Synthesis of new pyrrolo[2,3-d]pyrimidine derivatives as antibacterial and antifungal agents

Article abstract of DOI:10.1016/j.ejmech.2010.08.043

A series of new pyrrole derivatives, pyrrolo[2,3-d]pyrimidine derivatives, pyrrolotriazolopyrimidines and pyrrolotetrazolopyrimidines were synthesized. The evaluation of their antimicrobial activities against Staphylococcus aureus, Escherichia coli, and Candida albicans were carried out. Pyrrolo[2,3-d] pyrimidines 3a-d, 7a,e, 11d exhibited excellent activity against C. albicans with MIC 0.31-0.62 mg/mL. These compounds displayed better antifungal activity than that of standard drug (fluconazole with MIC 1.5 mg/mL). Furthermore, pyrrolo[2,3-d]pyrimidines 3b,c, 7e exhibited the best activity against S. aureus with MIC 0.31 mg/mL, compared with the standard drug (ampicillin with MIC 0.62 mg/mL). The rest of the compounds were found to be inactive against bacteria and fungi.

Full text of DOI:10.1016/j.ejmech.2010.08.043

European Journal of Medicinal Chemistry 45 (2010) 5243e5250
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Synthesis of new pyrrolo[2,3-d]pyrimidine derivatives as antibacterial and
antifungal agents
,
b
a
Khalid Mohammed Hassan Hilmy a , Maha M.A. Khalifa , Mohammed Abd Allah Hawata ,
*
Reda Mohammed AboAlzeen Keshk a, Abd Almeneam El-Torgman a
a Department of Chemistry, Faculty of Science, Menufiya University, Shebin El-Kom, Egypt
b Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt
a r t i c l e i n f o
a b s t r a c t
Article history:
A series of new pyrrole derivatives, pyrrolo[2,3-d]pyrimidine derivatives, pyrrolotriazolopyrimidines and
pyrrolotetrazolopyrimidines were synthesized. The evaluation of their antimicrobial activities against
Staphylococcus aureus, Escherichia coli, and Candida albicans were carried out. Pyrrolo[2,3-d]pyrimidines
3aed, 7a,e, 11d exhibited excellent activity against C. albicans with MIC 0.31e0.62 mg/mL. These
compounds displayed better antifungal activity than that of standard drug (fluconazole with MIC 1.5 mg/
mL). Furthermore, pyrrolo[2,3-d]pyrimidines 3b,c, 7e exhibited the best activity against S. aureus with
MIC 0.31 mg/mL, compared with the standard drug (ampicillin with MIC 0.62 mg/mL). The rest of the
compounds were found to be inactive against bacteria and fungi.
Received 20 April 2010
Received in revised form
12 August 2010
Accepted 17 August 2010
Available online 24 August 2010
Keywords:
Pyrrole derivatives
pyrrolo[2,3-d]pyrimidines
Pyrrolotriazolopyrimidines,
pyrrolotetrazolopyrimidines
Synthesis
Ó 2010 Elsevier Masson SAS. All rights reserved.
Docking studies
MIC
Antimicrobial
1. Introduction
we report the synthesis and antimicrobial activity of a novel series
of pyrroles and pyrrolo[2,3-d]pyrimidine derivatives.
Pyrrolo[2,3-d]pyrimidine derivatives attracted organic chemists
very much due to their biological and chemotherapeutic impor-
tance. Their related fused heterocycles are of interest as potential
bioactive molecules. They are known to exhibit biological activities
such as enzyme inhibitors [1], cytotoxic [2], antiviral [3e5], anti-
inflammatory [6], antialgeric [7], anti-ocular hypertension [8],
antitumor [9e12], antibacterial and antifungal agents [13].
As pathogenic bacteria continuously evolve mechanisms of
resistance to currently used antibacterials, so the discovery of novel
and potent antibacterial drugs is the best way to overcome bacterial
resistance and develop effective therapies [14]. On the meanwhile
Candida infections have increased dramatically over the past three
decades. Candida species is the fourth common cause of nosocomial
bloodstream infections in many hospitals and represents 10% of all
bloodstream infections [15,16]. On the basis of these observations,
2. Results and discussion
2.1. Chemistry
Synthesis of compounds 4aee was achieved through two
synthetic pathways, the first of which was the reaction of 1aee [17]
with triethylorthoformate under reflux for 4 h to give N-[5-(4-
substituted
phenyl)-3-cyano-1-phenyl-1H-pyrrolo-2-yl]-for-
mimidic ethyl ester 2aee. IR spectrum of 2d showed absorption
band at 2217 cmꢀ1 assigned to cyano group (CN). Furthermore, its
1H NMR spectrum showed a singlet at
d
8.40 ppm indicated the
formation of imine (N]CH) and a triplet at 1.09e1.20 ppm (CH3)
and a quartet at 4.00e4.20 ppm (OCH2) confirmed the structure.
d
d
Mass spectrum of 2d showed molecular ion peak at m/z 329 cor-
responding to its molecular formula C21H19N3O. Reaction of the
latter compounds with hydrazine hydrate (99%) in ethanol afforded
3aee. The IR spectrum of 3d revealed the absence of the cyano
group and the appearance of absorption bands at 3422e3200 cmꢀ1
for (NH, NH2). Its 1H NMR spectrum also showed two singlets at
* Corresponding author. P.O. Box 73, Shoubra Misr, Cairo, Egypt. Tel.:
þ2024701517.
E-mail addresses: kmhh20032000@yahoo.com, khaledhilmy@hotmial.com (K.
M. Hassan Hilmy).
0223-5234/$ e see front matter Ó 2010 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2010.08.043

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K.M. Hassan Hilmy et al. / European Journal of Medicinal Chemistry 45 (2010) 5243e5250
d
5.68 & 8.40 ppm which indicated the presence of NH2 & NH
were readily obtained through smooth cyclization of 7aee under
reflux with formic acid (85%) (Scheme 1). Furthermore, reaction of
the latter compounds with aqueous solution of sodium nitrite in
acetic acid at 0e5 ꢁC afforded 8-aryl-7-phenyl-7H-pyrrolo[3,2-e]
tetrazolo[1,5-c]pyrimidine derivatives 8aee. Absence of absorption
bands in the latter series at 3400e3200 cmꢀ1 in the IR spectra as
well as in the 1H NMR spectra was characteristic for the pyrrolo-
tetrazolpyrimidines. On the other hand, compounds 1a,c,d were
reacted with formamide under reflux to give 4-amino-6-aryl-7-
phenyl-7H-pyrrolo[2,3-d]pyrimidine derivatives 9a,c,d, from which
9c exhibited absorption bands ranging from 3400, 3306, 3200,
groups respectively. Cyclization with formic acid (85%) occurred
smoothly by heating under reflux for 8 h to afford our targets 4aee
(Scheme 1). Disappearance of absorption bands at 3400e3200 in
the IR spectra as well as in the 1H NMR spectra was the charac-
teristic for the pyrrolotriazolopyrimidines. The second pathway
involves the conversion of 1aee to 6-aryl-7-phenyl-3,7-dihydro-
pyrrolo[2,3-d]pyrimidin-4-one derivatives 5aee through its
cyclization with formic acid (85%) for 4 h. Chlorination of 5aee with
phosphorus oxychloride under reflux for 10 h afforded 6aee.
Nucleophilic displacement of the 4-chloro group in 6aee was
achieved by heating under reflux with hydrazine hydrate (99%) to
give compounds 7aee. IR spectrum of the titled compound 7e
showed the appearance of absorption bands at 3424, 3349, 3313,
3196 cmꢀ1 for (NH, NH2) respectively, its 1H NMR spectrum showed
3150 cmꢀ1 for the amino (NH2). A singlet at
d 6.85 ppm assigned to
NH2 in the 1H NMR spectrum and molecular ion peak at m/z 320
and Mþ2 at 322 confirmed its molecular formula C18H13ClN4.
