Synthesis and biological evaluation of new [1,2,4]triazino[5,6-b]indol-3-ylthio-1,3,5-triazines and [1,2,4]triazino[5,6-b]indol-3-ylthio-pyrimidines against Leishmania donovani

Article abstract of DOI:10.1016/j.ejmech.2010.02.015

A series of [1,2,4]triazino[5,6-b]indol-3-ylthio-1,3,5-triazines and [1,2,4]triazino[5,6-b]indol-3-ylthio-pyrimidines were synthesized and screened for their in vitro antileishmanial activity against Leishmania donovani. Among all, 8 compounds have shown more than 90% inhibition against promastigotes and IC₅₀ in the range of 4.01-57.78 μM against amastigotes. Compound 5, a triazino[5,6-b]indol-3-ylthio-1,3,5-triazine derivative was found to be the most active and least toxic with 20- & 10-fold more selectivity (S.I. = 56.61) as compared to that of standard drugs pentamidine and sodium stibogluconate (SSG), respectively.

Full text of DOI:10.1016/j.ejmech.2010.02.015

European Journal of Medicinal Chemistry 45 (2010) 2359e2365
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Synthesis and biological evaluation of new [1,2,4]triazino[5,6-b]
indol-3-ylthio-1,3,5-triazines and [1,2,4]triazino[5,6-b]indol-3-ylthio-pyrimidines
against Leishmania donovani
a
a
b
b
b
c
Leena Gupta , Naresh Sunduru , Aditya Verma , Saumya Srivastava , Suman Gupta , Neena Goyal ,
a,
*
Prem M.S. Chauhan
Division of Medicinal and Process Chemistry, Central Drug Research Institute, MG Road, Lucknow 226001, U.P., India
Division of Parasitology, Central Drug Research Institute, Lucknow, U.P., India
a
b
c
Biochemistry Division, Central Drug Research Institute, Lucknow, U.P., India
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 20 August 2009
Received in revised form
A series of [1,2,4]triazino[5,6-b]indol-3-ylthio-1,3,5-triazines and [1,2,4]triazino[5,6-b]indol-3-ylthio-
pyrimidines were synthesized and screened for their in vitro antileishmanial activity against Leishmania
donovani. Among all, 8 compounds have shown more than 90% inhibition against promastigotes and IC50
29 January 2010
in the range of 4.01e57.78
triazine derivative was found to be the most active and least toxic with 20- & 10-fold more selectivity
S.I. ¼ 56.61) as compared to that of standard drugs pentamidine and sodium stibogluconate (SSG),
respectively.
mM against amastigotes. Compound 5, a triazino[5,6-b]indol-3-ylthio-1,3,5-
Accepted 4 February 2010
Available online 12 February 2010
(
Keywords:
Ó 2009 Published by Elsevier Masson SAS.
Leishmaniasis
Triazino[5,6-b]indole
Pyrimidine
1,3,5-Triazine
1
. Introduction
forms of the disease [5]. Thus, affordable alternative drugs against
leishmaniasis are desperately needed and the search for them is
still a challenging task.
Leishmaniasis is vector-borne disease caused by blood and
tissue dwelling protozoan parasite species belonging to the genus
Leishmania. It is the second-largest parasitic killer of humankind
with its three clinical forms; Cutaneous Leishmaniasis and Muco-
cutaneous Leishmaniasis, which are less severe form of the disease
with usually self-healing ulcers. While Visceral Leishmaniasis, the
most severe form of the disease, can result in 100% mortality of
infected patients if not treated. They affect 12 million people in 88
countries, with 1.5e2 million new cases and 70000 deaths each
year [1]. The chemotherapy against leishmaniasis is mainly based
on antimony agents like sodium stibogluconate and meglumine
antimoniate, amphotericin B, miltefosine and paromomycin, which
is disappointing due to their serious side effects of toxicity [2,3].
And the emerged resistance against to antimonials [4], AIDS and
other immunosuppressive conditions have also escalated the risk of
infection and contributed to the appearance of new severe clinical
Dihydrofolate reductase (DHFR) has successfully been used as
a drug target in the area of parasitic diseases. But most of the
clinically used DHFR inhibitors show less selectivity for leishmanial
enzymes [6]. This is due to the over expression of the gene pteridine
reductase (PTR1) in some leishmanial mutants. This PTR1 has ability
to provide reduced pterins and folates and has the potential to act
as a by-pass or modulator of DHFR inhibition. Thus to stop the
folate biosynthesis that is essential for the survival of infection,
both PTR1 and DHFR have to be inhibited [7]. Selective inhibitors of
PTR1 or a single inhibitor that acts on both enzymes would
constitute a rational approach for new antileishmanial agents.
Earlier, pyrimidines were synthesized and evaluated as inhibi-
tors of leishmanial and trypanosomal dihydrofolate reductase [8],
while triazine class of compounds being the inhibitors of DHFR
[9e11] have also been identified as potential antileishmanial agents
[12e14]. While on other side, triazino[5,6-b]indole derivatives have
aroused considerable interest as a result of their broad spectrum of
antibacterial, antifungal and antiparasitic activities [15e17]. Based
on these observations we have designed and synthesized the two
classes of hybrid molecules, one the hybrids of [1,2,4]triazino[5,6-b]
*
Corresponding author. Tel.: þ91 522 2262411X4470; fax: þ91 522 2623405.
E-mail addresses: prem_chauhan_2000@yahoo.com, premsc58@hotmail.com
(
P.M.S. Chauhan).
0223-5234/$ e see front matter Ó 2009 Published by Elsevier Masson SAS.
doi:10.1016/j.ejmech.2010.02.015

2360
L. Gupta et al. / European Journal of Medicinal Chemistry 45 (2010) 2359e2365
indole with 1,3,5-triazine and the other one is of [1,2,4]triazino[5,6-
b]indole with pyrimidine. These compounds were screened for
their antileishmanial profile and have shown encouraging results
against Leishmania donovani.
