s, 1H, H-4), 11.67 (s,
1H, NH), 13.06 (s, 1H, NH); 13C NMR HSQC
(DMSO-d6)d 23.3 (NCH3), 108.1 (CH-4), 109.2 (CH-
10), 112.6 (CH-1), 117.5 (CH-2), 135.6 (CH-11), 137.1
(CH-8); MS (MALDI) m/z: 357 [M+H]+. Anal. Calcd
for C20H12N4O3: C, 67.41; H, 3.39; N, 15.72. Found:
C, 67.12; H, 3.54; N, 15.55.
5.1.16. 10-Hydroxy-6-methyl-1H-pyrido[3040:4,5]pyrrolo-
[2,3-a]pyrrolo[3,4-c]carbazole-5,7-(6H,12H)-dione (31).
Similar preparation as for 30 starting from 28. Com-
pound 31 was obtained as a red solid (21 mg, 55%).
Mp: >250 ꢁC; IR (KBr, cmꢀ1)m 1378, 1699 (C@O),
3210–3444 (NH, OH); 1H NMR (DMSO-d6,
500 MHz) d 3.07 (s, 3H, NCH3), 6.79 (d, 1H, JH8–
H9 = 8.5 Hz, H-9), 7.03 (s, 1H, H-11), 8.19 (d, 1H,
JH2–H1 = 6.6 Hz, H-2), 8.49 (d, 1H, JH8–H9 = 8.5 Hz,
H-8), 8.74 (d, 1H, JH1–H2 = 6.6 Hz, H-1), 9.74 (s, 1H,
H-4), 9.96 (s, 1H, OH), 11.61 (s, 1H, NH), 12.90 (br s,
1H, NH); 13C NMR HSQC (DMSO-d6) d 23.4
(NCH3), 96.8 (CH-1), 109.4 (CH-10), 110.8 (CH-3),
125.0 (CH-4), 135.8 (CH-11), 137.2 (CH-8); MS (MAL-
DI) m/z: 357 [M+H]+. Anal. Calcd for C20H12N4O3: C,
67.41; H, 3.39; N, 15.72. Found: C, 67.76; H, 3.50; N,
15.63.
5.1.13. 10-Benzyloxy-6-methyl-1H-pyrido[3040:4,5]pyrrolo-
[2,3-a]pyrrolo[3,4-c]carbazole-5,7-(6H,12H)-dione
(28).
Similar preparation as for 26 starting from 22. Com-
pound 28 was obtained as a yellow solid (72 mg, 89%).
Mp: >250 ꢁC; IR (KBr, cmꢀ1) m 746, 1120, 1379, 1701
(C@O), 3000–3450 (NH); 1H NMR (DMSO-d6,
500 MHz, 40 ꢁC) d 3.17 (s, 3H, NCH3), 5.27 (s, 2H,
CH2Ph), 7.06 (dd, 1H, JH8–H9 = 8.7 Hz, JH9–H11
2.2 Hz, H-9), 7.36–7.38 (m, 2H, CH, H-11), 7.42–7.45
(m, 2H), 7.54–7.55 (m, 2H), 7.77 (d, 1H, JH1–H2
=
=
5.6 Hz, H-2), 8.55 (d, 1H, JH1–H2 = 5.6 Hz, H-1), 8.81
(d, 1H, JH8–H9 = 8.7 Hz, H-8), 9.98 (s, 1H, H-4), 11.67
(s, 1H, NH), 12.22 (s, 1H, NH); 13C NMR HSQC
(DMSO-d6, 40 ꢁC) d 23.3 (NCH3), 69.4 (CH2Ph), 93.3
(CH-1), 107.1 (CH-10), 110.2 (CH-3), 124.8 (CH-4),
127.2 (2 CH), 127.7 (CH), 128.2 (2 CH), 144.0 (CH-11),
144.8 (CH-8); MS (MALDI) m/z: 447 [M+H]+. Anal.
Calcd for C27H18N4O3: C, 72.64; H, 4.06; N, 12.55.
Found: C, 72.33; H, 4.15; N, 12.37.
5.1.17.
6-(2-Dimethylaminoethyl)-1H-pyrido[3040:4,5]-
pyrrolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-(6H,12H)-dione
(32). A solution of compound 26 (50 mg, 0.15 mmol) in
N,N-dimethylethylenediamine (1 mL) was heated to
reflux for 24 h. After evaporation, the residue was tritu-
rated in methanol and filtered to afford a brown-orange
solid (41 mg, 70%). Mp: >200 ꢁC; IR (KBr, cmꢀ1) m 800,
1019, 1260, 1697 (C@O), 2956 (CH arom), 3250 (NH);
1H NMR (DMSO-d6, 500 MHz) d 2.26 (s, 6H,
N(CH3)2), 2.64–2.65 (m, 2H, CH2NMe2), 3.84 (t, 2H,
J = 6.5 Hz, CH2N), 7.36 (dd, 1H, JH8–H9 = 7.6 Hz,
JH9–H10 = 7.4 Hz, H-9), 7.57 (dd, 1H, JH10–
H11 = 7.9 Hz, JH9–H10 = 7.4 Hz, H-10), 7.71–7.74 (m,
2H, H-8 and H-2), 8.56 (d, 1H, JH1–H2 = 5.5 Hz, H-1),
8.98 (d, 1H, JH10–H11 = 7.9 Hz, H-11), 10.03 (s, 1H, H-
4), 12.89 (s, 1H, NH), 13.25 (br s, 1H, NH); 13C
5.1.14. 1,3-Dioxolo[4,5-b]-6-methyl-1H-pyrido[30,40:4,5]
pyrrolo[3,2-i]pyrrolo[3,4-g]carbazole-5,7-dione (29). Simi-
lar preparation as for 26 starting from 23. Compound 29
was obtained as a pale brown solid (73 mg, 92%); Mp:
>250 ꢁC. IR (KBr, cmꢀ1)m 1470, 1699 (C@O), 3430
1
(NH); H NMR (DMSO-d6, 500 MHz) d 3.05 (s, 3H,
NCH3), 6.09 (s, 2H, OCH2O), 7.13 (s, 1H, H-8), 7.58
(br s, 1H, H-2), 8.10 (s, 1H, H-11), 8.44 (br s, 1H, H-
1), 9.80 (s, 1H, H-4), 11.51 (br s, 1H, NH), 11.86 (br s,
1H, NH); 13C NMR HSQC (DMSO-d6)d 23.7
(NCH3), 92.6 (CH-4), 101.0 (OCH2O), 102.0 (CH-1),
107.0 (CH-10), 144.5 (CH-11), 145.5 (CH-8). MS
(MALDI) m/z: 385 [M+H]+. Anal. Calcd for
C21H12N4O4: C, 65.63; H, 3.15; N, 14.58. Found: C,
65.90; H, 3.22; N, 14.43.
NMR HSQC (DMSO-d6)
d 35.2 (CH2N), 45.2
(N(CH3)2), 56.7 (CH2NMe2), 107.0 (CH-10), 111.5
(CH-4), 120.3 (CH-3), 124.1 (CH-1), 127.1 (CH-2),
145.0 (CH-11), 146.1 (CH-8); MS (I) m/z: 398
[M+H]+. Anal. Calcd for C23H19N5O2: C, 69.51; H,
4.82; N, 17.62. Found: C, 69.27; H, 4.89; N, 17.78.
5.1.15. 9-Hydroxy-6-methyl-1H-pyrido[3040:4,5] pyrrol-
o[2,3-a]pyrrolo[3,4-c]carbazole-5,7-(6H,12H)-dione (30).
