Regioselective synthesis and bioactivity of new 5-amino-6- Arylamino-pyrazolo[3,4-d]-pyrimidin-4(5H)-one derivatives

Article abstract of DOI:10.1002/jhet.26

A novel approach to regioselective synthesis of new 5-amino-6-arylamino-1H- pyrazolo[3,4-d]pyrimi- din-4(5H)-one 5 derivatives via a tandem aza-wittig and annulation reaction of iminophosphorance 2, aromatic isocyanates and hydrazine in 69.6-94.7% isolated yields is reported. The compound 5 reacted with triethyl orthoformate to give compound 6 in good yield (65.8-82.8%). Their structure was clearly confirmed by spectroscopy data (IR, ¹H NMR, MS, elemental analysis) and the results of preliminary bioassay indicated that compounds 5 and 6 possess high antifungal activity against Botrytis cinerea Pers and Sclerotinia sclerotiorum, and compound 5h showed 100, 96.4, and 90.2% inhibitory rate to Botrytis cinerea Pers, Pyricularia oryzae, and Sclerotinia sclerotiorum at the concentration of 50 mg/L. The antifungal activities of compound 6 were generally higher than those of compound 5.

Full text of DOI:10.1002/jhet.26

256
Regioselective Synthesis and Bioactivity of New 5-Amino-6-
arylamino-pyrazolo[3,4-d]-pyrimidin-4(5H)-one Derivatives
Vol 46
Hong-Qing Wang,a* Wei-Ping Zhou,b Yu-Yuan Wang,a Can-Rong Lin,a and
Zhao-Jie Liuc
aCollege of Chemistry and Chemical Engineering, University of South China, Hunan 421001,
People’s Republic of China
bCollege of Mathematics and Physical, University of South China, Hunan 421001,
People’s Republic of China
cThe Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of
Chemistry, Central China Normal University, Wuhan 430079, People’s Republic of China
*E-mail: hqwang2001cn@yahoo.com.cn
Received February 26, 2008
DOI 10.1002/jhet.26
Published online 13 April 2009 in Wiley InterScience (www.interscience.wiley.com).
A novel approach to regioselective synthesis of new 5-amino-6-arylamino-1H-pyrazolo[3,4-d]pyrimi-
din-4(5H)-one 5 derivatives via a tandem aza-wittig and annulation reaction of iminophosphorance 2,
aromatic isocyanates and hydrazine in 69.6–94.7% isolated yields is reported. The compound 5 reacted
with triethyl orthoformate to give compound 6 in good yield (65.8–82.8%). Their structure was clearly
confirmed by spectroscopy data (IR, 1H NMR, MS, elemental analysis) and the results of preliminary
bioassay indicated that compounds 5 and 6 possess high antifungal activity against Botrytis cinerea
Pers and Sclerotinia sclerotiorum, and compound 5h showed 100, 96.4, and 90.2% inhibitory rate to
Botrytis cinerea Pers, Pyricularia oryzae, and Sclerotinia sclerotiorum at the concentration of 50 mg/L.
The antifungal activities of compound 6 were generally higher than those of compound 5.
J. Heterocyclic Chem., 46, 256 (2009).
INTRODUCTION
compounds of potential biochemical interest. However, we
obtained 5-amino-6-arylamino-1H-pyrazolo[3,4-d]pyrimi-
Pyrazolopyrimidines and related fused heterocycles
have been the focus of great interest over many years
due to the fact that many compounds containing a fused
pyrimidinone ring have remarkable biological and che-
motherapeutic properties [1]. Pyrazolo[3,4-d]-pyrimi-
dines are often employed as mGluR1 antagonists [2],
antimicrobial and antifungal or antitumor agents [3],
various animal enzyme inhibitors [4], and agrochemicals
[5]. Moreover, triazole and its fused heterocycles form
part of an extensive investigation of biologically active
compounds, such as substituted triazole derivatives [6],
triazolo[1,5-a]pyrimidine derivatives [7], and their deriv-
atives [8]. In our previous research [5a–d], we reported
a reaction of ethyl 3-alkylthio-1-phenyl-5-triphenylphos-
din-4(5H)-ones
5 instead of 6-hydrazino-5-aryl-pyra-
zolo[3,4-d]pyrimidin-4-one 7 derivatives. Here, we report
a novel facile regioselective synthesis of a new series of
5-amino-6-arylamino-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-
ones 5, having nitrogen atoms from hydrazine, and 2H-
pyrazolo[3,4-d][1,2,4]triazolo[1,5-a] pyrimidin-4-one
derivatives 6 and their results of preliminary bioassay
against Botrytis cinerea Pers, Pyricularia oryzae, Gib-
berella zeae, and Sclerotinia sclerotiorum.
