Synthesis, reactions, and antimicrobial activity of some novel pyrazolo[3,4-d]pyrimidine, pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine, and pyrazolo[4,3-e][1,2,4]triazolo[3,4-c]pyrimidine derivatives

Article abstract of DOI:10.1002/jhet.3835

Treatment of N-phenyl-substituted benzenecarbo-hydrazonoyl chlorides 1a-d with malononitrile in sodium ethoxide solution gave 5-amino-4-cyanopyrazole derivatives 2-5. Compounds 2-5 were converted to formidate derivatives 6-9 upon treatment with TEOF in ac

Full text of DOI:10.1002/jhet.3835

Received: 6 October 2019
DOI: 10.1002/jhet.3835
Revised: 5 November 2019
Accepted: 11 November 2019
A R T I C L E
Synthesis, reactions, and antimicrobial activity of some
novel pyrazolo[3,4-d]pyrimidine, pyrazolo[4,3-e][1,2,4]
triazolo[1,5-c]pyrimidine, and pyrazolo[4,3-e][1,2,4]triazolo
[3,4-c]pyrimidine derivatives
Hamdi M. Hassaneen1
| Fatma M. Saleh1 | Tayseer A. Abdallah1
|
Yasmin Sh. Mohamed2 | Enas M. Awad3
1Department of Chemistry, Faculty of
Abstract
Science, Cairo University, Giza, Egypt
2National Organization for Drug Control
and Research, Dokki, Giza, Egypt
3Chemistry of Natural and Microbial
Products Department, Pharmaceutical and
Drug Industries Research Division,
National Research Centre, Cairo, Egypt
Treatment of N-phenyl-substituted benzenecarbo-hydrazonoyl chlorides 1a-
with malononitrile in sodium ethoxide solution gave 5-amino-
d
4-cyanopyrazole derivatives 2-5. Compounds 2-5 were converted to formidate
derivatives 6-9 upon treatment with TEOF in acetic anhydride. The reaction
of the latter products 6-9 with hydrazine hydrate gave imino-amino deriva-
tives 10-13, which was converted to hydrazino derivatives 14-17 by refluxing
with hydrazine hydrate. Hydrazino as well as imino-amino derivatives
undergo condensation, cyclization, and cycloaddition reactions to give
pyrazolo[3,4-d]pyrimidine 18-21, pyrazolo[4,3-e][1,2,4]triazolo-[3,4-c]pyrimi-
dine 22-27, and pyrazolo[30,40:4,5]pyrimido[1,6-b][1,2,4]triazine 42-44 deriva-
tives. Antimicrobial studies are performed using two Gram-positive bacteria
and two Gram-negative bacteria. Data indicated that compounds 5, 28D,
29B, and 31D are exploring elevated antibacterial effects against all strains
tested. Compound 28D is the most promising antibacterial agent against the
delicate bacterial strain Bacillus subtilis and Pseudomonas aeruginosa with
high effectiveness (low minimum inhibitory concentration [MIC] value)
40 and 60 μg/mL, respectively.
Correspondence
Hamdi M. Hassaneen, Department of
Chemistry, Faculty of Science, Cairo
University, Giza 12613, Egypt.
Email: hamdi_251@yahoo.com
1 | INTRODUCTION
cyclizing agents. Furthermore, attempts to prepare the
isomeric pyrazol[4,3-e][1,2,4]triazolo[4,3-c] pyrimidines
A survey of literature reveals that pyrazolo[3,4-d]pyrimi-
dine derivatives have attracted considerable interest
because of their biological activity as purine analogs.[1–3]
In addition, compounds containing 1,2,4-triazolo[1,5-c]
pyrimidine moiety were reported to exhibit remarkable
adenosine receptor affinity.[4] Reports from our labora-
tory[5] and from others[6] revealed that the possible route
for the synthesis of pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]
pyrimidine derivatives involves reaction of 5-amino-
4-imino-pyrazolo[3,4-d]pyrimidine with one-carbon
via dehydrative cyclization of the 4-acylhydrazino-
pyrazolo[3,4-d]pyrimidines were reported to give the
corresponding pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimi-
dines.[7] In the light of these findings and in continuation
of our ongoing research work on the chemistry of
hydrazonoyl halides,[8–23] it was thought interesting to
synthesize new series of pyrazolo[3,4-d]pyrimidine and
pyrazolo[4,3-e][1,2,4]triazolo[3,4-c]pyrimidine
deriva-
tives. Evaluation of antimicrobial activity against some
microorganisms was investigated.
J Heterocyclic Chem. 2019;1–21.
wileyonlinelibrary.com/journal/jhet
© 2019 Wiley Periodicals, Inc.
1

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HASSANEEN ET AL.
Our interest in developing a new synthsis of
of the corresponding N-phenyl-substituted benzenecarbo-
hydrazonoyl chlorides 1a-d (prepared by stirring of the
corresponding hydrazide with carbon tetrachloride and
triphenylphosphine in acetonitrile)[25] with malononitrile
in ethanol in the presence of sodium ethoxide
following the procedure we have previously reported for
synthesis of 5-amino-1,3-diphenyl-pyrazole-4-carbonitrile
2 (Scheme 1).[26] Elemental and spectral information ver-
ified the structures of the latter products (see Section 4).
For example, IR spectrum of 3 showed bands at ν 3430,
these two ring systems results from the fact that
some derivatives of both pyrazolo[3,4-d][1,2,4]triazolo
[1,5-c]pyrimidine and pyrazolo[4,3-e][1,2,4]triazolo
[3,4-c]pyrimidine derivatives exhibit interesting phar-
macological activities[24]; for example, several 3- and/or
5-substituted 7H-pyrazolo[4,3-e][1,2,4]triazolo[3,4-c]pyrim-
idines were reported to be potent xantheine oxidase
(XO) inhibitors.[24] Also, pyrazolo[3,4-d][1,2,4]triazolo
[1,5-c]pyrimidine is one of the structural requirements for
compounds that have as selective antagonists for human
A2A and A3 adenosine receptor subtypes.[6]
1
3320 (NH2) and 2238 (CN) cm−1. Its H NMR spectrum
revealed the presence of two singlet signals at δ 3.81 (3H,
CH3O) and at δ 6.75 (2H, NH2), in addition to multiplet
signal at δ 7.04-7.85 (9H) revealed to aromatic protons.
Reaction of the compounds 2-5 with triethylortho-
formate in acetic anhydride at reflux yielded the
corresponding N-ethoxymethylene derivatives 6-9
(Scheme 2). Elemental and spectral information verified
the structures of the latter products (see Section 4). For
example, 1H NMR spectrum of 7 revealed the presence of
triplet signal at δ 1.27 (3H, J = 7 Hz, CH3CH2), quartet
signal at δ 4.30 (2H, J = 7 Hz, CH2CH3), and two singlet
signals at δ 3.80 (3H, CH3O) and 8.59 (s, 1H, CH), in
addition to multiplet signal at δ 7.07-7.91 (9H) assignable
to aromatic protons.
2 | RESULTS AND DISCUSSION
The starting compounds, namely, 5-amino-1,3-dia-
rylpyrazole-4-carbonitrile 2-5, were prepared via reaction
Stirring of the compound 6-9 in ethanol at room tem-
perature with hydrazine hydrate furnished 3-amino-
4-imino-pyrazolo[3,4-d]pyrimidines 10-13, respectively
(Scheme 2). Refluxing the mixture of each of the com-
pounds 10-13 and hydrazine hydrate in ethanol for
2
hours, 4-hydrazino-1,3-diarylpyrazolo[3,4-d]pyrimi-
dines 14-17 were produced, respectively (Scheme 2). The
SCHEME 1 Synthesis of 5-amino-1,3-diarylpyrazole-
4-carbonitriles
SCHEME 2 Synthesis of 4-hydrazino-
1,3-diarylpyrazolo[3,4-d]pyrimidines

HASSANEEN ET AL.
3
methyl and vinyl-H, respectively. It also featured two
exchangeable singlet signals at 5.67 and 7.57 for the
respective NH2 and NH. The multiplet signal at 7.30-8-06
is assigned to aromatic protons.
The structures of compounds 14-17 were confirmed
chemically. For example, the reaction of each of the com-
pounds 14-17 with aromatic aldehydes in ethanol in the
presence of acetic acid as a catalyst yielded the
corresponding aldehyde N-aryl- and N-hetero-hydrazones
18-21 (Scheme 3). The structures of the latter products
were confirmed by elemental and spectral analyses. For
1
example, H NMR spectrum of 19B showed four doublet
signals at 7.03, 7.40, 7.50, and 7.53 for the aromatic pro-
tons of two para-substituted aryl groups and mutiplet sig-
nal 7.60-8-06 assigned to phenyl protons, four
characteristic singlet signals at δ 2.37 for CH3, at 3.83 for
CH3O, at 8.43 for CH, and at 8.47 for CH, and one
exchangeable singlet signal at δ 12.03 for NH.
Oxidation of each of the compounds 19-21 with
ferric chloride in ethanol resulted in the formation
of the corresponding 1,3,6-triarylpyrazolo[3,4-d][1,2,4]
triazolo[3,4-e]pyrimidines 22-24 (Scheme 3). The forma-
tion of compounds 22-24 is assumed to be via oxidation
of compounds 18-21 that affords the corresponding
nitrilimines followed by in situ 1,5-electrocyclization.
The formation of the latter seems to result via oxidation
of 19-21 to yield the corresponding nitrilimines that
underwent in situ 1,5-electrocyclization and gave 22-24.
This suggested pathway is compatible with literature
reports on oxidation of aldehyde N-hetarylhydrazones
and cyclization of N-hetaryl nitrilimines.[28]
FIGURE 1 Mechanism of Dimroth rearrangement
When the latter compounds 22-24 were heated at
reflux in ethanol in the presence of sodium acetate as a
base catalyst, they underwent Dimroth rearrangement
and gave the 7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]
pyrimidine derivatives 25-27 (Figure 2). The structures of
the latter products were confirmed by their alternate syn-
thesis. Thus, reaction of each of compounds 10-13 with
the appropriate acyl chloride yielded products that
proved identical in all respects (mp, IR, Ms) with those
obtained above from 22-24 (Scheme 4).
SCHEME 3 Synthesis of 1,3,6-triarylpyrazolo[3,4-d][1,2,4]
triazolo[3,4-e]pyrimidines
Treatment of hydrazine 14-17 in the refluxing ethanol
with the appropriate ketone in the presence of few drops
of acetic acid gave the corresponding hydrazones 28-31
(Scheme 5). The structures of isolated products were
conversion of compounds 10-13 into 14-17 seems to be
compatible with literature reported[27] that 3-amino-
4-imino-pyrazolo[3,4-d]pyrimidines undergo Dimroth
rearrangement via base-catalyzed tandem ring opening
and ring closure as shown in Figure 1 to give the
corresponding 4-hydrazino-pyrazolo[3,4-d]pyrimidines
14-17. The structures of the products 10-13 and 14-17
were elucidated on the basis of the elemental analyses
1
identified by their elemental and spectroscopic (IR, H
NMR, 13C NMR, and MS) analyses (see Section 4). For
1
example, the H NMR spectrum of 29A revealed three
singlet signals at δ 2.51 (3H, CH3), 3.81 (s, CH3O), and
8.60 (1H, CH) and multiplet signal at δ 6.99-8.10 (13H)
revealed to aromatic protons.
The reactions of the 3-amino-4-imino-pyrazolo[3,4-d]
pyrimidines 11-13 with the nitrilimines (generated in
1
and spectral data. For example, H NMR spectrum of 12
showed two singlet signals at δ 2.38 and 8.17 assigned to

4
HASSANEEN ET AL.
FIGURE 2 Mechanism of base-catalyzed rearrangement of
22-24 into 25-27
SCHEME 5 Synthesis of hydrazone derivatives 28-31
2-aminopyridine with α-oxohydrazonoyl halides and
α-haloketones and esters) (Scheme 7),[31,32] the interme-
diate 33-35A is not expected to be formed, and accord-
ingly, structure 36-38 was discarded. Furthermore, the
electronic absorption spectrum of the isolated products
excludes the hydrazone structure 39-41 since they rev-
ealed a characteristic absorption maxima at 361 (logε
4.43) and 400 (logε 4.40) nm assignable to an arylazo
chromophore.[33,34] Accordingly, the products obtained
from the reaction of 11-13 with 32 were assigned struc-
ture 42-44. Also, the structures of products were identi-
fied, on the basis of their elemental analysis and spectral
(IR, NMR, and MS) data (Section 4).
SCHEME 4 Synthesis of 7H-pyrazolo[4,3-e][1,2,4]triazolo
[1,5-c]pyrimidine derivatives 25-27
3 | ANTIMICROBIAL SCREENING
The antibacterial and antifungal activities of new synthe-
sized compounds were studied by the disk diffusion
method. The antibacterial activities were done on the fol-
lowing pathogenic organisms: the Gram-positive bacteria
Staphylococcus aureus and Bacillus subtilis, the Gram-
negative bacteria Escherichia coli and Pseudomonas
aeruginosa. Moreover, antifungal activities against Asper-
gillus flavus and Candida albicans were studied. The syn-
thesized compounds were used at the concentration of
20 mg/mL using dimethyl sulfoxide (DMSO) as a solvent.
The Ampicillin 10 μL/disk was used as a standard
antibacterial agent and the Amphotericin B 20 μg/mL as
standard antifungal agent. The results presented in
Table 1 suggest that the most potent compounds 5, 28D,
29B, and 31D exhibited antimicrobial activity.
situ by base-catalyzed dehydrohalogenation of the
hydrazonoyl halides 32) were next examined (Scheme 6).
In our hands, reaction of 11-13 with each of the
α-ketohydrazonoyl halides 32 in refluxing chloroform in
the presence of triethylamine yielded, in each case, one
isolated product pyrazolopyrimidotriazine derivatives 42-
44. The IR spectra of the isolated products revealed the
absence of the carbonyl absorption bands, thus excluding
the two possible nucleophilic substitution structures 33-
35A and 33-35B. The results of elemental analyses of the
products were found to be consistent with the two iso-
meric structures 36-38 and 39-41 and its tautomeric struc-
ture 42-44 (Scheme 6). Since the imino nitrogen is known
to be more basic and in turn more nucleophilic than that
of the amino group[29,30] (this reaction seem to follow the
same mechanism reported for the reactions of
In vitro susceptibility tests were performed to
evaluate minimum inhibitory concentration (MIC)