A 1 M solution of BBr3 in dichloromethane (3.4 mL,
3.4 mmol) was added to an ice-cooled solution of com-
pound 27 (150 mg, 0.34 mmol) in dichloromethane
(2 mL), under nitrogen. After 30 min at room tempera-
ture, methanol was added. The precipitate was filtered
and washed with methanol (2· 10 mL) to give com-
pound 30 as a yellow solid (74 mg, 62%). Mp:
>250 ꢁC; IR (KBr, cmꢀ1) m 1700 (C@O), 3224–3430
5.1.18. 9-Benzyloxy-6-(2-dimethylaminoethyl)-1H-pyr-
ido[3040:4,5]pyrrolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-(6H,
12H)-dione (33). Similar preparation as for 32 starting
from27. Compound 33 was obtained as a red solid
(62 mg, 88%). Mp: >200 ꢁC; IR (KBr, cmꢀ1) m 1385
1
(C–O–C), 1705 (C@O), 3432 (NH); H NMR (DMSO-
d6, 500 MHz) d 2.24 (s, 6H, N(CH3)2), 2.61 (t, 2H,
J = 6.5 Hz, CH2NMe2), 3.81 (t, 2H, J = 6.5 Hz,
C(O)NCH2), 5,23 (s, 2H, CH2Ph), 7.28 (dd, 1H,
JH10–H11 = 8.8 Hz, JH11–NH = 2.4 Hz, H-11), 7.35 (t,
1H, J = 7.5 Hz, H arom), 7.42 (dd, 2H,3 J = 7.5 Hz,
J = 7.2 Hz, H arom), 7.58 (d, 2H, J = 7.2 Hz, H arom),
1
(NH, OH); H NMR (DMSO-d6, 500 MHz) d 3.12 (s,
3H, NCH3), 7.07 (dd, 1H, JH10–H11 = 8.7 Hz, JH8–
H10 = 2.3 Hz, H-10), 7.57 (d, 1H, JH10–H11 = 8.7 Hz, H-

5316
M. Lefoix et al. / Bioorg. Med. Chem. 16 (2008) 5303–5321
7.65 (dd, 1H,JH8–H10 = 1.7 Hz, JH10–H11 = 8.8 Hz, H-
10), 7.69 (d, 1H, JH1–H2 = 5.0 Hz, H-2), 8.54 (d, 1H,
JH2–H1 = 5.0 Hz, H-1), 8.61 (d, 1H, JH10–H8 = 1.7 Hz,
H-8), 10.00 (s, 1H, H-4), 12.63 (s, 1H, NH), 13.11 (s,
1H, NH); 13C NMR HSQC (DMSO-d6) d 35.8
(NCH2), 40.6 (N(CH3)2), 57.6 (CH2NMe2), 70.7
(CH2Ph), 107.6 (CH-10), 108.6 (CH-4), 113.3 (CH-2)
117.8 (CH-1), 128.2 (CH), 128.5 (2 CH) 129.1 (2 CH),
145.1 (CH-8), 145.9 (CH-11); MS (MALDI) m/z: 504
[M+H]+. Anal. Calcd for C30H25N5O3: C, 71.56; H,
5.00; N, 13.91. Found: C, 71.30; H, 4.82; N, 14.05.
JH8–H10 = 2.3 Hz, H-10), 7.61 (d, 1H,JH10–H11 = 8.7 Hz,
H-11), 7.75 (d, 1H, JH1–H2 = 5.5 Hz, H-2), 8.42 (d, 1H,
JH10–H8 = 2.3 Hz, H-8), 8.54 (d, 1H,JH1–H2 = 5.5 Hz,
H-1), 9.27 (br s, 1H, OH), 10.00 (s, 1H, H-4), 11.69 (s,
1H, NH), 12.01 (br s, 1H, NH); 13C NMR HSQC
(DMSO-d6) d 34.6 (NCH2), 44.3 (N(CH3)2), 56.3
(CH2NMe2), 107.3 (CH-10), 108.4 (CH-4), 112.1 (CH-
1), 116.5 (CH-2), 144.6 (CH-11), 145.2 (CH-8); MS
(MALDI) m/z: 414 [M+H]+. Anal. Calcd for
C23H19N5O3: C, 66.82; H, 4.63; N, 16.94. Found: C,
66.57.; H, 4.52; N, 17.11.
5.1.19. 10-Benzyloxy-6-(2-dimethylaminoethyl)-1H-pyr-
ido[3040:4,5]pyrrolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7(6H,
12H)-dione (34). Similar preparation as for 32 starting
from 28. Compound 34 was obtained as a red solid
(42 mg, 60%). Mp: >200 ꢁC; IR (film, cmꢀ1) m 1387
(C–O–C), 1691 (C@O), 3097–3355 (NH) 1H NMR
(DMSO-d6, 500 MHz) d 2.22 (s, 6H, N(CH3)2), 2.58 (t,
2H, J = 6.5 Hz, CH2NMe2), 3.78 (t, 2H, J = 6.5 Hz,
C(O)NCH2), 5.27 (s, 2H, CH2Ph), 7.06 (dd, 1H, JH9–
H11 = 1.9 Hz, JH9–H8 = 8.7 Hz, H-9), 7.37 (t, 1H,
J = 7.3 Hz, H arom), 7.41 (s, 1H, H-11), 7.44 (dd, 2H,
5.1.22. 3-(5-Benzyloxy-1H-indol-3-yl)-4-bromo-1H-pyr-
role-2,5-dione (38). Similarly prepared as for 3738 from
5-benzyloxyindole. Compound 38 was obtained as an
orange solid (1.4 g, 80%). Mp: 277–278 ꢁC; IR (KBr,
1
cmꢀ1) m 1704 (C@O), 3296 (NH); H NMR (DMSO-
d6) d 5.12 (s, 2H, CH2Ph), 6.95 (dd, 1H, JH6–H7
=
8.8 Hz,JH6–H4 = 2.4 Hz, H-6), 7.31–7.49 (m, 7H, H
arom, H-7, H-4), 7.97 (s, 1H, H-2), 11.29 (br s, 1H,
NH), 11.98 (br s, 1H, NH); 13C NMR (DMSO-d6)d
69.7 (CH2Ph), 103.6 (Cq), 106.1 (Cq), 106.1 (CH-7 or
CH-4), 113.0 (CH-7 or CH-4), 113.0 (CH-6), 113.6
(Cq), 127.5 (CH), 127.6 (2 CH), 128.4 (2 CH), 131.6
(CH-2 and Cq), 137.5 (Cq), 137.9 (Cq), 153.1 (Cq),
167.5 (C@O), 170.4 (C@O); MS (IS) m/z: 397 [M+H]+
79Br, 399 [M+H]+ 81Br. Anal. Calcd for C19H13BrN2O3:
C, 57.45; H, 3.30; N, 7.05. Found: C, 57.08.; H, 3.45;
N, 7.17.
J = 7.3 Hz, J = 7.5 Hz,
H
arom), 7.55 (d, 2H,
J = 7.5 Hz, H arom), 7.76 (d, 1H, JH1–H2 = 5.6 Hz, H-
2), 8.55 (d, 1H, JH1–H2 = 5.6 Hz, H-1), 8.81 (d, 1H,
JH9–H8 = 8.7 Hz, H-8), 9.99 (s, 1H, H-4), 11.77 (br s,
1H, NH), 12.07 (br s, 1H, NH); 13C NMR HSQC
(DMSO-d6)d 35.1 (CH2NMe2), 45.0 (N(CH3)2), 56.9
(NCH2), 69.2 (CH2Ph), 96.4 (CH-1), 107.1 (CH-10),
110.3 (CH-3), 125.0 (CH-4), 127.3 (CH), 127.3 (2 CH),
128.1 (2 CH), 144.7 (CH-8), 145.1 (CH-11); MS (MAL-
DI) m/z: 504 [M+H]+. Anal. Calcd for C30H25N5O3: C,
71.56; H, 5.00; N, 13.91. Found: C, 71.24; H, 5.17; N,
13.82.
