Discovery of new 1,3,5-triazine scaffolds with potent activityagainst Mycobacterium tuberculosis H37Rv

Article abstract of DOI:10.1016/j.ejmech.2010.04.017

A series of eighty one 2,4,6-trisubstituted-1,3,5-triazines were synthesized and evaluated in vitro for the growth inhibition of Mycobacterium tuberculosis H37Rv. Fifteen compounds from this series exhibited good to moderate activity with an MIC in the ra

Full text of DOI:10.1016/j.ejmech.2010.04.017

European Journal of Medicinal Chemistry 45 (2010) 3335e3345
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Discovery of new 1,3,5-triazine scaffolds with potent activity against
Mycobacterium tuberculosis H37Rv
Naresh Sunduru a, Leena Gupta a, Vinita Chaturvedi b, Richa Dwivedi b, Sudhir Sinha b,
,
Prem M.S. Chauhan a
*
a Medicinal and Process Chemistry Division, Central Drug Research Institute, CSIR, Lucknow 226001, India
b Drug Target Discovery and Development Division, Central Drug Research Institute, CSIR, Lucknow 226001, India
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 25 January 2010
Received in revised
form 9 April 2010
Accepted 14 April 2010
Available online 20 April 2010
A series of eighty one 2,4,6-trisubstituted-1,3,5-triazines were synthesized and evaluated in vitro for the
growth inhibition of Mycobacterium tuberculosis H37Rv. Fifteen compounds from this series exhibited
good to moderate activity with an MIC in the range 1.56e3.12 mg/mL and most of them were found to be
nontoxic against VERO cells and MBMDMQs (mouse bone marrow derived macrophages). This is for the
first time that 2,4,6-trisubstituted-1,3,5-triazines were identified as a potent inhibitors of M. tuberculosis
H37Rv.
Ó 2010 Elsevier Masson SAS. All rights reserved.
Keywords:
1,3,5-Triazine
Pyrimidine
Isoniazid
Anti-tubercular
1. Introduction
Dihydrofolate reductase (DHFR) is a key enzyme of folate bio-
cycle [6] and also a prime target for infectious diseases [7]. DHFR
Tuberculosis (TB) is a chronic infectious disease caused by
Mycobacterium tuberculosis, which is responsible for the deaths of
about 1 billion people during the last two centuries [1]. According
to the World Health Organization (WHO), 2 million people die
every year and at least 9 million are getting infected with this
infection [2]. In addition, the evolution of its new virulent forms
like multidrug resistant (MDR-TB) and extensively drug resistant
(XDR-TB) has become a major threat to the humankind [1]. The
present chemotherapy DOTS (directly observed treatment short-
course) has a cure rate of up to 95% if patient gives compliance.
Despite the fact that it is treatable and preventable, the disease has
been spreading at a steady rate due to the length of the therapy,
that makes patient compliance difficult and noncompliance is
a frequent source for multidrug resistant strains (MDR-TB). Espe-
cially, the resurgence in TB is alarming due to the development of
pathogenic synergy with HIV [3,4]. In developing countries, the
prevalence of MDR-TB was reported to be as high as 50% due to
inadequate supply of the drugs as a consequence of poor financial
resources [5]. Thus the above mentioned factors reveal the neces-
sity to develop effective and affordable anti-tubercular agents.
catalyzes the dihydrofolate to tetrahydrofolate, the folate cofactor
involved in the DNA replication as well as for the synthesis and/or
catabolism of several amino acids (Met, Gly, Ser, Glu, His). There-
fore, the inhibition of DHFR enzyme hampers the biosynthesis of
DNA which leads to the inhibition of cells proliferation [8,9]. In
addition, this enzyme has high binding affinities and selectivity
towards the substrate analogues that are not readily displaced by
the natural substrates [10]. This made the DHFR as an ideal target
for rational and efficient drug design for anti-infective agents.
Moreover, the enzyme is thoroughly explored for the development
of antibacterial agents after the discovery of trimethoprim (TMP).
TMP is used as a synergiser [11] due to its good DHFR binding
selectivity [12e14]. Therefore, antifolates targeting the DHFR
represent a validating approach for the development of anti-
mycobacterial agents due to their well established mode of actions
[15] and a higher degree of selectivity for the microbial enzymes
than the human enzymes [14,16,17].
In search of such folate antagonists, Gangjee et al. synthesized
tricyclic tetrahydropyrido furo[2,3-d]pyrimidines and found
benzoyl-
L-glutamic acid derivative potent against Mycobacterium
avium DHFR [18]. Similarly, Rosowsky et al. synthesized 2,4-dia-
minopteridine analogues with a bridged diarylamine side chain
and found that the compound having seven-membered ring in the
dibenz[b,f]azepine moiety was more selective and most active
* 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 2010 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2010.04.017

3336
N. Sunduru et al. / European Journal of Medicinal Chemistry 45 (2010) 3335e3345
against M. avium DHFR [19]. With the same motivation, Shoen et al.
synthesized 2,4-diamino-5-methyl-5-deazapteridines (DMDP)
having structures similar to the trimetrexate/piritrexim and iden-
tified their antimycobacterial activity against M. avium complex
(MAC) [20], in the continuation Suling et al. established the DMDPs
activity and selectivity towards the DHFR of MAC/Human [21].
Additionally, Meyer et al. [22] and Gerum et al. [23] also identified
WR99210 (1,3,5-triazine derivative) and its analogues as potent
inhibitors of MAC and M. tuberculosis DHFR, respectively. While El-
Hamamsy et al. [24] verified the activity and selectivity of
substituted 2,4-diaminopyrimidines against DHFR of M. tubercu-
losis. Moreover DHFR is also a target for anti-tubercular drug
isoniazid [25]. Therefore, folate antagonists represent a premier
class for the development of antimycobacterial agents.
In this context, we would like to mention our continuous efforts
devoted to the synthesis of novel heterocycles as anti-infective
agents. We earlier reported the antiparasitic activity of substituted
pyrimidines and triazines [26e36]. Here, we report the excellent
anti-tubercular activity of easily synthesizable 2,4,6-trisubsti-
tuted-1,3,5-triazine derivatives, using the hits obtained from the
pyrimidino-triazine derivatives (1e22) which were previously
reported for their anti-leishmanial activity, along with some
substituted pyrimidines (23e29) by our group [37] (Fig. 1). These
pyrimidino-triazine compounds were found to have moderate anti-
tubercular activity, while substituted pyrimidines showed deprived
activity. This confirms that hybrids may be active due to the
presence of 1,3,5-triazine moiety and thus we initiated the explo-
ration of 2,4,6-trisubstituted-1,3,5-triazines for their anti-tuber-
cular activity. For this purpose, we initially synthesized a series of
triazines monosubstituted with 1,2,3,4-tetrahydroquinoline
(48e55), piperidine (56e63) and disubstituted with 1,2,3,4-tetra-
hydroquinoline/tetrahydroisoquinoline (36e47), which have
shown moderate anti-tubercular activity. So, in an effort to increase
the activity, we have developed a novel series by incorporating
isoniazid with 1,3,5-triazine moiety (64e87) and found them with
a promising anti-tubercular activity. In this manuscript, synthesis of
2,4,6-trisubstituted-1,3,5-triazines and their anti-tubercular
activity against M. tuberculosis H37Rv have been reported and also
it is for the first time that they have been identified as an anti-
mycobacterial agents (Fig. 2).
synthesized from the precursor cyanuric chloride (2,4,6-trichloro-
1,3,5-triazine) and the addition of amines (Table 1 and 2) was
carried out based on the strength and structure of nucleophile
(Scheme 1). The intermediates 2-chloro-4,6-substituted-[1,3,5]
triazine (30, 31) were obtained by reacting cyanuric chloride with
1,2,3,4-tetrahydroquinoline (THQ)/isoquinoline (THIQ) respectively
in the presence of K2CO3 in dry THF. These compounds were further
subjected to nucleophilic substitution with different amines to
obtain trisubstituted triazines having THQ (36e41) and THIQ
(42e47) at 2,4-positions. While the derivatives having mono-
substitution of tetrahydroquinoline (48e54), piperidine (57e63) at
2-position and different amines at 4,6-positions, were obtained
from their respective intermediates 32 and 34. Whereas
compounds 55, 56 were obtained by reacting 32 and 34 respec-
tively with 50% ethylamine solution in acetone. These intermedi-
ates, including 33 (THIQ) and 35 (aniline) were prepared by
reacting cyanuric chloride with respective amines in the presence
of K2CO3 in dry THF.
To synthesize the compounds with different substitutions at
2,4,6-positions of 1,3,5-triazine (64e87), the intermediates 32, 33,
34 and 35 were subjected to nucleophilic substitution with various
amines (Table 1, 2), followed by the isonicotinohydrazide in the
presence of K2CO3 in THF to furnish their respective compounds.
All the synthesized compounds were well characterized by IR,
Mass, NMR and the purity was established with elemental
analysis.
3. Biological activities
3.1. In vitro anti-tubercular assay
Evaluation of anti-tubercular activity against M. tuberculosis
H37Rv was carried out with a recommended protocol [38] using
Middlebrook (MB) 7H10 agar medium. A 100 mL of serial two fold
dilutions of the stock (1.0 mg/mL in DMSO, Dimethyl Sulphoxide) of
test compounds and standard anti-tubercular drug {isoniazid
(INH)} were incorporated in the medium (final volume, 2 mL/tube)
supplemented with OADC (oleic acid, albumin fraction IV, dextrose
and catalase). Compounds/drug containing tubes were kept in
slanting position till the medium solidified. Culture of M. tubercu-
losis H37Rv grown on LowensteineJensen (LeJ) was harvested in N-
saline containing 0.05% Tween-80. The culture was vigorously
agitated with glass beads to make a single cell suspension. A
2. Chemistry
working inoculum (2 ꢀ 107 cfu/mL; 10
mL/tube) of mycobacterium
Our synthetic approach towards the targeted compounds is
concerned with inexpensive chemicals and easily accessible
conversions in good yield. 2,4,6-trisubstituted triazines were
was spread on the surface of the medium and the tubes were kept
at 37 ꢁC for 4 weeks for the appearance of colonies. Tubes con-
taining no drug served as control. The minimum concentration of
the drug (INH)/compounds that completely inhibited the growth of
mycobacterium was recorded as Minimum Inhibitory Concentra-
tion (MIC) with respect to the used inoculum.
OCH3
H3CO
SCH3
3.2. Cytotoxicity evaluation
R1
N
N
N
3.2.1. Evaluation against VERO cells
Cell line was procured from laboratory animal division of CDRI.
The cell suspension was plated in 96-well tissue culture plates at
OCH3
H3CO
H3CO
NH
a density of 20,000 cells per well (in 100 mL) in minimal essential
R2
N
medium (MEM) with antibiotics þ 10% fetal bovine serum (FBS).