medium 199 (Sigma chemical Co., USA) supplemented with 10%
foetal calf serum (GIBCO) and 1% penicillin (50 U/mL), streptomycin
(50 mg/mL) solution (Sigma) under pressure of G418 (Sigma). The in
vitro effect of the compounds on the growth of promastigotes was
assessed by monitoring the luciferase activity of viable cells after
treatment. The transgenic promastigotes of late log phase were
2
. Chemistry
5
seeded at 5 ꢀ10 /100
mL medium 199 well in 96-well flat-
bottomed microtiter (MT) plates (CELLSTAR) and incubated for 72 h
in medium alone or in the presence of serial dilutions of drugs
Synthesis of [1,2,4]triazino[5,6-b]indole-triazine derivatives
(5e15) and [1,2,4]triazino[5,6-b]-pyrimidine derivatives (16e26)
(1e10
mg/mL) in DMSO [20]. Parallel dilutions of DMSO were used
has been synthesized as outlined in the Scheme 1. N-methylisatin 1
was achieved by protecting NH of isatin using dimethyl sulfate in
methanolic KOH [18], which was cyclised by thiosemicarbazide [17]
to give 5-methyl-5H-[1,2,4]triazino[5,6-b]indole-3-thiol (2) The
intermediates 3-(4,6-dichloro-1,3,5-triazin-2-ylthio)-5-methyl-5H-
as controls. After incubation, an aliquot (50
mg/mL) of promastigote
suspension was aspirated from each well of a 96-well plate and
Ò
mixed with an equal volume of steady Glo reagent (Promega) and
luminescence was measured by a luminometer. The values were
expressed as relative luminescence unit (RLU). The inhibition of
parasitic growth is determined by comparison of the luciferase
activity of drug-treated parasites with that of untreated controls by
the general formula:
[1,2,4]triazino[5,6-b]indole (3) and 3-(2-chloro-6-methylpyrimi-
din-4-ylthio)-5-methyl-5H-[1,2,4]triazino[5,6-b]indole (4) were
synthesized by reacting compound 2 with 2,4,6-trichloro-1,3,5-
triazine and 6-methyl-2,4-dichloropyrimidine, respectively. Inter-
mediate 3 was subjected to nucleophilic substitution with various
amines (Table 1) in THF to yield targeted compounds (5e15), while
intermediate 4 produced the final compounds (16e26) on nucleo-
philic substitution with various amines at second position of
N ꢁ n ꢀ 100
Percentage Inhibition ¼
N
where N is average relative luminescence unit (RLU) of control
wells, and n is average RLU of treated wells.
2 3
pyrimidine in the presence of K CO in DMF [19]. All the above
synthesized compounds were well characterized by spectroscopic
methods such as IR, mass, NMR and elemental analyses.
3.1.2. Antiamastigote activity
In vitro activity: for assessing the activity of compounds against
3
3
3
. Biological activities
the amastigote stage of the parasite, mouse macrophage cell line
J774A.1) infected with promastigotes expressing luciferase firefly
reporter gene was used. Cells were seeded in a 96-well plate
(
.1. Material and method
4
(1.5 ꢀ10 cell/100
m
L/well) in RPMI-1640 containing 10% foetal calf
ꢂ
.1.1. Antipromastigote activity
serum and the plates were incubated at 37 C in a CO
2
incubator.
The L. donovani promastigotes (MHOM/IN/Dd8; originally
obtained from Imperial college, London) were transfected with
firefly luciferase gene and the transfectants were maintained in
After 24 h, the medium was replaced with fresh medium containing
5
stationary-phase promastigotes (2.25 ꢀ10 /100
mL/well). Promas-
tigotes invades the macrophage and are transformed into
O
O
a
N
N
b
N
O
N
O
SH
H
N
2
N
isatin
1
c
d
Cl
Cl
N
N
N
N
N
N
N
N
N
N
S
N
Cl
N
N
4
S
3
f
e
R
R
N
N
N
N
N
N
N
N
N
N
S
N
R
N
N
S
5-15
16-26
Scheme 1. Reagents and conditions: (a) Dimethyl sulfate, MeOH, 10% methanolic KOH, rt.; (b) thiosemicarbazide, K
2
CO3, water, reflux; (c) 2,4,6-trichloro-1,3,5-triazine, THF, rt; (d)
CO3, DMF, reflux.
6
-methyl-2,4-dichloropyrimidine, DIPEA, DMF, reflux; (e) various amines, K CO , THF, reflux; (f) different amines, K
2
3
2

L. Gupta et al. / European Journal of Medicinal Chemistry 45 (2010) 2359e2365
2361
Table 1
Antileishmanial in vitro activity against luciferase-promastigote system.
3.1.4. Cytotoxicity assay
The cell viability was determined using the MTT assay as
described by Tempone et al., 2005 [22] using the J774A.1 cell line,
which was obtained from Tissue Culture Laboratory, Central Drug
Research Institute, India. J774A.1 cell line was maintained in RPMI
medium (Sigma), supplemented with 10% foetal calf serum and
R
Comp. Percent inhibition Comp. Percent inhibition
No.
(at 40
m
g/mL)
No.
(at 40 mg/mL)
promastigotes
promastigotes
N
N
4
5
75.56
16
99.31
40 mg/mL gentamycin. Exponentially growing cells (1 ꢀ10 cells/
100
mL/well) were incubated with different drug concentrations for
ꢂ
72 h and were incubated at 37 C in a humidified mixture of CO
2
O
and 95% air in an incubator. Stock solutions of compounds were
initially dissolved in DMSO and further diluted with fresh complete
medium. After incubation, 25 mL of MTT reagent (5 mg/mL) in PBS
6
7
43.13
NI
17
18
NI
N
N
CH
3
medium, followed by syringe filtration were added to each well and
99.90
ꢂ
incubated at 37 C for 2 h. At the end of the incubation period, the
supernatant were removed by tilting plate completely without
N
N
C
2
H
5
disturbing cell layer and 150 mL of pure DMSO are added to each
8
9
99.95
93.17
19
20
99.99
99.73
well. After 15 min of shaking the readings were recorded as
absorbance at 544 nm on a microplate reader. The cytotoxic effect
were expressed as 50% lethal dose, i.e., as the concentration of
a compound which provoked a 50% reduction in cell viability
compared to cell in culture medium alone. CC50 values were esti-
mated through the preformed template as described by Huber and
Koella (1993) [23].
HN
HN
1
0
97.41
99.27
21
22
66.72
99.25
4. Results and discussion
N
H
11
A series of 11 hybrids of 1,3,5-triazine (a DHFR inhibitor) and
same number of hybrids of pyrimidine (also a DHFR inhibitor) were
synthesized to compare the structure activity relationship by
incorporating both of them separately with [1,2,4]triazino[5,6-b]
indole moiety. The in vitro biological activity of [1,2,4]tri-
azinoindole-triazine and [1,2,4]triazinoindole-pyrimidine deriva-
tives has shown interesting results against L. donovani and clearly
suggests that the [1,2,4]triazinoindole-triazines are better inhibi-
tors in comparison to [1,2,4]triazinoindole-pyrimidines.
HN(H
2
C)
2
N
N
O
O
1
1
1
1
2
3
4
5
77.11
NI
23
24
25
26
51.11
95.10
100
HN(H C)
2
3
H
N
The percentage inhibition of these compounds against pro-
mastigotes has been shown in Table 1. Among all 11 hybrids of
N
68.53
49.33
[1,2,4]triazinoindole-triazines, four compounds 8, 9, 10 and 11 have
shown more than 90% inhibition against promastigotes, while eight
compounds 16, 18, 19, 20, 22, 24, 25 and 26 of [1,2,4]triazinoindole-
pyrimidine hybrids shown same percentage of inhibition against
promastigotes. Compounds which have shown more than 75% of
inhibition against promastigotes, were further screened against
amastigote model and their IC50, MIC, CC50 and selectivity index (SI)
were given in Table 2. Compound 5, a [1,2,4]triazinoindole-[1,3,5]
triazine derivative with R ¼ piperidine, found to be the most active
H
N
N
99.93
Òa
Pentamidine
SSG (Sodium stibogluconate)b
Ò
NI: no inhibition.
a
Pentamidine shows 85e90% inhibition against promastigotes at 0.5 mg/ml.