5.1.23. 3-(6-Benzyloxy-1H-indol-3-yl)-4-bromo-1H-pyr-
role-2,5-dione (39). Similarly prepared as for 3738 from
6-benzyloxyindole. Compound 39was obtained as a
red solid (1.1 g, 76%). Mp: 151–152 ꢁC; IR (KBr, cmꢀ1)m
1
1714 (C@O), 3346 (NH); H NMR (DMSO-d6)d.15 (s,
2H, CH2Ph), 6.88 (dd, 1H, JH5–H4 = 8.8 Hz, JH5–H7
=
5.1.20. 1,3-Dioxolo[4,5-b]-6-(2-dimethylaminoethyl)-1
H-pyrido[30,40:4,5]pyrrolo[3,2-i]pyrrolo[3,4-g]carbazole-5,7
(6H,12H)-dione (35). Similar preparation as for 32 start-
ing from 29. Compound 35 was obtained as a brown-red
solid (71 mg, 62%). Mp: >200 ꢁC; IR (KBr, cmꢀ1) m
1036, 1134, 1468, 1691 (C@O), 3200–3450 (NH); 1H
NMR (DMSO-d6, 500 MHz) d 2.28 (s, 6H, N(CH3)2),
2.65 (t, 2H, J = 6.0 Hz, CH2NMe2), 3.78 (t, 2H,
J = 6.0 Hz, NCH2), 6.13 (s, 2H, OCH2O), 7.30 (s, 1H,
H-8), 7.70 (d, 1H, JH1–H2 = 6.1 Hz, H-2), 8.28 (s, 1H,
H-11), 8.51 (d, 1H, JH1–H2 = 6.1 Hz, H-1), 9.93 (s, 1H,
H-4), 11.87 (s, 1H, NH), 12.19 (br s, 1H, NH); 13C
HSQC (DMSO-d6) d 35.1 (NCH2), 44.8 (N(CH3)2),
56.8 (CH2NMe2), 92.9 (CH-4), 101.4 (OCH2O), 102.1
(CH-1), 107.3 (CH-10), 144.5 (CH-11), 145.8 (CH-8);
MS (MALDI) m/z: 442 [M+H]+. Anal. Calcd for
C24H19N5O4: C, 65.30; H, 4.34; N, 15.86. Found: C,
65.65; H, 4.50; N, 15.79.
2.5 Hz, H-5), 7.06 (d, 1H, JH5–H7 = 2.5 Hz, H-7), 7.32–
7.50 (m, 5H, CH), 7.82 (d, 1H, JH5–H4 = 8.8 Hz, H-4),
7.94 (s, 1H, H-2), 11.31 (br s, 1H, NH), 11.90 (br s,
1H, NH); 13C NMR (DMSO-d6) d 69.5 (CH2Ph), 96.5
(CH-7), 103.9 (Cq), 111.1 (CH-5), 113.9 (Cq), 118.8
(Cq), 123.1 (CH-4), 125.4 (Cq), 127.6 (2 CH), 127.7
(CH), 128.4 (2 CH), 130.3 (CH-2), 137.3 (Cq), 137.9
(Cq), 155.1 (Cq), 167.5 (C@O), 170.2 (C@O); MS
(IS+) m/z: 397 [M+H]+ 79Br, 399 [M+H]+ 81Br. Anal.
Calcd for C19H13BrN2O3: C, 57.45; H, 3.30; N, 7.05.
Found: C, 57.84; H, 3.13; N, 7.20.
5.1.24.
4-[1-(tert-Butyloxycarbonyl)-1H-pyrrolo[3,2-c]
pyridin-3-yl]-3-(1H-indol-3-yl)-1H-pyrrole-2,5-dione (40).
Similar preparation as for 14 starting from 37.38 Com-
pound 40 was isolated as an orange solid (1.1 g, 74%).
Mp: 198–199 ꢁC (dec); IR (Br, cmꢀ1) m 1152 (C–O–C),
1
1709 (C@O), 1739 (C@O), 2977 (CH), 3274 (NH); H
NMR (CDCl3) d 1.75 (s, 9H, C(CH3)3), 6.64-6.74 (m,
2H, CHi), 6.92–6.94 (m, 2H, CHi), 7.89 (s, 1H, H-2i),
8.01-8,03 (m, 2H, H-2a, H-6a), 8.17 (br s, 1H, NH),
8.29–8.31 (m, 2H, H-4a, H-7a), 11.70 (br s, 1H, NH);
13C NMR (CDCl3) d 28.3 (C(CH3)3); 86.0 (CMe3),
105.8 (Cq), 110.2 (CH-6a), 112.5 (CH), 120.6 (2 CH),
122.7 (CH), 122.9 (Cq), 125.7 (2 Cq), 129.0 (CH-4a),
130.4 (CH-2i), 133.2 (Cq), 136.6 (2 Cq), 139.5 (Cq),
143.1 (CH-7a), 143.8 (CH-2a), 148.8 (COOtBu), 171.4
5.1.21. 6-(2-Dimethylaminoethyl)-9-hydroxy-1H-pyrido
[3040:4,5]pyrrolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-(6H,
12H)-dione (36). Similar preparation as for 32 starting
from 30. Compound 36 was obtained as a brown-red so-
lid (28 mg, 48%). Mp: >250 ꢁC; IR (KBr, cmꢀ1)m 1386,
1
1691 (C@O); H NMR (DMSO-d6, 500 MHz) d 2.40
(s, 6H, N(CH3)2), 2.82 (m, 2H, CH2NMe2), 3.87 (t,
2H, J = 6.0 Hz, NCH2), 7.07 (dd, 1H, JH10–H11 = 8.7 Hz,

M. Lefoix et al. / Bioorg. Med. Chem. 16 (2008) 5303–5321
5317
(C@O), 171.7 (C@O); MS m/z: 429 [M+H]+, 373 [M+H-
7.8 Hz, JH9–H10 = 7.5 Hz, H-10), 7.73 (d, 1H, JH9–H8
=
7.8 Hz, H-8), 8.11 (d, 1H,JH1–H2 = 5.4 Hz, H-2), 8.69
(br s, 1H, H-1), 8.90 (d, 1H,JH10–H11 = 7.8 Hz, H-11),
9.90 (s, 1H, H-4), 11.26 (s, 1H, NH), 11.98 (s, 1H,
NH) 12.49 (br s, 1H, NH); 13C NMR HSQC (DMSO-
d6) d 109.0 (CH-10), 112.2 (CH-4), 120.9 (CH-3), 124.3
(CH-1), 127.7 (CH-2), 138.2 (CH-11), 140.0 (CH-8);
MS (MALDI) m/z: 327 [M+H]+. Anal. Calcd for
C19H10N4O2: C, 69.94; H, 3.09; N, 17.17. Found: C,
69.65; H, 3.23; N, 17. 29.
tert-butyl]+, 329 [M+H-Boc]+. Anal. Calcd for
C24H20N4O4: C, 67.28; H, 4.70; N, 13.08. Found: C,
67.53; H, 4.51; N, 13.22.
5.1.25.
