Synthesis and anti-microbial activity of some 1- substituted amino-4,6-dimethyl-2-oxo-pyridine-3-carbonitrile derivatives

Article abstract of DOI:10.1016/j.ejmech.2011.08.018

A new series of 1- substituted amino-4,6-dimethyl-2-oxo-pyridine-3- carbonitrile such as hydrazide hydrazones 3a-h; ethane-1,2-diaminopyridine 6; phthalimidopyridines 8a,b; hydrazides 10a,b; urea 11a and thiourea 11b were synthesized in a good to excellent yield in step efficient process, using 1-amino-4,6-dimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile (1) as a key intermediate. The antibacterial and antifungal activities of the synthesized compounds were evaluated. The obtained data indicated that the majority of the tested compounds exhibited both antibacterial and antifungal activities, particularly compounds 8a and 8b showed a comparable effect to a well known antibacterial and antifungal agents.

Full text of DOI:10.1016/j.ejmech.2011.08.018

European Journal of Medicinal Chemistry 46 (2011) 5057e5064
Contents lists available at SciVerse ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Synthesis and anti-microbial activity of some 1- substituted amino-4,
6-dimethyl-2-oxo-pyridine-3-carbonitrile derivatives
,
,
c
,
d
Rizk E. Khidre a c, Ameen A. Abu-Hashem b , Mohamed El-Shazly
*
a Chemical Industries Division, National Research Centre, Dokki 12622, Giza, Egypt
b Department of Photochemistry, National Research Centre, Dokki 12622, Giza, Egypt
c Chemistry department, Faculty of Science, Jazan University, Saudi Arabia
d Department of Pharmacognosy, Faculty of Pharmacy, Ain Shams 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 new series of 1- substituted amino-4,6-dimethyl-2-oxo-pyridine-3-carbonitrile such as hydrazide
hydrazones 3a-h; ethane-1,2-diaminopyridine 6; phthalimidopyridines 8a,b; hydrazides 10a,b; urea 11a
and thiourea 11b were synthesized in a good to excellent yield in step efficient process, using 1-amino-
4,6-dimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile (1) as a key intermediate. The antibacterial and
antifungal activities of the synthesized compounds were evaluated. The obtained data indicated that the
majority of the tested compounds exhibited both antibacterial and antifungal activities, particularly
compounds 8a and 8b showed a comparable effect to a well known antibacterial and antifungal agents.
Published by Elsevier Masson SAS.
Received 8 May 2011
Received in revised form
6 July 2011
Accepted 12 August 2011
Available online 25 August 2011
Keywords:
Pyridines
Hydrazide hydrazones
Urea and thiourea derivatives
Anti-microbial and antifungal activities
Structure-activity relationship (SAR)
1. Introduction
previous work in the synthesis of biologically active compounds
[22e25], we synthesized newer pyridine derivatives by facile
Hydrazines and their derivatives constitute an important class
of compounds that has found wide utility in organic synthesis [1,2].
The chemistry of carbon-nitrogen double bond of hydrazone is
becoming the backbone of condensation reaction in benzo-fused N-
heterocycles [3], also it constitutes an important class of
compounds for new drug development [4]. A number of hydrazide
hydrazone derivatives have been claimed to possess interesting
bioactivity such as anti-microbial [1], antitubercular [5,6], anti-
convulsant [7], analgesic [8], anti-inflammatory [9,10], antiplatelet
aggregation [11], anticancer [12,13], antifungal [14], antiviral [15],
antibacterial [16], and antimalarial [17] activities. Aroylhydrazide
hydrazones containing hetero-ring such as pyridine ring have
attracted special attention [18,19]. Also in relation to the biologi-
cally active compounds containing carbon-nitrogen bond, natural
and synthetic compounds with cyanopyridine moiety proved to
exhibit significant antibacterial [20] and antifungal [21] activities.
Encouraged by these observations and in continuation to our
methods. Antibacterial and antifungal activities of the prepared
compounds have been investigated, and the results showed that
some of the synthesized compounds have broad spectrum anti-
bacterial and antifungal activities.
2. Results and discussion
2.1. Chemistry
The synthetic procedures adopted to obtain the target
compounds are depicted in Schemes 1e3. Reaction of 1-amino-4,6-
dimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile (1), which was
prepared according to the reported method [26,27], with molar
quantity of aryl aldehydes 2aeh namely, 4-flourobenzaldehyde 2a,
thiophen-2-carbaldehyde 2b, 2-chloroquinoline-3-carbaldehyde
2c, 2-chloro-6-methyl quinoline-3-carbaldehyde 2d, 5-chloro-3-
methyl-1-phenyl-1H-pyrazole-4-carbaldehyde 2e, tetrazolo[1,5-a]
quinoline-4-carbaldehyde 2f, 7-methyltetrazolo[1,5-a]quinoline-4-
carbaldehyde 2g, and 3-(benzofuran-2-yl)-1-phenyl-1H-pyrazole-
4-carbaldehyde 2h in absolute ethanol containing few drops of
glacial acetic acid at reflux temperature to afford hydrazide
hydrazones 3aeh in excellent yield.
* Corresponding author. Department of Photochemistry, National Research
Centre, Dokki 12622, Giza, Egypt. Tel.: þ2 012 521 1700, þ966 56 351 0497;
fax: þ202 33370931.
E-mail address: aminaliabuhashem@yahoo.com (A.A. Abu-Hashem).
0223-5234/$ e see front matter Published by Elsevier Masson SAS.
doi:10.1016/j.ejmech.2011.08.018

5058
R.E. Khidre et al. / European Journal of Medicinal Chemistry 46 (2011) 5057e5064
Scheme 1. Synthesis of hydrazide hydrazone derivatives. Reagents and conditions: absolute ethanol, glacial acetic acid (1 mL), reflux, 5e8 h, 75e90% yield.
On the other hand, hydrazide hydrazone 3c was synthesized, by
at
d
8.12e8.55 corresponding to CH ¼ N- group of hydrazone. Two
2.20e2.29 ppm and
another route, from the reaction of cyanoacetylhydrazone, which
was prepared by the reaction of cyanoacetyl hydrazide with alde-
hydes, and acetyl acetone [28] e.g. 2-chloroquinoline-3-
carbaldehyde 2c. The reaction of 2c with cyanoacetyl hydrazide
resulted in the formation of N0-((2-chloroquinolin-3-yl) methy-
lene)-2-cyanoacetohydrazide which reacted with acetyl acetone in
refluxed ethanol to afford 3c (Scheme 1).
highly intense sharp singlets at
d
2.25e2.32 ppm were detected, indicating the presence of six alkyl
protons of two CH3 substituents. Also the corresponding broad
signal of NH2 was absent.
