Tetrahydropyrrolo[3,2-c]azepin-4-ones as a new class of cytotoxic compounds

Article abstract of DOI:10.1016/j.bmc.2006.02.012

Pyrroloazepinones 8a-j and 9a-j were designed by structural modification of lead compound 3. These compounds were tested on five tumor cell lines to determine the role of the azeto ring and the 2-methyl substituent in the cytotoxicity of compound 3. Our r

Full text of DOI:10.1016/j.bmc.2006.02.012

Bioorganic & Medicinal Chemistry 14 (2006) 4007–4016
Tetrahydropyrrolo[3,2-c]azepin-4-ones as a new class
of cytotoxic compounds
a,
b
a
´
*
´
´
Roberto Martınez, J. Gustavo Avila, Ma. Teresa Ramırez,
a
a
´
´
´
Araceli Perez and Angeles Martınez
aInstituto de Quı´mica, Universidad Nacional Auto´noma de Me´xico, Circuito Exterior, Ciudad Universitaria,
04510 Coyoaca´n, Me´xico, DF, Mexico
bFacultad de Quı´mica, Universidad Nacional Auto´noma de Me´xico, Circuito Exterior, Ciudad Universitaria,
04510 Coyoaca´n, Me´xico, DF, Mexico
Received 7 December 2005; revised 2 February 2006; accepted 6 February 2006
Available online 28 February 2006
Abstract—Pyrroloazepinones 8a–j and 9a–j were designed by structural modification of lead compound 3. These compounds were
tested on five tumor cell lines to determine the role of the azeto ring and the 2-methyl substituent in the cytotoxicity of compound 3.
Our results show that compounds 8a–j (R1 = CH3) have dramatically reduced cytotoxicity, resulting from the loss of the azeto moi-
ety of lead compound 3. By contrast, azepinones 9a–j (R1 = 4-nitrophenyl) inhibited the proliferation of almost all cancer cell lines
tested even though they lack the azeto ring. Preliminary SAR studies with these compounds revealed the importance of halogens at
the para- or meta-position of the 1-phenyl moiety. Additionally, derivatives 9a (R2 = H), 9e (R2 = 4-F), and 9g (R2 = 4-OMe) were
selectively cytotoxic to U-251 cells. However, none of the pyrroloazepinones inhibited the enzymatic activity of CDK1/cyclin B,
CDK5/p25, and GSK-3.
ꢀ 2006 Elsevier Ltd. All rights reserved.
1. Introduction
electrostatic interaction between the acidic Asp145 and
the basic guanidinium ring of the inhibitor (Fig. 2).6
Within the paullone family, kenpaullone 1a and alster-
paullone 1b are two outstanding examples in terms of
anticancer activity.7 The paullones and HD have been
intensively investigated as inhibitors of cellular
proliferation.8
The cyclin-dependent kinases (CDKs) are a family of
enzymes that drive the cell cycle.1 Inhibitors of CDK
have been shown to disrupt the cell cycle and to have
potential value in the treatment of cancer.2 Some of
the most potent CDK inhibitors include 7,12-dihydroin-
dolo[3,2-d]benzazepin-6(5H)-ones 1 (paullones)3 and
(Z)-4-(2-amino-4-oxo-1H-imidazol-5(4H)-ylidene)-2-
bromo-4,5,6,7-tetrahydropyrrolo[2,3-c]azepin-8 (1H)-
O
OC6H5
SCH3
H2N
N
O
O
HN
4
A
HN
one 2 (hymenialdisine; HD). Kenpaullone and HD
N
C
N
act by competitive inhibition of ATP binding, and
molecular modeling shows that kenpaullone can bind
to the ATP-binding site of CDK2 with residue contacts
similar to those observed in the crystal structures of
other CDK2-inhibitor complexes (Fig. 1).5 HD, by con-
trast, belongs to a new class of small molecules that act
as tight binding inhibitors of CDK due to the formation
of strong, specific hydrogen bonds and a short-range
B
X
HN
NH
Br
N
H
1
O
1a X= Br
1b X= NO2
3
2
I
In this light, we are currently engaged in a program
aimed at synthesizing original heterocyclic compounds
that inhibit the growth of cancer cells.9 One of these
compounds is azetopyrroloazepinone 3, which shows
in vitro cytotoxic activity against PC-3 (prostate) and
U251 (central nervous system) cancer cell lines.10 This
molecule is composed of three units: an azeto ring (A),
an azepine ring (B), and a five-membered heterocyclic
Keywords: Pyrroloazepinones; Cytotoxic activity; CDK1/cyclin B;
CDK5/p25; GSK-3 activity.
*
Corresponding author. Tel.: +52 56 22 44 41; fax: +52 16 22 03;
e-mail: robmar@servidor.unam.mx
0968-0896/$ - see front matter ꢀ 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2006.02.012

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R. Martınez et al. / Bioorg. Med. Chem. 14 (2006) 4007–4016
4008
ring (C). Because structural modification is an effective
Lys 89
Asp 86
approach for understanding the mechanism of drug ac-
tion and for designing better drugs,11 an exploration of
structural changes of compound 3 and cytotoxic activity
evaluation of generated compounds should help deter-
mine the mechanism of its antiproliferative activity. As
a first approach, we substituted the pyrrolo ring of 3
with a thiophene (series 4), a furan (series 5), or a ben-
zene ring (series 6) by using bioisosteric modification
(Fig. 3). The cytotoxic activities of the new compounds
corresponded to their C ring aromaticities.12 We recent-
ly explored the role of the substituents attached to the
3-phenyl ring of compound 3 (compound series 7) in
the inhibition of cancer cell growth (Fig. 3).13 The re-
sults indicated an apparent relationship between the
cytotoxic activity of the 3-halogen derivatives and both
the electronegativity and size of the halogen.
O
Leu 134
CD2
O
CB
Ile 10
CE-NH3
H
O
O
N
N
H
Gin 131
Leu 83
NH
O
H
Ala 31
Br
Ala 144
CG1
G2C
Val 18
Phe 80
Figure 1. Possible interactions between kenpaullone and CDK2.5
We removed the azeto ring from compound 3 (generat-
ing compound series 8) to determine its role in the
cytotoxic activity. These compounds have part of the
pharmacophore found in the paullones and HD. In other
CDK2-inhibitor complexes, the 2-bromine substituent of
HD is an aromatic group, and alsterpaullone 1b contains
a 9-nitro group. Because both of these retain potent
CDK inhibitory and cytotoxicity activity, we speculated
that similarly substituted 2-nitrophenylipyrroloazepi-
none derivatives (compound series 9) would exhibit
potent antiproliferative activity.
Asp145
O
O
O
N
H
N
H
O
H
N
H2O
N
H
O
OH2
N
H
O
N
H
N
Gln131
Br
Here we report the synthesis of pyrrolo[3,2-a]azepinone
derivatives 8a–j and pyrrolo[3,2-a]azepinone com-
pounds 9a–j. Both series lack the azeto moiety found
in 3. In addition, in 9a–j, the 2-methyl substituent is re-
placed by a 2-(p-nitrophenyl) group (Chart 1). We also
report on the cytotoxic activity and the CDK1/cyclin
B, CDK5/p25, and GSK-3 inhibitory activity of these
compounds.
N
H
H
O
HN
O
Glu81
O
H
N
Leu83
Figure 2. Possible interactions between Hymenialdisine and CDK2.6
OC6H5
SCH3
O
N
S
4
OC6H5
SCH3
OC6H5
SCH3
OC6H5
SCH3
O
O
bioisosteric
substitution of C-ring
N
O
role of
R-substituent
N
N
C
N
O
N
5
R
3
7
I
OC6H5
SCH3
O
N
OMe
6
Figure 3. Exploration of the azetopyrroloazepinone 3 pharmacophore.