RESULTS AND DISCUSSION
Iminophosphoranes 2 [5a–c] reacted with isocyanates
to give the key intermediates carbodiimide 3. Treatment
of 3 with hydrazines at room temperature gave the inter-
mediate guanidines 4 [5a], which, in the presence of
NaOEt, reacted to give the crude target compound 5.
After evaporation of part of the solvent, the crude prod-
ucts were collected by filtration. After recrystallization
from DMF/petroleum ether or column chromatography
on a silica gel, white crystals were obtained in 69.6–
94.7% yields (Scheme 1, Table 1). The spectra data
phoranoimino-1H-pyrazole-4-carboxylate
(abbreviation
iminophosphorane) 2 with isocycanates and alkylamine to
give 6-alkylamino-5-aryl-pyrazolo[3,4-d]pyrimidin-4-one
derivatives, the nitrogen atom of which were from isocyca-
nates. Those compounds showed satisfactory antifungicidal
activities. Inspired by the manifold biological activities of
pyrazolo[3,4-d]pyrimidines and pyrazolotriazolopyrimidine
derivatives, we set out to utilize hydrazine to produce new
C
V
2009 HeteroCorporation

March 2009
Regioselective Synthesis and Bioactivity of New 5-Amino-6-arylamino-pyrazolo-
[3,4-d]-pyrimidin-4(5H)-one Derivatives
257
Scheme 1
identified the white crystal as 3-alkylthio-5-amino-6-ary-
lamino-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-ones
5 instead of the isomer 3-alkylthio-6-hydrazine-5-aryl-1-
phenyl-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-ones 7. In this
reaction, a variety of substituents can be tolerated in Ar
group, such as electron-donating group (e.g., Me), or
electron-withdrawing group (e.g., F, Cl). R1 also could
be C6H5 or H. In the absence of sodium ethoxide, the
compound 5 would be obtained with very low yields if
the quantity of hydrazine was equal to iminophosphor-
anes 2. In contrast, in the presence of a large excess of
hydrazine the reaction took place smoothly and the com-
pound 5 was obtained in satisfactory yields even in the
absence of NaOEt. On refluxing Compound 5 with
triethyl orthoformate, compound 6 was obtained in
65.8–82.8% yields in the present p-TsOH.
The structures of compounds 5 and 6 were deduced
from their spectra data (1H NMR, IR, EI-MS, and ele-
mentary analysis). 1H NMR spectra of compound 5
showed the signal of NH2 at d 5.55–5.74 as singlet and
compound 6 showed the signal of triazole at d 9.23–
9.34 as singlet [8b]. A combination of chemical shift
and couplings allowed the complete and unambiguous
assignment of all signals and demonstrated that the
major products correspond to structure. The IR spectra
of 5 exhibited NAH, C¼¼O, and C¼¼N absorptions. The
EI-MS spectra of 5 and 6 showed the molecular ion
peak. All the fragmentation ions were consistent with
their structures and could be clearly assigned. In addi-
tion, the structures of compound 6 further verified the
proposed structure of compound 5. The results of the el-
ementary analysis are within the acceptable range.
Table 1
Yields of compounds 5 and 6.
Compounds
R
R1
Ar
Yield of 5 (%)
Yield of 6 (%)
5a, 6a
5b, 6b
5c, 6c
5d, 6d
5e, 6e
5f, 6f
5g, 6g
5h
Me
Me
Me
Me
H
H
H
C6H5
75.8
84.6
69.6
92.5
72.3
94.7
73.8
77.0
83.0
86.2
74.2
71.6
73.2
82.8
77.6
69.0
65.8
76.3
p-MeC6H4
o-ClC6H4
o-FC6H4
C6H5
p-MeC6H4
o-ClC6H4
p-ClC6H4
p-MeC6H4
m-ClC6H4
p-MeC6H4
H
PhCH2
PhCH2
PhCH2
Me
H
H
H
H
5i
5j
5k
Me
Me
C6H5
C6H5
C6H5
PhCH2
Isolated yields based on iminophosphoranes 2.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

258
H.-Q. Wang, W.-P. Zhou, Y.-Y. Wang, C.-R. Lin, and Z.-J. Liu
Vol 46
Table 2
Antifungal activity of compounds 5, 6, and thiabendazole (50 mg/L, inhibitory rate %).