Compound 6 was prepared by the reaction of 1-amino-4,6-
dimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile (1) with phe-
nacyl bromide in refluxing ethanol yielding 6 as a sole product
based on TLC [29e31], via intermediates 5 and 5A as described in
Scheme 2. Compound 6 was obtained irrespective if one or 2
equivalents of 1 were being used.
The structure of compounds 3aeh was investigated qualita-
tively by elemental and spectral analysis. IR spectra of 3aeh
exhibited
a
carbonyl absorption band in the region
1670e1680 cmꢀ1 in addition to the absorption bands C]N in the
region 1632e1625 cmꢀ1 and the absorption band of NH2 was
absent. Their corresponding 1H NMR spectra showed singlet signal
Spectroscopic data (IR, 1H NMR, MS) and elemental analysis of
compound 6 confirmed its structure. The elemental analysis and
mass spectrum of the product proved that the reaction proceeded
Scheme 2. Synthesis of ethane-1,2-diaminopyridine. Reagents and conditions: phenacyl bromide (5 mmol), absolute ethanol, reflux, 7 h, crystallization from EtOH/DMF, 77% yield.

R.E. Khidre et al. / European Journal of Medicinal Chemistry 46 (2011) 5057e5064
5059
Scheme 3. Synthesis of N-2-oxo-pyridinyl phthalimide, hydrazides, urea, and thiourea derivatives. Reagents and conditions: A) absolute ethanol, glacial acetic acid (1 mL), reflux,
5e9 h, 70e72% yield; B) aromatic ester (10 mmol), absolute ethanol, reflux, 7e8 h, 65e75% yield; C) phenyl isocyanate or phenyl isothiocyanate (10 mmol), dioxane (30 mL), drops
of triethylamine, 6e8 h, 66e68% yield.
in 2:1 M ratio (1: phenacyl bromide). 1H NMR of 6 showed singlet
signal corresponding to two protons at 6.36 ppm for C5eH and
000106) and Bacillus subtilis (RCMB 000107) (as Gram positive
bacteria) and Pseudomonas aeruginoca (RCMB 000102), Escherichia
coli (RCMB 000103) (as Gram negative bacteria). Standard anti-
biotics, penicillin G and streptomycin were used as standard
antibiotics against Gram positive and Gram negative bacteria.
Compounds 1, 3a, 3f, 3g, 3h, 6, 8a, 8b, 10a, 10b, 11a, and 11b
possessed good anti-microbial activity against S. aureus and B.
subtilis (Table 1). Compounds 8a and 8b were the most effective
against S. aureus with zones of inhibition 24.4 and 26.4 respec-
tively. Also the same compounds (8a and 8b) showed the highest
activity against B. subtilis with zones of inhibition 25.4 and 26.4
respectively. Compounds 1, 3f, 3g, 3h, 6, 8a, 8b, 10a, and 11a, were
effective against E. coli and only compounds 1 and 3b showed
activity against P. aeruginoca. It is obvious that phthalimide
derivatives (8a and 8b) exhibited good anti-microbial activity
against Gram positive and Gram negative bacteria.
0
C5 eH present in the two pyridine rings. Two singlet protons signals
at 9.21 and 10.39 ppm were detected corresponding to the two NH
groups.
Treatment of 1 with molar quantity of phthalic anhydrides 7a or
tetrabromophthalic anhydride 7b in absolute ethanol containing few
drops of glacial acetic acid at reflux temperature, phthalimide
derivatives 8a and 8bwere obtained in 72 and 70% yield, respectively.
1-amino-4,6-dimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile (1)
was reacted with aryl esters 9a,b namely, e.g. ethyl 4-(benzofuran-2-
yl)-2,4-dioxobutanoate 9a or ethyl 3-amino-4-(4-methoxyphenyl)-
6-(thiophen-2-yl)thieno[2,3-b]pyridine-2-carboxylate 9b in abso-
lute ethanol at reflux temperature to afford the corresponding
hydrazides 10a and 10b, respectively in 75 and 65% yield. The reac-
tion of 1 with phenyl isocyanate or phenyl isothiocyanate in refluxing
DMF afforded substituted urea 11a or thiourea 11b as sole products
respectively (Scheme 3).
3.2. Antifungal activity
The Structures of compounds 8, 10, and 11 were established
through, spectroscopic and elemental analyses data. The IR spectra
of compound 11a for example displayed a broad signal band at
3395 cmꢀ1 due to 2NH absorptions. Additionally the proton signal
in 1H NMR spectra of these groups were observed at 8.98 and
9.45 ppm, respectively.
The limited number of available safe antifungal agents is the
driving force to search for new candidates. The promising anti-
bacterial activity of the tested compounds has encouraged us to test
these compounds against four different pathogenic fungi. The
tested fungi were Aspergillus fumigatus (RCMB 002003), Geotrichum
candidum (RCMB 052006), Candida albicans (RCMB 005002), Syn-
cephalastrum racemosum (RCMB 005003). Itraconazole and clo-
trimazole were used as standard antifungal agents (Table 2). In
general, all the compounds exhibited low to moderate antifungal
activity except compounds 8a and 8b which were effective against
three different fungi. The anti-microbial activity of this class of
compounds has been confirmed by other research groups [32e34].
It was proved that other phthalimide derivatives as phthalimido
3. Pharmacological evaluation
3.1. Antibacterial activity
Antibacterial activity of the synthesized compounds was tested
using agar well diffusion method. The activity of the tested
samples was studied against the Staphylococcus aureus (RCMB

5060
R.E. Khidre et al. / European Journal of Medicinal Chemistry 46 (2011) 5057e5064
Table 1
Antibacterial activity of compounds 1; 3a-h; 8a,b; 10a,b; and 11a,b.a,b,c
Compound
Gram positive bacteria
Gram negative bacteria
Staphylococcus aureus
Bacillus subtilis
(RCMB 000107)
Pseudomonas aeruginosa
(RCMB 000102)
Escherichia coli
(RCMB 000103)
(RCMB 000106)d
1
3a
3b
3c
14 ꢁ 0.5
14.9 ꢁ 0.03
14 ꢁ 0.5
17 ꢁ 0.5
15.2 ꢁ 0.04
NA
21.4 ꢁ 0.08
22.8 ꢁ 0.1
NA
NA
NAe
14 ꢁ 1.52
NA
NA
NA
NA
3d
NA
NA
NA
NA
3e
NA
NA
NA
NA
3f
3g
3h
6
8a
8b
10a
10b
11a
11b
Penicillin G
Streptomycin
18.6 ꢁ 0.01
23.2 ꢁ 0.01
21.2 ꢁ 0.02
15 ꢁ 0.08
24.4 ꢁ 0.5
26.4 ꢁ 0.2
20.4 ꢁ 0.08
13 ꢁ 0.10
7.2 ꢁ 0.08
15 ꢁ 0.08
29.48 ꢁ 0.82
25 ꢁ 0. 20
17.3 ꢁ 0.03
24.3 ꢁ 0.03
23.2 ꢁ 0.04
13.5 ꢁ 0.2
25.4 ꢁ 0.1
26.4 ꢁ 0.1
21.8 ꢁ 0.1
14.2 ꢁ 0.08
10.4 ꢁ 0.5
13.5 ꢁ 0.2
32.56 ꢁ 0.56
29 ꢁ 0.4
NA
NA
NA
NA
NA
NA
NA
NA
9.3 ꢁ 0.04
11.2 ꢁ 0.01
11.5 ꢁ 0.02
11.5 ꢁ 0.08
10.8 ꢁ 0.10
12.6 ꢁ 0.12
7.4 ꢁ 0.10
NA
NA
NA
11.4 ꢁ 0.50
NA
28.32 ꢁ 0.10
33.56 ꢁ 0.78
25 ꢁ 0.30
24 ꢁ 0.10
a
Mean zone of inhibition in mm ꢁ standard deviation beyond well diameter (6 mm) produced on a range of environmental and clinically pathogenic microorganisms using
(10 mg/mL) concentration of tested samples. The concentration used for the standard antibiotic was (30
m
g/mL).