The monolayers were then incubated overnight at 37 ꢁC and 5% CO2
for allowing adherence of cells. Compounds of different concen-
trations were added in MEM þ 10% FBS. As a positive control,
a known toxic compound was used. DMSO was used as negative
N
N
R2
N
R2
NH2
1-11 (R1= OCH3)
12-22 (R1= H)
23-29
control. After 24 h incubation, 20 mL of MTS solution (tetrazolium
compound, Owen’s reagent) was added to each well and incubated
Fig. 1. Pyrimidino-triazines and pyrimidines with anti-leishmanial and anti-tubercular
activity.
for 2 h at 37 ꢁC, 5% CO2. Reading was taken at 490 nm using a plate

N. Sunduru et al. / European Journal of Medicinal Chemistry 45 (2010) 3335e3345
3337
O
H
N
R1
N
R2
N
R1
N
N
H
N
N
N
N
N
N
N
R2
R1
R2
R1
R2
64-87
48-63
36-47
R1 = 1,2,3,4-tetrahydroquinoline,
1,2,3,4-tetrahydroisoquinoline,
piperidine, aniline
R1 = 1,2,3,4-tetrahydroquinoline,
1,2,3,4-tetrahydroisoquinoline
R2 = Various amines
R1 = 1,2,3,4-tetrahydroquinoline,
piperidine
R2 = Various amines
R2 = Various amines
Fig. 2. Novel 2,4,6-trisubstituted-1,3,5-triazines with anti-tubercular activity.
reader. Absorbance shown by DMSO containing wells is taken as
100% survivors [39]. A compound is considered toxic if it causes 50%
inhibition at concentration 10 fold higher than its MIC.
washed twice and plated in 96-well tissue culture plates at
a concentration of 105 cells per well (100
mL) in supplemented
DMEM. The monolayers were then incubated at 37 ꢁC in 5% CO2
with the medium change every 3rd day. Macrophages were used 5
days later. Different concentrations of compounds were added in
antibiotic free, FBS supplemented, DMEM and incubated at 37 ꢁC in
3.2.2. Evaluation against mouse bone marrow derived
macrophages (MBMDMQs)
Mouse was euthenized by exposure to CO2 and the femur bones
were dissected out. The bones were trimmed at each end, and the
marrow was flushed out (using 26-gauge needle) with 5 ml of
Dulbecco’s minimal essential medium (DMEM) supplemented with
10% FBS, 15% L-929 fibroblast conditioned supernatant (prepared as
described below), and non essential amino acids. Cells were
5% CO2. After 48 h, 20 mL of MTS solution was added to each well
and incubated for 2 h at 37 ꢁC in 5% CO2. Reading was taken at
490 nm using a plate reader. Absorbance shown by DMSO con-
taining wells is taken as 100% survivors [40]. A compound is
considered toxic if it causes 50% inhibition at concentration 10 fold
higher than its MIC.
Table 1
In vitro anti-tubercular and cytotoxic activities of targeted compoundsa.
Compounds
R1
R2
MIC (
m
g/mL)
Cytotoxicity
VERO
MTB-H37Rv
MBMDMQ
1
2
5
6
7
10
11
14
15
16
21
22
42
45
57
58
64
65
66
67
69
70
71
72
73
74
75
76
77
78
79
81
methoxy
methoxy
methoxy
methoxy
methoxy
methoxy
methoxy
hydrogen
hydrogen
hydrogen
hydrogen
hydrogen
tetrahydroisoquinoline
tetrahydroisoquinoline
piperidine
2-aminoethylmorpholine
3-aminopropylmorpholine
t-butylamine
12.5
12.5
3.12
6.25
12.5
3.12
12.5
6.25
6.25
6.25
12.5
12.5
3.12
6.25
12.5
12.5
6.25
3.12
3.12
3.12
3.12
3.12
3.12
3.12
3.12
3.12
3.12
6.25
3.12
6.25
1.56
6.25
6.25
6.25
0.025
ND
ND
NT
ND
ND
T
ND
ND
T
ND
ND
T
piperidine
N-methylpiperazine
isopropylamine
N-ethylpiperazine
N,N-diethylethylenediamine
N,N-dimethylethylenediamine
t-butylamine
isopropylamine
N-ethylpiperazine
2-aminoethylmorpholine
N-methylpiperazine
n-propylamine
isopropylamine
n-butylamine
t-butylamine
isopropylamine
morpholine
piperidine
n-butylamine
t-butylamine
isopropylamine
tetrahydroisoquinoline
2-aminopyrimidine
n-butylamine
t-butylamine
isopropylamine
piperidine
morpholine
cyclohexylamine
n-butylamine
ND
ND
ND
ND
ND
ND
NT
ND
ND
ND
ND
NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
ND
NT
ND
NT
ND
ND
ND
NT
ND
ND
ND
ND
ND
ND
T
ND
ND
ND
ND
NT
NT
NT
T
piperidine
tetrahydroquinoline
tetrahydroquinoline
tetrahydroquinoline
tetrahydroquinoline
tetrahydroisoquinoline
tetrahydroisoquinoline
tetrahydroisoquinoline
tetrahydroisoquinoline
tetrahydroisoquinoline
piperidine
piperidine
piperidine
piperidine
piperidine
aniline
aniline
aniline
aniline
NT
T
NT
T
NT
NT
ND
NT
ND
NT
ND
ND
ND
NT
84
86
isopropylamine
Isoniazid (INH)
a
MTB: Mycobacterium tuberculosis; MBMDMQ: mouse bone marrow derived macrophages; NT: nontoxic; T: Toxic (A compound is considered toxic if it causes 50%
inhibition at concentration 10 fold higher than its MIC); ND: not done.

3338
N. Sunduru et al. / European Journal of Medicinal Chemistry 45 (2010) 3335e3345
Table 2
R1
N
R2
R1
N
Cl
In vitro anti-tubercular activity of rest of the synthesized compounds against M.
tuberculosis H37Rv.
c
N
N
N
N
Compounds R1
R2
MIC
g/mL)
R1
R1
a
(
m
36-41 (R1= THQ)
42-47 (R1= THIQ)
30 R1= THQ
31 R1= THIQ
3
methoxy
N,N-diethylethylenediamine
n-butylamine
n-propylamine
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
4
methoxy
8
methoxy
Cl
N
Cl
9
methoxy
morpholine
12
13
17
18
19
20
23
24
25
26
27
28
29
36
37
38
39
40
41
43
44
46
47
48
49
50
51
52
53
54
55
56
59
60
61
62
63
68
80
82
83
85
87
hydrogen
hydrogen
hydrogen
hydrogen
hydrogen
hydrogen
methoxy
methoxy
methoxy
methoxy
methoxy
methoxy
2-aminoethylmorpholine
3-aminopropylmorpholine
piperidine
N-methylpiperazine
n-propylamine
N
N
R1
N
R2
Cl
N
N
d
morpholine
R2
2-aminoethylmorpholine
3-aminopropylmorpholine
N,N-diethylethylenediamine
n-butylamine
piperidine
N-methylpiperazine
morpholine
2-aminoethylmorpholine
3-aminopropylmorpholine
t-butylamine
N-methylpiperazine
N,N-diethylethylenediamine
morpholine
b
48-55 (R1= THQ)
R1
N
Cl
56-63 (R1= Piperidine)
N
N
O
H
R1
N
N
Cl
32 R1= THQ
N
methoxy
H
N
N
N
tetrahydroquinoline
tetrahydroquinoline
tetrahydroquinoline
tetrahydroquinoline
tetrahydroquinoline
tetrahydroquinoline
tetrahydroisoquinoline 3-aminopropylmorpholine
tetrahydroisoquinoline t-butylamine
tetrahydroisoquinoline N,N-diethylethylenediamine
tetrahydroisoquinoline morpholine
tetrahydroquinoline
tetrahydroquinoline
tetrahydroquinoline
tetrahydroquinoline
tetrahydroquinoline
tetrahydroquinoline
tetrahydroquinoline
tetrahydroquinoline
piperidine
piperidine
piperidine
piperidine
piperidine
piperidine
tetrahydroquinoline
aniline
aniline
aniline
33 R1= THIQ
e
R2
34 R1= Piperidine
35 R1= Aniline
64-68 (R1= THQ)
69-73 (R1= THIQ)
74-78 (R1= Piperidine)
79-87 (R1= Aniline)
Scheme 1. Reagents and conditions: (a) 1,2,3,4-Tetrahydroquinoline (for 30) and
1,2,3,4-Tetrahydroisoquinoline (for 31), K2CO3, THF, 0e60 ꢁC, 4 h; (b) Respective amines,
K2CO3, THF, 0 ꢁCert, 3 h; (c) Different amines, K2CO3, THF, reflux, 8 h; (d) Different
amines, K2CO3, THF, reflux, 7e8 h; 50% ethylamine sol., Acetone, reflux, 8 h (for 55, 56);
(e) i. Different amines, K2CO3, THF, rt, 2 h; ii. Isonicotinohydrazide, reflux, 8 h.
n-propylamine
isopropylamine
3-aminopropylmorpholine
t-butylamine
N,N-diethylethylenediamine
N,N-dimethylethylenediamine >12.5
2-aminoethylmorpholine
ethylamine
ethylamine
t-butylamine
2-aminoethylmorpholine
3-aminopropylmorpholine
N,N-dimethylethylenediamine >12.5
N,N-diethylethylenediamine
3-aminopropylmorpholine
piperidine
3-aminopropylmorpholine
aniline
observation confirmed that the antimycobacterial activity of pyr-
imidino-triazine derivatives is majorly due to the presence of
1,3,5-triazine moiety. Therefore, in order to explore the structur-
eeactivity relationship of 2,4,6-trisubstituted-1,3,5-triazines,
triazines monosubstituted with 1,2,3,4-tetrahydroquinoline
(48e55), piperidine (56e63), isoniazid (64e87) and disubstituted
with tetrahydroquinoline (36e41), tetrahydroisoquinoline (42e47)
were synthesized.
Among all the above synthesized compounds, those having
substitution of isonicotinohydrazide (INH) at 6-position of 1,3,5-
triazine (64e87) were found to be more promising anti-tubercular
candidates when compared to others. Compound 64 having 1,2,3,4-
tetrahydroquinoline as R1 and n-butylamine as R2 showed MIC of
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
>12.5
aniline
aniline
t-butylamine
isonicotinohydrazide
6.25
isopropylamine (66) and morpholine (67) as R2 have shown equal
potency of 3.12 g/mL and nontoxic against both the VERO and the
mg/mL, while compounds with same R1 and t-butylamine (65),
4. Results and discussion
m
MBMDMQs. Surprisingly, irrespective of substitution of R2 and
having 1,2,3,4-tetrahydroisoquinoline as R1, compounds (69e73)
have shown equal potency of 3.12 mg/mL, but compounds 69, 71
and 73 were found to be toxic against MBMDMQs. Compounds 74,
75 and 77 having piperidine as R1 and 2-aminopyrimidine,
n-butylamine, and isopropylamine as R2 respectively, showed MIC
Out of eighty one compounds screened for their in vitro anti-
tubercular activity against M. tuberculosis H37Rv, thirty four
compounds were found active with MIC in the range of
12.5e1.56
mg/mL (Table 1) and the rest were with MIC >12.5
mg/mL
(Table 2). The compounds with potent MIC of 3.12, 1.56
mg/mL were
also tested for their cytotoxicity against VERO cells and MBMDMQs
(mouse bone marrow derived macrophages) and most of them
were found to be nontoxic. In pyrimidino-triazine derivatives,
compounds 5 and 10 having methoxy group as R1 (similar to that of
trimethoprim) and t-butylamine, isopropylamine respectively as
of 3.12 mg/mL and were nontoxic. Compound 79, having aniline as
R1 and morpholine as R2 was found to be the most active amongst
these analogues with nontoxic profile. The activity profile of these
compounds clearly suggests that the isonicotinohydrazide has
promoted the anti-tubercular activity of 1,3,5-triazines.
R2, showed MIC of 3.12
analogues 16 and 21 have shown decreased activity with an MIC of
6.25, 12.5 g/mL respectively. Similarly, trimethoxyphenyl deriva-
mg/mL, while their dimethoxyphenyl
m
5. Conclusions
tives 1, 2, 6 and 7 have shown more potency in comparison to their
dimethoxyphenyl derivatives. Moreover, compound 5 was found
to be nontoxic against VERO cells, which lead to the synthesis of
trimethoxyphenyl substituted pyrimidines derivatives (23e29).