Relative inhibition (%)
Compounds
Botrytis
Pyricularia
Gibberella
Sclerotinia
5a/6a
5b/6b
5c/6c
5d/6d
5e/6e
5f/6f
5g/6g
5h
13.2/98.6
94.7/82.2
73.3/62.9
93.0/60.0
60.5/73.3
89.5/91.8
42.2/77.8
100.0
35.7/80.0
57.1/28.6
0.0/50.0
62.5/5.2
50.0/28.6
85.7/14.3
0.0/28.6
96.4
14.3/65.8
40.0/51.4
40.0/23.7
51.2/25.7
28.6/60.0
37.1/48.6
37.1/68.7
85.7
80.2/100.0
86.5/96.4
82.1/81.0
97.1/50.0
83.5/92.9
78.5/89.3
60.7/92.9
90.2
5i
5j
5k
26.3
7.9
21.0
100
21.4
50.0
28.6
87
22.9
5.7
5.7
100
81.9
79.3
76.2
100
Thiabendazole
phenyl-1H-pyrazole-4-carboxylate 1 [10], iminophosphoranes 2
[5a–c] were prepared according to literature.
General procedure for the preparation of 3-alkylthio-5-
amino-6-arylamino-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-
Biological activities. The fungi were obtained from
the College of Plant Protect, Central China Agriculture
University, China. The antifungal activities of all com-
pounds 5, 6, and 2-(40-thiazoly)-benzimidazole (com-
mercial name: thiabendazole), a commercially available
fungicide, were evaluated in vitro according to the
reported method [9], as shown in Table 2 by contrasting
to distilled water. The results showed that all com-
pounds 5 and 6 possessed good inhibition effects against
Sclerotinia sclerotiorum (inhibition rates 60.7–97.1%
and 81.0–100%). Comparing compounds 5 with 6, it
showed that the antifungal activities of compound 6
were generally higher than those of compound 5. Some
of the compounds 5 and 6 exhibited good inhibitory
rates against Botrytis cinerea Pers and Pyricularia ory-
zae. For example, the inhibitory rates of compounds 6a,
5b, 6b, 5d, 5f, and 6f were 91.8, 94.7, 82.2, 93.0, 89.5,
and 91.8% to Botrytis cinerea Pers and that of 5f was
85.7% to Pyricularia oryzae at 50 mg/L. It was also
interesting to note that compound 5h showed high anti-
fungal activities to all of Botrytis cinerea Pers, Pyricu-
laria oryzae, Gibberella zeae, and Sclerotinia
sclerotiorum.
4(5H)-ones (5). To
a solution of iminophosphorane 2
(2 mmol) in dry methylene dichloride (20 mL) aryl isocyanate
(2 mmol) was added under nitrogen atmosphere at room tem-
perature. After the reaction mixture was stirred for 1.5 h,
0.118 g (2.0 mmol, 85%) of hydrazine hydrate or 0.227 g (2.0
mmol) phenylhydrazine was added, and the resulting mixture
was stirred for an additional 30 min. Then the solvent was
removed under reduced pressure, and 25 mL anhydrous etha-
nol and 1.5 mL of sodium ethoxide (3 mol/L) in ethanol were
added to the mixture. After 3 h of stirring at room tempera-
ture, the solution was concentrated under reduced pressure and
successively cooled. The crude product was collected by filtra-
tion. After recrystallization from DMF/petroleum ether or col-
umn chromatography on silica gel, white crystal was obtained.
5-Amino-3-methylthio-1-phenyl-6-phenylamino-1H-pyra-
zolo[3,4-d]pyrimidin-4(5H)-one (5a). White crystals, mp
236.2–238.1ꢁC; IR (KBr) m (cmꢀ1): 3336, 3267, 1692, 1596,
1554, 909, 770, 743, 688; 1H NMR (DMSO-d6, 400 MHz) d
2.60 (s, 3H, SCH3), 5.57 (br s, 2H, NH2), 7.11 (t, 1H, J ¼ 7.2
Hz, Ph), 7.25 (t, 1H, J ¼ 7.2 Hz, Ph), 7.36 (t, 2H, J ¼ 7.6 Hz,
Ph), 7.46 (d, 2H, J ¼ 7.6 Hz, Ph), 7.73 (d, 2H, J ¼ 7.5 Hz,
Ph), 8.03 (d, 2H, J ¼ 7.8 Hz, Ph), 9.67 (s, 1H, NHPh); EI-MS
(70 eV, m/z, rel. int.) 365 (M þ 1, 49), 364 (Mþ, 81); Anal.
Calcd. for C18H16N6OS: C, 59.32; H, 4.43; N, 23.06; Found:
C, 59.1; H, 4.37; N, 22.96.
