A convenient method for the synthesis of 7-amino-substituted 1,2,4-triazolo[1,5-a][1,3,5]triazin-5-amines

Article abstract of DOI:10.1016/j.tetlet.2008.10.003

A new practical synthesis of 7-amino-substituted 1,2,4-triazolo[1,5-a][1,3,5]triazin-5-amines is developed. The triazine ring closure of 5-guanidino-3-phenyl-1,2,4-triazole with trichloroacetonitrile proceeds chemo- and regioselectively depending on the n

Full text of DOI:10.1016/j.tetlet.2008.10.003

Tetrahedron Letters 49 (2008) 7180–7183
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A convenient method for the synthesis of 7-amino-substituted
1,2,4-triazolo[1,5-a][1,3,5]triazin-5-amines q
*
Anton V. Dolzhenko , Giorgia Pastorin, Anna V. Dolzhenko, Wai Keung Chui
Department of Pharmacy, Faculty of Science, National University of Singapore, 18 Science Drive 4, Singapore 117543, Singapore
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 29 July 2008
Revised 19 September 2008
Accepted 1 October 2008
Available online 10 October 2008
A new practical synthesis of 7-amino-substituted 1,2,4-triazolo[1,5-a][1,3,5]triazin-5-amines is devel-
oped. The triazine ring closure of 5-guanidino-3-phenyl-1,2,4-triazole with trichloroacetonitrile proceeds
chemo- and regioselectively depending on the nature of the solvent. Conducting the reaction in toluene
provided 7-trichloromethyl-1,2,4-triazolo[1,5-a][1,3,5]triazin-5-amine as the product, which can be
further aminated efficiently with replacement of the trichloromethyl group.
Ó 2008 Elsevier Ltd. All rights reserved.
The 5-aza-analogues of purines, 1,2,4-triazolo[1,5-a][1,3,5]tri-
azines have attracted significant attention in recent years as
potential bioactive molecules. They are known to modulate the
processes that involve regulatory biogenic purines.2 Research in
this area has led to the development of 5,7-diamino-1,2,4-triazolo-
[1,5-a][1,3,5]triazines which demonstrate high affinity and selec-
tivity towards adenosine receptors, especially antagonistic activity
against A1 and A2A adenosine receptors.3 Among them, ZM 241385
(N5-[2-(4-hydroxyphenyl)ethyl]-2-(2-furyl)-1,2,4-triazolo[1,5-a]-
[1,3,5]triazine-5,7-diamine) has found application as a standard
reference compound and a useful tool for investigation of A2A
adenosine receptors.4 A number of ligands for various types of
adenosine receptors, which were developed using the purine
scaffold, have an alkyl, aralkyl or aryl substituted amino group
located at the carbon atom corresponding to position 7 of the
1,2,4-triazolo[1,5-a][1,3,5]triazine nucleus.5 However, these types
of 1,2,4-triazolo[1,5-a][1,3,5]triazines have not yet been explored
extensively.
Methods for the preparation of unsymmetrically substituted
5,7-diamino-1,2,4-triazolo[1,5-a][1,3,5]triazines typically involve
two general synthetic pathways. Both of the routes are similar
and utilize the same reagents, namely 5-amino-1,2,4-triazoles 1,
N-cyanocarbonimidates 2 and substituted amines 4, but react with
each other via different sequences as shown in Scheme 1.
The reaction of 5-amino-1,2,4-triazoles 1 with 2, using the
method initially developed by Caulkett et al.,6 provided a mixture
of products 5–7, the type and ratio of which depended on the reac-
tion conditions. The yields were usually poor and separation of the
products by chromatography was required. The compounds 5 and
6 were further converted into the desired 5,7-diamino-1,2,4-tri-
azolo[1,5-a][1,3,5]triazines 8 and 9 via reaction with amines 4.
An alternative synthesis of 5,7-diamino-1,2,4-triazolo[1,5-a]-
[1,3,5]triazines using the reaction of 5-amino-1,2,4-triazoles 1
with 3, initially prepared from N-cyanocarbonimidates 2 and
amines 4 required, as a rule, long reaction times, harsh conditions
and also provided mixtures of the compounds 8 and 9 separable by
chromatography.7
Due to the disadvantages of these methods, the practical and
regioselective synthesis of unsymmetrically substituted 5,7-
diamino-1,2,4-triazolo[1,5-a][1,3,5]triazines remains a challenging
problem. Therefore, a new simple synthetic approach to the prep-
aration of 7-amino-substituted 1,2,4-triazolo[1,5-a][1,3,5]triazin-
5-amines 9 would be a valuable contribution to the chemistry
and pharmacology of 1,2,4-triazolo[1,5-a][1,3,5]triazines.
