Quinoline derivatives bearing pyrazole moiety: Synthesis and biological evaluation as possible antibacterial and antifungal agents

Article abstract of DOI:10.1016/j.ejmech.2017.10.046

In an attempt for development of new antimicrobial agents, three series of quinoline derivatives bearing pyrazole moiety have been synthesized. The first series was synthesized through the synthesis of 4-(quinolin-2-yloxy)benzaldehyde and 4-(quinolin-2-yloxy)acetophenone and then treatment with ketone or aldehyde derivatives to afford the corresponding chalcones. Cyclization of the latter chalcones with hydrazine derivatives led to the formation of new pyrazoline derivatives. The second series was synthesized via the synthesis of 2-hydrazinylquinoline and then treatment with formylpyrazoles to afford the corresponding hydrazonyl pyrazole derivatives. The third series was synthesized through the treatment of 2-hydrazinylquinoline with ethoxyethylidene, dithioacetal and arylidene derivatives to afford the corresponding pyrazole derivatives. The synthesized compounds were evaluated for their expected antibacterial and antifungal activities; where, the majority of these compounds showed potent antibacterial and antifungal activities against the tested strains of bacteria and fungi. Pyrazole derivative 13b showed better results when compared with the reference drugs as revealed from their MIC values (0.12–0.98 μg/mL). The pyrazole derivative 13b showed fourfold potency of gentamycin in inhibiting the growth of S. flexneri (MIC 0.12 μg/mL). Also, compound 13b showed fourfold potency of amphotericin B in inhibiting the growth of A. clavatus (MIC 0.49 μg/mL) and C. albicans (MIC 0.12 μg/mL), respectively. The same compound showed twofold potency of gentamycin in inhibiting the growth of P. vulgaris (MIC 0.98 μg/mL), equipotent to the ampicillin and amphotericin B in inhibiting the growth of S. epidermidis (MIC 0.49 μg/mL), A. fumigatus (MIC 0.98 μg/mL), respectively. Thus, these studies suggest that quinoline derivatives bearing pyrazole moiety are interesting scaffolds for the development of novel antibacterial and antifungal agents.

Full text of DOI:10.1016/j.ejmech.2017.10.046

Accepted Manuscript
Quinoline derivatives bearing pyrazole moiety: Synthesis and biological evaluation as
possible antibacterial and antifungal agents
Mohamed F. El Shehry, Mostafa M. Ghorab, Samir Y. Abbas, Eman A. Fayed, Said
A. Shedid, Yousry A. Ammar
PII:
S0223-5234(17)30846-2
10.1016/j.ejmech.2017.10.046
EJMECH 9838
DOI:
Reference:
To appear in: European Journal of Medicinal Chemistry
Received Date: 5 June 2017
Revised Date: 13 October 2017
Accepted Date: 15 October 2017
Please cite this article as: M.F. El Shehry, M.M. Ghorab, S.Y. Abbas, E.A. Fayed, S.A. Shedid, Y.A.
Ammar, Quinoline derivatives bearing pyrazole moiety: Synthesis and biological evaluation as possible
antibacterial and antifungal agents, European Journal of Medicinal Chemistry (2017), doi: 10.1016/
j.ejmech.2017.10.046.
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ACCEPTED MANUSCRIPT
Quinoline derivatives bearing pyrazole moiety: Synthesis and biological evaluation as
possible antibacterial and antifungal agents
Graphical abstract:
R3
Cl
N
N
N
N
Cl
N
R
N
N
R2
N
H2N
X = CN, COOEt
R = CH3, SCH3, 3-Cl-C6H4
2,4-Cl2-C6H3
R1
H2N
MIC values (0.12 - 0.98 µg/mL)
X
CN
R1 = H, Ph,
R2, R3 = 2-phenoxyquinoline,
2-chlorophenyl, 4-methoxyphenyl
Antibacterial and antifungal activities
New three series of quinoline derivatives bearing a pyrazole moiety have been synthesized
and evaluated for antibacterial and antifungal activity.

ACCEPTED MANUSCRIPT
Quinoline derivatives bearing pyrazole moiety: Synthesis and biological evaluation as
possible antibacterial and antifungal agents
Mohamed F. El Shehry,a Mostafa M. Ghorab,b Samir Y. Abbas,c,* Eman A. Fayed,d
Said A. Shedide, Yousry A. Ammare,*
a Pesticide Chemistry Department, National Research Centre, Cairo 12622, Egypt.
b Pharmacognosy Department, Faculty of Pharmacy, King Saud University, Saudi Arabia.
c Organometallic and Organometalloid Chemistry Department, National Research Centre,
Cairo 12622, Egypt.
d
Pharmaceutical Organic Chemistry Department, Faculty of Pharmacy (Girls), Al-Azhar
University.
e Chemistry Department, Faculty of Science, Al-Azhar University, Cairo, Egypt.
*Corresponding authors: E-mail addresses: samiryoussef98@yahoo.com (S. Abbas);
yossry@yahoo.com (Y. Ammar).
Abstract: In an attempt for development of new antimicrobial agents, three series of
quinoline derivatives bearing pyrazole moiety have been synthesized. The first series was
synthesized through the synthesis of 4-(quinolin-2-yloxy)benzaldehyde and 4-(quinolin-2-
yloxy)acetophenone and then treatment with ketone or aldehyde derivatives to afford the
corresponding chalcones. Cyclization of the latter chalcones with hydrazine derivatives led to
the formation of new pyrazoline derivatives. The second series was synthesized via the
synthesis of 2-hydrazinylquinoline and then treatment with formylpyrazoles to afford the
corresponding hydrazonyl pyrazole derivatives. The third series was synthesized through the
treatment of 2-hydrazinylquinoline with ethoxyethylidene, dithioacetal and arylidene
derivatives to afford the corresponding pyrazole derivatives. The synthesized compounds
were evaluated for their expected antibacterial and antifungal activities; where, the majority
of these compounds showed potent antibacterial and antifungal activities against the tested
strains of bacteria and fungi. Pyrazole derivative 13b showed better results when compared
with the reference drugs as revealed from their MIC values (0.12 - 0.98 µg/mL). The pyrazole
derivative 13b showed fourfold potency of gentamycin in inhibiting the growth of S. flexneri
(MIC 0.12 µg/mL). Also, compound 13b showed fourfold potency of amphotericin B in
inhibiting the growth of A. clavatus (MIC 0.49 µg/mL) and C. albicans (MIC 0.12 µg/mL),
respectively. The same compound showed twofold potency of gentamycin in inhibiting the
growth of P. vulgaris (MIC 0.98 µg/mL), equipotent to the ampicillin and amphotericin B in
inhibiting the growth of S. epidermidis (MIC 0.49 µg/mL), A. fumigatus (MIC 0.98 µg/mL),
respectively. Thus, these studies suggest that quinoline derivatives bearing pyrazole moiety
are interesting scaffolds for the development of novel antibacterial and antifungal agents.
Keywords: Quinolines; Pyrazoles; Antibacterial and antifungal agents
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1. Introduction
Microbial infections are causing widespread and serious diseases. In order to prevent these
serious medical problems, the discovery of new types of antibacterial and antifungal agents is
a very important task. In recent years, the research has been focused on the development of
new antimicrobial agents, which may act through structure design and novel targets,
overcoming the problem of acquired resistance [1-4]. Quinoline derivatives possess very
good antibacterial as well as antitubercular activities [5-7] with a variety of other different
pharmacological activities such as anticancer [8], and antimalarial [9]. The prominent
antibacterials are fluoroquin- olones like Ciprofloxacin, Sparfoxacin, Gatifloxacin. The
antifungal-antiprozoal is Clioquinol, the antimalarials are Quinine, Quinidine, Chloroquine,
Mefloquine, Amodia- quinine, Primaquine. The antiviral is Saquinavir. Ciprofloxacin and
Moxifloxacin are showed significant antitubercular activity and are recommended by WHO
as second line anti-TB drugs [10]. Furthermore, quinoline moiety is found in a large variety
of naturally occurring compounds and also chemically useful synthons bearing diverse
bioactivities [11]. In this perspective, we have chosen the quinoline skeleton for the design of
new bioactive molecules. On the other hand, pyrazole derivatives possess a wide spectrum of
chemotherapeutic activities including antituberculosis, [12] antiviral [13] and anti-
inflammatory [14] activities. The majority of known quinoline drugs have a side chain on the
4- or 8-position of the quinoline building block. However, recently, it has been reported that
moving a functionalized side chain around the quinoline core to the other position can result
in retention of biological and providing new opportunities for the design of bioactive
compounds. These observations gave us an additional motivation to combination of the
quinoline scaffold with pyrazole derivatives at 2-position of the quinoline. Therefore, we
initiated a program to synergies the antimicrobial activity of quinoline and pyrazole in an
effort to discover potent antimicrobial agents.