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R. Martınez et al. / Bioorg. Med. Chem. 14 (2006) 4007–4016
4009
none (R1 = CH3) or 2-bromo-4-nitroacetophenone
(R1 = 4-NO2-C6H4) to provide tricarbonyl compounds
10 and 11 in good yields. The second step involves ring
closure in compounds 10 and 11 to indol-4-ones 12a-j
and 13a-j under Paal–Knor conditions using different
substituted anilines as amines. In the third step, quanti-
tative oximation of compounds 12a–j and 13a–j was
achieved with hydroxylamine hydrochloride in ethanol
and in the presence of sodium carbonate to give oximes
14a–j and 15a–j. Finally, regioselective Beckmann rear-
rangement of the syn- and anti-oximes 14a–j and 15a–j
gave azepinones 8a–j and 9a–j as the sole products. It
is commonly assumed the group that migrates in the
Beckmann rearrangement is the one anti to the hydroxyl
and here should be formed both azepinones 9a–j and
16a–j (Scheme 2). One possible explanation to observe
regioselectivity is that anti oximes undergo isomeriza-
tion to syn oximes under the reaction conditions before
migration takes place. To test this assertion, an 1H
NMR experiment with the syn/anti oxime mixture 14b
in the presence of polyphosphoric acid at 80 ꢁC was car-
ried out. As can be seen in Figure 4 anti-oxime isomer-
izes to syn-oxime instead of furnishing azepinone 10b.
OC6H5
SCH3
O
A
N
C
N
B
3
I
-azeto ring
2-CH3 x 2-(4-NO2C6H4)
-azeto ring
9 R1= 4-NO2C6H4
9a R2= H
9b R2= 4-I
8 R1= CH3
8a R2= H
8b R2= 4-I
8c R2= 4-Br
8d R2= 4-Cl
8e R2= 4-F
O
O
9c R2= 4-Br
9d R2= 4-Cl
9e R2= 4-F
9f R2= 4-CH3
9g R2= 4-OCH3
9h R2= 4-NO2
9i R2= 3-Br
HN
HN
R1
R2
R1
R2
N
8f R2= 4-CH3
N
8g R2= 4-OCH3
8h R2= 4-NO2
8i R2= 3-Br
9j R2= 3-Cl
8j R2= 3-Cl
Chart 1. Structural modification of lead compound 3.
2. Chemistry
The preparation of compounds 8a-j and 9a-j involves a
four-step procedure starting from commercially avail-
able 5,5-dimethyl-1,3-cyclohexanodione (dimedone) as
we have described previously (Scheme 1).14 The first step
involves alkylation of dimedone with 1-chloro-2-propa-
O
O
O
R1
a
b
R1
O
N
O
O
10 R1= CH3
11 R1= 4-NO2C6H4
R2
12 R1= CH3
13 R1= 4-NO2C6H4
NOH
O
HN
c
R1
d
R1
R2
N
N
R2
8a-j R1= CH3
9a-j R1= 4-NO2C6H4
14 R1= CH3
15 R1= 4-NO2C6H4
Scheme 1. Synthesis of tetrahydropyrroloazepinones 8a–j and 9a–j.
Reagents and conditions: (a) K2CO3, R1COCH2Cl, CHCl3, rt, 48 h;
(b) R2C6H4NH2, CH3CO2H, reflux, 12 h; (c) NH2OH.HCl, NaOH aq,
EtOH, reflux, 2 h; (d) PPA, 80 ꢁC, 3 h.
Figure 4. 1H NMR experiments of Beckmann rearrangement reaction
of syn/anti oximes 16b.
OH
HO
N
N
H
H
O
H
O
N
H
HN
H
H
X
N
N
N
N
I
I
I
I
16b
8b
anti-oxime
syn-oxime
Scheme 2. Proposed reaction mechanism for the Beckmann rearrangement of syn/anti oximes 14b.

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R. Martınez et al. / Bioorg. Med. Chem. 14 (2006) 4007–4016
4010
3. Biological activity
(IC50 = 6.3 lM) was 10-fold more cytotoxic than lead
compound 3 (IC50 = 87 lM) against PC-3 prostate can-
cer cells. Also, compounds 9b, 9c, 9d, 9h, and 9i were
more active than 3 against this cell line (Table 3). The
most active compounds against the proliferation of
K-562 cells were 9d (R2 = 4-Cl; IC50 = 15 lM), 9i
(R2 = 3-Br; IC50 = 13 lM), and 9j (R2 = 3-Cl;
Azeto-pyrroloazepinones 8a–j and 9a–j were evaluated
in vitro for their ability to inhibit the growth of PC-3
prostate, U251 central nervous system, K652 leukemia,
HCT-15 colon, and MFC7 breast cancer cells. The per-
cent inhibition of growth of these five cell lines after
treatment with compounds 8a–j (100 lM) or 9a–j
(50 lM) is given in Tables 1 and 2, respectively.15
IC50 = 14 lM). Interestingly, the azetopyrroloazepinon-
13
es 7 demonstrated a similar tendency
against K-562
cells. In the U-251 central nervous system cancer cell
line, all the 9a–j compounds, except for 9e ((R2 = 4-F),
9f (R2 = 4-CH3) and 9g (R2 = 4-OMe), were significantly
more potent than lead compound 3. In particular, the
1-(4-nitrophenyl) derivative 9h was the most active
compound, and the unsubstituted derivatives 9a and
9e (R2 = 4-F) were selectively cytotoxic to these cells.
The HCT-15 cell line was sensitive to several of the pyr-
roloazepinones (9b, 9d, 9h, 9i, and 9j). The halogen
As shown in Table 1, the 2-methylpyrroloazepinones
8a–j (R1 = CH3) did not inhibit the proliferation of the
five cancer cell lines, indicating that the azeto ring is nec-
essary for cytotoxic activity for this series of com-
pounds. However, replacement of the 2-methyl
substituent of 8a–j (R1 = CH3) with a 2-(4-nitrophenyl)
moiety (compounds 9a–j) improved their cytotoxic
potency. Notably, the 1-(3-chlorophenyl) derivative 9j
Table 1. % Inhibition of compounds 8a–j to the five cancer cell lines (100 lM)
Compound
R2
PC-3 (prostate)
U-251 (CNS)
K-562 (leukemia)
HCT-15 (colon)
MCF-7 (breast)
8a
8b
8c
8d
8e
8f
4-H
4-I
7.55
20.43
14.73
19.98
14.25
28.46
ꢀ5.40
21.79
10.52
24.30
41.13
39.47
10.86
30.59
17.16
22.43
ꢀ18.78
1.25
ꢀ9.92
ꢀ29.33
ꢀ20.43
ꢀ3.87
ꢀ21.20
ꢀ23.47
10.23
19.31
23.20
ꢀ3.73
13.73
ꢀ3.85
ꢀ4.12
ꢀ4.26
27.70
28.87
24.34
4-Br
4-Cl
ꢀ2.38
31.01
4-F
ꢀ9.59
ꢀ13.29
ꢀ25.77
23.76
4-CH3
4-OCH3
4-NO2
3-Br
8g
8h
8i
12.30
ꢀ3.45
42.21
42.27
ꢀ15.80
17.0
12.04
41.40
23.38
8j
3-Cl
Table 2. % Inhibition of compounds 9a–j to the five cancer cell lines (50 lM)
Compound
R2
PC-3 (prostate)
U-251 (CNS)
K-562 (leukemia)
HCT-15 (colon)
MCF-7 (breast)
9a
9b
9c
9d
9e
9f
H
4-I
37.36
113.30
108.66
117.44
ꢀ5.43
ꢀ16.73
11.80
62.41
117.70
115.97
114.54
52.30
42.90
22.87
46.51
9.79
66.52
48.40
97.94
18.21
9.90
37.60
74.81
39.03
133.27
40.42
43.39
46.28
31.10
125.93
82.89
4-Br
4-Cl
4-F
94.76
ꢀ31.09
ꢀ40.31
ꢀ23.50
34.00
4-CH3
4-OCH3
4-NO2
3-Br
3-Cl
17.56
57.02
9g
9h
9i
21.79
51.84
103.36
81.87
84.24
111.3
134.91
110.92
100.60
117.29
88.62
85.91
9j
Table 3. The IC50 values (lM) of compounds 9a–j to the five cancer cell linesa
Compound
R2
PC-3 (prostate)
U-251 (CNS)
K-562 (leukemia)
HCT-15 (colon)
MCF-7 (breast)
3
NA
87.0 8.6
>100
40.0 3.6
12.4 0.2
15.5 4.1
25.6 4.5
28.82 3.7
35.1 7.3
>100
>100
>100
>100
>100
>100
>100
9a
9b
9c
9d
9e
9f
H
4-I
10.13 0.56
21.1 2.1
17.44 1.87
>100
>100
>100
63.3 12.5
>100
14.3 1.3
>100
4-Br
4-Cl
4-F
15.10 3.9
>100
>100
20.04 4.7
>100
>100
51.66 3.6
>100
>100
4-CH3
4-OMe
4-NO2
3-Br
3-Cl
>100
>100
9g
9h
9i
87.0 17.0
8.7 1.2
>100
>100
>100
>100
>100
14.3 3.1
10.11 0.73
6.3 0.5
0.32 0.02
57.3 10.4
10.5 1.3
33.6 4.5
0.23 0.01
14.8 0.12
20.7 0.9
0.09 0.02
12.6 2.3
13.7 1.5
0.28 0.01
13.3 2.1
11.8 3.8
0.14 0.01
9j
Doxo
a The tumoral cell lines were supplied by the National Cancer Institute. The cytotoxic assay were carried out at 5000–7500 cells/mL using the
sulforhamide B (SRB) protein assay to estimate cell growth. The percentage growth was evaluated spectrophotometrically in a Bio kinetics reader
spectrophotometer. Values are means of three experiments, standard deviation is given in parentheses (>100, not active). Doxo, doxorubicine.

