Syntheses and antiproliferative activities of rebeccamycin analogues bearing two 7-azaindole moieties

Article abstract of DOI:10.1016/S0968-0896(02)00532-1

As a part of structure-activity relationship studies on rebeccamycin analogues, compounds containing two aza-indole moieties were synthesized bearing either a methyl group or a hydrogen atom on the imide nitrogen. The azaindole substructures were expected

Full text of DOI:10.1016/S0968-0896(02)00532-1

Bioorganic & Medicinal Chemistry 11 (2003) 679–687
Syntheses and Antiproliferative Activities of Rebeccamycin
Analogues Bearing Two 7-Azaindole Moieties
Christelle Marminon,a Alain Pierre,b Bruno Pfeiffer,c Valerie Perez,b Stephane Leonce,b
Pierre Renardc and Michelle Prudhommea,*
a
´
`
`
`
´ ˆ
`
Universite Blaise Pascal, Synthese Et Etude de Systemes a Interet Biologique, UMR 6504, 63177 Aubiere, France
b
´
Institut de Recherches SERVIER, Division de Cancerologie, 11 rue des Moulineaux, 92150 Suresnes, France
c
´
Les Laboratoires SERVIER, 1 rue Carle Hebert, 92415Courbevoie, France
Received 18 July 2002; accepted 18 October 2002
Abstract—As a part of structure–activity relationship studies on rebeccamycin analogues, compounds containing two aza-indole
moieties were synthesized bearing either a methyl group or a hydrogen atom on the imide nitrogen. The azaindole substructures
were expected to enhance the cytotoxicity toward tumor cell lines through stronger hydrogen bonding with the target enzyme(s).
The cytotoxicities of compounds 8, 10 and 19 against a panel of tumor cell lines were examined and compared with those of
rebeccamycin, dechlorinated rebeccamycin 2 and N-methylated analogue A. Their effect on the L1210 cell cycle was also evaluated.
Compound 19, having an imide NH function had the strongest cytotoxicity towards L1210 cells and induced the largest accumu-
lation of cells in the G2+M phases of the cell cycle. In contrast to their non-aza analogues, which were cytotoxic for all the cell
lines tested, diaza compounds 10 and 19 showed selectivity for some cell lines.
# 2002 Elsevier Science Ltd. All rights reserved.
Introduction
as various pharmaceutical agents such as anti-inflam-
matory and anti-psychotic agents. 7-Aza-indoles are
found in several natural products such as variolins,
compounds isolated from Antarctic sponge Kirk-patri-
ckia varialosa9 which exhibit antiproliferative activity
against murine leukemia P388 cell lines. Over the past
few years, the chemistry and biological applications of
7-aza-indoles have been widely investigated.10ꢀ13 New
NADH models in the pyrrolo[2,3-b] pyridine series and
7-azaindole derivatives with high affinity for the dopa-
mine D4 receptor have been synthesized. The syntheses
of 7-azaindole analogues of natural products such as
melatonin, vincamin, ellipticin, tryptophan have been
described.14ꢀ16 In 7-aza-rebeccamycin analogues, the
replacement of carbon atoms by nitrogen atoms intro-
duces a basic character into the molecule that can
modify the pharmacological properties. These nitrogen
atoms may also contribute to the formation of hydro-
gen bonds within the active site of target enzyme(s) and/
or DNA and thereby stabilize or modify the orientation
of the drug in the drug-enzyme complexes.
Rebeccamycin, a microbial metabolite isolated from cul-
tures of Saccharothrix aerocolonigenes, is an antitumor
antibiotic that inhibits topoisomerase I by stabilizing the
topoisomerase I-DNA cleavable complex.1,2 However,
its toxicity prohibits its use in cancer chemotherapy.
Structure–activity relationship studies have been carried
out with a view to improve the pharmacological profile
of rebeccamycin,3ꢀ7 and have led to the development of
a schematic representation of a drug-topoisomerase
I-DNA ternary complex. According to this model, the
indolocarbazole chromophore intercalates with DNA and
the carbohydrate side chain is oriented toward the minor
groove, while the imide part occupies a recognition
pocket of topoisomerase I.8 It has been showed that
although topoisomerase I is a target for most of rebec-
camycin derivatives, the inhibition of other enzymes
may also be a contributing factor to their cytotoxicity.
Azaindoles, as biosteres for indoles, present consider-
able biological importance. Azaindoles have been used
In this paper, we present the syntheses of rebeccamycin
analogues bearing two 7-azaindole moieties, in some
cases substituted with a methyl group on the imide
nitrogen (Fig. 1). Their antiproliferative activities in
*Corresponding author. Tel.: +33-473-40-71-24; fax: +33-473-40-77-
17; e-mail: mprud@chimp.univ.-bpclermont.fr
0968-0896/03/$ - see front matter # 2002 Elsevier Science Ltd. All rights reserved.
PII: S0968-0896(02)00532-1

680
C. Marminon et al. / Bioorg. Med. Chem. 11 (2003) 679–687
Figure 1.
vitro against a panel of murine and human tumor cells
lines are described and compared with those of rebec-
camycin 1, dechlorinated rebeccamycin 2,4 and the pre-
viously synthesized analogue A,3 which bears a methyl
group on the imide nitrogen.
phonyl group9 using benzenesulphonyl chloride in the
presence of sodium hydride. A second nucleophilic
attack of lithiated 7-azaindole on intermediate 4 in tol-
uene led to bis-azaindole 5.19 Several methods of N-
glycosylation of either bis-indolyl maleimides or indo-
locarbazoles have been described in the literature.20
Since the desired coupling product possesses a b-N-gly-
cosidic bond, the sugar part was introduced via a Mit-
sunobu reaction using 2,3,4,6-tetra-O-acetyl-a-d-
glucopyranose. This carbohydrate was prepared in three
steps from commercial 1,2,3,4,6-penta-O-acetyl-a-d-
glucopyranose (Scheme 2).21 The intermediate alkene,
with an a anomeric bond, was obtained by reaction of
tetraacetylglucopyranose with 3-buten-1-ol in the pre-
sence of SnCl4 as a catalyst. Ozonolysis led to the cor-
responding aldehyde, which was treated with potassium
carbonate to give the required sugar.
Results and Discussion
Chemistry
The synthesis of compound 10 is outlined in Scheme 1.
Compound 3 was obtained by coupling 7-azaindole
magnesium bromide with N-methyl-dibromomaleimide
in toluene solution. N-methyl-dibromomaleimide was
obtained by methylation of dibromomaleimide using
dimethylsulfate and potassium carbonate in acetone,
according to a classical procedure.17 Dibromomaleimide
was obtained in 67% yield by treatment of maleimide
with bromine in DMF at 55 ꢁC for 3 days. This method
is easier than the classical one from succinimide.18 The
indole nitrogen of 3 was protected with a benzenesul-
The Mitsunobu reaction with compound 5 gave b-N-
glycosylated compound 6 as the major product of the
reaction (65% yield). The b-configuration of 6 was
1
0
indicated in the H NMR spectrum by the H1 –H2
0
Scheme 1.