2. Results and discussion
2.1. Chemistry
4-(Quinolin-2-yloxy)benzaldehyde 1 was obtained by the reaction of 2-choloroquinoline and
4-hydroxybenzaldehyde in DMF in the presence of anhydrous potassium carbonate (Scheme
1). Claisen-Schmidt condensation of 4-(quinolin-2-yloxy)benzaldehyde 1 with 4-
methoxyacetophenone in ethanolic sodium hydroxide furnished the chalcone derivative 2.
The structures of the latter products were derived from their spectroscopic as well as
elemental analyses. IR spectrum of compound 2 showed the characteristic bands for CH-
1
aliphatic, conjugated C=O and olefin C=C at 2927, 1658 and 1602 cm-1, respectively. Its H
NMR spectrum displayed a pair of a doublet signal at: δ = 7.78 ppm, with a coupling
constant indicating trans-olefinic protons. Cyclocondensation of chalcone 2 with hydrazine
hydrate in boiling ethanol furnished the respective pyrazoline 3. Also, cyclocondensation of
chalcone 2 with phenylhydrazine in boiling ethanol furnished the corresponding pyrazoline 4.
The structures of the pyrazolines 3 and 4 were derived from spectral data and elemental
analyses. IR spectra showed the disappearance of the C=O band of chalcones, and appearance
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of a strong band appeared at 1593-1599 cm-1 corresponding to C=N of the pyrazoline ring.
Pyrazoline 3 showed an additional sharp band at 3341 cm-1 due to their NH stretching
1
vibration. H NMR spectra of pyrazolines 3 and 4 displayed ABX spin system for protons
attached to the C-4 and C-5 carbon atoms of the pyrazoline ring. Chemical shifts and the
1
coupling constant values unequivocally prove the pyrazoline structures. H NMR spectra
revealed the signals of CH2 protons of the pyrazoline ring in the region 2.89-3.08 and 3.84-
3.87 ppm as a pair of doublets. The CH proton appeared as doublet of doublets at: δ = 4.87 &
5.32 ppm. Initially, the acetyl derivative 5 was obtained via coupling of 2-choloroquinoline
with 4-hydroxyacetophenone in DMF in the presence of anhydrous potassium carbonate
(Scheme 1). The presence of the acetyl group in compound 5 makes it a versatile precursor
for the synthesis of chalcones and pyrazoline derivatives. Thus, the Claisen-Schmidt
condensation of 5 with aldehyde derivatives (namely; 2-chlorobebalehyde and 4-
methoxybenzaldehyde) in ethanolic sodium hydroxide furnished the chalcone derivative
6a,b. Structure of the latter products was derived from their spectroscopic as well as
elemental analytical data. For example, IR spectrum of compound 6a showed the
1
characteristic band for conjugated C=O at 1657 cm-1 and its H NMR spectrum displayed a
pair of doublets at δ = 7.57 and 8.22 ppm, with a coupling constant indicating trans-olefinic
protons. Cyclocondensation of chalcones 6a,b with hydrazine hydrate in boiling ethanol
furnished the respective pyrazolines 7a,b. Similarly, cyclocondensation of chalcones 6a,b
with phenylhydrazine in boiling ethanol furnished the corresponding pyrazolines 8a,b. The
structures of the pyrazolines 7a,b and 8a,b were derived from spectral data and elemental
analyses. IR spectra showed the disappearance of the C=O band of chalcones. Pyrazolines
7a,b showed an additional sharp band in the region 3330-3317 cm-1 due to their NH
1
stretching vibration. H NMR spectra revealed the signals of CH2 protons of the pyrazoline
ring in the regions 2.89-2.92 and 3.80-3.82 ppm. CH proton appeared at: δ = 4.81-4.87 ppm.
Scheme 1:
2-Hydrazinylquinoline 9 [15] was prepared by the reaction of 2-choloroquinoline with
hydrazine hydrate in boiling ethanol (Scheme 2). Condensation of the 2-hydrazinylquinoline
9 with formylpyrazoles in ethanol under reflux afforded the respective hydrazone derivatives
10a-c. The structure of the hydrozonyl pyrazolines 10a-c was established on the basis of their
spectral data and elemental analyses. IR spectra showed bands in the region 3162 - 3183 cm-1
due to their NH stretching vibration. Beside the aromatic signals, singlet signal about 9.00
1
ppm are assigned for the azomethine proton. All H NMR spectra of pyrazolines 10a-c
exhibited broad exchangeable signal for the NH proton about 11.12, 11.17 ppm. Moreover,
13C NMR spectrum supported these assignments and added a strong evidence for these
interpretations.
Scheme 2:
2-Hydrazinylquinoline 9 is considered as starting material for the synthesis of many
substituted pyrazoline derivatives. Thus, treatment equimolar quantities of 2-
hydrazinylquinoline 9 and 2-(1-ethoxyethylidene)malononitrile in ethanol when heated under
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reflux gave a sole product, which was identified as 5-amino-4-cyano-3-methyl-pyrazole
derivative 11a as depicted in Scheme 3. By similar way, treatment equimolar quantities of 2-
hydrazinylquinoline 9 and ethyl 2-cyano-3-ethoxybut-2-enoate in ethanol under reflux gave
only a sole product, which was identified as 5-amino-4-ethylcarboxylate-3-methylpyrazole
derivative 11b. Interaction of 2-hydrazinylquinoline 9 with ketene dithioacetal derivative (2-
(bis(methylthio)methylene)malononitrile) in ethanol under reflux afforded 5-amino-4-cyano-
3-methylthio-pyrazole derivative 12a. 5-Amino-4-ethyl-carboxylate-3-methylthio-pyrazole
derivative 12b was prepared through the reaction of 2-hydrazinylquinoline with ketene
dithioacetal derivative [ethyl 2-cyano-3,3-bis(methylthio)acrylate] in ethanol under reflux.
Finally, 5-amino-4-cyano-3-aryl-pyrazole derivatives 13a,b were prepared through the
reaction of 2-hydrazinylquinoline with arylidene malononitrle derivatives in ethanol under
reflux. The structures of products were deduced from elemental analysis and spectroscopic
data.
Scheme 3:
2.2. Biological activates
2.2.1. Animal toxicity study
The acute toxicity is usually measured by LD50 (the median lethal dose) which is the dose
that kills 50% of the experimental animals under specified conditions. The LD50 will vary
according to many factors, e.g. animal strain, room temperature, route of administration,
season of the year, etc. Acute toxicity studies have to be carried out on several animal species
generally on mice and rats. The basic principle of the determination of the LD50 depends on
the determination of the highest dose that fails to kill any animal and this refers as the
threshold dose or the maximal tolerated dose and determination of the minimal dose that kills
all the animals, the former dose is referred to as LD0; while the latter dose is referred to as
LD100. In between these two doses, several doses are chosen which produce different
percentage of mortality. The methods of determination of the LD50 differ in the design of the
experiment and the method of calculation of LD50. The acute LD50 of the screened
compounds were determined by Spearmane Karber method [16]. All the newly synthesized
compounds were well tolerated up to the doses of 1200 mg/kg without any toxic
manifestations. The results suggest that the tested compounds have very low toxic effects
2.2.2. Antibacterial and antifungal activities
The synthesized compounds were tested in vitro for antibacterial and antifungal activities
against the following human pathogens strains: three Gram-positive bacteria, Staphylococcus
aureus (RCMB 010027), Staphylococcus epidermidis (RCMB 010024) and Bacillis subtilis
RCMB 010063; three Gram-negative bacteria, Proteous vulgaris (RCMB 010085), Klebsiella
pneumonia (RCMB 010093), and Shigella flexneri (RCMB 0100542), and three Fungi,
Aspergillus fumigatus (RCMB 02564), Aspergillus clavatus (RCMB 02593) and Candida
albicans (RCMB 05035). Agar-diffusion method [17] was used for the determination of the
preliminary screening of antibacterial and antifungal activities. The antifungal agents were
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evaluated against clinical isolates of standard strains of fungi by the broth dilution methods
according to NCCLs [18]. Antimicrobial tests were carried out using 100 µL of tested
compound solution prepared by dissolving 5 mg of the chemical compound in 1 mL of
dimethyl sulfoxide (DMSO). Ampicillin, Gentamycin and Amphotericin B (1 mg/mL) were
used as standard references for Gram-positive bacteria, Gram-negative bacteria and
antifungal activity, respectively. The results were recorded for each tested compound as the
average diameter of inhibition zones of bacterial or fungal growth around the discs in mm.