SSG shows 40e50% inhibition against promastigotes at 940 mg/ml.
b
among all the synthesized compounds with an IC50 of 4.01
a MIC of 20.54 M. It was also found to be the least toxic with a CC50
of 227.04 M and thus made it to 20- & 10-fold more selective than
mM and
amastigote. The test material in appropriate concentrations
0.25e10
the previous medium and the plates were incubated at 37 C in
m
(
m
g/mL) in complete medium was added after replacing
m
ꢂ
the standard drugs Pentamidine and Sodium stibogluconate (SSG),
respectively, with a SI of 56.57. On the other hand, compound 16
which is a [1,2,4]triazinoindole-pyrimidine derivative having same
2
a CO incubator for 72 h. After incubation, the drug containing
medium was decanted and 50
m
L PBS was added in each well and
Ò
mixed with an equal volume of steady Glo reagent. After gentle
shaking for 1e2 min, the reading was taken in a luminometer [20].
The inhibition of parasitic growth is determined by comparison of
the luciferase activity of drug-treated parasites with that of
untreated controls as described above.
R showed IC50 of 25.70
in selectivity in comparison to compound 5, but comparable to that
of standard drug SSG. Similarly, compound of [1,2,4]tri-
azinoindole-triazine hybrid with R ¼ N-ethylpiperazine showed
IC of 15.51 M, MIC of 26.55 M and CC of 93.17 M, with SI of
mM and CC50 of 173.29 mM, led to its drop off
8
5
0
m
m
50
m
value 6.74, which is comparable to that of standard drug SSG. While
3.1.3. Data analysis
compound 19 of [1,2,4]triazinoindole-pyrimidine hybrid having
IC50 and IC90 were calculated by Probit analysis [21]. Compounds
same R, exhibited decreased potency of IC50 26.31
selectivity. Compound 11, a [1,2,4]triazinoindole-triazine derivative
having isopropyl as R, also exhibited better IC50 of 17.38 M as
compared to its respective [1,2,4]triazinoindole-pyrimidine
analogue 22 (IC50 ¼ 29.64 M) with almost same selectivity. While
compound 20 showed good IC of 18.33 M among all pyrimidine
mM and poor
with more than 15
compounds with IC50 between 15 and 5
moderately active and less than
mg/mL IC50 were considered as inactive while
m
m
g/mL were considered as
g/mL as highly active
m
5
compounds. These values were expressed in micromolar (
concentrations using their respective molecular weights.
mM)
m
5
0
m

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L. Gupta et al. / European Journal of Medicinal Chemistry 45 (2010) 2359e2365
Table 2
In vitro activity against MQ-amastigotes and cytotoxicity.
Comp. No.
In vitro activity against amastigotes
Cytotoxicity against
J774A.1 cell lines
CC50 (mM)
SI (selectivity index)
CC50/IC50
IC50
(
mM)
MIC (m
M)a
5
8
9
4.01
15.51
NI
NI
17.38
NI
25.70
57.78
26.30
18.33
29.64
NI
20.54
26.55
ND
ND
90.53
ND
138.82
68.69
90.80
110.21
93.75
ND
227.04
93.17
17.07
ND
64.49
ND
173.29
29.21
28.14
88.39
108.71
ND
56.61
6.00
NA
NA
3.71
NA
6.74
0.50
1.06
4.82
3.66
NA
10
11
12
16
18
19
20
22
24
25
26
NI
NI
20.43
71.90
ND
ND
>168.71
163.89
ND
ND
52.82
398.26
NA
NA
2.58
5.53
Ò
Pentamidine
SSG
Ò
NI: no inhibition at 40 mg/mL; ND: not done; NA; not available.
a
MIC: minimum inhibitory concentration required for more than 90% inhibition.
derivatives, with improved selectivity on replacing R with n-
butylamine. On the basis of above discussion it is evident that
d
(ppm) 7.43e7.35(m, 2H), 7.07(m, 1H), 6.84(m, 1H), 3.21(s, 3H). 13
(CDCl , 50 MHz): 171.6, 152.7, 144.2, 131.2, 125.3, 124.6, 123.2, 108.9,
25.4. Anal. Calc. for C NO : C: 67.07, H: 4.38, N: 8.69. Found: C:
67.45, H: 4.66, N: 8.45.
C
3
[1,2,4]triazinoindole-[1,3,5]triazine hybrids are more potent anti-
H
9 7
2
leishmanial agents as compared to their, respective, [1,2,4]tri-
azinoindole-pyrimidine hybrids.
In conclusion, Leishmania is influencing the humankind with its
morbidity and mortality. The development of efficient chemo-
therapy is urgently required but still kept aside due to lack of
interest and financial support. As our research is oriented to the
development of novel heterocycles as anti-infectious agents, we
synthesized hybrids of 1,3,5-triazine and pyrimidine as anti-
leishmanial agents in the past and optimization of these hybrids is
still producing the promising results against leishmania. Therefore,
carry-over of research on these heterocycles is trustworthy for
generating efficient antileishmanials.
5.2. Synthesis of compound 2
A mixture of 1 (0.1 mol), thiosemicarbazide (0.1 mol) and K CO
(0.15 mol) in 500 mL of water was refluxed with stirring for 3 h. On
cooling the mixture was filtered and precipitated by acidification
with acetic acid. The solid was washed with water and dried to
obtain 2 as yellow solid.
2
3
5.2.1. 5-Methyl-5H-[1,2,4]triazino[5,6-b]indole-3-thiol (2)
ꢂ
Yield: 72%; mp > 250 C (Decompose); MS: 217 (M þ 1); IR
ꢁ1
1
(
KBr): 3108, 2935, 2856, 1565, 1441, 1076 cm
3
; H NMR (CDCl ,
5
. Experimental
200 MHz):
d
(ppm) 8.85(bs, 1H), 8.46(d, 1H, J ¼ 7.14 Hz), 7.68(m,
13
1H), 7.51e7.42(m, 2H), 3.91(s, 3H). C (CDCl
3
, 50 MHz): 141.6, 132.2,
S:
IR spectra were recorded on Beckman Aculab-10, PerkinElmer
81 and FTIR 8210 PC, Schimadzu spectrophotometers either on
131.4, 123.8, 122.7, 121.7, 117.5, 110.4, 27.7. Anal. Calc. for C10H N
C: 55.54, H: 3.73, N: 25.91. Found: C: 55.37, H: 3.88, N: 25.65.
8 4
8
KBr discs or in neat. Nuclear magnetic resonance (NMR) spectra
were recorded on either Bruker Avance DRX-300 MHz or Bruker
DPX 200 FT spectrometers using TMS as an internal reference. EI
mass spectra were recorded on JEOL JMS-D-300 spectrometer with
the ionization potential of 70 eV and ES mass spectra on Quantro-II,
micromass. Chemical analysis was carried out on Carlo-Erba-1108
instrument. The melting points were recorded on an electrically
heated melting point apparatus and are uncorrected.
5.3. Synthesis of compound 3
To a stirred solution of cyanuric chloride (1.2 equiv.) in dry THF,
compound 2 (1 equiv.) was added slowly and stirred for 3 h. at rt.
After the completion of reaction, the reaction mixture was evapo-
rated to dryness and the solid residue obtained was purified with
column chromatography using silica gel as an adsorbent to obtain
desired compound 3.
