Synthesis, antitumor and antimicrobial activity of novel 1-substituted phenyl-3-[3-alkylamino(methyl)-2-thioxo-1,3,4-oxadiazol-5-yl] β-carboline derivatives

Article abstract of DOI:10.1590/S0103-50532010000200014

With the purpose of activity enhancement of 1-substituted phenyl-3-(2-thioxo-1,3,4-oxadiazol-5-yl) β-carbolines 1a-c, reported as potential antitumor agents in our previous study, herein we report the synthesis and antitumor activity evaluation of several novel Mannich bases 2-7(a-c), by the introduction of different alkylamino(methyl) groups in the 1,3,4-oxadiazole unity of 1a-c. The antimicrobial activities of 1a-c and of 2-7(a-c) were also evaluated. Additionally, an in silico study of the ADME properties of novel synthesized β-carboline derivatives 2-7(a-c) was performed by evaluation of their Lipinski's parameters and topological polar surface area (TPSA) and percentage of absorption (percent ABS) data.

Full text of DOI:10.1590/S0103-50532010000200014

J. Braz. Chem. Soc., Vol. 21, No. 2, 288-298, 2010.
Printed in Brazil - ©2010 Sociedade Brasileira de Química
0103 - 5053 $6.00+0.00
Synthesis, Antitumor and Antimicrobial Activity of Novel 1-Substituted
Phenyl-3-[3-alkylamino(methyl)-2-thioxo-1,3,4-oxadiazol-5-yl] b-Carboline Derivatives
Franciele C. Savariz,a Anelise S. N. Formagio,a Valéria A. Barbosa,a
Mary Ann Foglio,b João E. de Carvalho,b Marta C. T. Duarte,b
Benedito P. Dias Filhoc and Maria Helena Sarragiotto*,a
aDepartamento de Química and cDepartamento de Análises Clínicas,
Universidade Estadual de Maringá, 87020-900 Maringá-PR, Brazil
bCentro Pluridisciplinar de Pesquisas Químicas, Biológicas e Agrícolas,
Universidade Estadual de Campinas, CP 6171, 13083-970 Campinas-SP, Brazil
Com o propósito de aumentar a atividade anticâncer demonstrada anteriormente pelas
1-fenilssubstituído-3-(2-tioxo-1,3,4-oxadiazol-5-il) b-carbolinas 1a-c, neste trabalho foram
realizadas a síntese e a avaliaçãoin vitroda atividade antitumoral de novas bases de Mannich2-7(a-c),
derivadas da introdução de diferentes grupos alquilamino(metil) na unidade 1,3,4-oxadiazol de
1a-c. Os derivados 1a-c e 2-7(a-c) foram também avaliados quanto às atividades antibacteriana e
antifúngica.Adicionalmente, um estudo in silico das propriedades deADME dos novos compostos
sintetizados 2-7(a-c) foi realizado pela avaliação de seus parâmetros de Lipinski e de dados de
área de superfície topológica polar (TPSA) e de porcentagem de absorção (% ABS).
With the purpose of activity enhancement of 1-substituted phenyl-3-(2-thioxo-1,3,4-oxadiazol-
5-yl) b-carbolines 1a-c, reported as potential antitumor agents in our previous study, herein we
report the synthesis and antitumor activity evaluation of several novel Mannich bases 2-7(a-c), by
the introduction of different alkylamino(methyl) groups in the 1,3,4-oxadiazole unity of 1a-c. The
antimicrobial activities of 1a-c and of 2-7(a-c) were also evaluated.Additionally, an in silico study
of the ADME properties of novel synthesized b-carboline derivatives 2-7(a-c) was performed by
evaluation of their Lipinski’s parameters and topological polar surface area (TPSA) and percentage
of absorption (% ABS) data.
Keywords: 1,3-disubstituted b-carboline derivatives, 1,3,4-oxadiazole, Mannich bases,
antitumor activity, antimicrobial activity
Introduction
and substituents nature in C-1, C-3 and position -9 of
the b-carboline skeleton on activity.4,5 The presence of
appropriate substituents on these positions could lead to
more potent compounds with reduced toxicity.
The biological potential of b-carboline alkaloids
and the importance of the search for new antitumor and
antimicrobial agents have led us to study this class of
compounds. In previous work, we reported synthesis and in
vitro antitumor activities of a series of 1-substituted phenyl
b-carboline bearing 2-thioxo-1,3,4-oxadiazol-5-yl moiety
at C-3.14 The anticancer assay results pointed compounds
1a-c with growth inhibition effect (GI50 < 100 mmol L-1)
for all eight human cancer cell lines tested.14
b-Carboline alkaloids are a class of synthetic and
naturally occurring compounds that possess a large
spectrum of important pharmacological properties.1
Particularly, these compounds have shown antitumor
activity,1-10 acting mainly as intercalating into DNA.6-10Also,
synthetic and natural compounds of this class exhibited
antimicrobial activities, mainly against Bacillus subtilis,
Escherichia coli and Staphylococcus aureus bacteria and
against Candida albicans fungi.11-13
Studies on a variety of synthetic b-carboline derivatives
have demonstrated the influence of both molecule planarity
Taking in account our previous results and with the aim
of increasing the antitumor activity we have continued our
*e-mail: mhsarragiotto@uem.br

Vol. 21, No. 2, 2010
Savariz et al.
289
work on b-carboline derivatives 1, with the introduction of
substituents in 1,3,4-oxadiazole ring. Literature reports that
Mannich bases of oxadiazoles possess important activities,
such as antibacterial and anticancer.15-17
isopropylamine, butylamine, cyclohexylamine and
benzylamine, using ethanol as solvent, afforded the
Mannich bases 2a-c, 3a-c, 4a-c and 5a-c, respectively
(Scheme 1). Condensation reaction with pyrrolidine and
morpholine secondary amines under the same conditions,
afforded the Mannich bases 6a-c and 7a-c, respectively
(Scheme 1). The Mannich bases 2-7(a-c) were obtained
in range of 52% to 92% yields from 1a-c, and in six steps
from commercial L-tryptophan with 15-34% overall yields.
All novel compounds were characterized by their
Therefore, in this study we synthesized six series
of Mannich bases from the previously reported active
compounds 1a-c14 to investigate the effects of different
3-alkylamino(methyl) substituents on the oxadiazole ring,
expecting that the incorporation of these substituents
would lead to antitumor activity enhancement. More
specifically, we report the synthesis and in vitro anticancer
activity of b-carboline derivatives 2-7(a-c) bearing a
3-alkylamino(methyl)-2-thioxo-1,3,4-oxadiazol-5-yl group
at C-3.Additionally, the antimicrobial activities of 1a-c and
of the Mannich bases 2-7(a-c) were evaluated.
An in silico study of the ADME properties of novel
synthesized b-carboline derivatives was carried out by
investigation of their Lipinski’s parameters, topological
polar surface area (TPSA) and percentage of absorption
(% ABS).18,19
1
13
spectroscopic data (IR, EIMS, H and C NMR), which
are described in the Experimental section.
The formation of Mannich bases 2-7(a-c) was
evidenced by the presence of a singlet at dH 5.00-6.00 in the
1H NMR spectra, corresponding to the methylene exocyclic
hydrogens of the alkylamino(methyl) group introduced at
N-3 of the 1,3,4-oxadiazole ring, together with the signals
for each group alkylamino. The exocyclic methylene carbon
of the alkylamino group appears in the region of dC 60-70
in the 13C NMR. The signals in the dC 177 and 160 region
were assigned for C-2 and C-5 carbons, respectively, of the
1,3,4-oxadiazole ring.
Results and Discussion
The IR spectra showed absorption bands characteristic
for N-H indole and C=N stretching in the 3040 and
1615 cm-1 region, respectively, and for C=S group at 1390
and 1240 cm-1.
The structures of 2-7(a-c) were also confirmed by EI
mass spectra. The majority of compounds showed the
presence of a base peak at m/z [M+·- alkylamino(methyl)-
Chemistry
The 3-(2-thioxo-1,3,4-oxadiazol-5-yl) b-carbolines
1a-c were prepared from the commercial L-tryptophan
as previously reported.14 The condensation reaction of
1a-c, formaldehyde 37%15,17 and the primary amines
Scheme 1. Synthesis of compounds 2-7 (a-c).