HASSANEEN ET AL.
5
measured by a broth dilution method.[35–37] MIC
values were determined for the highly efficient
antibacterial compounds using the most sensitive
microorganisms. Results illustrated in Table 2 indi-
cate that compound 28D achieved the lowest
MIC values (high efficient derivative) against the
sensitive bacterial strain B. subtilis and P. aeruginosa
with MIC values 40 and 60 μg/mL, respectively.
4 | EXPERIMENTAL
Melting points were determined on a Stuart melting
point apparatus and are uncorrected. The IR spectra
were measured as KBr pellets on a FTIR Bruker-
Vector 22 spectrophotometer. The 1H NMR and 13C
NMR spectra were recorded in CDCl3 or [D6] DMSO
on
a
Varian Mercury VXR 300 spectrometer
(300 MHz for 1H NMR and 75 MHz for 13C NMR)
using TMS as internal standard. Mass spectra were
measured on a Shimadzu GCMS-Q-1000 EX mass
spectrometer at 70 eV. The elemental analyses were
carried out at the Microanalytical Center, Cairo Uni-
versity using Automated analyzer CHNS, Vario EL
III, Elementar, Germany. The in vitro antimicrobial
testing was performed at Microanalytical Center,
Cairo University. The agar disk diffusion method and
a panel of standard strains (S. aureus ATCC 6588,
B. subtilis CMGB 215, E. coli ATCC 11775,
P. aeuroginosa ATCC 15442, A. flavus Link, and
C. albicans ATCC 7102) were employed. Compounds
2, 6, 10, and 14 were prepared using the reported
procedures.[26]
4.1 | 5-Amino-3-aryl-1-phenyl-1H-
pyrazole-4-carbonitrile derivatives (3-5)
Malonitrile (1.3 g, 20.0 mmol) was added to ethanol
sodium ethoxide solution (prepared from sodium metal
[0.46 g, 20.0 mmol] and absolute ethanol [20 mL]). The
mixture was stirred for 10 minutes, and hydrazonoyl
chloride 1b-d (20.0 mmol) was added. The mixture was
SCHEME 6 Reaction of the 3-amino-4-imino-pyrazolo[3,4-d]
pyrimidines with α-ketohydrazonoyl halides
SCHEME 7 Reaction of 2-aminopyridine
with α-oxohydrazonoyl halides and
α-haloketones and esters

6
HASSANEEN ET AL.

HASSANEEN ET AL.
7
TABLE 2 MIC of compounds 5, 28D, 29B, 31D against the sensitive microorganism
MIC, μg/mL
G+
G−
Fungi
Compound
Bacillus subtilis
Pseudomonas aeruginosa
Escherichia coli
Candida albicans
5
182
40
232
60
--
--
--
--
420
420
600
840
28D
29B
31D
134
88
142
102
Abbreviation: MIC, minimum inhibitory concentration.
stirred for further 15 minutes at room temperature and
then left overnight. Solids that precipitated were col-
lected, washed with water, and then crystallized from
suitable solvent.
C16H11ClN4 (294.07): C, 65.20; H, 3.76; Cl, 12.03; N,
19.01. Found: C, 65.13; H, 3.78; Cl, 12.11; N, 18.91.
4.2 | Ethyl-N-(3-aryl-4-cyano-1-phenyl-
1H-pyrazol-5-yl)formimidate derivatives
(7-9)
4.1.1 | 5-Amino-3-(4-methoxyphenyl)-
1-phenyl-1H-pyrazole-4-carbonitrile (3)
The appropriate 5-amino-3-aryl-1-phenyl-1H-pyrazole-
4-carbonitrile derivatives 3-5 (50.0 mmol) were dissolved in
acetic anhydride (50 mL). To the resulting solution, triethyl
orthoformate (7.40 g, 50.0 mmol) was added, the mixture
was refluxed for 5 hours, and the excess acetic anhydride
was distilled off under reduced pressure. The solid that pre-
cipitated on cooling was filtered, and the crude product was
crystallized from the suitable solvent to give 7-9.
Yield (81%); White crystals; mp 163ꢀC-165ꢀC (EtOH); IR
1
(νmax, cm−1) ν 3430 and 3320 (NH2) and 2238 (CN); H
NMR (300 MHz, DMSO-d6) δ 3.81 (s, 3H, CH3O), 6.75 (s,
2H, NH2) and 7.04-7.85 (m, 9H); 13C NMR (75 MHz,
DMSO-d6) δ 55.2, 71.1, 114.2, 115.7, 123.7, 124.2, 127.6,
127.8, 129.4, 137.4, 150.1, 152.8, 159.9; MS (EI, 70 eV) m/
z (%): 290 (M+, 100). Anal. Calcd. for C17H14N4O
(290): C, 70.33; H, 4.86; N, 19.30. Found: C, 70.30; H,
4.79; N, 19.27.
4.2.1 | Ethyl-N-(4-cyano-
3-(4-methoxyphenyl)-1-phenyl-1H-pyrazol-
5-yl)formimidate (7)
4.1.2 | 5-Amino-1-phenyl-3-(p-tolyl)-1H-
pyrazole-4-carbonitrile (4)
Yield (76%); White crystals; mp 127ꢀC-128ꢀC (CH3CN); IR
(νmax, cm−1) ν 2220 (CN); 1H NMR (300 MHz, DMSO-d6) δ
1.27 (t, J = 7 Hz, 3H, CH3CH2), 3.80 (s, 3H, CH3O), 4.30 (q,
J = 7 Hz, 2H, CH2CH3), 7.07-7.91 (m, 9H) and 8.59 (s, 1H,
CH); 13C NMR (75 MHz, DMSO-d6) δ 13.7, 55.2, 64.0, 79.10,
114.36, 115.10, 123.02, 123.69, 127.46, 127.82, 128.91, 137.63,
150.55, 151.70, 160.25, 162.19; MS (EI, 70 eV) m/z (%):
346 (M+, 100). Anal. Calcd. for C20H18N4O2 (346.14): C,
69.35; H, 5.24; N, 16.17. Found: C, 69.28; H, 5.21; N, 16.20.
Yield (85%); White crystals; mp 148ꢀC-150ꢀC (EtOH); IR
1
(νmax, cm−1) ν 3444 and 3300 (NH2) and 2222 (CN); H
NMR (300 MHz, DMSO-d6) δ 2.35 (s, 3H, CH3), 6.9 (s,
2H, NH2) and 7.28-7.78 (m, 9H); 13C NMR (75 MHz,
DMSO-d6) δ 20.7, 71.3, 113.4, 115.6, 124.2, 125.8, 127.9,
129.0, 137.4, 138.6, 144.2, 150.3, 152.8; MS (EI, 70 eV) m/
z (%): 274 (M+, 100). Anal. Calcd. for C17H14N4
(274.12): C, 74.43; H, 5.14; N, 20.42. Found: C, 74.32; H,
5.06; N, 20.51.
4.2.2 | Ethyl-N-(4-cyano-1-phenyl-3-(p-
tolyl)-1H-pyrazol-5-yl)formimidate (8)
4.1.3 | 5-Amino-3-(4-chlorophenyl)-
1-phenyl-1H-pyrazole-4-carbonitrile (5)
Yield (80%); White crystals; mp 126ꢀC-128ꢀC (EtOH); IR
(νmax, cm−1) ν 2214 (CN); 1H NMR (300 MHz, DMSO-d6)
δ 1.29 (t, J = 7 Hz, 3H, CH3CH2), 2.30 (s, 3H, CH3), 4.27
(q, J = 7 Hz, 2H, CH2CH3), 7.00-7.86 (m, 9H) and 8.63 (s,
Yield (88%); White crystals; mp 174ꢀC-176ꢀC (CH3CN);
IR (νmax, cm−1) ν 3436 and 3309 (NH2) and 2230 (CN);
MS (EI, 70 eV) m/z (%): 294 (M+, 100). Anal. Calcd. for

8
HASSANEEN ET AL.
1H, CH); MS (EI, 70 eV) m/z (%): 330 (M+, 4.1), 77 (100).
Anal. Calcd. for C20H18N4O (330.15): C, 72.71; H, 5.49; N,
16.96. Found: C, 72.62; H, 5.52; N, 16.99.
(300 MHz, DMSO-d6) δ 2.38 (s, 3H, CH3), 5.67 (s, 2H,
NH2), 7.30-8.06 (m, 9H), 7.57 (s, 1H, NH) and 8.17 (s, 1H,
CH); 13C NMR (75 MHz, DMSO-d6) δ 20.85, 111.65,
117.31, 121.78, 126.69, 128.60, 128.80, 128.97, 129.32,
138.20, 147.40, 148.91, 151.28, 159.53; MS (EI, 70 eV) m/z
(%): 316 (M+, 100). Anal. Calcd. for C18H16N6 (316.14): C,
68.34; H, 5.10; N, 26.56. Found: C, 68.29; H, 5.03; N, 26.58.
4.2.3 | Ethyl-N-(3-(4-chlorophenyl)-
4-cyano-1-phenyl-1H-pyrazol-5-yl)
formimidate (9)
Yield (78%); White crystals; mp 136ꢀC-138ꢀC (Dioxane); IR
(νmax, cm−1) ν 2235 (CN); 1H NMR (300 MHz, DMSO-d6) δ
1.27 (t, J = 7 Hz, 3H, CH3), 4.28 (q, J = 7 Hz, 2H, CH2),
7.43-7.97 (m, 9H) and 8.61 (s, 1H, CH); 13C NMR (75 MHz,
DMSO-d6) δ 13.74, 64.11, 114.66, 123.80, 127.65, 128.09,
128.98, 129.12, 129.33, 134.28, 137.45, 149.41, 152.05, 160.00,
162.49; MS (EI, 70 eV) m/z (%): 350 (M+, 100). Anal. Calcd.
for C19H15ClN4O (350.09): C, 65.05; H, 4.31; Cl, 10.11; N,
15.97. Found: C, 65.12; H, 4.26; Cl, 10.04; N, 15.92.
4.3.3 | 3-(4-Chlorophenyl)-4-imino-
1-phenyl-1,4-dihydro-5H-pyrazolo[3,4-d]
pyrimidin-5-amine (13)
Yield (91%); Yellow crystals; mp 188ꢀC-190ꢀC (DMF); IR
(νmax, cm−1) ν 3354, 3348, 3321 (NH, NH2);MS (EI,
70 eV) m/z (%): 336 (M+, 100). Anal. Calcd. for
C17H13ClN6 (336.09): C, 60.63; H, 3.89; Cl, 10.53; N,
24.95. Found: C, 60.58; H, 3.84; Cl, 10.58; N, 24.99.
4.3 | 3-Aryl-4-imino-1-phenyl-
1,4-dihydro-5H-pyrazolo[3,4-d]pyrimidin-
5-amine derivatives (11-13)
4.4 | 4-Hydrazinyl-3-aryl-1-phenyl-1H-
pyrazolo[3,4-d]pyrimidine derivatives
(15-17)
A mixture of the appropriate ethyl-N-(3-aryl-4-cyano-
1-phenyl-1H-pyrazol-5-yl)formimidate 7-9 (50 mmol) and
hydrazine hydrate (5.0 g, 100 mmol) was stirred for
6 hours in ethanol (200 mL) at room temperature. The
solid that was separated and filtered, dried, and crystal-
lized from the suitable solvent gave 11-13.
To a solution of 3-aryl-4-imino-1-phenyl-1,4-dihydro-5H-
pyrazolo[3,4-d]pyrimidin-5-amine
derivatives
11-13
(20.0 mmol) in ethanol (50 mL), hydrazine hydrate (5 mL)
was added, and the reaction mixture was refluxed for
6 hours. The solid that precipitated was filtered and crys-
tallized from dioxane to give corresponding 4-hydrazinyl-
3-aryl-1-phenyl-1H-pyrazolo[3,4-d]pyrimidine 15-17.
4.3.1 | 4-Imino-3-(4-methoxyphenyl)-
1-phenyl-1,4-dihydro-5H-pyrazolo[3,4-d]
pyrimidin-5-amine (11)
4.4.1 | 4-Hydrazinyl-
3-(4-methoxyphenyl)-1-phenyl-1H-pyrazolo
[3,4-d]pyrimidine (15)
Yield (82%); Yellow crystals; mp 192ꢀC-194ꢀC (Dioxane); IR
(νmax, cm−1) ν 3350, 3343, 3316 (NH, NH2); 1H NMR
(300 MHz, DMSO-d6) δ, 3.81 (s, 3H, CH3O), 5.67 (s, 2H,
NH2), 7.49 (s, 1H, NH), 7.03-8.06 (m, 9H) and 8.17 (s, 1H,
CH); 13C NMR (75 MHz, DMSO-d6) δ 55.11, 102.28, 113.62,
121.76, 124.57, 126.64, 128.97, 130.14, 138.25, 138.25, 147.24,
149.10, 151.32, 159.66; MS (EI, 70 eV) m/z (%): 332 (M+,
17.8), 80 (100). Anal. Calcd. for C18H16N6O (332.14): C,
65.05; H, 4.85; N, 25.29. Found: C, 64.97; H, 4.86; N, 25.32.
Yield (86%); Pale yellow crystals; mp 194ꢀC-196ꢀC; IR
1
(νmax, cm−1) ν 3429, 3316, and 3281 (NH, NH2); H NMR
(300 MHz, DMSO-d6) δ 3.85 (s, 3H, CH3O), 4.38 (s, 2H,
NH2), 7.08-8.14 (m, 9H), 7.54 (s, 1H, NH) and 8.20 (s, 1H,
CH); 13C NMR (75 MHz, DMSO-d6) δ 50.3, 104.5, 112.4,
118.9, 124.6, 125.9, 127.8, 129.2, 135.8, 139.1, 144.5, 153.2,
161.6, 165.3; MS (EI, 70 eV) m/z (%): 332 (M+, 100). Anal.
Calcd. for C18H16N6O (332.14): C, 65.05; H, 4.85; N,
25.29. Found: C, 64.90; H, 4.80; N, 25.25.
4.3.2 | 4-Imino-1-phenyl-3-(p-tolyl)-
1,4-dihydro-5H-pyrazolo[3,4-d]pyrimidin-
5-amine (12)
4.4.2 | 4-Hydrazinyl-1-phenyl-3-(p-tolyl)-
1H-pyrazolo[3,4-d]pyrimidine (16)
Yield (86%); Yellow crystals; mp 194ꢀC-196ꢀC (Dioxane);
Yield (83%); Yellow crystals; mp 194ꢀC-196ꢀC; IR (νmax
cm−1) ν 3428, 3331, and 3276 (NH, NH2); 1H NMR
,
1
IR (νmax, cm−1) ν 3347, 3335, 3310 (NH, NH2); H NMR