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R. Martınez et al. / Bioorg. Med. Chem. 14 (2006) 4007–4016
4011
derivatives 9b (R2 = 4-I; IC50 = 14 lM), 9i (R2 = 3-Br;
IC50 = 13 lM), and 9j (R2 = 3-Cl; IC50 = 12 lM) were
effective in killing breast cancer cell lines (MFC-7) with
moderate micromolar cytotoxicity, suggesting that
derivatization of N-phenyl group with these halogens
is suitable to obtain best anticancer compounds. Thus,
the antiproliferative activity of 9i in HCT-15 and
MCF-7 cells resembles its potency in the PC-3, U-251,
and K-562 cancer cell lines.
trometers. Reaction mixtures and chromatography frac-
tions were concentrated by using a rotary evaporator
(ca. 20 ꢁC/20 Torr). For column chromatography, the
Merck silica gel 60 F254 was employed. Commercial
grade reagents were used without further purification
except when indicated.
5.1.1. General procedure for the synthesis of cyclohex-1-
ones (10 and 11). A slurry of dimedone (0.01 equiv),
chloroketone (0.01 equiv), and anhydrous potassium
carbonate (0.01 equiv) in chloroform was kept stirred
at room temperature for 48 h. The mixture was filtered;
the insoluble salts were dissolved in water and the fil-
tered solution was made acidic with concentrated HCl.
The precipitate was filtered off, washed with water,
and crystallized from aqueous alcohol.
Because it was reported that the HCT-116 cancer cell
line was the most sensitive to the growth inhibitory
activity of paullones 1 and compounds 9a–j were tested
on its parental HCT-15 cancer cell line, a comparison of
their cytotoxic activity was made . Compounds 9a–j
exhibit a similar antiproliferative activity (IC50 in the
low micromolar range) as kenpaullone 1a (GI50
20 lM). In contrast, alsterpaullone 1b (R = NO2; GI50
0.2 lM)) shows a more than 10-fold higher potency
compared to 9a–j compounds. Unfortunately, com-
pounds 8c, 8d, 8i, 8j, and 9a–j did not inhibit the protein
kinase activity of CDK1/cyclin B, CDK5/p25, and
GSK-3 CDK1 (IC50 > 10 lM),16 and these results do
not allow it to give a reasonable mechanistic explanation
of cytotoxic behavior of 9a–j.
3-Hydroxy-5,5-dimethyl-2-(2-oxopropyl)-2-cyclohex-1-
one 10: yield 70% as a white solid; mp 133–134 ꢁC. (lit.17
1
135–137 ꢁC); H NMR (CDCl3, 200 MHz) d 1.08 (6H,
s), 2.16 (3H, s), 2.35 (4H, s), 3.41(2H, s), 9.0 (1H, s, br).
3-Hydroxy-5,5-dimethyl-2-[2-(4-nitrophenyl)-2-oxoeth-
yl]-2-cyclohex-1-one 11: yield 75% as a white solid; mp
198–200 ꢁC (lit.18 202–204 ꢁC); 1H NMR (CDCl3,
200 MHz) d 1.07 (6H, s), 2.30 (4H, s), 3.92 (2H, s),
8.12 (2H, m), 8.27 (2H, m).
4. Conclusion
5.1.2. Synthesis of 1-(R2-phenyl)-2,6,6-trimethyl-4,5,6,7-
tetrahydroindol-4-ones (12a–j). General procedure
(R2 = H): To a vigorously stirred suspension of trike-
tone 10 (0.20 mmol) in acetic acid (5 mL) was added ani-
line (0.25 mmol). The resulting slurry was refluxed
overnight until no more starting material was observed
by TLC and then the reaction mixture was allowed to
warm to room temperature and spilled over ice-water
(10 mL). The aqueous solution was treated with a 10%
sodium bicarbonate solution until a precipitate ap-
peared. Purification by flash column chromatography
on silica using hexane/ethyl acetate (7:3) as the eluent li-
quid afforded 12a as a colorless solid (70% yield), mp:
135–137 ꢁC, mp lit.,19 135–138 ꢁC; IR (CHCl3) mmax
(cmꢀ1) 1648; 1H NMR (CDCl3, 200 MHz) d 1.06
(H-9,90), 2.04 (H-8), 2.35 (H-5), 2.37 (H-7), 6.36 (H-3),
6.9–7.2 (Ar-H); MS (EI) m/z 253.
The present results indicate that removal of the azeto
moiety from lead compound 3 (compounds 8a–j;
R1 = CH3) dramatically reduces the cytotoxic activity.
However, this is less clear in the case of azepinones
9a–j (R1 = 4-nitrophenyl) which, in most cases, inhibited
the proliferation of all five cancer cell lines despite
lacking the azeto ring. The preliminary SAR for these
compounds also revealed the importance of halogens
in para or meta positions on the 1-phenyl moiety. Addi-
tionally, derivatives 9a (R2 = H), 9e (R2 = 4-F), and 9g
(R2 = 4-OMe) were selectively cytotoxic to U-251 cells.
Therefore, our results indicate that these new cytotoxic
compounds may be useful as lead compounds for the
development of novel anticancer agents. Unfortunately,
compounds 9a–j did not inhibit protein kinase activity.
Therefore, future studies will focus on determining the
mechanism by which these new pyrroloazepinones
inhibit tumor growth and investigating the effect of com-
binations of appropriately positioned substituents.
5.1.3. 1-(4-Iodophenyl)-2,6,6-trimethyl-4,5,6,7-tetrahydro-
indol-4-one (12b). Yield: 84%; mp: 170–172 ꢁC; mp lit.,13
1
172–173 ꢁC; IR (CHCl3) mmax (cmꢀ1) 1648; H NMR
(CDCl3, 200 MHz) d 1.06 (H-9,90), 2.04 (H-8), 2.35
(H-5), 2.38 (H-7), 6.36 (H-3), 6.9–7.87 (Ar-H); MS
(EI) m/z 379.
5. Experimental
5.1. Chemistry
5.1.4. 1-(4-Bromophenyl)-2,6,6-trimethyl-4,5,6,7-tetra-
hydroindol-4-one (12c). Yield: 86%; mp: 171–173 ꢁC,
mp lit.,13 171–173 ꢁC; IR (CHCl3) mmax (cmꢀ1) 1648;
1H NMR (CDCl3, 200 MHz) d 1.05 (H-9,90), 2.04
(H-8), 2.35 (H-5), 2.37 (H-7), 6.37 (H-3), 7.08–7.67
(Ar-H); MS (EI) m/z 331.