Schiff’s bases 10a,c,d were obtained by the reaction of 9a,c,d with
acetaldehyde in ethanol under reflux for 4 h. Moreover, reaction of
1a,c,d with urea/acetamide in the presence of acetic acid, hydro-
chloric acid (3:1) under reflux for 4 h afforded 11a,c,d, and 12a,c,d
respectively (Scheme 2). Compounds 11a and 12d were character-
ized with absorption bands ranging from 3100 to 3345 cmꢀ1 for the
the presence of characteristic peaks at
d 4.02, 8.89 ppm of NH2 and
NH groups, the mass spectrum showed molecular ion peak at m/z
319 corresponding to its molecular formula C18H14FN5 which
confirmed its chemical structure (Scheme 1). 8-Aryl-7-phenyl-7H-
pyrrolo[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine derivatives 4aee
Scheme 1. Compounds: 1a, R ¼ H; 1b, R ¼ Br; 1c, R ¼Cl; 1d, R ¼CH3; 1e, R ¼ F. Reagents and conditions: (a) triethylorthoformate, reflux, 4 h; (b) hydrazine hydrate (99%), ethanol, reflux,
2 h; (c) formic acid (85%), reflux, 4 h; (d) POCl3, reflux, 10 h; (e) hydrazine hydrate (99%), ethanol, reflux, 2 h; (f) formic acid (85%), reflux, 7e8 h; (g) NaNO2, glacial acetic acid, 0e5 ꢁC.

K.M. Hassan Hilmy et al. / European Journal of Medicinal Chemistry 45 (2010) 5243e5250
5245
Scheme 2. Compounds: 1a, R ¼ H; 1c, R ¼ Cl; 1d, R ¼ CH3. Reagents and conditions: (a) formamide, reflux, 4 h; (b) acetaldehyde, reflux, 4 h; (c) urea, glacial acetic acid and conc.
HCl (3:1), reflux, 4 h; (d) acetamide, glacial acetic acid and conc. HCl (3:1), reflux, 4 h.
amino group (NH2) respectively. The presence of 1H NMR charac-
teristic singlet at 6.70 ppm for 2-NH2 group in compound 11a,
however, two singlets at 2.30 and 2.50 ppm corresponding to 2
methyl groups, another singlet at 6.79 ppm (NH2) confirmed the
structure of 12d. All structures were assigned by their mass spec-
trum and elemental analysis.
3. Conclusion
d
In this work, we have synthesized a series of new pyrrole
derivatives 2aee, pyrrolo[2,3-d]pyrimidine derivatives 3aee, 5aee,
6aee, 7aee, 9a,c,de12a,c,d, pyrrolotriazolopyrimidines 4aee and
pyrrolotetrazolopyrimidines 8aee which were screened for their
antimicrobial activities. The tested compounds 3aed, 7a,b,c,e, 9d,
10a, 11a,c,d, 12a demonstrated potent antifungal activity against C.
albicans than that of the standard drug. Also, compounds 3b,c,d,
7a,b,e, 11a,d, and 12c showed antibacterial activity against Gram
positive S. aureus. Moreover, 3b,c and 7e, exhibited antibacterial
activity against gram negative E. coli similar to the standard drug.
It seems obvious that pyrrolo[2,3-d]pyrimidine derivatives in
which the pyrimidine ring is bearing an amino & imino groups
of compounds 3aed, as well as carrying hydrazino group of
compounds 7a,b,c,e and diamino group as in 11a,c,d obtained the
best results in the biological screening. However, fused systems
such as pyrrolotriazolopyrimidines, pyrrolotetrazolopyrimidines as
well as pyrrole derivatives didn’t have such an influence on activity.
d
2.2. Antimicrobial activity
The antimicrobial screenings of the synthesized compounds
were undertaken using agar well diffusion assay [18]. Table 1 lists
the screening results of the tested compounds against the gram
negative bacteria (Escherichia coli), gram positive bacteria (Staph-
ylococcus aureus) in addition to the pathogenic fungi, Candida
albicans. The obtained data revealed that most of the compounds
showed moderate to excellent activities against the microorgan-
isms used at a dose of 5 mg/mL. Compounds showing inhibition of
at least 18 mm were considered active and were further evaluated
for their minimal inhibitory concentration (MIC). Ampicillin and
Tetracycline were used as a standard antibacterial, while Flucona-
zole and Nystatin were used as standard antifungal. DMSO was
used as a blank exhibited no activity against any of the used
organisms. It is well noticed that compounds 3c, 7e showed
remarkable broad spectrum potency against E. coli, S. aureus with
MIC values of 1.25, 0.31 mg/mL respectively, compared with MIC of
Ampicillin 1.25 and 0.62 mg/mL and five times as potent as Flu-
conazole with MIC value of 0.31 mg/mL relative to 1.5 mg/mL of the
latter standard. Compounds 3d, 7a,b, 11a and 12c with
MIC ¼ 0.62 mg/mL were equipotent against S. aureus similar to the
reference standard. However, 3a,b,d and 11d were twice as potent
as Fluconazole against C. albicans with MIC ¼ 0.62 mg/mL Table 2.
4. Experimental protocols
4.1. Chemistry
Melting points were determined on a Stuart melting point
apparatus and are uncorrected. IR spectra (KBr) were measured on
Jasco FT/IR 460 plus (Japan), 1H NMR and 13C NMR spectra were
recorded on Varian Gemini 200 MHz in DMSO-d6 or CDCl3 as
solvent, using tetramethyl-silane (TMS) as internal reference
standard. The chemical shifts values are expressed in ppm.
Elemental analysis (C, H, N) was performed by a Vario III CHN
analyzer (Germany). All compounds were within ꢂ0.4% of the

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K.M. Hassan Hilmy et al. / European Journal of Medicinal Chemistry 45 (2010) 5243e5250
Table 1
theoretical values. Mass spectra were run on DI analysis Shimadzu
QP-2010 plus mass spectrometer. All spectroscopic analysis were
made at the Microanalytical Unit of Cairo University. The progress
of the reaction and the purity of the compounds were monitored by
TLC analytical silica gel plates 60 F254 eluting with CH2Cl2/CH3OH
(39:1). The chemical reagents used in synthesis were purchased
from Fluka, Sigma, and Aldrich.
Inhibition zones (IZ) in mm of the synthesized compounds at 5 mg/mL.
Compound
(mg/mL)
Escherichia coli
Staphylococcus
aureus
Candida albicans
2a
2b
2c
2d
2e
3a
3b
3c
3d
3e
4a
4b
4c
4d
4e
6a
6b
6c
6d
6e
7a
7b
7c
7d
7e
8a
8b
8c
8e
9a
9c
9d
17
e
16
e
19
11
11
e
e
e
11
13
16
27
22
20
15
16
14
18
e
e
13
21
25
21
21
17
13
19
17.5
e
16
23
27
27
21
15
17
19
18
11
17
16.5
17
12
16
15
31
23
19
17
32
17
17
17
11
20
16
25
21
17
15
24
23
23
21
24
16
e
4.1.1. General procedure for the synthesis of compounds (2aee)
A mixture of 1aee [17] (0.01 mol) in triethylorthoformate
(10 mL) was refluxed for 4 h and then excess of ethanol was added.
The solution thus obtained was treated with ice cold water. The
separated solid was filtered and recrystallized from ethanol.
4.1.1.1. N-(3-Cyano-1,5-diphenyl-1H-pyrrol-2-yl)-formimidic
aꢀci1d
ethyl ester (2a). (2.91 g, 92%); mp: 103e104 ꢁC; IR (KBr) cm
:
16
14
17
13
13
13
18
15
16
13
20
16
15
15
e
17
13
16
12
12
15
27
25
17
14
31
16
16
14
e
3134 (CeH aromatic), 2980 (CeH aliphatic), 2217 (C^N),1622,1498
(C]C, C]N); 1H NMR (DMSO-d6)
d
ppm: 1.10e1.20 (t, 3H,
OCH2CH3), 4.00e4.10 (q, 2H, OCH2CH3), 6.71 (s, 1H, CH pyrrole),
7.00e7.50 (m, 10H, ArH), 8.40 (s, 1H, N]CHOEt); 13C NMR: 14.12
(CH3), 63.63 (CH2), 79.81 (CN), 109.75, 117.44, 127.58, 128.16, 128.74,
128.84, 129.33, 131.47, 131.94, 136.59, 146.33, 160.21 (12 type of Ca),
220.04 (N]CHOEt). MS (m/z, %): 315.05 (Mþ, 100). Anal. Calcd for
C20H17N3O (315.37): C, 76.17; H, 5.43; N, 13.32. Found: C, 75.94; H,
5.22; N, 12.96.