290
Synthesis, Antitumor and Antimicrobial Activity
J. Braz. Chem. Soc.
thioxo-1,3,4-oxadiazole] relative to cleavage between C-3
of b-carboline and C-5 of 1,3,4-oxadiazole ring. For the
benzyl derivatives 5a-c the base peaks were observed at
m/z 91, which was due to the tropilium ion formation.
activity spectrum at GI50 and TGI levels, with GI50 (MG-
MID) values of 5.89, 4.37 and 4.57 mmol L-1 (Table 1),
respectively. Moreover, compound 2a displayed cytotoxic
efficacy with LC50 (MG-MID) value of 60.49 mmol L-1
(Table 2).
Anticancer activity
A potent activity against melanoma (UACC-62) and
lung (NCI-460) cell lines, with GI50 values of 0.88 and
1.01 mmol L-1 (Table 1), respectively, was observed for
compound 2c, which possess the N,N-dimethylphenyl
and isopropylamino(methyl) groups at C-1 and C-3,
respectively, of the b-carboline nucleus. Compound 5c
also demonstrated a significant activity, with GI50 values in
the range of 0.38 and 2.98 µmol L-1 towards four cell lines
(melanoma, ovarian resistant, renal and lung).
Comparison of the GI50 (MG-MID) values for all tested
compounds showed that, except for 3b, 4c and 7c, the
Mannich bases derivatives displayed higher anticancer
activity than the corresponding precursors. For the most
active 2a, 2c and 5c Mannich bases, the introduction of an
alkylamino(methyl) group at N-3 of the heterocyclic ring
The GI50, TGI and LC50 data and MG-MID values
obtained for each compound and cell lines tested were
summarized in Tables 1 and 2. The anticancer assay results
pointed towards eleven compounds (2a, 2c, 3a, 5b, 5c, 6a-c
and 7a-c) with growth inhibition effect (GI50 < 100 mmol L-1)
for all eight human cancer cell lines tested, showing GI50
(MG-MID) values within 4.37 to 36.31 mmol L-1 range
(Table 1). Analysis of the TGI (MG-MID) values (Table 2)
showed that the Mannich bases synthesized were able to
inhibit total growth (cytostatic activity), except for 3b and
7c, in a concentration minor than 100 mmol L-1.
Among compounds tested, 2a, 2c and 5c were the
most active derivatives, exhibiting a broad antitumor
Table 1. GI50 values (in µmol L-1) and GI50 MG-MID (in µmol L-1) for compounds 1a-c and 2-7(a-c)
Compounds
Cancer cell line
Melanoma
UACC-62
Breast
MCF7
Ovarian
resistant
Renal
786-0
Lung
NCI-460
Prostate
PCO-3
Ovarian
OVCAR
Colon
HT29
MG-MIDa
NCI/ADR
Doxorubicin
0.43
>100
24.10
23.82
6.00
7.08
0.88
5.29
>100
10.34
8.89
7.58
8.74
>100
11.30
2.98
7.61
6.97
6.63
6.77
6.81
24.19
0.005
25.54
27.93
18.84
0.86
0.13
17.60
74.99
32.11
5.90
0.21
27.95
32.38
14.72
4.66
0.04
20.60
73.41
19.09
5.72
0.46
25.54
12.20
14.72
6.12
0.34
31.77
22.31
14.72
6.21
0.46
25.54
27.93
40.46
43.85
>100
22.06
49.80
>100
>100
>100
>100
>100
54.29
68.52
56.34
21.53
24.15
14.13
17.61
38.91
49.28
0.14
29.25
31.26
20.83
5.89
1a
1b
1c
2a
2b
2c
3a
3b
3c
4a
4b
4c
5a
5b
5c
6a
6b
6c
7a
7b
7c
4.56
9.27
49.90
9.82
4.26
53.54
13.31
26.66
>100
35.24
38.99
20.31
58.48
47.68
14.17
14.96
22.64
14.25
11.00
8.10
6.25
14.79
4.37
5.88
2.78
1.01
3.42
7.29
30.16
>100
16.32
13.49
3.74
6.51
2.74
5.99
10.72
100.00
19.50
21.38
14.79
28.18
12.59
10.96
4.57
>100
42.04
40.79
14.33
>100
16.87
16.64
10.23
22.81
11.23
16.08
39.43
11.49
56.35
>100
5.03
>100
3.99
>100
39.05
11.21
12.28
18.66
6.39
28.57
49.81
52.44
1.31
7.02
4.33
5.13
15.19
4.63
3.72
5.34
7.13
5.25
5.55
2.55
0.38
1.28
5.91
6.83
9.45
7.58
6.97
11.48
11.75
10.72
13.18
15.49
36.31
6.65
15.98
21.81
11.42
51.73
67.63
17.98
11.04
36.77
40.43
38.55
6.51
7.05
5.96
7.59
7.38
7.96
6.33
10.38
47.33
20.16
16.58
aGI50 mean-graph midpoint (MG-MID) = average sensitivity of all cell lines toward the test compounds.

Vol. 21, No. 2, 2010
Savariz et al.
291
Table 2. TGI (in µmol L-1) and LC50 (in µmol L-1, values in parentheses) and TGI and LC50 MG-MID (µmol L-1) for compounds 1a-c and 2-7(a-c)
Compounds
Cancer cell line
Melanoma
UACC-62
Breast
MCF7
Ovarian
resistant
Renal
786-0
Lung
NCI 460
Prostate
PCO-3
Ovarian
OVCAR
Colon
HT29
MG-MIDa
NCI/ADR
Doxorubicin
0.44 (0.99)
>100
0.09 (2.78) 6.14 (68.44) 10.00 (>100) 1.25 (>100) 4.59 (82.12) 2.61 (>100) 10.58 (>100) 2.09 (33.37)
1a
1b
1c
2a
2b
2c
3a
3b
3c
4a
4b
4c
5a
5b
5c
6a
6b
6c
7a
7b
7c
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
35.77(>100)
>100
>100
>100
>100
>100
>100
>100
>100 (>100)
87.1 (>100)
>100 (>100)
>100
>100
15.63 (56.88) 16.01 (74.61) 20.10 (63.05) 3.96 (20.62) 17.63 (61.95) 30.91 (>100) 14.64 (52.41) 81.39 (>100) 18.36 (60.49)
>100
98.35 (>100)
>100
>100
39.16
>100
>100
>100
>100
>100
>100
>100
>100
88.90 (>100)
>100
>100
>100
>100
>100
>100
>100
>100
>100
67.50 (>100)
95.97 (>100)
25.59 (>100)
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
93.62 (>100)
63.25 (>100)
60.05 (93.62)
>100 (>100)
77.03 (>100)
86.77 (92.17)
94.86 (92.17)
87.74 (>100)
48.36 (92.29)
51.91 (89.49)
70.94 (>100)
6.81 (>100)
15.12 (58.99)
>100
>100
43.71 (>100)
>100
>100
>100
>100
57.49 (>100)
32.14 (52.07)
65.59 (48.62)
35.12 (>100)
>100
21.55 (>100)
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
91.16 (>100) 66.96 (>100) 37.97 (>100) 12.94 (52.62) 39.85 (>100) 72.49 (>100) 34.54 (>100)
53.52 (>100) 68.48 (>100) 52.52 (>100) 21.66 (41.14)
>100
>100
>100
>100
56.83 (>100) 22.25 (>100)
>100 58.91 (>100)
58.52 (>100)
34.17 (>100)
21.31 (47.18)
25.34 (52.70)
26.24 (53.19)
>100
>100
>100
>100
>100
>100
>100
>100
94.87 (>100) 19.62 (>100)
51.40 (>100)
46.48 (>100)
>100
>100
72.79 (>100) 27.24 (57.73) 75.33 (>100) 63.44 (93.36)
>100 21.53 (49.91) 91.41 (>100) 61.13 (83.18)
91.37 (>100) 77.82 (>100) 71.19 (>100) 60.35 (>100) 24.81 (>100) 65.45 (>100) 57.86 (93.33)
>100
>100
>100
37.81 (>100)
>100
>100
46.84 (>100) 30.11(>100) 44.97(69.85) 57.36 (>100) 66.09 (95.61)
>100 >100 >100 >100 >100 (>100)
63.76 (>100) 28.81 (56.37) 71.36 (>100) 58.11 (86.02)
>100
>100
aTGI and LC50 mean-graph midpoint (MG-MID) = average sensitivity of all cell lines toward the test compounds.
improved antitumoral activity 4.5 timefold compared to
those of the 1,3,4-oxadiazoles 1a and 1c. Also, concerning
to the effect of the different alkylamino groups on activity
we observed that the isopropylamino(methyl) and
benzylamino(methyl) substituents were the best choice for
an increase of activity.
towards the bacteria B. subtilis (MIC = 250 mg mL-1).
For the Mannich bases 2-7(a-c) none of the derivatives
presented activity at the maximum concentration tested
(250 mg mL-1), which demonstrated that the introduction of
alkylamino(methyl) groups at the oxadiazole ring of 1a-c
did not contribute for antimicrobial activity.
Antimicrobial activity
In silico study
Compounds 1a-c and their Mannich bases 2-7(a-c) were
assayed against the bacteria Bacillus subtilis ATCC 2576,
Escherichia coli ATCC 25922, Pseudomonas aeruginosa
ATCC 13388, Sthaphylococus aureus ATCC 6538; and
against the fungi Candida albicans ATCC 10231, Candida
parapsilosis ATCC-22019 and Candida tropicalis ATCC-
28707.
The bioassays results for compounds 1a-c showed a
potent antifungal activity for compound 1b against the
Candida albicans fungi, with MIC value of 3.1 mg mL-1
This derivative and the compound 1a were weakly active
An in silico computational study of the synthesized
1-phenyl substituted-3-(3-alkylaminomethyl-2-thioxo-1,3,4-
oxadiazol-5-yl) b-carbolines 2-7(a-c) was performed by
determination of Lipinski’s parameters, topological polar
surface area (TPSA) and percentage of absorption (%ABS).
Calculations were performed using “Molinspiration online
property calculation toolkit” (http://www.molinspiration.
com)20 and “OSIRIS property explorer” (www.organic-
chemistry.org/prog/peo).21The percentage of absorption was
estimated using equation: %ABS = 109 - 0.345 × TPSA,
according to Zhao et al.19 These data are shown in Table 3.