5.1. Synthesis of compound 1
5
.3.1. 3-(4,6-Dichloro-1,3,5-triazin-2-ylthio)-5-methyl-5H-[1,2,4]
triazino[5,6-b]indole (3)
Yield: 60%; mp: 152e155 C; MS: 363 (M þ 1); IR (KBr): 3116,
To a suspension of (0.1 mol) of isatin in 200 ml of anhydrous
ꢂ
methanol, 100 ml of 10% methanolic potassium hydroxide solution
was added in portions with stirring for 30 min. To this purple
mixture, 15 ml of dimethyl sulfate was added and after 1 h, the
solution was filtered to remove potassium methyl sulfate. After
removal of about 250 ml of solvent under reduced pressure, 40 ml
of warm water was added to the residue obtained. On cooling,
orange precipitate occurred which was filtered and dried to obtain
compound 1.
ꢁ
1 1
2931, 2851, 1583, 1540, 1435, 1298, 1182, 1064, 721 cm ; H NMR
(CDCl , 200 MHz):
(ppm) 8.40(d, 1H, J ¼ 7.24 Hz), 7.84(m, 1H), 7.56
(m, 2H), 3.85(s, 3H). C (CDCl
132.1, 123.4, 122.5, 117.5, 110.2, 27.7. Anal. Calc. for C13
3
d
13
3
, 50 MHz): 163.9, 147.8, 142.5, 141.8,
Cl S: C:
H
7
2 7
N
42.87, H: 1.94, N: 26.92. Found: C: 42.99, H: 1.85, N: 26.74.
5.4. Synthesis of compound 4
5
.1.1. 1-Methylindoline-2,3-dione (1)
To a solution of 2 (1 equiv.) in dry DMF, DIPEA (1.5 equiv.) was
added and stirred at rt. for 1 h. After that 6-methyl-2,4-dichlor-
opyrimidine (1.2 equiv.) was added and allowed to stir at rt. for 4 h.
ꢂ
Yield: 75%; mp: 80e82 C; MS: 162 (M þ 1); IR (KBr): 3029,
ꢁ1
1
1725, 1617, 1490, 1464, 752 cm
;
3
H NMR (CDCl , 200 MHz):

L. Gupta et al. / European Journal of Medicinal Chemistry 45 (2010) 2359e2365
2363
After the completion of reaction, the mixture was evaporated to
dryness and the solid obtained was dissolved in water and
extracted with DCM. The organic layer was washed with brine
solution (three times), with water (three times), and dried over
Calc. for C25
6.62, N: 29.16.
33
H N11S: C: 57.78, H: 6.40, N: 29.65. Found: C: 57.99, H:
2
4
5.5.5. N ,N -dibutyl-6-(5-methyl-5H-[1,2,4]triazino[5,6-b]indol-3-
anhydrous Na
2
SO
4
and concentrated to obtain the intermediate 4.
ylthio)-1,3,5-triazine-2,4-diamine (9)
ꢂ
Yield: 68%; mp: 138e140 C; MS: 438 (M þ 1); IR (KBr): 3348,
ꢁ
1 1
5.4.1. 3-(2-Chloro-6-methylpyrimidin-4-ylthio)-5-methyl-5H-
3112, 2928, 2875, 1542, 1490, 1452, 1287, 1232, 1174, 1068 cm ; H
[
1,2,4]triazino[5,6-b]indole (4)
Yield: 62%; mp: 144e146 C; MS: 343 (M þ 1); IR (KBr): 3116,
NMR (CDCl
3
, 200 MHz):
d
(ppm) 8.52(d, 1H, J ¼ 7.54 Hz), 7.77(m,
ꢂ
1H), 7.55e7.50(m, 2H), 3.94(s, 3H), 3.28e3.06(m, 4H), 1.49e1.29(m,
ꢁ
1
1
13
2
(
931, 2851, 1583, 1540, 1435, 1298, 1182, 1064, 721 cm ; H NMR
, 200 MHz):
(ppm) 8.46(d, 1H, J ¼ 8.10 Hz), 7.74(t, 1H,
J ¼ 7.48 Hz), 7.55e7.49(m, 2H), 6.98(s, 1H), 3.84(s, 3H), 2.32(s, 3H).
8H), 0.93(t, 3H, J ¼ 5.53 Hz). C (CDCl
142.3, 141.9,132.6, 123.1,122.5, 117.6, 110.1, 40.3, 31.4, 27.8, 19.9,13.4.
Anal. Calc. for C21 S: C: 57.64, H: 6.22, N: 28.81. Found: C:
57.34, H: 6.12, N: 28.98.
3
, 50 MHz): 164.3, 146.8,
CDCl
3
d
27 9
H N
1
3
C (CDCl
23.8,123.4,119.7,118.5,110.2, 27.7, 24.4. Anal. Calc. for C15
C: 52.55, H: 3.23, N: 24.52. Found: C: 52.76, H: 3.14, N: 24.61.
3
, 50 MHz): 171.4, 169.6, 163.2, 160.7, 146.3, 142.5, 132.1,
1
H11ClN S:
6
2
4
5.5.6. N ,N -di-tert-butyl-6-(5-methyl-5H-[1,2,4]triazino[5,6-b]
indol-3-ylthio)-1,3,5-triazine-2,4-diamine (10)
ꢂ
Yield: 55%; mp: 176e178 C; MS: 438 (M þ 1); IR (KBr): 3342,
ꢁ
1 1
5.5. General procedure for the synthesis of compounds 5e15
3079, 2931, 2852, 1546, 1489, 1445, 1290, 1219, 1183, 1075 cm ; H
NMR (CDCl
1H), 7.69e7.66(m, 2H), 3.03(s, 3H), 1.14(s, 18H). C (CDCl
164.5, 146.8, 142.4, 141.8, 131.6, 123.1, 122.7, 117.6, 110.1, 51.9, 29.7,
27.5. Anal. Calc. for C21 S: C: 57.64, H: 6.22, N: 28.81. Found: C:
57.66, H: 6.25, N: 28.79.
3
, 200 MHz):
d
(ppm) 8.67(d, 1H, J ¼ 7.21 Hz), 7.92(m,
13
A mixture of 3 (1 equiv.) and respective amine (2 equiv.) as
described in Table 1 and K CO (1.2 equiv.) in dry THF was refluxed
with stirring for 7 h. After the completion of reaction, mixture was
evaporated to dryness and the solid residue was purified with
column chromatography using silica gel as an adsorbent to obtain
final targeted compounds 5e15.