HASSANEEN ET AL.
9
(300 MHz, DMSO-d6) δ 2.38 (s, 3H, CH3), 4.34 (s, 2H,
NH2), 7.02-8.11 (m, 9H), 7.57 (s, 1H, NH) and 8.23 (s, 1H,
CH); 13C NMR (75 MHz, DMSO-d6) δ 21.0, 104.3, 112.5,
118.7, 124.5, 125.2, 128.6, 129.0, 135.3, 140.5, 144.8, 153.4,
161.1, 164.7; MS (EI, 70 eV) m/z (%): 316 (M+, 100). Anal.
Calcd. for C18H16N6 (316.14): C, 68.34; H, 5.10; N, 26.56.
Found: C, 68.22; H, 5.99; N, 26.50.
7.04-8.11 (m, 14H), 8.45 (s, 1H, CH), 8.48 (s, 1H, CH) and
11.95 (s, 1H, NH) ; 13C NMR (75 MHz, DMSO-d6) δ
55.10, 100.52, 113.22, 120.63, 121.38, 122.11, 124.56,
126.57, 127.90, 128.95, 129.87, 130.63, 135.19, 138.21,
146.94, 147.65, 150.45, 153.69, 159.64; MS (EI, 70 eV) m/z
(%): 420 (M+, 49.9), 317 (100). Anal. Calcd. for
C25H20N6O (420.17): C, 71.41; H, 4.79; N, 19.99.
Found: C, 71.32; H, 4.81; N, 19.90.
4.4.3 | 3-(4-Chlorophenyl)-4-hydrazinyl-
1-phenyl-1H-pyrazolo[3,4-d]pyrimidine (17)
4.5.3 | 3-(4-Methoxyphenyl)-
4-(2-(4-methylbenzylidene)hydrazinyl)-
1-phenyl-1H-pyrazolo[3,4-d]-
pyrimidine (19B)
Yield (87%); Yellow crystals; mp 194ꢀC-196ꢀC; IR (νmax
,
cm−1) ν 3420, 3325, and 3269 (NH, NH2); MS (EI, 70 eV)
m/z (%): 336 (M+, 100). Anal. Calcd. for C17H13ClN6
(336.09): C, 60.63; H, 3.89; Cl, 10.53; N, 24.95. Found: C,
60.53; H, 3.87; Cl, 10.50; N, 24.90.
1
Yield (80%); Yellow crystals; mp 212ꢀC-214ꢀC (DMF); H
NMR (300 MHz, DMSO-d6) δ 2.37 (s, 3H, CH3), 3.83 (s,
3H, CH3O), 7.03 (d, 2H), 7.40 (d, 2H), 7.50 (d, 2H), 7.53
(d, 2H), 7.60-8.10 (m, 5H), 8.43 (s, 1H, CH), 8.47 (s, 1H,
CH) and 12.03 (s, 1H, NH); 13C NMR (75 MHz, DMSO-
d6) δ 20.9, 55.2, 100.6, 113.3, 121.4, 122.2, 124.6, 126.6,
126.8, 127.9, 128.7, 129.0, 129.2, 130.6, 132.5, 138.2, 146.9,
147.8, 153.8, 159.7; MS (EI, 70 eV) m/z (%): 434 (M+,
50.3), 317 (100) . Anal. Calcd. for C26H22N6O (434.19): C,
71.87; H, 5.10; N, 19.34. Found: C, 71.70; H,
5.20; N, 19.41.
4.5 | 3-Aryl-4-(2-benzylidenehydrazinyl)-
1-phenyl-1H-pyrazolo[3,4-d]pyrimidine
derivatives (18-21)
Refluxing of mixture of the appropriate hydrazinyl com-
pound 14-17 (5.0 mmol), the appropriate aldehyde
(5.0 mmol) and a few drops of acetic acid in ethanol
(30 mL) for 6 hours. The reaction mixture was cooled,
and the precipitate that separated was collected and crys-
tallized from the suitable solvent to give the
corresponding benzylidene hydrazinyl derivatives 18-21.
4.5.4 | 4-(2-(4-Methoxybenzylidene)
hydrazinyl)-3-(4-methoxyphenyl)-1-phenyl-
1H-pyrazolo[3,4-d]-pyrimidine (19C)
1
4.5.1 | 4-(2-((1H-Indol-3-yl)methylene)
hydrazinyl)-1,3-diphenyl-1H-pyrazolo[3,4-d]
pyrimidine (18H)
Yield (79%); Yellow crystals; mp 197ꢀC-198ꢀC (DMF); H
NMR (300 MHz, DMSO-d6) δ 3.81 (s, 3H, CH3O), 3.83 (s,
3H, CH3O), 7.00 (d, 2H), 7.23 (d, 2H), 7.40 (d, 2H), 7.50
(d, 2H), 7.61-8.11 (m, 5H), 8.42 (s, 1H, CH), 8.48 (s, 1H,
CH) and 11.95 (s, 1H, NH); 13C NMR (75 MHz, DMSO-
d6) δ 55.1, 55.2, 100.5, 113.2, 114.0, 120.6, 122.1, 124.6,
126.7, 127.8, 128.2, 128.9, 129.5, 130.6, 138.2, 146.8, 147.6,
150.3, 159.6; MS (EI, 70 eV) m/z (%): 450 (M+, 39.1),
317 (100). Anal. Calcd. for C26H22N6O2 (450.18): C,
69.32; H, 4.92; N, 18.66. Found: C, 69.20; H,
5.01; N, 18.75.
Yield (75%); Yellow crystals; mp 222ꢀC-224ꢀC (Dioxane); 1H
NMR (300 MHz, DMSO-d6) δ 7.21-8.12 (m, 14H), 8.47 (s, 1H,
CH), 8.54 (s, 1H, CH), 8.67 (s, 1H, CH-Indol), 11.41 (s, 1H,
NH) and 11.63 (s, 1H, NH); 13C NMR (75 MHz, DMSO-d6) δ
100.9, 111.7, 112.5, 120.4, 122.1, 122.2, 124.5, 126.6, 127.8,
128.1, 128.5, 129.0, 129.1, 131.5, 132.2, 137.1, 138.2, 144.4,
146.8, 148.2, 150.2, 151.5; MS (EI, 70 eV) m/z (%): 429 (M+,
29.3), 286 (100) . Anal. Calcd. for C26H19N7 (429.17): C,
72.71; H, 4.46; N, 22.83. Found: C, 72.76; H, 4.42; N, 22.80.
4.5.5 | 4-(2-(4-Chlorobenzylidene)
hydrazinyl)-3-(4-methoxyphenyl)-1-phenyl-
1H-pyrazolo[3,4-d]pyrimidine (19D)
4.5.2 | 4-(2-Benzylidenehydrazinyl)-
3-(4-methoxyphenyl)-1-phenyl-1H-pyrazolo
[3,4-d]pyrimidine (19A)
Yield (83%); Yellow crystals; mp 206ꢀC-208ꢀC (DMF); MS
(EI, 70 eV) m/z (%): 454 (M+, 41.3), 317 (100) . Anal.
Calcd. for C25H19ClN6O (454.13): C, 66.01; H, 4.21; Cl,
7.79; N, 18.47. Found: C, 65.95; H, 4.27; Cl, 7.84; N, 18.51.
1
Yield (83%); White crystals; mp 180ꢀC-182ꢀC (DMF); H
NMR (300 MHz, DMSO-d6) δ 3.83 (s, 3H, CH3O),

10
HASSANEEN ET AL.
4.5.6 | 3-(4-Methoxyphenyl)-
4-(2-(4-nitrobenzylidene)hydrazinyl)-
1-phenyl-1H-pyrazolo[3,4-d]
pyrimidine (19E)
120.4, 122.1, 122.5, 124.5, 126.7, 128.5, 128.9, 130.5, 131.4,
137.1, 138.3, 144.5, 146.7, 148.0, 150.8, 151.4, 159.8; MS
(EI, 70 eV) m/z (%): 459 (M+, 13.21), 317 (100) . Anal.
Calcd. for C27H21N7O (459.18): C, 70.57; H, 4.61; N,
21.34. Found: C, 70.50; H, 4.63; N, 21.38.
1
Yield (79%); Yellow crystals; mp 240ꢀC-242ꢀC (DMF); H
NMR (300 MHz, DMSO-d6) δ 3.76 (s, 3H, CH3O),
7.03-8.09 (m, 13H), 8.46 (s, 1H, CH), 8.56 (s, 1H, CH) and
11.85 (s, 1H, NH); 13C NMR (75 MHz, DMSO-d6) δ 55.2,
101.6, 113.7, 120.8, 122.3, 126.8, 127.0, 127.6, 129.7, 130.9,
133.1, 138.5, 144.5, 146.1, 146.8, 150.8, 153.7, 161.3, 161.9;
MS (EI, 70 eV) m/z (%): 465 (M+, 59.8), 317 (100) . Anal.
Calcd. for C25H19N7O3 (465.15): C, 64.51; H, 4.11; N,
21.06. Found: C, 64.43; H, 4.28; N, 21.20.
4.5.10 | 4-(2-Benzylidenehydrazinyl)-
1-phenyl-3-(p-tolyl)-1H-pyrazolo[3,4-d]
pyrimidine (20A)
Yield (78%); Yellow crystals; mp 194ꢀC-196ꢀC (DMF); IR
(νmax, cm−1) ν 3336 (NH) cm−1; 1H NMR (300 MHz,
DMSO-d6) δ 2.37 (s, 3H, CH3), 7.28-8.11 (m, 14H), 8.37 (s,
1H, CH), 8.45 (s, 1H, CH) and 12.01 (s, 1H, NH); 13C NMR
(75 MHz, DMSO-d6) δ 20.7, 100.6, 120.7, 121.4, 122.4, 126.3,
127.9, 128.5, 128.9, 129.1, 129.3, 133.6, 137.6, 138.2, 145.1,
147.7, 150.5, 153.8, 154.9; MS (EI, 70 eV) m/z (%): 404 (M+,
51.8), 77 (100). Anal. Calcd. for C25H20N6 (404.17): C,
74.24; H, 4.98; N, 20.78. Found: C, 74.13; H, 4.88; N, 20.75.
4.5.7 | 3-(4-Methoxyphenyl)-1-phenyl-
4-(2-(pyridin-4-ylmethylene)hydrazinyl)-
1H-pyrazolo[3,4-d]-pyrimidine (19F)
1
Yield (75%); Yellow crystals; mp 242ꢀC-244ꢀC (DMF); H
NMR (300 MHz, DMSO-d6) δ 3.83 (s, 3H, CH3O),
7.10-8.20 (m, 13H), 8.40 (s, 1H, CH), 8.51 (s, 1H, CH) and
11.80 (s, 1H, NH); 13C NMR (75 MHz, DMSO-d6) δ 55.5,
114.1, 120.8, 123.1, 126.0, 126.5, 127.4, 129.5, 130.8, 133.5,
138.8, 143.7, 146.8, 148.8, 153.5, 153.6, 161.9, 165.6; MS
(EI, 70 eV) m/z (%): 421 (M+, 53.9), 343 (100) . Anal.
Calcd. for C24H19N7O (421.17): C, 68.40; H, 4.54; N,
23.26. Found: C, 68.31; H, 4.51; N, 23.29.
4.5.11 | 4-(2-(4-Methylbenzylidene)
hydrazinyl)-1-phenyl-3-(p-tolyl)-1H-
pyrazolo[3,4-d]pyrimidine (20B)
Yield (76%); Yellow crystals; mp 189ꢀC-190ꢀC (CH3CN);
MS (EI, 70 eV) m/z (%): 418 (M+, 44.5), 300 (100) . Anal.
Calcd. for C26H22N6 (418.19): C, 74.62; H, 5.30; N, 20.08.
Found: C, 74.59; H, 5.24; N, 20.17.
4.5.8 | 3-(4-Methoxyphenyl)-1-phenyl-
4-(2-(thiophen-2-ylmethylene)hydrazinyl)-
1H-pyrazolo[3,4-d]-pyrimidine (19G)
4.5.12 | 4-(2-(4-Methoxybenzylidene)
hydrazinyl)-1-phenyl-3-(p-tolyl)-1H-
pyrazolo[3,4-d]pyrimidine (20C)
1
Yield (78%); Yellow crystals; mp 218ꢀC-220ꢀC (DMF); H
NMR (300 MHz, DMSO-d6) δ 3.79 (s, 3H, CH3O), 7.03-8.17
(m, 12H), 8.42 (s, 1H, CH), 8.50 (s, 1H, CH) and 11.64 (s,
1H, NH); MS (EI, 70 eV) m/z (%): 426 (M+, 47.6), 317 (100)
. Anal. Calcd. for C23H18N6OS (426.13): C, 64.77; H, 4.25; N,
19.71; S, 7.52. Found: C, 64.60; H, 4.23; N, 19.68; S, 7.58.
Yield (75%); Yellow crystals; mp 188ꢀC-190ꢀC (CH3CN); 1H
NMR (300 MHz, DMSO-d6) δ 2.38 (s, 3H, CH3), 3.81 (s, 3H,
CH3O), 7.00-8.09 (m, 13H), 8.34 (s, 1H, CH), 8.38 (s, 1H,
CH) and 12.00 (s, 1H, NH); 13C NMR (75 MHz, DMSO-d6)
δ 20.9, 55.2, 100.7, 114.0, 120.6, 122.2, 126.9, 127.8, 128.4,
128.9, 129.1, 129.3, 129.5, 137.9, 138.2, 147.0, 147.7, 150.4,
153.5, 160.8; MS (EI, 70 eV) m/z (%): 434 (M+, 38.3),
301 (100). Anal. Calcd. for C26H22N6O (434.19): C, 71.87; H,
5.10; N, 19.34. Found: C, 71.72; H, 5.19; N, 19.39.
4.5.9 | 4-(2-((1H-Indol-3-yl)methylene)
hydrazinyl)-3-(4-methoxyphenyl)-1-phenyl-
1H-pyrazolo[3,4-d]pyrimidine (19H)
Yield (73%); Yellow crystals; mp 216ꢀC-218ꢀC (Dioxane);
4.5.13 | 4-(2-(4-Chlorobenzylidene)
hydrazinyl)-1-phenyl-3-(p-tolyl)-1H-
pyrazolo[3,4-d]pyrimidine (20D)
1
IR (νmax, cm−1) ν 3331 (NH) cm−1; H NMR (300 MHz,
DMSO-d6) δ 3.85 (s, 3H, CH3O), 7.05-8.11 (m, 13H), 8.49
(s, 1H, CH), 8.54 (s, 1H, CH), 8.70 (s, 1H, CH-Indol),
11.40 (s, 1H, NH) and 11.63 (s, 1H, NH); 13C NMR
(75 MHz, DMSO-d6) δ 55.1, 100.7, 111.7, 112.5, 113.2,
Yield (77%); Yellow crystals; mp 208ꢀC-210ꢀC (DMF); MS
(EI, 70 eV) m/z (%): 438 (M+, 41.5), 300 (100). Anal.