Recently, we reported the synthesis of 1,2,4-triazolo[1,5-a]-
[1,3,5]triazines using a regioselective ring closing reaction of 5-
guanidino-1,2,4-triazoles.8 These synthons are readily available
which makes them attractive building blocks for the construction
of the 1,2,4-triazolo[1,5-a][1,3,5]triazine system. In this Letter,
we reveal some new aspects of their chemistry, and in particular,
we describe the reactions of 5-guanidino-1,2,4-triazole 13 with an-
other versatile reagent, trichloroacetonitrile.9
5-Guanidino-3-phenyl-1,2,4-triazole (13) was prepared via the
reaction of benzhydrazide (10) with cyanoguanidine (11) in the
presence of hydrochloric acid followed by treatment of the result-
ing N-benzamidobiguanide (12) with aqueous alkali (Scheme 2).8
The synthetic utility of trichloroacetonitrile in heterocyclic chemis-
try has been well recognized,9 particularly in ring closing reactions
as a one-carbon inserting reagent. We found that trichloroacetoni-
trile reacted with 5-guanidino-3-phenyl-1,2,4-triazole (13) afford-
ing different products in different solvents (Scheme 2). Treatment
of 13 with trichloroacetonitrile with heating in toluene proceeded
with elimination of ammonia and provided 5-amino-2-phenyl-7-
trichloromethyl-1,2,4-triazolo[1,5-a][1,3,5]triazine (14),10 exclu-
sively, in high yield. Analogous reaction in ethanol resulted in
q
Part 12 in the series ‘Fused heterocyclic systems with s-triazine ring’, for part 11
see Ref. 1.
* Corresponding author. Tel./fax: +65 6779 1554.
E-mail address: phada@nus.edu.sg (A. V. Dolzhenko).
0040-4039/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetlet.2008.10.003

A. V. Dolzhenko et al. / Tetrahedron Letters 49 (2008) 7180–7183
7181
XR2
N
NH2
N
R1
N
XR2
N
NH2
N
N
N
N
N
R2X
N
N
N
R1
R1
+
+
N
XR2
N
NH2
N
XR2
N
N
2
6
5
7
+
+
N NH
NHR3R4
4
NHR3R4
4
R1
NH2
N
1
NR3R4
N
NH2
N
NR3R4
7
N
N
N
N
N
N
R2X
N
N
R1
+
R1
2
N
NR3R4
N
NH2
5
XR2 = SMe, OPh
3
8
9
Scheme 1. General synthetic approach to unsymmetrically substituted 5,7-diamino-1,2,4-triazolo[1,5-a][1,3,5]triazines.
CCl3
N
N
N
Ph
N
N
R
N
NH2
14
iii
Ph
NH2
NH
NH
N NH
N
HN NH2
HN N
NH
HCl
N
N
i
ii
N
Ph
Ph
NH2
Ph
N
N
O
O NH2
NH2
H
iv
10
12
13
15
N
+
NH
NH2
N
N
N
H2N NH
v
N NH
H2N NH
N
Ph
+
Ph
NH2
N
NH
N
NH2
N
11
11
16
1a
Scheme 2. Reagents and conditions: (i) cyanoguanidine (1.1 equiv), HCl (1 equiv), EtOH, reflux, 4 h (80%); (ii) 10% NaOH, 80 °C, 6 h (68%); (iii) NCCCl3 (2.0 equiv), PhMe,
reflux, 7 h (94%); (iv) NCCCl3 (1.5 equiv), EtOH, reflux, 8 h (85%); (v) HCl (1.0 equiv), water, reflux, 12 h (64%).