3
, 50 MHz):
2
3
27 9
H N
2
4
5.5.7. N ,N -diisopropyl-6-(5-methyl-5H-[1,2,4]triazino[5,6-b]
indol-3-ylthio)-1,3,5-triazine-2,4-diamine (11)
ꢂ
5
5
.5.1. 3-(4,6-Di(piperidin-1-yl)-1,3,5-triazin-2-ylthio)-5-methyl-
Yield: 59%; mp: 148e150 C; MS: 410 (M þ 1); IR (KBr): 3385,
ꢁ
1 1
H-[1,2,4]triazino[5,6-b]indole (5)
3056, 2934, 2852, 1543, 1490, 1434, 1285, 1230, 1178, 1076 cm ; H
ꢂ
Yield: 55%; mp: 178e180 C; MS: 462 (M þ 1); IR (KBr): 3054,
NMR (CDCl
3
, 200 MHz):
d
(ppm) 8.45(d, 1H, J ¼ 6.96 Hz), 7.87(m,
ꢁ1 1
2
933, 2850, 1544, 1491, 1444, 1295, 1229, 1175, 1066 cm ; H NMR
2H), 7.55(m, 1H), 4.02(bs, 2H), 3.99e3.95(m, 2H), 3.85(s, 3H), 1.06(d,
13
(
CDCl
J ¼ 7.42 Hz), 7.58e7.55(m, 2H), 3.91(s, 3H), 3.71(m, 8H), 1.55e1.47
m, 12H). 13C (CDCl
, 50 MHz): 164.7, 146.8, 142.6, 141.3, 132.4, 123.8,
22.1, 117.5, 110.4, 50.9, 27.3, 26.2, 25.5. Anal. Calc. for C23 S: C:
3
, 200 MHz):
d
(ppm) 8.46(d, 1H, J ¼ 7.68 Hz), 7.85(t, 1H,
12H, J ¼ 3.96 Hz). C (CDCl , 50 MHz): 163.9, 146.8, 142.3, 141.8,
3
132.2, 123.1, 122.7, 117.5, 110.2, 47.2, 27.7, 24.3. Anal. Calc. for
19 23 9
C H N S: C: 55.73, H: 5.66, N: 30.78. Found: C: 55.66, H: 5.74, N:
(
1
5
3
H N
27 9
30.95.
9.85, H: 5.90, N: 27.31. Found: C: 59.76, H: 5.88, N: 27.40.
2
4
5
.5.8. 6-(5-Methyl-5H-[1,2,4]triazino[5,6-b]indol-3-ylthio)-N ,N -
5
.5.2. 4,4'-(6-(5-Methyl-5H-[1,2,4]triazino[5,6-b]indol-3-ylthio)-
bis(2-morpholinoethyl)-1,3,5-triazine-2,4-diamine (12)
ꢂ
1,3,5-triazine-2,4-diyl)dimorpholine (6)
Yiled: 67%; 210e212 C; MS: 552 (M þ 1); IR (KBr): 3442, 3064,
ꢂ
ꢁ1 1
Yield: 58%; mp: 218e220 C; MS: 466 (M þ 1); IR (KBr): 3061,
2930, 2856, 1541, 1490, 1444, 1293, 1231, 1174, 1082 cm ; H NMR
ꢁ1 1
2
934, 2856, 1540, 1493, 1445, 1297, 1230, 1166, 1072 cm ; H NMR
(CDCl
3
, 200 MHz):
d
(ppm) 8.47(d, 1H, J ¼ 7.12 Hz), 7.76(m, 1H), 7.56
(
CDCl
J ¼ 7.58 Hz), 7.59e7.51(m, 2H), 3.93(s, 3H), 3.83e3.66(m, 16H).
CDCl , 50 MHz): 164.3, 145.9, 142.6, 141.5, 132.4, 123.5, 122.6, 117.8,
10.3, 67.5, 50.2, 27.2. Anal. Calc. for C21 S: C: 54.18, H: 4.98,
N: 27.08. Found: C: 54.20, H: 4.99, N: 27.06.
3
, 200 MHz):
d
(ppm) 8.54(d, 1H, J ¼ 7.24 Hz), 7.82(t, 1H,
(m, 2H), 3.88(s, 3H), 3.51e3.35(m, 12H), 2.69(m, 8H), 2.13e2.09(m,
13
13
C
3
4H). C (CDCl , 50 MHz): 164.3, 146.8, 142.3, 141.9, 132.5, 123.6,
(
1
3
122.7, 117.5, 110.2, 67.3, 57.4, 53.1, 42.6, 27.7. Anal. Calc. for
25 33 11 2
C H N O S: C: 54.43, H: 6.03, N: 27.93. Found: C: 54.75, H: 6.24,
N: 27.70.
H
23
N
9
O
2
2
4
5.5.3. 3-(4,6-Bis(4-methylpiperazin-1-yl)-1,3,5-triazin-2-ylthio)-5-
5.5.9. 6-(5-Methyl-5H-[1,2,4]triazino[5,6-b]indol-3-ylthio)-N ,N -
methyl-5H-[1,2,4]triazino[5,6-b]indole (7)
bis(3-morpholinopropyl)-1,3,5-triazine-2,4-diamine (13)
ꢂ
ꢂ
Yield: 64%; mp: 198e200 C; MS: 492 (M þ 1); IR (KBr): 3108,
Yield: 64%; mp: 232e234 C; MS: 580 (M þ 1); IR (KBr): 3436,
ꢁ1
1
ꢁ1 1
2
928, 2845, 1537, 1484, 1440, 1293, 1235, 1162, 1082 cm ; H NMR
3045, 2935, 2860, 1550, 1492, 1443, 1280, 1231, 1185, 1067 cm ; H
(
CDCl
J ¼ 5.37 Hz), 7.43e7.33(m, 2H), 3.97(s, 3H), 3.58(m, 8H), 2.77(m, 8H),
.45(s, 6H). 13C (CDCl
, 50 MHz): 163.2, 146.8, 142.7, 141.5, 132.1,
23.9, 122.7, 117.6, 110.4, 53.2, 49.2, 43.6, 27.7. Anal. Calc. for
11S: C: 56.19, H: 5.95, N: 31.34. Found: C: 56.34, H: 5.77, N:
3
, 200 MHz):
d
(ppm) 8.31(d, 1H, J ¼ 5.20 Hz), 7.64(t, 1H,
NMR (CDCl
3
, 200 MHz):
d
(ppm) 8.43(d, 1H, J ¼ 6.98 Hz), 7.72(m,
1H), 7.49(m, 2H), 6.82(bs, 2H), 3.86(s, 3H), 3.59e3.40(m, 12H), 2.36
13
2
1
C
3
3
(m, 12H), 1.72e1.69(m, 4H). C (CDCl
141.8, 132.6, 123.2, 122.7, 117.5, 110.1, 66.4, 61.3, 54.1, 30.2, 27.6, 24.6.
Anal. Calc. for C27 S: C: 55.94, H: 6.43, N: 26.58. Found: C:
55.66, H: 6.24, N: 26.69.
3
, 50 MHz): 164.5, 146.8, 142.2,
23
H
29
N
37 11 2
H N O
1.42.