HASSANEEN ET AL.
11
Calcd. for C25H19ClN6 (438.14): C, 68.41; H, 4.36; Cl,
8.08; N, 19.15. Found: C, 68.29; H, 4.40; Cl, 8.10; N, 19.19.
1H, CH), 8.52 (s, 1H, CH), 8.68 (s, 1H, CH-Indole), 11.39
(s, 1H, NH) and 11.63 (s, 1H, NH); 13C NMR (75 MHz,
DMSO-d6) δ 20.9, 100.8, 111.6, 112.5, 120.4, 122.2, 123.0,
124.5, 126.8, 128.3, 129.0, 129.4, 130.7, 131.4, 137.8, 138.2,
144.4, 146.9, 148.1, 150.1, 151.5, 159.2; MS (EI, 70 eV) m/
z (%): 443 (M+, 13.96), 300 (100). Anal. Calcd. for
C27H21N7 (443.19): C, 73.12; H, 4.77; N, 22.11. Found: C,
73.19; H, 4.72; N, 22.14.
4.5.14 | 4-(2-(4-Nitrobenzylidene)
hydrazinyl)-1-phenyl-3-(p-tolyl)-1H-
pyrazolo[3,4-d]pyrimidine (20E)
1
Yield (82%); Yellow crystals; mp 260ꢀC-262ꢀC (DMF); H
NMR (300 MHz, DMSO-d6) δ 2.30 (s, 3H, CH3), 7.00-8.05
(m, 13H), 8.52 (s, 1H, CH), 8.60 (s, 1H, CH) and 11.95 (s,
1H, NH); 13C NMR (75 MHz, DMSO-d6) δ 21.5, 103.8,
114.0, 118.9, 120.3, 124.5, 125.6, 128.8, 129.0, 129.3, 130.1,
132.4, 138.1, 140.3, 143.2, 146.5, 151.0, 153.6, 161.2; MS
(EI, 70 eV) m/z (%): 449 (M+, 66.8), 300 (100). Anal.
Calcd. for C25H19N7O2 (449.16): C, 66.81; H, 4.26; N,
21.81. Found: C, 66.72; H, 4.28; N, 21.89.
4.5.18 | 4-(2-Benzylidenehydrazinyl)-
3-(4-chlorophenyl)-1-phenyl-1H-pyrazolo
[3,4-d]pyrimidine (21A)
Yield (75%); Yellow crystals; mp 202ꢀC-204ꢀC (CH3CN);
MS (EI, 70 eV) m/z (%): 424 (M+, 61.6), 77 (100). Anal.
Calcd. for C24H17ClN6 (424.12): C, 67.84; H, 4.03; Cl,
8.34; N, 19.78. Found: C, 67.76; H, 4.12; Cl, 8.10; N, 19.73.
4.5.15 | 1-Phenyl-4-(2-(pyridin-
4-ylmethylene)hydrazinyl)-3-(p-tolyl)-1H-
pyrazolo[3,4-d]pyrimidine (20F)
4.5.19 | 3-(4-Chlorophenyl)-
4-(2-(4-methylbenzylidene)hydrazinyl)-
1-phenyl-1H-pyrazolo[3,4-d]
pyrimidine (21B)
1
Yield (80%); Yellow crystals; mp 248ꢀC-250ꢀC (DMF); H
NMR (300 MHz, DMSO-d6) δ 2.35 (s, 3H, CH3), 7.08-8.19
(m, 13H), 8.43 (s, 1H, CH), 8.56 (s, 1H, CH) and 11.82 (s,
1H, NH); 13C NMR (75 MHz, DMSO-d6) δ 22.0, 113.9,
117.8, 120.5, 120.8, 123.4, 125.1, 128.5, 129.7, 130.6, 131.6,
136.1, 141.3, 143.2, 149.8, 153.6, 164.5, 166.2; MS (EI,
70 eV) m/z (%): 405 (M+, 47.8), 327 (100). Anal. Calcd.
for C24H19N7 (405.17): C, 71.09; H, 4.72; N, 24.18.
Found: C, 70.90; H, 4.75; N, 24.25.
Yield (82%); Yellow crystals; mp 203ꢀC-204ꢀC (DMF);
1H NMR (300 MHz, DMSO-d6) δ 2.35 (s, 3H, CH3),
7.25-8.08 (m, 13H), 8.43 (s, 1H, CH), 8.50 (s, 1H, CH)
and 12.00 (s, 1H, NH); 13C NMR (75 MHz, DMSO-d6) δ
21.0, 100.6, 120.7, 121.5, 122.2, 126.3, 127.0, 127.9, 129.0,
129.1, 130.8, 132.4, 133.3, 138.0, 139.8, 145.8, 147.9,
150.6, 154.1; MS (EI, 70 eV) m/z (%): 438 (M+, 47.6),
77 (100). Anal. Calcd. for C25H19ClN6 (438.14): C,
68.41; H, 4.36; Cl, 8.08; N, 19.15. Found: C, 68.23; H,
4.38; Cl, 8.10; N, 19.01.
4.5.16 | 1-Phenyl-4-(2-(thiophen-
2-ylmethylene)hydrazinyl)-3-(p-tolyl)-1H-
pyrazolo[3,4-d]pyrimidine (20G)
4.5.20 | 3-(4-Chlorophenyl)-
4-(2-(4-methoxybenzylidene)hydrazinyl)-
1-phenyl-1H-pyrazolo[3,4-d]
pyrimidine (21C)
Yield (81%); Yellow crystals; mp 199ꢀC-200ꢀC (DMF); MS
(EI, 70 eV) m/z (%): 410 (M+, 69.8), 300 (100). Anal.
Calcd. for C23H18N6S (410.13): C, 67.30; H, 4.42; N,
20.47; S, 7.81. Found: C, 67.21; H, 4.45; N, 20.49; S, 7.79.
Yield (79%); Yellow crystals; mp 184ꢀC-185ꢀC (CH3CN);
1H NMR (300 MHz, DMSO-d6) δ 3.80 (s, 3H, CH3O),
6.98-8.07 (m, 13H), 8.51 (s, 1H, CH), 8.58 (s, 1H, CH) and
11.92 (s, 1H, NH); 13C NMR (75 MHz, DMSO-d6) δ 55.2,
100.9, 114.0, 121.4, 122.1, 126.5, 126.9, 127.8, 129.5, 130.8,
133.2, 138.1, 145.7, 146.8, 147.8, 150.5, 153.7, 160.3, 161.6;
MS (EI, 70 eV) m/z (%): 454 (M+, 41.5), 77 (100) . Anal.
Calcd. for C25H19ClN6O (454.13): C, 66.01; H, 4.21; Cl,
7.79; N, 18.47. Found: C, 65.91; H, 4.25; Cl, 7.74; N, 18.49.
4.5.17 | 4-(2-((1H-Indol-3-yl)methylene)
hydrazinyl)-1-phenyl-3-(p-tolyl)-1H-
pyrazolo[3,4-d]pyrimidine (20H)
Yield (82%); Yellow crystals; mp 238ꢀC-240ꢀC (CH3CN);
1
IR (νmax, cm−1) ν 3340 (NH) cm−1; H NMR (300 MHz,
DMSO-d6) δ 2.39 (s, 3H, CH3), 7.22-8.11 (m, 13H), 8.38 (s,

12
HASSANEEN ET AL.
4.5.21 | 4-(2-(4-Chlorobenzylidene)
hydrazinyl)-3-(4-chlorophenyl)-1-phenyl-
1H-pyrazolo[3,4-d]pyrimidine (21D)
17.8), 320 (100). Anal. Calcd. for C26H18ClN7 (463.13): C,
67.31; H, 3.91; Cl, 7.64; N, 21.13. Found: C, 67.40; H,
3.87; Cl, 7.62; N, 21.10.
Yield (74%); Yellow crystals; mp 226ꢀC-228ꢀC (DMF); MS
(EI, 70 eV) m/z (%): 458 (M+, 36.5), 77 (100). Anal. Calcd.
for C24H16Cl2N6 (458.08): C, 62.76; H, 3.51; Cl, 15.44; N,
18.30. Found: C, 62.68; H, 3.56; Cl, 15.42; N, 18.39.
4.6 | 7-Phenyl-7H-pyrazolo[4,3-e][1,2,4]
triazolo[4,3-c]pyrimidine derivatives (22-24)
To a solution of the appropriate hydrazone 19-21
(1.0 mmol) in ethanol (25 mL), a solution of ferric chlo-
ride (2 M, 2.0 mL) was added, and the mixture was
stirred at room temperature for 12 hours. The reaction
mixture was poured on cold water (50 mL); the solid was
collected, washed with water, and finally crystallized
from the suitable solvent to give 22-24.
4.5.22 | 3-(4-Chlorophenyl)-
4-(2-(4-nitrobenzylidene)hydrazinyl)-
1-phenyl-1H-pyrazolo[3,4-d]
pyrimidine (21E)
Yield (74%); Yellow crystals; mp 270ꢀC-272ꢀC (DMF); MS
(EI, 70 eV) m/z (%): 469 (M+, 47.9), 77 (100). Anal. Calcd.
for C24H16ClN7O2 (469.11): C, 61.35; H, 3.43; Cl, 7.54; N,
20.87. Found: C, 61.19; H, 3.46; Cl, 7.59; N, 20.90.
4.6.1 | 9-(4-Methoxyphenyl)-7-phenyl-
3-(p-tolyl)-7H-pyrazolo[4,3-e][1,2,4]triazolo
[4,3-c]pyrimidine (22B)
1
4.5.23 | 3-(4-Chlorophenyl)-1-phenyl-
4-(2-(pyridin-4-ylmethylene)hydrazinyl)-
1H-pyrazolo[3,4-d]pyrimidine (21F)
Yield (80%); Yellow crystals; mp 210ꢀC-212ꢀC (DMF); H
NMR (300 MHz, DMSO-d6) δ 2.30 (s, 3H, CH3), 3.85 (s,
3H, CH3O), 7.13-8.77 (m, 13H) and 9.25 (s, 1H, CH); 13C
NMR (75 MHz, DMSO-d6) δ 20.99, 55.20, 98.23, 114.10,
122.32, 122.70, 123.54, 127.48, 128.65, 128.81, 129.23,
129.78, 137.96, 138.54, 140.48, 144.76, 145.24, 145.56,
147.08, 160.06; MS (EI, 70 eV) m/z (%): 432 (M+, 100).
Anal. Calcd. for C26H20N6O (432.17): C, 72.21; H, 4.66; N,
19.43. Found: C, 72.06; H, 4.64; N, 19.48.
Yield (74%); Yellow crystals; mp 298ꢀC-300ꢀC; MS (EI,
70 eV) m/z (%): 425 (M+, 50.0), 347 (100). Anal. Calcd.
for C23H16ClN7 (425.12): C, 64.87; H, 3.79; Cl, 8.32; N,
23.02. Found: C, 64.78; H, 3.81; Cl, 8.38; N, 23.00.
4.5.24 | 3-(4-Chlorophenyl)-1-phenyl-
4-(2-(thiophen-2-ylmethylene)hydrazinyl)-
1H-pyrazolo[3,4-d]pyrimidine (21G)
4.6.2 | 9-(4-Methoxyphenyl)-7-phenyl-
3-(pyridin-4-yl)-7H-pyrazolo[4,3-e][1,2,4]
triazolo[4,3-c]pyrimidine (22F)
Yield (76%); Yellow crystals; mp 218ꢀC-220ꢀC (DMF); MS
(EI, 70 eV) m/z (%): 430 (M+, 54.7), 77 (100). Anal. Calcd. for
C22H15ClN6S (430.08): C, 61.32; H, 3.51; Cl, 8.23; N, 19.50; S,
7.44. Found: C, 61.19; H, 3.56; Cl, 8.29; N, 19.49; S, 7.47.
1
Yield (75%); Yellow crystals; mp 252ꢀC-254ꢀC (DMF); H
NMR (300 MHz, DMSO-d6) δ 3.82 (s, 3H, CH3O), 7.02-8.81
(m, 13H) and 9.31(s, 1H, CH); MS (EI, 70 eV) m/z (%):
419 (M+, 100). Anal. Calcd. for C24H17N7O (419.15): C,
68.72; H, 4.09; N, 23.38. Found: C, 68.62; H, 4.14; N, 23.40.
4.5.25 | 4-(2-((1H-Indol-3-yl)methylene)
hydrazinyl)-3-(4-chlorophenyl)-1-phenyl-
1H-pyrazolo[3,4-d]-pyrimidine (21H)
4.6.3 | 7-Phenyl-3,9-di-p-tolyl-7H-
pyrazolo[4,3-e][1,2,4]triazolo[4,3-c]
pyrimidine (23B)
Yield (79%); Yellow crystals; mp 222ꢀC-224ꢀC (DMF); IR
(νmax, cm−1) ν 3329 (NH) cm−1 1H NMR (300 MHz,
;
DMSO-d6) δ 7.21-8.10 (m, 13H), 8.52 (s, 1H, CH), 8.56 (s,
1H, CH), 8.71 (s, 1H, CH-Indol), 11.42 (s, 1H, NH) and
11.64 (s, 1H, NH); 13C NMR (75 MHz, DMSO-d6) δ 101.0,
111.7, 112.5, 120.4, 122.3, 124.5, 127.0, 127.8, 129.0, 130.8,
131.1, 131.5, 133.2, 137.1, 138.1, 144.2, 144.2, 145.6, 148.3,
150.3, 151.8, 158.8; MS (EI, 70 eV) m/z (%): 463 (M+,
Yield (82%); Yellow crystals; mp 208ꢀC-210ꢀC (CH3CN);
1H NMR (300 MHz, DMSO-d6) δ 2.29 (s, 3H, CH3), 2.37
(s, 3H, CH3), 7.25-8.71 (m, 13H) and 9.26 (s, 1H, CH); MS
(EI, 70 eV) m/z (%): 416 (M+, 100). Anal. Calcd. for
C26H20N6 (416.17): C, 74.98; H, 4.84; N, 20.18. Found: C,
74.82; H, 4.86; N, 20.16.