5-Amino-3-methylthio-1-phenyl-6-tolylamino-1H-pyrazolo[3,4-
d]pyrimidin-4(5H)-one (5b). White crystals, mp 235.3–238.6ꢁC;
IR (KBr) m (cmꢀ1): 3333, 3261, 1691, 1597, 1555, 751, 690;
1H NMR (DMSO-d6, 400 MHz) d 2.30 (s, 3H, p-CH3C6H4),
2.60 (s, 3H, SCH3), 5.55 (s, 2H, NH2), 6.85–7.68 (m, 7H, Ar),
8.03 (d, 2H, J ¼ 7.5 Hz, Ar), 9.57 (s, 1H, NH); EI-MS (70
eV, m/z, rel. int.) 379 (M þ 1, 31), 378 (Mþ,100); Anal.
Calcd. for C19H18N6OS: C, 60.30; H, 4.79; N, 22.21; Found:
C, 59.99; H, 4.61; N, 22.45.
EXPERIMENTAL
Melting points were determined using a WRS-1B Digital
melting point apparatus. MS was measured on a Finnigan
Trace Mass 2000 Spectrometer at 70 eV. IR was recorded on
an Avatar 360 Spectrometer as KBr pellets with absorption
given in cmꢀ1. H NMR spectra were obtained using a Varian
1
Mercury 400 (or 300) Spectrometer with TMS as the internal
reference and DMSO-d6 or CDCl3 as the solvent. Elementary
analysis was taken on a Vario EL III elementary analysis
instrument. All of the solvents and materials were of reagent
grade and purified as required. Ethyl 5-amino-3-alkylthio-1-
5-Amino-3-methylthio-1-phenyl-6-(o-chlorophenylamino)-
1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one (5c). White crystals,
mp 248.1–248.8ꢁC; IR (KBr) m (cmꢀ1): 3328, 3189, 1688,
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

March 2009
Regioselective Synthesis and Bioactivity of New 5-Amino-6-arylamino-pyrazolo-
[3,4-d]-pyrimidin-4(5H)-one Derivatives
259
1
1598, 1582, 1562, 1543, 1398, 752, 682; H NMR (DMSO-d6,
400 MHz): d 2.61 (s, 3H, SCH3), 5.74 (s, 2H, NH2), 7.20 (t,
1H, J ¼ 7.6 Hz, Ar), 7.30 (t, 1H, J ¼ 7.6 Hz, Ar), 7.43–7.50
(m, 3H, Ar), 7.58 (d, 1H, J ¼ 8.0 Hz, Ar), 8.00 (d, 2H, J ¼
7.6 Hz, Ar), 8.30 (d, 1H, J ¼ 8.0 Hz, Ar), 9.85 (br s, 1H,
NH); EI-MS (70 eV, m/z, rel. int.) 399 (M þ 1, 41), 398 (Mþ,
66); Anal. Calcd. for C18H15ClN6OS: C, 54.20; H, 3.79; N,
21.07; Found: C, 54.32; H, 3.76; N, 21.22.
222.4–222.8ꢁC; IR (KBr) m (cmꢀ1): 3369, 3252, 1690, 1598,
1546, 949, 761, 689; 1H NMR (CDCl3, 400 MHz) d 2.34 (s,
3H, C6H4CH3), 2.58 (s, 3H, SCH3), 6.86 (d, 2H, J ¼ 7.5 Hz,
Ar), 6.91 (t, 1H, J ¼ 7.2 Hz, Ar), 7.06 (br s, 1H, PhNHN),
7.13 (d, 2H, J ¼ 8.1 Hz, Ar), 7.24–7.27 (m, 3H, Ar), 7.41 (t,
2H, J ¼ 8.0 Hz, Ar), 7.50 (d, 2H, J ¼ 8.1 Hz, Ar), 8.06 (d,
2H, J ¼ 8.1 Hz, Ar), 8.35 (s, 1H, NH); EI-MS (70 eV, m/z,
rel. int.) 455 (M þ 1, 46), 454 (Mþ, 81); Anal. Calcd. for
C25H22N6OS: C, 66.06; H, 4.88; N, 18.49; Found: C, 65.80;
H, 4.85; N, 18.57.