Melting points were determined on a Melt-Tem II melt-
ing points apparatus and are uncorrected. The IR spec-
tra were determined in a Nicolet FT Magna-IR 750
spectrometer. The H1 and 13C NMR were determined
in Varian Gemini 200 and UNITY-300 spectrometers
in deuteriochloroform solution containing tetrameth-
ylsilane as the internal standard with chemical shifts
(d) expressed downfield from TMS. Mass spectra were
obtained with AX505-HA and SX-100 Jeol mass spec-
5.1.5. 1-(4-Chlorophenyl)-2,6,6-trimethyl-4,5,6,7-tetra-
hydroindol-4-one (12d). Yield: 86%; mp: 171–172 ꢁC,
mp lit.,20 170–172 ꢁC; IR (CHCl3) mmax (cmꢀ1) 1649;

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R. Martınez et al. / Bioorg. Med. Chem. 14 (2006) 4007–4016
4012
1H NMR (CDCl3, 200 MHz) d 1.07(H-9, 90), 2.05 (H-8),
2.36 (H-5), 2.39 (H-7), 6.36 (H-3),7.14–7.65 (Ar-H); MS
(EI) m/z 287.
5.2.1. 6,6-Dimethyl-2-(4-nitrophenyl)-1-(4-iodophenyl)-
1,5,6,7-tetrahydroindol-4-one (13b). Yield 60%; mp:
1
174–175 ꢁC, mp lit.,21 173–175 ꢁC; H NMR (CDCl3,
200 MHz) d 1.11 (H-8,80), 2.43 (H-5), 2.52 (H-7), 6.95
(H-3), 7.10–8.05 (Ar-H). MS: m/z 486.
5.1.6.
1-(4-Fluorophenyl)-2,6,6-trimethyl-4,5,6,7-tetra-
hydroindol-4-one (12e). Yield: 83%; mp: 156–158 ꢁC,
mp lit.,19 155–157 ꢁC; IR (CHCl3) mmax (cmꢀ1) 1648;
1H NMR (CDCl3, 200 MHz) d 1.06 (H-9,90), 2.04
(H-8), 2.35 (H-5), 2.37 (H-7), 6.36 (H-3), 6.9–7.2
(Ar-H); MS (EI) m/z 271.
5.2.2. 6,6-Dimethyl-2-(4-nitrophenyl)-1-(4-bromophenyl)-
1,5,6,7-tetrahydroindol-4-one (13c). Yield 65%; mp:
227–228 ꢁC, mp lit.,21 224–225 ꢁC1H NMR (CDCl3,
200 MHz) d 1.11 (H-8,80), 2.43 (H-5), 2.51 (H-7), 6.95
(H-3), 7.04–8.08 (Ar-H). MS: m/z 438.
5.1.7. 1-(4-Methylphenyl)-2,6,6-trimethyl-4,5,6,7-tetra-
hydroindol-4-one (12f). Yield: 80%; mp: 170–171 ꢁC,
mp lit.,20 170–172 ꢁC; IR (CHCl3) mmax (cmꢀ1) 1648;
1H NMR (CDCl3, 200 MHz) d 1.06 (H-9,90), 2.04
(H-8), 2.35 (H-5), 2.37 (H-7), 2.44 (4-CH3-Ar), 6.36
(H-3), 6.9–7.22 (Ar-H); MS (EI) m/z 267.
5.2.3. 6,6-Dimethyl-2-(4-nitrophenyl)-1-(4-chlorophenyl)-
1,5,6,7-tetrahydroindol-4-one (13d). Yield 67%; mp: 251–
253 ꢁC, mp lit.21 246–247 ꢁC; 1H NMR (CDCl3,
200 MHz) d 1.11 (H-8,80), 2.43 (H-5), 2.53 (H-7), 6.95
(H-3), 7.12–8.07 (Ar-H). MS: m/z 394.
5.2.4. 6,6-Dimethyl-2-(4-nitrophenyl)-1-(4-fluorophenyl)-
1,5,6,7-tetrahydroindol-4-one, (13e). Yield 66%; mp:
5.1.8. 1-(4-Methoxyphenyl)-2,6,6-trimethyl-4,5,6,7-tetra-
hydroindol-4-one (12g). Yield: 81%; mp: 143–145 ꢁC, mp
lit.,20 142–144 ꢁC; IR (CHCl3) mmax (cmꢀ1) 1648; 1H
NMR (CDCl3, 200 MHz) d 1.06 (H-9,90), 2.04 (H-8),
2.35 (H-5), 2.37 (H-7), 2.42 (4-CH3-Ar), 6.36 (H-3),
3.81 (4-OCH3-Ar), 7.0–7.22 (Ar-H); MS (EI) m/z 283.
1
277–279 ꢁC, mp lit.,21 280–281 ꢁC; H NMR (CDCl3,
200 MHz) d 1.11 (H-8,80), 2.43 (H-5), 2.51 (H-7), 6.96
(H-3), 7.16–8.07 (Ar-H). MS: m/z 378.
5.2.5. 6,6-Dimethyl-2-(4-nitrophenyl)-1-(4-methylphenyl)-
1,5,6,7-tetrahydroindol-4-one (13f). Yield 65%; mp: 262–
264 ꢁC, mp. lit.,21 260–262 ꢁC; 1H NMR (CDCl3,
200 MHz) d 1.10 (H-8,80), 2.42 (4-CH3-Ar), 2.44 (H-5),
2.52 (H-7), 6.96 (H-3), 7.02–8.05 (Ar-H). MS: m/z 374.
5.1.9.
1-(4-Nitrophenyl)-2,6,6-trimethyl-4,5,6,7-tetra-
hydroindol-4-one (12h). Yield 75%; mp: 178–180 ꢁC,
mp lit.,20 177–179 ꢁC; IR (CHCl3) mmax (cmꢀ1) 1649;
1H NMR (CDCl3, 200 MHz) d 1.07 (H-9, 90), 2.05
(H-8), 2.36 (H-5), 2.39 (H-7), 6.39 (H-3), 7.14–8.02
(Ar-H); MS (EI) m/z 298.
5.2.6. 6,6-Dimethyl-2-(4-nitrophenyl)-1-(4-methoxylphe-
nyl)-1,5,6,7-tetrahydroindol-4-one (13g). Yield 70%; mp:
1
200–202 ꢁC, mp lit.,21 205–207 ꢁC; H NMR (CDCl3,
5.1.10. 1-(3-Bromophenyl)-2,6,6-trimethyl-4,5,6,7-tetra-
hydroindol-4-one (12i). Yield 70%; mp 134–136 ꢁC, mp
lit.,20 134–135 ꢁC; IR (CHCl3) mmax (cmꢀ1) 1649; 1H
NMR (CDCl3, 200 MHz) d 1.07 (H-9, 90), 2.05 (H-8),
2.35 (H-5), 2.39 (H-7), 6.36 (H-3), 7.09–7.48 (Ar-H);
MS (EI) m/z 331.
200 MHz) d 1.11 (H-8,80), 2.42 (H-5), 2.51 (H-7), 3.78
(4-OCH3-Ar), 6.95 (H-3), 6.94–8.05 (Ar-H). MS: m/z
390.
5.2.7. 6,6-Dimethyl-bis-1,2-(4-nitrophenyl)-1,5,6,7-tetra-
hydroindol-4-one (13h). Yield 55%; mp: 275–277 ꢁC,
1
mp lit.,21 269–270 ꢁC; H NMR (CDCl3, 200 MHz) d
1.12 (H-8,80), 2.45 (H-5), 2.57 (H-7), 6.99 (H-3), 7.18–
8.36 (Ar-H). MS: m/z 405.
5.1.11. 1-(3-Chlorophenyl)-2,6,6-trimethyl-4,5,6,7-tetra-
hydroindol-4-one (12j). Yield 70%; mp 130–132 ꢁC, mp
lit.,13 129–131 ꢁC; IR (CHCl3) mmax (cmꢀ1) 1649; 1H
NMR (CDCl3, 200 MHz) d 1.07 (H-9, 90), 2.05 (H-8),
2.36 (H-5), 2.39 (H-7), 6.36 (H-3),7.14–7.65 (Ar-H);
MS (EI) m/z 287.
5.2.8. 6,6-Dimethyl-2-(4-nitrophenyl)-1-(3-bromophenyl)-
1,5,6,7-tetrahydroindol-4-one (13i). Yield 60%; mp: 223–
225 ꢁC, mp lit.,21 226–227 ꢁC; 1H NMR (CDCl3,
200 MHz) d 1.12 (H-8,80), 2.43 (H-5), 2.45 (H-7), 6.95
(H-3), 7.09–8.08 (Ar-H). MS: m/z 438.