b
The test was done using the diffusion agar technique. Well diameter: 6.0 mm (100
Data are expressed in the form of mean ꢁ SD.
mL was tested).
c
d
e
RCMB: Regional Center For Mycology And Biotechnology Culture Collection.
NA: No activity.
phosphor esters exhibited also antibacterial and antifungal
activity [22].
withdrawing groups on the pyridine ring attached to the phthali-
mide moiety. This finding is supported by previous studies sug-
gesting the positive role of electron withdrawing groups on the
biological activity of phthalimide derivatives [37,38].
Despite phthalimide anti-microbial activity, their cytotoxic
activity was generally low and extremely restricted to certain
structures with specific heterocyclic rings attached to the phthali-
mide moiety [39,40] or they were totally ineffective as cytotoxic
agents [41]. Even compounds with two phthalimide derivatives
were also ineffective as cytotoxic agents [42]. The reported anti-
microbial activity accompanied with the lack of measurable cyto-
toxic activity, indicates that phthalimide derivatives act as anti-
The presence of intact phthalimide ring is important to the
biological activity as opining of the phthalimide ring results in
profound decrease in the biological activity. Also it is obvious from
our anti-microbial data that compound 8b showed slightly higher
anti-microbial activity compared to 8a which can be correlated to
the presence of bromine substitutions. Several studies have sug-
gested the beneficial effect of bromine substitution as important
factor for increasing cellular permeability of many drug candidates
[35,36]. The high anti-microbial activity of the prepared phthali-
mide can be also correlated to the substitution of electron
Table 2
Antifungal activity of compounds 1; 3a-h; 8a,b; 10a,b; and 11a,b.a,b,c
Compounds
Fungi
Aspergillus fumigatus
Geotrichum candidum
(RCMB 052006)
Candida albicans
(RCMB 005002)
Syncephalastrum racemosum
(RCMB 005003)
(RCMB 002003)d
1
NAe
NA
NA
NA
3a
NA
NA
NA
NA
3b
3c
3d
3e
3f
3g
3h
6
11 ꢁ 0.2
13 ꢁ 0.05
12.4 ꢁ 0.1
13.2 ꢁ 0.1
11.5 ꢁ 0.1
13.4 ꢁ 0.04
18.4 ꢁ 0.50
16.5 ꢁ 0.04
12 ꢁ 0.05
21.4 ꢁ 0.04
23.5 ꢁ 0.20
NA
12 ꢁ 0.08
10.2 ꢁ 0.05
12.4 ꢁ 0.05
13.2 ꢁ 0.02
11.4 ꢁ 0.03
15.4 ꢁ 0.1
15.5 ꢁ 0.02
11 ꢁ 0.08
18.2 ꢁ 0.03
20.2 ꢁ 0.05
NA
NA
NA
NA
NA
NA
NA
NA
NA
13.3 ꢁ 0.09
14.5 ꢁ 0.05
10.3 ꢁ 0.04
11.2 ꢁ 0.01
15.2 ꢁ 0.08
14.2 ꢁ 0.02
10 ꢁ 0.20
19.2 ꢁ 0.03
22.5 ꢁ 0.02
NA
8a
8b
10a
NA
NA
NA
10b
11a
11b
Itraconazole
Clotrimazole
11.1 ꢁ 0.01
9.2 ꢁ 0.08
10.2 ꢁ 0.2
28 ꢁ 0.05
26 ꢁ 0.10
14 ꢁ 0.08
10.4 ꢁ 0.5
12 ꢁ 0.05
27 ꢁ 0.10
23 ꢁ 0.30
10 ꢁ 0.02
7.4 ꢁ 0.1
11 ꢁ 0.08
26 ꢁ 0.02
18 ꢁ 0.1
NA
NA
NA
22 ꢁ 0.09
20 ꢁ 0.2
a
Mean zone of inhibition in mm ꢁ standard deviation beyond well diameter (6 mm) produced on a range of environmental and clinically pathogenic microorganisms using
(10 mg/mL) concentration of tested samples. The concentration used for the standard antibiotic was (30
m
g/mL).
b
The test was done using the diffusion agar technique. Well diameter: 6.0 mm (100
Data are expressed in the form of mean ꢁ SD.
mL was tested).
c
d
e
RCMB: Regional Center For Mycology And Biotechnology Culture Collection.
NA: No activity.

R.E. Khidre et al. / European Journal of Medicinal Chemistry 46 (2011) 5057e5064
5061
microbial agents through a different mechanism other than cyto-
toxicity. The world wide increase in anti-microbial drug resistance
and the promising anti-microbial activity of these phthalimide
derivatives are encouraging factors to investigate the possibility of
their utilization as future anti-microbial agents.
ethanol, and crystallized from appropriate solvent to produces
3aeh in high yields.
5.1.4. 1-[(4-fluoro-benzylidene)-amino]-4,6-dimethyl-2-oxo-1,2-
dihydro-pyridine-3-carbonitrile (3a)
Reaction time 5 h, yellow crystals, mp 191e193 ꢂC (EtOH), yield
90%. IR (KBr, cmꢀ1): nmax 3025 (CH, aryl), 2200 (CN), 1670 (C]O,
4. Conclusion
amide), 1630 (C]N); 1H NMR (DMSO-d6) ppm:
d 2.29 (s, 3H, CH3),
The new ring system compounds prepared in our study seems to
have interesting biological activity. Furthermore, the present
investigation offers rapid and effective new procedures for the
synthesis of the polycondensed new heterocyclic ring systems as
hydrazide hydrazone, amino pyrazol, tetrazoloquinolin, pyridinyl
phthalimide, phenyl (thio) urea-pyridine derivatives. The feasibility
of the synthetic procedures and the excellent yield of the prepared
compounds are the main advantages for the developed protocol.