292
Synthesis, Antitumor and Antimicrobial Activity
J. Braz. Chem. Soc.
Table 3. Lipinsk´s parameters and %ABS, TPSA, Log S for compounds 2-7 (a-c)
Comp
% ABS
TPSA (Ų)
Lipinski’s parameters
nDLH donors
Log S
nALH acceptors
milogP
4.31
4.27
4.42
5.08
5.04
5.18
5.55
5.50
5.65
5.04
5.00
5.14
4.29
4.25
4.39
3.73
3.69
3.83
MW
n violations
2a
2b
2c
3a
3b
3c
4a
4b
4c
5a
5b
5c
6a
6b
6c
7a
7b
7c
84.27
68.46
83.15
84.27
68.46
83.15
84.27
68.46
83.15
84.27
68.46
83.15
87.3
71.68
117.50
74.91
71.676
117.5
74.914
71.68
117.50
74.91
71.68
117.50
74.91
62.89
108.71
66.13
72.12
117.95
75.36
6
9
7
6
9
7
6
9
7
6
9
7
6
9
7
7
10
8
2
2
2
2
2
2
2
2
2
2
2
2
1
1
1
1
1
1
415.52
460.52
458.59
429.55
474.55
472.62
455.59
500.58
498.66
463.57
508.56
506.64
427.53
472.53
470.60
443.53
488.53
486.60
0
0
0
1
1
1
1
2
1
1
1
2
0
0
0
0
0
0
-6.51
-6.97
-6.55
-6.67
-7.13
-6.71
-7.41
-6.38
-7.44
-7.16
-6.38
-7.19
-6.16
-6.62
-6.19
-5.54
-6.00
-5.57
71.49
86.19
84.12
68.31
83.00
In vivo absorption of the new synthesized derivatives
was tentatively assessed by means of theoretical calculations
following Lipinski’s rule of five, which establishes that
the absorption or permeation of an orally administered
compound is more likely to be good if the drug satisfies
the following criteria: (i) hydrogen bond donors ≤ 5
(OH and NH groups); (ii) hydrogen bond acceptors ≤ 10
(N and O atoms); (iii) molecular weight < 500; (iv)
calculated log P < 5.18-20 Compounds violating more than
one of these rules may present bioavailability problems.
Our results (Table 3) revealed that the Mannich base
derivatives containing the isopropylamino(methyl) (2a-c),
pyrrolidyl(methyl) (6a-c) and morpholyl(methyl) (7a-c)
groups attached to the 1,3,4-oxadiazole ring presented
lipophilicity minor than 5, with values between 3.69 and
4.41. On the other hand, the derivatives containing the
butylamino(methyl) (3a-c), cyclohexylamino(methyl)
(4a-c) and benzylamino(methyl) (5a-c) groups showed
lipophilicity larger than 5.0, violating one of the Lipinski’s
rules.
of all derivatives ranged between 68.31 and 87.30 %,
indicating that these compounds have a good permeability
in the cellular plasmatic membrane. In summary, in silico
study pointed the Mannich bases synthesized in our work
as potential candidates for new antitumor agents.
Conclusions
In conclusion, several 1-substituted phenyl-b-carbolines
containing a 3-alkylamino(methyl)-2-thioxo-1,3,4-
oxadiazolyl group were prepared and identified as novel
antitumor agents. Compounds 2a, 2c and 5c were the most
active derivatives, exhibiting a broad spectrum antitumor
activity at GI50 and TGI levels. Except for 3b, 4c and 7c,
the Mannich base derivatives displayed higher anticancer
activity than their corresponding precursors. For the most
active Mannich bases 2a, 2c and 5c, the introduction of an
alkylamino(methyl) group at N-3 of the heterocyclic ring
improved antitumor activity 4.5 timefold compared to those
of the 1,3,4-oxadiazoles 1a and 1c.
Except for 4b, 5b e 5c the molecular weight were minor
than 500 (415.52 > MW < 498.65). All Mannich base
derivatives have number of hydrogen bond acceptors (n-
ON = 6-10) and donors (n-OHNH = 1-2) in agreement with
Lipinski’s rule. The calculated percent absorption (%ABS)
The antimicrobial bioassays results showed that, among
all tested compounds, only compound 1b was active,
displaying potent activity against the yeast C. albicans.
Finally, in silico study pointed the novel derivatives as
potential candidates for new drugs.