3-(5-Benzyloxy-1H-indol-3-yl)-4-[1-(tert-butyl
oxycarbonyl)-1H-pyrrolo[3,2-c]pyridin-3-yl]-1H-pyrrole-
2,5-dione (41). Similar preparation as for 14 starting
from 38. Compound 41 was isolated as an orange solid
(1.6 g, 80%). Mp: 169–170 ꢁC; IR (KBr, cmꢀ1) m 1151
(C–O), 1710 (C@O), 1747 (C@O), 2914 (CH arom),
1
3238 (NH), 3436 (NH); H NMR (CDCl3) d 1.60 (s,
5.1.28. 9-Benzyloxy-1H-pyrido[3040:4,5]pyrrolo[2,3-a]pyr-
rolo[3,4-c]carbazole-5,7(6H,12H)-dione (44). Similar
preparation as for 26 starting from 41. Compound 44
was obtained as an orange solid (228 mg, 70%). Mp:
>250 ꢁC; IR (KBr, cmꢀ1) m 1326, 1712 (C@O), 1746
9H, C(CH3)3), 4.22 (s, 2H, CH2Ph), 6.18 (d, 1H,
JH4i–H6i = 1.7 Hz, H-4i), 6.56 (dd, 1H, JH6i–H7i = 8.8 Hz,
JH4i–H6i = 1.7 Hz, H-6i), 6.78 (d, 1H, JH6i–H7i = 8.8 Hz,
H-7i), 7.16–7.31 (m, 5H, H arom), 7.91 (d, 1H,
JH2i–NH = 2.6 Hz, H-2i), 8.04 (d, 1H, JH6a–H7a = 5.7 Hz,
H-6a), 8.12 (s, 1H, H-2a), 8.21 (s, 1H, H-4a), 8.31 (d,
1H, JH6a–H7a = 5.7 Hz, H-7a), 8.88 (br s, 1H, NH),
11.77 (br s, 1H, NH); 13C NMR (CDCl3) d 28.0
(C(CH3)3), 70.3 (CH2Ph), 86.0 (CMe3), 103.9 (CH-4i),
105.7 (Cq), 110.2 (CH-6a), 110.7 (Cq), 113.2 (CH-7i),
113.7 (CH-6i), 121.5 (Cq), 125.7 (Cq), 126.0 (Cq), 127.4
(2 CH), 127.9 (CH), 128.5 (2 CH), 128.6 (CH-4a), 131.2
(CH-2i), 131.7 (Cq), 133.8 (Cq), 137.0 (Cq), 139.4 (Cq),
143.3 (CH-7a), 143.8 (CH-2a), 148.6 (Cq), 153.6 (COOt-
Bu), 171.7 (C@O), 172.0 (C@O); MS m/z: 535 [M+H]+,
479 [M+H-tert-butyl]+, 435 [M+H-Boc]+. Anal. Calcd
for C31H26N4O5: C, 69.65; H, 4.90; N, 10.48. Found: C,
69.30; H, 5.04; N, 10.37.
1
(C@O), 3212 (NH); H NMR (DMSO-d6, 500 MHz) d
5.20 (CH2Ph), 7.18 (d, 1H, JH10–H11 = 8.0 Hz, H10),
7.34–7.43 (m, 3H, CH), 7.56 (d, 3H, JH10–H11 = 8.0 Hz,
H-11, H arom), 7.83 (br s, 1H, H-2), 8.50–8.54 (m,
2H, H-8, H-1), 9.87 (s, 1H, H-4), 11.08 (s, 1H, NH);
13C NMR HSQC (DMSO-d6) d 69.8 (CH2Ph), 107.5
(CH-4), 107.7 (CH-10), 112.9 (CH-1), 116.8 (CH-2),
128.0 (2 CH), 128.0 (CH), 128.4 (2 CH), 142.2 (CH-
11), 143.6 (CH-8); MS (MALDI) m/z: 433 [M+H]+.
Anal. Calcd for C26H16N4O3: C, 72.21; H, 3.73; N,
12.96. Found: C, 71.96; H, 3.60; N, 13.12.
5.1.29. 10-Benzyloxy-1H-pyrido[3040:4,5]pyrrolo[2,3-a]-
pyrrolo[3,4-c]carbazole-5,7-(6H,12H)-dione (45). Similar
preparation as for 26 starting from 42. Compound 45
was obtained as a yellow solid (141 mg, 86%). Mp:
>250 ꢁC; IR (KBr, cmꢀ1) m 1131, 1332, 1712 (C@O),
1748 (C@O), 3226 (NH), 3382 (NH); 1H NMR
(DMSO-d6, 500 MHz) d 5.24 (s, 2H, CH2Ph) 7.05 (d,
1H, JH8–H9 = 8.0 Hz, H-9), 7.34–7.44 (m, 4H, H arom,
H-11), 7.53 (d, 2H, J = 7.3 Hz, H arom), 7.90 (s, 1H,
H-2), 8.59 (s, 1H, H-1), 8.77 (d, 1H, JH8–H9 = 8.0 Hz,
H-8), 9.94 (br s, 1H, H-4), 11.10 (s, 1H, NH), 11.79 (s,
1H, NH); 13C NMR HSQC (DMSO-d6) d 69.6 (CH2Ph),
96.3 (CH-1), 107.8 (CH-10), 110.7 (CH-3), 125.1 (CH-
4), 127.7 (2 CH), 127.7 (CH), 128.5 (2 CH), 142.1
(CH-11), 143.3 (CH-8); MS (MALDI) m/z: 433
[M+H]+. Anal. Calcd for C26H16N4O3: C, 72.22; H,
3.73; N, 12.96. Found: C, 72.58; H, 3.59; N, 12.78.
5.1.26. 3-(6-Benzyloxy-1H-indol-3-yl)-4-[1-(tert-butyloxy
carbonyl)-1H-pyrrolo[3,2-c]pyridin-3-yl]-1H-pyrrole-2,5-
dione (42). Similar preparation as for 14 starting from
39. Compound 42 was isolated as a red solid (0.3 g,
28%). Mp: 149–150 ꢁC; IR (KBr, cmꢀ1) m 1148 (C–O–
C), 1358, 1714 (C@O), 1747 (C@O), 3150 (NH); 1H
NMR (CDCl3) d 1.71 (s, 9H, C(CH3)3), 4.74 (s, 2H,
CH2Ph), 6.36 (dd, 1H, JH5i–H4i = 8.7 Hz, JH5i–H7i
=
2.0 Hz, H-5i), 6.59–6.62 (m, 2H, H-4i, H-7i), 7.23–
7.27 (m, 5H, CH), 7.76 (d, 1H,JH2i–NH = 2,6 Hz, H-2i),
8.00 (d, 1H, JH6a–H7a = 5.8 Hz, H-6a), 8.13 (s, 1H, H-
2a), 8.20 (s, 1H, H-4a), 8.29 (d, 1H, JH6a–H7a = 5.8 Hz,
H-7a), 8.99 (br s, 1H, NH), 11.28 (br s, 1H, NH); 13C
NMR (CDCl3) d 28.3 (C(CH3)3), 70.3 (CH2Ph), 86.0
(CMe3), 96.6 (CH-7i), 106.0 (Cq), 110.1 (CH-6a),
111.3 (CH-5i), 120.0 (Cq), 121.4 (CH-4i), 122.8 (Cq),
127.6 (2 CH), 127.9 (CH), 128.6 (2 CH), 128.8 (CH-
4a), 129.0 (Cq), 129.6 (CH-2i), 132.3 (Cq), 133.2 (Cq),
137.2 (Cq), 137.4 (Cq), 139.5 (Cq), 143.4 (CH-7a),
144.0 (CH-2a), 148.8 (Cq), 155.8 (COOtBu), 171.3
(C@O), 171.6 (C@O); MS (IS) m/z: 535 [M+H]+, 479
[M+H-tert-butyl]+, 435 [M+H-Boc]+. Anal. Calcd for
C31H26N4O5: C, 69.65; H, 4.90; N, 10.48. Found: C,
70.02.; H, 5.04; N, 10.31.