4.1.1.2. N-[5-(4-Bromo-phenyl)-3-cyano-1-phenyl-1H-pyrrol-2-yl]-
formimidic ethyl ester (2b). (3.78 g, 96%); mp: 142e143 ꢁC, IR (KBr)
cmꢀ1: 3067 (CeH aromatic), 2984 (CeH aliphatic), 2211 (C^N),
14
16
14
16
16
17
13
14
19
18
14
14
9
15
17
23
21
17
16
24
24
25
20
25
17
9
1630, 1497 (C]C, C]N), 576 (CeBr); 1H NMR (DMSO-d6)
d ppm:
1.10e1.20 (t, 3H, OCH2CH3), 4.00e4.20 (q, 2H, OCH2CH3), 6.80 (s,1H,
CH pyrrole), 7.00e7.50 (m, 9H, ArH), 8.40 (s, 1H, N]CHOEt). MS
(m/z, %): 392.90 (Mþ, 100), 394.90 (Mþ2, 92.06). Anal. Calcd for
C20H16BrN3O (394.26): C, 60.93; H, 4.09; N, 10.66. Found: C, 60.63;
H, 4.19; N, 10.35.
10a
10c
10d
11a
11c
11d
12a
12c
4.1.1.3. N-[5-(4-Chloro-phenyl)-3-cyano-1-phenyl-1H-pyrrol-2-yl]-
formimidic ethyl ester (2c). (2.83 g, 84%); mp: 144e145 ꢁC; IR (KBr)
cmꢀ1: 3068 (CeH aromatic), 2984 (CeH aliphatic), 2211 (C^N),
12d
Ampicillin
Tetracycline
Nystatin
Fluconazole
18
e
20
e
e
1630,1497 (C]C, C]N), 755 (CeCl); 1H NMR (DMSO-d6)
d ppm:
17
26
1.10e1.20 (t, 3H, OCH2CH3), 4.00e4.20 (q, 2H, OCH2CH3), 6.80 (s,1H,
CH pyrrole), 7.00e7.50 (m, 9H, ArH), 8.40 (s, 1H, N]CHOEt). MS
(m/z, %): 349.00 (Mþ, 84.89), 351.00 (Mþ2, 30.74). Anal. Calcd for
C20H16 Cl N3O (349.81): C, 68.67; H, 4.61; N, 12.01. Found: C, 68.99;
H, 4.59; N, 11.66.
e
e, no inhibition zone.
Table 2
The MIC of the compounds tested against organisms.
4.1.1.4. N-(3-Cyano-1-phenyl-5-p-tolyl-1H-pyrrol-2-yl)-formimidic
acid ethyl ester (2d). (3.15 g, 96%); mp: 124e125 ꢁC; IR (KBr)
cmꢀ1: 3134 (CeH aromatic), 2980 (CeH aliphatic), 2217 (C^N),
Compound
(mg/mL)
Escherichia coli
Staphylococcus aureus
Candida albicans
MIC (mg/mL)
MIC (mg/mL)
MIC (mg/mL)
1622, 1498 (C]C, C]N); 1H NMR (DMSO-d6)
d ppm: 1.09e1.16 (t,
2a
3a
3b
3c
3d
7a
7b
7c
7e
9a
9d
10a
11a
11c
11d
12a
e
e
2.5
e
1.25
0.31
0.31
0.62
0.62
0.62
e
0.62
0.62
0.31
0.62
0.31
1.25
1.25
0.31
2.5
1.25
1.25
1.25
1.25
0.62
1.25
2.5
3H, OCH2CH3), 2.20 (s, 3H, CH3), 4.01e4.20 (q, 2H, OCH2CH3), 6.60
(s, 1H, CH pyrrole), 6.91e7.60 (m, 9H, ArH), 8.37 (s, 1H, N]
CHOEt). MS (m/z, %): 329.00 (Mþ, 100). Anal. Calcd for C21H19N3O
(329.15): C, 76.57; H, 5.81; N, 12.76. Found: C, 76.50; H, 5.71; N,
12.85.
1.25
1.25
2.5
2.5
e
e
1.25
e
0.31
e
4.1.1.5. N-[3-Cyano-5-(4-fluoro-phenyl)-1-phenyl-1H-pyrrol-2-yl]-
formimidic acid ethyl ester (2e). (2.76 g, 83%); mp: 109e110 ꢁC; IR
(KBr) cmꢀ1: 3120 (CeH aromatic), 2981 (CeH aliphatic), 2211
(C^N), 1630, 1509 (C]C, C]N), 1226 (CeF); 1H NMR (DMSO-d6)
e
2.5
e
1.25
0.62
1.25
0.62
1.25
0.62
0.62
e
e
e
d
ppm: 1.10e1.20 (t, 3H, OCH2CH3), 4.00e4.20 (q, 2H, OCH2CH3),
2.5
2.5
e
6.80 (s, 1H, CH pyrrole), 7.00e7.50 (m, 9H, ArH), 8.40 (s, 1H, N]
CHOEt). MS (m/z, %): 333.13 (Mþ, 100). Anal. Calcd for C20H16FN3O
(333.36): C, 72.06; H, 4.84; N, 12.61; Found: C, 72.20; H, 4.51; N,
12.81.
12c
Ampicillin
Fluconazole
1.25
e
e
1.5

K.M. Hassan Hilmy et al. / European Journal of Medicinal Chemistry 45 (2010) 5243e5250
5247
4.1.2. General procedure for the synthesis of compounds (3aee)
A mixture of 2aee (0.01 mol) and hydrazine hydrate (99%)
(10 mL) was refluxed in ethanol for 2 h. The reaction mixture was
allowed to cool, poured onto crushed ice and neutralized with
(50%) acetic acid. The solid obtained was filtered, washed with
water, dried and recrystallized from dioxane.
4.1.3.1. 7,8-Diphenyl-7H-pyrrolo[3,2-e][1,2,4]triazolo[1,5-c]pyrimi-
dine (4a). 2.86 g, 92% (Method A), 2.55 g, 82% (Method B); mp:
177e178 ꢁC; IR (KBr) cmꢀ1: 3073 (CeH aromatic), 1636, 1500 (C]C,
C]N); 1H NMR (DMSO-d6)
pyrrole), 8.60 (s, 1H, H at C5), 9.49 (s, 1H, H at C2). MS (m/z, %): 311.12
(Mþ, 100). Anal. Calcd for C19H13 N5 (311.34): C, 73.30; H, 4.21; N,
22.49. Found: C, 73.54; H, 4.32; N, 22.89.
d
ppm: 7.13e7.62 (m, 11H, ArH þ CH
4.1.2.1. 3-Amino-4-imino-6,7-diphenyl-7H-pyrrolo[2,3-d]pyrimidine
(3a). (2.67 g, 89%); mp: 122e123 ꢁC; IR (KBr) cmꢀ1: 3400, 3312,
3200 and 3150 (NH, NH2), 1639 (C]N imine), 1593, 1497 (C]C, C]
4.1.3.2. 7-Phenyl-8-(4-bromophenyl)-7H-pyrrolo[3,2-e][1,2,4]tri-
azolo[1,5-c]pyrimidine (4b). 3.46 g, 89% (Method A), 3.77 g, 97%
(Method B); mp: 217e218 ꢁC; IR (KBr) cmꢀ1: 3061 (CeH aromatic),
1644, 1499 (C]C, C]N), 555 (CeBr); 1H NMR (DMSO-d6)
N); 1H NMR (DMSO-d6)
d ppm: 5.60 (s, 2H, NH2), 6.90 (s, 1H, CH
pyrrole), 7.10e7.60 (m, 10H, ArH), 7.90 (s, 1H, H at C2), 8.10 (s, 1H,
NH). MS (m/z, %): 301.00 (Mþ, 100). Anal. Calcd for C18H15N5
(301.35): C, 71.74; H, 5.02; N, 23.24. Found: C, 71.58; H, 4.87; N,
23.57.