The antibacterial and antifungal activities of the prepared
compounds were evaluated showing moderate to good activities.
Phthalimide derivatives 8a and 8b exhibited the highest antibac-
terial and antifungal activities comparable to standard antibiotics.
2.32 (s, 3H, CH3), 6.37 (s, 1H, C5eH, pyridine), 7.35 (2d, 2H,
J ¼ 8.62 Hz, 4-F-phenyl), 7.96 (2d, 2H, J ¼ 8.64 Hz, 4-F-phenyl), 8.55
(s, 1H, CH]Ne). EI-MS: m/z (%) 271 (Mþ þ2, 32.60), 270 (Mþ þ1,
44.50), 269 (Mþ, 75.10), 249 (Mþ
ꢀ
F, 100). Anal.Calc. for
C15H12FN3O (269.27): C, 66.91; H, 4.49; F, 7.06; N, 15.60. Found: C,
66.85; H, 4.42; F, 7.10; N, 15.55.
5.1.5. 4,6-dimethyl-2-oxo-1-[(thiophen-2-ylmethylene)-amino]-
1,2-dihydro-pyridine-3-carbonitrile (3b)
Reaction time 5 h, yellowish crystals, mp 210e212 ꢂC (MeOH),
yields 88%. IR (KBr, cmꢀ1): nmax 3030 (CH, aryl), 2205 (CN), 1674
(C]O, amide), 1627 (C]N); 1H NMR (DMSO-d6) ppm:
d 2.22 (s, 3H,
CH3), 2.27 (s, 3H, CH3), 2.31 (s, 3H, CH3), 6.35 (s,1H, C5eH, pyridine),
7.25 (t, 1H, J ¼ 7.0 Hz, thiophene), 7.74 (d, 1H, J ¼ 6.95 Hz, thiophen),
7.94 (d, 1H, J ¼ 7.1 Hz, thiophene), 8.44 (s, 1H, CH]Ne); EI-MS: m/z
(%) 259 (Mþ þ2, 30.20), 258 (Mþ þ1, 40.60), 257 (Mþ,78.30).
Anal.Calc. for C13H11N3OS (257.31): C, 60.68; H, 4.31; N, 16.33; S,
12.46. Found: C, 60.61; H, 4.25; N, 16.22; S, 12.40.
5. Experimental
5.1. Chemistry
5.1.1. General procedures
All melting points were taken on Electrothermal IA 9000 series
digital melting point apparatus. Elemental analytical data (in
accordance with the calculated values) were obtained from the
microanalytical unit, National Research Centre, Dokki, Giza, Egypt.
The IR spectra (KBr) were recorded on a Shimadzu CVT-04 spec-
trophotometer. The 1H-NMR spectra were recorded at 270 MHz on
a Varian EM-360 spectrometer using tetramethylsilane (TMS) as an
5.1.6. 1-[(2-chloro-quinolin-3-ylmethylene)-amino]-4,6-dimethyl-
2-oxo-1,2-dihydro-pyridine-3-carbonitrile (3c)
Reaction times 5 h, yellow crystals, mp 295e297 ꢂC (EtOH), yield
85%. IR (KBr, cmꢀ1): nmax 3040 (CH, aryl), 2210 (CN),1675 (C]O,
amide), 1628 (C]N); 1H NMR (DMSO-d6) ppm:
d 2.23 (s, 3H, CH3),
2.26 (s, 3H, CH3), 6.36 (s, 1H, C5eH, pyridine), 7.75e8.43 (m, 5H,
quinoline), 8.54 (s, 1H, CH]Ne); EI-MS: m/z (%) 338 (Mþ þ 2,
29.40%), 337 (Mþ þ 1, 30.10%), 336 (Mþ, 80.50%). Anal.Calc. for
C18H13ClN4O (336.78): C, 64.19; H, 3.89; Cl, 10.53; N, 16.64; Found:
C, 64.11; H, 3.80; Cl, 10.43; N, 16.60.
internal standard. Chemical shift (d) values are given in parts per
million. The mass spectra were determined using a Varian MAT CH-
5 spectrometer (70 eV). 2-chloroquinoline-3-carbaldehyde 2c [43],
2-chloro-6-methyl quinoline-3-carbaldehyde 2d [43], 5-chloro-1-
phenyl-1H-pyrazole-4-carbaldehyde 2e [44], tetrazolo[1,5-a]quin-
oline-4-carbaldehyde 2f [45], 7-Methyltetrazolo[1,5-a]quinoline-4-
carbaldehyde 2g [46], 3-(benzofuran-2-yl)-1-phenyl-1H-pyrazole-
4-carbaldehyde 2h [47], ethyl 4-(benzofuran-2-yl)-2,4-dioxobut
anoate 9a [48], and ethyl 3-amino-4-(4-methoxyphenyl)-6-(thio-
phen-2-yl)thieno[2,3-b]pyridine-2-carboxylate 9b [49] were
prepared according to the reported procedures.
5.1.7. 1-[(2-chloro-6-methyl quinolin-3-ylmethylene)-amino]-4,6-
dimethyl-2-oxo-1,2-dihydro-pyridine-3-carbonitrile (3d)
Reaction times 8 h, brownish powder, mp 260e262 ꢂC (EtOH),
yield 83%. IR (KBr, cmꢀ1): nmax 3035 (CH, aryl), 2220 (CN), 1678 (C]
O, amide), 1632 (C]N); 1H NMR (DMSO-d6) ppm:
d 2.24 (s, 3H,
CH3), 2.28 (s, 3H, CH3), 2.36 (s, 3H, CH3), 6.34 (s,1H, C5eH, pyridine),
7.55e7.78 (m, 4H, quinoline), 8.22 (s, 1H, 1H, CH]Ne); EI-MS: m/z
(%) 352 (Mþ þ 2, 26.20%), 351 (Mþþ1, 22.30%), 350 (Mþ,70.40%).
Anal.Calc. for C19H15ClN4O (350.80): C, 65.05; H, 4.31; Cl, 10.11; N,
15.97; Found: C, 65.15; H, 4.35; Cl, 10.01; N, 15.90.
5.1.2. N0e((2-chloroquinolin-3-yl) methylene)-2-
cyanoacetohydrazide (4c)
To a solution of 2-cyanoacetohydrazide (0.99 g, 10 mmol) in
absolute ethanol (30 mL) 2-chloroquinoline-3-carbaldehyde 1
(1.91 g, 10 mmol) was added in the presence of two drops of glacial
acetic acid. The reaction mixture was heated under reflux for 1 h
then left to cool to room temperature. The solid product formed
upon pouring onto ice/water was collected by filtration.