1
1'
5
.5.4. 3-(4,6-Bis(4-ethylpiperazin-1-yl)-1,3,5-triazin-2-ylthio)-5-
5.5.10. N ,N -(6-(5-methyl-5H-[1,2,4]triazino[5,6-b]indol-3-
2
2
methyl-5H-[1,2,4]triazino[5,6-b]indole (8)
ylthio)-1,3,5-triazine-2,4-diyl)bis(N ,N -dimethylethane-1,2-
diamine) (14)
ꢂ
Yield: 61%; mp: 230e232 C; MS: 520 (M þ 1); IR (KBr): 3072,
ꢁ
1
1
ꢂ
2
926, 2861, 1547, 1485, 1443, 1295, 1228, 1177, 1074 cm ; H NMR
Yield: 59%; mp: 189e191 C; MS: 468 (M þ 1); IR (KBr): 3435,
ꢁ1 1
(
CDCl
3
, 200 MHz):
d
(ppm) 8.46(d, 1H, J ¼ 7.04 Hz), 7.78e7.75(m,
3061, 2932, 2854, 1547, 1482, 1295, 1228, 1174, 1056 cm ; H NMR
1
H), 7.57e7.48(m, 2H), 3.89(s, 3H), 3.45e3.24(m, 16H), 2.75(m, 4H),
(CDCl
(m, 2H), 3.91(s, 3H), 3.49(m, 4H), 2.58(m, 4H), 2.32(s, 12H).
(CDCl , 50 MHz): 163.9, 145.6, 142.4, 141.7, 132.2, 131.4, 123.9, 122.7,
3
, 200 MHz):
d
(ppm) 8.41(d, 1H, J ¼ 7.26 Hz), 7.82(m, 1H), 7.55
1
3
13
1
.37(t, 6H, J ¼ 6.65 Hz). C (CDCl
3
, 50 MHz): 164.3, 146.8, 142.5,
C
141.8, 131.7, 123.1, 122.7, 117.5, 110.2, 53.4, 52.8, 50.7, 27.7, 12.5. Anal.
3

2364
L. Gupta et al. / European Journal of Medicinal Chemistry 45 (2010) 2359e2365
1
17.5,110.3, 58.7, 45.1, 42.2, 27.8. Anal. Calc. for C21
H
29
N11S: C: 53.94,
5.6.5. N-butyl-4-methyl-6-(5-methyl-5H-[1,2,4]triazino[5,6-b]
H: 6.25, N: 32.95. Found: C: 53.83, H: 6.47, N: 32.82.
indol-3-ylthio)pyrimidin-2-amine (20)
ꢂ
Yield: 56%; mp: 153e155 C; MS: 380 (M þ 1); IR (KBr): 3453,
1
1'
ꢁ1 1
5
.5.11. N ,N -(6-(5-methyl-5H-[1,2,4]triazino[5,6-b]indol-3-
3115, 2927, 2856, 1580, 1546, 1434, 1288, 1187, 1067 cm ; H NMR
2
2
ylthio)-1,3,5-triazine-2,4-diyl)bis(N ,N -diethylethane-1,2-diamine)
(CDCl
3
, 200 MHz):
d
(ppm) 8.48(d, 1H, J ¼ 8.12 Hz), 7.76 (t, 1H,
(
15)
J ¼ 7.72 Hz), 7.54e7.47(m, 2H), 6.93(s, 1H), 5.45(bs, 1H), 3.87(s, 3H),
ꢂ
Yield: 56%; mp: 201e203 C; MS: 524 (M þ 1); IR (KBr): 3447,
3.31(m, 2H), 2.33(s, 3H), 1.47(m, 2H), 1.25(m, 2H), 0.85(t, 3H,
ꢁ
1
1
13
3
052, 2934, 2855, 1546, 1479, 1289, 1238, 1175, 1066 cm ; H NMR
200 MHz):
(ppm) 8.47(d, 1H, J ¼ 6.80 Hz), 7.89(m, 1H), 7.57
m, 2H), 3.88(s, 3H), 3.54(m, 4H), 3.13(m,12H),1.4(t,12H, J ¼ 6.75 Hz).
J ¼ 6.88 Hz). C (CDCl
3
, 50 MHz): 170.4, 169.6, 163.5, 160.2, 146.8,
(
CDCl
3
d
142.9, 132.6, 123.7, 123.4, 119.6, 118.1, 110.6, 45.8, 33.2, 27.7, 24.5,
20.6, 14.24. Anal. Calc. for C19 S: C: 60.14, H: 5.58, N: 25.84.
Found: C: 60.54, H: 5.67, N: 25.91.
(
21 7
H N
1
3
C(CDCl
3
, 50 MHz): 164.1,145.5,142.3,141.4,132.2,131.3,123.6,122.7,
11S: C:
1
17.1, 110.2, 52.2, 47.2, 46.8, 27.7, 12.2. Anal. Calc. for C25H N
37
57.34, H: 7.12, N: 29.42. Found: C: 57.53, H: 7.02, N: 29.54.
5.6.6. N-tert-butyl-4-methyl-6-(5-methyl-5H-[1,2,4]triazino[5,6-b]
indol-3-ylthio)pyrimidin-2-amine (21)
ꢂ
5.6. General procedure for the synthesis of compounds 16e26
Yield: 52%; mp: 207e209 C; MS: 380 (M þ 1); IR (KBr): 3448,
ꢁ1 1
3
120, 2935, 2844, 1579, 1542, 1435, 1287, 1182, 1072 cm ; H NMR
To a mixture of 4 (1 equiv.) and K CO (1.5 equiv.) in dry DMF,
2
3
(CDCl
3
200 MHz):
d
(ppm) 8.48(d, 1H, J ¼ 7.44 Hz), 7.78 (t, 1H,
respective amine (1.2 equiv.) as described in Table 1, was added and
this reaction mixture was refluxed for 8 h. After the completion of
reaction, mixture was evaporated to dryness and the solid residue
was purified with column chromatography using silica gel as an
adsorbent to obtain final targeted compounds 16e26.
J ¼ 7.41 Hz), 7.55e7.52(m, 2H), 6.98(s, 1H), 3.88(s, 3H), 2.53(s, 3H),
13
3
1.25(s, 9H). C (CDCl , 50 MHz): 170.4, 169.7, 163.5, 160.4, 146.8,
142.9, 132.3, 123.9, 123.3, 119.6, 118.1, 110.6, 51.3, 30.1, 28.2, 24.6.
Anal. Calc. for C19 S: C: 60.14, H: 5.58, N: 25.84. Found: C:
60.22, H: 5.69, N: 25.57.
21 7
H N
5
5
.6.1. 5-Methyl-3-(6-methyl-2-(piperidin-1-yl)pyrimidin-4-ylthio)-
5.6.7. N-isopropyl-4-methyl-6-(5-methyl-5H-[1,2,4]triazino[5,6-b]
H-[1,2,4]triazino[5,6-b]indole (16)
indol-3-ylthio)pyrimidin-2-amine (22)
ꢂ
ꢂ
Yield: 61%; mp: 169e171 C; MS: 392 (M þ 1); IR (KBr): 3111,
Yield: 67%; mp: 97e99 C; MS: 366 (M þ 1); IR (KBr): 3452,
ꢁ1
1
ꢁ1 1
2
930, 2852, 1583, 1536, 1438, 1289, 1188, 1071 cm
;
H NMR
3123, 2930, 2854, 1587, 1555, 1436, 1281, 1185, 1062 cm ; H NMR
(
CDCl
3
, 200 MHz):
d
(ppm) 8.48(d, 1H, J ¼ 7.98 Hz), 7.75(t, 1H,
(CDCl
3
200 MHz):
d
(ppm) 8.41(d, 1H, J ¼ 5.20 Hz), 7.71(t, 1H,
J ¼ 7.24 Hz), 7.54e7.47(m, 2H), 6.85(s, 1H), 3.86(s, 3H), 3.74(m, 4H),
J ¼ 4.86 Hz), 7.49e7.42(m, 2H), 6.68(s, 1H), 3.85(s, 3H), 3.64e3.60
13
13
2
.35(s, 3H), 1.59(m, 6H). C (CDCl
61.2, 146.9, 142.4, 131.8, 123.6, 123.2, 118.2, 110.5, 109.1, 45.2, 27.8,
6.2, 25.3, 24.7. Anal. Calc. for C20 S: C: 61.36, H: 5.41, N: 25.04.