C. Marminon et al. / Bioorg. Med. Chem. 11 (2003) 679–687
681
Scheme 2.
coupling constant value (9 Hz), consistent with axial-
axial coupling.
hydrolysis of the acetates. Aminolysis yielded the aza-
rebeccamycin analogue 19.
The second azaindole nitrogen was deprotected using
tetrabutylammonium fluoride (TBAF) to yield 7. Dea-
cetylation of the hydroxyl groups of the sugar moiety
was performed with NH4OH in methanol leading to
compound 8 (Scheme 3), designed as an analogue in bis-
aza-indolylmaleimide series. b-N-Glycosylated com-
pound 7 was cyclized to aza-carbazole 9 by oxidative
irradiation in benzene in the presence of iodine. Hydro-
lysis of the acetate groups of the carbohydrate part led
to the required rebeccamycin analogue 10.
In vitro antiproliferative activities
The in vitro antiproliferative activities were tested
against three tumor cell lines, murine leukemia (L1210),
and two human solid tumors: colon carcinoma (HT29),
and non-small cell lung carcinoma A549. The results,
expressed as IC50 values, are reported in Table 1. Com-
pared with A and 10, compound 8, lacking an indolo-
carbazole framework, is inactive. The planar structure
of an indolocarbazole or diazaindolocarbazole seems
necessary for the cytotoxicity. The aza-analogue 19 with
the free imide NH exhibits the strongest cytotoxicity
toward L1210 cells, being slightly more potent than
rebeccamycin 1 and dechlorinated rebeccamycin 2 and
about ten times more efficient than the N-methyl analo-
gue 10. However, very different results were obtained on
the two human tumor cell lines : 10 is inactive on both
lines, while 19 is potent on HT29. These two com-
pounds thus appear to have some selectivity against
certain cell lines. To compare the cytotoxicity profile of
10 with those of 1, 2 and A, the antiproliferative activ-
ities against six other tumor cell lines were examined,
human leukemia (K-562) and five human solid tumors:
one ovarian carcinoma (IGROV1), one neuroblastoma
(SK-N-MC), one small-cell lung carcinoma (H69) and
An identical synthetic scheme was used to obtain N-
benzyloxymethyl-dibromomaleimide, the precursor of
compounds having a free NH imide function. The dif-
ferences were in the final deprotection steps (Scheme 4).
N-BOM-dibromomaleimide was prepared from dibro-
momaleimide using benzyloxymethyl chloride in the
presence of potassium carbonate in acetone. During the
coupling with the second aza-indole moiety using
LiHMDS, partial deprotection of the aza-indolic nitro-
gen was observed, leading to 14. The final deprotection
of compound 17 was performed in two steps. First,
hydrogenolysis with a catalytic amount of Pd/C in an
ethyl acetate/methanol mixture lead to 18 in low yield,
due to product adsorption on the catalyst and partial
Scheme 3.

682
C. Marminon et al. / Bioorg. Med. Chem. 11 (2003) 679–687
Scheme 4.
Table 1. In vitro antiproliferative activities (IC50 mM) against three
tumor cell lines: murine leukemia (L1210), human colon carcinoma
(HT29), human non-small cell lung carcinoma (A549)
accumulation in the G2+M phases. The most efficient
compound was aza-analogue 19, for which 66% of cells
were arrested in the G2+M phases at a drug concen-
tration of 0.25 mM (Table 3). Interestingly, the most
selective compound 10 is devoid of a significant effect on
L1210 cell cycle, suggesting a different mechanism of
action at the molecular level.
Compd
L1210
HT29
A549
1
2
A
8
10
19
0.14
0.11
0.67
66.1
0.58
0.067
0.3
2.5
0.86
>100
97
0.3
2.0
0.94
>100
>100
41.5
In conclusion, as a contribution to structure–activity
relationship studies in rebeccamycin analogues, the
synthesis of diazaindole analogues, with or without a
methyl group on the imide nitrogen, has been carried
out. The new compounds having azaindolocarbazole
frameworks have strong antiproliferative properties
against the murine L1210 tumor cell line. Compared
with rebeccamycin 1, dechlorinated rebeccamycin 2, and
N-methyl derivative A, compound 19 is more cytotoxic.
The cytotoxicity profiles of aza-analogues 10 and 19 are
quite different from those of the parent non-aza com-
pounds, which are non selective, and display similarly
cytotoxicity for all the cell lines. These data suggest
additional targets for the non-aza compounds. Conse-
quently, the aza-analogues might be less toxic in vivo
than rebeccamycin. Compared with 1 and 2, the effect
of 19 on the cell cycle of L1210 is about four times
greater for the accumulation of the cells in the G2+M
phases. By introducing nitrogen atoms in the indole
rings, our aim was to reinforce the interactions with the
active site of the target enzyme(s) or with DNA. The
first biological results seem to validate our hypothesis
0.57
two epidermoıd carcinomas (A431 and KB-3-1) (Table
2). While A is almost equally potent in all the cell lines
tested (IC50 range of 0.25–0.88 mM), 10 appears highly
cytotoxic for A431 cells, slightly less cytotoxic for SK-N-
MC, NCI-H69 and inactive in IGROV1 cells. Like com-
pound A, rebeccamycin 1 was non selective. This different
cytotoxicity profile suggests that the aza-analogues do not
share the same mechanism of action, or that additional
targets are affected by the non aza-analogues. The basis
for the selectivity of 10 is currently being investigated.
Effect on L1210 cell cycle
The effect on the L1210 cell cycle was investigated for
compounds 10 and 19 (i.e., those compounds which
exhibit strong antiproliferative activities against this
tumor cell line). As already observed for most rebecca-
mycin analogues tested so far, these compounds induced
Table 2. In vitro antiproliferative activities (IC50 mM) against six human tumor cell lines: leukemia (K-562) and five solid tumors: ovarian carci-
noma (IGROV1), neuroblastoma (SK-N-MC), small-cell lung carcinoma (H69) and two epidermoıd carcinomas (A431 and KB-3-1). Ne: not eval-
uated
Compd
IgROV1
SK-N-MC
A431
NCI-H69
K-562
KB-3-1
1
2
A
0.25
2.6
0.88
<0.1
<0.1
0.25
0.25
3.8
0.84
<0.1
<0.1
0.33
0.2
<0.1
ne
0.3
0.28
0.6

C. Marminon et al. / Bioorg. Med. Chem. 11 (2003) 679–687
683
Table 3. Effect on the cell cycle. Results are expressed as percentage
of cells recovered in the G2+M phases (concentration of the drug)
(4H, m), 8.32 (1H, d, J=4.6 Hz). 13C NMR (100 MHz,
CDCl3): 20.1, 20.6, 20.7, 20.9 (CH3CO), 22.0 (NCH3),
0
0
0
0
0
61.8 (C6 ), 68.1, 71.0, 73.2, 75.0, 80.5 (C1 , C2 , C3 , C4 ,
Compd
% of L1210 cells in the G2+M phase
0
C5 ), 117.9, 119.1, 128.3 (2C), 129.1, 129.2 (2C), 129.6,
(Control)
1
2
A
10
19
24%
129.9, 130.7, 134.5, 144.2, 145.6 (C tert arom), 105.8,
109.0, 118.0, 120.9, 125.1, 130.4, 137.9, 146.9, 147.8 (C
quat arom), 168.9, 169.5, 170.0, 170.7, 170.8ꢁ (2C) (C¼O).