HASSANEEN ET AL.
13
4.6.4 | 3-(4-Chlorophenyl)-7-phenyl-9-(p-
tolyl)-7H-pyrazolo[4,3-e][1,2,4]triazolo[4,3-c]
pyrimidine (23D)
65.17; H, 3.33; Cl, 8.36; N, 23.13. Found: C, 65.02; H,
3.32; Cl, 8.39; N, 23.16.
Yield (79%); Yellow crystals; mp 218ꢀC-220ꢀC (CH3CN);
1H NMR (300 MHz, DMSO-d6) δ 2.50 (s, 3H, CH3),
7.04-8.77 (m, 13H) and 9.31 (s, 1H, CH); Anal. Calcd. for
C25H17ClN6 (436.12): C, 68.73; H, 3.92; Cl, 8.11; N, 19.24.
Found: C, 68.61; H, 3.89; Cl, 8.15; N, 19.27.
4.7 | 7H-Pyrazolo[4,3-e][1,2,4]triazolo
[1,5-c]pyrimidine derivatives (25-27)
Method A: To a solution of the appropriate 22-24
(2.0 mmol) in ethanol (30 mL), sodium acetate (0.16 g,
2.0 mmol) was added, and the mixture was refluxed for
8 hours and then cooled. The precipitated solid was fil-
tered, washed with water, and finally crystallized from
DMF to give the respective product 25-27.
Method B: Refluxing of equal moles of compound 11-
13 (5.0 mmol) and acid chloride (5.0 mmol) in pyridine
(10 mL) for 4 hours, then cooled and poured into cooled
HCl (10%) with stirring. The solid that precipitated was
collected, washed with cold water, and finally crystallized
from DMF to give 25-27.
4.6.5 | 7-Phenyl-3-(pyridin-4-yl)-9-(p-
tolyl)-7H-pyrazolo[4,3-e][1,2,4]triazolo[4,3-c]
pyrimidine (23F)
1
Yield (78%); Yellow crystals; mp 280ꢀC-282ꢀC (DMF); H
NMR (300 MHz, DMSO-d6) δ 2.30 (s, 3H, CH3), 7.24-8.39 (m,
13H) and 9.29(s, 1H, CH); MS (EI, 70 eV) m/z (%): 403 (M+,
48.3), 64 (100). Anal. Calcd. for C24H17N7 (403.15): C,
71.45; H, 4.25; N, 24.30. Found: C, 71.30; H, 4.26; N, 24.33.
4.7.1 | 9-(4-Methoxyphenyl)-
2,7-diphenyl-7H-pyrazolo[4,3-e][1,2,4]
triazolo[1,5-c]pyrimidine (25A)
4.6.6 | 9-(4-Chlorophenyl)-7-phenyl-3-(p-
tolyl)-7H-pyrazolo[4,3-e][1,2,4]triazolo[4,3-c]
pyrimidine (24B)
Yield (81%); Yellow crystals; mp 220ꢀC-222ꢀC; MS (EI,
70 eV) m/z (%): 418 (M+, 100) . Anal. Calcd. for
C25H18N6O (418.15): C, 71.76; H, 4.34; N, 20.08.
Found: C, 71.68; H, 4.28; N, 20.04.
1
Yield (78%); Yellow crystals; mp 232ꢀC-234ꢀC (DMF); H
NMR (300 MHz, DMSO-d6) δ 2.31 (s, 3H, CH3), 7.45-8.85 (m,
13H) and 9.29 (s, 1H, CH); MS (EI, 70 eV) m/z (%): 438 (M+,
100). Anal. Calcd. for C25H17ClN6 (436.12): C, 68.73; H, 3.92;
Cl, 8.11; N, 19.24. Found: C, 68.60; H, 3.91; Cl, 8.16; N, 19.27.
4.7.2 | 9-(4-Methoxyphenyl)-7-phenyl-
2-(p-tolyl)-7H-pyrazolo[4,3-e][1,2,4]triazolo
[1,5-c]pyrimidine (25B)
4.6.7 | 3,9-Bis(4-chlorophenyl)-7-phenyl-
7H-pyrazolo[4,3-e][1,2,4]triazolo[4,3-c]
pyrimidine (24D)
1
Yield (80%); Yellow crystals; mp 260ꢀC-262ꢀC; H NMR
(300 MHz, DMSO-d6) δ 2.50 (s, 3H, CH3), 3.89 (s, 3H,
CH3O), 7.20-8.80 (m, 13H) and 9.72 (s, 1H, CH); MS (EI,
70 eV) m/z (%): 432 (M+, 100). Anal. Calcd. for
C26H20N6O (432.17): C, 72.21; H, 4.66; N, 19.43.
Found: C, 72.09; H, 4.60; N, 19.39.
1
Yield (82%); Yellow crystals; mp 220ꢀC-222ꢀC (DMF); H
NMR (300 MHz, DMSO-d6) δ 7.34-8.51 (m, 13H) and 9.28
(s, 1H, CH); MS (EI, 70 eV) m/z (%): 456 (M+, 52.5),
321 (100). Anal. Calcd. for C24H14Cl2N6 (456.07): C,
63.03; H, 3.09; Cl, 15.50; N, 18.38. Found: C, 62.92; H,
3.12; Cl, 15.54; N, 18.40.
4.7.3 | 2,9-Bis(4-methoxyphenyl)-
7-phenyl-7H-pyrazolo[4,3-e][1,2,4]triazolo
[1,5-c]pyrimidine (25C)
4.6.8 | 9-(4-Chlorophenyl)-7-phenyl-
3-(pyridin-4-yl)-7H-pyrazolo[4,3-e][1,2,4]
triazolo[4,3-c]pyrimidine (24F)
1
Yield (79%); Yellow crystals; mp 250ꢀC-252ꢀC; H NMR
(300 MHz, DMSO-d6) δ 3.87 (s, 3H, CH3O), 3.89 (s, 3H,
CH3O), 7.14-8.80 (m, 13H) and 9.69 (s, 1H, CH); 13C
NMR (75 MHz, DMSO-d6) δ 55.1, 55.5, 103.8, 116.0,
119.8, 123.6, 126.3, 128.9, 129.6, 129.9, 130.5, 131.2, 131.7,
135.3, 140.4, 141.3, 145.8, 149.9, 150.9, 157.8; MS (EI,
1
Yield (77%); Yellow crystals; mp 246ꢀC-248ꢀC (DMF); H
NMR (300 MHz, DMSO-d6) δ 7.34-8.85 (m, 13H) and 9.28
(s, 1H, CH); MS (EI, 70 eV) m/z (%): 423 (M+, 51.4),
64 (100). Anal. Calcd. for C23H14ClN7 (423.10): C,

14
HASSANEEN ET AL.
70 eV) m/z (%): 448 (M+, 100). Anal. Calcd. for
C26H20N6O2 (448.16): C, 69.63; H, 4.50; N, 18.74.
Found: C, 69.54; H, 4.55; N, 18.79.
158.4; MS (EI, 70 eV) m/z (%): 432 (M+, 100). Anal.
Calcd. for C26H20N6O (432.17): C, 72.21; H, 4.66; N,
19.43. Found: C, 72.12; H, 4.60; N, 19.47.
4.7.4 | 2-(4-Chlorophenyl)-
9-(4-methoxyphenyl)-7-phenyl-7H-pyrazolo
[4,3-e][1,2,4]triazolo[1,5-c]-pyrimidine (25D)
4.7.8 | 2-(4-Chlorophenyl)-7-phenyl-9-(p-
tolyl)-7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]
pyrimidine (26D)
1
Yield (80%); Yellow crystals; mp 262ꢀC-264ꢀC; MS (EI,
70 eV) m/z (%): 452 (M+, 100). Anal. Calcd. for
C25H17ClN6O (452.12): C, 66.30; H, 3.78; Cl, 7.83; N,
18.56. Found: C, 66.19; H, 3.71; Cl, 7.79; N, 18.50.
Yield (85%); Yellow crystals; mp 280ꢀC-282ꢀC; H NMR
(300 MHz, DMSO-d6) δ 2.42 (s, 3H, CH3), 7.40-8.66 (m,
13H) and 9.70 (s, 1H, CH); MS (EI, 70 eV) m/z (%):
436 (M+, 100). Anal. Calcd. for C25H17ClN6 (436.12): C,
68.73; H, 3.92; Cl, 8.11; N, 19.24. Found: C, 68.63; H,
3.88; Cl, 8.08; N, 19.19.
4.7.5 | 2,7-Diphenyl-9-(p-tolyl)-7H-
pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]
pyrimidine (26A)
4.7.9 | 9-(4-Chlorophenyl)-2,7-diphenyl-
7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]
pyrimidine (27A)
1
Yield (85%); Yellow crystals; mp 190ꢀC-192ꢀC; H NMR
(300 MHz, DMSO-d6) δ 2.50 (s, 3H, CH3), 7.00-8.91 (m,
14H) and 9.35 (s, 1H, CH); MS (EI, 70 eV) m/z (%):
402 (M+, 100) . Anal. Calcd. for C25H18N6 (402.16): C,
74.61; H, 4.51; N, 20.88. Found: C, 74.52; H,
4.48; N, 20.85.
1
Yield (79%); Yellow crystals; mp 272ꢀC-274ꢀC; H NMR
(300 MHz, DMSO-d6) δ 7.37-8.81 (m, 14H) and 9.31 (s,
1H, CH); MS (EI, 70 eV) m/z (%): 422 (M+, 100). Anal.
Calcd. for C24H15ClN6 (422.10): C, 68.17; H, 3.58; Cl,
8.38; N, 19.87. Found: C, 68.09; H, 3.60; Cl,
8.30; N, 19.85.
4.7.6 | 7-Phenyl-2,9-di-p-tolyl-7H-
pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]
pyrimidine (26B)
4.7.10 | 9-(4-Chlorophenyl)-7-phenyl-
2-(p-tolyl)-7H-pyrazolo[4,3-e][1,2,4]triazolo
[1,5-c]pyrimidine (27B)
1
Yield (83%); Yellow crystals; mp 264ꢀC-266ꢀC; H NMR
(300 MHz, DMSO-d6) δ 2.30 (s, 3H, CH3), 2.33 (s, 3H,
CH3), 7.28-8.54 (m, 13H) and 9.43 (s, 1H, CH); 13C NMR
(75 MHz, DMSO-d6) δ 20.6, 21.5, 104.5, 115.3, 120.8,
124.5, 126.1, 128.5, 129.3, 129.7, 130.1, 130.8, 131.5, 134.6,
140.8, 141.7, 145.0, 149.9, 150.2, 158.3; MS (EI, 70 eV) m/
z (%): 416 (M+, 100). Anal. Calcd. for C26H20N6
(416.17): C, 74.98; H, 4.84; N, 20.18. Found: C, 74.92; H,
4.78; N, 20.10.
1
Yield (85%); Yellow crystals; mp 268ꢀC-270ꢀC; H NMR
(300 MHz, DMSO-d6) δ 2.37 (s, 3H, CH3), 7.43-8.87 (m,
13H) and 9.30 (s, 1H, CH); MS (EI, 70 eV) m/z (%):
436 (M+, 100). Anal. Calcd. for C25H17ClN6 (436.12): C,
68.73; H, 3.92; Cl, 8.11; N, 19.24. Found: C, 68.60; H,
3.95; Cl, 8.05; N, 19.30.
4.7.11 | 9-(4-Chlorophenyl)-
2-(4-methoxyphenyl)-7-phenyl-7H-pyrazolo
[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine (27C)
4.7.7 | 2-(4-Methoxyphenyl)-7-phenyl-
9-(p-tolyl)-7H-pyrazolo[4,3-e][1,2,4]triazolo
[1,5-c]pyrimidine (26C)
1
Yield (84%); Yellow crystals; mp 260ꢀC-262ꢀC; H NMR
Yield (82%); Yellow crystals; mp 255ꢀC-257ꢀC; 1H
NMR (300 MHz, DMSO-d6) δ 2.32 (s, 3H, CH3), 3.82
(s, 3H, CH3O), 7.09-8.64 (m, 13H) and 9.64 (s, 1H,
CH); 13C NMR (75 MHz, DMSO-d6) δ 22.6, 55.4, 103.1,
116.5, 119.4, 123.3, 126.8, 128.4, 129.9, 130.5, 130.9,
131.5, 131.9, 135.1, 140.0, 141.3, 145.6, 149.4, 150.2,
(300 MHz, DMSO-d6) δ 3.80 (s, 3H, CH3O), 7.15-8.58 (m,
13H) and 9.60 (s, 1H, CH); MS (EI, 70 eV) m/z (%):
452 (M+, 100). Anal. Calcd. for C25H17ClN6O (452.12): C,
66.30; H, 3.78; Cl, 7.83; N, 18.56. Found: C, 66.21; H,
3.81; Cl, 7.78; N, 18.52.