d
ppm: 7.10e7.70 (m, 10H, ArH þ CH pyrrole), 8.60 (s, 1H, H at C5),
9.50 (s, 1H, H at C2). MS (m/z, %): 389.03 (Mþ, 100), 391.03 (Mþ2
,
98.00). Anal. Calcd for C19H12 Br N5 (389.03): C, 58.48; H, 3.10; N,
17.95. Found: C, 58.37; H, 3.05; N, 17.71.
4.1.2.2. 3-Amino-4-imino-6-(4-bromophenyl)-7-phenyl-7H-pyrrolo
[2,3-d]pyrimidine (3b). (3.19 g, 84%); mp: 223e224 ꢁC; IR (KBr)
cmꢀ1: 3400, 3312, 3200 and 3150 (NH, NH2), 1639 (C]N imine),
4.1.3.3. 7-Phenyl-8-(4-chlorophenyl)-7H-pyrrolo[3,2-e][1,2,4]triazolo
[1,5-c] pyrimidine (4c). 3.20 g, 93% (Method A), 2.52 g, 73% (Method
B); mp: 225e227 ꢁC; IR (KBr) cmꢀ1: 3061 (CeH aromatic), 1644,
1501 (C]C, C]N), 756 (CeCl); 1H NMR (DMSO-d6)
1593, 1497 (C]C, C]N), 565 (CeBr); 1H NMR (DMSO-d6)
d ppm:
5.70 (s, 2H, NH2), 7.00 (s,1H, CH pyrrole), 7.10e7.60 (m, 9H, ArH),
7.89(s,1H, H at C2), 8.13 (s,1H, NH); 13C NMR: 103.68,106.34,127.85,
128.20, 128.40, 128.98, 129.44, 130.51, 131.81, 133.16, 135.92, 144.29,
147.03, 153.34 (14 type of Ca). MS (m/z, %): 379.o4 (Mþ, 100), 381.04
(Mþ2, 97.00). Anal. Calcd for C18H14 Br N5 (380.24): C, 56.86; H, 3.71;
N, 18.42. Found: C, 56.48; H, 3.80; N, 18.11.
d
ppm: 7.20e7.70 (m, 10H, ArH þ CH pyrrole), 8.60 (s, 1H, H at C5),
9.50 (s, 1H, H at C2). MS (m/z, %): 344.90 (Mþ, 100), 346.90 (Mþ2
,
32.94). Anal. Calcd for C19H12Cl N5 (345.79): C, 66.00; H, 3.50; N,
20.25. Found: C, 66.05; H, 3.65; N, 20.09.
4.1.3.4. 7-Phenyl-8-(p-tolyl)-7H-pyrrolo[3,2-e][1,2,4]triazolo[1,5-c]
pyrimidine (4d). 2.99 g, 92% (Method A), 2.79 g, 86% (Method B);
mp: 229e230 ꢁC; IR (KBr) cmꢀ1: 3073 (CeH aromatic), 2919
(CeH aliphatic), 1636, 1500 (C]C, C]N); 1H NMR (DMSO-d6)
4.1.2.3. 3-Amino-4-imino-6-(4-chlorophenyl)-7-phenyl-7H-pyrrolo
[2,3-d]pyrimidine (3c). (2.84 g, 85%); mp: 207e208 ꢁC; IR (KBr)
cmꢀ1: 3401, 3312 and 3245 (NH, NH2), 3097 (CeH aromatic), 1644
(C]N imine), 1596, 1500 (C]C, C]N), 749 (CeCl); 1H NMR
d
ppm: 2.27 (s, 3H, CH3), 7.09 (s, 1H, CH pyrrole), 7.13e7.60 (m, 9H,
(DMSO-d6)
d
ppm: 5.60 (s, 2H, NH2), 6.90 (s, 1H, CH pyrrole),
ArH), 8.58 (s, 1H, H at C5), 9.41 (s, 1H, H at C2); 13C NMR: 21.16 (CH3),
100.52, 106.05, 128.38, 128.83, 128.95, 129.03, 129.53, 129.62,
136.08, 136.44, 138.18, 139.87, 143.54, 148.50, 155.19 (15 type of Ca).
MS (m/z, %): 325.20 (Mþ, 100). Anal. Calcd for C20H15N5 (325.37): C,
73.83; H, 4.65; N, 21.52. Found: C, 73.52; H, 4.65; N, 21.42.
7.10e7.60 (m, 9H, ArH), 7.90 (s, 1H, H at C2), 8.11 (s, 1H, NH). MS (m/
z, %): 335.09 (Mþ,100), 337.09 (Mþ2, 30.30). Anal. Calcd for C18H14 Cl
N5 (335.79): C, 64.38; H, 4.20; N, 20.86. Found: C, 64.08; H, 4.15; N,
21.20.
4.1.2.4. 3-Amino-4-imino-6-(p-tolyl)-7-phenyl-7H-pyrrolo[2,3-d] ꢀ1
4.1.3.5. 7-Phenyl-8-(4-fluorophenyl)-7H-pyrrolo[3,2-e][1,2,4]triazolo
[1,5-c]pyrimidine (4e). 2.96 g, 90% (Method A), 2.86 g, 87%
(Method B); mp: 206e207 ꢁC; IR (KBr) cmꢀ1: 3060 (CeH aromatic),
1643, 1511 (C]C, C]N), 1229 (CeF); 1H NMR (DMSO-d6)
pyrimidine (3d). (2.77 g, 88%); mp: 204e205 ꢁC; IR (KBr) cm
:
3422, 3300 and 3200 (NH, NH2), 1637 (C]N imine),1595, 1499 (C]
C, C]N); 1H NMR (DMSO-d6)
d
ppm: 2.31 (s, 3H, CH3), 5.68 (s, 2H,
NH2), 6.81 (s, 1H, CH pyrrole), 6.89e7.70 (m, 9H, ArH), 7.89 (s, 1H, H
at C2), 8.40 (s, 1H, NH). MS (m/z, %): 315.15 (Mþ, 100). Anal. Calcd for
C19H17N5 (315.37): C, 72.36; H, 5.39; N, 22.21. Found: C, 72.66; H,
5.26; N, 21.97.
d
ppm: 7.11e7.60 (m, 10H, ArH þ CH pyrrole), 8.62 (s, 1H, H at C5),
9.47 (s, 1H, H at C2). MS (m/z, %): 329.95 (Mþ, 12.61).Anal.Calcd for
C19H12 F N5 (329.33): C, 69.29; H, 3.67; N, 21.27. Found: C, 69.35; H,
3.32; N, 20.95.
4.1.2.5. 3-Amino-4-imino-6-(4-fluorophenyl)-7-phenyl-7H-pyrrolo
[2,3-d]pyrimidine (3e). (2.67 g, 84%); mp: 203e204 ꢁC; IR (KBr)
cmꢀ1: 3422, 3300 and 3200 (NH, NH2), 3071 (CeH aromatic),
1637 (C]N imine), 1595, 1499 (C]C, C]N), 1173 (CeF); 1H
4.1.4. General procedure for the synthesis of compounds (5aee)
A mixture of 1aee (0.01 mol) in formic acid (85%) (20 mL) was
refluxed for 4 h. Then the reaction mixture was cooled and the
separated solid was filtered, washed with ethanol, dried and crys-
tallized from ethanol.