Development of antimycobacterial agents based on identified
targets and their mechanisms of action is a productive approach for
the lead generation. In this perception, we have chosen to explore
1,3,5-triazine moiety known to be targeting DHFR enzyme, which
These compounds showed MIC more than 12.5
mg/mL. This

N. Sunduru et al. / European Journal of Medicinal Chemistry 45 (2010) 3335e3345
3339
was also identified as a prime target for anti-tubercular drug
Isoniazid. With this aim, we designed and synthesized easily
accessible 2,4,6-trisubstituted-1,3,5-triazines and a systematic SAR
study was carried out. Activity results suggest that the incorpora-
tion of anti-tubercular drug INH increased the potency of 1,3,5-
triazines. Thus our studies reveal that these 1,3,5-triazines are
novel anti-tubercular agents and can be proved as potential drug
candidates. This calls for the further exploration of SAR of these
compounds to understand the mechanistic aspects and to develop
them as drugs in our fight against tuberculosis.
170.16, 163.98, 134.07, 131.86, 128.55, 127.19, 126.83, 126.46, 46.26,
42.31, 28.49. Anal. Calcd for C21H20ClN5: C, 66.75; H, 5.33; N, 18.53;
Found: C, 66.59; H, 5.30; N, 18.46.
6.2. General procedure for the synthesis of compounds 32e35
To the solution of cyanuric chloride (2,4,6-trichloro-1,3,5-tri-
azene) (1.2 equiv) and K2CO3 (1 equiv) in dry THF, 1,2,3,4-tetrahy-
droquinoline (1 equiv) in dry THF was added dropwise at 0 ꢁC
during 1 h and continued to stir for 2 more hours at room
temperature. After the completion of reaction, the mixture was
evaporated to dryness and purified with flash column chromatog-
raphy using chloroform to methanol gradient elution to afford
compound 32. Same method was applied to obtain intermediates
33, 34 and 35 using tetrahydroisoquinoline, piperidine and aniline
respectively.
6. Experimental
IR spectra were recorded on Beckman Aculab-10, Perkin Elmer
881 and FTIR 8210 PC, Schimadzu spectrophotometers either on
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. The
samples (dissolved in suitable solvents such as methanol/acetoni-
trile/water) were introduced into the ESI source through a syringe
6.2.1. 1-(4,6-Dichloro-1,3,5-triazin-2-yl)-1,2,3,4-
tetrahydroquinoline (32)
Yield: 76%; mp 126e129 ꢁC; FAB-MS: 280 (M þ 1); IR (KBr) 3039,
pump at the rate of 5
ml per min. The ESI capillary was set at 3.5 kV
1608, 1561, 1473, 1330, 1316, 1233, 1172, 1027, 833 cmꢂ1 1H NMR
;
and the cone voltage was 40 V. The spectra were collected in 6s
scans and the print outs are averaged spectra of 6e8 scans. In case
of multiplets the signals are reported as intervals. Signals were
abbreviated as s, singlet; d, doublet; t, triplet; m, multiplet. The
electron spray mass spectra were recorded on triple quadrupole
mass spectrometer. EI mass spectra were recorded on JEOL JMS-D-
300 spectrometer with the ionization potential of 70 eV and ES
mass on Quantro-II, micro mass. Purity of all tested compounds was
ascertained on the basis of their elemental analysis and was carried
out on Carlo-Erba-1108 instrument. The melting points were
recorded on an electrically heated melting point apparatus and are
uncorrected.
(200 MHz, CDCl3):
d
(ppm) 7.74 (d, 1H, J ¼ 7.63 Hz), 7.30e7.12 (m,
3H), 4.05 (t, 2H, J ¼ 6.44 Hz), 2.82 (t, 2H, J ¼ 6.47 Hz), 2.13e1.96 (m,
2H); 13C NMR (75 MHz, CDCl3): 170.37, 163.97, 136.58, 131.61,
128.48, 125.91, 125.22, 124.23, 45.33, 26.78, 23.46; Anal. Calcd for
C12H10Cl2N4: C, 51.27; H, 3.59; N, 19.93; Found: C, 51.19; H, 3.54; N,
19.82.
6.2.2. 2-(4,6-Dichloro-1,3,5-triazin-2-yl)-1,2,3,4-
tetrahydroisoquinoline (33)
Yield: 80%; mp 73e75 ꢁC; ESMS: 281 (M þ 1); IR (KBr): 2854,
1561,1464, 780 cmꢂ1; 1H NMR (200 MHz, CDCl3):
d (ppm) 7.29e7.18
(m, 4H), 4.82 (s, 2H), 3.89 (m, 2H), 2.85 (m, 2H); 13C (50 MHz,
CDCl3): 167.84, 165.37, 135.62, 131.75, 129.58, 128.82, 124.74, 48.78,
44.14, 31.69; Anal. Calcd for C12H10Cl2N4: C, 51.27; H, 3.59; N, 19.93;
Found: C, 51.12; H, 3.45; N, 19.98.
6.1. General procedure for the synthesis of compounds 30 and 31
The solution of 1,2,3,4-tetrahydroquinoline/1,2,3,4-tetrahy-
droisoquinoline (1 equiv) in dry THF was added dropwise to an ice-
cold mixture of cyanuric chloride (1.5 equiv) and K2CO3 (2 equiv) in
dry THF during 30 min. The reaction mixture was stirred at room
temperature for 1 h and then stirred mechanically at 60 ꢁC for 3 h.
The reaction mixture was filtered and solvent was evaporated
under vacuum to dryness. The solid mass was dissolved in CHCl3,
washed with water and dried over anhydrous Na2SO4, concentrated
and purified with flash column chromatography using hexane to
ethyl acetate gradient elution to afford compounds 30 and 31
respectively.
6.2.3. 2,4-Dichloro-6-(piperidin-1-yl)-1,3,5-triazine (34)
Yield: 84%; mp 142e143 ꢁC; ESMS: 233 (M þ 1); IR (KBr) 2945,
1574, 1472, 1217, 765 cmꢂ1; 1H NMR (200 MHz, CDCl3):
d (ppm) 3.81
(t, 4H, J ¼ 5.18 Hz), 1.68e1.59 (m, 6H); 13C NMR (50 MHz, CDCl3):
170.54, 164.43, 45.74, 26.06, 24.63; Anal. Calcd for C8H10Cl2N4: C,
41.22; H, 4.32; N, 24.04; Found: C, 41.26; H, 4.29; N, 24.11.
6.2.4. 4,6-Dichloro-N-phenyl-1,3,5-triazin-2-amine (35)
Yield: 85%; mp 219e221 ꢁC; ESMS: 241 (M þ 1); IR (KBr): 3426,
1554, 1465, 750 cmꢂ1; 1H NMR (200 MHz, CDCl3):
d (ppm) 9.12 (bs,
1H), 7.67 (m, 2H), 7.22 (m, 1H), 6.89 (m, 2H); 13C (50 MHz, CDCl3):
168.92, 166.76, 138.63, 128.18, 122.34, 119.81; Anal. Calcd for
C9H6Cl2N4: Calculated C: 44.84; H: 2.51; N: 23.24; Found: C: 44.76;
H: 2.52; N: 23.18.
6.1.1. 1,10-(6-Chloro-1,3,5-triazine-2,4-diyl)bis(1,2,3,4-
tetrahydroquinoline) (30)
Yield: 78%; mp 138e140 ꢁC; FAB-MS: 378 (M þ 1); IR (KBr) 3025,
1608, 1555, 1479, 1339, 1318, 1233, 1175, 1036, 837 cmꢂ1 1H NMR
;
(200 MHz, CDCl3):
d
(ppm) 7.72 (d, 2H, J ¼ 7.87 Hz), 7.28e7.11 (m,
6.3. General procedure for the synthesis of compounds 36e41
6H), 4.06 (t, 4H, J ¼ 6.29 Hz), 2.82 (t, 4H, J ¼ 6.68 Hz), 2.11e1.98 (m,
4H); 13C NMR (75 MHz, CDCl3): 170.39, 163.97, 136.68, 131.65,
128.52, 125.91, 125.25, 124.23, 45.35, 26.80, 23.52; Anal. Calcd for
C21H20ClN5: C, 66.75; H, 5.33; N, 18.53; Found: C, 66.53; H, 5.19; N,
18.51.
The mixture of compound 30 (1 equiv), different amines
(1.2 equiv) and K2CO3 (1.2 equiv) in dry THF was refluxed for 8 h.
The reaction mixture was filtered and the filtrate was evaporated
under vacuum. The obtained solid residue was purified with flash
column chromatography using chloroform to methanol gradient
elution to afford the targeted compounds 36e41.
6.1.2. 2,20-(6-Chloro-1,3,5-triazine-2,4-diyl)bis(1,2,3,4-
tetrahydroisoquinoline) (31)
Yield: 83%; mp 130e132 ꢁC; FAB-MS: 378 (M þ 1); IR (KBr) 3010,
6.3.1. 4,6-bis(3,4-dihydroquinolin-1(2H)-yl)-N-(2-
morpholinoethyl)-1,3,5-triazin-2-amine (36)
1557, 1474, 1373, 1349, 1232, 1154, 1043, 843 cmꢂ1 1H NMR
;
(300 MHz, CDCl3):
d
(ppm) 7.25e7.20 (m, 8H), 4.95 (s, 4H), 4.09 (t,
Yield: 68%; mp 96e98 ꢁC; FAB-MS: 472 (M þ 1); IR (KBr) 3425,
4H, J ¼ 5.62 Hz), 2.99 (t, 4H, J ¼ 5.58 Hz). 13C NMR (75 MHz, CDCl3):
2943, 2815, 1593, 1428, 1352, 1118, 862, 759 cmꢂ1 1H NMR
;

3340
N. Sunduru et al. / European Journal of Medicinal Chemistry 45 (2010) 3335e3345
(200 MHz, CDCl3):
d
(ppm) 7.84 (d, 2H, J ¼ 8.12 Hz), 7.15e6.97 (m,
6.4. General procedure for the synthesis of compounds 42e47
6H), 5.34 (bs, 1H), 4.00 (t, 4H, J ¼ 5.59 Hz), 3.68 (t, 4H, J ¼ 4.49 Hz),
3.45 (t, 4H, J ¼ 5.93 Hz), 2.77 (t, 4H, J ¼ 6.59 Hz), 2.53e2.42 (m, 4H),
2.00e1.88 (m, 4H); 13C NMR (50 MHz, CDCl3): 166.34, 165.36,
139.87, 131.12, 128.90, 126.33, 125.17, 123.45, 67.31, 58.01, 53.84,
44.45, 37.41, 27.79, 24.22; Anal. Calcd for C27H33N7O: C, 68.76; H,
7.05; N, 20.79; Found: C, 68.59; H, 6.98; N, 20.84.
The mixture of compound 31 (1 equiv), different amines
(1.2 equiv) and K2CO3 (1.2 equiv) in dry THF was refluxed for 8 h.
The reaction mixture was filtered and the filtrate was evaporated
under vacuum. The solid residue was purified with flash column
chromatography using chloroform to methanol gradient elution to
obtain the targeted compounds 42e47.
6.3.2. 4,6-bis(3,4-dihydroquinolin-1(2H)-yl)-N-(3-
morpholinopropyl)-1,3,5-triazin-2-amine (37)
6.4.1. 4,6-bis(3,4-Dihydroisoquinolin-2(1H)-yl)-N-(2-
morpholinoethyl)-1,3,5-triazin-2-amine (42)
Yield: 62%; mp 115e118 ꢁC; FAB-MS: 486 (M þ 1); IR (KBr) 3259,
2956, 2813,1578,1444,1309,1117, 882, 752cmꢂ1; 1H NMR(200 MHz,
Yield: 67%; mp 104e105 ꢁC; FAB-MS: 472 (M þ 1); IR (KBr) 3429,
CDCl3):
d
(ppm) 7.81 (d, 2H, J ¼ 8.12 Hz), 7.19e7.05 (m, 6H), 5.49 (bs,
2928, 2854,1540,1444,1360,1113, 806, 746cmꢂ1;1HNMR(200MHz,
CDCl3): d (ppm) 7.14e7.05 (m, 8H), 5.32 (bs, 1H), 4.81 (s, 4H), 3.92 (t,
4H, J ¼ 5.09 Hz), 3.62 (t, 4H, J ¼ 4.53 Hz), 3.45e3.42 (m, 2H), 2.80 (t,
4H, J ¼ 5.13 Hz), 2.48e2.38 (m, 6H).13C NMR (50MHz, CDCl3): 166.46,
165.42, 136.30, 134.88, 129.16, 126.91, 126.64, 126.53, 67.35, 58.22,
53.98, 45.99, 41.23, 37.60, 29.47. Anal. Calcd for C27H33N7O: C, 68.76;
H, 7.05; N, 20.79. Found: C, 68.61; H, 7.12; N, 20.84.