HASSANEEN ET AL.
15
4.7.12 | 2,9-Bis(4-chlorophenyl)-7-phenyl-
7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]
pyrimidine (27D)
4.8.3 | 1,3-Diphenyl-4-(2-(1-(pyridin-4-yl)
ethylidene)hydrazinyl)-1H-pyrazolo[3,4-d]
pyrimidine (28C)
Yield (77%); Yellow crystals; mp 288ꢀC-290ꢀC; MS (EI,
70 eV) m/z (%): 456 (M+, 26.7), 64 (100). Anal. Calcd.
for C24H14Cl2N6 (456.07): C, 63.03; H, 3.09; Cl,
15.50; N, 18.38. Found: C, 62.95; H, 3.00; Cl,
15.47; N, 18.30.
Yield (81%); Yellow crystals; mp 266ꢀC-268ꢀC (DMF); IR
(νmax, cm−1) ν 3359 (NH) cm−1; MS (EI, 70 eV) m/z (%):
405 (M+, 57.0), 390 (100). Anal. Calcd. for C24H19N7
(405.17): C, 71.09; H, 4.72; N, 24.18. Found: C, 70.94; H,
4.76; N, 24.11.
4.8 | 1-Phenyl-4-(2-(1-(aryl)ethylidene)
hydrazinyl)-1H-pyrazolo[3,4-d]pyrimidine
derivatives (28-31)
4.8.4 | 1,3-Diphenyl-4-(2-(1-(thiophen-
2-yl)ethylidene)hydrazinyl)-1H-pyrazolo
[3,4-d]pyrimidine (28D)
A mixture of hydrazine 14-17 (5.0 mmol) and the appro-
priate ketone (5.0 mmol) were refluxed in absolute etha-
nol (30 mL) for 6 hours in the presence of few drops of
acetic acid. The reaction mixture was cooled; the precipi-
tate that separated was collected and crystallized from
the suitable solvent to give the corresponding hydrazone
derivatives 28-31.
Yield (82%); Yellow crystals; mp 167ꢀC-168ꢀC (Ethanol);
1
IR (νmax, cm−1) ν 3362 (NH) cm−1; H NMR (300 MHz,
DMSO-d6) δ 2.49 (s, 3H, CH3), 7.12-8.23 (m, 13H), 8.43 (s,
1H, CH), and 11.40 (s, 1H, NH); 13C NMR (75 MHz,
DMSO-d6) δ 15.4, 101.4, 120.6, 121.1, 122.1, 126.3, 127.0,
127.6, 128.3, 129.0, 129.4, 132.5, 138.6, 144.9, 145.5, 147.0,
148.0, 150.4, 154.7; MS (EI, 70 eV) m/z (%): 410 (M+,
59.48), 395 (100). Anal. Calcd. for C23H18N6S (410.13): C,
67.30; H, 4.42; N, 20.47; S, 7.81. Found: C, 67.25; H,
4.46; N, 20.41; S, 7.86.
4.8.1 | 1,3-Diphenyl-4-(2-(1-(pyridin-2-yl)
ethylidene)hydrazinyl)-1H-pyrazolo[3,4-d]
pyrimidine (28A)
4.8.5 | 1,3-Diphenyl-
4-(2-(1-phenylethylidene)hydrazinyl)-1H-
pyrazolo[3,4-d]pyrimidine (28E)
Yield (81%); Yellow crystals; mp 179ꢀC-180ꢀC (EtOH); IR
(νmax, cm−1) ν 3354 (NH) cm−1 1H NMR (300 MHz,
;
DMSO-d6) δ 2.49 (s, 3H, CH3), 7.34-8.10 (m, 14H), 8.60 (s,
1H, CH), and 11.96 (s, 1H, NH); 13C NMR (75 MHz,
DMSO-d6) δ 18.6, 101.5, 121.2, 122.2, 123.8, 126.9, 127.7,
128.6, 129.0, 129.3, 132.0, 135.9, 138.2, 147.1, 147.2, 147.8,
148.5, 150.6, 155.9, 159.8; MS (EI, 70 eV) m/z (%):
405 (M+, 11.97), 327 (100). Anal. Calcd. for C24H19N7
(405.17): C, 71.09; H, 4.72; N, 24.18. Found: C, 71.13; H,
4.69; N, 24.15.
Yield (79%); Yellow crystals; mp 161ꢀC-162ꢀC (Ethanol);
1
IR (νmax, cm−1) ν 3354 (NH) cm−1; H NMR (300 MHz,
DMSO-d6) δ 2.50 (s, 3H, CH3), 7.41-8.12 (m, 15H), 8.47 (s,
1H, CH), and 11.82 (s, 1H, NH); 13C NMR (75 MHz,
DMSO-d6) δ 18.5, 101.4, 120.5, 122.1, 1267, 126.9, 127.6,
128.0, 128.5, 128.9, 129.1, 132.1, 138.2, 138.4, 146.3, 147.1,
147.8, 150.5, 158.5; MS (EI, 70 eV) m/z (%): 404 (M+, 8.05),
59 (100). Anal. Calcd. for C25H20N6 (404.17): C, 74.24; H,
4.98; N, 20.78. Found: C, 74.30; H, 4.95; N, 20.73.
4.8.2 | 1,3-Diphenyl-4-(2-(1-(pyridin-3-yl)
ethylidene)hydrazinyl)-1H-pyrazolo[3,4-d]
pyrimidine (28B)
4.8.6 | 4-(2-(1-(9H-Fluoren-1-yl)
ethylidene)hydrazinyl)-1,3-diphenyl-1H-
pyrazolo[3,4-d]pyrimidine (28F)
Yield (82%); Yellow crystals; mp 234ꢀC-236ꢀC (DMF); IR
(νmax, cm−1) ν 3351 (NH) cm−1 1H NMR (300 MHz,
;
DMSO-d6) δ 2.47 (s, 3H, CH3), 7.30-8.42 (m, 14H), 8.62 (s,
1H, CH), and 11.86 (s, 1H, NH); MS (EI, 70 eV) m/z (%):
405 (M+, 21.84), 77 (100). Anal. Calcd. for C24H19N7
(405.17): C, 71.09; H, 4.72; N, 24.18. Found: C, 70.96; H,
4.61; N, 24.20.
Yield (83%); Yellow crystals; mp 228ꢀC-230ꢀC (Dioxane);
IR (νmax, cm−1) ν 3364 (NH) cm−1; MS (EI, 70 eV) m/z
(%): 492 (M+, 100). Anal. Calcd. for C32H24N6 (492.21): C,
78.03; H, 4.91; N, 17.06. Found: C, 78.11; H,
4.88; N, 17.00.

16
HASSANEEN ET AL.
4.8.7 | 4-(2-(1-(Naphthalen-1-yl)
ethylidene)hydrazinyl)-1,3-diphenyl-1H-
pyrazolo[3,4-d]pyrimidine (28G)
4.8.11 | 3-(4-Methoxyphenyl)-1-phenyl-
4-(2-(1-(thiophen-2-yl)ethyli-dene)
hydrazinyl)-1H-pyrazolo[3,4-d]
pyrimidine (29D)
Yield (85%); Yellow crystals; mp 216ꢀC-218ꢀC (DMF); IR
(νmax, cm−1) ν 3360 (NH) cm−1; MS (EI, 70 eV) m/z (%):
454 (M+, 33.68), 439 (100). Anal. Calcd. for C29H22N6
(454.19): C, 76.63; H, 4.88; N, 18.49. Found: C, 76.69; H,
4.85; N, 18.44.
Yield (83%); Yellow crystals; mp 191ꢀC-192ꢀC
1
(Dioxane); IR (νmax, cm−1) ν 3358 (NH) cm−1; H NMR
(300 MHz, DMSO-d6) δ 2.50 (s, 3H, CH3), 3.82 (s, 3H,
CH3O), 7.00-8.10 (m, 12H), 8.41 (s, 1H, CH), and 11.50
(s, 1H, NH); 13C NMR (75 MHz, DMSO-d6) δ 15.6, 55.2,
101.1, 113.2, 120.8, 122.1, 124.6, 125.6, 126.9, 127.6,
128.4, 130.6, 138.2,144.1, 145.8, 146.9, 147.9,150.3, 154.7,
159.7; MS (EI, 70 eV) m/z (%): 440 (M+, 47.11), 77 (100).
Anal. Calcd. for C24H20N6OS (440.14): C, 65.44; H,
4.58; N, 19.08; S, 7.28. Found: C, 65.39; H, 4.56; N,
19.04; S, 7.24.
4.8.8 | 3-(4-Methoxyphenyl)-1-phenyl-
4-(2-(1-(pyridin-2-yl)ethyl-idene)
hydrazinyl)-1H-pyrazolo[3,4-d]
pyrimidine (29A)
Yield (80%); Yellow crystals; mp 175ꢀC-176ꢀC (CH3CN);
1
IR (νmax, cm−1) ν 3357 (NH) cm−1; H NMR (300 MHz,
DMSO-d6) δ 2.51 (s, 3H, CH3), 3.81 (s, 3H, CH3O),
6.99-8.10 (m, 13H), 8.60 (s, 1H, CH), and 11.92 (s, 1H,
NH); 13C NMR (75 MHz, DMSO-d6) δ 13.5, 55.1, 101.1,
113.1, 120.6, 121.1, 122.0, 123.7, 124.5, 126.8, 128.9, 130.6,
135.9, 138.2, 147.0, 147.1, 147.6, 148.5, 150.5, 155.9, 159.6;
MS (EI, 70 eV) m/z (%): 435 (M+,17.27), 357 (100). Anal.
Calcd. for C25H21N7O (435.18): C, 68.95; H, 4.86; N,
22.51. Found: C, 68.90; H, 4.89; N, 22.49.
4.8.12 | 3-(4-Methoxyphenyl)-1-phenyl-
4-(2-(1-phenylethylidene)-hydrazinyl)-1H-
pyrazolo[3,4-d]pyrimidine (29E)
Yield (84%); Yellow crystals; mp 179ꢀC-180ꢀC (Dioxane);
IR (νmax, cm−1) ν 3340 (NH) cm−1; MS (EI, 70 eV) m/z
(%): 434 (M+, 29.61), 419 (100). Anal. Calcd. for
C26H22N6O (434.19): C, 71.87; H, 5.10; N, 19.34.
Found: C, 71.91; H, 5.13; N, 19.30.
4.8.9 | 3-(4-Methoxyphenyl)-1-phenyl-
4-(2-(1-(pyridin-3-yl)ethyl-idene)
hydrazinyl)-1H-pyrazolo[3,4-d]
pyrimidine (29B)
4.8.13 | 4-(2-(1-(9H-Fluoren-1-yl)
ethylidene)hydrazinyl)-
3-(4-methoxyphenyl)-1-phenyl-1H-pyrazolo-
[3,4-d]pyrimidine (29F)
Yield (84%); Yellow crystals; mp 218ꢀC-220ꢀC (DMF); IR
(νmax, cm−1) ν 3351 (NH) cm−1
;
1H NMR (300 MHz,
Yield (74%); Yellow crystals; mp 191ꢀC-192ꢀC (Dioxane);
IR (νmax, cm−1) ν 3358 (NH) cm−1; MS (EI, 70 eV) m/z
(%): 522 (M+, 24.91), 165 (100). Anal. Calcd. for
C33H26N6O (522.22): C, 75.84; H, 5.01; N, 16.08.
Found: C, 75.90; H, 4.98; N, 16.02.
DMSO-d6) δ 2.50 (s, 3H, CH3), 3.76 (s, 3H, CH3O),
7.20-8.29 (m, 13H), 8.54 (s, 1H, CH), and 11.90 (s, 1H,
NH); MS (EI, 70 eV) m/z (%): 435 (M+, 30.13), 420 (100).
Anal. Calcd. for C25H21N7O (435.18): C, 68.95; H, 4.86; N,
22.51. Found: C, 68.81; H, 4.80; N, 22.55.
4.8.14 | 1-Phenyl-4-(2-(1-(pyridin-2-yl)
ethylidene)hydrazinyl)-3-(p-tolyl)-1H-
pyrazolo[3,4-d]pyrimidine (30A)
4.8.10 | 3-(4-Methoxyphenyl)-1-phenyl-
4-(2-(1-(pyridin-4-yl)ethy-lidene)
hydrazinyl)-1H-pyrazolo[3,4-d]
pyrimidine (29C)
Yield (85%); Yellow crystals; mp 193ꢀC-194ꢀC (EtOH); IR
(νmax, cm−1) ν 3353 (NH) cm−1 1H NMR (300 MHz,
;
Yield (78%); Yellow crystals; mp 248ꢀC-250ꢀC (DMF); IR
(νmax, cm−1) ν 3362 (NH) cm−1; MS (EI, 70 eV) m/z (%):
435 (M+, 61.1), 420 (100). Anal. Calcd. for C25H21N7O
(435.18): C, 68.95; H, 4.86; N, 22.51. Found: C, 68.85; H,
4.84; N, 22.47.
DMSO-d6) δ 2.36 (s, 3H, CH3), 2.52 (s, 3H, CH3),
7.25-8.30 (m, 13H), 8.58 (s, 1H, CH), and 11.96 (s, 1H,
NH); 13C NMR (75 MHz, DMSO-d6) δ 18.5, 20.9, 101.3,
120.4, 121.1, 122.1, 123.7, 126.9, 128.3, 129.0, 129.1, 129.2,
135.8, 137.9, 147.1, 147.7, 148.7, 150.6, 155.7, 159.6, 169.7;
MS (EI, 70 eV) m/z (%): 419 (M+,11.89), 341 (100). Anal.