69% (1 mM)
71% (1 mM)
77% (2.5 mM)
31% (5-20 mM)
66% (0.25 mM)
1-Methyl-3-[1-(2,3,4,6-tetra-O-acetyl-ꢀ-D-glucopyranosyl)-
1H-pyrrolo[2,3-b]pyridin-3-yl]-4-(1H-pyrrolo[2,3-b]pyridin-3-
yl)-1H-pyrrole-2,5-dione (7). To a solution of b-glycosy-
lated compound 6 (37 mg, 0.046 mmol) in THF (4 mL)
was added a solution of tetrabutylammonium fluoride
(1,1 M in THF) (0.125 mL, 0.137 mmol). The mixture
was stirred at room temperature for 2.5 h. Water was
added. After extraction with EtOAc, the organic phase
was dried over MgSO4, the solvent was removed and the
residue purified by flash chromatography (eluent cyclo-
hexane/EtOAc, 3:7) to give 7 (24 mg, 0.036 mmol, 78%
yield) as a yellow-orange solid. Mp 148–150 ꢁC; IR
which has now to be confirmed by DNA binding
experiments, topoisomerase I inhibition evaluation and
the search for new targets.
Experimental
Chemistry
1
(KBr), ꢀCO 1700, 1760 cmꢀ1, ꢀNH 3300–3600 cmꢀ1. H
IR spectra were recorded on a Perkin–Elmer 881 spec-
trometer (n in cmꢀ1). NMR spectra were performed on
a Bruker AC 400 (1H: 400 MHz, 13C: 100 MHz) (che-
mical shifts d in ppm, the following abbreviations are
used: singlet (s), broad singlet (br s), doublet (d), dou-
bled doublet (dd), triplet (t), pseudo-triplet (pt), multi-
plet (m), tertiary carbons (C tert), quaternary carbons
(C quat). Mass spectra (FAB+) were determined at
CESAMO (Talence, France) on a high resolution
Fisons Autospec-Q spectrometer. Chromatographic
purifications were performed by flash silicagel Geduran
SI 60 (Merck) 0.040-0.063 mm or Kieselgel 60 (Merck)
0.063-0.200 mm column chromatography. For purity
tests, TLC were performed on fluorescent silica gel
plates (60 F254 from Merck).
NMR (400 MHz, CDCl3): 1.70 (3H, s), 2.04 (3H, s),
2.09 (3H, s), 2.11 (3H, s), 3.21 (3H, s, NCH3), 4.07 (1H,
m), 4.18 (1H, dd, J1=12.5 Hz, J2=1.1 Hz), 4.31 (1H,
dd, J1=12.6 Hz, J2=4.6 Hz), 5.18 (1H, pt, J=9.4 Hz),
5.51 (1H, pt, J=9.5 Hz), 5.57 (1H, pt, J=9.4 Hz), 6.29
0
(1H, d, J=8.6 Hz, H1 ), 6.74 (1H, dd, J1=7.9 Hz,
J2=7.7 Hz), 6.83 (1H, dd, J1=7.9 Hz, J2=7.7 Hz), 7.20
(1H, d, J=7.9 Hz), 7.42 (1H, d, J=7.9 Hz), 8.05 (1H,
s), 8.06 (1H, s), 8.21 (2H, d, J=4.0 Hz), 11.08 (1H, s,
NH). 13C NMR (100 MHz, CDCl3): 20.2, 20.7, 20.8,
0
21.1 (CH3CO), 24.4 (NCH3), 61.8 (C6 ), 68.1, 70.9, 73.2,
0
0
0
0
0
74.9, 80.4 (C1 , C2 , C3 , C4 , C5 ), 116.7, 117.6, 128.7,
129.1, 130.4, 130.6, 143.5, 144.0 (C tert arom), 105.3,
106.6, 118.4, 118.9, 126.5, 128.3, 147.7, 148.6 (C quat
arom), 168.9, 169.5, 170.0, 170.8, 171.6, 171.8 (C¼O).
1-Methyl-3-[1-(2,3,4,6-tetra-O-acetyl-ꢀ-D-glucopyranosyl)-
1H-pyrrolo[2,3-b]pyridin-3-yl]-4-[1-(phenylsulphonyl)-1H-
pyrrolo[2,3-b]pyridin-3-yl]-1H-pyrrole-2,5-dione (6). To a
solution of 5 (250 mg, 0.518 mmol) in THF (20 mL),
were added 2,3,4,6-O-a-d-acetylglucopyranose (486 mg,
1.40 mmol) and triphenylphosphine (367 mg, 1.40
mmol). The mixture was cooled to ꢀ78 ꢁC, then DEAD
(220 mL, 1.40 mmol) was added dropwise. The mixture
was stirred at room temperature for 15 h. Water was
added. After extraction with EtOAc, the organic phase
was dried over MgSO4, the solvent was removed and the
residue purified by flash chromatography (eluent tolu-
ene/EtOAc, 30:25 then cyclohexane/EtOAc, 3:2) to give
b-glycosylated compound 6 (273 mg, 0.336 mmol, 65%
yield) as a yellow solid.