5.2. Synthesis of 6,6-dimethyl-2-(4-nitrophenyl)-1-(R2-
phenyl)-1,5,6,7-tetrahydroindol-4-ones (13a–j)
5.2.9. 6,6-Dimethyl-2-(4-nitrophenyl)-1-(3-chlorophenyl)-
1,5,6,7-tetrahydroindol-4-one (13j). Yield 65%; mp: 224–
225 ꢁC, mp lit.,21 225–227 ꢁC; 1H NMR (CDCl3,
200 MHz) d 1.12 (H-8,80), 2.43 (H-5), 2.54 (H-7), 6.96
(H-3), 7.04–8.08 (Ar-H). MS: m/z 394.
General procedure (R2 = H). To a reaction vessel with a
reflux condenser were successively added 5,5-dimethyl-
2[2-(4-nitrophenyl)-2-oxoethyl]cyclohexane-1.3-diona
(0.20 mmol), zirconium sulfate (0.080 g), aniline
(0.02 mL), and toluene (3 mL). After the resulting mix-
ture was stirred at 100 ꢁC for 3 h, the zirconium sulfate
was separated by filtration. The filtrate was concentrat-
ed and subjected to column chromatography on silica
gel with a mixture of n-hexane and ethyl acetate (3:1)
giving 13a as a colorless solid (80% yield), mp: 246–
248 ꢁC, mp lit.,21 245–246 ꢁC; 1H NMR (CDCl3,
200 MHz) d 1.11 (H-8,80), 2.43 (H-5), 2.54 (H-7), 6.97
(H-3), 7.16 - 8.01 (Ar-H); MS m/z 360.
5.2.10. Synthesis of 1-(R2-phenyl)-2,6,6-trimethyl-4,5,6,7-
tetrahydroindol-4-one (syn/anti) oximes (14a–j) and
1-(R2-phenyl)-6,6-dimethyl-2-(4-nitrophenyl)-1,5,6,7-tet-
rahydro-indol-4-one (syn/anti) oximes (15a–j). General
procedure (R2 = H). To a solution of 12a (1.26 mmol)
dissolved in 50 mL of ethanol was added a solution of
hydroxylamine hydrochloride(5.5 mmol) dissolved in
30 mL of 5 M sodium hydroxide and the mixture was

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R. Martınez et al. / Bioorg. Med. Chem. 14 (2006) 4007–4016
4013
stirred on a steam bath for two hours. Removal of the
solvent under reduced pressure gave an amorphous solid
that was purified by column chromatography on silica
gel with a mixture of n-hexane and ethyl acetate (6:4)
giving 14a as a colorless solid (97% yield); mp: 188–
190 ꢁC, mp lit.,14 186–190 ꢁC; d 0.91–0.93 (H-9,90),
2.04–2.27 (H-8), 2.58–2.25 (H-5), 2.24 (H-7), 6.24–6.81
(H-3), 7.17–7.45 (Ar-H); MS (EI) m/z 268.
2.29–2.61 (H-5), 2.36 (H-7), 6.33–6.82 (H-3), 7.12–7.62
(Ar-H); MS (EI) m/z 346.
5.2.10.9. 1-(3-Chlorophenyl)-2,6,6-trimethyl-4,5,6,7-
tetrahydroindol-4-one oximes (syn/anti) (14j). Yield 99%;
mp: 175–180 ꢁC, mp lit.,14 185–187 ꢁC; 1H NMR
(CDCl3, 200 MHz) d 0.99–1.02 (H-9,90), 1.96–2.26
(H-8), 2.21–2.61 (H-5), 2.12 (H-7), 6.23–6.83 (H-3),
7.25–7.84 (Ar-H); MS (EI) m/z 302.
5.2.10.1. 1-(4-Iodophenyl)-2,6,6-trimethyl-4,5,6,7-tet-
rahydroindol-4-one oximes (syn/anti) (14b). Yield 98%;
mp: 210–212 ꢁC, mp lit.,13 210–212 ꢁC; 1H NMR
(CDCl3, 200 MHz) d 0.92–0.96 (H-9,90), 2.05–2.35 (H-
8), 2.37 (H-7), 2.25–2.58 (H-5), 2.37 (H-7), 6.23–6.82
(H-3), 6.9–7.87 (Ar-H); MS (EI) m/z 394.
5.2.10.10. 6,6-Dimethyl-2-(4-nitrophenyl)-1-phenyl-
1,5,6,7-tetrahydro-indol-4-one oximes (syn/anti) (15a).
Yield 80%; mp: 240–242 ꢁC, IR (CHCl3, cmꢀ1) 3587;
1H NMR (CDCl3, 200 MHz) d 1.034–1.045 (H-8,80),
2.36 (H-7), 2.39–2.59 (H-5), 6.86 (H-3), 7.06–8.04
(Ar-H); MS 375.
5.2.10.2. 1-(4-Bromophenyl)-2,6,6-trimethyl-4,5,6,7-
tetrahydroindol-4-one oximes (syn/anti) (14c). Yield
5.2.10.11. 6,6-Dimethyl-2-(4-nitrophenyl)-1-(4-iodo-
phenyl)-1,5,6,7-tetrahydroindol- 4-one oximes (syn/anti)
1
97%; mp: 209–210 ꢁC, mp lit.,14 208–210 ꢁC; H NMR
(CDCl3, 200 MHz) d 0.91–0.94 (H-9,90), 2.06–2.28
(H-8), 2.25–2.58 (H-5), 2.24 (H-7), 6.25–6.83 (H-3),
7.08–7.62 (Ar-H); MS (EI) m/z 346.
(15b). Yield 75%; mp: 265–267 ꢁC, IR (CHCl3, cmꢀ1
)
3587; 1H NMR (CDCl3, 200 MHz) d 1.034–1.045
(H-8,80), 2.36 (H-7), 2.39–2.59 (H-5), 6.86 (H-3), 7.06–
8.04 (Ar-H); MS 501.
5.2.10.3. 1-(4-Chlorophenyl)-2,6,6-trimethyl-4,5,6,7-
tetrahydroindol-4-one oximes (syn/anti) (14d). Yield
5.2.10.12. 6,6-Dimethyl-2-(4-nitrophenyl)-1-(4-bromo-
phenyl)-1,5,6,7-tetrahydroindol-4-one oximes syn/anti)
1
99%; mp: 186–188 ꢁC, mp lit.,13 185–187 ꢁC; H NMR
(CDCl3, 200 MHz) d 0.90–0.93 (H-9,90), 2.06–2.25
(H-8), 2.27–2.58 (H-5), 2.28 (H-7), 6.25–6.82 (H-3),
7.11–7.48 (Ar-H); MS (EI) m/z 302.
(15c). Yield 89%; mp: 265–267 ꢁC, IR (CHCl3, cmꢀ1
)
3587; 1H NMR (CDCl3, 200 MHz) d 1.034–1.045
(H-8,80), 2.36 (H-7), 2.39–2.59 (H-5), 6.86 (H-3), 7.06–
8.04 (Ar-H); MS 453.
5.2.10.4. 1-(4-Fluorophenyl)-2,6,6-trimethyl-4,5,6,7-
tetrahydroindol-4-one oximes (syn/anti) (14e). Yield
5.2.10.13. 6,6-Dimethyl-2-(4-nitrophenyl)-1-(4-chloro-
phenyl)-1,5,6,7-tetrahydroindol-4-one oximes (syn/anti)
1
95%; mp: 212–214 ꢁC, H NMR (CDCl3, 200 MHz) d
0.93–0.95 (H-9,90), 2.04–2.22 (H-8), 2.57(H-7), 2.27–
2.58 (H-5), 6.21–6.80 (H-3), 7.18–7.26 (Ar-H); MS (EI)
m/z 286. C17H19FN2O; Anal. Calcd: C, 71.31; H, 6.69;
N, 9.78. Found C, 71.25; H, 6.65; N, 9.73.
(15d). Yield 95%; mp: 231–233 ꢁC, IR (CHCl3, cmꢀ1
)
3587; 1H NMR (CDCl3, 200 MHz)
d 1.06–1.07
(H-8,80), 2.39 (H-7), 2.43–2.70 (H-5), 6.91 (H-3), 7.07–
8.05 (Ar-H); MS 409.