Vol. 21, No. 2, 2010
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293
Experimental
1-(3-Nitrophenyl)-3-[3-isopropylamino(methyl)-2-thioxo-
1,3,4-oxadiazol-5-yl] b-carboline (2b)
o
General
Yield: 89%, mp 236.0- 237.0 C. IR (KBr) nmax/cm-1:
3054 (N–H), 1611 (C=N), 1350 and 1239 (C=S), 1566,
1485 and 1465 (C=C). 1H NMR (300 MHz, DMSO-d6): d
9.01 (s, 1H, H-4), 8.55 (d, J 7.8 Hz, 1H, H-5), 7.37 (t, J 7.8
Hz, 1H, H-6), 7.63-7.73 (m, 2H, H-7, H-8), 12.17 (s, 1H,
9-NH), 8.83 (s, 1H, H-2’), 8.51 (d, J 7.8 Hz, H-4’), 7.97
(t, J 7.8 Hz, H-5’), 8.44 (dd, J 7.8 Hz, 1.8 Hz, H-6’), 6.00
(brs, 2H, CH2-exocyclic), 11.46 (brs, 1H, NH-isopropyl),
4.63 (hep, J 6.9 Hz, 1H, CH-isopropyl), 1.23 (d, J 6.9 Hz,
6H, CH3-isopropyl). 13C NMR (75.5 MHz, DMSO-d6): d
141.7 (C-1), 137.9 (C-3), 116.7 (C-4), 130.5 (C-4a), 121.0
(C-4b), 122.4 (C-5), 120.7 (C-6), 129.2 (C-7), 112.7 (C-8),
139.09 (C-8a), 139.0 (C-9a), 134.1 (C-1’), 123.3 (C-2’),
148.3 (C-3’), 123.6 (C-4’), 130.5 (C-5’), 134.9 (C-6’),
174.3 (C-2”), 159.9 (C-5”), 64.6 (CH2-exocyclic), 46.2
(CH-isopropyl), 18.9 (CH3-isopropyl). EIMS, 70 eV, m/z
(rel. int., %): 460 (5, M+·), 344 (15), 289 (95), 242 (100),
121(30), 100 (75).
1Hand13CspectrawererecordedinaVarianspectrometer
model Mercury plus BB at 300 MHz and 75.5 MHz,
respectively, with DMSO-d6 as solvent and TMS as the
internal standard. Mass spectra (MS) were recorded in a
Thermoelectron Corporation Focus-DSQ II spectrometer.
IR spectra were recorded on a BOMEM spectrometer
model MB-100. For TLC, Merck precoated plates
(silica gel 60 G254) were used. Silica gel 60 Merck
(230-400 mesh) was used in column chromatography
purification of some compounds. All reagents were
purchased from commercial suppliers.
Generalprocedureforpreparationof1-(substitutedphenyl)-
3-[2-thioxo-3-alkylamino(methyl)-1,3,4-oxadiazol-5-yl]
b-carbolines 2-7(a-c)
The 1-(substituted phenyl)-3-(2-thioxo-1,3,4-oxadiazol-
5-yl) b-carbolines 1a-c were prepared as previously
reported.14
1-(4-N,N-Dimethylaminophenyl)-3-[3-isopropylamino
(methyl)-2-thioxo-1,3,4-oxadiazol-5-yl] b-carboline (2c)
o
To a solution of derivatives 1a-c (0.5 mmol) in ethanol
(10 mL) the primary or secondary amines (0.5 mmol) were
added, followed of the dropwise addition of formaldehyde
(37%, 3.0 mmol). The solution was stirred for 24 h at 60 oC
and then, for 1h at 0 oC. The precipitated solid was filtered
under vacuum suction and washed with cold ethanol. The
characterization data of the Mannich bases obtained are
given bellow.
Yield: 90%, mp 160.0-161.0 C. IR (KBr) nmax/ cm-1:
3085 (N–H), 1609 (C=N), 1365 and 1240 (C=S), 1557,
1
1488 and 1466 (C=C). H NMR (300 MHz, DMSO-d6):
d 8.82 (s, 1H, H-4), 8.42 (d, J 7.8 Hz, 1H, H-5), 7.32 (t,
J 7.8 Hz, H-6), 7.60 (t, J 7.8 Hz, H-7), 7.72 (d, J 7.8 Hz,
H-8), 11.87 (s, 1H, 9-NH), 7.95 (d, J 8.7 Hz, 2H, H-2’and
H-6’), 6.96 (d, J 8.7 Hz, 2H, H-3’ and H-5’), 3.05 (s, 6H,
N(CH3)2), 5.98 (brs, 2H, CH2- exocyclic), 11.40 (brs, 1H,
NH-isopropyl), 4.61 (hep, J 6.6 Hz, 1H, CH-isopropyl),
1.24 (d, J 6.6 Hz, 6H, CH3-isopropyl). 13C NMR (75.5
MHz, DMSO-d6): d 141.5 (C-1), 138.7 (C-3), 114.7 (C-
4), 124.9 (C-4a), 121.2 (C-4b), 122.0 (C-5), 120.3 (C-6),
128.6 (C-7), 112.8 (C-8), 141.3 (C-8a), 133.5 (C-9a), 129.4
(C-1’), 129.3 (C-2’), 112.2 (C-3’), 150.8 (C-4’), 112.2
(C-5’), 129.3 (C-6’), 40.0 - N(CH3)2, 174.3 (C-2”), 166.7
(C-5”), 64.6 (CH2-exocyclic), 46.2 (CH-isopropyl), 19.0
(CH3-isopropyl). EIMS, 70 eV, m/z (rel. int., %): 458 (5,
M+·), 344 (10), 287 (100), 242 (45), 121 (25), 100 (45).
1-Phenyl-3-[3-isopropylamino(methyl)-2-thioxo-1,3,4-
oxadiazol-5-yl] b-carboline (2a)
o
Yield: 62%, mp 234.0-237.0 C. IR (KBr) nmax /cm-1:
3040 (N–H), 1614 (C=N), 1360 and 1239 (C=S), 1565,
1
1487 and 1464 (C=C). H NMR (300 MHz, DMSO-d6):
d 8.94 (s, 1H, H-4), 8.47 (d, J 7.8 Hz, 1H, H-5), 7.35 (t, J
7.8 Hz, 1H, H-6), 7.57-7.73 (m, 5H, H-7, H-8, H-3’, H-4’
and H-5’), 12.00 (s, 1H, NH-9), 8.09 (d, J 6.9 Hz, 2H, H-2’
and H-6’), 5.99 (brs, 2H, CH2-exocyclic), 11.43 (brs, 1H,
NH-isopropyl), 4.60 (hep, J 6.9 Hz, 1H, CH-isopropyl),
1.22 (d, J 6.9 Hz, 6H, CH3-isopropyl). 13C NMR (75.5 MHz,
DMSO-d6): d 141.06 (C-1), 138.9 (C-3), 115.9 (C-4), 128.8
(C-4a), 121.1 (C-4b), 122.2 (C-5), 120.5 (C-6), 129.2 (C-
7), 112.8 (C-8), 140.4 (C-8a), 133.9 (C-9a), 129.9 (C-1’),
128.5 (C-2’/6’), 129.0 (C-3’/5’), 128.9 (C-4’), 174.3 (C-2”),
159.7 (C-5”), 64.6 (CH2-exocyclic), 46.2 (CH-isopropyl),
18.9 (CH3-isopropyl). EIMS, 70 eV, m/z (rel. int., %):
415 (10, M+·), 344 (10), 271 (20), 243 (100), 121 (5),
100 (5).
1-Phenyl-3-[3-butylamino(methyl)-2-thioxo-1,3,4-
oxadiazol-5-yl]b-carboline (3a)
o
Yield: 83%, mp 212.0-215.0 C. IR (KBr) nmax/cm-1:
3057 (N–H), 1618 (C=N), 1394 and 1238 (C=S), 1566,
1
1492 and 1456 (C=C). H NMR (300 MHz, DMSO-d6):
d 8.93 (s, 1H, H-4), 8.46 (d, J 7.8 Hz, 1H, H-5), 7.35 (t, J
7.8 Hz, 1H, H-6), 7.57-7.73 (m, 5H, H-7, H-8, H-3’, H-4’
and H-5’), 11.99 (s, 1H, 9-NH), 8.08 (d, J 6.9 Hz, 2H, H-2’
and H-6’), 5.92 (brs, 2H, CH2-exocyclic), 11.44 (brs, 1H,