NMR (DMSO-d6)
d ppm: 5.64(s, 2H, NH2), 6.94 (s, 1H, CH
pyrrole), 7.20e7.41 (m, 9H, ArH), 7.90 (s, 1H, H at C2), 8.00 (s, 1H,
NH). MS (m/z, %): 319.12 (Mþ, 100). Anal. Calcd for C18H14 F N5
(319.34): C, 67.70; H, 4.42; N, 21.93. Found: C, 67.66; H, 4.05; N,
21.64.
4.1.4.1. 6,7-Diphenyl-3,7-dihydro-pyrrolo[2,3-d]pyrimidin-4-one
(5a). (1.37 g, 48%); mp: 292e293 ꢁC; IR (KBr) cmꢀ1: 3108 (NH),
1680 (C]O), 1596, 1484 (C]C, C]N); 1H NMR (DMSO-d6)
d
ppm: 6.80e7.90 (m, 11H, ArH þ CH pyrrole), 8.20 (s, 1H, H at C2),
4.1.3. General procedure for the synthesis of (4aee)
10.10 (s, 1H, NH); 13C NMR: 104.31, 106.55, 124.62, 128.01, 130.53,
135.39, 139.12, 140.11, 143.41, 147.73, 149.35, 157.69. MS (m/z, %):
287.11 (Mþ, 100). Anal. Calcd for C18H13N3O (287.32): C, 75.25; H,
4.56; N, 14.63. Found: C, 75.50; H, 4.43; N, 14.67.
Method A: A mixture of 3aee (0.01 mol) in formic acid (85%)
(15 mL) was heated under reflux for 4 h. The cold reaction mixture
was poured onto crushed ice and the solid obtained was filtered,
washed with water, dried and recrystallized from ethanol.
Method B: A mixture of 7aee (0.01 mol) in formic acid (85%)
(20 mL) was heated under reflux for 8 h. The cold reaction mixture
was poured onto crushed ice and the solid obtained was filtered,
washed with water, dried and recrystallized from ethanol.
4.1.4.2. 6-(4-Bromophenyl)-7-phenyl-3,7-dihydro-pyrrolo[2,3-d]pyr-
imidin-4-one (5b). (2.23 g, 84%); mp: 340e341 ꢁC; IR (KBr) cmꢀ1
:
3427 (NH), 1668 (C]O), 1588, 1484 (C]C, C]N); 1H NMR (CDCl3)
ppm: 6.90e7.40 (m, 10H, ArH þ CH pyrrole), 7.90 (s, 1H, H at C2),
d

5248
K.M. Hassan Hilmy et al. / European Journal of Medicinal Chemistry 45 (2010) 5243e5250
11.60 (s, 1H, NH, D2O exchangeable). MS (m/z, %): 365.00 (Mþ, 100),
367.00 (Mþ2, 94.32). Anal. Calcd for C18H12BrN3O (266.21): C, 59.03;
H, 3.30; N, 11.47. Found: C, 59.23; H, 3.50; N, 11.5.
(319.09): C, 71.36; H, 4.41; N, 13.14. Found: C, 71.49; H, 4.13; N,
13.40.
4.1.5.5. 4-Chloro-6-(4-fluorophenyl)-7-phenyl-7H-pyrrolo[2,3-d]
pyrimidine (6e). (3.10 g, 96%); mp: 112e113 ꢁC; IR (KBr) cmꢀ1: 3057
(CeH aromatic),1581,1510 (C]C, C]N),1225 (CeF), 755 (CeCl); 1H
4.1.4.3. 6-(4-Chlorophenyl)-7-phenyl-3,7-dihydro-pyrrolo[2,3-d]pyr-
imidin-4-one (5c). (2.79 g, 87%); mp: 320e321 ꢁC; IR (KBr) cmꢀ1
:
3427 (NH), 1668 (C]O), 1588, 1484 (C]C, C]N); 1H NMR (CDCl3)
NMR (DMSO-d6) d ppm: 6.90 (s, 1H, CH pyrrole), 7.00e8.10 (m, 9H,
d
ppm: 6.90e8.00 (m, 10H, ArH þ CH pyrrole), 8.10 (s, 1H, H at C2),
ArH), 8.60 (s, 1H, H at C2). MS (m/z, %): 321.95 (Mþ, 100), 323.95
(Mþ2, 50.57). Anal. Calcd for C18H11N3ClF (323.75): C, 66.78; H, 3.42;
N, 12.98. Found: C, 66.75; H, 3.35; N, 12.88.
11.70 (s,1H, NH). MS (m/z, %): 321.07 (Mþ,100), 323.05 (Mþ2, 32.00).
Anal. Calcd for C18H12ClN3O (321.76): C, 67.19; H, 3.76; N, 13.06.
Found: C, 67.30; H, 3.50; N, 13.20.
4.1.6. General procedure for the synthesis of compounds (7aee)
A mixture of 6aee (0.01 mol) in (99%) hydrazine hydrate (99%)
(10 mL) and ethanol (10 mL) was refluxed for 2 h. Then the cold
reaction mixture was poured onto crushed ice, stirred well, filtered,
washed with water, dried and recrystallized from ethanol.
4.1.4.4. 6-(p-Tolyl)-7-phenyl-3,7-dihydro-pyrrolo[2,3-d]pyrimidin-4-
one (5d). (2.40 g, 80%); mp: 302e303 ꢁC; IR (KBr) cmꢀ1: 3427 (NH),
1668 (C]O), 1588, 1484 (C]C, C]N); 1H NMR (CDCl3)
d ppm: 2.30
(s, 3H, CH3), 6.90e8.00 (m, 10H, ArH þ CH pyrrole), 8.10 (s, 1H, H at
C2), 11.70 (s, 1H, NH). MS (m/z, %): 301.12 (Mþ, 100). Anal. Calcd for
C19H15N3O (301.34): C, 75.73; H, 5.02; N, 13.94. Found: C, 75.50; H,
4.71; N, 13.20.
4.1.6.1. 6,7-Diphenyl-4-hydrazino-7H-pyrrolo[2,3-d]pyrimidine
(7a). (2.64 g, 88%); mp: 188e189 ꢁC; IR (KBr) cmꢀ1: 3404, 3326 and
3200 (NH, NH2), 3040 (CeH aromatic), 1589, 1496 (C]C, C]N); 1H
4.1.4.5. 6-(4-Fluorophenyl)-7-phenyl-3,7-dihydro-pyrrolo[2,3-d]pyr-
NMR (DMSO-d6) d ppm: 4.20 (s, 2H, NH2), 6.90e7.60 (m, 11H,
imidin-4-one (5e). (2.47 g, 83%); mp: 304e305 ꢁC; IR (KBr) cmꢀ1
:
ArH þ CH pyrrole), 7.90 (s, 1H, H at C2), 8.60 (s, 1H, NH). MS (m/z, %):
301.00 (Mþ, 100). Anal. Calcd for C18H15N5 (301.35): C, 71.74; H,
5.02; N, 23.24. Found: C, 71.62; H, 5.04; N, 22.95.
3427 (NH), 1668 (C]O), 1588, 1484 (C]C, C]N); 1H NMR (CDCl3)
d
ppm: 6.90e7.50 (m, 10H, ArH þ CH pyrrole), 8.00 (s, 1H, H at C2),
12.30 (s, 1H, NH). MS (m/z, %): 305.00 (Mþ, 100). Anal. Calcd for
C18H12FN3O (305.31): C, 70.81; H, 3.96; N, 13.76. Found: C, 70.49; H,
3.54; N, 13.52.