5.2.10.5. 1-(4-Methylphenyl)-2,6,6-trimethyl-4,5,6,7-
tetrahydroindol-4-one oximes (syn/anti) (14f). Yield
5.2.10.14. 6,6-Dimethyl-2-(4-nitrophenyl)-1-(4-fluoro-
phenyl)-1,5,6,7-tetrahydroindol-4-one oximes (syn/anti)
1
96%; mp: 220–222 ꢁC, mp lit.,14 220–225 ꢁC, H NMR
(15e). Yield 86%; mp: 255–257 ꢁC, IR (CHCl3, cmꢀ1
)
1
(CDCl3, 200 MHz) d 0.92–0.94 (H-9,90), 2.03–2.24
(H-8); 2.24 (H-7), 2.25–2.56 (H-5), 6.19–6.78 (H-3),
7.05–7.24 (Ar-H); MS (EI) m/z 282.
3588; H NMR (CDCl3, 200 MHz) d 1.01 (H-8,80),
2.38 (H-7), 2.41–2.69 (H-5), 7.05 (H-3), 7.13–8.04
(Ar-H); MS 393.
5.2.10.6. 1-(4-Methoxyphenyl)-2,6,6-trimethyl-4,5,6,7-
tetrahydroindol-4-one oximes (syn/anti) (14g). Yield 97%;
mp: 213–215 ꢁC, mp lit.,14 212–213 ꢁC, 1H NMR
(CDCl3, 200 MHz) d 0.93–0.91 (H-9,90), 2.05–2.26
(H-8); 2.26 (H-7), 2.28–2.59 (H-5), 6.23–6.70 (H-3),
6.97–7.10 (Ar-H); MS (EI) m/z 298.
5.2.10.15. 6,6-Dimethyl-2-(4-nitrophenyl)-1-(4-methyl-
phenyl)-1,5,6,7-tetrahydroindol-4-one oximes (syn/anti)
(15f). Yield 89%; mp: 224–225 ꢁC, IR (CHCl3, cmꢀ1
)
3587; 1H NMR (CDCl3, 200 MHz)
d 1.06–1.07
(H-8,80), 2.39 (H-7), 2.43–2.66 (H-5), 6.94 (H-3), 2.42
(H-R), 7.0–8.0 (Ar-H); MS 389.
5.2.10.7. 1-(4-Nitrophenyl)-2,6,6-trimethyl-4,5,6,7-tet-
rahydroindol-4-one oximes (syn/anti) (14h). Yield: 95%;
mp: 256–258 ꢁC, mp lit.,10 255–258 ꢁC, 1H NMR
(CDCl3, 200 MHz) d 0.92–0.94 (H-9,90), 2.10–2.29
(H-8); 2.26 (H-7), 2.12–2.37 (H-5), 6.30–6.90 (H-3),
7.30–8.40 (Ar-H); MS (EI) m/z 313.
5.2.10.16. 6,6-Dimethyl-2-(4-nitrophenyl)-1-(4-meth-
oxyphenyl)-1,5,6,7-tetrahydro-indol-4-one oximes (syn/
anti) (15g). Yield 88%; mp: 267–269 ꢁC, IR (CHCl3,
1
cmꢀ1) 3587; H NMR (CDCl3, 200 MHz) d 1.067–1.07
(H-8,80), 2.39 (H-7), 2.44–2.66 (H-5), 6.95 (H-3), 3.87
(H-R), 7.04–8.02 (Ar-H); MS 405.
5.2.10.8. 1-(3-Bromophenyl)-2,6,6-trimethyl-4,5,6,7-
tetrahydroindol-4-one oximes (syn/anti) (14i). Yield
5.2.10.17. 6,6-Dimethyl-1,2-bis-(4-nitrophenyl)-
1,5,6,7-tetrahydroindol-4-one oximes (syn/anti) (15h).
Yield 77%; mp: 227–229 ꢁC, IR (CHCl3, cmꢀ1) 3586;
1H NMR (CDCl3, 200 MHz) d 1.05–1.06 (H-8,80), 2.40
1
95%; mp: 174–176 ꢁC, mp lit.,13 174–175 ꢁC; H NMR
(CDCl3, 200 MHz) d 1.03–1.04 (H-9, 90), 2.07 (H-8),

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R. Martınez et al. / Bioorg. Med. Chem. 14 (2006) 4007–4016
4014
(H-7), 2.43–2.63 (H-5), 6.94 (H-3), 7.19–8.34 (Ar-H);
MS 420.
NMR (CDCl3, 200 MHz) d 0.95 (H-10,100), 1.94
(H-9), 2.34 (H-8), 3.0 (H-6), 6.19 (exchangeable with
D2O, N–H), 6.47 (H-3), 7.10–7.601 (Ar-H); MS m/z
286, C17H19FN2O; Anal. Calcd: C, 71.31; H, 6.69; N,
9.78. Found: C,71.26; H, 6.66; N, 9.72.
5.2.10.18. 6,6-Dimethyl-2-(4-nitrophenyl)-1-(3-bromo-
phenyl)-1,5,6,7-tetrahydroindol-4-one oximes (syn/anti)
(15i). Yield 88%; mp: 248–250 ꢁC, IR (CHCl3, cmꢀ1
)
3586; 1H NMR (CDCl3, 200 MHz) d 1.047–1.057
(H-8,80), 2.33 (H-7), 2.38–2.59 (H-5), 6.87 (H-3), 7.17–
8.04 (Ar-H); MS 453.
5.2.11.5. 6H-1-(4-Methylphenyl)-2,7,7-trimethyl-
4,5,7,8-tetrahydropyrrolo[3,2-c]azepin-4-one (8f). Yield
95%; mp: 251–252 ꢁC, mp lit.,14 250–251 ꢁC; IR (CHCl3,
1
cmꢀ1) 1629; H NMR (CDCl3, 200 MHz) d 0.96 (H-10-
5.2.10.19. 6,6-Dimethyl-2-(4-nitrophenyl)-1-(3-chloro-
phenyl)-1,5,6,7-tetrahydroindol-4-one oximes (syn/anti)
100), 1.95 (H-9), 2.32 (H-8), 2.44 (CH3-Ar), 3.0 (H-6),
5.90 (exchangeable with D2O, N–H), 6.44 (H-3), 7.04–
7.28 (Ar-H); MS (EI) 282.
(15j). Yield 89%; mp: 245–246 ꢁC, IR (CHCl3, cmꢀ1
)
3587; 1H NMR (CDCl3, 200 MHz)
d 1.04–1.05
(H-8,80), 2.32 (H-7), 2.39–2.58 (H-5), 6.85 (H-3), 7.07–
8.04 (Ar-H); MS 409.
5.2.11.6.
6H-1-(4-Methoxylphenyl)-2,7,7-trimethyl-
4,5,7,8-tetrahydropyrrolo[3,2-c]azepin-4-one (8g). Yield
95%; mp: 231–232 ꢁC, mp lit.,14 230–231 ꢁC; IR (CHCl3,
1
5.2.11. Synthesis of 5,6,7,8-tetrahydro-2,7,7-trimethyl-1-
(R2- phenyl)pyrrolo[3,2-c]azepin-4 (1H)-ones (8a–j) and
5,6,7,8-tetrahydro-7,7-dimethyl-2-(4-nitro-phenyl)-1-(R2-
phenyl) pyrrolo[3,2-c]azepin-4(1H)-ones (9a–j). General
procedure (R2 = H): To a mixture of phosphorus pent-
oxide (7 mmol) and phosphoric acid (10 ml) was added
14a (3 mmol) and the mixture was mechanically stirred
at 80–90 ꢁC for 2 h. The mixture was treated with ice-
water, neutralized with sodium carbonate and extracted
with methylene chloride (3· 20 mL), and dried (sodium
anhydrous sulfate). Removal of the solvent under
reduced pressure gave an amorphous solid that was sep-
arated by column chromatography (silica gel, hexane/
ethyl acetate 6:4) to give 8a as a colorless solid (95%
yield); mp: 238–240 ꢁC, mp lit.,14 237–238 ꢁC; IR
(CHCl3 cmꢀ1) 1631; 1H NMR (CDCl3, 200 MHz) d
0.96 (H-10,100), 1.96 (H-9), 2.33 (H-8), 3.0 (H-6), 5.98
(exchangeable with D2O, N–H), 6.46 (H-3), 7.19–7.49
(Ar-H); MS (EI) m/z 268.
cmꢀ1) 1628; H NMR (CDCl3, 200 MHz) d 0.96 (H-10-
100), 1.95 (H-9), 2.32 (H-8), 2.44 (CH3-Ar), 3.0 (H-6),
3.88 (CH3O-Ar), 6.0 (exchangeable with D2O, N–H),
6.44 (H-3), 7.0-7.1 (Ar-H); MS (EI) 298.