1H), 4.00 (t, 4H, J ¼ 5.63 Hz), 3.71 (t, 4H, J ¼ 4.45 Hz), 3.45 (t, 4H,
J ¼ 5.90 Hz), 2.79 (t, 4H, J ¼ 5.84 Hz), 2.49e2.41 (m, 4H), 2.02e1.99
(m, 4H),1.80e1.67 (m, 2H); 13C NMR (50 MHz, CDCl3): 169.20,165.93,
138.57, 131.96, 128.98, 126.07, 125.52, 124.80, 67.35, 57.24, 54.13,
45.08, 40.23, 27.50, 26.18, 24.08; Anal. Calcd for C28H35N7O: C, 69.25;
H, 7.26; N, 20.19; Found: C, 69.38; H, 7.22; N, 20.07.
6.3.3. N-tert-Butyl-4,6-bis(3,4-dihydroquinolin-1(2H)-yl)-1,3,5-
triazin-2-amine (38)
6.4.2. 4,6-bis(3,4-Dihydroisoquinolin-2(1H)-yl)-N-(3-
morpholinopropyl)-1,3,5-triazin-2-amine (43)
Yield: 73%; mp 99e102 ꢁC; FAB-MS: 415 (M þ 1); IR (KBr) 3350,
Yield: 65%; mp 102e105 ꢁC; FAB-MS: 486 (M þ 1); IR (KBr) 3358,
2957, 2833, 1572, 1436, 1399, 1112, 871, 755 cmꢂ1
;
1H NMR
2929, 2852, 1585, 1492, 1446, 1359, 1115, 931, 750 cmꢂ1 1H NMR
;
(200 MHz, CDCl3):
d
(ppm) 7.73 (d, 2H, J ¼ 7.80 Hz), 7.17e7.05 (m,
(200 MHz, CDCl3): d (ppm) 7.16e7.05 (m, 8H), 5.47 (bs, 1H), 4.81 (s,
6H), 5.31 (bs, 1H), 4.01 (t, 4H, J ¼ 6.01 Hz), 2.78 (t, 4H, J ¼ 6.52 Hz),
2.00 (t, 4H, J ¼ 6.19 Hz), 1.37 (s, 9H); 13C NMR (50 MHz, CDCl3):
169.04, 165.08, 138.54, 132.15, 128.76, 126.46, 125.68, 124.90, 45.39,
29.16, 27.45, 24.18; Anal. Calcd for C25H30N6: C, 72.43; H, 7.29; N,
20.27; Found: C, 72.36; H, 7.26; N, 20.22.
4H), 3.93 (t, 4H, J ¼ 5.51 Hz), 3.64 (t, 4H, J ¼ 4.45 Hz), 3.44e3.35 (m,
2H), 2.79 (t, 4H, J ¼ 5.48 Hz), 2.36e2.33 (m, 6H), 1.74e1.60 (m, 2H);
13C NMR (50 MHz, CDCl3): 166.04, 165.01, 135.20, 133.39, 129.13,
126.88, 126.88, 126.59, 126.48, 67.43, 57.57, 54.15, 45.95, 41.17,
40.04, 29.43, 26.81; Anal. Calcd for C28H35N7O: C, 69.25; H, 7.26; N,
20.19; Found: C, 69.17; H, 7.13; N, 20.11.
6.3.4. 1,10-(6-(4-Methylpiperazin-1-yl)-1,3,5-triazine-2,4-diyl)bis
(1,2,3,4-tetrahydroquinoline) (39)
6.4.3. N-tert-Butyl-4,6-bis(3,4-dihydroisoquinolin-2(1H)-yl)-1,3,5-
triazin-2-amine (44)
Yield: 72%; semisolid; FAB-MS: 442 (M þ 1); IR (Neat) 2935,
2849, 2792, 1543, 1487, 1366, 1174, 1004, 755 cmꢂ1
;
1H NMR
Yield: 69%; mp 108e110 ꢁC; FAB-MS: 415 (M þ 1); IR (KBr) 3425,
(200 MHz, CDCl3):
d
(ppm) 7.84 (d, 2H, J ¼ 7.99 Hz), 7.10e6.95 (m,
2967, 2927, 1577, 1450, 1365, 1226, 927, 745 cmꢂ1 1H NMR
;
6H), 4.01 (t, 4H, J ¼ 6.03 Hz), 3.78 (t, 4H, J ¼ 4.74 Hz), 2.78 (t, 4H,
J ¼ 6.59 Hz), 2.41 (t, 4H, J ¼ 4.88 Hz), 2.31 (s, 3H), 2.08e1.92 (m, 4H);
13C NMR (50 MHz, CDCl3): 166.34, 165.61, 140.14, 130.94, 128.82,
126.14, 125.05, 123.05, 55.40, 46.67, 44.50, 43.44, 27.96, 24.19; Anal.
Calcd for C26H31N7: C, 70.72; H, 7.08; N, 22.20; Found: C, 70.58; H,
7.19; N, 22.13.
(200 MHz, CDCl3): d (ppm) 7.19e7.17 (m, 8H), 5.33 (bs, 1H), 4.90 (s,
4H), 4.02 (t, 4H, J ¼ 5.80 Hz), 2.91 (t, 4H, J ¼ 5.69 Hz),1.47 (s, 9H); 13C
NMR (50 MHz, CDCl3): 168.99, 164.93, 164.62, 135.72, 133.50,
129.07, 126.88,126.60,126.47, 46.04, 41.32, 29.71, 29.40, 29.19; Anal.
Calcd for C25H30N6: C, 72.43; H, 7.29; N, 20.27. Found: C, 72.29; H,
7.24; N, 20.32.
6.3.5. N1-(4,6-bis(3,4-Dihydroquinolin-1(2H)-yl)-1,3,5-triazin-2-
yl)-N2,N2-diethylethane-1,2-diamine (40)
6.4.4. 2,20-(6-(4-Methylpiperazin-1-yl)-1,3,5-triazine-2,4-diyl)bis
(1,2,3,4-tetrahydroisoquinoline) (45)
Yield: 63%; mp 105e108 ꢁC; FAB-MS: 458 (M þ 1); IR (KBr) 3266,
Yield: 73%; mp 100e102 ꢁC; FAB-MS: 442 (M þ 1); IR (KBr) 3017,
3165, 2962, 2832, 1613, 1576, 1444, 1312, 1100, 886, 755 cmꢂ1
;
1H
2929, 2844, 2763, 1543, 1440, 1364, 1170, 1002, 805, 743 cmꢂ1 1H
;
NMR (200 MHz, CDCl3):
d
(ppm) 7.75 (d, 2H, J ¼ 7.99 Hz), 7.31e6.98
NMR (200 MHz, CDCl3): d (ppm) 7.19e7.12 (m, 8H), 4.90 (s, 4H), 4.02
(m, 6H), 5.56 (bs, 1H), 3.99 (t, 4H, J ¼ 5.87 Hz), 3.53 (m, 2H), 2.78 (t,
4H, J ¼ 6.48 Hz), 2.45 (m, 6H), 2.03e1.94 (m, 4H), 1.25 (m, 6H); 13C
NMR (50 MHz, CDCl3): 169.24, 166.10, 138.57, 131.97, 128.99, 126.05,
125.58, 124.80, 51.65, 47.04, 45.08, 38.72, 27.49, 24.09, 12.02; Anal.
Calcd for C27H35N7: C, 70.87; H, 7.71; N, 21.43; Found: C, 70.76; H,
7.64; N, 21.45.
(t, 4H, J ¼ 5.83 Hz), 3.87 (t, 4H, J ¼ 4.90 Hz), 2.88 (t, 4H, J ¼ 5.72 Hz),
2.48 (t, 4H, J ¼ 4.99 Hz), 2.36 (s, 3H). 13C NMR (50 MHz, CDCl3):
166.79, 165.66, 135.80, 135.01, 129.12, 126.90, 126.53, 126.44, 55.49,
46.74, 46.00, 43.50, 41.18, 29.49. Anal. Calcd for C26H31N7: C, 70.72;
H, 7.08; N, 22.20. Found: C, 70.79; H, 7.14; N, 22.04.
6.4.5. N1-(4,6-bis(3,4-Dihydroisoquinolin-2(1H)-yl)-1,3,5-triazin-
2-yl)-N2,N2-diethylethane-1,2-diamine (46)
6.3.6. 4-(4,6-bis(3,4-Dihydroquinolin-1(2H)-yl)-1,3,5-triazin-2-yl)
morpholine (41)
Yield: 61%; mp 94e96 ꢁC; FAB-MS: 458 (M þ 1); IR (KBr) 3441,
Yield: 73%; mp 134e136 ꢁC; FAB-MS: 429 (M þ 1); IR (KBr) 3074,
2967, 2874, 1578, 1441, 1368, 1236, 1040, 803, 744 cmꢂ1 1H NMR
;
2954, 2851, 1537, 1484, 1362, 1111, 855, 761 cmꢂ1
;
1H NMR
(200 MHz, CDCl3): d (ppm) 7.14e7.06 (m, 8H), 5.26 (bs, 1H), 4.80 (s,
(200 MHz, CDCl3):
d
(ppm) 7.81 (d, 2H, J ¼ 8.16 Hz), 7.10e6.96 (m,
4H), 3.92 (t, 4H, J ¼ 5.47 Hz), 3.47e3.38 (m, 2H), 2.77 (t, 4H,
6H), 4.00 (t, 4H, J ¼ 5.98 Hz), 3.72e3.71 (m, 8H), 2.78 (t, 4H,
J ¼ 6.54 Hz), 1.94 (m, 4H); 13C NMR (50 MHz, CDCl3): 165.79, 165.34,
140.04, 131.12, 128.90, 126.21, 125.12, 123.31, 67.29, 44.55, 44.13,
27.95, 24.23; Anal. Calcd for C25H28N6O: C, 70.07; H, 6.59; N, 19.61.
Found: C, 70.11; H, 6.52; N, 19.43.
J ¼ 5.51 Hz), 2.61e2.40 (m, 6H), 0.97 (t, 6H, J ¼ 7.14 Hz); 13C NMR
(50 MHz, CDCl3):
d (ppm) 166.66, 165.76, 135.70, 134.92, 129.10,
126.86, 126.55, 126.45, 54.46, 47.43, 45.95, 41.16, 38.79, 29.45,
12.24; Anal. Calcd for C27H35N7: C, 70.87; H, 7.71; N, 21.43; Found: C,
70.76; H, 7.74; N, 21.40.

N. Sunduru et al. / European Journal of Medicinal Chemistry 45 (2010) 3335e3345
3341
6.4.6. 4-(4,6-bis(3,4-Dihydroisoquinolin-2(1H)-yl)-1,3,5-triazin-2-
yl)morpholine (47)
Anal. Calcd for C26H40N8O2: C, 62.88; H, 8.12; N, 22.56; Found: C,
60.72; H, 8.07; N, 22.50.