294
Synthesis, Antitumor and Antimicrobial Activity
J. Braz. Chem. Soc.
NH-butyl), 3.58 (t, J 7.2 Hz, 2H, CH2-butyl), 1.56 (quint.,
J 7.2 Hz, 2H, CH2-butyl), 1.31 (sext., J 7.2 Hz, 2H, CH2-
butyl), 0.90 (t, J 7.2 Hz, 3H, CH3-butyl). 13C NMR (75.5
MHz, DMSO-d6): d 141.6 (C-1), 138.9 (C-3), 115.9 (C-
4), 129.9 (C-4a), 121.1 (C-4b), 122.2 (C-5), 120.4 (C-6),
129.2 (C-7), 112.8 (C-8), 140.5 (C-8a), 137.5 (C-9a), 133.9
(C-1’), 128.5 (C-2’/6’), 129.0 (C-3’/5’), 128.9 (C-4’),
175.5 (C-2”), 160.5 (C-5”), 68.0 (CH2-exocyclic), 43.9
(CH2-butyl), 28.4 (CH2- butyl), 19.4 (CH2- butyl), 13.6
(CH3-butyl). EIMS, 70 eV, m/z (rel. int., %): 429 (5, M+·),
344 (25), 243 (100), 157 (15), 102 (15).
(C-3’), 150.8 (C-4’), 112.2 -(C-5’), 129.3 (C-6’), 175.5
(C-2”), 164.6 (C-5”), 40.0 - (CH3)2, 68.2 (CH2-exocyclic),
44.0 (CH2-butyl), 28.5 (CH2-butyl), 19.5 (CH2-butyl), 13.7
(CH3-butyl). EIMS, 70 eV, m/z (rel. int., %): 472 (5, M+·),
242 (25), 157 (70), 84 (25), 76 (100).
1-Phenyl-3-[3-cyclohexylamino(methyl)-2-thioxo-1,3,4-
oxadiazol-5-yl] b-carboline (4a)
o
Yield: 74%, mp 222.0-224.0 C. IR (KBr) nmax/ cm-1:
3042 (N–H), 1613 (C=N), 1372 and 1237 (C=S), 1564,
1484 and 1453(C=C). 1H NMR (300 MHz, DMSO-d6): d
8.94 (s, 1H, H-4), 8.45 (d, J 7.8 Hz, 1H, H-5), 7.35 (t, J 7.8
Hz, 1H, H-6), 7.58 - 7.73 (m, 5H, H-7, H-8, H-3’, H-4’and
H-5’), 12.00 (s, 1H, 9-NH), 8.10 (d, J 6.9 Hz, 2H, H-2’and
H-6’), 6.00 (brs, 2H, CH2-exocyclic), 11.40 (brs, 1H, NH-
cyclohexyl), 4.21 (m, 1H, CH-cyclohexyl), 1.03-1.84 (m,
10H, CH2-cyclohexyl). 13C NMR (75.5 MHz, DMSO-d6): d
141.6 (C-1), 138.9 (C-3), 115.8 (C-4), 128.7 (C-4a), 121.1
(C-4b), 122.2 (C-5), 120.4 (C-6), 129.2 (C-7), 112.8 (C-8),
140.3 (C-8a), 133.8 (C-9a), 130.0 (C-1’), 128.5 (C-2’/6’),
128.9 (C-3’/5’), 128.8 (C-4’), 177.6 (C-2”), 166.8 (C-5”),
65.3 (CH2-exocyclic), 53.7 (CH-cyclohexyl), 29.1 (CH2-
cyclohexyl), 25.0 (CH2-cyclohexyl). EIMS, 70 eV, m/z (rel.
int., %): 455 (5, M+·), 243 (100), 183 (10), 102 (25), 55 (30).
1-(3-Nitrophenyl)-3-[3-butylamino(methyl)-2-thioxo-1,3,4-
oxadiazol-5-yl] b-carboline (3b)
o
Yield: 65%, mp 230.0-235.0 C. IR (KBr) nmax /cm-1:
3053 (N–H), 1612 (C=N), 1345 and 1238 (C=S), 1565 and
1
1454 (C=C). H NMR (300 MHz, DMSO-d6): d 9.00 (s,
1H, H-4); 8.55 (d, J 7.8 Hz,1H, H-5), 7.37 (t, J 7.8 Hz, 1H,
H-6), 7.63 - 7.73 (m, 2H, H-7, H-8), 12.17 (s, 1H, 9-NH),
8.83 (s, 1H, H-2’), 8.50 (d, J 8.0 Hz, 1H, H-4’), 7.96 (t, J
8.0 Hz, 1H, H-5’), 8.43 (dd, J 8.0 and 2.1 Hz, 1H, H-6’),
5.98 (brs, 2H, CH2-exocyclic), 11.47 (brs, 1H, NH-butyl),
3.59 (t, J 7.2 Hz, 2H, CH2-butyl), 1.59 (quint., J 7.2 Hz, 2H,
CH2-butyl), 1.31 (sext., J 7.2 Hz, 2H, CH2-butyl), 0.90 (t, J
7.2 Hz, 3H, CH3-butyl). 13C NMR (75.5 MHz, DMSO-d6):
d 141.7 (C-1), 138.9 (C-3), 116.7 (C-4), 121.0 (C0-4b),
123.6 (C-5), 120.7 (C-6), 129.2 (C-7), 112.7 (C-8), 139.1
(C-8a), 137.8 (C-9a), 134.1 (C-1’), 123.4 (C-2’), 148.3 (C-
3’), 122.4 (C-4’), 130.5 (C-5’), 134.8 (C-6’), 175.4 (C-2”),
158.5 (C-5”), 68.5 (CH2-exocyclic), 44.1 (CH2-butyl), 28.3
(CH2-butyl), 19.5 (CH2-butyl), 13.6 (CH3-butyl). EIMS,
70 eV, m/z (rel. int., %): 474 (5, M+·), 242 (15), 157 (95),
102 (75), 57 (100).
1-(3-Nitrophenyl)-3-[3-cyclohexylamino(methyl)-2-thioxo-
1,3,4-oxadiazol-5-yl] b-carboline (4b)
o
Yield: 83%, mp 222.0-223.0 C. IR (KBr) nmax/cm-1:
3064 (N–H), 1613 (C=N), 1346 and 1239 (C=S), 1559,
1
1485 and 1459 (C=C). H NMR (300 MHz, DMSO-d6):
d 9.00 (s, 1H, H-4), 8.55 (d, J 7.8 Hz, 1H, H-5), 7.37 (t, J
7.8 Hz, 1H, H-6), 7.63-7.73 (m, 2H, H-7 and H-8), 12.17
(s, 1H, 9-NH), 8.82 (brs, 1H, H-2’), 8.50 (d, J 8.1 Hz, 1H,
H-4’), 7.97 (t, J 8.1 Hz, 1H, H-5’), 8.44 (d, J 8.1 Hz,1H,
H-6’), 6.02 (brs, 2H, CH2-exocyclic), 11.46 (brs, 1H, NH-
cyclohexyl-), 4.22 (m, 1H, CH-cyclohexyl), 1.03-1.85 (m,
10H, CH2-cyclohexyl). 13C NMR (75.5 MHz, DMSO-d6): d
141.7 (C-1), 139.1 (C-3), 116.7 (C-4), 121.0 (C-4b), 122.4
(C-5), 120.6 (C-6), 129.2 (C-7), 112.7 (C-8), 139.7 (C-8a),
137.9 (C-9a), 134.1 (C-1’), 123.4 (C-2’), 148.4 (C-3’),
123.6 (C-4’), 130.5 (C-5’), 134.9 (C-6’), 174.2 (C-2”),
164.9 (C-5”), 65.4 (CH2-exocyclic), 53.8 (CH-cyclohexyl),
28.9 (CH2-cyclohexyl), 24.9 (CH2-cyclohexyl), 25.1 (CH2-
cyclohexyl), 24.6 (CH2-cyclohexyl). EIMS, 70 eV, m/z (rel.
int., %): 500 (5,M+·), 242 (60), 183 (30), 102 (100), 55 (90).
1-(4-N,N-Dimethylaminophenyl)-3-[3-butylamino(methyl)-
2-thioxo-1,3,4-oxadiazol-5-yl] b-carboline (3c)
Yield: 92%, mp 214.0-216 oC. IR (KBr) nmax/cm-1: 3262
(N-H); 1608 (C=N); 1348 and 1229 (C=S), 1558, 1493 and
1
1452 (C=C). H NMR (300 MHz, DMSO-d6): d 8.80 (s,
1H, H-4), 8.42 (d, J 7.8 Hz, 1H, H-5), 7.32 (t, J 7.8 Hz, 1H,
H-6), 7.60 (t, J 7.8 Hz, 1H, H-7), 7.71 (d, J 7.8 Hz, 1H, H-8),
11.86 (s, 1H, 9-NH), 7.95 (d, J 8.7 Hz, 1H, H-2’), 6.96 (d,
J 8.7 Hz, 1H, H-3’), 6.96 (d, J 8.7 Hz, 1H, H-5’), 7.95 (d,
J 8.7 Hz, 1H, H-6’), 3.05 (s, 6H, N(CH3)2), 5.92 (brs, 2H,
CH2-exocyclic), 11.41 (brs, 1H, NH-butyl), 3.59 (t, J 7.3
Hz, 2H, CH2-butyl), 1.57 (quint., J 7.3 Hz, 2H, CH2-butyl),
1.32 (sext., J 7.3 Hz, 2H, CH2-butyl), 0.92 (t, J 7.3 Hz, 3H,
CH3-butyl). 13C NMR (75.5 MHz, DMSO-d6): d 141.4 (C-
1), 138.7 (C-3), 114.7 (C-4), 124.9 (C-4a), 121.2 (C-4b),
122.0 (C-5), 120.3 (C-6), 128.6 (C-7), 112.8 (C-8), 141.3
(C-8a), 129.3 (C-9a), 133.5 (C-1’), 129.3 (C-2’), 112.2
1-(4-N,N-Dimethylaminophenyl-3-[3-cyclohexylamino
(methyl)-2-thioxo-1,3,4-oxadiazol-5-yl] b-carboline (4c)
o
Yield: 70%, mp 173.0-175.0 C. IR (KBr) nmax/cm-1:
3083 (N–H), 1609 (C=N), 1361 and 1240 (C=S), 1555,
1
1489 and 1450 (C=C). H NMR (300 MHz, DMSO-d6):