IR (KBr) nmax/cmꢀ1 1620 (C]O), 2185 (CN), 3195 (NH); 1H NMR
5.1.8. 1-[(5-chloro-3-methyl-1-phenyl-1H-pyrazol-4-ylmethylene)-
amino]-4,6-dimethyl-2-oxo-1,2-dihydro-pyridine-3-carbonitrile (3e)
Reaction times 7 h, yellowish crystals, mp 212e214 ꢂC (EtOH),
yield 80%. IR (KBr, cmꢀ1): nmax 3033 (CH, aryl), 2218 (CN), 1679 (C]
O, amide), 1630 (C]N); 1H NMR (DMSO-d6) ppm:
d 2.21 (s, 3H,
(DMSO-d6)
d
3.98 (s, 2H, CH2), 7.28e7.92 (m, 5H, AreH), 9.02(s, 1H,
CH3), 2.25 (s, 3H, CH3), 2.74 (s, 3H, CH3), 6.33 (s,1H, C5eH, pyridine),
7.31e7.55 (m, 5H, phenyl), 8.18 (s,1H, CH]Ne); EI-MS: m/z (%) 367
(Mþ þ 2, 36.20), 366 (Mþ þ 1, 42.10), 365 (Mþ, 78.50). Anal.Calc. for
C19H16ClN5O (365.82): C, 62.38; H, 4.41; Cl, 9.69; N, 19.14. Found: C,
62.30; H, 4.36; Cl, 9.55; N, 19.10.
CH]N), 12.17(s, H, NH, D2O-exchangeable); MS m/z (%): 272 (Mþ,
12), 63(100).
5.1.3. General procedures for the synthesis of hydrazide hydrazone
3aeh
A mixture of 1 (1.63 g, 10 mmol) and the appropriate aromatic
aldehyde derivatives 2aeh (10 mmol) in mixture of absolute
ethanol (30 mL) containing few drops of glacial acetic acid (1 mL)
was refluxed till the solid was formed, The reaction mixture was
allowed to cool to room temperature, filtered off, washed with
5.1.9. 4,6-Dimethyl-2-oxo-1-[(1,2,3,4-tetrazolo[1,5-a]quinolin-6-
ylmethylene)-amino]-1,2-dihydro-pyridine-3-carbonitrile (3f)
Reaction times 6 h, yellow crystals, mp 275e277 ꢂC (dioxane),
yield 82%. IR (KBr, cmꢀ1): nmax 3037 (CH, aryl), 2215 (CN), 1680 (C]
O, amide), 1630 (C]N); 1H NMR (DMSO-d6) ppm:
d 2.20 (s, 3H,

5062
R.E. Khidre et al. / European Journal of Medicinal Chemistry 46 (2011) 5057e5064
CH3), 2.27 (s, 3H, CH3) 6.37 (s,1H, C5eH, pyridine), 7.42e7.71(m, 5H,
quinoline), 8.15 (s, 1H, CH]Ne); EI-MS: m/z (%) 345 (Mþ þ 2,
30.10), 344 (Mþ þ 1, 40.30), 343 (Mþ, 75.20). Anal.Calc. for
C18H13N7O (343.34): C, 62.97; H, 3.82; N, 28.56; Found: C, 62.90; H,
3.75; N, 28.49.
(293.28): C, 65.53; H, 3.78; N, 14.33; Found: C, 65.50; H, 3.71; N,
14.30.
5.1.15. 4,6-dimethyl-2-oxo-1-(4,5,6,7-tetrabromo-1,3-
dioxoisoindolin-2-yl)-1,2-dihydropyridine-3-carbonitrile (8b)
Reaction times 9 h, yellow powder, mp 225e227 ꢂC (DMF), yield
70%. IR (KBr, cmꢀ1): nmax 3044 (CH, aryl), 2218 (CN), 1715, 1696
5.1.10. 4,6-Dimethyl-2-oxo-1-[(9-methyl-1,2,3,4-tetrazolo[1,5-a]
quinolin-6-ylmethylene)-amino]-1,2-dihydro-pyridine-3-
carbonitrile (3g)
(C(1,3) ¼ O), 1679 (C]O, amide); 1H NMR (DMSO-d6) ppm:
d 2.22
(s, 3H, CH3), 2.28 (s, 3H, CH3); 6.37 (s, 1H, C5eH, pyridine). EI-MS:
m/z (%) 610 (Mþ þ 2, 30.73), 609 (Mþ þ1, 55.20), 608 (Mþ, 83.60).
Anal.Calc. for C16H7Br4N3O3 (608.86): C, 31.56; H, 1.16; Br, 52.49; N,
6.90. Found: C, 31.50; H, 1.12; Br, 52.42; N, 6.85.
Reaction times 8 h, yellowish brown crystals, mp 310e312 ꢂC
(DMF), yield 79%. IR (KBr, cmꢀ1): nmax 3030 (CH, aryl), 2216 (CN),
1677 (C]O, amide), 1628 (C]N); 1H NMR (DMSO-d6) ppm:
d 2.22
(s, 3H, CH3), 2.27 (s, 3H, CH3), 2.34 (s, 3H, CH3), 6.35 (s, 1H, C5eH,
pyridine), 7.35e7.55 (m, 4H, quinoline), 8.30 (s, 1H, CH]Ne); EI-
MS: m/z (%) 359 (Mþ þ 2, 28.40), 358 (Mþ þ 1, 47.30), 357 (Mþ,
82.30). Anal.Calc. for C19H15N7O (357.37): C, 63.86; H, 4.23; N, 27.44.
Found: C, 63.93; H, 4.28; N, 27.51.
5.1.16. General procedures for the synthesis of hydrazides 10a,b
A mixture of 1 (1.63 g, 10 mmol) and ethyl 4-(benzofuran-2-yl)-
2,4-dioxobutanoate 9a or ethyl 3-amino-4-(4-methoxyphenyl)-6-
phenylthieno[2,3-b]pyridine-2-carboxylate 9b (10 mmol) in abso-
lute ethanol (30 mL) containing few drops of glacial acetic acid
(1 mL) was refluxed for w7 h (TLC), The reaction mixture was
allowed to cool at room temperature, filtered off, washed with
ethanol, and crystallized from appropriate solvent to produces 10a
and 10b, respectively.