4.1.6.2. 6-(4-Bromophenyl)-7-phenyl-4-hydrazino-7H-pyrrolo[2,3-d]
pyrimidine (7b). (3.26 g, 86%); mp: 227e228 ꢁC; IR (KBr) cmꢀ1
:
3400, 3309 and 3200 (NH, NH2), 3062 (CeH aromatic), 1594, 1495
(C]C, C]N), 564 (CeBr); 1H NMR (DMSO-d6)
ppm: 4.20 (s, 2H,
NH2), 6.90e7.60 (m, 10H, ArH þ CH pyrrole), 7.90 (s, 1H, H at C2),
8.60 (s, 1H, NH). MS (m/z, %): 379.00 (Mþ, 50.93), 381.00 (Mþ2
41.91). Anal. Calcd for C18H14 Br N5 (380.24): C, 56.86; H, 3.71; N,
18.42. Found: C, 56.48; H, 3.34; N, 18.03.
4.1.5. General procedure for the synthesis of compounds (6aee)
A mixture of 5aee (0.01 mol) in phosphorous oxychloride
(20 mL) was refluxed for 10 h. Then the cold reaction mixture was
poured onto crushed ice, stirred well, filtered, washed with water,
dried and recrystallized from ethanol.
d
,
4.1.5.1. 4-Chloro-6,7-diphenyl-7H-pyrrolo[2,3-d]pyrimidine
4.1.6.3. 6-(4-Chlorophenyl)-7-phenyl-4-hydrazino-7H-pyrrolo[2,3-d]
(6a). (2.62 g, 86%); mp: 152e153 ꢁC; IR (KBr) cmꢀ1: 3039 (CeH
pyrimidine (7c). (3.04 g, 91%); mp: 213e214 ꢁC; IR (KBr) cmꢀ1
:
aromatic), 1561, 1485 (C]C, C]N), 756 (CeCl); 1H NMR (DMSO-d6)
3400, 3306, 3200 and 3150 (NH, NH2), 3040 (CeH aromatic),
d
ppm: 6.90e8.10 (m, 11H, ArH þ CH pyrrole), 8.60 (s, 1H, H at C2).
1595, 1496 (C]C, C]N), 771 (CeCl); 1H NMR (DMSO-d6)
d
ppm:
MS (m/z, %): 305.05 (Mþ, 84.75), 307.05 (Mþ2, 29.79). Anal. Calcd for
C18H12Cl N3 (305.76): C, 70.61; H, 3.96; N, 13.74. Found: C, 70.89; H,
3.75; N, 13.64.
4.20 (s, 2H, NH2), 6.85 (s, 1H, CH pyrrole), 7.00e7.60 (m, 9H, ArH),
7.89 (s, 1H, H at C2), 8.60 (s, 1H, NH). MS (m/z, %): 334.90 (Mþ, 100),
336.90 (Mþ2, 37.63). Anal. Calcd for C18H14 Cl N5 (335.79): C, 64.38;
H, 4.20; N, 20.86. Found: C, 64.72; H, 4.58; N, 20.66.
4.1.5.2. 6-(4-Bromophenyl)-4-chloro-7-phenyl-7H-pyrrolo[2,3-d]
pyrimidine (6b). (3.15 g, 89%); mp: 179e180 ꢁC; IR (KBr) cmꢀ1
:
4.1.6.4. 6-(p-Tolyl)-7-phenyl-4-hydrazino-7H-pyrrolo[2,3-d]pyrimi-
dine (7d). (2.83 g, 90%); mp: 172e173 ꢁC; IR (KBr) cmꢀ1: 3404, 3326
and 3200 (NH, NH2), 3040 (CeH aromatic),1589,1496 (C]C, C]N);
3048 (CeH aromatic), 1579, 1482 (C]C, C]N), 771 (CeCl), 594
(CeBr); 1H NMR (DMSO-d6)
d
ppm: 7.10e8.10 (m, 10H, ArH þ CH
pyrrole), 8.60 (s, 1H, H at C2). MS (m/z, %): 384.00 (Mþ, 100), 385.00
(Mþ2, 80.00), 387.00 (Mþ4, 27.00). Anal. Calcd for C18H11Br Cl N3
(384.66): C, 56.20; H, 2.88; N, 10.92. Found: C, 56.46; H, 3.01; N,
10.92.
1H NMR (DMSO-d6)
d ppm: 2.40 (s, 3H, CH3), 4.70 (s, 2H, NH2), 6.91
(s, 1H, CH pyrrole), 7.13e8.01 (m, 9H, ArH), 8.23 (s, 1H, H at C2), 9.23
(s,1H, NH). MS (m/z, %): 315.00 (Mþ, 88.36). Anal. Calcd for C19H17N5
(315.37): C, 72.36; H, 5.43; N, 22.21. Found: C, 72.21; H, 5.19; N,
22.12.
4.1.5.3. 4-Chloro-6-(4-chlorophenyl)-7-phenyl-7H-pyrrolo[2,3-d]
pyrimidine (6c). (3.06 g, 90%); mp: 160e161 ꢁC; IR [Br] cmꢀ1: 3047
(CeH aromatic), 1581, 1484 (C]C, C]N), 771 (CeCl); 1H NMR
4.1.6.5. 6-(4-Fluorophenyl)-7-phenyl-4-hydrazino-7H-pyrrolo[2,3-d]
pyrimidine (7e). (2.55 g, 80%); mp: 225e226 ꢁC; IR (KBr) cmꢀ1
:
(DMSO-d6)
d
ppm: 6.89 (s, 1H, CH pyrrole), 7.09e8.00 (m, 9H, ArH),
3424, 3349, 3313 and 3196 (NH, NH2), 3062 (CeH aromatic),
8.62 (s, 1H, H at C2). MS (m/z, %): 338.00 (Mþ, 100), 341.00(Mþ2
,
1589,1511 (C]C, C]N), 1220 (CeF); 1H NMR (DMSO-d6)
d
ppm:
87.54), 342.00 (Mþ4, 23.76). Anal. Calcd for C18H11 Cl2N3 (340.21): C,
63.55; H, 3.26; N, 12.35. Found: C, 63.52; H, 3.22; N, 12.31.
4.02 (s, 2H, NH2), 7.03(s, 1H, CH pyrrole), 7.10e7.47(m, 9H, ArH),
8.20 (s, 1H, H at C2), 8.89 (s, 1H, NH). MS (m/z, %): 318.95 (Mþ, 100).
Anal. Calcd for C18H14 F N5 (319.34): C, 67.70; H, 4.42; N, 21.93.
Found: C, 67.32; H, 4.30; N, 21.92.
4.1.5.4. 4-Chloro-7-phenyl-6-p-Tolyl-7H-pyrrolo[2,3-d]pyrimidine
(6d). (2.29 g, 79%); mp: 119e120 ꢁC; IR (KBr) cmꢀ1: 3105 (CeH
aromatic), 2919 (CeH aliphatic), 1561, 1485 (C]C, C]N), 756
4.1.7. General procedure for the synthesis of compounds (8aee)
An aqueous solution of (20% w/v) sodium nitrite (4.2 mL) was
slowly added in portions to a stirred mixture of 7aee (0.01 mol) in
acetic acid (40 mL) at 0e5 ꢁC. The reaction mixture was then further
(CeCl); 1H NMR (DMSO-d6)
d ppm: 2.30 (s, 3H, CH3), 7.01 (s, 1H, CH
pyrrole), 7.20e8.11 (m, 9H, ArH), 8.60 (s, 1H, H at C2). MS (m/z, %):
318.05 (Mþ, 100), 320.05 (Mþ2, 53.54). Anal. Calcd for C19H14 Cl N3

K.M. Hassan Hilmy et al. / European Journal of Medicinal Chemistry 45 (2010) 5243e5250
5249
stirred for 2 h at the same temperature, then it was diluted with
cold water and the solid obtained was filtered, washed with water,
dried and crystallized from ethanol.
Anal. Calcd for C18H13 Cl N4 (320.78): C, 67.40; H, 4.08; N, 17.47.
Found: C, 67.19; H, 3.85; N, 17.42.