Vol. 21, No. 2, 2010
Savariz et al.
295
d 8.81 (s, 1H, H-4), 8.42 (d, J 7.8 Hz, 1H, H-5), 7.32 (t,
J 7.8 Hz, 1H, H-6), 7.60 (t, J 7.8 Hz, 1H, H-7), 7.71 (d,
J 9.0 Hz, 1H, H-8), 11.88 (s, 1H, 9 -NH), 7.97 (d, J 9.0
Hz, 1H, H-2’), 6.96 (d, J 9.0 Hz, 1H, H-3’), 6.96 (d, J
9.0 Hz, 1H, H-5’), 7.97 (d, J 9.0 Hz, 1H, H-6’), 3.05 (s,
6H, N(CH3)2), 5.99 (brs, 2H, CH2-exocyclic), 11.41 (brs,
1H, NH-cyclohexyl), 4.21 (m, 1H, CH-cyclohexyl), 1.03-
1.84 (m, 10H, CH2-cyclohexyl). 13C NMR (75.5 MHz,
DMSO-d6): d 141.4 (C-1), 138.7 (C-3), 114.6 (C-4), 124.9
(C-4a), 121.2 (C-4b), 122.0 (C-5), 120.3 (C-6), 128.5 (C-
7), 112.7 (C-8), 141.2 (C-8a), 133.4 (C-9a), 129.4 (C-1’),
129.3 (C-2’), 112.1 (C-3’), 150.8 (C-4’), 112.1 (C-5’),
129.3 (C-6’), 174.2 (C-2”), 39.9 -N(CH3)2, 65.4 (CH2-
exocyclic), 53.7 (CH-cyclohexyl), 29.1 (CH2-cyclohexyl),
25.0 (CH2-cyclohexyl). EIMS, 70 eV, m/z (rel. int., %): 498
(5, M+·), 183 (5), 83 (55), 57 (100).
122.4 (C-5), 120.7 (C-6), 129.2 (C-7), 112.6 (C-8), 141.6
(C-8a), 134.8 (C-9a), 134.1 (C-1’), 123.2 (C-2’), 148.2 (C-
3’), 123.6 (C-4’), 130.4 (C-5’), 135.4 (C-6’), 176.4 (C-2”),
160.2 (C-5”), 67.8 (CH2-exocyclic), 47.7 (CH2-benzyl),
137.9 (C-benzyl), 128.0 (CH-benzyl), 128.6 (CH-benzyl),
127.8 (CH-benzyl). EIMS, 70 eV, m/z (rel. int., %): 509 (5,
M+·), 191 (10), 91 (100), 65 (15).
1-(4-N,N-Dimethylaminophenyl)-3-[3-benzylamino
(methyl)-2-thioxo-1,3,4-oxadiazol-5-yl] b-carboline (5c)
o
Yield: 86%, mp 200.0-205.0 C. IR (KBr) nmax/cm-1:
3086 (N–H), 1607 (C=N), 1363 and 1241 (C=S), 1558,
1
1495 and 1443 (C=C). H NMR (300 MHz, DMSO-d6):
d 8.79 (s, 1H, H-4), 8.40 (d, J 7.8 Hz, 1H, H-5), 7.28-7.39
(m, 1H, H-6), 7.59 (t, J 7.8 Hz, 1H, H-7), 7.68-7.76 (m, 3H,
H-8, H-2’and H-6’), 11.84 (s, 1H, 9-NH), 6.86 (d, J 8.4 Hz,
2H, H-3’ and H-5’), 3.06 (s, 6H, N(CH3)2), 5.80 (brs, 2H,
CH2-exocyclic), 4.86 (s, 2H, CH2-benzyl), 7.43 (d, J 4.5 Hz,
CH-benzyl), 7.28-7.39 (m, 3H, CH-benzyl). 13C NMR (75.5
MHz, DMSO-d6): d 141.4 (C-1), 135.4 (C-3), 114.7 (C-4),
124.8 (C-4a), 121.2 (C-4b), 122.0 (C-5), 120.3 (C-6), 128.5
(C-7), 112.8 (C-8), 141.1 (C-8a), 133.4 (C-9a), 129.3 (C-1’),
129.1 (C- 2’/6’), 112.1 (C-3’/5’), 150.7 (C-4’), 175.1 (C-2”),
160.1 (C-5”), 40.0 -N(CH3)2, 67.8 (CH2-exocyclic), 47.8
(CH2-benzyl), 138.4 (C-benzyl), 128.8 (CH-benzyl), 128.2
(CH-benzyl), 127.9 (CH-benzyl). EIMS, 70 eV, m/z (rel. int.,
%): 506 (5, M+·), 242 (45), 191 (35), 91 (100).
1-Phenyl-3-[3-benzylamino(methyl)-2-thioxo-1,3,4-
oxadiazol-5-yl] b-carboline (5a)
o
Yield: 79%, mp 225.0-228.0 C. IR (KBr) nmax /cm-1:
3062 (N–H), 1618 (C=N), 1396 and 1237 (C=S), 1565,
1493, and 1454 (C=C). 1H NMR (300 MHz, DMSO-d6):
d 8.91 (s, 1H, H-4), 8.45 (d, J 7.8 Hz, 1H, H-5), 7.31-7.38
(m, 1H, H-6), 7.60-7.64 (m, 1H, H-7), 7.70 (d, J 7.8 Hz,
1H, H-8), 11.96 (brs, 1H, 9-NH), 7.89 (d, J 6.9 Hz, 2H,
H-2’ and H-6’), 7.60 - 7.64 (m, 3H, H-3’, H-4’ and H-5’),
5.78 (brs, 2H, CH2-exocyclic), 11.74 (brs, 1H, NH-benzyl),
4.85 (s, 2H, CH2-benzyl), 7.31-7.38 (m, 3H, CH-benzyl),
7.42 (d, J 3.6 Hz, 2H, CH-benzyl). 13C NMR (75.5 MHz,
DMSO-d6): d 141.6 (C-1), 138.6 (C-3), 115.9 (C-4), 129.9
(C-4a), 121.0 (C-4b), 122.2 (C-5), 120.4 (C-6), 129.1 (C-
7), 112.7 (C-8), 140.4 (C-8a), 137.4 (C-9a), 133.9 (C-1’),
128.4 (C-2’/6’), 129.0 (C-3’/5’), 128.9 (C-4’), 175.1 (C-2”),
160.1 (C-5”), 67.7 (CH2-exocyclic), 47.7 (CH2-benzyl),
135.4 (C-benzyl), 128.2 (CH-benzyl), 128.8 (CH-benzyl),
128.0 (CH-benzyl). EIMS, 70 eV, m/z (rel. int., %): 463
(10, M+·), 344 (95), 242 (45), 191 (35), 91 (100).
1-Phenyl-3-[3-pyrrolidylamino(methyl)-2-thioxo-1,3,4-
oxadiazol-5-yl] b-carboline (6a)
o
Yield: 55%, mp 207.0-209.0 C. IR (KBr) nmax/cm-1:
3280 (N-H), 1622 (C=N), 1374 and 1243 (C=S), 1567,
1
1496, 1445 and 1415 (C=C). H NMR (300 MHz,
DMSO-d6): d 8.87 (s, 1H, H-4), 8.50 (d, J 7.8 Hz, 1H,
H-5), 7.35 (t, J 7.8 Hz, 1H, H-6), 7.57 - 7.72 (m, H-7,
H-8, H-3’, H- 4’ and H-5’), 11.99 (brs, 1H, 9-NH), 8.05
(d, J 6.9 Hz, 2H, H-2’ and H-6’), 5.20 (brs, 2H, CH2-
exocyclic), 2.89 (brs, 4H, CH2-pyrrolidyl), 1.71 (brs, 4H,
CH2-pyrrolidyl).13C NMR (75.5 MHz, DMSO-d6): d 142.8
(C-1), 137.2 (C-3), 113.9 (C-4), 120.9 (C-4b), 122.4 (C-5),
120.5 (C-6), 129.5 (C-7), 112.8 (C-8), 141.6 (C-8a), 134.0
(C-9a), 131.1 (C-1’), 128.6 (C-2’/6’), 128.9 (C-3’/5’),
129.2 (C-4’), 177.8 (C-2”), 159.5 (C-5”), 66.1 (CH2-
exocyclic), 49.5 (CH2-pyrrolidyl), 23.6 (CH2-pyrrolidyl).
EIMS, 70 eV, m/z (rel. int., %): 427 (5, M+·), 243 (100),
189 (10), 121 (40).
1-(3-Nitrophenyl)-3-[3-benzylamino(methyl)-2-thioxo-
1,3,4-oxadiazol-5-yl] b-carboline (5b)
o
Yield: 77%, mp 216.0-220.0 C. IR (KBr) nmax/cm-1:
3063 (N–H), 1621 (C=N), 1348 and 1240 (C=S), 1566,
1496 and 1454 (C=C). 1H NMR (300 MHz, DMSO-d6): d
8.98 (s, 1H, H-4), 8.48 (d, J 7.5 Hz, 1H, H-5), 7.30-7.40
(m, 1H, H-6), 7.62 - 7.71 (m, 2H, H-7 and H-8), 12.14 (s,
1H, 9-NH), 8.71 (brs, 1H, H-2’), 8.43 (dd, J 7.2 and 1.8 Hz,
1H, H-4’), 7.91 (t, J 7.2 Hz, 1H, H-5’), 8.32 (d, J 7.2 Hz,
1H, H-6’), 5.79 (brs, 2H, CH2-exocyclic), 11.78 (brs, 1H,
NH-benzyl), 4.82 (s, 2H, CH2-benzyl), 7.29-7.40 (m, 5H,
CH-benzyl). 13C NMR (75.5 MHz, DMSO-d6): d 142.1 (C-
1), 138.8 (C-3), 116.7 (C- 4), 127.8 (C-4a), 121.0 (C-4b),
1-(3-Nitrophenyl)-3-[3-pyrrolidylamino(methyl)-2-thioxo-
1,3,4-oxadiazol-5-yl] b-carboline (6b)
o
Yield: 52%, mp 112.0-114.0 C. IR (KBr) nmax/cm-1:
3285 (N-H), 1623 (C=N), 1347 and 1252 (C=S), 1523,