The inhibition zone diameters, attributed to the tested original concentration (5 mg/mL) as
a preliminary test, are shown in Table 1.
Table 1:
From the tabulated data, it was found that: the mean values of the inhibition zone diameter
obtained for these compounds suggest that all of the pyrazole derivatives possess significant
antimicrobial activity against most of the tested organisms used in these assays. The results of
antimicrobial screening revealed that most of the tested pyrazoles displayed variable
inhibitory effects on the growth of tested Gram-positive, Gram-negative bacterial and fungal
strains. In general, most of the studied compounds revealed better activity against the Gram-
positive rather than Gram-negative bacterial strains. It was also observed that transformation
of chalcone derivatives to the respective pyrazole derivatives increase the antibacterial
activity. As anticipated, a clear difference in antimicrobial activity is noted between
compounds within and between each series, pointing to the reinforcing and opposing effects
of substitution at pyrazole moiety. The results of the antimicrobial screening demonstrated
the following assumptions about the structural activity relationship (SAR). Inhibition of the
diameter zones values of antifungal activity showed similar trend as antibacterial activity.
Key precursor, chalcone 2 showed poor antimicrobial activity. For that reason, chalcone
derivatives 2 and 6a,b were chemically transformed to pyrazoline derivatives hoping to get
more potent antimicrobial agents. The cyclized target pyrazoline showed significant activity.
Regarding the effect of substitution at pyrazole moiety, it is evident that varying such a unit
may have a dramatic effect on antimicrobial activity, which may be augmented or reduced
depending on whether a matching or mismatching relationship exists with the substitution at
pyrazole moiety. The type of the substitutions on the pyrazoline ring is important. Using the
general structure provided in Fig. 1, certain aspects of the structure activity relationships for
these compounds can be more clearly highlighted.
Figure 1:
The results depicted in Table 1 and Fig. 2 revealed that the pyrazoline derivative 3 showed
moderate to good activity against the growth of the different tested organisms except K.
pneumonia, and its best result was observed against Gram-positive bacteria. Also, their
analogue, N-phenyl substituted pyrazoline derivative 4, showed moderate activity against all
the screened bacteria and fungi except B. subtilis and their potencies were weaker than their
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analogue, N-unsubstituted pyrazoline derivative 3. The moving a functionalized substitutions
around the pyrazole moiety to the other position resulted in retention of biological activity.
The moving functionalized substitutions in compound 4 around the pyrazole moiety to the
other position in case of compound 8b resulted in the highest antimicrobial activity among all
the compounds investigated in this study. Compound 8b exhibited the highest antibacterial
activity against most of the organisms, compound 8b exhibited activities near to the
references drugs (Ampicillin, Gentamycin and Amphotericin B). On the other hand, the
moving functionalized substitutions in compound 3 around the pyrazole moiety to the other
position in case of compound 7b did not improve the antimicrobial activity. The results
depicted in Fig. 2 revealed that the compound 7b showed moderate activity against the
growth of the different organisms. Further introduction of 2-chlorophenyl at position 5 of
pyrazoline, as in 7a, had a good effect on antibacterial activity, 7a showed strong activity
against the different organisms. Compound 7a showed better results when compared with
reference drug as revealed from their inhibition zone values. It showed near the reference
drug. Interestingly, unlike 7a, their analogue, N-phenyl substituted pyrazoline derivative 8a,
showed moderate activity against most of the screened bacteria and fungi. Compound 8a
resulted in the lowest antimicrobial activity among all the compounds investigated in this
series. Unfortunately, compound 8a was completely inactive against S. Epidermidis, S.
flexneri and A. clavatus. By investigating the biological activity of this series as antimicrobial
agents (Fig. 2), it was observed that compounds 7a and 8b were highly active with broad
spectrum activity against all the screened microbes.
Figure 2:
Concerning the antimicrobial activity of pyrazoline derivatives 10a-c, the results displayed
that pyrazoline derivatives 10a-c were highly active against all screened organisms. The
results depicted in Fig. 3 revealed that the antimicrobial activity of pyrazoline derivatives
10a-c was nearly equipotent to the reference drug against all screened organisms (Fig. 3).
Regarding the effect of changing the substituent on C-(3) of pyrazole from phenyl to
chlorophenyl to p-tolyl (10a → 10b → 10c); the presence of chlorophenyl moiety (10b)
resulted in the highest antibacterial activity. The presence of p-tolyl moiety resulted in the
lowest antibacterial activity. The presence of phenyl moiety resulted in the lowest antifungal
activity.
Figure 3:
Pyrazoline series 11a,b, 12a,b and 13a,b bearing quinolin-2-yl group at N-(1), amino group
at position 5 of pyrazole moiety, various substituent at position 3 and others at position 4 of
pyrazole moiety. The effects of each substituent at position 3 and those at position 4 on these
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activities was studied and make a comparative study between them to deduce a structure
activity relationship. Using the general structure provided in Fig. 3, certain aspects of the
structure activity relationships for these compounds can be more clearly highlighted.
Figure 4:
Introduction of methyl group at position 3 and carbonitrile at position 4 of pyrazoline, as in
11a, had a good effect on antibacterial activity, compound 11a showed good activities against
the different organisms. Changing the substituent at position 4 of pyrazoline from carbonitrile
to ethyl carboxylate and let the substituent position 3 not changed, as in 11b, had slight effect
on antibacterial activity. Introduction of methylthio group at position 3 and carbonitrile at
position 4 of pyrazoline, as in 12a, had a good effect on antibacterial activity, compound 12a
showed good activities against the different organisms. Changing the substituent at position 4
of pyrazoline from carbonitrile to ethyl carboxylate and let the substituent position 3 not
changed, as in 12b, had slight effect on antibacterial activity against gram positive Bactria.
On the other hand, this changing resulted bad effect on antibacterial activity against gram-
negative bacteria. Compound 12b showed no activities against gram-negative bacteria.
Alternative, 12b showed improve the antifungal activity. Changing the substituent at position
3 in 11a, from methyl to methylthio and let the substituent at position 4 (carbonitrile) of
pyrazoline not changed as in 12a, had slight effect on antibacterial activity. Compound 12a
was weaker than their analogue 11a. Changing the substituent at position 3 in 11b, from
methyl to methylthio and let the substituent at position 4 (ethyl carboxylate) of pyrazoline not
changed as in 12b, had slight effect against gram positive bactria and fungi and bad effect
against gram-negative bacteria. Compound 12b showed no activities against gram-negative
bacteria. Pyrazoline series 13a,b bear carbonitrile at position 4, and 3-chlorophenyl (or 2,4-
dichlorophenyl) substituent at position 3 of pyrazole moiety. The presence of 2,4-
dichlorophenyl (13b) resulted in the highest antimicrobial activity among all the compounds
investigated in this series. The presence of 2,4-dichlorophenyl moiety exhibited the highest
antibacterial activity against most of the organisms, 2,4-dichlorophenyl moiety exhibited
activities near to the references drug. Unlike 13b, their analogue, 3-chlorophenyl moiety 13a
showed moderate activity against most of the screened bacteria and fungi. Compound 13a
resulted in the lowest antimicrobial activity among all the compounds investigated in this
series. Among this series, compounds 13b showed good inhibitory activity against all the
screened Gram-positive bacteria (Fig. 5). Compounds 13b showed better results when
compared with ampicillin as revealed from their inhibition activities.
Figure 5:
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2.2.2. MIC of the most active compounds
The minimal inhibitory concentrations (MICs) for compounds that showed significant growth
inhibition zones were determined. The synthesized compounds 7a, 8b, 10a-c, 11a,b, 13b and
reference drugs was then evaluated in vitro using the twofold serial dilution technique [18].
The lowest concentration showing no growth was taken as the minimum inhibitory
concentration. The results of minimum inhibitory concentration were reported in Table 2.