5.1.11. 1-[(3-benzofuran-2-yl-1-phenyl-1H-pyrazol-4-
ylmethylene)-amino]-4,6-dimethyl-2-oxo-1,2-dihydro-pyridine-3-
carbonitrile (3h)
Reaction times 6 h, yellowish brown crystals, mp 255e257 ꢂC
(DMF), yield 75%. IR (KBr, cmꢀ1): nmax 3029 (CH, aryl), 2210 (CN),
1675 (C]O, amide), 1625 (C]N); 1H NMR (DMSO-d6) ppm:
d
2.21
5.1.17. 4-(benzofuran-2-yl)-N-(3-cyano-4,6-dimethyl-2-
(s, 3H, CH3), 2.28 (s, 3H, CH3), 6.36 (s, 1H, C5eH, pyridine), 7.31e7.94
(m, 9H, H-Het & Ar), 8.12 (s,1H, CH]Ne); EI-MS: m/z (%) 435
(Mþ þ 2, 25.30), 434 (Mþ þ 1, 40.20), 433 (Mþ, 80.10). Anal.Calc. for
C26H19N5O2 (433.46): C, 72.04; H, 4.42; N, 16.16. Found: C, 72.12; H,
4.46; N, 16.12.
oxopyridin-1(2H)-yl)-2,4-dioxobutanamide (10a)
Reaction times 8 h, white powder, mp 149e151 ꢂC (MeOH), yield
75%. IR (KBr, cmꢀ1): nmax 3420 (br., NH), 3035 (CH, aryl), 2218 (CN),
1735, 1720 (2C]O), 1685, 1674 (2C]O, amide). 1H NMR (DMSO-d6)
ppm: d 2.22 (s, 3H, CH3), 2.28 (s, 3H, CH3), 3.82 (s, 2H, CH2), 6.35 (s,
1H, C5eH, pyridine), 7.22e7.89 (m, 5H, benzofurane), 9.20 (br., 1H,
NH, D2O exch.). EI-MS: m/z (%) 379 (Mþ þ 2, 22.10), 378 (Mþ þ 1,
30.20), 377 (Mþ, 76.60). Anal.Calc. for C20H15N3O5 (377.35): C,
63.66; H, 4.01; N, 11.14; Found: C, 63.72; H, 4.11; N, 11.18.
5.1.12. Synthesis of (Z)-1-(2-(3-cyano-4,6-dimethyl-2-oxopyridin-
1(2H)-ylamino)-1-phenylvinylamino)-4,6-dimethyl-2-oxo-1,2-
dihydropyridine-3-carbonitrile (6)
To a solution hydrazides 1 (1.63 g, 10 mmol) in ethanol (50 mL),
phenacyl bromide (0.99 g, 5 mmol) was added. The reaction was
refluxed for 7 h, then cool to room temperature. The formed solid
was filtered off, washed with ethanol and recrystallized from EtOH/
DMF to afford compounds 6. Yellow crystals, yield 77%, mp
235e236 ꢂC. IR (cmꢀ1, KBr): nmax 3320, 3313(2NH), 2218, 2212
5.1.18. 3-amino-N-(3-cyano-4,6-dimethyl-2-oxopyridin-1(2H)-yl)-
4-(4-methoxyphenyl)-6-(thiophen-2-yl)thieno[2,3-b]pyridine-2-
carboxamide (10b)
Reaction time 7 h, yellow powder, mp 137e139 ꢂC (dioxane),
yields 65%. IR (KBr, cmꢀ1): nmax: 3440 (br., NH, NH2), 3032 (CH,
aryl), 2221(CN), 1684, 1676 (2C]O, amide). 1H NMR (DMSO-d6)
(2CN), 1675, 1669 (2C]O, amide); 1H NMR (DMSO-d6) ppm:
d 2.18
(s, 3H, CH3), 2.26 (s, 3H, CH3), 2.37 (s, 3H, CH3), 2.46 (s, 3H, CH3),
5.93 (s,1H, C]CHe), 6.36 (s, 2H, C5,5`-H pyridine), 7.63e7.72 (m, 5H,
H-Ph), 9.21 (s, 1H, D2O exchangeable, NH), 10.39 (s, 1H, D2O
exchangeable, NH). EI-MS: m/z (%) 428 (Mþ þ 2, 10), 427 (Mþ þ 1,
15), 426 (Mþ, 60). Anal.Calc. for C24H22N6O2 (426.47): C, 67.59; H,
5.20; N, 19.71. Found: C, 67.51; H, 5.08; N, 19.66.
ppm: d 2.21 (s, 3H, CH3), 2.28 (s, 3H, CH3), 3.74 (s, 3H, OCH3), 6.33 (s,
1H, C5eH, pyridine), 7.19e8.53 (m, 9H, H-Het & Ar), 6.99. (br., 2H,
NH2, D2O exch.), 11.51 (br., H, NH, D2O exch.); EI-MS: m/z (%) 529
(Mþ þ 2, 12.40), 528 (Mþ þ 1, 22.60), 527 (Mþ, 79.90). Anal.Calc. for
C27H21N5O3S2 (527.62): C, 61.46; H, 4.01; N, 13.27; S, 12.15; Found:
C, 61.39; H, 3.93; N, 13.18; S, 11.99.
5.1.13. General procedures for the synthesis of N-2-oxo-pyridinyl
phthalimide 8a,b
5.1.19. General procedures for the synthesis of 1-(3-cyano-4,6-
dimethyl-2-oxopyridin-1(2H) -yl)-3-phenyl(thio)urea (11a,b)
A mixture of compound 1(1.63 g, 10 mmol), phenyl isocyanate or
phenyl isothiocyanate 8b (10 mmol), in dioxane (30 mL) containing
few drops of triethylamine was refluxed for w7 h (TLC). The solu-
tion was evaporated under reduced pressure to z1/3 of its volume.
The separated precipitate was filtered off, washed with ethanol,
dried, and crystallized from dioxane to afford 12a and 12b,
respectively.
A mixture of 1 (1.63 g, 10 mmol) and phthalic anhydride 7a or
tetrabromophthalic anhydride 7b (10 mmol) in mixture of absolute
ethanol (30 mL) containing few drops of glacial acetic acid (1 mL)
was refluxed for w10 h (TLC), The reaction mixture was allowed to
cool at room temperature, filtered off, washed with ethanol, and
crystallized from appropriate solvent to produces 8a and 8b
respectively.
5.1.14. 1-(1, 3-dioxo-1,3-dihydro-isoindol-2-yl)-4,6-dimethyl-2-
oxo-1,2-dihydro-pyridine-3-carbonitrile (8a)
5.1.20. 1-(3-Cyano-4,6-dimethyl-2-oxopyridin-1(2H)-yl)-3-
phenylurea (11a)
Reaction times 5 h, yellowish brown powder, mp 155e157 ꢂC
(DMF), yield 72%. IR (KBr, cmꢀ1): nmax 3038 (CH, aryl), 2208 (CN),
1710, 1695 (C(1,3) ¼ O), 1677 (C]O, amide); 1H NMR (DMSO-d6)
Reaction time 6 h, yellow powder, mp 345e347 ꢂC (dioxane),
yields 66%. IR (KBr, cmꢀ1): nmax: 3395 (br., 2NH), 3030 (CH, aryl),
2216 (CN), 1681, 1672 (2C]O, amide); 1H NMR (DMSO-d6) ppm:
ppm:
d
2.23 (s, 3H, CH3), 2.28 (s, 3H, CH3), 6.35 (s, 1H, C5eH, pyri-
d 2.23 (s, 3H, CH3), 2.28 (s, 3H, CH3), 6.35 (s,1H, pyridine H-5),
dine), 7.45e7.83 (m, 4H, H-Het). EI-MS: m/z (%) 295 (Mþ þ 2, 20.50),
7.24e7.64 (m, 5H, phenyl), 8.98 (br., 1H, NH, D2O exch.), 9.45 (br.,
294 (Mþ þ 1, 45.10), 293 (Mþ, 88.20). Anal.Calc. for C16H11N3O3
1H, NH, D2O exch.). EI-MS: m/z (%) 284 (Mþ þ 2, 27.50), 283 (Mþ þ 1,

R.E. Khidre et al. / European Journal of Medicinal Chemistry 46 (2011) 5057e5064
5063
16.80), 282 (Mþ, 70.10). Anal.Calc. for C15H14N4O2 (282.30): C,
63.82; H, 5.00; N, 19.85; Found: C, 63.76; H, 4.48; N, 19.80.