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1498 and 1455 (C=C). H NMR (300 MHz, DMSO-d6):
d 8.95 (s, 1H, H-4), 8.54 (d, J 7.8 Hz, 1H, H-5), 7.37 (t, J
7.8 Hz, 1H, H-6), 7.63-7.72 (m, 2H, H-7 and H-8), 12.17
(s, 1H, 9-NH), 8.80 (s, 1H, H-2’), 8.50 (d, J 7.8 Hz, 1H,
H-4’), 7.96 (t, J 7.8 Hz, 1H, H-5’), 8.44 (d, J 7.8 Hz, 1H,
H-6’), 5.20 (brs, 2H, CH2-exocyclic), 2.89 (brs, 4H, CH2-
pyrrolidyl), 1.71 (brs, 4H, CH2-pyrrolidyl). 13C NMR (75.5
MHz, DMSO-d6): d 141.7 (C-1), 138.6 (C-3), 130.1 (C-4),
120.9 (C-4b), 122.5 (C-5), 120.7 (C-6), 129.3 (C-7), 112.7
(C-8), 140.2 (C-8a), 134.1 (C-9a), 131.4 (C-1’), 123.4
(C-2’), 148.2 (C-3’), 123.7 (C-4’), 130.6 (C-5’), 135.1
(C-6’), 177.9 (C-2”),159.3 (C-5”), 66.2 (CH2-exocyclic),
49.5 (CH2-pyrrolidyl), 23.6 (CH2-pyrrolidyl). EIMS, 70 eV,
m/z (rel. int., %): 472 (10, M+·), 289 (70), 188 (10), 121
(25), 70 (100).
128.9 (C-3’/5’), 129.3 (C-4’), 177.6 (C-2”), 161.2 (C-5”),
70.0 (CH2-exocyclic), 50.1 (CH2-morpholyl), 66.4 (CH2-
morpholyl). EIMS, 70 eV, m/z (rel. int., %): 443 (5, M+·),
243 (100), 121 (20), 58 (25).
1-(3-Nitrophenyl)-3-[3-morpholylamino(methyl)-2-thioxo-
1,3,4-oxadiazol-5-yl] b-carboline (7b)
o
Yield: 85%, mp 163.0-167.0 C. IR (KBr) nmax/cm-1:
3226 (N-H), 1626 (C=N), 1351 and 1249 (C=S), 1559,
1497 and 1453 (C=C). 1H NMR (300 MHz, DMSO-d6): d
8.98 (s, 1H, H-4), 8.55 (d, J 7.8 Hz, 1H, H-5), 7.38 (t, J 7.8
Hz, 1H, H-6), 7.64-7.73 (m, 2H, H-7, H-8), 12.21 (s, 1H,
9-NH), 8.80 (s, 1H, H-2’), 8.50 (d, J 7.8 Hz, 1H, H-4’),
7.97 (t, J 7.8 Hz, 1H, H-5’), 8.45 (dd, J 7.8 and 1.8 Hz, 2H,
H-6’), 5.09 (brs, 2H, CH2-exocyclic), 2.81 (brs, 4H, CH2-
morpholyl), 3.61 (brs, CH2-morpholyl). 13C NMR (75.5
MHz, DMSO-d6): d 141.7 (C-1), 148.2 (C-3), 115.0 (C-4),
122.6 (C-5), 120.8 (C-6), 129.4 (C-7), 112.7 (C-8), 140.4
(C-8a), 134.3 (C-9a), 130.1 (C-1’), 123.4 (C-2’), 148.2 (C-
3’), 123.8 (C-4’), 130.6 (C-5’), 135.1 (C-6’), 177.7 (C-2”),
160.6 (C-5”), 70.0 (CH2-exocyclic), 50.1 (CH2-morpholyl),
66.0 (CH2-morpholyl).EIMS, 70 eV, m/z (rel. int., %): 488
(5, M+·), 289 (95), 242 (100), 121 (20), 57 (25).
1-(4-N,N-Dimethylaminophenyl)-3-[3-pyrrolidylamino
(methyl)-2-thioxo-1,3,4-oxadiazol-5-yl] b-carboline (6c)
Yield: 92%, mp 156.0-160.0 C. IR (KBr) nmax/cm-1:
o
3080 (N-H), 1623 (C=N), 1369 and 1243 (C=S), 1557, 1497
and 1455 (C=C). 1H NMR (300 MHz, DMSO-d6): d 8.74
(s, 1H, H-4), 8.46 (d, J 8.1 Hz, 1H, H-5), 7.32 (t, J 8.1 Hz,
1H, H-6), 7.60 (t, J 8.1 Hz, 1H, H-7), 7.71 (d, J 8.1, 1H,
H-8), 11.87 (s, 1H, 9-NH), 7.96 (d, J 9.0 Hz, 1H, H-2’),
6.97 (d, J 9.0 Hz, 1H, H-3’), 6.96 (d, J 9.0 Hz, 1H, H-5’),
7.96 (d, J 9.0 Hz, 1H, H-6’), 3.05 (s, 1H, N(CH3)2), 5.20
(brs, 2H, CH2-exocyclic), 2.89 (brs, 4H, CH2-pyrrolidyl),
1.71 (brs, 4H, CH2-pyrrolidyl). 13C NMR (75.5 MHz,
DMSO-d6): d 143.5 (C-1), 133.5 (C-3), 112.7 (C-4), 124.6
(C-4a), 121.0 (C-4b), 122.1 (C-5), 120.3 (C-6), 128.6 (C-
7), 112.8 (C-8), 141.4 (C-8a), 130.8 (C-9a), 129.0 (C-1’),
129.4 (C-2’), 112.1 (C-3’), 150.9 (C-4’), 112.1 (C-5’),
129.4 (C-6’), 177.6 (C-2”), 163.7 (C-5”), 40.0 -N(CH3)2,
66.1 (CH2-exocyclic), 49.5 (CH2-pyrrolidyl), 23.6 (CH2-
pyrrolidyl). EIMS, 70 eV, m/z (rel. int., %): 470 (10, M+·),
287 (100), 120 (35).
1-(4-N,N-Dimethylaminophenyl)-3-[3-morpholylamino
(methyl)-2-thioxo-1,3,4-oxadiazol-5-yl] b-carboline (7c)
o
Yield: 83%, mp 215.0-217.0 C. IR (KBr) nmax/cm-1:
3261 (N-H), 1609 (C=N), 1364 and 1238 (C=S), 1556,
1495 and 1438 (C=C). 1H NMR (300 MHz, DMSO-d6):
d 8.75 (s, 1H, H-4), 8.46 (d, J 8.1 Hz, 1H, H-5), 7.33 (t,
J 8.1 Hz, 1H, H-6), 7.60 (t, J 8.1 Hz, H-7), 7.72 (d, J 8.1
Hz, 1H, H-8), 11.90 (s, 1H, 9-NH), 7.96 (d, J 8.7 Hz,
1H, H-2’), 6.97 (d, J 8.7 Hz, 1H, H-3’), 6.97 (d, J 8.7
Hz, 1H, H-5’), 7.96 (d, J 8.7 Hz, 1H, H-6’), 3.05 (s, 6H,
N(CH3)2), 5.08 (brs, 2H, CH2-exocyclic), 2.81 (brs, 4H,
CH2-morpholyl), 3.61 (brs, CH2-morpholyl). 13C NMR
(75.5 MHz, DMSO-d6): d 143.6 (C-1), 133.6 (C-3), 112.9
(C-4), 124.5 (C-4a), 121.0 (C-4b), 122.1 (C-5), 120.4
(C-6), 128.6 (C-7), 112.8 (C-8), 141.4 (C-8a), 130.7
(C-9a), 128.9 (C-1’), 129.4 (C-2’), 112.1 (C-3’), 150.9
(C-4’), 112.1 (C-5’), 129.4 (C-6’), 177.6 (C-2”), 161.4
(C-5”), 39.9 - N(CH3)2, 69.9 (CH2-exocyclic), 50.1 (CH2-
morpholyl), 66.0 (CH2-morpholyl). EIMS, 70 eV, m/z
(rel. int., %): 486 (5, M+·), 242 (30), 121 (15), 57 (100).
1-Phenyl-3-[3-morpholylamino(methyl)-2-thioxo-1,3,4-
oxadiazol-5-yl] b-carboline (7a)
Yield: 82%, mp 208.0-210.0 C. IR (KBr) nmax/cm-1:
o
3207 (N-H indol), 1622 (C=N), 1359 and 1248 (C=S),
1561, 1496 and 1455 cm-1 (C=C). H NMR (300 MHz,
1
DMSO-d6): d 8.90 (s, 1H, H-4), 8.52 (d, J 7.8 Hz, 1H,
H-5), 7.35 (t, J 7.8, 1H, H-6), 7.58-7.73 (m, 5H, H-7, H-8,
H-3’, H-4’ and H-5’), 12.03 (s, 1H, 9-NH), 8.05 (d, J 6.9
Hz, 1H, H-2’ and H-6’), 5.08 (brs, 2H, CH2-exocyclic),
2.81 (t, J 4.3 Hz, 4H, CH2-morpholyl), 3.61 (t, J 4.3 Hz,
4H, CH2-morpholyl). 13C NMR (75.5 MHz, DMSO-d6): d
143.0 (C-1), 137.2 (C-3), 114.3 (C-4), 129.0 (C-4a), 120.9
(C-4b), 122.4 (C-5), 120.5 (C-6), 129.5 (C-7), 112.8 (C-8),
141.6 (C-8a), 134.1 (C-9a), 130.6 (C-1’), 128.6 (C-2’/6’),
Anticancer assays
The synthesized compounds were evaluated in vitro
against eight-cell panel lines consisting of melanoma
(UACC-62), breast (MCF7), ovarian resistant (NCI/ADR),
renal (786-0), lung (NCI-460), prostate (PCO-3), ovarian