5-Amino-3-methylthio-1-phenyl-6-(o-fluorophenylamino)-
1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one (5d). White crystal,
mp 238–239ꢁC; IR (KBr) m (cmꢀ1): 3352, 3314, 3266, 1721,
1621, 1600, 1542 (Ar), 1455, 922, 768; 1H NMR (DMSO-d6,
400 MHz) d 2.61(s, 3H, SCH3), 5.65 (s, 2H, NH2), 7.25–7.46
(m, 6H, Ar), 7.98 (d, 3H, J ¼ 8.4 Hz, Ar), 9.61(s, 1H, o-
FC6H4NH); EI-MS (70 eV, m/z, rel. int.): 384 (M þ 2, 13),
3-Methylthio-1-phenyl-5-phenylamino-6-(m-chlorophenyla-
mino)-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one
(5j). White
crystals, mp 208.5–210.5ꢁC; IR (KBr) m (cmꢀ1): 3342, 3261,
1695, 1599, 1545, 951, 759, 683; H NMR (CDCl3, 300 MHz)
1
d 2.54 (s, 3H, SCH3), 6.84 (d, 2H, J ¼ 7.5 Hz, Ar), 7.01 (t,
2H, J ¼ 7.2 Hz), 7.08–7.29 (m, 5H, Ar and PhNHN), 7.45 (t,
2H, J ¼ 7.8 Hz, Ar), 8.01 (d, 2H, J ¼ 7.8 Hz, Ar), 8.14 (s,
1H, m-ClC6H4), 8.51 (s, 1H, ArNH); EI-MS (70 eV, m/z, rel.
int.) 475 (M þ 1, 35), 474 (Mþ, 69); Anal. Calcd. for
C24H19ClN6OS: C, 60.69; H, 4.03; N, 17.69; Found: C, 60.39;
H, 4.00; N, 17.72.
3-Benzylthio-1-phenyl-5-phenylamino-6-(p-tolylamino)-1H-
pyrazolo[3,4-d]pyrimidin-4(5H)-one (5k). White crystals, mp
198.6–198.8ꢁC; IR (KBr) m (cmꢀ1): 3317, 3271, 1701, 1592,
1547, 772, 688; 1H NMR (CDCl3, 400 MHz) d 2.34 (s, 3H,
C6H4CH3), 4.42 (s, 2H, PhCH2), 6.86 (d, 2H, J ¼ 7.5 Hz, Ar),
7.01 (t, 2H, J ¼ 6.9 Hz, Ar), 7.12–7.28 (m, 8H, Ar and
PhNHN), 7.39–7.43 (m, 4H, Ar), 7.48 (t, 2H, J ¼ 6.4 Hz, Ar),
8.07 (d, 2H, J ¼ 7.8 Hz, Ar), 8.33 (s, 1H, NH); EI-MS (70
eV, m/z, rel. int.) 531 (M þ 1, 26), 530 (Mþ, 50); Anal. Calcd.
for C31H26N6OS: C, 70.17; H, 4.94; N, 15.84; Found: C,
69.89; H, 5.00; N, 15.63.
383 (M
þ
1, 49), 382 (Mþ, 89); Anal. Calcd. for
C18H15FN6OS: C, 56.53; H, 3.95; N, 21.98; Found: C, 56.39;
H, 3.92; N, 22.03.
5-Amino-3-benzylthio-1-phenyl-6-phenylamino-1H-pyra-
zolo[3,4-d]pyrimidin-4(5H)-one (5e). White crystals, mp
226.0–227.8ꢁC, IR (KBr) m (cmꢀ1): 3319, 1684, 1596, 1554,
1
927, 759, 689,501; H NMR (CDCl3, 300 MHz) d 4.47 (s, 2H,
CH2Ph), 5.58 (s, 2H, NH2), 7.12 (t, 1H, J ¼ 7.2 Hz, Ph),
7.20–7.50 (m, 10H, Ph), 7.73 (d, 2H, J ¼ 8.1 Hz), 8.04 (d,
2H, J ¼ 8.4 Hz), 9.69 (s, 1H, PhNH); EI-MS (70 eV, m/z, rel.
int.): 442 (M þ 2, 2), 441 (Mþ, 7); Anal. Calcd. for
C24H20N6OS: C, 65.44; H, 4.58; N, 19.08; Found: C, 65.52;
H, 4.43; N, 19.07.
5-Amino-3-benzylthio-1-phenyl-6-(p-tolylamino)-1H-pyra-
zolo[3,4-d]pyrimidin-4(5H)-one (5f). White crystals, mp
250.0–250.6ꢁC; IR (KBr) m (cmꢀ1): 3314, 3255, 1689, 1596,
1
1556, 770, 692; H NMR (DMSO-d6, 400 MHz) d 2.29 (s, 3H,
CH3), 4.46 (s, 2H, PhCH2), 5.56 (s, 2H, NH2), 6.83–6.91 (m,
1H, Ar), 7.16 (d, 2H, J ¼ 7.5 Hz, Ar) 7.14–7.49 (m, 7H, Ar),
7.59 (d, 2H, J ¼ 7.8 Hz, Ar), 8.04 (d, 2H, J ¼ 8.1 Hz, Ar),
9.54 (br s, 1H, NH); EI-MS (70 eV, m/z, rel. int.) 454 (Mþ,
26); Anal. Calcd. for C25H22N6OS: C, 66.06; H, 4.88; N,
18.49; Found: C, 66.25; H, 4.89; N, 18.36.