5.1.30. 9-Hydroxy-1H-pyrido[3040:4,5]pyrrolo[2,3-a]pyr-
rolo[3,4-c]carbazole-5,7-(6H,12H)-dione (46). Similar
preparation as for 30 starting from 44. Compound 46
was obtained as a red solid (22 mg, 71%). Mp:
>250 ꢁC; IR (KBr, cmꢀ1) m 1328 (C–O–C), 1714
(C@O), 1757 (C@O), 3198 (NH, OH), 3424 (NH,
1
OH); H NMR (DMSO-d6, 500 MHz) d 7.08 (dd, 1H,
JH10–H11 = 8.7 Hz, JH8–H10 = 2.3 Hz, H-10), 7.61 (d,
=
1H,JH10–H11 = 8.7 Hz, H-11), 8.25 (d, 1H, JH1–H2
6.6 Hz, H-2), 8.27 (d, 1H, JH8–H10 = 2.3 Hz, H-8), 8.75
(d, 1H,JH1–H2 = 6.6 Hz, H-1), 9.34 (s, 1H, H-4), 9.87 (s,
1H, OH), 11.24 (s, 1H, NH), 11.73 (s, 1H, NH), 13.11
(br s, 1H, NH); 13C NMR HSQC (DMSO-d6)d 108.5
(CH-4), 109.8 (CH-10), 112.8 (CH-1), 118.0 (CH-2),
135.8 (CH-11), 137.8 (CH-8); MS (MALDI) m/z: 343
[M+H]+. Anal. Calcd for C19H10N4O3: C, 66.67; H,
2.94; N, 16.37. Found: C, 66.33; H, 3.07; N, 16.53.
5.1.27. 1H-pyrido[3040:4,5]pyrrolo[2,3-a]pyrrolo[3,4-c]-
carbazole-5,7-(6H,12H)-dione (43). Similar preparation
as for 26 starting from 40. Compound 43 was obtained
as a yellow solid (319 mg, 85%). Mp: >250 ꢁC; IR (KBr,
1
cmꢀ1) m 1242, 1718 (C@O), 3100–3330 (NH); H NMR
(DMSO-d6, 500 MHz) d 7.37 (dd, 1H, JH9–H8 = 7.8 Hz,
JH9–H10 = 7.5 Hz, H-9), 7.56 (dd, 1H, JH10–H11
=

5318
M. Lefoix et al. / Bioorg. Med. Chem. 16 (2008) 5303–5321
5.1.31. 10-Hydroxy-1H-pyrido[3040:4,5]pyrrolo[2,3-a]pyr-
rolo[3,4-c]carbazole-5,7-(6H,12H)-dione (47). Similar
preparation as for 30 starting from 45. Compound 47
was obtained as a yellow solid (33 mg, 88%). Mp:
>250 ꢁC; IR (KBr, cmꢀ1) m 1329 (C–O–C), 1712
(C@O), 1756 (C@O), 3212 (NH, OH); 1H NMR
(DMSO-d6, 500 MHz) d 6.89 (dd, 1H, JH8–H9 = 8.6 Hz,
JH9–H11 = 1.7 Hz, H-9), 7.15 (s, 1H, H-11), 8.26 (d,
4.20 (d, 1H, J = 10.2 Hz, CH2Ph), 4.53 (d, 1H,
J = 12.0 Hz, CH2Ph), 4.65 (d, 1H, J = 12.0 Hz, CH2Ph),
4.67 (d, 1H, J = 10.7 Hz, CH2Ph), 4.88 (d, 1H,
J = 11.0 Hz, CH2Ph), 4.89 (d, 1H, J = 10.7 Hz, CH2Ph),
4,93 (d, 1H, J = 11.0 Hz, CH2Ph), 5.45 (d,
1H,JH1 –H2 ¼ 8:8 Hz, H-10), 6.65 (d, 1H, J = 3.8 Hz,
CH), 6.68 (d, 2H, CH), 6.74-6.76 (m, 2H, CH), 6.99–
7.10 (m, 4H, CH), 7.19–7.34 (m, 16H, CH), 7.52 (d,
1H, J = 8.5 Hz, CH), 7.61 (d, 1H, J = 4.1 Hz, CH),
8.05 (s, 1H, H-2a), 8.18 (s, 1H, H-4a); 13C NMR
(CDCl3) d 24.5 (NCH3), 28.2 (C(CH3)3), 68.5 (C-60),
73.7 (CH2Ph), 75.1 (CH2Ph), 75.4 (CH2Ph), 75.8
(CH2Ph), 77.5 (CH sugar), 78.2 (CH sugar), 81.6 (CH
sugar), 85.4 (C-20), 85.6 (CMe3), 86.5 (C-10), 106.7
(Cq), 110.2 (Cq), 112.2 (CH), 121.4 (CH), 121.7 (CH),
123.3 (CH), 123.5 (Cq), 126.0 (CH), 126.3 (Cq), 127.7
(CH), 127.8 (CH), 127.8 (Cq), 127.9 (CH), 128.0 (CH),
128.1 (CH), 128.2 (CH), 128.5 (CH), 128.5 (CH), 128.6
(CH), 128.6 (CH), 128.8 (CH), 131.1 (CH-4a), 131.8
(Cq), 132.1 (Cq), 136.1 (Cq), 137.0 (Cq), 138.1 (Cq),
138.2 (Cq), 138.5 (Cq), 148.8 (COOtBu), 171.4 (C@O),
171.6 (C@O); MS (IS) m/z: 966 [M+H]+. Anal. Calcd
for C59H56N4O9: C, 73.43; H, 5.85; N, 5.81. Found: C,
73.81; H, 5.66; N, 5.63.
0
0
1H,JH1–H2 = 6.5 Hz, H-2), 8.72 (d, 1H, JH8–H9
=
8.6 Hz, H-8), 8.77 (d, 1H, JH1–H2 = 6.5 Hz, H-1), 9.96
(s, 1H, H-4), 9.98 (s, 1H, OH), 11.27 (s, 1H, NH),
11.80 (s, 1H, NH), 13.05 (br s, 1H, NH); 13C NMR
(HSQC DMSO-d6)d 97.3 (CH-1), 109.4 (CH-10), 111.2
(CH-3), 125.2 (CH-4), 136.6 (CH-11), 138.2 (CH-8);
MS (MALDI) m/z: 343 [M+H]+. Anal. Calcd for
C19H10N4O3: C, 66.67; H, 2.94; N, 16.37. Found: C,
66.92.; H, 2.80; N, 16.21.