Yield: 69%; mp 149e152 ꢁC; FAB-MS: 429 (M þ 1); IR (KBr) 3073,
2959, 2845, 1546, 1445, 1363, 1114, 804, 740 cmꢂ1
;
1H NMR
6.5.4. N2,N4-Di-tert-butyl-6-(3,4-dihydroquinolin-1(2H)-yl)-1,3,5-
triazine-2,4-diamine (51)
(200 MHz, CDCl3):
d (ppm) 7.19e7.13 (m, 8H), 4.90 (s, 4H), 4.02 (t,
4H, J ¼ 5.81 Hz), 3.81e3.72 (m, 8H), 2.88 (t, 4H, J ¼ 5.74 Hz); 13C
NMR (50 MHz, CDCl3): 165.84,165.59, 135.76, 134.92, 129.11,126.88,
126.55, 126.45, 67.40, 45.98, 44.17, 41.19, 29.44; Anal. Calcd for
C25H28N6O: C, 70.07; H, 6.59; N, 19.61; Found: C, 70.12; H, 6.51; N,
19.47.
Yield: 65%; mp 142e144 ꢁC; ESMS: 355 (M þ 1); IR (KBr) 3261,
3144, 2964, 1595, 1502, 1413, 1211, 1066, 753 cmꢂ1 1H NMR
;
(200 MHz, CDCl3):
d
(ppm) 7.74 (d, 1H, J ¼ 7.84 Hz), 7.16e6.98 (m,
3H), 5.03 (bs, 2H), 3.97 (m, 2H), 2.77 (t, 2H, J ¼ 6.65 Hz), 1.99e1.93
(m, 2H), 1.41 (s, 18H); 13C NMR (50 MHz, CDCl3): 164.87, 139.93,
131.36, 128.70, 126.47, 125.31, 123.45, 51.11, 44.69, 29.78, 27.76,
24.35; Anal. Calcd for C20H30N6: C, 67.76; H, 8.53; N, 23.71; Found:
C, 67.72; H, 8.45; N, 23.66.
6.5. General procedure for compound synthesis
(a) General procedure for the synthesis of compounds 48e54 and
57e63
0
6.5.5. N1,N1 -(6-(3,4-Dihydroquinolin-1(2H)-yl)-1,3,5-triazine-2,4-
diyl)bis(N2,N2-diethylethane-1,2-diamine) (52)
The mixture of compound 32 (1 equiv), different amines
(2.2 equiv) and K2CO3 (2.2 equiv) in dry THF was refluxed for 7e8 h.
The reaction mixture was filtered and the solvent was evaporated
to dryness under vacuum. The residue was purified with flash
column chromatography using chloroform to methanol gradient
elution to afford respective compounds 48e54. The same proce-
dure was carried out to synthesize compounds 57e63 from 34.
Yield: 63%; mp 97e99 ꢁC; ESMS: 441 (M þ 1); IR (KBr) 3263,
3161, 2961, 1614, 1575, 1482, 1309, 1203, 1100, 755 cmꢂ1 1H NMR
;
(200 MHz, CDCl3):
d
(ppm) 7.81 (d, 1H, J ¼ 7.81 Hz), 7.16e7.01 (m,
3H), 6.14 (bs, 2H), 4.03 (t, 2H, J ¼ 5.76 Hz), 3.56e3.42 (m, 4H),
2.79e2.51 (m, 14H), 2.02e1.97 (m, 2H), 1.01 (t, 12H, J ¼ 7.07 Hz); 13C
NMR (50 MHz, CDCl3): 169.36, 165.76, 138.62, 132.01, 129.06,
126.06, 125.59, 124.82, 51.84, 47.04, 45.10, 38.71, 27.51, 24.10, 11.97;
Anal. Calcd for C24H40N8: C, 65.42; H, 9.15; N, 25.43; Found: C,
65.38; H, 9.02; N, 25.37.
(b) General procedure for the synthesis of compounds 55 and 56
0
The mixture of compound 32 (1 equiv), 50% ethylamine aqueous
solution (10 equiv) in acetone was refluxed for 8 h. The reaction
mixture was evaporated to dryness under vacuum. The residue was
purified with flash column chromatography using chloroform to
methanol gradient elution to afford the targeted compound 55. The
same procedure was carried out to synthesize final compound 56
from the intermediate 34.
6.5.6. N1,N1 -(6-(3,4-Dihydroquinolin-1(2H)-yl)-1,3,5-triazine-2,4-
diyl)bis(N2,N2-dimethylethane-1,2-diamine) (53)
Yield: 63%; Semisolid; ESMS: 385 (M þ 1); IR (Neat) 3271, 3152,
2953, 1583, 1471, 1277, 1123, 758 cmꢂ1; 1H NMR (200 MHz, CDCl3):
d
(ppm) 7.82 (d, 1H, J ¼ 7.64 Hz), 7.14e6.97 (m, 3H), 6.09 (bs, 2H),
4.01 (t, 2H, J ¼ 5.81 Hz), 3.56e3.44 (m, 4H), 2.81e2.49 (m, 6H), 2.29
(s, 12H), 2.01 (m, 2H); 13C NMR (50 MHz, CDCl3): 165.01, 139.31,
132.25, 128.87, 126.19, 125.35, 124.21, 58.33, 44.61, 43.82, 36.45,
27.29, 24.16; Anal. Calcd for C20H32N8: C, 62.47; H, 8.39; N, 29.14;
Found: C, 62.43; H, 8.32; N, 29.06.
6.5.1. 6-(3,4-Dihydroquinolin-1(2H)-yl)-N2,N4-dipropyl-1,3,5-
triazine-2,4-diamine (48)
Yield: 68%; Semisolid; ESMS: 327 (M þ 1); IR (KBr) 3382, 3264,
2987, 1571, 1462, 1171, 756 cmꢂ1
;
1H NMR (200 MHz, CDCl3):
6.5.7. 6-(3,4-Dihydroquinolin-1(2H)-yl)-N2,N4-bis(2-
d
(ppm) 7.83 (m, 1H), 7.11e6.98 (m, 3H), 5.03 (bs, 2H), 4.01 (m, 2H),
morpholinoethyl)-1,3,5-triazine-2,4-diamine (54)
3.31 (m, 4H), 2.79 (t, 2H, J ¼ 6.27 Hz), 1.99e1.93 (m, 2H), 1.63e1.49
(m, 4H), 0.95 (t, 6H, J ¼ 7.24 Hz); 13C NMR (50 MHz, CDCl3): 165.17,
139.38, 131.19, 128.88, 126.42, 125.19, 123.53, 44.55, 42.97, 27.83,
24.22, 23.51, 11.91; Anal. Calcd for C18H26N6: C, 66.23; H, 8.03; N,
25.74; Found: C, 66.17; H, 8.01; N, 25.66.
Yield: 62%; Semisolid; ESMS: 469 (M þ 1); IR (Neat) 3330, 2945,
2859, 1547, 1437, 1340, 1118, 756 cmꢂ1; 1H NMR (200 MHz, CDCl3):
d
(ppm) 7.81 (m, 1H), 7.11e6.94 (m, 3H), 5.56 (bs, 2H), 4.01 (m, 2H),
3.71 (m, 8H), 3.49e2.41 (m, 4H), 2.79 (t, 2H, J ¼ 6.67 Hz), 2.56e2.47
(m, 12H), 1.99e1.93 (m, 2H); 13C NMR (50 MHz, CDCl3): 166.01,
165.25, 139.80, 131.29, 128.93, 126.37, 125.21, 123.60, 67.27, 58.01,
53.84, 44.52, 37.43, 27.76, 24.24; Anal. Calcd for C24H36N8O2: C,
61.52; H, 7.74; N, 23.91; Found: C, 61.51; H, 7.66; N, 23.82.
6.5.2. 6-(3,4-Dihydroquinolin-1(2H)-yl)-N2,N4-diisopropyl-1,3,5-
triazine-2,4-diamine (49)
Yield: 71%; Semisolid; ESMS: 327 (M þ 1); IR (Neat) 3276, 3143,
2928, 2852, 1573, 1436, 1325, 1316, 1224, 1110 cmꢂ1
;
1H NMR
6.5.8. 6-(3,4-Dihydroquinolin-1(2H)-yl)-N2,N4-diethyl-1,3,5-
triazine-2,4-diamine (55)
(200 MHz, CDCl3): d (ppm) 7.81 (m, 1H), 7.14e6.98 (m, 3H), 4.77 (bs,
2H), 4.14e4.02 (m, 2H), 3.99 (m, 2H), 2.78 (t, 2H, J ¼ 6.14 Hz),
1.99e1.92 (m, 2H), 1.19 (d, 12H, J ¼ 6.34 Hz); 13C NMR (50 MHz,
CDCl3): 166.11, 165.72, 139.47, 132.17, 129.20, 126.06, 125.90, 124.86,
43.28, 27.37, 26.87, 24.13; Anal. Calcd for C18H26N6: C, 66.23; H,
8.03; N, 25.74; Found: C, 66.21; H, 7.96; N, 25.63.
Yield: 62%; Semisolid; ESMS: 299 (M þ 1); IR (Neat) 3412, 3278,
2970, 1563, 1478, 1339, 1172, 756 cmꢂ1; 1H NMR (200 MHz, CDCl3):
d
(ppm) 7.86 (m, 1H), 7.15e6.93 (m, 3H), 4.99 (bs, 2H), 4.01 (m, 2H),
3.42e3.34 (m, 4H), 2.79 (t, 2H, J ¼ 6.51 Hz), 1.99e1.93 (m, 2H), 1.18
(t, 6H, J ¼ 7.28 Hz); 13C NMR (50 MHz, CDCl3): 165.25, 139.85,131.16,
128.90, 126.39, 125.22, 123.49, 44.51, 35.98, 27.83, 24.24, 15.52;
Anal. Calcd for C18H26N6: C, 64.40; H, 7.43; N, 28.16; Found: C,
64.36; H, 7.36; N, 28.04.
6.5.3. 6-(3,4-Dihydroquinolin-1(2H)-yl)-N2,N4-bis(3-
morpholinopropyl)-1,3,5-triazine-2,4-diamine (50)
Yield: 61%; Semisolid; ESMS: 497 (M þ 1); IR (Neat) 3328, 3162,
2967, 1586, 1432, 1357, 1218, 1122, 761 cmꢂ1
;
1H NMR (200 MHz,
6.5.9. N2,N4-Diethyl-6-(piperidin-1-yl)-1,3,5-triazine-2,4-diamine
(56)
CDCl3):
d (ppm) 7.82 (m, 1H), 7.10e6.97 (m, 3H), 5.75 (bs, 2H), 3.99
(m, 2H), 3.73 (m, 8H), 3.44 (m, 4H), 2.78 (t, 2H, J ¼ 6.58 Hz),
2.63e2.45 (m, 12H), 1.98e1.92 (m, 2H), 1.77e1.71 (m, 4H); 13C NMR
(50 MHz, CDCl3): 166.35, 165.18, 139.83, 131.18, 128.89, 126.43,
125.13, 123.52, 67.35, 57.54, 54.11, 44.46, 40.09, 27.80, 26.51, 24.20;
Yield: 64%; Semisolid; ESMS: 251 (M þ 1); IR (Neat) 3442, 3282,
2972, 2850, 1592, 1452, 1341, 1281, 1132 cmꢂ1; 1H NMR (200 MHz,
CDCl3):
d (ppm) 4.91 (bs, 2H), 3.71 (m, 4H), 3.41e3.31 (m, 4H), 1.58
(m, 6H), 1.16 (t, 6H, J ¼ 7.23 Hz); 13C NMR (50 MHz, CDCl3): 165.82,

3342
N. Sunduru et al. / European Journal of Medicinal Chemistry 45 (2010) 3335e3345
164.95, 44.47, 35.90, 26.23, 25.35,15.47; Anal. Calcd for C12H22N6: C,
57.57; H, 8.87; N, 33.57; Found: C, 57.52; H, 8.81; N, 33.48.