General Procedure for the preparation of 3-alkylthio-8-
aryl-phenyl-1,8-dihydropyrazolo[3,4-d][1,2,4]triazolo[1,5-a]
pyrimidin-4-one (6). To a suspension of the appropriate 5-
amino-3-alkylthio-6-arylamino-1-phenyl-1H-
pyrazolo[3,4-
d]pyrimidin-4(5H)-one 5 (1.5 mmol) in 25 mL of triethyl
orthoformate p-toluenesulfonic acid (p-TsOH) (0.4 g, 2.25
mmol) was added. The reaction mixture was refluxed for 15 h
under stirring. After cooling to room temperature, a yellowish
substance precipitated. The crude product was collected by fil-
tration and washed with water. After recrystallization from
dimethylformamide, the products were obtained as colorless
crystal.
5-Amino-3-benzylthio-1-phenyl-6-(o-chlorophenylamino)-
1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one (5g). White crystals,
mp 219.6–220.3ꢁC; IR (KBr) m (cmꢀ1): 3333, 3257, 3192,
1
1677, 1598, 1585, 1545, 1215, 754, 687; H NMR (DMSO-d6,
400 MHz) d 4.48 (s, 2H, PhCH2), 5.74 (br s, 2H, NH2), 7.22–
7.52 (m, 10H, Ar), 7.59 (d, 1H, J ¼ 7.6 Hz, Ar), 7.99 (d, 2H,
J ¼ 7.6 Hz, Ar), 8.30 (d, 1H, J ¼ 8.0 Hz, Ar), 9.83 (br s, 1H,
NH); EI-MS (70 eV, m/z, rel. int.) 474 (Mþ, 13); Anal. Calcd.
for C24H19ClN6OS: C, 60.69; H, 4.03; N, 17.69; Found: C,
60.58; H, 4.09; N, 17.82.
3-Methylthio-1,8-diphenyl-1,8-2H-pyrazolo[3,4-d][1,2,4]tria-
zolo[1,5-a]pyrimidin-4-one (6a). White crystals, mp 253–
255ꢁC, IR (KBr) m (cmꢀ1): 3144, 3081, 2925, 1718, 1605,
1578, 1560, 1527, 1388, 1265, 1165, 902, 768; 1H NMR
(DMSO-d6, 400 MHz) d 2.65 (s, 3H, SCH3), 7.31 (t, 1H, J ¼
6.8 Hz, Ph), 7.49–7.57 (m, 3H, Ph), 7.67 (t, 2H, J ¼ 8.2 Hz,
Ph), 7.93 (d, 2H, J ¼ 8.0 Hz, Ph), 8.08 (d, 2H, J ¼ 8.4 Hz,
Ph), 9.34 (s, 1H, triazole-H); EI-MS (70 eV, m/z, rel. int.) 375
(M þ 1, 13), 374 (Mþ, 36); Anal. Calcd. for C19H14N6OS: C,
60.95; H, 3.77; N, 22.45; Found: C, 61.02; H, 3.75; N, 22.53.
3-Methylthio-1-phenyl-8-(p-methylphenyl)-1,8-2H-pyrazolo[3,
4-d][1,2,4]triazolo[1,5-a]pyrimidin-4-one (6b). White crystals,
mp 253–256ꢁC, IR(KBr) m (cmꢀ1): 3133, 3076, 2919, 1721,
5-Amino-3-methylthio-1-phenyl-6-(p-chlorophenylamino)-
1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one (5h). White crystals,
mp 245.2–247.5ꢁC; IR (KBr) m (cmꢀ1): 3380, 3311, 3125,
1718, 1601, 1562, 1543, 925, 768; 1H NMR (DMSO-d6, 400
MHz) d 2.60 (s, 3H, SCH3), 5.57 (s, 2H, NH2), 7.28 (t, 1H, J
¼ 7.2 Hz, Ar), 7.40 (d, 2H, J ¼ 8.7 Hz, Ar), 7.49 (t, 2H, J ¼
7.9 Hz, Ar), 7.78 (d, 2H, J ¼ 8.7 Hz, Ar), 8.00 (d, 2H, J ¼
7.8 Hz, Ar), 9.81 (s, 1H, NH); EI-MS (70 eV, m/z, rel. int.)
399 (M
þ
1, 41), 398 (Mþ, 78); Anal. Calcd. for
1
C18H15ClN6OS: C, 54.20; H, 3.79; N, 21.07; Found: C, 54.07;
H, 3.71; N, 21.30.