Table 2:
Results revealed that majority of synthesized compounds showed varying degrees of
inhibition against the test panel of species. The obtained antimicrobial activity of tested
compounds could be correlated to structural variations and modifications. Pyrazole derivative
13b showed better results when compared with the reference drugs as revealed from their
MIC values (0.12-0.98 µg/mL). The pyrazole derivative 13b showed fourfold potency of
Gentamycin in inhibiting the growth of S. flexneri (MIC 0.12 µg/mL). Also, compound 13b
showed fourfold potency of Amphotericin B in inhibiting the growth of A. clavatus (MIC
0.49 µg/mL) and C. albicans (MIC 0.12 µg/mL), respectively. Compound 13b showed
twofold potency of Gentamycin in inhibiting the growth of P. vulgaris (MIC 0.98 µg/mL),
equipotent to the Ampicillin and Amphotericin B in inhibiting the growth of S. epidermidis
(MIC 0.49 µg/mL), A. fumigates (MIC 0.98 µg/mL), respectively. Pyrazole derivative 13b
displayed 50% less activity compared to Gentamycin against K. pneumonia (MIC 0.49
µg/mL). Moreover, Pyrazole derivative 13b showed narrow spectrum of activity of
Ampicillin toward S. aureus and B. subtilis on contrast to its activity toward the other
organisms. The comparison between the minimal inhibitory concentrations (MICs) of
compound 13b and standard drugs against the used Gram positive, Gram negative bacteria
and fungi was represented in Fig 6. Also, pyrazole derivative 8b showed better results when
compared with reference drugs as revealed from their MIC values (0.06-9.9 µg/mL). Pyrazole
derivative 8b showed twofold potency of Ampicillin in inhibiting the growth of S.
epidermidis (MIC 0.24 µg/mL); equipotent to the Gentamycin and Amphotericin B in
inhibiting the growth of S. flexneri (MIC 0.12 µg/mL) and C. albicans (MIC 0.48 µg/mL),
respectively. Pyrazole derivative 8b displayed 50% less activity compared to Amphotericin B
against A. fumigates (MIC 1.95 µg/mL), and 25% of the potency of Ampicillin against S.
aureus with MIC values (0.24 µg/mL). Pyrazole derivative 10c is equipotent to Amphotericin
B in inhibiting the growth of A. fumigatus and C. albicans (MIC 0.98 and 0.49 µg/mL,
respectively). Pyrazole derivative 10c displayed 50% less activity compared to Ampicillin
against S. epidermidis (MIC 0.98 µg/mL). Pyrazole derivative 7a showed twofold potency of
Gentamycin in inhibiting the growth of P. vulgaris (MIC 0.97 µg/mL). pyrazole derivative 9
displayed 50% less activity compared to ampicillin against S. epidermidis (MIC 0.97 µg/mL).
Figure 6:
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3. Conclusion
The aim of the present investigation is to synthesize different series of quinoline derivatives
which bearing a pyrazole moiety at position 2- to achieve the antimicrobial effect. The results
of this work clearly revealed that quinoline derivatives bearing a moiety pyrazole exhibited
good antimicrobial activity. Introduction α,β-unsaturated ketone at position 2 of quinoline
moiety decreased the antimicrobial activity. Transformation of α,β-unsaturated ketone group
into pyrazolines increases the antimicrobial activity. It is interesting to point out that
quinoline moiety incorporating substituted pyrazole moiety showed good antimicrobial
activity. The type of substituent on pyrazole moiety is important. The moving a
functionalized substitutions around the pyrazole moiety to the other position resulted in
retention of biological activity.
4. Experimental Section
All melting points are recorded on digital Gallen Kamp MFB-595 instrument and may be
uncorrected. The IR spectra (KBr) (cm-1) were measured on a JASCO spectrophotometer. 1H
NMR spectra were recorded on Bruker spectrometers (at 500 MHz) and are reported relative
13
to deuterated solvent signals in deuterated dimethylsulfoxide (DMSO-d6). C NMR spectra
were recorded on Bruker Spectrometers (at 125 MHz) in deuterated dimethylsulfoxide
(DMSO-d6). The antimicrobial screening and minimal inhibitory concentrations of the tested
compounds were carried out at the Regional Center for Mycology and Biotechnology, Al-
Azhar University, Cairo, Egypt.
4.1. Synthesis of 4-(quinolin-2-yloxy)benzaldehyde (1)
A mixture of 2-choloroquinoline (1.63 g, 0.01mol) and 4-hydroxybenzaldehyde (1.22 g,
0.01mol) were dissolved in DMF (50 mL) containing anhydrous potassium carbonate (2.0 g).
The mixture was heated in a water bath for 6 h. The mixture allowed to cool and poured into
crushed ice-cold water. The obtained product was collected by filtration and crystallized from
1
ethanol to give 1. Yield: 82%; m.p.: 106-108 °C; IR: ν/cm-1: 1695 (C=O); H NMR: 7.33 (d,
1H, J = 9.0 Hz, quinoline -H), 7.47 (d, 2H, J = 8.5 Hz, AB Ar-H), 7.50-7.57 (m, 1H,
quinoline-H), 7.66-7.68 (m, 2H, quinoline-H), 7.97 (d, 1H, J= 8.0 Hz, quinoline-H), 8.00 (d,
13
2H, J = 8.5 Hz, AB Ar-H), 8.45 (d, 1H, J= 9.0 Hz, quinoline-H), 10.02 (s, 1H, CHO); C
NMR: 113.6, 122.3 (2C), 125.8, 126.3, 127.6, 128.3, 130.7, 131.9, 133.3 (2C), 141.4, 146.0,
159.0, 161.0, 192.3 (CHO); Anal. Calcd for C16H11NO2 (249.26): C, 77.10; H, 4.45; N, 5.62;
Found: C, 77.32; H, 4.35; N, 5.43 %.
4.2. Synthesis of 1-(4-methoxyphenyl)-3-(4-(quinolin-2-yloxy)phenyl)prop-2-en-1-one (2)
The aldehyde 1 (2.49 g, 0.01mol) and 4-methoxyacetophenone (1.50 g, 0.01mol) were taken
in ethanol (25 mL), cooled 10 % aqueous NaOH solution (2.5 mL) was added to the above
- 9 -

ACCEPTED MANUSCRIPT
solution with constant stirring, until the turbidity appears. The reaction mixture was further
stirred for 2 h and left overnight. The mixture was carefully acidified using dilute
hydrochloric acid to obtain solid precipitate. The obtained product was filtered, washed with
water and crystallized from ethanol to give chalcone 2. Yield: 78 %; m.p.: 154-156 °C; IR:
1
ν/cm-1: 2927 (CH-aliph.), 1658 (C=O), 1602 (olefin C=C); H NMR: 3.88 (s, 3H, OCH3),
7.09 (d, 2H, J = 8.5 Hz, AB Ar-H), 7.30 (d, 1H, J = 9.0 Hz, quinoline-H), 7.35 (d, 2H, J = 8.0
Hz, AB Ar-H), 7.49 (s, 1H, quinoline-H), 7.66-7.68 (m, 2H, quinoline-H), 7.78 (d, 1H, J =
15.5 Hz, olefinic CH), 7.98-8.00 (m, 4H, Ar-H + olefinic CH), 8.20 (d, 2H, J = 8.5 Hz, AB
Ar-H), 8.45 (d, 1H, J = 8.5 Hz, quinoline-H); 13C NMR: 56.1 (OCH3), 113.5, 114.5 (2C),
122.1, 122.4 (2C), 125.6, 126.1, 127.5, 128.3, 130.6, 130.8 (2C), 131.0, 131.4 (2C), 132.0,
141.2, 142.9, 146.0, 155.6, 161.5, 163.7, 187.8 (C=O); Anal. Calcd for C25H19NO3 (381.42):
C, 78.72; H, 5.02; N, 3.67; Found: C, 78.54; H, 4.92; N, 3.47 %.
4.3. Synthesis of 2-(4-(3-(4-methoxyphenyl)-4,5-dihydro-1H-pyrazol-5-yl)phenoxy)quin-
oline (3)
To a solution of the chalcone 2 (3.81 g, 0.01mol) in ethanol (60 mL), hydrazine hydrate (0.6
mL, 0.012mol) was added. The reaction mixture was heated under reflux for 4 h. After
cooling the separated solid was filtered and crystallized from ethanol to give the pyrazoline 3.