HASSANEEN ET AL.
17
Calcd. for C25H21N7 (419.19): C, 71.58; H, 5.05; N, 23.37.
Found: C, 71.62; H, 5.00; N, 23.39.
4.8.19 | 4-(2-(1-(9H-Fluoren-1-yl)
ethylidene)hydrazinyl)-1-phenyl-3-(p-
tolyl)-1H-pyrazolo[3,4-d]pyrimidine (30F)
4.8.15 | 1-Phenyl-4-(2-(1-(pyridin-3-yl)
ethylidene)hydrazinyl)-3-(p-tolyl)-1H-
pyrazolo[3,4-d]pyrimidine (30B)
Yield (75%); Yellow crystals; mp 242ꢀC-244ꢀC (DMF); IR
(νmax, cm−1) ν 3329 (NH) cm−1; MS (EI, 70 eV) m/z (%):
506 (M+, 29.80), 165 (100). Anal. Calcd. for C33H26N6
(506.22): C, 78.24; H, 5.17; N, 16.59. Found: C, 78.30; H,
5.15; N, 16.57.
Yield (79%); Yellow crystals; mp 252ꢀC-254ꢀC (DMF);
1
IR (νmax, cm−1) ν 3349 (NH) cm−1; H NMR (300 MHz,
DMSO-d6) δ 2.38 (s, 3H, CH3), 2.48 (s, 3H, CH3),
7.27-8.37 (m, 13H), 8.59 (s, 1H, CH), and 11.97 (s, 1H,
NH); 13C NMR (75 MHz, DMSO-d6) δ 14.4, 20.9, 101.3,
120.8, 122.2, 123.2, 127.0, 128.4, 129.1, 129.3, 133.8,
133.9, 138.1,138.2, 147.1,147.2, 147.9, 148.1, 149.8,
150.6, 156.6; MS (EI, 70 eV) m/z (%): 419 (M+, 22.3),
404 (100). Anal. Calcd. for C25H21N7 (419.19): C,
71.58; H, 5.05; N, 23.37. Found: C, 71.41; H,
5.12; N, 23.30.
4.8.20 | 3-(4-Chlorophenyl)-1-phenyl-
4-(2-(1-(pyridin-2-yl)ethylidene)-
hydrazinyl)-1H-pyrazolo[3,4-d]
pyrimidine (31A)
Yield (83%); Yellow crystals; mp 216ꢀC-218ꢀC (Dioxane);
1
IR (νmax, cm−1) ν 3338 (NH) cm−1; H NMR (300 MHz,
DMSO-d6) δ 2.45 (s, 3H, CH3), 7.32-8.05 (m, 13H), 8.52 (s,
1H, CH), and 11.86 (s, 1H, NH); 13C NMR (75 MHz,
DMSO-d6) δ 13.5, 101.4, 120.7, 121.1, 122.0, 123.6, 126.9,
127.6, 128.8, 130.7, 130.8, 133.2, 135.7, 138.0, 145.8, 147.6,
148.4, 150.6, 155.7, 159.7; MS (EI, 70 eV) m/z (%):
439 (M+,12.59), 361 (100). Anal. Calcd. for C24H18ClN7
(439.13): C, 65.53; H, 4.12; Cl, 8.06; N, 22.29. Found: C,
65.60; H, 4.15; Cl, 8.02; N, 22.25.
4.8.16 | 1-Phenyl-4-(2-(1-(pyridin-4-yl)
ethylidene)hydrazinyl)-3-(p-tolyl)-1H-
pyrazolo[3,4-d]pyrimidine (30C)
Yield (77%); Yellow crystals; mp 236ꢀC-238ꢀC (DMF); IR
(νmax, cm−1) ν 3358 (NH) cm−1; MS (EI, 70 eV) m/z (%):
419 (M+, 52.7), 404 (100). Anal. Calcd. for C25H21N7
(419.19): C, 71.58; H, 5.05; N, 23.37. Found: C, 71.45; H,
5.15; N, 23.42.
4.8.21 | 3-(4-Chlorophenyl)-1-phenyl-
4-(2-(1-(pyridin-3-yl)ethylidene)-
hydrazinyl)-1H-pyrazolo[3,4-d]
pyrimidine (31B)
4.8.17 | 1-Phenyl-4-(2-(1-(thiophen-2-yl)
ethylidene)hydrazinyl)-3-(p-tolyl)-1H-
pyrazolo[3,4-d]pyrimidine (30D)
Yield (80%); Yellow crystals; mp 262ꢀC-264ꢀC (DMF); IR
(νmax, cm−1) ν 3342 (NH) cm−1 1H NMR (300 MHz,
;
DMSO-d6) δ 2.49 (s, 3H, CH3), 7.40-8.49 (m, 13H), 8.60 (s,
1H, CH), and 11.95 (s, 1H, NH); 13C NMR (75 MHz,
DMSO-d6) δ 14.5, 101.4, 122.2, 123.2, 127.1, 127.8, 129.1,
130.9, 131.0,133.4, 133.8, 133.9, 138.1, 145.9, 146.9, 147.9,
148.1, 149.7, 150.7, 156.7; MS (EI, 70 eV) m/z (%):
439 (M+, 21.31), 77 (100). Anal. Calcd. for C24H18ClN7
(439.13): C, 65.53; H, 4.12; Cl, 8.06; N, 22.29. Found: C,
65.40; H, 4.20; Cl, 8.04; N, 22.31.
Yield (84%); Yellow crystals; mp 193ꢀC-194ꢀC (Dioxane);
IR (νmax, cm−1) ν 3335 (NH) cm−1; MS (EI, 70 eV) m/z
(%): 424 (M+, 47.87), 409 (100). Anal. Calcd. for
C24H20N6S (424.15): C, 67.90; H, 4.75; N, 19.80; S, 7.55.
Found: C, 67.94; H, 4.72; N, 19.83; S, 7.50.
4.8.18 | 1-Phenyl-
4-(2-(1-phenylethylidene)hydrazinyl)-3-(p-
tolyl)-1H-pyrazolo[3,4-d]pyrimidine (30E)
4.8.22 | 3-(4-Chlorophenyl)-1-phenyl-
4-(2-(1-(pyridin-4-yl)ethylid-ene)
hydrazinyl)-1H-pyrazolo[3,4-d]
pyrimidine (31C)
Yield (83%); Yellow crystals; mp 189ꢀC-190ꢀC (Dioxane);
IR (νmax, cm−1) ν 3320 (NH) cm−1; MS (EI, 70 eV) m/z
(%): 418 (M+, 27.70), 403 (100). Anal. Calcd. for C26H22N6
(418.19): C, 74.62; H, 5.30; N, 20.08. Found: C, 74.69; H,
5.32; N, 20.02.
Yield (75%); Yellow crystals; mp 256ꢀC-258ꢀC (DMF); IR
(νmax, cm−1) ν 3339 (NH) cm−1; MS (EI, 70 eV) m/z (%):

18
HASSANEEN ET AL.
439 (M+, 53.1), 424 (100). Anal. Calcd. for C24H18ClN7
(439.13): C, 65.53; H, 4.12; Cl, 8.06; N, 22.29. Found: C,
65.48; H, 4.10; Cl, 8.00; N, 22.22.
precipitated was collected and crystallized from DMF to
give 42-44.
4.9.1 | 10-(4-Methoxyphenyl)-3-methyl-
8-phenyl-2-(phenyldiazenyl)-
4.8.23 | 3-(4-Chlorophenyl)-1-phenyl-
4-(2-(1-(thiophen-2-yl)ethy-lidene)
hydrazinyl)-1H-pyrazolo[3,4-d]
pyrimidine (31D)
4,8-dihydropyrazolo[30,40:4,5]pyrimido[1,6-b]
[1,2,4]triazine (42Aa)
Yield (76%); Red crystals; mp 240ꢀC-242ꢀC; 1H NMR
(300 MHz, DMSO-d6) δ 2.13 (s, 3H, CH3), 3.85 (s, 3H,
CH3O), 6.77-8.04 (m, 14H), 8.42 (s, 1H, CH) and 11.40 (s,
1H, NH); 13C NMR (75 MHz, DMSO-d6) δ 14.8, 55.6,
112.3, 113.8, 114.9, 120.4, 122.9, 124.5, 125.6, 128.1, 128.9,
129.5, 134.7, 140.0, 142.6, 144.8, 145.1, 148.9, 150.3, 151.3,
159.6; MS (EI, 70 eV) m/z (%): 474 (M+, 100). Anal.
Calcd. for C27H22N8 (474.19): C, 68.34; H, 4.67; N, 23.61.
Found: C, 68.15; H, 4.69; N, 23.65.
Yield (80%); Yellow crystals; mp 200ꢀC-202ꢀC
(Dioxane); IR (νmax, cm−1) ν 3350 (NH) cm−1; MS (EI,
70 eV) m/z (%): 444 (M+,1.0), 77 (100). Anal. Calcd. for
C23H17ClN6S (444.09): C, 62.09; H, 3.85; Cl, 7.97; N,
18.89; S, 7.21. Found: C, 62.15; H, 3.80; Cl, 7.93; N,
18.87; S, 7.18.
4.8.24 | 3-(4-Chlorophenyl)-1-phenyl-
4-(2-(1-phenylethylidene)-hydrazinyl)-1H-
pyrazolo[3,4-d]pyrimidine (31E)
4.9.2 | 10-(4-Methoxyphenyl)-3-methyl-
8-phenyl-2-(p-tolyldiazenyl)-
Yield (78%); Yellow crystals; mp 200ꢀC-202ꢀC (Dioxane);
IR (νmax, cm−1) ν 3341 (NH) cm−1; MS (EI, 70 eV) m/z
(%): 438 (M+, 37.31), 423 (100). Anal. Calcd. for
C25H19ClN6 (438.14): C, 68.41; H, 4.36; Cl, 8.08; N, 19.15.
Found: C, 68.48; H, 4.32; Cl, 8.03; N, 19.11.
4,8-dihydropyrazolo[30,40:4,5] pyrimido
[1,6-b][1,2,4]triazine (42Ab)
Yield (71%); Red crystals; mp 242ꢀC-244ꢀC; 1H NMR
(300 MHz, DMSO-d6) δ 2.17 (s, 3H, CH3), 2.22 (s, 3H,
4-CH3C6H4), 3.82 (s, 3H, CH3O), 7.15-8.10 (m, 13H), 8.42
(s, 1H, CH) and 11.49 (s, 1H, NH). Anal. Calcd. for
C28H24N8O (488.21): C, 68.84; H, 4.95; N, 22.94.
Found: C, 68.67; H, 4.96; N, 22.98.
4.8.25 | 4-(2-(1-(9H-Fluoren-1-yl)
ethylidene)hydrazinyl)-3-(4-chloro-
phenyl)-1-phenyl-1H-pyrazolo-[3,4-d]
pyrimidine (31F)
4.9.3 | 2-((4-Chlorophenyl)diazenyl)-
10-(4-methoxyphenyl)-3-methyl-8-phenyl-
4,8-dihydropyrazolo [30,40:4,5]pyrimido
[1,6-b][1,2,4]triazine (42Ac)
Yield (76%); Yellow crystals; mp 238ꢀC-240ꢀC (DMF); IR
(νmax, cm−1) ν 3343 (NH) cm−1; MS (EI, 70 eV) m/z (%):
526 (M+, 13.49), 165 (100). Anal. Calcd. for C32H23ClN6
(526.17): C, 72.93; H, 4.40; Cl, 6.73; N, 15.95. Found: C,
72.99; H, 4.38; Cl, 6.70; N, 15.92.
Yield (70%); Red crystals; mp 255ꢀC-257ꢀC; MS (EI,
70 eV) m/z (%): 508 (M+, 100). Anal. Calcd. for
C27H21ClN8O (508.15): C, 63.72; H, 4.16; Cl, 6.97; N,
22.02. Found: C, 63.60; H, 4.19; Cl, 7.00; N, 22.05.
4.9 | 3-Methyl-8-phenyl-
4,8-dihydropyrazolo[30,40: 4,5]pyrimido
[1,6-b][1,2,4]triazine (42-44)
4.9.4 | 10-(4-Methoxyphenyl)-
3,8-diphenyl-2-(phenyldiazenyl)-
4,8-dihydropyrazolo[30,40:4,5]pyrimido[1,6-b]
[1,2,4]triazine (42Ba)
To a mixture of 3-aryl-4-imino-1-phenyl-1,4-dihydro-5H-
pyrazolo[3,4-d]pyrimidin-5-amine
derivatives
11-13
(3.0 mmol) and hydrazonoyl halides 32 (3.0 mmol) in
chloroform (20 mL), triethylamine (0.6 mL, 6.0 mmol)
was added at room temperature. The reaction mixture
was refluxed for 6 hours and then cooled; the excess chlo-
roform was removed under reduced pressure, and the
residue was treated with ethanol (10 mL). The solid that
Yield (73%); Red crystals; mp 230ꢀC-232ꢀC; MS (EI,
70 eV) m/z (%): 536 (M+, 100). Anal. Calcd. for
C32H24N8O (536.21): C, 71.63; H, 4.51; N, 20.88.
Found: C, 71.50; H, 4.53; N, 20.84.