the elimination of chloroform and formation of 5,7-diamino-2-
phenyl-1,2,4-triazolo[1,5-a][1,3,5]triazine (16), which was identi-
cal with the sample prepared via an alternative synthetic pathway
from 5-amino-1,2,4-triazole 1a and cyanoguanidine (11).11 Both
these reactions of 13 with trichloroacetonitrile were regioselective
and afforded only the products of ring closure at nitrogen atom N-1
of the triazole 13; the products of ring closure at N-4 (compound
15) were not isolated in any of the cases. This fact was confirmed
by 13C NMR data.10,11 In the [4,3-a] ring junction product, the signal
of the triazole ring carbon atom bearing the phenyl group would
appear at considerably higher field.6
The structure of product 14 was supported by NMR spectro-
scopy. The singlet due to the amino group protons at 8.24 ppm
together with the signals of the phenyl ring protons in the 1H
NMR spectrum and the signal of the trichloromethyl group at
89.2 ppm in the 13C NMR spectrum were diagnostic.
sequent elimination of chloroform from adduct 18 would afford
intermediate 19, which upon intramolecular cyclocondensation
would provide 16.
It was found that the trichloromethyl group of 14 readily under-
went nucleophilic substitution with amines affording 7-amino-
substituted 1,2,4-triazolo[1,5-a][1,3,5]triazin-5-amines 9 in good
yields (Table 1).12 This reaction was found to be general, and pro-
ceeded smoothly with a variety of primary and secondary amines
with alkyl, aryl and aralkyl substituents under heating at 100 °C
in dry DMF. The reaction of 14 with aliphatic amines (e.g., methyl-
amine and ethylamine) was also carried out conveniently with
excellent chemoselectivity affording 9 even in aqueous solutions
of excess amine.13
Both of the amino groups of compounds 9 were found to be lo-
cated in the plane of the 1,2,4-triazolo[1,5-a][1,3,5]triazine nucleus
and were strongly involved in
p electron delocalization with the
The role of ethanol in the synthesis of 5,7-diamino-1,2,4-triazol-
o[1,5-a][1,3,5]triazine (16) from 13 and trichloroacetonitrile can be
explained by initial formation of imidate 17 as illustrated in
Scheme 3. The addition of 17 to the guanidine group of 13 and sub-
heterocycle as were shown by NMR spectroscopy data and by an
X-ray crystallography study (Fig. 1).1 Rotation around the C-7–
NR1R2 bond was hindered leading to the broadening of the signals
of the NR1R2 group in the NMR spectra, particularly for compounds
NH2
CCl3
NH
EtO NH2
EtO
N
NH
13
N
N NH
N NH
16
EtOH
+
NH
NH
Cl3C OEt
- EtOH
Ph
Ph
N
- CHCl3
N
CCl3
N
N
H
H
17
18
19
Scheme 3. Proposed mechanism for the formation of 5,7-diamino-1,2,4-triazolo[1,5-a][1,3,5]triazine (16), and the role of ethanol.

7182
A. V. Dolzhenko et al. / Tetrahedron Letters 49 (2008) 7180–7183
Table 1
Synthesis of 7-amino-substituted 1,2,4-triazolo[1,5-a][1,3,5]triazin-5-amines (9)
CCl3
N
NR1R2
N
NHR1R2
- CHCl3
N
N
N
N
N
Ph
Ph
N
N
NH2
N
NH2
9
14
9
a
NHR1R2
Mp (°C)
Yield (%)
9
k
NHR1R2
Mp (°C)
Yield (%)
92
Cl
297–298a
95
251–253a
Me
H2N
NH2
N
Et
b
c
256–257a
283–284b
98
96
l
>300d
87
93
H2N
H2N
NH2
H2N
m
220–222b
OH
d
259–261c
92
n
291–292d
89
H2N
H2N
H2N
Me
Me
Me
N
e
f
207–208a
246–248b
270–272d
90
87
88
o
p
q
246–248b
276–277b
224–226a
90
94
90
N
H
Me
N
H
H2N
H2N
H2N
OMe
Cl
g
N
H
O
h
262–263b
86
r
230–232a
95
N
H
Me
N
i
j
215–216a
93
96
s
t
226a
92
88
N
H
NH2
OMe
187a
271–273b
N
H
NH2
a
b
c
d
Solvents: EtOH, MeOH, 70% aq EtOH, MeOCH2CH2OH.
with higher electron-donor properties of the NR1R2 fragment. This
also resulted in the magnetic inequivalence of the carbon atoms of
the pyrrolidino moiety of compound 9p in the 13C NMR spectrum.