Calcd for C20H40N8: C, 61.19; H, 10.27; N, 28.54; Found: C, 61.11; H,
10.13; N, 28.51.
6.5.10. 6-(Piperidin-1-yl)-N2,N4-dipropyl-1,3,5-triazine-2,4-
diamine (57)
6.6. General procedure for the synthesis of compounds 64e86
Yield: 66%; mp 56e58 ꢁC; ESMS: 279 (M þ 1); IR (KBr) 3273, 2959,
To a mixture of intermediate 32 (1 equiv) and K2CO3 (1.5 equiv)
in dry THF, respective amines (1 equiv) were added and the reac-
tion mixture was stirred at room temperature for 2 h. After the
completion of reaction, isonicotinohydrazide (1.2 equiv) was added
to the above reaction mixture and refluxed for 8 h. When the
reaction is completed, solvent was evaporated to dryness under
vacuum. The solid residue obtained was purified with flash column
chromatography using chloroform to methanol gradient elution to
obtain the final compounds 64e68. The same procedure was
carried out to synthesize targeted compounds 69e73, 74e78 and
79e86 from the intermediates 33, 34 and 35 respectively.
2867, 1561, 1469, 1356, 1290, 1175 cmꢂ1; 1H NMR (200 MHz, CDCl3):
d
(ppm) 5.07 (bs, 2H), 3.86e3.72 (m, 4H), 3.32 (m, 4H),1.59e1.53 (m,
10H), 0.93 (d, 6H, J ¼ 7.06 Hz); 13C NMR (50 MHz, CDCl3): 165.99,
164.95, 44.48, 42.88, 26.22, 25.34, 23.44, 11.90; Anal. Calcd for
C14H26N6: C, 60.40;H, 9.41; N, 30.19;Found:C, 60.33;H, 9.37;N, 30.11.
6.5.11. N2,N4-Diisopropyl-6-(piperidin-1-yl)-1,3,5-triazine-2,4-
diamine (58)
Yield: 64%; mp 147e149 ꢁC; ESMS: 279 (M þ 1); IR (KBr) 3266,
2964, 2852, 1604, 1501, 1440, 1370, 1304, 1195 cmꢂ1 1H NMR
;
(200 MHz, CDCl3): d (ppm) 4.66 (bs, 2H), 4.17e4.07 (m, 2H), 3.69 (m,
4H),1.58 (m, 6H),1.17 (d,12H, J ¼ 6.47 Hz); 13C NMR (50 MHz, CDCl3):
165.74, 165.24, 44.42, 42.51, 26.24, 25.39, 23.42; Anal. Calcd for
C14H26N6:C, 60.40;H, 9.41;N, 30.19;Found:C, 60.35;H, 9.38;N, 30.17.
6.6.1. N0-(4-(Butylamino)-6-(3,4-dihydroquinolin-1(2H)-yl)-1,3,5-
triazin-2-yl)isonicotinohydrazide (64)
Yield: 68%; mp 162e164 ꢁC; ESMS: 419 (M þ 1); IR (KBr): 3412,
2978, 2925, 2846, 1647, 1553, 1495, 1438, 1251, 1105 cmꢂ1; 1H NMR
(200 MHz, CDCl3): d (ppm) 10.56 (bs, 1H), 8.69 (bs, 1H), 8.62 (d, 1H,
6.5.12. N2,N4-Di-tert-butyl-6-(piperidin-1-yl)-1,3,5-triazine-2,4-
diamine (59)
J ¼ 6.45 Hz), 7.81 (m, 2H), 7.05 (m, 2H), 6.72 (m, 1H), 6.56 (m, 1H),
6.88 (bs, 1H), 3.84 (s, 2H), 3.42 (m, 2H), 2.71e2.66 (m, 2H), 1.96 (m,
2H), 1.48 (m, 2H), 1.37 (m, 2H), 0.93 (t, 3H, J ¼ 7.12 Hz); 13C (50 MHz,
CDCl3,): 168.35,167.58,166.72,165.24,151.27,150.81,140.62,128.83,
126.55, 122.24, 120.74, 46.29, 44.35, 32.26, 26.33, 25.26, 20.47,
14.63; Anal. Calcd for C22H26N8O: C, 63.14; H, 6.26; N, 26.78; Found:
C, 63.06; H, 6.18; N, 26.73.
Yield: 63%; Semisolid; ESMS: 307 (M þ 1); IR (Neat) 3430, 2968,
2854, 1583, 1506, 1462, 1386, 1215, 1110 cmꢂ1 1H NMR (200 MHz,
;
CDCl3):
d (ppm) 5.17 (bs, 2H), 3.86 (m, 4H), 1.58 (m, 6H), 1.43 (s,
18H); 13C NMR (50 MHz, CDCl3): 166.70, 54.04, 51.31, 29.63, 29.35,
26.67, 24.02; Anal. Calcd for C16H30N6: C, 62.71; H, 9.87; N, 27.42;
Found: C, 62.66; H, 9.79; N, 27.38.
6.5.13. N2,N4-bis(2-Morpholinoethyl)-6-(piperidin-1-yl)-1,3,5-
triazine-2,4-diamine (60)
6.6.2. N0-(4-(tert-Butylamino)-6-(3,4-dihydroquinolin-1(2H)-yl)-
1,3,5-triazin-2-yl)isonicotinohydrazide (65)
Yield: 65%; Semisolid; ESMS: 421 (M þ 1); IR (Neat) 3420, 2935,
Yield: 71%; mp 196e198 ꢁC; ESMS: 419 (M þ 1); IR (KBr): 3425,
2857, 1582, 1469, 1358, 1281, 1116 cmꢂ1; 1H NMR (200 MHz, CDCl3):
3017, 2937, 2854, 1638, 1526, 1496, 1437, 1249, 1112 cmꢂ1; 1H NMR
d
(ppm) 5.56 (bs, 2H), 3.88 (m, 4H), 3.72 (m, 8H), 3.48 (m, 4H),
(200 MHz, CDCl3): d (ppm) 10.49 (bs, 1H), 8.77 (bs, 1H), 8.63 (d, 2H,
2.55e2.43 (m, 12H), 1.62 (m, 6H); 13C NMR (50 MHz, CDCl3): 167.46,
67.28, 57.76, 54.27, 53.76, 44.75, 26.22, 25.12; Anal. Calcd for C20H36
N8O2: C, 57.12; H, 8.63; N, 26.64; Found: C, 57.04; H, 8.49; N, 26.56.
J ¼ 7.92 Hz), 7.78 (m, 2H), 7.09 (m, 2H), 6.74 (m, 1H), 6.57 (m, 1H),
4.13 (bs, 1H), 3.88 (m, 2H), 2.72e2.69 (m, 2H), 1.96 (m, 2H), 1.29 (s,
9H); 13C (50 MHz, CDCl3): 168.56, 167.71, 166.49, 165.13, 151.22,
150.95, 140.38, 128.94, 126.58, 122.30, 120.76, 51.11, 44.64, 29.93,
27.66, 24.23; Anal. Calcd for C22H26N8O: C, 63.14; H, 6.26; N, 26.78;
Found: C, 63.17; H, 6.24; N, 26.69.
6.5.14. N2,N4-bis(3-Morpholinopropyl)-6-(piperidin-1-yl)-1,3,5-
triazine-2,4-diamine (61)
Yield: 61%; Semisolid; ESMS: 449 (M þ 1); IR (Neat) 3336, 3161,
2934, 2872, 1586, 1437, 1357, 1217, 1118 cmꢂ1
;
1H NMR (200 MHz,
6.6.3. N0-(4-(3,4-Dihydroquinolin-1(2H)-yl)-6-(isopropylamino)-
1,3,5-triazin-2-yl)isonicotinohydrazide (66)
CDCl3):
d (ppm) 5.71 (bs, 2H), 3.92 (m, 4H), 3.77 (m, 8H), 3.46 (m,
4H), 2.58e2.45 (m, 12H), 1.77e1.69 (m, 4H), 1.59 (m, 6H); 13C NMR
(50 MHz, CDCl3): 166.27, 165.21, 67.26, 57.61, 53.82, 53.26, 44.86,
30.09, 26.27, 25.13; Anal. Calcd for C22H40N8O2: C, 58.90; H, 8.99; N,
24.98; Found: C, 58.79; H, 8.92; N, 24.86.
Yield: 67%; mp 168e170 ꢁC; ESMS: 405 (M þ 1); IR (KBr): 3424,
3019, 2967, 2853, 1609, 1560, 1486, 1437, 1215, 1067 cmꢂ1; 1H NMR
(200 MHz, CDCl3): d (ppm) 10.46 (bs, 1H), 8.90 (bs, 1H), 8.76 (d, 2H,
J ¼ 4.76 Hz), 7.68 (m, 2H), 7.09e6.74 (m, 4H), 4.13 (bs, 1H), 3.88 (m,
3H), 2.73e2.68 (m, 2H), 1.81 (m, 2H), 1.12 (d, 6H, J ¼ 7.02 Hz); 13C
(50 MHz, CDCl3): 168.71, 166.57, 165.34, 164.75, 151.29, 150.73,
141.34, 128.82, 126.59, 121.61, 120.75, 51.14, 42.49, 27.53, 24.26,
23.57; Anal. Calcd for C21H24N8O: C, 62.36; H, 5.98; N, 27.70; Found:
C, 62.31; H, 5.95; N, 27.62.
1
1
2
2
0
6.5.15. N ,N -(6-(Piperidin-1-yl)-1,3,5-triazine-2,4-diyl)bis(N ,N -
dimethylethane-1,2-diamine) (62)
Yield: 64%; Semisolid; ESMS: 337 (M þ 1); IR (Neat) 3276, 2956,
2853,1583,1458,1328,1243,1128 cmꢂ1; 1H NMR (200 MHz, CDCl3):
d
(ppm) 5.98 (bs, 2H), 3.94 (m, 4H), 3.55 (m, 4H), 2.70e2.64 (m, 4H),
2.29 (s,12H),1.59 (m, 6H); 13C NMR (50 MHz, CDCl3): 165.18,164.76,
59.07, 54.17, 47.18, 45.83, 26.37, 25.26; Anal. Calcd for C16H32N8: C,
57.11; H, 9.59; N, 33.30; Found: C, 57.03; H, 9.52; N, 33.24.
6.6.4. N0-(4-(3,4-dihydroquinolin-1(2H)-yl)-6-morpholino-1,3,5-
triazin-2-yl)isonicotinohydrazide (67)
Yield: 69%; mp 183e185 ꢁC; ESMS: 433 (M þ 1); IR (KBr): 3398,
3012, 2925, 2854, 1608, 1525, 1496, 1437, 1272, 1094 cmꢂ1; 1H NMR
(200 MHz, CDCl3): d (ppm) 10.55 (bs, 1H), 9.00 (s, 1H), 8.76 (d, 2H,
1
1
2
2
0
6.5.16. N ,N -(6-(Piperidin-1-yl)-1,3,5-triazine-2,4-diyl)bis(N ,N -
diethylethane-1,2-diamine) (63)
J ¼ 3.58 Hz), 7.77 (m, 2H), 7.57 (d, 1H, J ¼ 8.32 Hz), 7.10 (m, 2H), 6.97
(m, 1H), 3.63e3.53 (m, 8H), 3.16 (m, 2H), 2.66 (m, 2H), 1.79 (m, 2H);
13C (50 MHz, CDCl3): 168.58, 167.42, 166.65, 165.28, 151.33, 150.81,
140.34, 128.86, 126.59, 122.43, 120.62, 67.51, 51.95, 44.63, 27.54,
24.29; Anal. Calcd for C22H24N8O2: C, 61.10; H, 5.59; N, 25.91;
Found: C, 61.13; H, 5.26; N, 25.44.