1-Methyl-3-[1-(ꢀ-D-glucopyranosyl)-1H-pyrrolo[2,3-b]pyri-
din-3-yl]-4-(1H-pyrrolo[2,3-b]pyridin-3-yl)-1H-pyrrole-2,5-
dione (8). To a solution of 7 (36 mg, 0.054 mmol) in
methanol (14 mL) was added 28% aqueous NH4OH (10
mL). The mixture was stirred for 26 h at room tem-
perature. After removal of the solvents, the residue was
purified by flash chromatography (eluent EtOAc/
methanol, 9:1) to give 8 (18 mg, 0.036 mmol, 67% yield)
as a red-orange solid. Mp 195-197 ꢁC; IR (KBr)
CO
1700, 1710 cmꢀ1, ꢀNH,OH 3200–3600 cmꢀ1. HRMS
(FAB+) (M+H)+ calcd for C25H24N5O7 506.1676,
found 506.1681. H NMR (400 MHz, DMSO-d6): 3.10
1
(3H, s, NCH3), 3.38 (1H, m), 3.49 (1H, d, J=7.7 Hz),
3.53 (2H, m), 3.77 (1H, m), 3.87 (1H, m), 4.95 (1H, t,
J=4.0 Hz, OH), 5.19 (1H, d, J=4.3 Hz, OH), 5.28 (1H,
d, J=3.4 Hz, OH), 5.33 (1H, d, J=4.6 Hz, OH), 5.89
Mp 116–118 ꢁC; IR (KBr), ꢀCO 1710, 1750 cmꢀ1. H
(1H, d, J=7.5 Hz, H1 ), 6.65 (1H, dd, J1=6.5 Hz,
1
0
NMR (400 MHz, CDCl3): 1.65 (3H, s), 2.04 (3H, s),
2.09 (3H, s), 2.11 (3H, s), 3.20 (3H, s, NCH3), 4.03–4.08
(1H, m), 4.19 (1H, dd, J1=1.7 Hz, J2=12.6 Hz), 4.32
(1H, dd, J1=4.6 Hz, J2=12.6 Hz), 5.29 (1H, m), 5.51
(2H, m), 6.26 (1H, m), 6.61 (1H, dd, J1=7.9 Hz, J2=4.7
Hz), 6.87 (1H, dd, J1=8.0 Hz, J2=4.8 Hz), 6.94 (1H,
dd, J1=7.9 Hz, J2=1.1 Hz), 7.34 (1H, dd, J1=7.9 Hz,
J2=3.6 Hz), 6.68 (1H, dd, J1=6.6 Hz, J2=3.6 Hz), 7,06
(1H, d, J=6,4 Hz); 7,27 (1H, d, J=6,4 Hz); 7,93 (1H,
s); 8,14 (1H, s); 8,16 (1H, d, J=3.6 Hz), 8.20 (1H, d,
J=3.6 Hz), 12.34 (1H, s, NH). 13C NMR (100 MHz,
0
DMSO-d6): 24.1 (NCH3), 62.8 (C6 ), 69.6, 72.0, 77.5,
0
0
0
0
0
80.1, 82.4 (C1 , C2 , C3 , C4 , C5 ), 116.2, 116.7, 129.1,
129.3, 129.9, 130.1, 143.2, 143.4 (C tert arom), 104.0,
104.5, 117.6, 118.0, 125.9, 128.3, 147.7, 148.3 (C quat
arom), 171.2 (2C) (C¼O).
J2=1.2 Hz), 7.50 (1H, t, J=7.7 Hz), 7.52 (1H, t, J=7.9
Hz), 7.63 (1H, t, J=7.6 Hz), 8.13 (1H, br s), 8.18–8.21

684
C. Marminon et al. / Bioorg. Med. Chem. 11 (2003) 679–687
6-Methyl-12-(2,3,4,6-tetra-O-acetyl-ꢀ-D-glucopyranosyl)-
12,13-dihydro-5H-pyrido[2,3-b]pyrido[30,20:4,5]pyrrolo[3,2-
g]pyrrolo[3,4-e]indole-5,7(6H)dione (9). A mixture of 7
(112 mg, 0.166 mmol) in benzene (150 mL) and iodine
(537 mg, 2.11 mmol) was irradiated for 1.5 h with a
medium pressure mercury lamp (400 W). The solvent
was removed and the residue dissolved in EtOAc (50
mL), washed with aqueous sodium thiosulfite then with
brine. The organic phase was dried over MgSO4, the
solvent was removed and the residue purified by flash
chromatography (eluent cyclohexane:EtOAc, 1:1) to
give 9 (85 mg, 0.127 mmol, 76% yield) as a pale-yellow
solid. Mp>300 ꢁC; IR (KBr) ꢀCO 1703, 1757 cmꢀ1, ꢀNH
3373 cmꢀ1. HRMS (FAB+) (M+H)+ calcd for
C33H30N5O11 672.1942, found 672.1938. 1H NMR
(400 MHz, CDCl3): 1.03 (3H, s), 1.90 (3H, s), 2.13 (3H,
s), 2.65 (3H, s), 3.21 (3H, s, NCH3), 4.44 (1H, d, J=9.9
Hz), 4.48 (1H, d, J=13.3 Hz), 4.87 (1H, d, J=12.0 Hz),
5.31 (1H, pt, J=9.3 Hz), 5.61 (1H, pt, J=9.4 Hz), 5.70
N-benzyloxymethyl-2,3-dibromomaleimide (756 mg, 2.01
mmol) in toluene (20 mL) was added dropwise. After
stirring for 20 min, dichloromethane (30 mL) was added
then the mixture was stirred for 65 h at 40ꢁC. Saturated
aqueous NH4Cl was added. After extraction with EtOAc,
the organic phase was dried over MgSO4, the solvent was
removed and the residue purified by flash chromato-
graphy (eluent cyclohexane/EtOAc, 3:2, then toluene/
EtOAc, 7:3) to give 11 (471 mg, 1.14 mmol, 57% yield) as
a yellow solid. Mp 168–170 ꢁC. IR (KBr) ꢀCO 1714, 1774
cmꢀ1, ꢀNH 3340–3500 cmꢀ1. 1H NMR (400 MHz, CDCl3)
4.70 (2H, s, CH2), 5.20 (2H, s, CH2), 7.23–7.40 (6H, m),
8.37 (1H, s), 8.48 (1H, d, J=3.8 Hz), 8.56 (1H, dd, J1=7.9
Hz, J2=0.9 Hz), 13.26 (1H, s, NH). 13C NMR (100MHz,
CDCl3) 67.7, 71.9 (CH2), 117.4, 127.7 (2C), 127.9, 128.5
(2C), 131.5, 132.6, 143.5 (C tert arom), 103.8, 115.7, 118.3,
137.1, 137.4, 149.2 (C quat arom), 166.1, 168.9 (C¼O).
1-[(Benzyloxy)methyl]-3-bromo-4-[1-(phenylsulphonyl)-1H-
pyrrolo[2,3-b]pyridin-3-yl]-1H-pyrrole-2,5-dione (12). To
a suspension of HNa (60% in mineral oil) (51 mg, 1.27
mmol) in THF (5 mmol) at 0 ꢁC was added dropwise a
solution of 11 (330 mg, 0.800 mmol) in THF (10 mL).