In summary, we have found that the chemoselectivity of the
reaction of 5-guanidino-3-phenyl-1,2,4-triazole (13) with trichlo-
roacetonitrile depended on the nature of the solvent. Using toluene
as the solvent provided synthetically important 5-amino-2-phe-
nyl-7-trichloromethyl-1,2,4-triazolo[1,5-a][1,3,5]triazine (14). We
successfully developed a new method for the synthesis of previ-
ously difficult to access 7-amino-substituted 1,2,4-triazolo[1,5-a]-
[1,3,5]triazin-5-amines via reaction of 14 with various amines. In
general, this synthetic approach is practical and utilizes easily
available starting materials, simple procedures and provides inter-
esting derivatives of the 5-azapurine system in excellent yields and
purity.
Figure 1. X-ray crystal structure of 9o.1

A. V. Dolzhenko et al. / Tetrahedron Letters 49 (2008) 7180–7183
7183
11. Dolzhenko, A. V.; Dolzhenko, A. V.; Chui, W. K. Heterocycles 2007, 71, 429–
436.
Acknowledgements
12. General method for the preparation of 7-amino-substituted 1,2,4-triazolo[1,5-a]-
[1,3,5]triazin-5-amines (9c–t): Compound 14 (0.66 g, 2.0 mmol) was added to a
solution of the appropriate amine (2.5 mmol) in DMF (5 ml) and the mixture
was heated at 70–80 °C with stirring for 2–5 h. After cooling, ice-cold water
(40 ml) was added and the product was filtered and recrystallized from a
suitable solvent (Table 1).
This work is supported by the National Medical Research Coun-
cil, Singapore (NMRC/NIG/0020/2008) and the National University
of Singapore (R-148-050-091-101/133 and R-148-000-069-112).
The authors thank Koh Lip Lin, Tan Geok Kheng and Woo Su Fen
for the X-ray crystallography study.
Experimental data for some representative compounds:
Compound 9c: 1H NMR (300 MHz, DMSO-d6): d 1.46–1.65 (m, 2H), 1.64–1.84
(m, 4H), 1.88–2.06 (m, 2H), 4.42 (sep, J = 7.3 Hz, 1H), 7.01 (s, 2H, NH2), 7.44–
7.58 (m, 3H), 8.07–8.21 (m, 2H), 8.32 (t, J = 7.9 Hz, 1H, NH); 13C NMR (75 MHz,
DMSO-d6): d 23.4 (2CH2), 31.5 (2CH2), 51.9 (CH), 126.6 (2CH), 128.5 (2CH),
129.9 (CH), 130.8, 148.5, 159.3, 162.4, 162.6. Anal. Calcd for C15H17N7: C, 61.00;
H, 5.80; N, 33.20. Found: C, 60.91; H, 5.98; N, 33.07.
References and notes
1. Dolzhenko, A. V.; Tan, G. K.; Koh, L. L.; Woo, S. F.; Chui, W. K. Acta Crystallogr.
2008, E64, o2021.
Compound 9f: 1H NMR (300 MHz, DMSO-d6): d 7.21 (t, J = 7.5 Hz, 1H), 7.23 (s,
2H, NH2), 7.42 (t, J = 7.9 Hz, 2H), 7.47–7.60 (m, 3H), 7.89 (d, J = 8.3 Hz, 2H),
8.16–8.27 (m, 2H), 10.23 (s, 1H, NH); 13C NMR (75 MHz, DMSO-d6): d 122.8
(2CH), 124.6 (CH), 126.8 (2CH), 128.5 (2CH), 128.6 (2CH), 130.1 (CH), 130.7,
137.0, 147.2, 159.4, 162.0, 162.8. Anal. Calcd for C16H13N7: C, 63.36; H, 4.32; N,
32.32. Found: C, 63.13; H, 4.45; N, 32.08.
2. For
a review on 1,2,4-triazolo[1,5-a][1,3,5]triazines see: Dolzhenko, A. V.;
Dolzhenko, A. V.; Chui, W. K. Heterocycles 2006, 68, 1723–1759.
3. De Zwart, M.; Vollinga, R. C.; Beukers, M. W.; Sleegers, D. F.; Von Frijtag Drabbe
Kunzel, J. K.; De Groote, M.; Ijzerman, A. P. Drug Dev. Res. 1999, 48, 95–103;
Peng, H.; Kumaravel, G.; Yao, G.; Sha, L. I.; Wang, J.; Van Vlijmen, H.; Bohnert,
T.; Huang, C.; Vu, C. B.; Ensinger, C. L.; Chang, H.; Engber, T. M.; Whalley, E. T.;
Petter, R. C. J. Med. Chem. 2004, 47, 6218–6229; Vu, C. B.; Shields, P.; Peng, B. O.;
Kumaravel, G.; Jin, X.; Phadke, D.; Wang, J.; Engber, T.; Ayyub, E.; Petter, R. C.