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297
(OVCAR) and colon (HT-29). The tests were performed by
the colorimetric method with sulforodamine B, according to
NCI standard protocol and doxorubicin was used as positive
control.22 Assays were performed in a 96-well plate using
four concentrations at 10-fold dilutions (0.25 mg mL-1
to 250 mg mL-1) for each test compound. The anticancer
activity was deduced from concentration-response curves
and three concentration response parameters (GI50, TGI and
LC50) were calculated. The GI50 values (growth inhibitory
activity) (Table 1) refer to the drug concentration that
produce 50% reduction of cellular growth when compared
to untreated control cells.23 The TGI (cytostatic activity)
and LC50 (cytotoxic activity) values parameters (Table 2)
refer to the drug concentration for total growth inhibition
and for killing 50% of cells, respectively. Compounds
with GI50 values < 100 mmol L-1 were considered active. A
mean graph midpoint values (MG-MID) of the compounds
toward tumor cell lines were calculated for each of the
parameters GI50, TGI and LC50. MG-MID values supplied
an averaged activity parameter for all cell lines.23
Acknowledgments
This work was supported by Conselho Nacional
de Desenvolvimento Científico e Tecnológico (CNPq,
Brazil) and Fundação de Amparo a Pesquisa de São Paulo
(FAPESP). We thank CAPES and CNPq for fellowships
(FCS, ASNF, VAB, JEC and MAF).
Supplementary Information
Supplementary information is available free of charge
at http://jbcs.sbq.org.br, as PDF file.
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Web Release Date: November 19, 2009
FAPESP helped in meeting the publication costs of this article.

J. Braz. Chem. Soc., Vol. 21, No. 2, S1-S29, 2010.
Printed in Brazil - ©2010 Sociedade Brasileira de Química
0103 - 5053 $6.00+0.00
Synthesis, Antitumor and Antimicrobial Activity of Novel 1-Substituted
Phenyl-3-[3-alkylamino(methyl)-2-thioxo-1,3,4-oxadiazol-5-yl] b-Carboline Derivatives
Franciele C. Savariz,a Anelise S. N. Formagio,a Valéria A. Barbosa,a
Mary Ann Foglio,b João E. de Carvalho,b Marta C. T. Duarte,b
Benedito P. Dias Filhoc and Maria Helena Sarragiotto*,a
aDepartamento de Química and cDepartamento de Análises Clínicas,
Universidade Estadual de Maringá, 87020-900 Maringá-PR, Brazil
bCentro Pluridisciplinar de Pesquisas Químicas, Biológicas e Agrícolas,
Universidade Estadual de Campinas, CP 6171, 13083-970 Campinas-SP, Brazil
Figure S1. 1H NMR spectra (300 MHz, DMSO-d6) of compound 1a.
*e-mail: mhsarragiotto@uem.br

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Figure S2. 13C NMR / DEPT spectra (75.5 MHz, DMSO-d6) of compound 1a.
Figure S3. 1H NMR spectra (300 MHz, DMSO-d6) of compound 1b.

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Figure S4. 13C NMR / DEPT spectra (75.5 MHz, DMSO-d6) of compound 1b.
Figure S5. 1H NMR spectra (300 MHz, DMSO-d6) of compound 1c.

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Figure S6. 13C NMR / DEPT spectra (75.5 MHz, DMSO-d6) of compound 1c.
Figure S7. 1H NMR spectra (300 MHz, DMSO-d6) of compound 2a.

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Figure S8. 13C NMR / DEPT spectra (75.5 MHz, DMSO-d6) of compound 2a.
Figure S9. 1H NMR spectra (300 MHz, DMSO-d6) of compound 2b.

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Figure S10. 13C NMR / DEPT spectra (75.5 MHz, DMSO-d6) of compound 2b.
Figure S11. HMQC spectra of compound 2b.

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Figure S12. 1H NMR spectra (300 MHz, DMSO-d6) of compound 2c.
Figure S13. 13C NMR / DEPT spectra (75.5 MHz, DMSO-d6) of compound 2c.

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Figure S14. 1H NMR spectra (300 MHz, DMSO-d6) of compound 3a.
Figure S15. 13C NMR / DEPT spectra (75.5 MHz, DMSO-d6) of compound 3a.

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Figure S16. HMQC spectra of compound 3a.
Figure S17. 1H NMR spectra (300 MHz, DMSO-d6) of compound 3b.

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Figure S18. 13C NMR / DEPT spectra (75.5 MHz, DMSO-d6) of compound 3b.
Figure S19. HMQC spectra of compound 3b.

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Figure S20. 1H NMR spectra (300 MHz, DMSO-d6) of compound 3c.
Figure S21. 13C NMR / DEPT spectra (75.5 MHz, DMSO-d6) of compound 3c.

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Figure S22. HMQC spectra of compound 3c.
Figure S23. 1H NMR spectra (300 MHz, DMSO-d6) of compound 4a.

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Figure S24. 13C NMR / DEPT spectra (75.5 MHz, DMSO-d6) of compound 4a.
Figure S25. HMQC spectra of compound 4a.

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Figure S26. 1H NMR spectra (300 MHz, DMSO-d6) of compound 4b.
Figure S27. 13C NMR / DEPT spectra (75.5 MHz, DMSO-d6) of compound 4b.

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Figure S28. HMQC spectra of compound 4b.
Figure S29. 1H NMR spectra (300 MHz, DMSO-d6) of compound 4c.

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Figure S30. 13C NMR / DEPT spectra (75.5 MHz, DMSO-d6) of compound 4c.
Figure S31. HMQC spectra of compound 4c.

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Figure S32. 1H NMR spectra (300 MHz, DMSO-d6) of compound 5a.
Figure S33. 13C NMR / DEPT spectra (75.5 MHz, DMSO-d6) of compound 5a.

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Figure S34. HMQC spectra of compound 5a.
Figure S35. 1H NMR spectra (300 MHz, DMSO-d6) of compound 5b.

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Figure S36. 13C NMR / DEPT spectra (75.5 MHz, DMSO-d6) of compound 5b.
Figure S37. HMQC spectra of compound 5b.