4.1.8.3. 7-Phenyl-6-p-tolyl-7H-pyrrolo[2,3-d]pyrimidin4-amine
(9d). (2.70 g, 90%); mp: 238e239 ꢁC; IR (KBr) cmꢀ1: 3404, 3326
and 3200 (NH2), 3040 (CeH aromatic), 1589, 1496 (C]C, C]N); 1H
4.1.7.1. 7,8-Diphenyl-7H-pyrrolo[3,2-e]tetrazolo[1,5-c]pyrimidine
(8a). (2.83 g, 91%); mp: 199e200 ꢁC; IR (KBr) cmꢀ1: 3100 (CeH
aromatic),1629,1501 (C]C, C]N); 1H NMR (DMSO-d6)
d
ppm: 6.84
NMR (DMSO-d6) d ppm: 2.25 (s, 3H, CH3), 6.83 (s, 2H, NH2), 6.84 (s,
(s, 1H, CH pyrrole), 7.34e7.87 (m, 10H, ArH), 9.85 (s, 1H, H at C5). MS
(m/z, %): 312.00 (Mþ, 13.44). Anal. Calcd for C18H12N6 (312.23): C,
69.22; H, 3.87; N, 26.91. Found: C, 69.02; H, 3.82; N, 27.11.
1H, CH pyrrole), 7.00e7.90 (m, 9H, ArH), 8.00 (s, 1H, CH pyrimi-
dine). MS (m/z, %): 300.00 (Mþ, 33.00). Anal. Calcd for C19H16N4
(300.36): C, 75.98; H, 5.37; N, 18.65. Found: C, 75.71; H, 5.22; N,
18.51.
4.1.7.2. 8-(4-Bromo-phenyl)-7-phenyl-7H-pyrrolo[3,2-e]tetrazolo
[1,5-c]pyrimidine (8b). (3.44 g, 88%); mp: 202e203 ꢁC; IR (KBr)
cmꢀ1: 3061 (CeH aromatic), 1644, 1499 (C]C, C]N), 555 (CeBr);
4.1.9. General procedure for the synthesis of compounds (10a,c,d)
A mixture of 9a,c,d (0.01 mol) and acetaldehyde (10 mL) was
refluxed in ethanol (20 mL) for 4 h. The cold reaction mixture was
concentrated, the separated solid filtered off and recrystallized
from ethanol.
1H NMR (DMSO-d6)
d
ppm: 7.20e7.70 (m, 10H, ArH þ CH pyrrole),
9.90 (s, 1H, H at C5). MS (m/z, %): 390.00 (Mþ, 100), 392.00 (Mþ2
,
94.00). Anal. Calcd for C18H11 Br N6 (391.22): C, 55.10; H, 2.80; N,
21.42. Found: C, 55.10; H, 3.11; N, 21.11.
4.1.9.1. N-Ethylidene-6,7-diphenyl-7H-pyrrolo[2,3-d]pyrimidin-4-
4.1.7.3. 8-(4-Chloro-phenyl)-7-phenyl-7H-pyrrolo[3,2-e]tetrazolo
[1,5-c]pyrimidine (8c). (3.22 g, 93%); mp: 210e211 ꢁC; IR (KBr)
cmꢀ1: 3099 (CeH aromatic),1631,1501 (C]C, C]N), 749 (CeCl); 1H
amine (10a). (2.96 g, 95%); mp: 121e122 ꢁC; 1H NMR (DMSO-d6)
d
ppm: 1.12 (d, 3H, -CHCH3), 1.30 (q, 1H, -CHCH3), 6.76 (s, 1H, CH
pyrrole), 6.80e8.00 (m, 10H, ArH), 8.45 (s, 1H, CH pyrimidine). MS
(m/z, %): 312.00 (Mþ, 100). Anal. Calcd for C20H16N4 (312.37): C,
76.92; H, 5.13; N, 17.95. Found: C, 76.64; H, 4.89; N, 17.56.
NMR (DMSO-d6)
d
ppm: 7.33e7.58 (m, 10H, ArH þ CH pyrrole), 9.88
(s, 1H, H at C5). MS (m/z, %): 346.00 (Mþ, 10.54), 348.00 (Mþ2, 3.95).
Anal. Calcd for C18H11 Cl N6 (346.77): C, 62.34; H, 3.20; N, 24.23.
Found: C, 62.71; H, 3.22; N, 23.86.
4.1.9.2. 6-(4-Chlorophenyl)-N-ethylidene-7-phenyl-7H-pyrrolo[2,3-
d]pyrimidin-4-amine (10c). (3.18 g, 92%); mp: 116e117 ꢁC; 1H NMR
4.1.7.4. 7-Phenyl-8-p-tolyl-7H-pyrrolo[3,2-e]tetrazolo[1,5-c]pyrimi-
dine (8d). (2.70 g, 83%); mp: 209e210 ꢁC; IR (KBr) cmꢀ1: 3072 (CeH
aromatic), 2925 (CeH aliphatic) 1629, 1502 (C]C, C]N); 1H NMR
(DMSO-d6) d ppm: 1.12 (d, 3H, -CHCH3), 1.30 (q, 1H, -CHCH3), 6.70
(s, 1H, CH pyrrole), 6.80e8.00 (m, 9H, ArH), 8.45 (s, 1H, CH
pyrimidine). MS (m/z, %): 346.00 (Mþ, 100), 348.00 (Mþ2, 38.00).
Anal. Calcd for C20H15 Cl N4 (346.81): C, 69.26; H, 4.36; N, 16.15.
Found: C, 69.02; H, 3.98; N, 16.11.
(DMSO-d6)
d
ppm: 2.27 (s, 3H, CH3), 7.00e7.59 (m, 10H, ArH þ CH
pyrrole), 9.86 (s, 1H, H at C5). MS (m/z, %): 326.00 (Mþ, 100). Anal.
Calcd for C19H14N6 (326.35): C, 69.92; H, 4.32; N, 25.75. Found: C,
69.78; H, 4.40; N, 25.52.
4.1.9.3. N-Ethylidene-7-phenyl–6-p-tolyl-7H-pyrrolo[2,3-d]pyr-
imidin-4-amine (10d). (3.03 g, 93%); mp: 130e131 ꢁC; 1H NMR
4.1.7.5. 8-(4-Fluoro-phenyl)-7-phenyl-7H-pyrrolo[3,2-e]tetrazolo
[1,5-c]pyrimidine (8e). (2.97 g, 90%); mp: 162e163 ꢁC; IR (KBr)
cmꢀ1: 3077 (CeH aromatic), 1633, 1511 (C]C, C]N), 1229 (CeF);
(DMSO-d6) d ppm: 1.11 (d, 3H, -CHCH3), 1.50 (q, 1H, -CHCH3),
2.25 (s, 3H, CH3), 6.70 (s, 1H, CH pyrrole), 6.80e7.50 (m, 9H, ArH),
8.40 (s, 1H, CH pyrimidine). MS (m/z, %): 326.15 (Mþ, 100). Anal.
Calcd for C21H18N4 (326.39): C, 77.28; H, 5.56; N, 17.17. Found: C,
76.92; H, 5.28; N, 17.11.
1H NMR (DMSO-d6)
d
ppm: 7.20e7.60 (m, 10H, ArH þ CH
pyrrole), 9.86 (s, 1H, H at C5); 13C NMR: 101.48, 102.85, 115.39,
116.00, 116.46, 128.61, 128.89, 129.35, 130.53, 131.15, 133.60,
140.40, 143.34, 146.03. MS (m/z, %): 329.95 (Mþ, 12.61). Anal.
Calcd for C18H11 F N6 (330.32): C, 65.45; H, 3.36; N, 25.44. Found:
C, 65.22; H, 3.40; N, 25.27.
4.1.10. General procedure for the synthesis of compounds (11a,c,d)
A mixture of 1a,c,d (0.01 mol) and urea (0.01 mol) was refluxed
in glacial acetic acid and hydrochloric acid (3:1) for 4 h. After that
the cold reaction mixture was poured into ice cold water, filtered
and recrystallized from chloroform.
4.1.8. General procedure for the synthesis of compounds (9a,c,d)
A mixture of 1a,c,d (0.01 mol) and formamide (10 mL) was
refluxed for 4 h, the reaction mixture was then concentrated and
poured into ice cold water. The separated solid was filtered off and
recrystallized from ethanol.