1
Yield: 80 %; m.p.: 112-114 °C; IR: ν/cm-1: 3341 (NH), 2836 (CH-aliph.), 1599 (C=N); H
NMR: 2.89 (dd, 1H, JAX = 9.76 Hz, JAB= 16.43 Hz, pyrazoline C4-HA), 3.84 (dd, 1H, JBX
=
7.11 Hz, JBA = 16.31 Hz, pyrazoline C4-HB), 3.88 (s, 3H, OCH3), 4.87 (dd, 1H, JAX = 7.22
Hz, JBX = 9.71 Hz, pyrazoline C5-HX), 6.95 (d, 2H, J = 9.0 Hz, AB Ar-H), 7.22-7.26 (m, 3H,
Ar-H), 7.44-7.51 (m, 4H, Ar-H), 7.60 (d, 2H, J = 9.0 Hz, AB Ar-H), 7.64-7.68 (m, 2H,
quinoline-H), 7.95 (d, 1H, J= 10.0 Hz, NH exchangeable by D2O), 8.41 (d, 1H, J= 9.0 Hz,
13
quinoline-H); C NMR: 41.2 (CH2), 55.6 (OCH3), 63.6, 113.4, 114.5, 121.9, 125.4, 126.0,
127.0, 127.4, 127.5, 127.6, 128.3, 128.4, 130.5, 139.9, 140.9, 146.1, 149.4, 159.9, 161.8
(C=N); Anal. Calcd for C25H21N3O2 (395.45): C, 75.93; H, 5.35; N, 10.63; Found: C, 75.87;
H, 5.26; N, 10.78 %.
4.4. Synthesis of 2-(4-(3-(4-methoxyphenyl)-1-phenyl-4,5-dihydro-1H-pyrazol-5-yl)phen-
oxy)quinoline (4)
A mixture of chalcone 2 (3.81 g, 0.01mol) and phenylhydrazine (1.08 g, 0.01mol) in ethanol
(60 mL) was heated under reflux for 6 h. After cooling the separated solid was filtered and
crystallized from ethanol to give the pyrazolinone 4. Yield 75 %; mp 139-141 °C; IR: ν/cm-1:
2913 (CH-aliph.), 1593 (C=N); 1H NMR: 3.08 (m, 1H, pyrazoline C4-H), 3.87 (s, 3H, OCH3),
3.94 (m, 1H, pyrazoline C4-H), 5.32 (m, 1H, pyrazoline C5-H), 6.70 - 6.90 (m, 3H, Ar-H),
7.00 - 7.15 (m, 4H, Ar-H), 7.24 (d, 2H, J = 7.0 Hz, Ar-H), 7.30-7.35 (m, 3H, Ar-H), 7.52 (m,
1H, Ar-H), 7.64 (m, 2H, Ar-H), 7.84 (d, 2H, J = 7.0 Hz, Ar-H), 8.01 (d, 1H, J = 7.0 Hz, Ar-
13
H), 8.54 (d, 1H, J = 8.0 Hz, Ar-H); C NMR: 43.5, 55.5 (OCH3), 63.2, 113.4, 113.4 (2C),
114.8 (2C), 118.9, 122.3 (2C), 125.5, 126.0, 127.5 (3C), 127.5 (2C), 128.2, 129.3 (2C),
129.5, 130.5, 134.9, 141.0, 144.8, 146.0, 147.2, 154.2, 158.9 (C=N), 161.6 (C=N); Anal.
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ACCEPTED MANUSCRIPT
Calcd for C31H25N3O2 (471.55): C, 78.96; H, 5.34; N, 8.91; Found: C, 78.78; H, 5.21; N, 8.72
%.
4.5. Synthesis of 1-(4-(quinolin-2-yloxy)phenyl)ethanone (5)
A mixture of 2-choloroquinoline (1.63 g, 0.01mol) and 4-hydroxyacetophenone (1.36 g,
0.01mol) were dissolved in DMF (50 mL) containing anhydrous potassium carbonate (2 g).
The mixture was heated under reflux for 12 h., then allowed to cool and poured into crushed
ice-cold water. The obtained product was collected by filtration and crystallized from ethanol
1
to give 5. Yield: 85 %; m.p.: 117-119 °C; IR: ν/cm-1: 2957 (CH-alph.), 1671 (C=O); H
NMR: 2.30 (s, 3H, CH3), 7.31 (d, 1H, J = 9.0 Hz, quinoline-H), 7.38 (d, 2H, J = 8.5 Hz, AB
Ar-H), 7.49 (s, 1H, quinoline-H), 7.66-7.68 (m, 2H, quinoline-H), 7.96 (d, 1H, J= 8.0 Hz,
13
quinoline-H), 8.05 (d, 2H, J= 8.5 Hz, AB Ar-H), 8.45 (d, 1H, J = 9.0 Hz, quinoline-H); C
NMR: 27.1 (CH3), 113.5, 121.8, 125.7, 126.2, 127.6, 128.3, 130.6, 130.7, 133.9, 141.3,
146.0, 161.2, 162.8, 197.2 (C=O); Anal. Calcd for C17H13NO2 (263.29): C, 77.55; H, 4.98; N,
5.32; Found: C, 77.71; H, 4.82; N, 5.46 %.
4.6. General method for the preparation of chalcone derivatives 6a,b
The acetophenone derivative 5 (2.63, 0.01mol) and the selected aldehydes (namely, 2-
chlorobenzaldehyde and 4-methoxybenzaldehyde) (0.01 mol) were dissolved in ethanol (25
mL) and cooled. 10 % Aqueous NaOH solution (2.5 mL) was added to the above solution
with constant stirring, until the turbidity appears. The reaction mixture was further stirred for
2 h and left overnight. The mixture was carefully acidified using dilute hydrochloric acid to
obtain solid precipitate. The obtained product was filtered, washed with water and
crystallized from ethanol to give the chalcone derivatives 6a,b
4.6.1. 3-(2-Chlorophenyl)-1-(4-(quinolin-2-yloxy)phenyl)prop-2-en-1-one (6a): Yield:
77%; m.p.: 125-127 °C; IR: ν/cm-1: 1657 (C=O), 1602 (olefin C=C); 1H NMR: 7.30 (d, 1H, J
= 9.5 Hz, quinoline-H), 7.43-7.54 (m, 5H, Ar-H), 7.57 (d, 1H, J = 7.0 Hz, olefinic CH), 7.66-
7.68 (m, 2H, quinoline-H), 7.96 (d, 1H, J = 8.0 Hz, quinoline-H), 8.04-8.15 (m, 2H, Ar-H),
8.22 (d, 1H, J = 9.0, olefinic CH ), 8.30 (d, 2H, J = 8.0 Hz, AB Ar-H), 8.46 (d, 1H, J = 8.5
13
Hz, quinoline-H); C NMR: 113.6, 121.9, 125.2, 125.8, 126.3, 127.6, 128.1, 128.3, 129.1,
130.5, 130.7, 131.2, 132.4, 132.8, 134.2, 134.9, 138.9, 141.3, 146.0, 158.2, 161.1, 188.2
(C=O); Anal. Calcd for C24H16ClNO2 (385.84): C, 74.71; H, 4.18, N, 3.63; Found: C, 74.58;
H, 4.23, N, 3.47 %.
4.6.2. 3-(4-Methoxyphenyl)-1-(4-(quinolin-2-yloxy)phenyl)prop-2-en-1-one (6b): Yield:
1
67 %; m.p.: 128-130 °C; IR: ν/cm-1: 2923 (CH-aliph.), 1652 (C=O), 1593 (olefin C=C); H
NMR: 3.83 (s, 3H, OCH3), 7.02 (d, 2H, J = 8.5 Hz, AB Ar-H), 7.32 (d, 1H, J = 9.0 Hz,
quinoline-H), 7.43 (d, 2H, J = 8.0 Hz, AB Ar-H), 7.49-7.51 (m, 1H, quinoline-H), 7.66-7.68
(m, 2H, quinoline-H), 7.77 (d, 1H, J = 14.3 Hz, olefinic CH), 7.85-7.92 (m, 3H, Ar-H +
olefinic CH), 8.05 (d, 1H, J = 8.5 Hz, quinoline- H), 8.20 (d, 2H, J = 8.0 Hz, AB Ar-H), 8.48
13
(d, 1H, J= 8.5 Hz, quinoline-H); C NMR: 55.9 (OCH3), 113.6, 114.9, 119.9, 121.9, 125.8,
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ACCEPTED MANUSCRIPT
126.2, 127.6, 127.8, 128.3, 130.7, 130.9, 131.3, 134.8, 141.3, 144.4, 146.0, 157.8, 161.2,
161.9, 188.3 (C=O); Anal. Calcd for C25H19NO3 (381.42): C, 78.72; H, 5.02; N, 3.67; Found:
C, 78.64; H, 4.98; N, 3.73 %.
4.7. General method for the preparation of 4,5-dihydropyrazole derivatives 7a,b
To a solution of the chalcone derivatives 6a or 6b (0.01mol) in ethanol (60 mL), hydrazine
hydrate (0.6 g, 0.012mol) was added. The reaction mixture was heated under reflux for 4 h.
After cooling the separated solid was filtered and crystallized from ethanol.