culture is properly adsorbed on the surface of Sabouraud dextrose
agar plates. Small wells of size (4 mm ꢃ 2 mm) were cut into the
plates with the help of well cutter and bottom of the wells were
sealed with 0.8% soft agar to prevent the flow of test sample at the
5.1.21. 1-(3-Cyano-4,6-dimethyl-2-oxo-pyridin-1(2H)-yl)-3-
phenylthiourea(11b)
bottom of the well. 100 mL of the tested samples (10 mg/mL) was
Reaction time 8 h, yellowish brown powder, mp 205e207 ꢂC
(dioxane), yields 68%. IR (KBr, cmꢀ1): nmax: 3390 (br., 2NH), 3032
(CH, aryl), 2218 (CN), 1675 (C]O, amide 1355 (C]S). 1H NMR
loaded into the wells of the plates. All compounds was prepared in
dimethyl sulfoxide (DMSO), DMSO was loaded as control. The
plates were kept for incubation at 30 ꢂC for 3e4 days and then the
plates were examined for the formation of inhibition zone. Each
inhibition zone was measured three times by caliper to get an
average value. The test was performed three times for each fungus.
(DMSO-d6) ppm:
d 2.22 (s, 3H, CH3), 2.30 (s, 3H, CH3), 6.34 (s, 1H,
pyridine H-5), 7.32e7.69 (m, 5H, phenyl), 8.95 (br., 1H, NH, D2O
exch.), 8.55 (br., 1H, NH, D2O exch.). EI-MS: m/z (%) 300 (Mþ þ 2,
34.40), 299 (Mþ þ1, 10.70), 298 (Mþ, 68.50). Anal.Calc. for
C15H14N4OS (298.36): C, 60.38; H, 4.73; N, 18.78; S, 10.75. Found: C,
60.31; H, 4.70; N, 18.72; S, 10.68.
References
[1] S. Rallas, N. Gulerman, H. Erdeniz, Farmaco 57 (2002) 171e174.
[2] A. Gursoy, N. Terzioglu, G. Ouch, Eur. J. Med. Chem. 32 (1997) 753e757.
[3] N. Rashed, A.M. El Massry, E.-S.H. El Ashry, A. Amer, H. Zimmer, J. Heterocycl,
Chem 27 (1990) 691e694.
5.2. Biology Experiments
This work has been done in, The Regional Center for Mycology and
Biotechnology, Al-Azhar University, Nasr City, Cairo, Egypt.
[4] S. Rollas, S.G. Kucukguzel, Molecules 12 (2007) 1910e1939.
ꢀ
[5] A. Imramovsky, S. Polanc, J. Vinsova, M. Kocevar, J. Jampitek, Z. Reckova,
J.A. Kaustova, Bioorg. Med. Chem. 15 (2007) 2551e2553.
[6] Y. Janin, Bioorg. Med. Chem. 15 (2007) 2479e2513.
[7] J.R. Dimmock, S.C. Vasishtha, J.P. Stables, Eur. J. Med. Chem. 35 (2000) 241e248.
[8] P.C. Lima, L.M. Lima, K.C. Silva, P.H. Leda, A.L.P. Miranda, C.A.M. Fraga,
J.E. Barreiro, Eur. J. Med. Chem. 35 (2000) 187e203.
[9] U. Salgin-Goksen, N. Gokham-Keleci, O. Gostal, Y. Koysal, E. Kilici, S. Isik,
G. Aktay, M. Ozalp, Bioorg. Med. Chem. 15 (2007) 5738e5751.
[10] R. Kalsi, M. Shrimali, T.N. Bhalla, J.P. Barthwal, Indian J. Pharm. Sci. 41 (2006)
353e359.
[11] G.A. Silva, L.M.M. Costa, F.C.F. Brito, A.L.P. Miranda, E.J. Barreiro, C.A.M. Fraga,
Bioorg. Med. Chem. 12 (2004) 3149e3158.
[12] L. Savini, L. Chiasserini, V. Travagli, C. Pellerano, E. Novellino, S. Consentino,
M.B. Pisano, Eur. J. Med. Chem. 39 (2004) 113e122.
[13] A. Bijev, Lett. Drug Design Discov. 3 (2006) 506e512.
[14] C. Loncle, J.M. Brunel, N. Vidal, M. Dherbomez, Y. Letourneux, Eur. J. Med.
Chem. 39 (2004) 1067e1071.
[15] M.T. Abdel-Aal, W.A. El-Sayed, E.H. El-Ashry, Arch. Pharm. Chem. Life Sci. 339
(2006) 656e663.
[16] J. Capilla, C. Serena, F. Javier, T. Ortoneda, J. Guarro, Antimicrobial. Agents.
Chemother. 47 (2003) 3976e3978.
[17] A. Walcourt, M. Loyevsky, D.B. Lovejoy, V.R. Gordeuk, D.R. Richardson, Int. J.
Biochem. Cell. Biol. 36 (2004) 401e407.
[18] S.A.M. El-Hawash, W.A.E. Abdel, M.A. El-Dewellawy, Arch. Pharm. Chem. Life
Sci. 339 (2006) 14e23.
[19] M.T. Cocco, C. Congiu, V. Lilliu, V. Onnis, Bioorg. Med. Chem. 14 (2005)
366e372.
[20] A. Dandia, V. Sehgal, P. Singh, Indian. J. Chem. 32B (1993) 1288e1291.
[21] M.J. Anne, O.M.M. Josephine, L.S. Derid Wo, Chem. Abstr. 129 (1998) 20833s.
[22] W.M. Abdou, R.E. Khidre, Monatsh. Chem. 141 (2010) 219e228.
[23] W.M. Abdou, M.D. Khidre, R.E. Khidre, Eur. J. Med. Chem. 44 (2009) 526e532.
[24] A.A. Abu-Hashem, M.A. Gouda, F.A. Badria, Eur. J. Med. Chem. 45 (2010)
1976e1981.