Bioorg. Med. Chem. Lett. 2004, 14, 4835–4838; Vu, C. B.; Pan, D.; Peng, B. O.; Sha,
L. I.; Kumaravel, G.; Jin, X.; Phadke, D.; Engber, T.; Huang, C.; Reilly, J.; Tam, S.;
Petter, R. C. Bioorg. Med. Chem. Lett. 2004, 14, 4831–4834; Vu, C. B.; Peng, B. O.;
Kumaravel, G.; Smits, G.; Jin, X.; Phadke, D.; Engber, T.; Huang, C.; Reilly, J.;
Tam, S.; Grant, D.; Hetu, G.; Chen, L.; Zhang, J.; Petter, R. C. J. Med. Chem. 2004,
47, 4291–4299; Vu, C. B.; Pan, D.; Peng, B. O.; Kumaravel, G.; Smits, G.; Jin, X.;
Phadke, D.; Engber, T.; Huang, C.; Reilly, J.; Tam, S.; Grant, D.; Hetu, G.; Petter, R.
C. J. Med. Chem. 2005, 48, 2009–2018.
Compound 9i: 1H NMR (300 MHz, DMSO-d6): d 4.68 (d, J = 4.1 Hz, 2H), 7.07 (s,
2H, NH2), 7.26 (t, J = 7.2 Hz, 1H), 7.35 (t, J = 7.3 Hz, 2H), 7.42 (d, J = 7.2 Hz, 2H),
7.45–7.57 (m, 3H), 8.09–8.19 (m, 2H), 9.03 (t, J = 4.1 Hz, 1H, NH). 13C NMR
(75 MHz, DMSO-d6): d 43.1 (CH2), 126.6 (2CH), 127.0 (CH), 127.4 (2CH), 128.2
(2CH), 128.6 (2CH), 130.0 (CH), 130.8, 138.4, 149.1, 159.4, 162.4, 162.8. Anal.
Calcd for C17H15N7: C, 64.34; H, 4.76; N, 30.90. Found: C, 64.17; H, 5.06; N,
30.69.
Compound 9o: 1H NMR (300 MHz, DMSO-d6): d 3.50 (br s, 6H), 6.96 (s, 2H,
NH2), 7.43–7.56 (m, 3H), 8.03–8.14 (m, 2H). 13C NMR (75 MHz, DMSO-d6): d
39.3 (NMe2), 126.5 (2CH), 128.6 (2CH), 130.0 (CH), 130.6, 149.8, 161.3, 161.6,
161.6. Anal. Calcd for C12H13N7: C, 56.46; H, 5.13; N, 38.41. Found: C, 56.22; H,
5.24; N, 38.09.
4. Alexander, S. P. H.; Mathie, A.; Peters, J. A. Guide to Receptors and Channels, 3rd
ed., 2008. Br. J. Pharmacol. 2008, 153, S11–S12.
Compound 9t: 1H NMR (300 MHz, DMSO-d6): d 3.37 (t, J = 8.5 Hz, 2H), 4.99 (t,
J = 8.5 Hz, 2H), 7.09 (t, J = 7.3 Hz, 1H), 7.24 (t, J = 7.3 Hz, 1H), 7.26 (s, 2H, NH2),
7.32 (d, J = 7.5 Hz, 1H), 7.45–7.57 (m, 3H), 8.08–8.19 (m, 2H), 8.49 (d, J = 7.9 Hz,
1H); 13C NMR (75 MHz, DMSO-d6): d 27.9 (CH2), 51.8 (CH2), 118.6 (CH), 124.0
(CH), 124.7 (CH), 126.5 (2CH), 126.7 (CH), 128.5 (2CH), 130.0 (CH), 130.6,
132.7, 142.1, 147.1, 161.1, 161.5, 161.9. Anal. Calcd for C18H15N7: C, 65.64; H,
4.59; N, 29.77. Found: C, 65.69; H, 4.64; N, 29.69.