4.7.1. 2-(4-(5-(2-Chlorophenyl)-4,5-dihydro-1H-pyrazol-3-yl)phenoxy)quinoline (7a):
1
Yield: 80 %; m.p.: 102-104 °C; IR: ν/cm-1: 3317 (NH), 1594 (C=N); H NMR: 2.89 (s, 1H,
pyrazoline C4-HA), 3.80 (s, 1H, pyrazoline C4-HB), 4.87 (s, 1H, pyrazoline C5-HX), 7.00-7.51
(m, 9H, Ar-H), 7.60-7.68 (m, 4H, Ar-H), 7.87 (d, 1H, J = 10.0 Hz, NH exchangeable by
D2O), 8.45 (d, 1H, J = 9.0 Hz, quinoline-H); 13C NMR: 41.1 (CH2), 63.5, 113.7, 114.2,
121.5, 125.3, 126.1, 127.0, 127.3, 127.8, 127.6, 128.3, 128.9, 130.5, 139.9, 141.1, 146.1,
149.5, 160.2, 161.7; Anal. Calcd for C24H18ClN3O (399.87): C, 72.09; H, 4.54; N, 10.51;
Found: C, 72.23; H, 4.42; N, 10.72 %.
4.7.2. 2-(4-(5-(4-Methoxyphenyl)-4,5-dihydro-1H-pyrazol-3-yl)phenoxy)quinoline (7b):
1
Yield: 82%; m.p.: 129-131 °C; IR: ν/cm-1: 3330 (NH), 1558 (C=N); H NMR: 2.92 (s, 1H,
pyrazoline C4-HA), 3.82 (s, 1H, pyrazoline C4-HB), 3.88 (s, 3H, OCH3), 4.81 (s, 1H,
pyrazoline C5-HX), 7.00-7.26 (m, 5H, Ar-H), 7.40-7.50 (m, 4H, Ar-H), 7.62 (d, 2H, J = 9.0
Hz, AB Ar-H), 7.60-7.70 (m, 2H, quinoline-H), 7.93 (d, 1H, J = 10.0 Hz, NH), 8.44 (d, 1H, J
13
= 9.0 Hz, quinoline-H); C NMR: 41.3, 55.5 (OCH3), 63.4, 113.1, 114.4 (2C), 121.8 (2C),
125.2, 125.7, 126.8 (2C), 127.3, 127.6, 127.5, 128.2, 128.3 (2C), 130.6, 139.8, 140.8, 146.0,
149.3, 159.8 (C=N), 161.8 (C=N); Anal. Calcd for C25H21N3O2 (395.45): C, 75.93; H, 5.35;
N, 10.63; Found: C, 76.08; H, 5.21; N, 10.74 %.
4.8. General method for the preparation of 4,5-dihydropyrazole derivatives 8a,b
To a solution of the chalcone derivatives 6a or 6b (0.01mol) in ethanol (60 mL),
phenylhydrazine (1.08mol) was added. The reaction mixture was heated under reflux for 8 h.
After cooling the separated solid was filtered and recrystallized from ethanol to give 4,5
dihydropyrazole derivatives 8a,b
4.8.1. 2-(4-(5-(2-Chlorophenyl)-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl)phenoxy)quinol-
1
ine (8a): Yield: 75 %; m.p.: 175-177 °C; IR: ν/cm-1: 1591 (C=N); H NMR: 3.13 (dd, 1H,
JAX = 9.76 Hz, JAB = 16.43 Hz, pyrazoline C4-HA), 4.07 (dd, 1H, JBX = 7.11 Hz, JBA = 16.31
Hz, pyrazoline C4-HB), 5.78 (dd, 1H, JAX = 7.22 Hz, JBX = 9.71 Hz, pyrazoline C5-HX), 6.75
(t, 1H, J = 8.5 Hz, Ar-H), 6.95 (d, 2H, J = 9.0 Hz, Ar-H),7.15-7.36 (m, 8H, Ar-H), 7.51 (t,
1H, J = 8.5 Hz, Ar-H), 7.56 (d, 1H, Ar-H), 7.64-7.68 (m, 2H, Ar-H), 7.84 (d, 2H, J = 9.0 Hz,
Ar-H), 7.95 (d, 1H, J = 10.0 Hz, Ar-H), 8.42 (d, 1H, J = 9.0 Hz, Ar-H); 13C NMR: 19.0, 56.5,
113.1, 113.4, 122.3, 125.5, 127.5, 127.7, 128.3, 128.4, 129.6, 129.8, 130.6, 141.1, 144.8,
- 12 -

ACCEPTED MANUSCRIPT
146.1, 147.2, 154.2, 159.0, 161.7 (C=N); Anal. Calcd for C30H22ClN3O (475.97): C, 75.70;
H, 4.66; N, 8.83; Found: C, 75.62; H, 4.61; N, 8.93 %.
4.8.2. 2-(4-(5-(4-Methoxyphenyl)-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl)phenoxy)quino-
1
line (8b): Yield: 77 %; m.p.: 145-147 °C; IR: ν/cm-1: 2835 (CH-aliph.), 1597 (C=N); H
NMR: 3.10 (dd, 1H, JAX = 9.76 Hz, JAB =16.43 Hz, pyrazoline C4-HA), 3.87 (s, 3H, OCH3),
3.90 (dd, 1H, JBX = 7.11 Hz, JBA= 16.31 Hz, pyrazoline C4-HB), 5.44 (dd, 1H, JAX = 7.22 Hz,
JBX = 9.71 Hz, pyrazoline C5-HX), 6.72 (s, 1H, Ar-H), 6.90 (d, 2H, J = 8.0 Hz, Ar-H), 7.03 (d,
2H, J= 7.0 Hz, Ar-H), 7.16-7-20 (m, 2H, Ar-H), 7.23 (d, 2H, J = 7.0 Hz, Ar-H), 7.29-7.32
(m, 3H, Ar-H), 7.50 (s, 1H, Ar-H), 7.66-7.69 (m, 2H, Ar-H), 7.82 (d, 2H, J = 7.0 Hz, Ar-H),
7.95 (d, 1H, J =7.0 Hz, Ar-H), 8.42 (d, 1H, J = 8.0 Hz, Ar-H); 13C NMR: 55.5 (OCH3), 63.3,
113.4, 113.5, 114.8, 119.0, 122.3, 125.5, 126.1, 127.5, 127.6, 128.3, 129.3, 129.6, 130.6,
134.9, 141.1, 144.8, 146.1, 147.2, 154.2, 159.0, 161.7 (C=N); Anal. Calcd for C31H25N3O2
(471.55): C, 78.96; H, 5.34; N, 8.91; Found: C, 79.12; H, 5.41; N, 8.87 %.
4.9. General procedure for the condensation of the 2-hydrazinylquinoline 9 with
formylpyrazoles to afford 10a-c
To a solution of the 2-hydrazinylquinoline 9 [15] (1.45g, 0.01mol) in ethanol (30 mL),
formylpyrazoles (0.01 mol) were added and the reaction mixture was heated under reflux for
3 h. The solid obtained upon cooling was collected by filtration, dried and crystallized from
dioxane.
4.9.1. 2-(2-((1,3-Diphenyl-1H-pyrazol-4-yl)methylene)hydrazinyl)quinoline (10a): Yield:
1
87 %; m.p.: 130-132 °C; IR: ν/cm-1: 3162 (NH), 1608 (C=N); H NMR: 7.28 (t, 1H, J = 7.5
Hz, Ar-H), 7.37 (t, 1H, J = 7.5 Hz, Ar-H), 7.48 (t, 1H, J = 7.5 Hz, Ar-H), 7.53-7.63 (m, 7H,
Ar-H), 7.76-7.80 (m, 3H, Ar-H), 8.01 (d, 2H, J = 8.0 Hz, Ar-H), 8.14 (d, 1H, J = 9.0 Hz, Ar-
13
H), 8.28 (s, 1H, Ar-H), 9.01 (s, 1H, CH=N), 11.12 (br, 1H, NH exchangeable by D2O); C
NMR: 110.1, 118.5, 119.0, 122.8, 124.6, 126.2, 127.2, 127.3, 128.3, 128.9, 129.0, 130.0,
130.1, 133.1, 133.1, 138.2, 139.7, 147.7, 151.2, 156.3 (C=N); Anal. Calcd for C25H19N5
(389.45): C, 77.10; H, 4.92; N, 17.98; Found: C, 77.23; H, 4.82; N, 17.91 %.