5.2.11.7. 6H-1-(4-Nitrophenyl)-2,7,7-trimethyl-
4,5,7,8-tetrahydropyrrolo[3,2-c]azepin-4-one (8h). Yield
93%; mp: 253–255 ꢁC, mp lit.,10 250–255 ꢁC; IR (CHCl3,
1
cmꢀ1) 1638; H NMR (CDCl3, 200 MHz) d 0.98 (H-10-
100), 2.0 (H-9), 2.34 (H-8), 3.03 (H-6), 6.22 (exchange-
able with D2O, N-H), 6.52 (H-3), 7.41-8.40 (Ar-H);
MS (EI) 313.
5.2.11.8. 6H-1-(3-Bromophenyl)-2,7,7-trimethyl-
4,5,7,8-tetrahydropyrrolo[3,2-c]azepin-4-one (8i). Yield
94%; mp: 179–180 ꢁC, mp lit.,13 178–180 ꢁC; IR (CHCl3,
1
cmꢀ1) 1630; H NMR (CDCl3, 200 MHz) d 0.97 (H-10-
100), 1.97 (H-9), 2.32 (H-8), 3.02 (H-6), 6.22 (exchange-
able with D2O, N–H), 6.46 (H-3), 7.11–7.64 (Ar-H); MS
(EI) m/z 346.
5.2.11.1. 6H-1-(4-Iodophenyl)-2,7,7-trimethyl-4,5,7,8-
tetrahydropyrrolo[3,2-c]azepin-4-one (8b). Yield 96%;
mp: 264–265 ꢁC, mp lit.,13 264–2265 ꢁC; IR (CHCl3,
cmꢀ1) 1631; 1H NMR (CDCl3, 200 MHz) d 0.96
(H-10-100), 1.96 (H-9), 2.31 (H-8), 2.98 (H-6), 6.30
(exchangeable with D2O, N–H), 6.46 (H-3), 6.91–7.85
(Ar-H); MS (EI) m/z 394.
5.2.11.9. 6H-1-(3-Chlorophenyl)-2,7,7-trimethyl-
4,5,7,8-tetrahydropyrrolo[3,2-c]azepin-4-one (8j). Yield
96%; mp: 168–170 ꢁC, mp lit.,14 169–170 ꢁC; IR (CHCl3,
1
cmꢀ1) 1635; H NMR (CDCl3, 200 MHz) d 0.96 (H-10-
100), 1.96 (H-9), 2.33 (H-8), 3.0 (H-6), 6.02 (exchange-
able with D2O, N–H), 6.46 (H-3), 7.09–7.51 (Ar-H);
MS (EI) 302.
5.2.11.2. 6H-1-(4-Bromophenyl)-2,7,7-trimethyl-
4,5,7,8-tetrahydropyrrolo[3,2-c]azepin-4-one (8c). Yield
5.2.11.10. 7,7-Dimethyl-2-(4-nitro-phenyl)-1-phenyl-
94%; mp: 248–250 ꢁC, mp lit.,14 247–248 ꢁC; IR (CHCl3,
5,6,7,8-tetrahydro-1H-pyrrolo[3,2-c]azepin-4-one
(9a).
1
cmꢀ1) 1631; H NMR (CDCl3, 200 MHz) d 0.97 (H-10-
Yield 69%; mp: 250–252 ꢁC; IR (CHCl3, cmꢀ1) 1637;
1H NMR (CDCl3, 200 MHz) d 1.04 (H-9,90), 2.47
(H-8), 3.09 (H-6), 6.19 (exchangeable with D2O, N–H),
7.11 (H-3), 7.14–8.01 (Ar-H); MS (EI) 375.
C22H21N3O3; Anal. Calcd: C, 70.38; H, 5.64; N, 11.19.
Found: C,70.34; H, 5.63; N, 11.13.
100), 1.96 (H-9), 2.32 (H-8), 3.0 (H-6), 6.32 (exchange-
able with D2O, N–H), 6.46 (H-3), 7.07–7.65 (Ar-H);
MS (EI) m/z 346.
5.2.11.3. 6H-1-(4-Chlorophenyl)-2,7,7-trimethyl-4,5,7,8-
tetrahydropyrrolo[3,2-c]azepin-4-one (8d). Yield 95%; mp:
249–250 ꢁC, mp lit.,13 247–249 ꢁC; IR (CHCl3, cmꢀ1
)
5.2.11.11. 1-(4-Iodophenyl)-7,7-dimethyl-2-(4-nitro-
phenyl)-5,6,7,8-tetrahydro-1H-pyrrolo[3,2-c]azepin-4-one
1
1635; H NMR (CDCl3, 200 MHz) d 0.96 (H-10-100),
1.96 (H-9), 2.33 (H-8), 3.0 (H-6), 6.02 (exchangeable with
D2O, N-H), 6.46 (H-3), 7.09-7.51 (Ar-H); MS (EI) 302.
(9b). Yield 70%; mp: 305–307 ꢁC; IR (CHCl3, cmꢀ1
)
1
1638; H NMR (CDCl3, 200 MHz) d 1.03 (H-9,90),
2.43 (H-8), 3.12 (H-6), 6.45 (exchangeable with D2O,
N–H), 7.08 (H-3), 7.02–8.06 (Ar-H); MS 501.
C22H20IN3O3; Anal. Calcd: C, 52.71; H, 4.02; N, 8.38.
Found C, 52.72; H, 4.03; N, 8.33.
5.2.11.4. 6H-1-(4-Fluorophenyl)-2,7,7-trimethyl-
4,5,7,8- tetrahydropyrrolo[3,2-c]azepin-4-one (8e). Yield
90%; mp: 156–158 ꢁC; IR (CHCl3, cmꢀ1) 1637; 1H

´
R. Martınez et al. / Bioorg. Med. Chem. 14 (2006) 4007–4016
4015
5.2.11.12. 1-(4-Bromophenyl)-7,7-dimethyl-2-(4-nitro-
phenyl)-5,6,7,8-tetrahydro-1H-pyrrolo[3,2-c]azepin-4-one
5.2.11.19. 1-(3-Chloro-phenyl)-7,7-dimethyl-2-(4-nitro-
phenyl)-5,6,7,8-tetrahydro-1H-pyrrolo[3,2-c]azepin-4-one
(9c). Yield 70%; mp: 301–302 ꢁC; IR (CHCl3, cmꢀ1
)
(9j). Yield 78%; mp: 253–255 ꢁC; IR (CHCl3, cmꢀ1
)
1
1
1639; H NMR (CDCl3, 200 MHz) d 1.04 (H-9,90),
2.44 (H-8), 3.09 (H-6), 6.41 (exchangeable with D2O,
N–H), 7.08 (H-3), 7.03–8.04 (Ar-H); MS (EI) 453.
C22H20 BrN3O3; Anal. Calcd: C, 58.16; H, 4.44; N,
9.25. Found: C, 58.20; H, 4.43; N, 9.23.
1638; H NMR (CDCl3, 200 MHz) d 1.06 (H-9,90),
2.46 (H-8), 3.10 (H-6), 6.65 (exchangeable with D2O,
N–H), 7.27 (H-3), 7.05–8.08 (Ar-H); MS (EI) 409.
C22H20 ClN3O3; Anal. Calcd: C, 64.47; H, 4.92; N,
10.25. Found: C,64.45; H, 4.90; N, 10.22.
5.2.11.13. 1-(4-Chloro-phenyl)-7,7-dimethyl-2-(4-nitro-
phenyl)-5,6,7,8-tetrahydro-1H-pyrrolo[3,2-c]azepin-4-one
Acknowledgments
(9d). Yield 80%; mp: 272–274 ꢁC; IR (CHCl3, cmꢀ1
)
1638; 1H NMR (CDCl3, 200 MHz)
d
1.04
We are thankful to professor L. Meijer and Oliver Lo-
zach, CNRS, Station Biologique, Roscoff, France, for
`
the kinase assays that were supported by the Ministerie
de la Recherche/INSERM/ CNRS ‘Molecules et Cibles
(H-9,90), 2.44 (H-8), 3.09 (H-6), 6.48 (exchangeable with
D2O, N–H), 7.13 (H-3), 7.15–8.04 (Ar-H); MS (EI) 409.