The mixture was stirred at 0 ꢁC for 1 h, then benzenesul-
phonyl chloride (125 mL, 0.98 mmol) was added drop-
wise. The mixture was stirred at room temperature for 4
h, then saturated aqueous NH4Cl was added. After
extraction with EtOAc, the organic phase was washed
with brine, dried over MgSO4, the solvent was removed
and the residue purified by flash chromatography (eluent
cyclohexane/EtOAc, 4:1) to give 12 (333 mg, 0.60 mmol,
75% yield) as a yellow solid. Mp 123–125 ꢁC. IR (KBr)
0
(1H, pt, J=9.6 Hz), 6,87 (1H, d, J=9.5 Hz, H1 ), 7,33
(1H, dd, J1=7.9 Hz, J2=4.8 Hz), 7.35 (1H, dd, J1=7.8
Hz, J2=4.9 Hz), 8.52 (1H, d, J=3.7 Hz), 8.56 (1H, d,
J=3.6 Hz,), 9.25 (2H, d, J=7.7 Hz), 10.19 (1H, s, NH).
13C NMR (100 MHz, CDCl3): 19.0, 20.5, 20.6, 21.1
0
(CH3CO), 23.8 (NCH3), 60.7 (C6 ), 67.2, 70.5, 72.9, 76.5,
0
0
0
0
0
82.1 (C1 , C2 , C3 , C4 , C5 ), 117.7, 118.3, 133.7, 134.0,
147.3, 148.1 (C tert arom), 114.8, 115.1, 116.7, 117.0,
120.0, 122.2, 127.0, 128.1, 152.1, 152.5 (C quat arom),
168.0, 169.2, 169.3, 169.4, 169,9, 171.8 (C¼O).
6-Methyl-12-(ꢀ-D-glucopyranosyl)-12,13-dihydro-5H-pyr-
ido[2,3-b]pyrido[30,20:4,5]pyrrolo[3,2-g]pyrrolo[3,4-e]indole-
5,7(6H)dione (10). To a solution of 9 (44 mg, 0.066
mmol) in methanol (40 mL) was added 28% aqueous
NH4OH (28 mL). The mixture was stirred for 26 h at
55 ꢁC. After removal of the solvents, water and EtOAc
were added to the residue. After filtration, the solid was
washed with EtOAc then methanol. Compound 10 (5
mg, 9.54.10ꢀ3 mmol, 14% yield) was obtained as a yel-
ꢀ
CO 1730, 1780 cmꢀ1. 1H NMR (400 MHz, CDCl3) 4.68
(2H, s, CH2), 5.18 (2H, s, CH2), 7.24–7.37 (6H, m), 7.55
(2H, t, J=7.5 Hz), 7.65 (1H, t, J=7.5 Hz), 8.24 (1H, dd,
J1=8.0 Hz, J2=1.3 Hz), 8.29 (1H, br s), 8.30 (1H, br s),
8.48 (1H, s), 8.51 (1H, dd, J1=4.7 Hz, J2=1.3 Hz). 13C
NMR (100 MHz, CDCl3) 67.9, 72.1 (CH2), 119.6, 127.6
(2C), 128.0, 128.5 (3C), 128.6 (2C), 129.3 (2C), 132.0,
134.8, 146.0 (C tert arom), 107.0, 119.8, 121.5, 135.4,
137.3, 137.5, 146.9 (C quat arom), 165.2, 167.9 (C¼O).
low solid: mp>300 ꢁC; IR (KBr) ꢀCO 1650, 1700 cmꢀ1
,
ꢀNH,OH 3200–3600 cmꢀ1. HRMS (FAB+) (M+H)+
calcd for C25H22N5O7 504.1519, found 504.1509. 1H
NMR (400 MHz, DMSO-d6): 3.23 (3H, s, NCH3), 3.62
(2H, m), 3.83 (1H, d, J=10.3 Hz), 3.91 (1H, d, J=9.5
Hz), 4.04 (2H, d, J=11.9 Hz), 5.01 (1H, d, J=4.1 Hz,
OH), 5.26 (1H, d, J=4.0 Hz, OH), 5.41 (1H, d, J=4.7
Hz, OH), 5;75 (1H, m, OH), 6.64 (1H, d, J=8.6 Hz,
1-[(Benzyloxy)methyl-3[1-(phenylsulphonyl)-1H-pyrrolo[2,3-
b]pyridin-3-yl]-4(1H-pyrrolo[2,3-b]pyridin-3-yl)-1H-pyrrole-
2,5-dione (13) and 1-[(benzyloxy)methyl-3(1H-pyr-
rolo[2,3-b]pyridin-3-yl)-4(1H-pyrrolo[2,3-b]pyridin-3-yl)-1H-
pyrrole-2,5-dione (14). To a solution of 7-azaindole (155
mg, 1.36 mmol) in toluene (10 mL) at ꢀ15 ꢁC was added
dropwise a solution of LiHMDS (1M in hexane) (1.52
mL, 1.52 mmol). The solution was stirred at ꢀ15 ꢁC for
1 h then a solution of 12 (300 mg, 0.543 mmol) in tolu-
ene (10 mL) was added dropwise at ꢀ20 ꢁC. The mix-
ture was stirred at room temperature for 24 h before
addition of saturated aqueous NH4Cl, then the pH was
adjusted to 7. After extraction with EtOAc, the organic
phase was washed with brine, dried over MgSO4, the
solvent was removed and the residue purified by flash
chromatography (eluent cyclohexane/EtOAc, 3:2) to
give 13 (99 mg, 0.168 mmol, 31% yield) and 14 (24 mg,
0.053 mmol, 10% yield) as orange solids.
0
H1 ), 7.54 (2H, m), 8.69 (2H,br s), 9.32 (1H, d, J=8.2
Hz), 9.35 (1H, d, J=8.2 Hz), 11.66 (1H, br s, NH). 13C
0
NMR (100 MHz, DMSO-d6): 23.8 (NCH3), 58.2 (C6 ),
0
0
0
0
0
67.9, 72.8, 76.8, 79.1, 83.0 (C1 , C2 , C3 , C4 , C5 ), 117.3,
117.6, 132.5, 132.8, 147.5, 148.4 (C tert arom), 114.0
(2C), 115.6, 116.1, 119.9, 121.0, 127.2, 128.3, 152.3,
152.7 (C quat arom), 169.4 (2C) (C¼O).
1-[(Benzyloxy)methyl]-3-bromo-4-(1H-pyrrolo[2,3-b]pyri-
din-3-yl)-1H-pyrrole-2,5-dione (11). A solution of ethyl-
magnesium bromide was prepared from Mg (146 mg,
6.00 mmol) and C2H5Br (452 mL, 6.00 mmol) in THF
(2.5 mL). The mixture was stirred for 1 h at room tem-
perature then 7-azaindole (708 mg, 6.00 mmol) in tolu-
ene (20 mL) was added dropwise. The mixture was
stirred at room temperature for 1.5 h then a solution of
13: mp 115–117 ꢁC; IR (KBr) ꢀCO 1707, 1730 cmꢀ1, ꢀNH
.