4.9.2. 2-(2-((3-(4-Chlorophenyl)-1-phenyl-1H-pyrazol-4-yl)methylene)hydrazinyl)quino-
1
line (10b): Yield: 88 %; m.p.: 295-297 °C; IR: ν/cm-1: 3174 (NH), 1671 (C=N); H NMR:
7.20-7.50 (m, 3H, Ar-H), 7.50-7.60 (m, 7H, Ar-H), 7.76-7.80 (m, 3H, Ar-H), 8.03-8.15 (m,
2H, Ar-H), 8.31 (s, 1H, Ar-H), 9.04 (s, 1H, CH=N), 11.17 (br, 1H, NH exchangeable by
13
D2O); C NMR: 110.0, 118.4, 119.2 (2C), 122.6, 124.4, 126.0, 127.1, 127.3, 128.4, 128.8
(2C), 129.2 (2C), 130.0 (2C), 130.5, 132.0, 133.1, 133.7, 138.2, 139.7, 147.7, 151.2 (C=N),
156.3 (C=N); Anal. Calcd for C25H18ClN5 (423.90): C, 70.84; H, 4.28; N, 16.52; Found: C,
70.76; H, 4.24; N, 16.45 %.
4.9.3. 2-(2-((1-Phenyl-3-p-tolyl-1H-pyrazol-4-yl)methylene)hydrazinyl)quinoline (10c):
1
Yield: 80 %; m.p.: 151-153 °C; IR: ν/cm-1: 3183 (NH), 1603 (C=N); H NMR: 2.01 (s, 3H,
CH3), 7.30-7.37 (m, 2H, Ar-H), 7.43-7.63 (m, 8H, Ar-H), 7.73-7.82 (m, 3H, Ar-H), 8.03-8.17
- 13 -

ACCEPTED MANUSCRIPT
(m, 2H, Ar-H), 8.28 (s, 1H, Ar-H), 9.05 (s, 1H, CH=N), 11.17 (br, 1H, NH exchangeable by
D2O); 13C NMR: 21.2, 110.1, 118.5, 119.3 (2C), 122.7, 124.2, 126.1, 127.4, 127.2, 128.1,
128.9 (2C), 129.2 (2C), 130.1 (2C), 130.8, 132.1, 133.5, 133.2, 138.4, 139.6, 147.4, 151.0
(C=N), 156.7 (C=N); Anal. Calcd for C26H21N5 (403.48): C, 77.40; H, 5.25; N, 17.36;
Found: C, 77.54; H, 5.31; N, 17.46 %.
4.10. General procedure of synthesis of ethyl 5-amino-3-(methylthio)-1H-pyrazole
derivatives 11a,b
To a solution of 2-hydrazinylquinoline 9 (1.45g, 0.01mol) in ethanol (50 mL), 2-(1-
ethoxyethylidene)malononitrile or 2-(1-ethoxyethylidene)ethyl cyanoacetate (0.01mol) were
added and the reaction mixture was heated under reflux for 4 h. The solid obtained upon
cooling was collected by filtration, dried and crystallized from butanol.
4.10.1. 5-Amino-3-methyl-1-(quinolin-2-yl)-1H-pyrazole-4-carbonitrile (11a): Yield: 78
1
%; m.p.: 246-248 °C; IR: ν/cm-1: 3368, 3272 (NH2), 2918 (CH-aliph.), 2218 (C≡N); H
NMR: 2.24 (s, 3H, CH3), 7.59 (s, 1H, quinoline-H), 7.79 (s, 1H, quinoline-H), 8.00-8.11 (m,
13
3H, quinoline-H), 8.40-8.50 (m, 3H, quinoline-H + NH2 exchangeable by D2O); C NMR:
13.2, 74.3, 113.2 (2C), 126.0, 126.7, 128.1, 128.4, 131.2 (2C), 140.3, 145.4, 151.7, 154.2;
MS (m/z: %): 249 (M+, 100), 250 (M+1, 20.7), 242 (M-NH2, 41.9), 184 (24.7), 143 (26.8),
129 (59.1) 102 (36.8), 77 (34.58); Anal. Calcd for C14H11N5 (249.27): C, 67.46; H, 4.45; N,
28.10; Found: C, 67.57; H, 4.38; N, 28.27 %.
4.10.2. Ethyl 5-amino-3-methyl-1-(quinolin-2-yl)-1H-pyrazole-4-carboxylate (11b):
Yield: 74 %; m.p.: 154-156 °C; IR: ν/cm-1: 3429, 3301 (NH2), 2967, 2922 ( CH-aliph.), 1668
(C=O); 1H NMR: 1.23 (t, 3H, J = 6.9 Hz, CH3-ester), 2.34 (s, 3H, CH3), 4.23 (q, 2H, J = 7.0
Hz, CH2-ester), 7.59 (s, 1H, quinoline-H), 7.81 (s, 1H, quinoline-H), 8.00-8.11 (m, 4H,
quinoline-H), 8.52 (br, 2H, NH2 exchangeable by D2O); 13C NMR: 14.9 (CH3), 15.1 (CH3
ester), 59.5 (CH2), 93.4, 113.2, 126.0, 126.5, 127.9, 128.4, 131.2, 140.2, 145.4, 151.0, 153.2
(C=O); MS (m/z: %): 296 (M+, 86), 250 (M-COOC2H5, 20.7), Anal. Calcd for C16H16N4O2
(296.32): C, 64.85; H, 5.44; N, 18.91; Found: C, 64.74; H, 5.42; N, 18.78 %.
4.11. General procedure of synthesis of ethyl 5-amino-3-(methylthio)-1H-pyrazole
derivatives 12a,b
To a solution of 2-hydrazinylquinoline 9 (1.45g, 0.01mol) in ethanol (50 mL), substituted
ketene dithioacetals (0.01 mol) were added and the reaction mixture was heated under reflux
for 4 h. The solid obtained upon cooling was collected by filtration, dried and crystallized
from butanol.
4.11.1.
5-Amino-3-(methylthio)-1-(quinolin-2-yl)-1H-pyrazole-4-carbonitrile
(12a):
Yield: 80 %; m.p.: 233-235 °C; IR: ν/cm-1: 3367, 3270 (NH2), 2915 (CH-aliph.), 2217
(C≡N); 1H NMR: 2.61 (s, 3H, SCH3), 7.58 (t, 1H, J = 7.5 Hz, quinoline-H), 7.78 (t, 1H, J =
7.5 Hz, quinoline-H), 7.97 (d, 1H, J = 8.0 Hz, quinoline-H), 8.01 (d, 1H, J= 8.5 Hz,
- 14 -

ACCEPTED MANUSCRIPT
13
quinoline-H), 8.47-8.52 (m, 4H, quinoline-H + NH2 exchangeable by D2O); C NMR: 13.4
(CH3), 73.5 (C=C-pyrazole), 113.1, 114.1, 126.0, 126.7, 128.1, 128.4, 131.2, 140.4, 145.2,
151.3, 152.5, 154.8; MS (m/z: %): 281 (M+, 79.4), 250 (M+1, 14.7), 234 (20.4), 144 (29.7),
143 (26.8), 128 (100) 109 (62.8), 77 (36.8); Anal. Calcd for C14H11N5S (281.34): C, 59.77; H,
3.94; N, 24.89; Found: C, 59.62; H, 3.89; N, 25.01 %.
4.11.2.
Ethyl
5-amino-3-(methylthio)-1-(quinolin-2-yl)-1H-pyrazole-4-carbo-xylate
(12b): Yield: 82 %; m.p.: 124-126 °C; IR: ν/cm-1: 3439, 3311 (NH2), 2977 (CH-aliph.), 1691
1
(C=O); H NMR: 1.31 (t, 3H, J = 6.5 Hz, CH3-ester), 2.54 (s, 3H, SCH3), 4.24 (q, 2H, J =
6.5 Hz, CH2-ester), 7.57 (t, 1H, J = 8.0 Hz, quinoline-H), 7.79 (t, 1H, J= 7.5 Hz, quinoline-
H), 7.97 (d, 1H, J = 8.0 Hz, quinoline-H), 8.05 (d, 1H, J= 8.5 Hz, quinoline-H), 8.03-8.07
(m, 3H, quinoline-H + NH2 exchangeable by D2O), 8.52 (d, 1H, J = 9.0 Hz, quinoline-H); 13C
NMR: 12.8 (CH3), 14.9 (CH3), 59.7 (CH2), 92.8 (C=C-pyrazole), 113.1, 126.0, 126.5, 127.9,
128.4, 131.2, 140.2, 145.3, 151.2, 152.8, 153.5 (C=N), 163.4 (C=O); Anal. Calcd for
C16H16N4O2S (328.39): C, 58.52; H, 4.91; N, 17.06; Found: C, 58.63; H, 4.93; N, 17.12 %.