HASSANEEN ET AL.
19
4.9.5 | 10-(4-Methoxyphenyl)-3,8-diphenyl-
2-(p-tolyldiazenyl)-4,8-dihydropyrazolo
(492.16): C, 65.78; H, 4.29; Cl, 7.19; N, 22.73. Found: C,
65.62; H, 4.31; Cl, 7.20; N, 22.75.
[30,40:4,5]pyrimido[1,6-b][1,2,4]triazine (42Bb)
Yield (72%); Red crystals; mp 242ꢀC-244ꢀC; 1H NMR
(300 MHz, DMSO-d6) δ 2.17 (s, 3H, CH3), 3.84 (s, 3H,
CH3O), 6.68-8.02 (m, 18H), 8.49 (s, 1H, CH) and 11.43 (s,
1H, NH); MS (EI, 70 eV) m/z (%): 550 (M+, 100). Anal.
Calcd. for C33H26N8O (550.22): C, 71.98; H, 4.76; N,
20.35. Found: C, 71.81; H, 4.73; N, 20.40.
4.9.9 | 3,8-Diphenyl-2-(phenyldiazenyl)-
10-(p-tolyl)-4,8-dihydropyrazolo[30,40:4,5]
pyrimido[1,6-b][1,2,4]triazine (43Ba)
Yield (74%); Red crystals; mp 236ꢀC-238ꢀC; 1H NMR
(300 MHz, DMSO-d6) δ 2.42 (s, 3H, CH3), 6.73-8.01 (m, 19H),
8.53 (s, 1H, CH) and 11.47 (s, 1H, NH); MS (EI, 70 eV) m/z
(%): 520 (M+, 100). Anal. Calcd. for C32H24N8 (520.21): C,
73.83; H, 4.65; N, 21.52. Found: C, 73.73; H, 4.69; N, 21.57.
4.9.6 | 3-Methyl-8-phenyl-
2-(phenyldiazenyl)-10-(p-tolyl)-
4,8-dihydropyrazolo[30,40:4,5]pyrimido[1,6-b]
[1,2,4]triazine (43Aa)
4.9.10 | 3,8-Diphenyl-10-(p-tolyl)-2-(p-
tolyldiazenyl)-4,8-dihydro-pyrazolo[30,40:4,5]
pyrimido[1,6-b][1,2,4]triazine (43Bb)
1
Yield (71%); Red crystals; mp 222ꢀC-224ꢀC; H NMR
(300 MHz, DMSO-d6) δ 2.17 (s, 3H, CH3), 2.46 (s, 3H,
CH3), 6.76-8.44 (m, 14H), 8.48 (s, 1H, CH) and 11.43 (s,
1H, NH); 13C NMR (75 MHz, DMSO-d6) δ 14.6, 22.3,
109.3, 112.6, 113.4, 119.7, 121.6, 124.1, 125.3, 128.6,
128.7, 129.3, 130.7, 139.8, 142.4, 144.2, 145.3, 148.6,
150.0, 152.3, 159.8; MS (EI, 70 eV) m/z (%): 458 (M+,
92.9), 77 (100). Anal. Calcd. for C27H22N8 (458.20): C,
70.73; H, 4.84; N, 24.44. Found: C, 70.62; H,
4.86; N, 24.49.
Yield (76%); Red crystals; mp 232ꢀC-234ꢀC; Anal. Calcd.
for C33H26N8 (534.23): C, 74.14; H, 4.90; N, 20.96.
Found: C, 74.01; H, 4.92; N, 20.94.
4.9.11 | 3-(Naphthalen-1-yl)-8-phenyl-
2-(phenyldiazenyl)-10-(p-tolyl)-
4,8-dihydropyrazolo[30,40:4,5]pyrimido[1,6-b]
[1,2,4]triazine (43Ca)
4.9.7 | 3-Methyl-8-phenyl-10-(p-tolyl)-
2-(p-tolyldiazenyl)-4,8-dihydropyrazolo
[30,40:4,5]pyrimido[1,6-b][1,2,4]
triazine (43Ab)
Yield (75%); Red crystals; mp 248ꢀC-250ꢀC; MS (EI,
70 eV) m/z (%): 570 (M+, 1.0), 64 (100). Anal. Calcd. for
C36H26N8 (570.23): C, 75.77; H, 4.59; N, 19.64. Found: C,
75.62; H, 4.53; N, 19.68.
Yield (72%); Red crystals; mp 246ꢀC-248ꢀC; 1H NMR
(300 MHz, DMSO-d6) δ 2.15 (s, 3H, CH3), 2.16 (s, 3H,
CH3), 2.23 (s, 3H, CH3), 7.10-8.01 (m, 13H), 8.49 (s, 1H,
CH) and 11.47 (s, 1H, NH); 13C NMR (75 MHz, DMSO-
d6) δ 14.6, 21.2, 21.4, 108.1, 110.4, 112.5, 117.9, 120.1,
123.2, 125.0, 127.8, 128.1, 129.2, 130.1, 138.7, 141.9, 143.0,
145.3, 149.2, 150.3, 152.2, 159.5; MS (EI, 70 eV) m/z (%):
472 (M+, 100). Anal. Calcd. for C28H24N8 (472.21): C,
71.17; H, 5.12; N, 23.71. Found: C, 71.02; H,
5.16; N, 23.78.
4.9.12 | 10-(4-Chlorophenyl)-3-methyl-
8-phenyl-2-(phenyldiazenyl)-
4,8-dihydropyrazolo[30,40:4,5]pyrimido[1,6-b]
[1,2,4]triazine (44Aa)
Yield (70%); Red crystals; mp 254ꢀC-256ꢀC; MS (EI,
70 eV) m/z (%): 478 (M+, 100). Anal. Calcd. for
C26H19ClN8 (478.14): C, 65.20; H, 4.00; Cl, 7.40; N, 23.40.
Found: C, 65.04; H, 3.98; Cl, 7.43; N, 23.45.
4.9.8 | 2-((4-Chlorophenyl)diazenyl)-
3-methyl-8-phenyl-10-(p-tolyl)-
4,8-dihydropyrazolo[30,40:4,5]pyrimido[1,6-b]
[1,2,4]triazine (43Ac)
4.9.13 | 10-(4-Chlorophenyl)-3-methyl-
8-phenyl-2-(p-tolyldiazenyl)-
4,8-dihydropyrazolo[30,40:4,5]pyrimido[1,6-b]
[1,2,4]triazine (44Ab)
Yield (73%); Red crystals; mp 252ꢀC-254ꢀC; MS (EI, 70 eV)
Yield (75%); Red crystals; mp 270ꢀC-272ꢀC; 1H NMR
(300 MHz, DMSO-d6) δ 2.13 (s, 3H, CH3), 2.26 (s, 3H, CH3),
m/z (%): 492 (M+, 100). Anal. Calcd. for C27H21ClN8

20
HASSANEEN ET AL.
7.06-7.94 (m, 13H), 8.45 (s, 1H, CH) and 11.43 (s, 1H,
NH); MS (EI, 70 eV) m/z (%): 492 (M+, 68.13), 77 (100).
Anal. Calcd. for C27H21ClN8 (492.16): C, 65.78; H, 4.29;
Cl, 7.19; N, 22.73. Found: C, 65.65; H, 4.34; Cl,
7.17; N, 22.78.
4.10 | Antimicrobial activity evaluation
Antimicrobial activity of the tested compounds was deter-
mined using a modified Kirby-Bauer disk diffusion
method.[38] Briefly, 100 μL of the test bacteria/fungi were
grown in 10 mL of fresh media until they reached a count of
approximately 108 cells/mL for bacteria or 105 cells/mL for
fungi.[39] One hundred microliters of microbial suspension
was spread onto agar plates corresponding to the broth in
which they were maintained.
Of the many media available, NCCLS recommends
Mueller-Hinton agar because it results in good batch-to-batch
reproducibility. Disk diffusion method for filamentous fungi
was tested by using approved standard method (M38-A)
developed by the (NCCLS, 2002)[40] for evaluating the suscep-
tibilities of filamentous fungi to antifungal agents. Disk diffu-
sion method for yeasts was developed by using approved
standard method (M44-P) by the (NCCLS, 2009).[41]
4.9.14 | 10-(4-Chlorophenyl)-
2-((4-chlorophenyl)diazenyl)-3-methyl-
8-phenyl-4,8-dihydropyrazolo[30,40:4,5]
pyrimido[1,6-b][1,2,4]triazine (44Ac)
Yield (72%); Red crystals; mp 272ꢀC-274ꢀC; MS (EI,
70 eV) m/z (%): 512 (M+, 7.3), 64 (100). Anal. Calcd. for
C26H18Cl2N8 (512.10): C, 60.83; H, 3.53; Cl, 13.81; N,
21.83. Found: C, 60.70; H, 3.56; Cl, 13.89; N, 21.84.
4.9.15 | 10-(4-Chlorophenyl)-
3,8-diphenyl-2-(phenyldiazenyl)-
4,8-dihydropyrazolo[30,40:4,5]pyrimido
[1,6-b][1,2,4]triazine (44Ba)
4.11 | MIC evaluation
The MIC values were measured by the broth dilution
method.[35,42] Five hundred microliters of a stock solution
(10.24 mg/mL) of each tested compound in DMSO was pre-
pared and then diluted with Mueller-Hinton broth to 1024
μg/mL. The strains were grown briefly at 37ꢀC in Mueller-
Hinton media. After 5 hours of bacterial growth, the bacterial
culture was diluted to obtain a concentration of 5 × 105 cells/
mL. Then, 150-μL bacterial suspensions were added to each
well of the flat-bottomed 96-well tissue culture plate. Twofold
serial dilutions were carried out from the fist well to the tenth
well; the final concentrations of the compounds ranged from
1 to 512 μg/mL, and excess media (150 μL) were discarded
from the last well. The plates were incubated at 37ꢀC for
24 hours in an electro-heating standing temperature cultiva-
tor and were read visually. The MIC of the sample showing
no turbidity was recorded as the lowest concentration of
compound that inhibited bacterial growth completely. Each
assay was run in triplicate.
1
Yield (73%); Red crystals; mp 252ꢀC-254ꢀC; H NMR
(300 MHz, DMSO-d6) δ 6.82-8.16 (m, 19H), 8.56 (s, 1H,
CH) and 11.50 (s, 1H, NH); MS (EI, 70 eV) m/z (%):
540 (M+, 100). Anal. Calcd. for C31H21ClN8 (540.16): C,
68.82; H, 3.91; Cl, 6.55; N, 20.71. Found: C, 68.71; H,
3.89; N, 20.76.
4.9.16 | 10-(4-Chlorophenyl)-
3,8-diphenyl-2-(p-tolyldiazenyl)-
4,8-dihydropyrazolo[30,40:4,5]pyrimido[1,6-b]
[1,2,4]triazine (44Bb)
Yield (71%); Red crystals; mp 242ꢀC-244ꢀC; MS (EI,
70 eV) m/z (%): 554 (M+, 100). Anal. Calcd. for
C32H23ClN8 (554.17): C, 69.25; H, 4.18; Cl, 6.39; N, 20.19.
Found: C, 69.10; H, 4.23; Cl, 6.40; N, 20.16.
ORCID
Hamdi M. Hassaneen https://orcid.org/0000-0003-
0963-4192
4.9.17 | 10-(4-Chlorophenyl)-
3-(naphthalen-1-yl)-8-phenyl-
2-(phenyldiazenyl)-4,8-dihydropyrazolo
[30,40:4,5]pyrimido[1,6-b][1,2,4]
triazine (44Ca)
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https://doi.org/10.1039/p29760000921
How to cite this article: Hassaneen HM, Saleh FM,
Abdallah TA, Mohamed YS, Awad EM. Synthesis,
reactions, and antimicrobial activity of some novel
pyrazolo[3,4-d]pyrimidine, pyrazolo[4,3-e][1,2,4]
triazolo[1,5-c]pyrimidine, and pyrazolo[4,3-e][1,2,4]
triazolo[3,4-c]pyrimidine derivatives. J Heterocyclic
Chem. 2019;1–21. https://doi.org/10.1002/jhet.3835
[26] Shawali, A. S., A. A. Fahmi, H. A. Albar, H. M. Hassaneen,
and H. A. A. J. Chem. Res.(S), 1994, 6, 1040–1049.