Found: C: 61.43, H: 5.52, N: 25.14.
3
, 50 MHz): 170.5, 167.5, 165.1,
(m, 1H), 2.28(s, 3H), 1.55(d, 6H, J ¼ 3.83 Hz). C (CDCl
170.5, 169.6, 163.8, 160.4, 146.8, 142.9, 132.3, 123.9, 123.4, 119.5,
118.1, 110.7, 47.3, 27.8, 24.4, 24.3. Anal. Calc. for C18 S: C: 59.16,
H: 5.24, N: 26.83. Found: C: 59.23, H: 5.34, N: 26.52.
3
, 50 MHz):
1
2
H
21
N
7
19 7
H N
5.6.2. 4-(4-Methyl-6-(5-methyl-5H-[1,2,4]triazino[5,6-b]indol-3-
5.6.8. 4-Methyl-6-(5-methyl-5H-[1,2,4]triazino[5,6-b]indol-3-
ylthio)pyrimidin-2-yl)morpholine (17)
ylthio)-N-(2-morpholinoethyl)pyrimidin-2-amine (23)
ꢂ
ꢂ
Yield: 70%; mp: 203e205 C; MS: 394(M þ 1); IR (KBr): 3115, 2928,
Yield: 62%; mp: 216e218 C; MS: 437 (M þ 1); IR (KBr): 3448,
ꢁ
1
1
ꢁ1 1
2
864, 1580, 1543, 1436, 1288, 1178, 1072 cm
;
H NMR (CDCl
3
,
3122, 2927, 2848, 1580, 1565, 1434, 1283, 1187, 1065 cm ; H NMR
2
00 MHz):
d
(ppm) 8.41(d, 1H, J ¼ 5.62 Hz), 7.71e7.65(m, 1H),
(CDCl
3
, 200 MHz):
d
(ppm) 8.47(d, 1H, J ¼ 7.30 Hz), 7.76(t, 1H,
7.45e7.40(m, 2H), 6.88(s, 1H), 3.79(s, 3H), 3.68e3.62(m, 8H), 2.26(s,
J ¼ 7.44 Hz), 7.53e7.51(m, 2H), 6.96(s, 1H), 5.79(bs, 1H), 3.87(s, 3H),
13
13
3
1
H). C (CDCl
23.3,118.3,110.6,109.1, 67.6, 51.5, 27.7, 24.6. Anal. Calc. for C19
C: 58.00, H: 4.87, N: 24.92. Found: C: 58.22, H: 4.52, N: 24.85.
3
, 50 MHz): 171.5, 167.4, 165.1, 146.8, 142.4, 131.8, 123.6,
3
3.53(m, 4H), 3.25(m, 2H), 2.61(m, 6H), 2.32(s, 3H). C (CDCl ,
19 7
H N OS:
50 MHz): 171.2, 169.5, 163.5, 160.4, 146.6, 142.8, 132.1, 123.9, 123.8,
119.5, 118.1, 110.6, 67.2, 57.4, 53.5, 41.3, 27.8, 24.4. Anal. Calc. for
21 24 8
C H N OS: C: 57.78, H: 5.54, N: 25.67. Found: C: 57.70, H: 5.46, N:
5
4
.6.3. 5-Methyl-3-(6-methyl-2-(4-methylpiperazin-1-yl)pyrimidin-
25.74.
-ylthio)-5H-[1,2,4]triazino[5,6-b]indole (18)
ꢂ
Yield: 63%; mp: 238e240 C; MS: 407 (M þ 1); IR (KBr): 3124,
5.6.9. 4-Methyl-6-(5-methyl-5H-[1,2,4]triazino[5,6-b]indol-3-
ylthio)-N-(3-morpholinopropyl)pyrimidin-2-amine (24)
ꢁ1
1
2
929, 2854, 1585, 1540, 1438, 1291, 1183, 1075 cm
;
H NMR
ꢂ
(
CDCl
3
, 200 MHz):
d
(ppm) 8.43(d, 1H, J ¼ 6.98 Hz), 7.74 (t, 1H,
Yield: 61%; mp: 235e237 C; MS: 451 (M þ 1); IR (KBr): 3456,
ꢁ
1 1
J ¼ 7.42 Hz), 7.52e7.44(m, 2H), 6.87(s,1H), 3.83(s, 3H), 3.01e2.89(m,
3112, 2935, 2854, 1580, 1537, 1436, 1290, 1198, 1072 cm ; H NMR
13
7
1
5
H), 2.61(m, 4H), 2.28(s, 3H). C (CDCl
63.5, 1602, 146.7, 142.8, 132.3, 123.9, 123.3, 119.6, 118.1, 110.6, 55.8,
1.2, 46.6, 27.8, 24.4. Anal. Calc. for C20 S: C: 59.09, H: 5.45, N:
3
, 50 MHz): 171.5, 169.4,
(CDCl
3
, 200 MHz):
d
(ppm) 8.41(d, 1H, J ¼ 7.78 Hz), 7.84(m, 2H), 7.54
(d, 1H, J ¼ 4.08 Hz), 7.25(bs, 1H), 6.82(s, 1H), 3.82(s, 3H), 3.66e3.52
13
H
22
N
8
(m, 6H), 2.37e2.19(m, 9H), 1.62e1.52(m, 2H). C (CDCl
171.2, 169.4, 163.4, 160.4, 146.8, 142.9, 132.3, 123.8, 123.3, 119.4,
18.2, 110.6, 65.9, 61.2, 54.1, 30.2, 27.7, 24.6, 24.5. Anal. Calc. for
22 26 8
C H N OS: C: 58.65, H: 5.82, N: 24.87. Found: C: 56.86, H: 5.74, N:
3
, 50 MHz):
27.56. Found: C: 59.12, H: 5.40, N: 27.45.
1
5
.6.4. 3-(2-(4-Ethylpiperazin-1-yl)-6-methylpyrimidin-4-ylthio)-5-
methyl-5H-[1,2,4]triazino[5,6-b]indole (19)
24.89.