5.1.32. 9-Benzyloxy-3-methyl-1H-pyrido[30,40:4,5]pyrrol-
o[2,3-a]pyrrolo[3,4-c]carbazole-5,7(6H,12H)-dione-3-ium
iodide (49). A solution of 44 (48 mg, 0.11 mmol) and
iodomethane (0.50 mL) in DMF (1 mL) was heated at
60 ꢁC for 24 h in a sealed tube. After cooling and evap-
oration, the residue was taken in methanol (1 mL) and
filtered to afford compound 49 as a yellow solid
(23 mg, 37%). Mp: >250 ꢁC; IR (KBr, cmꢀ1)m 1329
(C–O–C), 1712 (C@O), 1756 (C@O), 3210 (NH, OH),
3418 (NH, OH); 1H NMR (DMSO-d6, 500 MHz) d 4.48
(s, 3H, N+CH3), 5.25 (s, 2H, CH2Ph), 7.33–7.37 (m, 2H,
H arom, H-10), 7.43 (dd, 2H, J = 7.4 Hz, J = 7.6 Hz, H
arom), 7.58 (d, 2H, J = 7.4 Hz, H arom), 7.76 (d,
5.1.34. 1-Methyl-3-[1-(2,3,4,6-tetra-O-benzyl-b-D-gluco
pyranosyl)-1H-indol-3-yl]-4-[1H-pyrrolo[3,2-c]pyridin-3-
yl]pyrrole-2,5-dione (53). A solution of compound 52
(495 mg, 0.51 mmol) in formic acid (10 mL) was stirred
overnight at room temperature. After evaporation, the
residue was dissolved in EtOAc (25 mL) and washed
with a 20% aqueous solution of Na2CO3 till pH 7 to af-
ford after evaporation compound 53 as a red-orange so-
lid (437 mg, 99%). Mp: 115–116 ꢁC; IR (KBr, cmꢀ1) m
1084, 1694 (C@O), 3441 (NH); 1H NMR (CDCl3) d
3.14 (s, 3H, NCH3), 3.67 (d, 1H, J = 10.0 Hz, CH2Ph),
1H,JH10–H11 = 8.8 Hz, H-11), 8.29 (d, 1H, JH1–H2
6.7 Hz, H-2), 8.58 (s, 1H, H-8), 8.74 (d, 1H, JH1–H2
=
=
6.7 Hz, H-1), 9.85 (s, 1H, H-4), 11.34 (s, 1H, NH) 13.23
(br s, 1H, NH); 13C NMR HSQC (DMSO-d6)d 47.0
(N+CH3), 69.4 (CH2Ph), 107.5 (CH-4), 110.1 (CH-10),
113.2 (CH-1), 117.7 (CH-2), 127.8 (2 CH), 127.9 (CH),
128.4 (2 CH), 138.9 (CH-11), 140.9 (CH-8); MS (MAL-
DI)m/z: 447 [MꢀI]. Anal. Calcd for C27H19IN4O3: C,
56.46; H, 3.33; N, 9.75. Found: C, 56.78; H, 3.17; N, 9.64.
3.73-3.81 (m, 2H,
2 CH sugar), 3.87 (d, 1H,
J = 8.8 Hz, CH2Ph), 3.92 (d, 1H, J = 8.8 Hz, CH2Ph),
4.00–4.08 (m, 2H, H-20, CH sugar), 4.20 (d, 1H,
J = 10.0 Hz, CH2Ph), 4.46 (d, 1H, J = 12.2 Hz, CH2Ph),
4.56 (d, 1H, J = 12.2 Hz, CH2Ph), 4.65 (d, 1H, J = 10.
7 Hz, CH2Ph), 4.85–4.95 (m, 3H, CH2Ph), 5.48 (d,
5.1.33. 1-Methyl-3-[1-(2,3,4,6-tetra-O-benzyl-b-D-gluco
pyranosyl)-1H-indol-3-yl]-4-[1-(tert-butyloxycarbonyl)-
1H,JH1 –H2 ¼ 8:5 Hz, H-10), 6.50 (d, 1H, JH4i–
H5i = 8.2 Hz, H-4i), 6.62–6.70 (m, 3H, H-5i, 2H arom),
6.96–7.05 (m, 5H, H-6i, 4H arom), 7.18–7.30 (m, 14
H, H arom), 7.38 (d, 1H, JH6a–H7a = 6.0 Hz, H-6a),
7.51 (d, 1H, JH7i–H6i = 8.5 Hz, H-7i), 7.57 (s, 1H, H-
2i), 7.91 (d, 1H,JH6a–H7a = 6.0 Hz, H-7a), 8.11 (s, 1H,
H-2a), 8.55 (s, 1H, H-4a), 10.10 (br s, 1H, NH); 13C
NMR (CDCl3)d 24.4 (NCH3), 68.6 (CH2), 73.5 (CH2),
75.0 (CH2), 75.3 (CH2), 75.7 (CH2), 77.4 (CH sugar),
77.9 (CH sugar), 81.4 (CH sugar), 85.4 (CH sugar),
86.1 (CH-10 sugar), 106.4 (Cq), 107.2 (Cq), 108.6 (CH-
6a), 111.9 (CH-7i), 121.2 (CH-5i), 122.0 (CH-4i), 122.8
(Cq), 123.2 (CH-6i), 125.3 (Cq), 127.7 (CH), 127.8
(CH), 127.8 (CH), 128.0 (CH), 128.1 (CH), 128.2
(CH), 128.5 (CH), 128.5 (CH), 128.6 (CH), 128.7
(CH), 129.0 (CH), 130.8 (CH-2a), 132.1 (CH-2i), 135.9
(CH-7a), 136.2 (Cq), 136.9 (Cq), 138.0 (Cq), 138.4
(Cq), 141.0 (CH-4a), 141.4 (Cq), 171.5 (C@O), 171.9
(C@O); MS (IS +) m/z: 866 [M+H]+. Anal. Calcd for
C54H48N4O7: C, 74.98; H, 5.59; N, 6.48. Found: C,
74.67; H, 5.75; N, 6.66.
0
0
1H-pyrrolo[3,2-c]pyridin-3-yl]pyrrole-2,5-dione
(52).
Method A: Similar preparation as for 14, starting from
51.39 After a flash chromatography (petroleum ether/
EtOAc 7:3), compound 52 was obtained as a red solid
(524 mg, 35%). Method B: To a solution of compound
14 (0.100 g, 0.23 mmol) in THF (3 mL), 2,3,4,6-tetra-
O-benzyl-sc d-glucopyranoside 50 (0.184 g, 0.34 mmol)
and PPh3 (0.181 g, 0.69 mmol) were added. After cool-
ing to 0 ꢁC, DIAD (0.136 mL, 0.69 mmol) was added.
The mixture was stirred for 1 h at room temperature,
hydrolyzed with water (10 mL) and extracted with
EtOAc (3· 20 mL). The combined organic layers were
washed with brine and evaporated. The residue was
purified by flash chromatography on a silica gel column
(petroleum ether/EtOAc 7:3) to yield 52 a red solid
(73 mg, 33%). Mp: 75–76 ꢁC; IR (KBr, cmꢀ1) m 1703
(C@O), 1736 (C@O), 2924 (CH arom); 1H NMR
(CDCl3) d 1.66 (s, 9H, C(CH3)3), 3.22 (s, 3H, NCH3),
3.66 (d, 1H, J = 10.2 Hz, CH2Ph), 3.71–3.77 (m, 1H,
CH sugar), 3.81–4.03 (m, 5H, H-20, H-60, 2CH sugar),

M. Lefoix et al. / Bioorg. Med. Chem. 16 (2008) 5303–5321
5319
5.1.35. 6-Methyl-12-(2,3,4,6-tetra-O-benzyl-b-D-gluco
pyranosyl)-1H-pyrido[3040:4,5]pyrrolo[2,3-a]pyrrolo[3,4-c]
carbazole-5,7-(6H,12H)-dione (54). Similar preparation
as for 26 starting from 53. Compound 54 was obtained
as an orange solid (214 mg, 69%). Mp: 108–109 ꢁC; IR
(KBr, cmꢀ1) m 1076 (C–O–C), 1698 (C@O), 3444
H-1), 10.25 (s, 1H, H-4), 12.86 (s, 1H, NH); 13C NMR
(DMSO-d6) d 23.7 (NCH3), 58.2 (CH-60), 62.3 (CH2Ph),
67.2 (CH-40), 73.5 (CH-20), 76.6 (CH-30), 78.8 (CH-50),
84.3 (CH-10), 109.6 (CH-10), 112.8 (CH-4), 121.4 (CH-
2), 124.5 (CH-1), 128.0 (CH-3), 128.2 (2 CH), 129.6 (2
CH), 129.6 (CH), 140.0 (CH-11), 140.8 (CH-8); MS
(MALDI) m/z: 594 [MꢀBr]+.