1596, 1574, 1398, 1169, 900, 767, 673; H NMR (DMSO-d6,
400 MHz) d 2.41 (s, 3H, p-CH3Ph), 2.67 (s, 3H, SCH3), 7.31
(t, 1H, J ¼ 7.6 Hz, Ar), 7.45–7.53 (m, 4H, Ar), 7.80 (d, 2H, J
¼ 8.0 Hz, Ar), 8.07 (d, 2H, J ¼ 8.0 Hz, Ar), 9.29 (s, 1H,
3-Methylthio-1-phenyl-5-phenylamino-6-(p-tolylamino)-1H-
pyrazolo[3,4-d]pyrimidin-4(5H)-one (5i). White crystals, mp
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

260
H.-Q. Wang, W.-P. Zhou, Y.-Y. Wang, C.-R. Lin, and Z.-J. Liu
Vol 46
REFERENCES AND NOTES
triazole-H); EI-MS (70 eV, m/z, rel. int.) 389 (M þ 1, 22),
388 (Mþ, 62); Anal. Calcd. for C20H16N6OS: C, 61.84; H,
4.15; N, 21.63; Found: C, 61.90; H, 4.13; N, 21.65.
[1] (a) Vicentini, C. B.; Romagnoli, C.; Andreotti, E.; Mares, D. J
Agric Food Chem 2007, 55, 10331; (b) Cushman, M.; Sambaiah, T.; Jin, G.;
Illarionov, B.; Fischer, M.; Backer, A. J Org Chem 2004, 69, 601; (c) Dec-
pecker, G.; Patino, N.; Giorgio, C. D.; Terreux, R.; Cabrol-Bass, D.; Bailly,
C.; Aubertin, A.-M.; Condom, R. Org Biomol Chem 2004, 2, 74; (d) Haragu-
chi, K.; Kubota, Y.; Tanaka, H. J Org Chem 2004, 69, 1831; (e) Hoepping,
A.; Scheunemann, M.; Fischer, S.; Deuther-Conrad, W.; Hiller, A.; Wegner,
F.; Diekers, M.; Steinbach, J.; Brust, P. Nucl Med Biol 2007, 34, 559.
[2] Wang, X.-Q.; Kolasa, T.; El Kouhen, O. F.; Chovan, L. E.;
Black-Shaefer, C. L.; Wagenaar, F. L.; Garton, J. A.; Moreland, R. B.;
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3-Methylthio-1-phenyl-8-(o-chlorophenyl)-1,8-dihydropyra-
zolo[3,4-d][1,2,4]triazolo[1,5-a]pyrimidin-4-one (6c). White
crystals, mp 216–218ꢁC, IR (KBr) m (cmꢀ1): 3139, 3069,
1
1722, 1609, 1585, 1525, 1398, 1229, 1124, 902, 766, 687; H
NMR (DMSO-d6, 400 MHz) d 2.64 (s, 3H, SCH3), 7.27 (t,
1H, J ¼ 7.6 Hz, Ar), 7.44 (t, 2H, J ¼ 7.8 Hz, Ar), 7.66–7.70
(m, 2H, Ar), 7.83–7.90 (m, 2H, Ar), 7.94 (d, 2H, J ¼ 8.0 Hz,
Ph), 9.23 (s, 1H, triazole-H); EI-MS (70 eV, m/z, rel. int.): 409
(M þ 1, 32), 408 (Mþ, 57); Anal. Calcd. for C19H13ClN6OS:
C, 55.81; H, 3.20; N, 20.55; Found: C, 55.85; H, 3.22; N,
20.51.
3-Methylthio-1-phenyl-8-(o-fluorophenyl)-1,8-dihydropyra-
zolo[3,4-d][1,2,4]triazolo[1,5-a]pyrimidin-4-one (6d). White
crystal, mp 224–225ꢁC; IR (KBr) m (cmꢀ1): 3146, 1712, 1607,
1585, 1525, 1509, 1398, 1234, 904, 769, 752; 1H NMR
(DMSO-d6, 400 MHz) d 2.65 (s, 3H, SCH3), 7.29 (t, 1H, J ¼
7.4 Hz, Ar), 7.44–7.69 (m, 5H, Ar), 7.92 (t, 1H, J ¼ 7.6 Hz,
Ar), 8.00 (d, 2H, J ¼ 8.0 Hz, Ar), 9.23 (s, 1H, triazole-H); EI-
MS (70 eV, m/z, rel. int.): 393 (M þ 1, 31), 392 (Mþ, 63);
Anal. Calcd. for C19H13FN6OS: C, 58.15; H, 3.34; N, 21.42;
Found: C, 58.13; H, 3.32; N, 21.48.