5.2.1. Antibacterial activity
Antibacterial activity was investigated using agar well diffusion
method. The activity of the tested samples was studied against the
S. aureus and B. subtilis (as Gram positive bacteria) and Pseudo-
monas aeruginosa, E. coli and Salmonella typhi (as Gram negative
bacteria). The solution of 10 mg/mL of each compound and stan-
dard drug in DMSO was prepared for using against the tested
bacteria. Centrifuged pellets of bacteria from a 24 h old culture
containing approximately 104e106 CFU (colony forming unit) per
mL were spread on the surface of nutrient agar (typetone 1%, yeast
extract 0.5%, NaCl 0.5%, agar 1%, 1000 mL of distilled water, pH 7.0)
which was autoclaved under 121 ꢂC for at least 20 min. Wells were
created in medium with the help of a sterile metallic bores and then
cooled down to 45 ꢂC. The activity was determined by measuring
the diameter of the inhibition zone (in mm). 100 mL of the tested
samples (10 mg/mL) were loaded into the wells of the plates. All
compounds was prepared in dimethyl sulfoxide (DMSO), DMSO
was loaded as control. The plates were kept for incubation at 37 ꢂC
for 24 h and then the plates were examined for the formation of
inhibition zone. Each inhibition zone was measured three times by
caliper to get an average value. The test was performed three times
for each bacterium culture.
5.2.2. Antifungal activity
[25] A.A. Abu-Hashem, M.F. El Shehry, F.A. Badria, Acta. Pharm. 60 (2010) 311e323.
[26] W. Ried, A. Meyer, DE 1189994 (1965); http://worldwide.espacenet.com/
numberSearch?locale¼en_EP.
Tested samples were screened separately in vitro for their anti-
fungal activity against various fungi viz. A. fumigatus, G. candidum,
C. albicans, S. racemosum, these species were isolated from the
infected organs of some patients on Sabouraud dextrose agar plates.
The culture of fungi was purified by single spore isolation tech-
nique. The antifungal activity was done by agar well diffusion
method according to the following procedure:
[27] W. Ried,A.Meyer, Chem. Ber. 90(1957) 2841e2848 Chem. Abstr. 52 (1958) 88076.
[28] S. Beckmann, E. Schefczik, US 5466812 (1995); http://worldwide.espacenet.
com/numberSearch?locale¼en_EP.
[29] H.A. Abdel-Aziz, B.F. Abdel-Wahab, F.A. Badria, Arch. Pharm. Chem. Life Sci.
343 (2010) 152e159.
[30] H.A. Abdel-Aziz, A.A.I. Mekawey, Eur. J. Med. Chem. 44 (2009) 4985e4997.
[31] H.A. Abdel-Aziz, A.A.I. Mekawey, K.M. Dawood, Eur. J. Med. Chem. 44 (2009)
3637e3644.
[32] M. Ahmedzade, A. Cukurovali, M. Koparir, J. Chem, Soc. Pak 25 (2003) 51e55.
[33] S. Sharma, C. Sharma, R. Dangi, G.L. Talesara, J. Ind, Counc. Chem. 26 (2009)
139e145.
[34] D. Bhambi, V.K. Salvi, A. Bapna, G. Pemawat, G.L. Talesara, J. Ind, Counc. Chem.
48 (2009) 697e704.
[35] C.L. Gentry, R.D. Egleton, T. Gillespie, T.J. Abbruscato, H.B. Bechowski,
V.J. Hruby, T.P. Davis, Peptides 20 (1999) 1229e1238.
[36] M.Z. Hernandes, S.M.T. Cavalcanti, D.R.M. Moreira, W.F. de Azevedo Junior,
A.C.L. Leite, Curr. Drug. Targets. 11 (2010) 1e12.
5.2.2.1. Sabouraud dextrose agar plates. A homogeneous mixture of
glucose-peptone-agar (40:10:15) was sterilized by autoclaving at
121 ꢂC and 15 lb/cm2 for 20 min. The sterilized solution (25 mL) was
poured in each sterilized Petri dish in laminar flow and left for
20 min to form the solidified sabouraud dextrose agar plate. These
plates were inverted and kept at 30 ꢂC in incubator to remove the
moisture and to check for any contamination.
[37] M.D.C. Neto, W.C.P. Filho, B.B. Neto, M.N. Ramos, J. Braz, Chem. Soc. 4 (1993)
139e142.
5.2.2.2. Antifungal assay. Fungal strain was grown in 5 mL Sabo-
uraud dextrose broth (glucose:peptone, 40:10) for 3e4 days to
achieve 105 CFU/mL cells. The fungal culture (0.1 mL) was spread
out uniformly on the sabouraud dextrose agar plates by sterilized
triangular folded glass rod. Plates were left for 5e10 min so that
[38] R. Pascale, A. Carocci, A. Catalano, G. Lentini, A. Spagnoletta, M.M. Cavalluzzi,
F. De Santis, A. De Palma, V. Scalera, C. Franchini, Bioorg. Med. Chem. 18
(2010) 5903e5914.
[39] T. Wang, Y.H. Zhang, H. Ji, Y.P. Chen, S.X. Peng, Chin. Chem. Lett. 19 (2008) 26e28.
[40] Y.J. Yang, Y.N. Yang, J.S. Jiang, Z.M. Feng, H.Y. Liu, X.D. Pan, P.C. Zhang, Chin.
Chem. Lett. 21 (2010) 902e904.

5064
R.E. Khidre et al. / European Journal of Medicinal Chemistry 46 (2011) 5057e5064
[41] S. Ojha, A. Bapna, G.L. Talesara, ARKIVOC xi (2008) 112e122.
[42] M. Szumilak, A. Szulawska-Mroczek, K. Koprowska, M. Stasiak, W. Lewgowd,
A. Stanczak, M. Czyz, Eur. J. Med. Chem. 45 (2010) 5744e5751.
[43] P.K. Kalita, B. Baruah, P.J. Bhuyan, Tetrahedron. Lett. 47 (2006) 7779e7782.
[44] P. Cmoch, L. Stefaniak, G.A. Webb, Magn. Reson. Chem. 35 (1997)
237e242.
[46] B. Datterl, N. Tröstner, D. Kucharski, W. Holzer, Molecules 15 (2010)
6106e6126.
[47] D.B.A. Kumar, G.K. Prakash, M.N. Kumary Aswam, B.P. Nandeshwarappa,
B.S. Sherigara, K.M. Mahadevan, Indian. J. Chem. 46B (2007) 336e343.
[48] B.F. Abdel-Wahab, H.A. Abdel-Aziz, E.M. Ahmed, Arch. Pharm. Chem. Life Sci.
341 (2008) 734e739.
[45] W.M. Abdou, R.E. Khidre, A.A. Shaddy, J. Heterocyclic Chem., in press, doi:10.
1002/jhet.968.
[49] E.A. Bakhite, A.E. Abdel-Rahman, O.S. Mohamed, E.A. Thabet, Phosphorus,
Sulfur Silicon Relat. Elem. 179 (2004) 1983e2006.