Yield: 62%; Semisolid; ESMS: 393 (M þ 1); IR (Neat) 3402, 2969,
2933, 2854, 1536, 1470, 1361, 1216, 1128 cmꢂ1; 1H NMR (200 MHz,
CDCl3): d (ppm) 5.94 (bs, 2H), 3.86 (m, 4H), 3.59 (m, 4H), 2.87e2.78
(m, 12H), 1.54 (s, 6H), 1.11 (t, 12H, J ¼ 6.98 Hz); 13C NMR (50 MHz,
CDCl3): 164.97, 54.30, 52.17, 47.58, 44.50, 26.21, 25.29, 11.36; Anal.

N. Sunduru et al. / European Journal of Medicinal Chemistry 45 (2010) 3335e3345
3343
6.6.5. N0-(4-(3,4-dihydroquinolin-1(2H)-yl)-6-(3-
morpholinopropylamino)-1,3,5-triazin-2-yl)isonicotinohydrazide
(68)
(m, 4H); 13C (50 MHz, CDCl3): 168.75, 166.13, 165.78, 153.35, 135.81,
135.44, 131.67, 129.32, 128.97, 124.85, 120.83, 48.67, 44.18, 31.84;
Anal. Calcd for C27H26N8O: C, 67.77; H, 5.48; N, 23.42; Found: C,
67.70; H, 5.36; N, 23.34.
Yield: 58%; mp 167e169 ꢁC; ESMS: 490 (M þ 1); IR (KBr): 3409,
2985, 2923, 2856, 1621, 1558, 1499, 1438, 1257, 1105 cmꢂ1; 1H NMR
(200 MHz, CDCl3):
d
(ppm) 10.48 (bs, 1H), 9.15 (s, 1H), 8.76 (m, 2H),
6.6.11. N0-(4-(Piperidin-1-yl)-6-(pyrimidin-2-ylamino)-1,3,5-
triazin-2-yl)isonicotinohydrazide (74)
7.77 (m, 2H), 7.58 (bs, 1H), 7.09e6.98 (m, 3H), 6.75 (m, 1H),
3.90e3.76 (m, 4H), 3.54 (m, 4H), 2.68 (m, 4H), 2.35 (m, 6H), 1.82 (m,
2H); 13C (50 MHz, CDCl3): 168.72, 167.46, 166.68, 165.13, 151.32,
150.91, 140.33, 128.86, 126.57, 122.38, 120.72, 67.39, 57.37, 53.45,
44.72, 41.31, 27.69, 24.33; Anal. Calcd for C25H31N9O2: C, 61.33; H,
6.38; N, 25.75; Found: C, 61.32; H, 6.10; N, 25.54.
Yield: 66%; mp 112e114 ꢁC; ESMS: 393 (M þ 1); IR (KBr): 3408,
3020, 2929, 2858, 1720, 1567, 1512, 1448, 1216, 1073 cmꢂ1; 1H NMR
(200 MHz, CDCl3):
d (ppm) 11.15 (bs, 1H), 8.74 (s, 1H), 8.19 (d, 2H,
J ¼ 4.56 Hz), 7.68 (m, 2H), 7.19 (d, 2H, J ¼ 5.28 Hz), 6.52 (m, 1H), 4.12
(bs,1H), 3.58e3.49 (m, 4H), 1.54e1.46 (m, 6H); 13C (50 MHz, CDCl3):
168.76, 167.81, 166.43, 165.49, 164.54, 158.87, 150.85, 132.53, 129.58,
110.92, 68.76, 29.24, 24.22; Anal. Calcd for C18H20N10O: C, 55.09; H,
5.14; N, 35.69; Found: C, 54.93; H, 5.04; N, 35.66.
6.6.6. N0-(4-(3,4-Dihydroisoquinolin-2(1H)-yl)-6-(piperidin-1-yl)-
1,3,5-triazin-2-yl)isonicotinohydrazide (69)
Yield: 67%; mp 87e89 ꢁC; ESMS: 431 (M þ 1); IR (KBr): 3359,
3016, 2925, 2857, 1681, 1525, 1445, 1254, 1112 cmꢂ1
;
1H NMR
6.6.12. N0-(4-(Butylamino)-6-(piperidin-1-yl)-1,3,5-triazin-2-yl)
isonicotinohydrazide (75)
(200 MHz, CDCl3):
d (ppm) 10.61 (bs, 1H), 8.93 (s, 1H), 8.83 (d, 2H,
J ¼ 3.80 Hz), 7.71 (d, 2H, J ¼ 3.80 Hz), 7.19e7.17 (m, 4H), 4.85 (s, 2H),
3.78e3.72 (m, 6H), 2.88 (m, 2H), 1.45e1.32 (m, 6H); 13C (CDCl3,
50 MHz): 168.94, 167.68, 166.35, 165.92, 153.17, 135.43, 135.27,
131.79, 129.56, 128.84, 124.76, 120.91, 48.66, 44.35, 44.16, 31.72,
25.49, 24.93; Anal. Calcd for C23H26N8O: C, 64.17; H, 6.09; N, 26.03;
Found: C, 64.08; H, 6.06; N, 26.04.
Yield: 72%; mp 143e145 ꢁC; ESMS: 371 (M þ 1); IR (KBr): 3386,
2971, 2913, 2856, 1638, 1531, 1498, 1448, 1252, 1068 cmꢂ1; 1H NMR
(200 MHz, CDCl3):
d (ppm) 10.07 (bs, 1H), 9.24 (s, 1H), 8.67 (d, 2H,
J ¼ 3.84 Hz), 7.71 (d, 2H, J ¼ 2.12 Hz), 6.86 (bs, 1H), 3.67 (m, 4H),
3.34e3.16 (m, 2H), 1.54e1.44 (m, 8H), 1.29 (m, 2H), 0.94 (t, 3H,
J ¼ 5.68 Hz); 13C (50 MHz, CDCl3): 168.24, 166.67, 165.35, 164.27,
151.19, 140.83, 122.35, 44.48, 32.36, 27.64, 24.16, 20.53, 14.62; Anal.
Calcd for C18H26N8O: C, 58.36; H, 7.07; N, 30.25; Found: C, 58.28; H,
7.12; N, 30.14.
6.6.7. N0-(4-(Butylamino)-6-(3,4-dihydroisoquinolin-2(1H)-yl)-
1,3,5-triazin-2-yl)isonicotinohydrazide (70)
Yield: 70%; mp 116e118 ꢁC; ESMS: 419 (M þ 1); IR (KBr): 3346,
3019, 2964, 1599, 1538, 1508, 1455, 1216, 1045 cmꢂ1
;
1H NMR
6.6.13. N0-(4-(tert-butylamino)-6-(piperidin-1-yl)-1,3,5-triazin-2-
yl)isonicotinohydrazide (76)
(200 MHz, CDCl3):
d (ppm) 10.48 (bs, 1H), 8.77 (m, 2H), 8.62 (bs,
1H), 7.68 (m, 2H), 7.14 (m, 4H), 6.92 (bs, 1H), 4.79 (s, 2H), 3.80e3.78
(m, 4H), 2.79e2.73 (m, 2H), 1.26e1.21 (m, 4H), 1.02 (t, 3H,
J ¼ 7.21 Hz); 13C (50 MHz, CDCl3): 168.86, 166.11, 165.95, 164.43,
151.28, 135.76, 135.04, 129.57, 127.19, 122.21, 78.17, 45.82, 42.37,
32.25, 28.86, 20.43, 14.62; Anal. Calcd for C22H26N8O: C, 63.14; H,
6.26; N, 26.78; Found: C, 63.07; H, 6.24; N, 26.70.
Yield: 68%; mp 110e112 ꢁC; ESMS: 371 (M þ 1); IR (KBr): 3412,
2961, 2924, 2856, 1654, 1527, 1495, 1437, 1242, 1093 cmꢂ1; 1H NMR
(200 MHz, CDCl3):
d (ppm) 10.46 (bs, 1H), 9.14 (bs, 1H), 8.74 (d, 2H,
J ¼ 4.48 Hz), 7.77 (m, 2H), 6.28 (bs, 1H), 3.64 (m, 4H), 1.56e1.42 (m,
6H), 1.21 (s, 9H); 13C (50 MHz, CDCl3): 167.84, 166.75, 165.51, 164.83,
151.27, 141.19, 122.25, 50.82, 44.36, 29.89, 26.24, 25.35; Anal. Calcd
for C18H26N8O: C, 58.36; H, 7.07; N, 30.25; Found: C, 58.32; H, 7.12;
N, 30.27.
6.6.8. N0-(4-(tert-Butylamino)-6-(3,4-dihydroisoquinolin-2(1H)-
yl)-1,3,5-triazin-2-yl)isonicotinohydrazide (71)
Yield: 68%; mp 125e127 ꢁC; ESMS: 419 (M þ 1); IR (KBr): 3347,
6.6.14. N0-(4-(Isopropylamino)-6-(piperidin-1-yl)-1,3,5-triazin-2-
yl)isonicotinohydrazide (77)
2967, 2929, 1591, 1542, 1501, 1452, 1231, 1106 cmꢂ1 1H NMR
;
(200 MHz, CDCl3):
d
(ppm) 10.46 (bs, 1H), 8.76 (m, 2H), 8.62 (bs,
Yield: 67%; mp 102e104 ꢁC; ESMS: 357 (M þ 1); IR (KBr): 3412,
1H), 7.78 (m, 2H), 7.14 (m, 4H), 6.35 (s, 1H), 4.67 (s, 2H), 3.90 (m,
2H), 2.81 (m, 2H), 1.22 (s, 9H); 13C (50 MHz, CDCl3): 168.95, 167.38,
165.24, 164.76, 153.15, 135.13, 131.71, 129.63, 129.68, 124.94, 120.75,
51.29, 48.71, 44.13, 31.81, 29.72; Anal. Calcd for C22H26N8O: C, 63.14;
H, 6.26; N, 26.78; Found: C, 63.02; H, 6.23; N, 26.80.
2965, 2917, 2845, 1610, 1527, 1499, 1447, 1274, 1114 cmꢂ1 1H NMR
;
(200 MHz, CDCl3):
d (ppm) 10.12 (bs, 1H), 9.34 (s, 1H), 8.65 (d, 2H,
J ¼ 4.64 Hz), 7.69 (m, 2H), 4.16 (bs, 1H), 4.02e3.97 (m, 1H), 3.67 (m,
4H), 1.52e1.47 (m, 6H), 1.15 (d, 6H, J ¼ 4.82 Hz); 13C (50 MHz,
CDCl3): 168.25, 166.63, 165.27, 164.83, 151.28, 140.85, 122.54, 51.47,
47.29, 26.34, 24.31, 23.18; Anal. Calcd for C17H24N8O: C, 57.29; H,
6.79; N, 31.44; Found: C, 57.31; H, 6.70; N, 31.36.
6.6.9. N0-(4-(3,4-Dihydroisoquinolin-2(1H)-yl)-6-
(isopropylamino)-1,3,5-triazin-2-yl)isonicotinohydrazide (72)
Yield: 63%; mp 99e101 ꢁC; ESMS: 405 (M þ 1); IR (KBr): 3406,
3025, 2962, 2854, 1647, 1565, 1496, 1448, 1253, 1114 cmꢂ1; 1H NMR
6.6.15. N0-(4,6-Di(piperidin-1-yl)-1,3,5-triazin-2-yl)
isonicotinohydrazide (78)
(200 MHz, CDCl3):
d
(ppm) 10.42 (bs, 1H), 8.77 (s, 2H), 8.65 (bs, 1H),
Yield: 71%; mp 153e155 ꢁC; ESMS: 383 (M þ 1); IR (KBr): 3387,
7.78 (m, 2H), 7.14 (m, 4H), 4.78 (s, 2H), 4.41 (m, 1H), 3.89e3.80 (m,
4H), 1.11 (d, 6H, J ¼ 4.84 Hz); 13C (50 MHz, CDCl3): 167.86, 166.14,
165.95, 164.47, 151.33, 135.72, 134.96, 129.68, 127.14, 122.32, 78.45,
45.71, 42.37, 28.83, 23.41; Anal. Calcd for C21H24N8O: C, 62.36; H,
5.98; N, 27.70; Found: C, 62.32; H, 5.91; N, 27.73.