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R.; Wang, J. Y.; Hubbard, R.; Kawai, M.; Erickson, S.; Bamaung, N.;
Fidanze, S. World Patent 2007079164, 2007; Chem. Abstr 2007, 147,
166335; (b) Tian, G. H.; Lai, S.; Wang, Z.; Zhu, Y.; Chen, X. J.; Ji,
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146, 21822; (c) Guzi, T. J.; Paruch, K.; Dwyer, M. P. US Patent
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J.; Dewdney, N. J.; Gabriel, T. World Patent 2007023111, 2007;
Chem Abstr 2007, 146, 295928; (e) Burchat, A. F.; Calderwood, D. J.;
Friedman, M. M.; Hirst, G. C.; Li, B.-H.; Rafferty, P.; Ritter, K.; Skin-
ner, B. S. Bioorg Med Chem Lett 2002, 12, 1687.
3-Benzylthio-1,8-diphenyl-1,8-dihydropyrazolo[3,4-d][1,2,4]
triazolo[1,5-a]pyrimidin-4-one (6e). White crystals, mp 224–
226ꢁC; IR (KBr) m (cmꢀ1): 3118, 3064, 1718, 1608, 1580,
1
1528, 1389, 1163, 757, 685; H NMR (DMSO-d6, 400 MHz) d
4.51 (s, 2H, PhCH2), 7.26 (t, 1H, J ¼ 7.2 Hz, Ph), 7.34 (t, 3H,
J ¼ 7.4 Hz, Ph), 7.50–7.67 (m, 7H, Ph), 7.92 (d, 2H, J ¼ 7.6
Hz, Ph), 8.08 (d, 2H, J ¼ 7.6 Hz, Ph), 9.34 (s, 1H, triazole-
H); EI-MS (70 eV, m/z, rel. int.) 450 (Mþ, 8); Anal. Calcd. for
C25H18N6OS: C, 66.65; H, 4.03; N, 18.65; Found: C, 66.70;
H, 4.02; N, 18.70.
3-Benzylthio-8-(p-tolyl)-1-phenyl-1,8-dihydropyrazolo[3,4-d]
[1,2,4]triazolo[1,5-a]pyrimidin-4-one (6f). White crystals, mp
257–259ꢁC; IR (KBr) m (cmꢀ1): 3137, 2923, 1718, 1601,
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(a) Wang, H.-Q.; Ding, M.-W.; Liu, Z.-J. Heteroatom Chem
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1
1580, 1527, 1390, 1165, 978, 769, 702; H NMR (DMSO-d6,
400 MHz) d 2.41 (s, 3H, p-CH3Ph), 4.52 (s, 2H, PhCH2),
7.32–7.53 (m, 10H, Ar), 7.79 (d, 2H, J ¼ 8.0 Hz, Ar), 8.08 (d,
2H, J ¼ 8.0 Hz, Ar), 9.29 (s, 1H, triazole-H); EI-MS (70 eV,
m/z, rel. int.): 464 (Mþ, 6); Anal. Calcd. for C26H20N6OS: C,
67.22; H, 4.34; N, 18.09; Found: C, 67.26; H, 4.37; N, 18.12.
3-Benzylthio-8-(o-chlorophenyl)-1-phenyl-1,8-dihydropyra-
zolo[3,4-d][1,2,4]triazolo[1,5-a]pyrimidin-4-one (6g). White
crystals, mp 221–223ꢁC; IR (KBr) m (cmꢀ1): 3144, 1718,
[6] Zhang, S.-S.; Wan, J.; Li, C.-L.; Li, X.-M.; Qu, B. J Heter-
ocycl Chem 2007, 44, 75.
1
1704, 1605, 1561, 1399, 1122, 1065, 905, 770, 687; H NMR
(DMSO-d6, 400 MHz) d 4.52 (s, 2H, PhCH2), 7.26–7.89 (m,
12H, Ar), 7.94 (d, 2H, J ¼ 8.4 Hz, Ar), 9.23 (s, 1H, triazole-
H); EI-MS (70 eV, m/z, rel. int.): 393 (M þ 1, 9), 392 (Mþ,
6); Anal. Calcd. for C15H17ClN6OS: C, 61.92; H, 3.53; N,
17.33; Found: C, 62.00; H, 3.58; N, 17.32.
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Acknowledgments. This work was supported by the Hunan Pro-
vincial Natural Science Foundation of China (No. 05JJ30022)
and Scientific Research Fund of the Hunan Provincial Education
Department (No. 06B081).
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Journal of Heterocyclic Chemistry
DOI 10.1002/jhet