1
(NH); H NMR (CDCl3) d 3.30 (s, 3H, NCH3), 3.33
(d, 1H, J = 11.3 Hz, CH2Ph), 3.80 (d, 1H, J = 11.3 Hz,
CH2Ph), 3.97–3.99 (m, 2H, H-60), 4.06–4.11 (m, 2H,
H-30 and H-40), 4.26–4.29 (m, 1H, H-50), 4.38 (dd, 1H,
5.1.37. 3-Benzyl-6-methyl-12-(2,3,4,6-tetra-O-acetyl-b-D-
glucopyranosyl)-1H-pyrido[30,40:4,5]pyrrolo[2,3-a]pyrrolo
[3,4-c]carbazole-5,7-(6H,12H)dione-3-ium bromide (56).
A solution of compound 55 (173 mg, 0.26 mmol) in pyr-
idine/acetic anhydride (4/2 mL) was stirred at room tem-
perature for 24 h. After the addition of toluene (5 mL),
the mixture was evaporated in vacuo and the residue
was purified by flash chromatography on a silica gel col-
umn (EtOAc) to yield 56 as a yellow solid (52 mg, 24%).
Mp: 148–150 ꢁC; 1H NMR (DMSO-d6, 500 MHz) d 1.01
(s, 3H, COCH3-20), 1.98 (s, 3H, COCH3-30), 2.14 (s, 3H,
COCH3-40), 2.15 (s, 3H, COCH3-60), 3.32 (s, 3H,
NCH3), 4.47-4.45 (m, 3H, H-60, H-50), 5.13 (d, 1H,
J = 15.0 Hz, CH2Ph), 5.30 (d, 1H, J = 15.0 Hz, CH2Ph),
JH2 –H3 ¼ 7:8 Hz, JH1 –H2 ¼ 9:0 Hz, H-20), 4.56 (d, 1H,
J = 12.0 Hz, CH2Ph), 4.68 (d, 1H, J = 12.0 Hz, CH2Ph),
4.76 (d, 1H, J = 11.0 Hz, CH2Ph), 4.82 (s, 2H, CH2Ph),
4.98 (d, 1H, J = 11.0 Hz, CH2Ph), 6.12 (d, 2H, JH4–
H3 = 7.2 Hz, H-8 and H arom), 6.61 (m, 2H, H-9 and
H-11), 6.81 (dd, 1H, J = 7.5 Hz, J = 7.2 Hz, H-10),
6.96–7.00 (m, 2H, CH), 7.19–7.57 (m, 17 H, H-2 and
16 H arom), 8.02 (d, 1H,J = 6.9 Hz, H arom), 8.08–
8.11 (m, 2H, H-10), 9.24 (s, 1H, H-4), 9.28 (d, 1H,
JH1–H2 = 7.2 Hz, H-1); 13C NMR (CDCl3) d 23.8
(NCH3), 69.3 (CH-60), 73.5 (CH2Ph), 73.8 (CH2Ph),
75.3 (CH2Ph), 75.8 (CH2Ph), 77.4 (CH-50), 78.3 (CH-
40), 79.0 (CH-20), 85.6 (CH-10), 85.9 (CH-30), 114.0
(CH), 114.2 (CH), 117.2 (Cq), 117.8 (Cq), 118.2 (Cq),
120.4 (Cq), 121.4 (CH), 121.5 (Cq), 123.7 (Cq), 125.7
(CH-11), 126.7 (CH-10), 127.1 (CH), 127.3 (CH),
127.6 (CH), 127.7 (CH), 127.8 (CH), 127.9 (CH), 128.1
(CH), 128.4 (CH), 128.5 (CH), 128.6 (CH), 128.9
(CH), 129.3 (CH), 132.0 (CH), 132.1 (Cq), 132.3 (Cq),
133.8 (Cq), 135.3 (Cq), 136. 8 (CH-8), 137.1 (Cq),
138.5 (Cq), 138.7 (Cq), 139.7 (Cq), 170.8 (C@O), 171.3
(C@O). Anal. Calcd for C54H46N4O7: C, 75.16; H,
5.37; N, 6.49. Found: C, 75.48; H, 5.19; N, 6.68.
0
0
0
0
5.49 (dd, 1H, JH4 –H5 ¼ 9:8 Hz, JH4 –H3 ¼ 9:6 Hz, H-40),
0
0
0
0
5.75 (dd, 1H, JH3 –H2 ¼ 9:4 Hz, JH4 –H3 ¼ 9:6 Hz, H-30),
0
0
0
0
5.93 (dd, 1H, JH2 –H1 ¼ 9:2 Hz, JH3 –H2 ¼ 9:4 Hz, H-20),
7.19 (d, 2H, J = 7.8 Hz, CH) Hz, 7.20–7.38 (m, 3H, H
arom), 7.42 (d, 1H, JH1–H2 = 7.5 Hz, H-2), 7.46 (dd,
1H, JH9–H10 = 7.3 Hz, JH10–H11 = 8.0 Hz, H-10), 7.60
(dd, 1H, JH8–H9 = 7.1 Hz, JH9–H10 = 7.3 Hz, H-9), 7.67
0
0
0
0
(d, 1H, JH8–H9 = 7.1 Hz, H-8), 7.98 (d, 1H, JH10–H11
=
8.0 Hz, H-11), 8.31 (d, 1H, JH2 ꢀH1 ¼ 9:2 Hz, H-10),
9.22 (d, 1H, JH1–H2 = 7.5 Hz, H-1), 9.54 (s, 1H, H-4),
12.48 (s, 1H, NH); 13C NMR HSQC (DMSO-d6) d
0
0
0
0
0
19.5 ðCOCH3 2 Þ, 20.7 ðCOCH3 3 Þ, 20.8 ðCOCH3 4 Þ,
0
0
5.1.36. 3-Benzyl-12-(b-D-glucopyranosyl)-6-methyl-1H-
pyrido[30,40:4,5]pyrrolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7
(6H,12H)-dione-3-ium bromide (55). To a cooled solu-
tion of compound 54 (0.292 g, 0.34 mmol) in CH2Cl2
(2 mL), at ꢀ78 ꢁC under nitrogen was added a 1 M solu-
tion of BBr3 in dichloromethane (1.68 mL, 1.68 mmol).
After 1 h at ꢀ78 ꢁC, addition of water (5 mL) at
ꢀ70 ꢁC led to a precipitate, which was filtered off. The
solid was washed several times with methanol (3·
10 mL) and the filtrate was concentrated to 0.5 mL to
afford a suspension. After filtration, the powder was dis-
solved with a small amount of methanol and the addi-
tion of EtOAc gave a precipitate. The obtained solid
was washed with diethyl ether to yield 55 as a yellow so-
lid (131 mg, 57%). Mp: >250 ꢁC; IR (film, cmꢀ1) m 1225,
20.8 ðCOCH3 6 Þ, 23.9 (NCH3), 62.3 (CH-6 ), 62.4
(CH2Ph), 68.9 (CH-40), 69.2 (CH-20), 73.7 (CH-30),
74.4 (CH-50), 84.3 (CH-10), 113.5 (CH-1), 113.7 (CH-
4), 121.6 (CH-2), 125.5 (CH-11), 127.1 (CH-3), 127.6
(2 CH), 129.2 (3 CH), 132.0 (CH-10), 137.1 (CH-8),
168.5 (COCH320), 169.3 (COCH340), 170.3 (COCH3-
30), 170.9 (2 C@O), 171.1 (COCH3-60). MS (MALDI)
m/z:761.8 [MꢀBr]+. Anal. Calcd for C41H37BrN4O11:
C, 58.51; H, 4.43; N, 6.66. Found: C, 58.15; H, 4.60;
N, 6.84.