3014, 2924, 2852, 1645, 1530, 1487, 1438, 1254, 1108 cmꢂ1; 1H NMR
(200 MHz, CDCl3):
d (ppm) 11.16 (bs, 1H), 10.46 (s, 1H), 8.74 (d, 2H,
J ¼ 3.72 Hz), 7.73 (d, 2H, J ¼ 4.34 Hz), 3.88 (m, 8H), 1.53e1.42 (m,
12H); 13C (50 MHz, CDCl3): 168.44, 165.86, 165.43, 151.21, 141.37,
122.25, 44.36, 26.21, 25.49; Anal. Calcd for C19H26N8O: C, 59.67; H,
6.85; N, 29.30; Found: C, 59.60; H, 6.81; N, 29.18.
6.6.10. N0-(4,6-bis(3,4-Dihydroisoquinolin-2(1H)-yl)-1,3,5-triazin-
2-yl)isonicotinohydrazide (73)
6.6.16. N0-(4-Morpholino-6-(phenylamino)-1,3,5-triazin-2-yl)
isonicotinohydrazide (79)
Yield: 67%; mp 161e163 ꢁC; ESMS: 479 (M þ 1); IR (KBr): 3407,
3024, 2925, 2851, 1683, 1524, 1490, 1448, 1240, 1101 cmꢂ1; 1H NMR
Yield: 66%; mp 180e182 ꢁC; ESMS: 393 (M þ 1); IR (KBr): 3414,
(200 MHz, CDCl3):
d (ppm) 10.52 (bs, 1H), 8.90 (s, 1H), 8.77 (m, 2H),
2926, 2923, 2854, 1648, 1561, 1502, 1436, 1272, 1113 cmꢂ1; 1H NMR
7.78 (d, 2H, J ¼ 4.86 Hz), 7.14 (m, 8H), 4.84 (s, 4H), 3.93 (m, 4H), 3.08
(200 MHz, CDCl3):
d (ppm) 10.65 (bs, 1H), 9.17 (s, 1H), 9.04 (s, 1H),

3344
N. Sunduru et al. / European Journal of Medicinal Chemistry 45 (2010) 3335e3345
8.78 (m, 2H), 7.83 (m, 2H), 7.63 (m, 2H), 7.23 (m, 1H), 6.93 (m, 2H),
3.68e3.64 (m, 8H); 13C (50 MHz, CDCl3): 168.92, 166.75, 164.83,
164.27, 151.61, 140.54, 138.96, 128.16, 122.34, 121.69, 119.82, 66.43,
43.47; Anal. Calcd for C19H20N8O2: C, 58.15; H, 5.14; N, 28.55;
Found: C, 58.02; H, 5.10; N, 28.39.
6.6.22. N0-(4-(tert-Butylamino)-6-(phenylamino)-1,3,5-triazin-2-
yl)isonicotinohydrazide (85)
Yield: 58%; mp 147e149 ꢁC; ESMS: 379 (M þ 1); IR (KBr): 3428,
3019, 2925, 1610, 1548, 1497, 1443, 1251, 1109 cmꢂ1 1H NMR
;
(200 MHz, CDCl3): d (ppm) 10.57 (bs, 1H), 8.93 (s, 1H), 8.77 (m, 3H),
7.82 (m, 4H), 7.21 (m, 1H), 6.89 (m, 2H), 6.49 (bs, 1H), 1.21 (s, 9H);
13C (50 MHz, CDCl3): 167.84, 166.36, 165.57, 164.71, 151.28, 141.24,
140.78, 128.93, 122.35, 122.15, 122.56, 51.22, 29.86; Anal. Calcd for
C19H22N8O: C, 60.30; H, 5.86; N, 29.61; Found: C, 60.16; H, 5.64; N,
29.65.
6.6.17. N0-(4-(Phenylamino)-6-(piperidin-1-yl)-1,3,5-triazin-2-yl)
isonicotinohydrazide (80)
Yield: 62%; mp 193e195 ꢁC; ESMS: 391 (M þ 1); IR (KBr): 3409,
2923, 2914, 2855, 1647, 1560, 1501, 1438, 1273, 1112 cmꢂ1; 1H NMR
(200 MHz, CDCl3):
d (ppm) 10.62 (bs, 1H), 9.08 (s, 1H), 8.95 (s, 1H),
8.78 (d, 2H, J ¼ 5.08 Hz), 7.82 (m, 2H), 7.63 (m, 2H), 7.25 (m, 1H),
6.91 (m, 2H), 3.71 (m, 4H), 1.59e1.49 (m, 6H); 13C (50 MHz, CDCl3):
168.47, 166.34, 165.26, 164.43,. 151.39, 141.22, 140.16, 128.97,
122.25, 122.23, 120.48, 44.54, 26.36, 25.29; Anal. Calcd for
C20H22N8O: C, 61.52; H, 5.68; N, 28.70; Found: C, 61.44; H, 5.58; N,
28.78.
6.6.23. N0-(4-(Isopropylamino)-6-(phenylamino)-1,3,5-triazin-2-
yl)isonicotinohydrazide (86)
Yield: 64%; mp 215e217 ꢁC; ESMS: 365 (M þ 1); IR (KBr): 3430,
3017, 2916, 1692, 1505, 1468, 1439, 1245, 1115 cmꢂ1 1H NMR
;
(200 MHz, CDCl3): d (ppm) 10.59 (bs, 1H), 9.08 (s, 1H), 8.90 (bs, 1H),
8.78 (d, 2H, J ¼ 3.04 Hz), 7.82e7.69 (m, 4H), 7.20 (m, 1H), 6.89 (m,
2H), 4.12 (m, 1H), 1.12 (d, 6H, J ¼ 4.17 Hz); 13C (50 MHz, CDCl3):
168.33, 166.78, 165.85, 165.13, 151.36, 141.34, 140.87, 128.94, 122.35,
122.18, 120.42, 42.34, 23.48; Anal. Calcd for C18H20N8O: C, 59.33; H,
5.53; N, 30.75; Found: C, 59.14; H, 5.49; N, 30.70.
6.6.18. N0-(4-(Cyclohexylamino)-6-(phenylamino)-1,3,5-triazin-2-
yl)isonicotinohydrazide (81)
Yield: 75%; mp 157e159 ꢁC; ESMS: 405 (M þ 1); IR (KBr): 3421,
2930, 2927, 1679, 1565, 1507, 1438, 1274, 1014 cmꢂ1 1H NMR
;
(200 MHz, CDCl3):
d (ppm) 10.60 (bs, 1H), 9.09 (s, 1H), 8.93e8.77
6.7. Procedure for the synthesis of compound 87
(m, 3H), 7.82e7.67 (m, 4H), 7.21 (m, 1H), 6.90 (m, 2H), 3.85 (bs,
1H), 2.52 (m, 1H), 1.84e1.48 (m, 6H), 1.22 (m, 4H); 13C (50 MHz,
CDCl3): 168.51, 166.38, 165.75, 165.13, 151.26, 141.34, 140.78,
128.94, 122.36, 122.15, 52.83, 33.56, 26.22, 25.96; Anal. Calcd for
C21H24N8O: C, 62.36; H, 5.98; N, 27.70; Found: C, 62.30; H, 5.86; N,
27.59.
To a mixture of intermediate 35 (1 equiv) and K2CO3 (2 equiv) in
dry THF, isonicotinohydrazide (2.1 equiv) was added and the
reaction mixture was refluxed at 80 ꢁC for 8 h. After the completion
of reaction, the solvent was evaporated to dryness and the solid
residue obtained was purified with flash column chromatography
using chloroform to methanol gradient elution to afford the
compound 87.
6.6.19. N0-(4-(3-Morpholinopropylamino)-6-(phenylamino)-1,3,5-
triazin-2-yl)isonicotinohydrazide (82)
Yield: 62%; mp 136e138 ꢁC; ESMS: 450 (M þ 1); IR (KBr): 3443,
6.7.1. N0,N00-(6-(Phenylamino)-1,3,5-triazine-2,4-diyl)
diisonicotinohydrazide (87)
2928, 3015, 2855, 1682, 1572, 1500, 1436, 1277, 1022 cmꢂ1; 1H NMR
Yield: 55%; mp 142e144 ꢁC; ESMS: 443 (M þ 1); IR (KBr): 3436,
(200 MHz, CDCl3): d (ppm) 10.62 (bs, 1H), 9.23 (s, 1H), 9.11 (bs, 1H),
2927, 3015, 1608, 1558, 1496, 1442, 1252, 1103 cmꢂ1 1H NMR
;
8.78 (m, 2H), 7.65 (d, 2H, J ¼ 3.94 Hz), 7.66 (m, 2H), 7.21 (m, 1H),
6.90 (m, 2H), 6.82 (bs, 1H), 3.59 (m, 6H), 2.36 (m, 6H), 1.73e1.70 (m,
2H); 13C (50 MHz, CDCl3): 167.84, 166.61, 165.35, 164.39, 151.25,
141.37, 140.72, 128.98, 122.34, 122.46, 122.13, 66.86, 56.62, 53.77,
38.34, 26.47; Anal. Calcd for C22H27N9O2: C, 58.78; H, 6.05; N, 28.04;
Found: C: 58.64; H: 6.12; N: 27.86.
(200 MHz, CDCl3): d (ppm) 10.58 (bs, 2H), 9.11 (s, 2H), 8.91e8.78 (m,
5H), 7.82e7.65 (m, 6H), 7.20 (m, 1H), 6.89 (m, 2H); 13C (50 MHz,
CDCl3): 168.52, 166.36, 165.74, 151.28, 141.93, 140.75, 128.96, 122.43,
122.16, 120.59; Anal. Calcd for C21H18N10O2: C, 57.01; H, 4.10; N,
31.66; Found: C, 57.14; H, 4.02; N, 31.53.
6.6.20. N0-(4,6-bis(Phenylamino)-1,3,5-triazin-2-yl)
isonicotinohydrazide (83)
Acknowledgements
Yield: 68%, mp 247e249 ꢁC; ESMS: 399 (M þ 1); IR (KBr): 3416,
N.S. thanks the Council of Scientific and Industrial Research
(India) for the award of Senior Research Fellowship and L.G. thanks
the University Grant Commission, New Delhi. N. S. also thanks
Nidhi Tibrewal. We are also thankful to S.A.I.F. Division, CDRI,
Lucknow for providing spectroscopic data. CDRI Communication
No. 7865.
3012, 2928, 1647, 1534, 1500, 1443, 1261, 1107 cmꢂ1 1H NMR
;
(200 MHz, CDCl3): d (ppm) 10.67 (bs, 1H), 9.26 (s, 1H), 9.19 (bs, 2H),
8.81 (d, 2H, J ¼ 5.76 Hz), 7.87 (d, 2H, J ¼ 1.54 Hz), 7.84e7.55 (m, 4H),
7.28 (m, 2H), 7.12e6.96 (m, 4H); 13C (50 MHz, CDCl3): 168.25,
165.43, 165.18, 164.74, 151.36, 140.81, 140.69, 129.53, 122.54, 122.19,
120.96; Anal. Calcd for C21H18N8O: C, 63.31; H, 4.55; N, 28.12;
Found: C, 63.45, H, 4.64; N, 28.04.
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6.6.21. N0-(4-(Butylamino)-6-(phenylamino)-1,3,5-triazin-2-yl)
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