C22H20ClN3O3; Anal. Calcd: C, 64.47; H, 4.92; N, 10.25.
Found: C,64.44; H, 4.90; N, 10.23.
`
´
Therapeutiques’ Programme. We also thank DGAPA-
UNAM (IN-211601) for financial support and
R. Patin˜o, H. Rios, A. Pen˜a, N. Zavala, L. Velasco,
5.2.11.14. 1-(4-Fluoro-phenyl)-7,7-dimethyl-2-(4-nitro-
phenyl)-5,6,7,8-tetrahydro-1H-pyrrolo[3,2-c]azepin-4-one
(9e). Yield 72% yield); mp: 283–284 ꢁC; IR (CHCl3,
cmꢀ1) 1637; 1H NMR (CDCl3, 200 MHz) d 1.05
(H-9,90), 2.45 (H-8), 3.11 (H-6), 6.45 (exchangeable with
D2O, N–H), 7.10 (H-3), 7.16–8.04 (Ar-H); MS (EI) 393.
C22H20 FN3O3; Anal. Calcd: C, 67.17; H, 5.12; N, 10.68.
Found: C,67.20; H, 5.10; N, 10.63.
´
and J. Perez for technical assistance. Contribution
No. 2633 from Instituto de Quımica, UNAM.
´
References and notes
1. Giordano A.; Romano G. Eds.; Cell Cycle Control and
Dysregulation Protocols: Cyclins, Cyclin-Dependent
Kinases, and Other Factors (Methods in Molecular
Biology); Humana: New Jersey, 2004.
2. Pevarello, P.; Villa, M. Expert Opin. Ther. Patents 2005,
15, 675–703.
5.2.11.15. 1-(4-Methylphenyl)-7,7-dimethyl-2-(4-nitro-
phenyl)-5,6,7,8-tetrahydro-1H-pyrrolo[3,2-c]azepin-4-one
(9f). Yield 72%; mp: 278–279 ꢁC; IR (CHCl3, cmꢀ1
)
1
1637; H NMR (CDCl3, 200 MHz) d 1.03 (H-9,90),
2.45 (H-8), 2.43 (H-CH3), 3.09 (H-6), 6.39 (exchangeable
with D2O, N–H), 7.09 (H-3), 7.03–8.01 (Ar-H); MS (EI)
389. C23H23N3O3; Anal. Calcd: C, 70.93; H, 5.95; N,
10.79. Found: C,70.95; H, 5.96; N, 10.73.
3. Kunick, C.; Lemcke, Th. Pharm. Ztg. 2002, 147,
2428–2435.
4. Meijer, L.; Thunnissen, A. M.; White, A. W.; Garnier, M.;
Nikolic, M.; Tsai, L. H.; Walter, J.; Cleverley, K. E.;
Salinas, P. C.; Wu, Y. Z.; Biernat, J.; Mandelkow, E. M.;
Kim, S. H.; Pettit, G. R. Chem. Biol. 2000, 7, 51–63.
5. Zaharevitz, D. W.; Gussio, R.; Leost, M.; Senderowicz, A.
M.; Lahusen, T.; Kunick, C.; Meijer, L.; Sausville, E. A.
Cancer Res. 1999, 59, 2566–2569.
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Lozach, O.; Bach, S.; Mayer, T.; Fabbro, D.; Meijer, L.;
Gray, N. S. Chem. Biol. 2004, 11, 247–259.
7. (a) 9-Bromo-7,12-dihydroindolo-[3,2-d][1]benzazepin-
6(5H)-one, kenpaullone, A.G. Scientific, Inc., <http://
www.agscientific.com/Item/K1050.htm>; (b) 9-Nitro-7,12-
dihydroindolo-[3,2-d][1]benzazepin-6(5H)-one, alsterpaul-
lone, A.G. Scientific, Inc, http://www.agscientific.com/
Item/A1136.htm.
8. (a) Gussio, R.; Zaharevitz, D.; McGrath, C.; Pattabir-
aman, N.; Kellog, G.; Schultz, C.; Link, A.; Kunick, C.;
Leost, M.; Meijer, L.; Sausville, E. Anti-Cancer Drug Des.
2000, 15, 53–66; (b) Sharma, V.; Lansdell, T. A.; Jin, G.;
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5.2.11.16. 1-(4-Methoxy-phenyl)-7,7-dimethyl-2-(4-ni-
tro-phenyl)-5,6,7,8-tetrahydro-1H-pyrrolo[3,2-c]azepin-4-
one (9g). Yield 70%; mp: 295–296 ꢁC; IR (CHCl3,
cmꢀ1) 1634; 1H NMR (CDCl3, 200 MHz) d 1.04
(H-9,90), 2.47 (H-8), 3.09 (H-6), 3.87(H-OCH3), 6.27
(exchangeable with D2O, N–H), 7.10 (H-3), 6.94–
8.02 (Ar-H); MS (EI) 405. C23H23N3O4; Anal. Calcd:
C, 68.13; H, 5.72; N, 10.36. Found: C, 68.15; H,
5.72; N, 10.33.
5.2.11.17. 7,7-Dimethyl-1,2-bis(4-nitro-phenyl)-
5,6,7,8-tetrahydro-1H-pyrrolo[3,2-c]azepin-4-one
(9h).
Yield 69%; mp: 307–308 ꢁC; IR (CHCl3, cmꢀ1) 1630;
1H NMR (CDCl3, 200 MHz) d 1.06 (H-9,90), 2.47
(H-8), 3.12 (H-6), 6.50 (exchangeable with D2O, N-H),
7.12 (H-3), 7.12–8.35 (Ar-H); MS (EI) 420.
C22H20N4O5; Anal. Calcd: C, 62.85; H, 4.79; N, 13.33.
Found C,62.87; H, 4.76; N, 13.34.
´
´
´
9. Chacon-Garcıa, L.; Martınez, R. Eur. J. Med. Chem.
2002, 37, 261–266.
10. (a) National Cancer Institute, Compound NSC 700497,
http://dtp.nci.nih.gov/docs/cancer/searches/cancer_open_com-
5.2.11.18. 1-(3-Bromo-phenyl)-7,7-dimethyl-2-(4-nitro-
phenyl)-5,6,7,8-tetrahydro-1H-pyrrolo[3,2-c]azepin-4-one
´
pounds.html; (b) Martınez, R.; Avila-Zarraga, J. G.;
Lopez-Lopez, G.; Nava-Salgado, V. O. Heterocycles
´
´
´
(9i). Yield 75%; mp: 252–253 ꢁC; IR (CHCl3, cmꢀ1
)
2000, 53, 557–570.
11. Proudfoot, J. R. Bioorg. Med. Chem. Lett. 2002, 12,
1647–1650.
1
1639; H NMR (CDCl3, 200 MHz) d 1.06 (H-9,90),
2.46 (H-8), 3.09 (H-6), 6.27 (exchangeable with D2O,
N–H), 7.27 (H-3), 7.12–8.05 (Ar-H); MS (EI) 453.
C22H20 BrN3O3; Anal. Calcd: C, 58.16; H, 4.44; N,
9.25. Found C, 58.18; H, 4.43; N, 9.26.
´
´
12. Martınez, R.; Avila-Zarraga, J. G.; Duran, M. E.;
Ramırez, Ma. T.; Can˜as, R. Bioorg. Med. Chem. Lett.
´
2002, 12, 1675–1677.

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R. Martınez et al. / Bioorg. Med. Chem. 14 (2006) 4007–4016
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17. Nagarajan, K.; David, J.; Shah, R. K. J. Med. Chem.
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18. (a) Nagarajan, K.; Talwalker, P.-K.; Shah, R. K.; Mehta,
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20. Martınez, R.; Avila-Zarraga, G.; Reyes, E. Synth. Com-
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