3300–3400 cmꢀ1 1H NMR (400 MHz, CDCl3) 4.73

C. Marminon et al. / Bioorg. Med. Chem. 11 (2003) 679–687
685
(2H, s, CH2), 5.24 (2H, s, CH2), 6.61 (1H, dd, J1=8.1
Hz, J2=4.8 Hz), 6.86 (1H, dd, J1=8.0 Hz, J2=4.7 Hz),
7.03 (1H, dd, J1=8.0 Hz, J2=1.2 Hz), 7.19–7.31 (4H,
m), 7.39 (2H, dd, J1=8.4 Hz, J2=1.3 Hz), 7.53 (2H, t,
J=7.6 Hz), 7.64 (1H, dt, J1=7.5 Hz, J2=1.2 Hz), 8.17
(2H, br s), 8.21–8.25 (3H, m), 8.36 (1H, dd, J1=4.7 Hz,
J2=1.5 Hz), 12.93 (1H, s, NH). 13C NMR (100 MHz,
CDCl3) 67.5, 71.9 (CH2), 116.8, 119.1, 127.6, 127.8,
128.3 (2C), 128.4 (2C), 128.6, 128.8, 129.2, 129.8, 130.3,
130.6, 131.2, 134.5, 143.3, 145.7 (C tert arom), 104.3,
108.9, 118.0, 120.7, 123.9, 131.4, 137.7, 137.8, 146.8,
148.9 (C quat arom), 170.4, 170.7 (C¼O).
0.168 mmol) in THF (6 mL) was added a solution of
tetrabutylammonium fluoride (1.1 M in THF) (457 mL,
0.503 mmol). The mixture was stirred for 3 h at room
temperature. Water was added. After extraction with
EtOAc, the organic phase was dried over MgSO4, the
solvent was removed and the residue purified by flash
chromatography (eluent cyclohexane/EtOAc, 2:3) to
give 16 (100 mg, 0.128 mmol, 76% yield) as an orange
solid. Mp 127–129 ꢁC; IR (KBr) ꢀCO 1710, 1750 cmꢀ1
,
ꢀNH 3300–3500 cmꢀ1. HRMS (FAB+) (M+H)+ calcd
C40H38N5O12 780.2517, found 780.2518. 1H NMR
(400 MHz, CDCl3): 1.71 (3H, s), 2.03 (3H, s), 2.07 (3H,
s), 2.09 (3H, s), 4.09 (1H, m), 4.18 (1H, d, J=12.3 Hz),
4.30 (1H, dd, J1=12,6 Hz, J2=4,6 Hz); 4,71 (2H, s,
CH2); 5,22 (2H, s, CH2); 5,31 (1H, t, J=9,6 Hz), 5.53
(1H, pt, J=9.1 Hz), 5.59 (1H, t, J=9.4 Hz), 6.31 (1H, d,
14: mp 239–241 ꢁC. IR (KBr) ꢀCO 1710, 1760 cmꢀ1, ꢀNH
1
3300–3600 cmꢀ1. H NMR (400 MHz, DMSO-d6) 4.67
(2H, s, CH2), 5.12 (2H, s, CH2), 6.77 (2H, dd, J1=7.6
Hz, J2=4.7 Hz), 7.10 (2H, d, J=7.8 Hz), 7.27–7.39 (5H,
m), 7.97 (2H, s), 8.16 (2H, d, J=3.8 Hz), 12.39 (2H, s,
NH). 13C NMR (100 MHz, DMSO-d6) 67.1, 70.5 (CH2),
115.9 (2C), 127.4 (2C), 127.5 (2C), 128.2 (2C), 128.9 (2C),
129.9, 143.4 (2C) (C tert arom), 103.8 (2C), 117.4 (2C),
127.1, 137.9 (2C), 148.4 (2C) (C quat arom), 170.9 (2C)
(C¼O).
0
J=8.8 Hz, H1 ), 6.69 (1H, t, 4.3 Hz), 6.72 (1H, t, 4.3
Hz), 7.15 (2H, t, J=7.5 Hz), 7.21 (1H, d, J=7.1 Hz),
7.28 (2H, t, J=7.3 Hz), 7.38 (2H, d, J=7.4 Hz), 8.07
(1H, s), 8.13 (1H, s), 8.20 (2H, dd, J1=9.4 Hz, J2=4.3
Hz), 12.78 (1H, s, NH). 13C NMR (100 MHz, CDCl3):
0
20.1, 20.6, 20.7, 21.0 (CH3CO), 61.8 (C6 ), 67.3, 71.6
0
0
0
0
0
(CH2), 68.1, 70.9, 73.1, 74.8, 80.3 (C1 , C2 , C3 , C4 , C5 ),
116.4, 117.5, 127.6 (3C), 127.7 (2C), 128.3 (2C), 130.3,
130.5, 142.9, 143.8 (C tert arom), 104.6, 106.3, 118.5,
118.8, 126.0, 128.6, 137.6, 147.5, 148.7 (C quat arom),
168.8, 169.5, 170.0, 170.6, 170.9, 171.1 (C¼O).
1-[(Benzyloxy)methyl]-3-[1-(2,3,4,6-tetra-O-acetyl-ꢀ-D-glu-
copyranosyl)-1H-pyrrolo[2,3-b]pyridin-3-yl]-4-[1-(phenyl-
sulphonyl)-1H-pyrrolo[2,3-b]pyridin-3-yl]-1H-pyrrole-2,5-
dione (15). To a solution of 13 (356 mg, 0.604 mmol) in
THF (30 mL) were added 2,3,4,6-O-acetylglucopyr-
anose (372 mg, 1.09 mmol) and triphenylphosphine (285
mg, 1.09 mmol). The mixture was cooled to ꢀ78 ꢁC then
DEAD (174 mL, 1.09 mmol) was added dropwise. The
mixture was stirred at room temperature for 15 h.