4.1.10.1. 6,7-Diphenyl-7H-pyrrolo[2,3-d]pyrimidine-2,4-diamine
(11a). (2.34 g, 78%); mp: 135e136 ꢁC; IR (KBr) cmꢀ1: 3200, 3100
(NH2), 3060 (CeH aromatic), 1595, 1497 (C]C, C]N); 1H NMR
(DMSO-d6)
d ppm: 6.70 (s, 4H, 2NH2), 7.00 (s, 1H, CH pyrrole),
4.1.8.1. 6,7-Diphenyl-7H-pyrrolo[2,3-d]pyrimidin-4-amine
7.10e7.80 (m, 10H, ArH). MS (m/z, %): 301.00 (Mþ, 100). Anal. Calcd
for C18H15N5 (301.35): C, 71.74; H, 5.02; N, 23.24 Found: C, 71.55; H,
4.82; N, 23.01.
(9a). (2.71 g, 95%); mp: 240e241 ꢁC; IR (KBr) cmꢀ1: 3458, 3299 and
3120 (NH2), 3050 (CeH aromatic),1589,1498 (C]C, C]N); 1H NMR
(DMSO-d6)
d ppm: 6.85 (s, 2H, NH2), 6.90 (s, 1H, CH pyrrole),
7.20e8.00 (m, 10H, ArH), 8.52 (s, 1H, CH pyrimidine). MS (m/z, %):
286.00 (Mþ, 60.20). Anal. Calcd for C18H14N4 (286.33): C, 75.50; H,
4.93; N, 19.57. Found: C, 75.21; H, 4.52; N, 19.38.
4.1.10.2. 6-(4-Chlorophenyl)-7-phenyl-7H-pyrrolo[2,3-d]pyrimidine-
2,4-diamine (11c). (2.98 g, 89%); mp: 114e115 ꢁC; IR (KBr) cmꢀ1
:
3200, 3100 (NH2), 3065 (CeH aromatic), 1H NMR (DMSO-d6)
d
ppm: 6.79 (s, 4H, 2NH2), 6.81 (s, 1H, CH pyrrole), 6.90e8.40 (m,
4.1.8.2. 6-(4-Chlorophenyl)-7-phenyl-7H-pyrrolo[2,3-d]pyrimidin4-
amine (9c). (2.72 g, 85%); mp: 260e261 ꢁC; IR (KBr) cmꢀ1: 3400,
3306, 3200 and 3150 (NH2), 3040 (CeH aromatic),1595,1496 (C]C,
9H, ArH). MS (m/z, %): 335.00 (Mþ, 100), 337.00 (Mþ2, 14.20). Anal.
Calcd for C18H14 Cl N5 (335.79): C, 64.38; H, 4.20; N, 20.86. Found: C,
64.12; H, 3.82; N, 20.68.
C]N), 771 (CeCl); 1H NMR (DMSO-d6)
d ppm: 6.85 (s, 2H, NH2),
6.89 (s, 1H, CH pyrrole), 7.20e8.00 (m, 9H, ArH), 8.52 (s, 1H, CH
4.1.10.3. 7-Phenyl-6-p-tolyl-7H-pyrrolo[2,3-d]pyrimidine-2,4-
pyrimidine). MS (m/z, %): 320.00 (Mþ, 100), 322.00 (Mþ2, 30.00).
diamine (11d). (2.74 g, 87%); mp: 101e102 ꢁC; IR (KBr) cmꢀ1: 3200,

5250
K.M. Hassan Hilmy et al. / European Journal of Medicinal Chemistry 45 (2010) 5243e5250
3100 (NH2), 3041 (CeH aromatic), 2925 (CeH aliphatic), 1602,
1497 (C]C, C]N); 1H NMR (DMSO-d6)
ppm: 2.28 (s, 3H, CH3),
4.2.3. Agar well diffusion technique [18]
d
The in vitro antibacterial and antifungal activity of compounds
were tested by the diffusion agar technique [18]. The diffusion agar
technique was followed to determine the minimum inhibitory
concentration (MIC) of all the synthesized compounds. With
a sterile loop, pure colonies of the bacteria and fungi culture were
picked up. The colonies were suspended in 5 mL of sterile saline.
Well containing the material were pre-incubated for 1 h at refrig-
erator followed by incubation for bacteria 24 h at 37 ꢂ 1 ꢁC and for
fungi 48 h at 28 ꢂ 1 ꢁC. After incubation, the diameter of the
inhibition zone was measured. The MIC is the lowest concentration
(highest dilution) of active compound that makes inhibition for
microbial growth i.e. the next dilution not makes inhibition in
microbial growth [19e21].
7.00 (s, 4H, 2NH2), 7.20 (s, 1H, CH pyrrole), 7.30e7.88 (m, 9H, ArH);
13C NMR: 24.57 (CH3), 101.41, 104.2, 120.72, 127.83, 128.0, 128.33,
128.45, 128.80, 129.14, 134.10, 143.36, 173.58, 197.84, 207.8. MS (m/z,
%): 315.00 (Mþ, 31.30). Anal. Calcd for C19H17N5 (315.37): C, 72.36;
H, 5.43; N, 22.21. Found: C, 72.02; H, 5.58; N, 22.10.
4.1.11. General procedure for the synthesis of compounds (12a,c,d)
A mixture of 1a,c,d (0.01 mol) and acetamide (0.01 mol) was
refluxed in glacial acetic acid and hydrochloric acid (3:1) for 4 h.
After that the cold reaction mixture was poured into ice cold water,
filtered and recrystallized from chloroform.
4.1.11.1. 2-Methyl-4-amino-6,7-diphenyl-7H-pyrrolo[2,3-d]pyrimi-
dine (12a). (2.85 g, 95%); mp: 135e136 ꢁC; IR (KBr) cmꢀ1: 3345,
3116 (NH2), 3059 (CeH aromatic), 2923 (CeH aliphatic), 1595,
Acknowledgement
1497 (C]C, C]N); 1H NMR (DMSO-d6)
d ppm: 2.50 (s, 3H, CH3),
The authors would like to acknowledge Prof. Dr. Esmat Bauomy
Ali, Biochemistry Department, Al-Azahar University, Faculty of
Medicine for girls, Nasr City, Cairo, Egypt for her help in biological
activity work.
6.80 (s, 2H, NH2), 6.81 (s, 1H, CH pyrrole), 6.84e8.46 (m, 10H, ArH).
MS (m/z, %): 300.00 (Mþ, 16.70). Anal. Calcd for C19H16N4 (300.36):
C, 75.98; H, 5.37; N, 18.65. Found: C, 75.92; H, 5.69; N, 18.59.
4.1.11.2. 2-Methyl-4-amino-6-(4-chlorophenyl)-7-phenyl-7H-pyrrolo
[2,3-d]pyrimidine (12c). (2.97 g, 89%); mp: 102e103 ꢁC; IR (KBr)
References
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:
3345, 3116 (NH2), 3059 (CeH aromatic), 2923 (CeH
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:
3345, 3116 (NH2), 3059 (CeH aromatic), 2850 (CeH aliphatic),
1595,1497 (C]C, C]N); 1H NMR (DMSO-d6)
d
ppm: 2.30 (s, 3H,
CH3), 2.50 (s, 3H, CH3 at C2), 6.79 (s, 2H, NH2), 6.82 (s, 1H, CH
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76.13; H, 5.91; N, 18.15.
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4.2.2. Culture of microorganisms
Bacteria and fungal species used were obtained from Microbi-
ology Department of Al-Azahar University, Faculty of Medicine for
girls, Nasr City, Cairo, Egypt, namely S. aureus (NCTC-7447), E. coli
(NCTC-10416), C. albicans (ATCC-10145). The bacterial strains were
maintained on MHA (Mueller-Hinton Agar) medium for 24 h at
37 ꢂ 1 ꢁC and fungi were maintained on SDS (Sabouraud Dextrose
Agar) for 48 h at 28 ꢂ 1 ꢁC. The bacteria and fungi inocula were
prepared by suspension in 5 mL of sterile saline for colonies from
culture on MHA and SDA medium.