5. For some recent reviews on adenosine receptor ligands see: Jacobson, K. A.;
Gao, Z.-G. Nat. Rev. Drug Discovery 2006, 5, 247–264; Moro, S.; Gao, Z.-G.;
Jacobson, K. A.; Spalluto, G. Med. Res. Rev. 2006, 26, 131–159; Cristalli, G.;
Cacciari, B.; Dal Ben, D.; Lambertucci, C.; Moro, S.; Spalluto, G.; Volpini, R.
ChemMedChem 2007, 2, 260–281; Baraldi, P. G.; Tabrizi, M. A.; Gessi, S.; Borea,
P. A. Chem. Rev. 2008, 108, 238–263.
6. Caulkett, P. W. R.; Jones, G.; McPartlin, M.; Renshaw, N. D.; Stewart, S. K.;
Wright, B. J. Chem. Soc., Perkin Trans. 1 1995, 801–808.
7. Berecz, G.; Pongo, L.; Kovesdi, I.; Reiter, J. J. Heterocycl. Chem. 2002, 39, 327–334.
8. Dolzhenko, A. V.; Chui, W. K.; Dolzhenko, A. V.; Chan, L. W. J. Fluorine Chem.
2005, 126, 759–763; Dolzhenko, A. V.; Dolzhenko, A. V.; Chui, W. K. Tetrahedron
2007, 63, 12888–12895.
13. General method for the preparation of 7-amino-substituted 1,2,4-triazolo[1,5-a]-
[1,3,5]triazin-5-amines (9a,b): Compound 14 (0.66 g, 2.0 mmol) was added to a
cold solution (0–5 °C) of the appropriate amine (5 ml of 40% aq MeNH2 or 70%
aq EtNH2) and the mixture was stirred in an ice-bath for 20 min and then for
another 40 min at room temperature. Cold water (20 ml) was added and the
product was filtered and recrystallized from EtOH.
9. For reviews on trichloroacetonitrile see: Shvekhgeimer, G. A. Chem. Heterocycl.
Compd. 1993, 29, 1241–1264; Sherif, S. M.; Erian, A. W. Heterocycles 1996, 43,
1083–1118.
Compound 9a: 1H NMR (300 MHz, DMSO-d6): d 2.97 (s, 3H), 7.05 (s, 2H, NH2),
7.45–7.57 (m, 3H), 8.05–8.17 (m, 2H), 8.39 (s, 1H, NH); 13C NMR (75 MHz,
DMSO-d6): d 27.1 (NMe), 126.5 (2CH), 128.6 (2CH), 129.9 (CH), 130.8, 149.3,
159.2, 162.4, 162.6. Anal. Calcd for C11H11N7: C, 54.76; H, 4.60; N, 40.64. Found:
C, 54.52; H, 4.75; N, 40.36.
10. 2-Phenyl-7-trichloromethyl-1,2,4-triazolo[1,5-a][1,3,5]triazin-5-amine (14):
Guanidine 13 (4.04 g, 20 mmol) and trichloroacetonitrile (2.0 ml, 40 mmol)
were heated in toluene (50 ml) with stirring for 7 h. After cooling, the product
formed was filtered and washed with toluene (10 ml) and cold ethanol (10 ml).
Yield 6.20 g, 94%, mp 262–263 °C. 1H NMR (300 MHz, DMSO-d6): d 7.48–7.66
(m, 3H), 8.09–8.22 (m, 2H), 8.24 (s, 2H, NH2); 13C NMR (75 MHz, DMSO-d6): d
89.2, 127.1 (2CH), 128.8 (2CH), 129.7, 130.9 (CH), 150.2, 160.3, 160.7, 164.4.
Anal. Calcd for C11H7Cl3N6: C, 40.09; H, 2.14; N, 25.50. Found: C, 39.85; H, 2.23;
N, 25.36.
Compound 9b: 1H NMR (300 MHz, DMSO-d6): d 2.97 (t, J = 7.2 Hz, 3H), 3.50
(quintet, J = 6.7 Hz, 2H), 7.03 (s, 2H, NH2), 7.45–7.57 (m, 3H), 8.08–8.18 (m,
2H), 8.47 (t, J = 5.7 Hz, 1H, NH); 13C NMR (75 MHz, DMSO-d6): d 14.4 (Me), 35.0
(CH2), 126.6 (2CH), 128.6 (2CH), 129.9 (CH), 130.8, 148.7, 159.3, 162.4, 162.6.
Anal. Calcd for C12H13N7: C, 56.46; H, 5.13; N, 38.41. Found: C, 56.28; H, 5.34;
N, 38.25.