5.1.38. 3-Benzyl-6-methyl-12-(3,4,6-tri-O-acetyl-b-D-glu-
copyranosyl)-1H-pyrido[30,40:4,5]pyrrolo[2,3-a]pyrrolo-
[3,4-c]carbazole-5,7(6H,12H)-dione-3-ium bromide (57).
Compound 57 was isolated during the synthesis of 56
and was purified by flash chromatography (EtOAc) as
a yellow solid. (40 mg, 19%). Mp: >250 ꢁC; IR (film;
cmꢀ1)m1043, 1227, 1688 (C@O), 1745 (C@O), 2919
1
1376, 1696 (C@O), 1749 (C@O), 3156–3689 (NH); H
NMR (DMSO-d6) d 3.21 (s, 3H, NCH3), 3.35–3.39 (m,
1H, H-20), 3.64 (dd, 1H, JH2 –H3 ¼ 8:8 Hz,
0
0
1
0
0
JH3 –H4 ¼ 9:1 Hz,
H-30),
3.87–3.96
(dd,
1H,
(CH arom); H NMR (DMSO-d6, 500 MHz) d 1.98 (s,
JH6 a–H5 ¼ 2:8 Hz, JH6 a–H6 b ¼ 9:6 Hz, H-60a), 3.93 (dd,
3H, COCH3), 2.01 (s, 3H, COCH3), 2.08 (s, 3H,
COCH3), 3.18 (s, 3H, NCH3), 4.23–4.29 (m, 3H, H-60
and H-50), 4.52–4.57 (m, 1H, H-20), 5.26 (dd, 1H,
0
0
0
0
1H, JH5 –H4 ¼ 9:6 Hz, H-40), 4.04 (dd, 1H,
0
0
JH6 a–H5 ¼ 2:8 Hz, JH5 –H4 ¼ 9:6 Hz, H-50), 4.13 (dd,
0
0
0
0
1H, JH6 b–H5 ¼ 2:8 Hz, JH6 a–H6 b ¼ 9:6 Hz, H-60b), 4,98
(br s, 1H, OH), 5.19 (br s, 1H, OH), 5.44 (br s, 1H,
OH), 6.09 (s, 2H, CH2Ph), 6.42 (d, 2H,
JH3 –H4 ¼ 9:3 Hz, JH3 –H2 ¼ 9:5 Hz, H-30), 5.34 (dd,
0
0
0
0
0
0
0
0
1H, JH4 –H5 ¼ 9:4 Hz, JH3 –H4 ¼ 9:3 Hz, H-40), 5.60 (d,
0
0
0
0
0
1H, JOH–H2 ¼ 5:2 Hz, OH), 5.84 (s, 2H, CH2Ph), 7.38–
JH1 –H2 ¼ 9:0 Hz, H-10 and OH), 7.43–7.54 (m, 6H, H
7.48 (m, 6H, 5H arom, H-10), 7.56 (dd, 1H, JH8–H9
7.2 Hz, JH9–H10 = 7.2 Hz, H-9), 7.96 (d, 1H, JH1–H2
=
=
0
0
arom, H-10), 7.68 (dd, 1H, JH8–H9 = 8.2 Hz, JH9–H10
=
7.2 Hz, H-9), 8,06 (d, 1H, JH8–H9 = 8.2 Hz, H-8), 8.11
(d, 1H,JH1–H2 = 7.2 Hz, H-2), 9.13-9.16 (m, 2H, H-11,
7.1 Hz, H-1), 8.08 (d, 1H, JH8–H9 = 7.2 Hz, H-8), 8.17
(d, 1H, JH1 –H2 ¼ 9:2 Hz, H-10), 8.44 (dd, 1H,
0
0

5320
M. Lefoix et al. / Bioorg. Med. Chem. 16 (2008) 5303–5321
6. Bartlett, S.; Beddard, G. S.; Jackson, R. M.; Kayser, V.;
Kilner, C.; Leach, A.; Nelson, A.; Oledzki, P. R.; Parker,
P.; Reid, G. D.; Warriner, S. L. J. Am. Chem. Soc. 2005,
127, 11699–11708.
JH2–H4 = 1.4 Hz, H-2), 9.12 (d, 1H, JH10–H11 = 7.9 Hz,
H-11), 9.84 (s, 1H, H-4), 12.57 (s, 1H, NH); 13C NMR
HSQC (DMSO-d6) d 20.1 (COCH3), 20.1 (COCH3),
20.2 (COCH3), 23.3 (NCH3), 60.5 (CH2Ph), 62.0 (CH-
60), 67.5 (CH-20), 68.1 (CH-40), 73.5 (CH-50), 75.5
(CH-30), 85.6 (CH-10), 113.1 (CH-11), 113.9 (CH-4),
120.5 (CH-2), 124.1 (CH-1), 126.0 (CH-3), 127.3 (CH),
128.3 (2 CH), 128.9 (2 CH), 134.1 (CH-10), 137.6
(CH-8), 169.5 (COCH3), 169.5 (COCH3), 170.0 (2
C@O), 170.1 (COCH3); MS (IS) m/z: 719.5 [M-Br]+.
Anal. Calcd for C39H35BrN4O10: C, 58.58; H, 4.41; N,
7.01. Found: C, 58.93; H, 4.24; N, 7.12.
7. Balasubramanian, B. N.; St. Laurent, D. R.; Saulnier, M.
G.; Long, B. H.; Bachand, C.; Beaulieu, F.; Clarke, W.;
Deshpande, M.; Eummer, J.; Fairchild, C. R.; Frennesson,
D. B.; Kramer, R.; Lee, F. Y.; Mahler, M.; Martel, A.;
Naidu, B. N.; Rose, W. C.; Russell, J.; Ruediger, E.;
Solomon, C.; Stoffan, K. M.; Wong, H.; Zimmermann,
K.; Vyas, D. M. J. Med. Chem. 2004, 47, 1609–1612.
8. (a) Yoshinari, T.; Ohkubo, M.; Fukasawa, K.; Egashira,
S.; Hara, Y.; Matsumoto, M.; Nakai, K.; Arakawa, H.;
Morishima, H.; Nishimura, S. Cancer Res. 1999, 59, 4271–
4275; (b) Arakawa, H.; Morita, M.; Kodera, T.; Okura,
A.; Ohkubo, M.; Morishima, H.; Nishimura, S. Jpn. J.
Cancer Res. 1999, 90, 1163–1170.
5.2. Pharmacology
5.2.1. Chk1 inhibition. Human Chk1 full-length enzyme
with an N-terminal GST sequence was either purchased
from Upstate Biochemicals (No. 14-346) or purified
from extracts of Sf9 cells infected with a baculovirus
encoding GST-Chk1. Assays for compound testing were
based upon the method described by Davies.42
9. Zhu, G.; Conner, S. E.; Zhou, X.; Shih, C.; Li, T.;
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10 mM Hepes buffer (pH 7.4). Cytotoxicity was mea-
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tions of compound (nine serial dilutions in triplicate)
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´
M.; Tome, F. Synlett 2000, 832–834.
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`
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´
12. Routier, S.; Coudert, G.; Merour, J. Y.; Caignard, D. H.
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´
13. Routier, S.; Ayerbe, N.; Merour, J. Y.; Coudert, G.;
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Renard, P. Tetrahedron 2002, 58, 6621–6630.
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14. (a) Marminon, C.; Pierre, A.; Pfeiffer, B.; Perez, V.;
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´
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5.2.3. Cell cycle analysis44,45. L1210 cells (2.5 · 105 cells/
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