ꢂ
Yield: 60%; mp: 220e222 C; MS: 421 (M þ 1); IR (KBr): 3117,
ꢁ1
1
1
1
2
2
930, 2862,1584,1537,1444,1288,1185,1069 cm ; H NMR (CDCl
3
,
5.6.10. N ,N -dimethyl-N -(4-methyl-6-(5-methyl-5H-[1,2,4]
triazino[5,6-b]indol-3-ylthio)pyrimidin-2-yl)ethane-1,2-diamine
(25)
2
00 MHz):
d
(ppm) 8.40(d, 1H, J ¼ 4.81 Hz), 7.71 (t, 1H, J ¼ 5.06 Hz),
7.49e7.42(m, 2H), 6.79(s,1H), 3.81(s, 3H), 3.57e3.28(m, 8H), 2.41(m,
1
3
ꢂ
2
H), 2.24(s, 3H), 1.04(t, 3H, J ¼ 6.54 Hz). C (CDCl
3
, 50 MHz): 170.6,
Yield: 54%; mp: 197e199 C; MS: 395 (M þ 1); IR (KBr): 3436,
ꢁ
1 1
169.2,163.6,160.2,146.8,142.9,132.1,123.8,123.4,119.5,118.1,109.9,
3106, 2940, 2848, 1582, 1547, 1435, 1285, 1190, 1067 cm ; H NMR
5
5
3.4, 52.8, 50.8, 27.7, 24.6,12.3. Anal. Calc. for C21
.75, N: 26.65. Found: C: 59.92, H: 5.70, N: 26.45.
H
N
24 8
S: C: 59.98, H:
(CDCl
3
, 200 MHz):
d
(ppm) 8.41(d, 1H, J ¼ 7.64 Hz), 7.86(m, 2H),
7.54e7.53(m, 1H), 7.23(bs, 1H), 6.89(s, 1H), 3.82(s, 3H), 3.35(m, 2H),

L. Gupta et al. / European Journal of Medicinal Chemistry 45 (2010) 2359e2365
2365
2
1
5
5
.82(m, 2H), 2.39(s, 3H), 2.22(s, 6H); 13C (CDCl
69.6, 164.5, 161.1, 147.5, 142.9, 132.4, 123.7, 123.6, 119.5, 118.6, 110.9,
8.7, 45.2, 42.3, 27.7, 24.5. Anal. Calc. for C19 S: C: 57.85, H:
.62, N: 28.40. Found: C: 57.65, H: 5.43, N: 28.49.
3
, 50 MHz): 172.1,
[2] S.L. Croft, G.H. Coombs, Trends. Parasitol. 19 (2003) 502e508.
[
3] M. Ouellette, J. Drummelsmith, B. Papadopoulou, Drug. Resist. Updat. 7 (2004)
57e266.
4] S.L. Croft, S. Sundar, A.H. Fairlamb, Clin. Microbiol. Rev. 19 (2006) 111e126.
2
22 8
H N
[
[5] G. Harms, H. Feldmeier, Trop. Med. Int. Health. 7 (2002) 479e488.
[6] R.A. Neal, S.L. Croft, J. Antimicrob. Chemother. 14 (1984) 463e475.
[7] B. Nare, J. Luba, L.W. Hardy, S. Beverly, Parasitology 114 (1997) S101eS110.
[8] S.F. Chowdhury, V.B. Villamor, R.H. Guerrero, I. Leal, R. Brun, S.L. Croft, J.
M. Goodman, L. Maes, L.M. Ruiz-Perez, D.G. Pacanowska, I.H. Gilbert, J. Med.
Chem. 42 (1999) 4300e4312.
1
1
2
5.6.11. N ,N -diethyl-N -(4-methyl-6-(5-methyl-5H-[1,2,4]triazino
[5,6-b]indol-3-ylthio)pyrimidin-2-yl)ethane-1,2-diamine (26)
ꢂ
Yield: 55%; mp: 217e219 C; MS: 423 (M þ 1); IR (KBr): 3442,
[9] H. Lee, W. Chui, Bioorg. Med. Chem. 7 (1999) 1255e1262.
ꢁ
1 1
3109, 2925, 2862, 1585, 1537, 1435, 1290, 1186, 1072 cm ; H NMR
[
10] Y. Yuthavong, T. Vilaivan, N. Chareonsethakul, S. Kamchonwongpaisan,
W. Sirawaraporn, R. Quarrell, G. Lowe, J. Med. Chem. 43 (2000) 2738e2744.
11] S. Kamchonwongpaisan, R. Quarrell, N. Charoensetakul, R. Ponsinet,
T. Vilaivan, J. Vanichtanankul, B. Tarnchompoo, W. Sirawaraporn, G. Lowe,
Y. Yuthavong, J. Med. Chem. 47 (2004) 673e680.
(
CDCl
3
, 200 MHz):
d
(ppm) 8.43(d, 1H, J ¼ 7.64 Hz), 7.88(m, 1H),
[
7.52e7.46(m, 2H), 6.85(s, 1H), 3.86(s, 3H), 3.36(m, 2H), 3.12(m, 6H),
13
2
1
5
.34(s, 3H), 1.05(t, 6H, J ¼ 6.78 Hz). C (CDCl
69.6,163.2, 160.7,146.8, 142.7, 132.4, 123.9, 123.4, 119.8,118.5,110.1,
2.2, 47.3, 46.9, 27.7, 24.3, 12.2. Anal. Calc. for C21 S: C: 56.69,
3
, 50 MHz): 171.3,
[12] A. Kumar, S.B. Katiyar, S. Gupta, P.M.S. Chauhan, Eur. J. Med. Chem. 41 (2006)
06e113.
1
26 8
H N
[
13] N. Sunduru, A. Agarwal, S.B. Katiyar, N.N. Goyal, S. Gupta, P.M.S. Chauhan,
Bioorg. Med. Chem. 14 (2006) 7706e7715.
H: 6.20, N: 26.52. Found: C: 59.75, H: 6.03, N: 26.66.
[14] N.N. Sunduru, S. Palne, P.M.S. Chauhan, S. Gupta, Eur. J. Med. Chem. 44 (2009)
2473e2481.
Acknowledgement
[
[
15] V.J. Ram, Arch. Pharm. 313 (1980) 108e113.
16] J.M.Z. Gladych, R. Hornby, J.H. Hunt, D. Jack, J.J. Boyle, R.J. Ferlauto, R.F. Haff, C.
G. Kormendy, F.J. Stanfield, R.C. Stewart, J. Med. Chem. 15 (1972) 277e281.
L.G. thanks the University Grant Commission, New Delhi and N.
S. thanks the Council of Scientific and Industrial Research (India) for
the award of Senior Research Fellowship. We are also thankful to S.
A.I.F. Division, CDRI, Lucknow for providing spectroscopic data.
Thanks are also due to Mr. M. P. S. Negi, Division of Biometry &
Statistics, CDRI for data analysis. CDRI communication No: 7823.
[17] J.L. Kgokong, P.P. Smith, G.M. Matsabisa, Bioorg. Med. Chem. 13 (2005)
935e2942.
2
[
[
18] R.C. Elederfield, H.H. Rembges, J. Org. Chem. 32 (1967) 3809e3814.
19] W. Zhang, Org. Lett. 5 (2003) 1011e1013.
[20] A.S. Gupta, R.S. Sundar, N. Goyal, Antimicrobial. Agents. Chemother. 49 (2005)
776e3783.
3
[
[
21] D.J. Finney, Probit Analysis, third ed. Cambridge University Press, 1971.
22] A.G. Tempone, A.C.M.P. da Silva, C.A. Brandt, F.S. Martinez, S.E.T. Borborema, M.
A.B. da Silveira, H.F. de Andrade Jr., Antimicrobial. Agents. Chemother. 49
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