Water was added. After extraction with EtOAc, the
organic phase was dried over MgSO4, the solvent was
removed and the residue purified by flash chromato-
graphy (eluent cyclohexane/EtOAc, 1:1, then toluene/
EtOAc, 3:2) to give b-glycosylated compound 15 (377
mg, 0.410 mmol, 68% yield) as a yellow solid. Mp 108-
110 ꢁC. IR (KBr) ꢀCO 1720, 1760 cmꢀ1. HRMS (FAB+)
(M+H)+ calcd C46H42N5O14S 920.2449, found
920.2443. 1H NMR (400 MHz, CDCl3): 1.62 (3H, s,
CH3CO), 1.99 (3H, s, CH3CO), 2.03 (3H, s, CH3CO),
2.04 (3H, s, CH3CO), 4.05 (1H, m), 4.15 (1H, d, J=11,2
Hz), 4.28 (1H, dd, J1=12.6 Hz, J2=4.6 Hz), 4.65 (2H,
s, CH2), 5.17 (2H, s, CH2), 5.27 (1H, m), 5.45–5.52 (2H,
m), 6.24 (1H, m), 6.51 (1H, m), 6.78–6.84 (2H, m), 7.13
(1H, t, J=7.2 Hz), 7.19–7.25 (3H, m), 7.31 (2H, d,
J=7.4 Hz), 7.46 (2H, t, J=7.9 Hz), 7.57 (1H, t, J=7.4
Hz), 8.06 (1H, br s), 8.11–8.14 (3H, m), 8.13 (1H, s),
8.26 (1H, d, J=4.4 Hz). 13C NMR (100 MHz, CDCl3):
6-[(Benzyloxy)methyl]-12-(2,3,4,6-tetra-O-acetyl-ꢀ-
D-glucopyranosyl)-12,13-dihydro-5H-pyrido[2,3-b]pyri-
do[30,20:4,5]pyrrolo[3,2-g]-pyrrolo[3,4-e]indole-5,7(6H)-
dione (17). A solution of 16 (96 mg, 0.123 mmol) and
iodine (376 mg, 1,48 mmol) in benzene (150 mL) was
irradiated for 1.5 h with a medium pressure mercury
lamp (400 W). The solvent was removed and the
residue dissolved in EtOAc (50 mL), washed with
aqueous sodium thiosulfite then with brine. The
organic phase was dried over MgSO4, the solvent was
removed and the residue purified by flash chromato-
graphy (eluent cyclohexane/EtOAc, 2:3) to give 17 (73
mg, 0.094 mmol, 76% yield) as a pale-yellow solid. Mp
194–196 ꢁC; IR (KBr) ꢀCO 1690, 1730 cmꢀ1, ꢀNH 3300–
3400 cmꢀ1
.
HRMS (FAB+) (M+H)+ calcd
C40H36N5O12 778.2360, found 778.2388. 1H NMR
(400 MHz, CDCl3): 1.08 (3H, s), 1.93 (3H, s), 2.14 (3H,
s), 2.65 (3H, s), 4.39 (1H, dd, J1=10.2 Hz, J2=1.9 Hz),
4.44 (1H, dd, J1=12.8 Hz, J2=1.7 Hz), 4.79 (2H, AB
system, J=12.2 Hz, Áꢀ=12.1 Hz), 4.85 (1H, dd,
J1=13.1 Hz, J2=2.0 Hz), 5,30 (2H, AB system, J=11.0
Hz, Áꢀ=8.9 Hz), 5.36 (1H, t, J=9.4 Hz), 5.60 (1H, t,
J=9.4 Hz), 5.71 (1H, t, J=9.6 Hz), 6.93 (1H, d, J=9.5
0
19.9, 20.3 (2C), 20.4 (CH3CO), 61.6 (C6 ), 67.3, 71.6
0
Hz, H1 ), 7.25 (1H, m), 7.32–7.42 (4H, m), 7.48 (2H, dd,
0
0
0
0
0
(CH2), 67.9, 71.0, 72.7, 74.7, 80.3 (C1 , C2 , C3 , C4 , C5 ),
117.6, 118.9, 128.0 (2C), 128.2 (2C), 128.6 (2C), 129.0
(2C), 129.6 (2C), 129.7, 130.2, 131.8, 134.3, 144.0, 145.4
(C tert arom), 105.3, 108.5, 117.7, 120.5, 125.0, 130.6,
137.5 (2C), 146.6, 147.5 (C quat arom), 168.6, 169.3,
169.7, 169.9, 170.0, 170.4 (C¼O).
J1=7.1 Hz, J2=1.3 Hz), 8.54 (1H, dd, J1=4.8 Hz,
J2=1.6 Hz), 8.62 (1H, dd, J1=4.6 Hz, J2=1.5 Hz), 9.32
(1H, dd, J1=7.9 Hz, J2=1.8 Hz), 9.34 (1H, dd, J1=7.9
Hz, J2=1.5 Hz), 10.30 (1H, s, NH). 13C NMR
(100 MHz, CDCl3): 19.1, 20.5, 20.6, 21.1 (CH3CO), 60.6
0
(C6 ), 66.9, 71.7 (CH2), 67.2, 70.6, 72.9, 76.5, 82.1 (C1 ,
0
0
0
0
0
C2 , C3 , C4 , C5 ), 117.8, 118.4, 127.9 (3C), 128.0 (2C),
133.8, 134.2, 147.4, 148.3 (C tert arom), 114.8, 115.1,
116.9, 117.2, 119.7, 121.9, 127.4, 128.4, 137.6, 152.0,
152.5 (C quat arom), 168.0, 168.9, 169.3, 169.9, 171.8
(2C) (C¼O).
1-[(Benzyloxy)methyl]-3-[1-(2,3,4,6-tetra-O-acetyl-ꢀ-D-glu-
copyranosyl)-1H-pyrrolo[2,3-b]pyridin-3-yl]-4-(1H-
pyrrolo[2,3-b]pyridin-3-yl)-1H-pyrrole-2,5-dione
(16).
To a solution of b-glycosylated compound 15 (154 mg,

686
C. Marminon et al. / Bioorg. Med. Chem. 11 (2003) 679–687
6-(Hydroxy)methyl-12-(2,3,4,6-tetra-O-acetyl-ꢀ-D-gluco-
pyranosyl)-12,13-dihydro-5H-pyrido[2,3-b]pyrido[30,20:4,5]
pyrrolo[3,2-g]-pyrrolo[3,4-e]indole-5,7(6H)-dione (18). A
mixture of 17 (70 mg, 0.090 mmol) and 10% Pd/C (84
mg) in methanol (4.5 mL) and EtOAc (1.5 mL) was
hydrogenated for 24 h (1 bar). After 24 h, 10% Pd/C (42
mg) was added and the mixture was hydrogenated for
24 h (1 bar). After filtration over Celite, the solid was
washed with methanol and CHCl3. After removal of the
solvents, purification of the residue by flash chromato-
graphy (cyclohexane/EtOAc, 3:2), gave the starting
product 17 (19 mg, 0.024 mmol, 27%), compound 18
(cyclohexane/EtOAc, 1:1) (9 mg, 0.013 mmol, 15%
yield) as a pale-yellow solid and a mixture of com-
pounds partially deacetylated (41 mg) (EtOAc/metha-
nol, 9:1).
(L1210), one human leukemia (K-562) and seven human
solid tumors: one ovarian carcinoma (IGROV1), one
neuroblastoma (SK-N-MC), one colon carcinoma
(HT29), one non-small cell lung carcinoma (A549), one
small-cell lung carcinoma (H69) and two epidermoıd
carcinomas (A431 and KB-3-1). They were cultivated in
RPMI 1640 medium (Life Science technologies, Cergy-
Pontoise, France) supplemented with 10% fetal calf
serum, 2 mM l-glutamine, 100 units/mL penicillin, 100
mg/mL streptomycin, and 10 mM HEPES buffer
(pH=7.4). Cytotoxicity was measured by the micro-
culture tetrazolium assay as described.22 Cells were
continuously exposed to graded concentrations of the
compounds for four doubling times, then 15 mL of 5
mg/mL 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetra-
zolium bromide were added to each well and the plates
were incubated for 4 h at 37 ꢁC. The medium was then
aspirated and the formazan solubilized by 100 mL of
DMSO. Results are expressed as IC50, concentration
which reduced by 50% the optical density of treated
cells with respect to untreated controls.
18: mp>300 ꢁC; IR (KBr) ꢀCO 1710, 1760 cmꢀ1
NH=3300–3600 cmꢀ1. HRMS (FAB+) (M+H)+
,
ꢀ
calcd C33H30N5O12 688.1891, found 688.1898. 1H NMR
(400 MHz, CDCl3: 0.85 (3H, s), 1.83 (3H, s), 2.12 (3H,
s), 2.69 (3H, s), 4.50 (1H, d, J=9.8 Hz), 4.81–4.95 (3H,
m, 2H+OH), 5.04 (1H, d, J=12.6 Hz), 5.23 (1H, d,
J=10.8 Hz), 5.32 (1H, dd, J1=11.5 Hz, J2=4.5 Hz),
5.49 (1H, t, J=9.3 Hz), 5.57 (1H, t, J=9.6 Hz), 6.72
Cell cycle analysis. For the cell cycle analysis, L1210
cells (2.5ꢂ105 cells/mL) were incubated for 21 h with
various concentrations of the compounds, then fixed by
70% ethanol (v/v), washed and incubated in PBS con-
taining 100 mg/mL RNAse and 25 mg/mL propidium
iodide for 30 min at 20 ꢁC. For each sample, 104 cells
were analyzed on a XL/MCL flow cytometer (Beckman
Coulter). The fluorescence of propidium iodide was
collected through a 615 nm long-pass filter. Results are
expressed as the highest% of cells accumulated in the
G2+M phases of the cell cycle by a non-toxic (no cell
lysis) concentration.
0
(1H, d, J=9.5 Hz, H1 ), 7.26 (1H, dd, J1=7.6 Hz,
J2=4.9 Hz), 7.48 (1H, dd, J1=7.8 Hz, J2=4.8 Hz), 8.30
(1H, d, J=4.4 Hz), 8.71 (1H, d, J=4.7 Hz), 8.82 (1H, d,
J=7.8 Hz), 9.18 (1H, d, J=7.8 Hz), 9.85 (1H, s, NH).
13C NMR (100 MHz, CDCl3): 18.8, 20.5, 20.6, 21.4
0
(CH3CO), 60.7, 60.9 (CH2OH, C6 ), 67.0, 70.2, 72.9,
0
0
0
0
0
76.5, 82.6 (C1 , C2 , C3 , C4 , C5 ), 117.8, 118.5, 132.9,
135.1, 147.9, 148.2 (C tert arom), 113.8, 115.4, 116.5,
118.1, 121.9, 126.3, 127.7, 128.6, 151.6, 151.7 (C quat
arom), 167.6, 167.7, 168.0, 169.3, 169.9, 172.2 (C¼O).
12-(ꢀ-D-Glucopyranosyl)-12,13-dihydro-5H-pyrido[2,3-
b]pyrido[30,20:4,5]pyrrolo[3,2-g]-pyrrolo[3,4-e]indole-
5,7(6H)-dione (19). A solution of 18 (36 mg, 0.053
mmol) and 28% aqueous NH4OH (13 mL) in methanol
(15 mL) was stirred for 21 h at 40 ꢁC. The solvents were
removed, water and EtOAc were added to the residue.
After filtration, the solid was washed with EtOAc then
methanol. Compound 19 was obtained (8 mg, 0.016
mmol, 30% yield) as a yellow-brown solid. Mp>300 ꢁC;
IR (KBr) ꢀCO 1710, 1760 cmꢀ1, ꢀNH,OH 3200–3600
cmꢀ1. HRMS (FAB+) (M+H)+ calcd C24H20N5O7
490.1363, found 490.1369. 1H NMR (400 MHz, DMSO-
d6): 3.54–3.68 (2H, m), 3.82 (1H, d, J=10.3 Hz), 3.91
(1H, d, J=9.2 Hz), 4.03 (2H, d, J=9.2 Hz), 5.01 (1H, br
s, OH), 5.26 (1H, br s, OH), 5.41 (1H, d, J=4.6 Hz,
References and Notes
1. Nettleton, D. E.; Doyle, T. W.; Krishnan, B.; Matsumoto,
G. K.; Clardy, J. Tetrahedron Lett. 1985, 26, 4011.
2. Bush, J. A.; Long, B. H.; Catino, J. J.; Bradner, W. T.;
Tomita, K. J. Antibiot. 1987, 40, 668.
3. Anizon, F.; Belin, L.; Moreau, P.; Sancelme, M.; Voldoire,
A.; Prudhomme, M.; Ollier, M.; Severe, D.; Riou, J-F.; Bailly,
C.; Fabbro, D.; Meyer, T. J. Med. Chem. 1997, 40, 3456.
4. Moreau, P.; Anizon, F; Sancelme, M.; Prudhomme, M.;
Bailly, C.; Carrasco, C.; Ollier, M.; Severe, D.; Riou, J.-F.;
Fabbro, D.; Meyer, T.; Aubertin, A.-M. J. Med. Chem. 1998,
41, 1631.
5. Kaneko, T.; Wong, H.; Utzig, J.; Schurig, J.; Doyle, T. W.
J. Antibiot. 1990, 43, 125.
6. Prudhomme, M. Curr. Med. Chem. 2000, 7, 1189.
7. Voldoire, A.; Sancelme, M.; Prudhomme, M.; Colson, P.;
Houssier, C.; Bailly, C.; Leonce, S.; Lambel, S. Bioorg. Med.
Chem. 2001, 9, 357.
0
OH), 5.73 (1H, br s, OH), 6.65 (1H, d, J=8.6 Hz, H1 ),
7.57 (2H, m), 8.69 (2H, m), 9.34 (1H, d, J=8.1 Hz), 9.37
(1H, d, J=7.9 Hz), 11.26 (1H, s, NH), 11.66 (1H, s,
13
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NH). C NMR (100 MHz, DMSO-d6): 58.2 (C6 ), 67.9,
0
0
0
0
0
72.8, 76.8, 79.1, 83.0 (C1 , C2 , C3 , C4 , C5 ), 117.2, 117.6,
132.6, 132.9, 147.5, 148.3 (C tert arom), 114.0 (2C),
115.5, 115.7, 120.9, 122.0, 128.1, 129.8, 153.1, 153.3 (C
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