4.12. General procedure of synthesis of ethyl 5-amino-3-(methylthio)-1H-pyrazole
derivatives 13a,b
To a solution of 2-hydrazinylquinoline 9 (1.45g, 0.01mol) in ethanol (50 mL), aryledine
derivatives (0.01mol) were added and the reaction mixture was heated under reflux for 4 h.
The solid obtained upon cooling was collected by filtration, dried and recrystallized from
butanol.
4.12.1. 5-Amino-3-(3-chlorophenyl)-1-(quinolin-2-yl)-1H-pyrazole-4-carbonitrile (13a):
1
Yield: 75 %; m.p.: 211-213 °C; IR: ν/cm-1: 3378, 3282 (NH2), 2213 (C≡N); H NMR: 7.56-
7.60 (m, 3H, Ar-H), 7.80 (t, 1H, J = 8.0 Hz, Ar-H), 7.92 (d, 1H, J = 8.0 Hz, Ar-H), 7.97 (s,
1H, Ar-H), 8.00 (d, 1H, J= 8.0 Hz, Ar-H), 8.14 (d, 1H, J = 8.5 Hz, Ar-H), 8.18 (d, 1H, J =
13
9.0 Hz, Ar-H), 8.51-8.59 (m, 3H, Ar-H + NH2); C NMR: 71.8, 113.4, 115.4, 125.3, 126.3,
127.0, 128.2, 128.4, 130.0, 131.3, 131.3, 133.1, 134.1, 140.5, 145.2, 149.6, 152.7, 155.5
(2C=N); MS (m/z: %): 345 (M+, 76): Anal. Calcd for C19H12ClN5 (345.79): C, 66.00; H,
3.50; N, 20.25; Found: C, 66.12; H, 3.43; N, 20.37 %
.
4.12.2.5-
Amino-3-(2,4-dichlorophenyl)-1-(quinolin-2-yl)-1H-pyrazole-4-carbonitrile
(13b): Yield: 77 %; m.p.: 116-118 °C; IR: ν/cm-1: 3359, 3230 (NH2), 2200 (C≡N); 1H NMR:
7.50-7.90 (m, 5H, Ar-H), 8.00-8.20 (m, 3H, Ar-H), 8.50-8.60 (m, 3H, Ar-H + NH2
exchangeable by D2O); 13C NMR: 12.8 (CH3), 14.9 (CH3), 59.7 (CH2), 92.8 (C=C-pyrazole),
113.1, 126.0, 126.5, 127.9, 128.4, 131.2, 140.2, 145.3, 151.2, 152.8 (C=N), 153.5 (C=N),
163.4 (C=O); Anal. Calcd for C19H11Cl2N5 (380.23): C, 60.02; H, 2.92; N, 18.42; Found: C,
60.14; H, 2.87; N, 18.54 %.
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ACCEPTED MANUSCRIPT
4.13. Antimicrobial activity
Chemical compounds were individually tested against a panel of gram positive, gram
negative bacterial pathogens and fungi. Antimicrobial tests were carried out by the agar well
diffusion method using 100 µL of suspension containing 1 x108 CFU/mL of pathological
tested bacteria and 1 x106 CFU/mL of fungi spread on nutrient agar and Sabouraud dextrose
agar media, respectively. After the media had cooled and solidified, wells (10 mm in
diameter) were made and loaded with 100 µL of tested compound solution prepared by
dissolving 5 mg of the chemical compound in one mL of dimethyl sulfoxide (DMSO). The
inoculated plates were then incubated for 24 h at 37 °C for bacteria, and 72 h at 28 °C for
fungi. Negative controls were prepared using DMSO employed for dissolving the tested
compound. Ampicillin, Gentamycin and Amphotericin B (1 mg/mL) were used as standard
for antibacterial and antifungal activity, respectively. After incubation time, antimicrobial
activity was evaluated by measuring the zone of inhibition against the test organisms and
compared with that of the standard. The observed zone of inhibition is presented in Table 1.
Antimicrobial activities were expressed as inhibition diameter zones in millimeters (mm).
The experiment was carried out in triplicate and the average zone of inhibition was
calculated.
4.14. Minimal inhibitory concentration (MIC) measurement
The Minimum Inhibitory Concentration was determined by the macro-tube dilution technique
following the guidelines of the National Committee for Clinical Laboratory Standards for
bacteria and for fungi [18]. The bacteria and fungi were maintained on nutrient broth medium
and malt extract broth medium, respectively. In this method 15 test tubes were utilized for
each microorganism, where the first one was charged with 2.0 mL of DMSO and 10 mg of
the tested compound. To the remaining tubes was added 1.0 mL of sterile broth medium.
Subsequently, 1.0 mL was transferred from the first tube to the second one, followed by
continuous dilutions in this manner to the 14th tube, discarding 1.0 mL from the latter. The
15th tube served as a control. Several colonies of tested culture were suspended to an
appropriate turbidity in 5.0 mL of broth medium. Further dilution by transferring 0.2 mL of
the suspension into 40 mL was done. 1.0 mL of the diluted culture suspension was then added
to each of the tubes. Finally, Incubation at 37 °C overnight for bacteria and 30 °C and 72 h
for fungi was performed. The tubes were examined for visible signs of microbial and fungal
growth, where the highest dilution without growth is the MIC.
References
[1] Y. A. Ammar, M.A. M. Sh. El-Sharief, M. M. Ghorab, Y. A. Mohamed, A. Ragab, S.
Y. Abbas, Cur. Org. Syn., 13 (2016) 466-475
[2] S.Y. Abbas, M.A.M.Sh. El-Sharief, W.M. Basyouni, I.M.I. Fakhr, E.W. El-Gammal,
Eur. J. Med. Chem. 64 (2013) 111-120.
[3] M.A.M.Sh. El-Sharief, S.Y. Abbas, K.A.M. El-Bayouki, E.W. El-Gammal, Eur. J.
Med. Chem. 67 (2013) 263-268.
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ACCEPTED MANUSCRIPT
[4] M.H. Helal, S.Y. Abbas, M.A. Salem, A.A. Farag, Y. A. Ammar, Med. Chem. Res. 22
(2013) 5598-5609
[5] Thomas, K. D.; Adhikari, A. V.; Telkar, S.; Chowdhury, I. H.; Mahmood, R.; Pal, N.
K.; Row, G.; Sumesh, E. Eur. J. Med. Chem. 2011, 46, 5283.
[6] Kategaonkar, A. H.; Shinde, P. V.; Kategaonkar, A. H.; Pasale, S. K.; Shingate, B. B.;
Shangare, M. S. Eur. J. Med. Chem. 2010, 45, 3142.
[7] Lilienkampf, A.; Mao, J.; Wan, B.; Wang, Y.; Franzblau, S. G.; Kozikowski, A. P. J.
Med.Chem. 2009, 52, 2109.
[8] Denny, W. A.; Wilson, W. R.; Ware, D. C.; Atwell, G. J.; Milbank, J. B.; Stevenson,
R. J.U.S. Patent 2006, 7064117.
[9] Nasveld, P.; Kitchener, S.; Kitchener, S. Trans. R. Soc. Trop. Med. Hyg. 2005, 99, 2.
[10] L.M. Fisher, X. Pan, New Antibiotic Targets, Methods In Molecular Medicine
142(2008),11-23
[11] H.H. Jardosh, M.P. Patel, Eur. J. Med. Chem. 65 (2013) 348-359.
[12] S.P. Satasia, P.N. Kalaria, D.K. Raval, Org. Biomol. Chem. 12 (2014) 1751-1758
[13] S. Singh Jadav, B. Nayan Sinha, B. Pastorino, X. de Lamballerie, R. Hilgenfeld, V.
Jayaprakash, Lett. Drug Des. Discov. 12 (2015) 292-301.
[14] A.A. Farag, M. F. El Shehry, S. Y. Abbas, A. A. Atrees, Y. A. Ammar, Z. Naturforsch.
B. 2015 (70) 519-526
[15] W. H. Perkin, R. Robinson, J. Chem. SOC.103 (1913) 1973
[16] P.V. Raghavan, Expert consultant, CPCSEA, OECD, guideline No. 420, 2000.
[17] Cooper, R. E. Analytical Microbiology, Ed. Kavangeh, F.W. Vol. 1&2, Academic
press,New York and London, 1972.
[18] NCCLS, National Committee for Clinical Laboratory Standards. Methods for dilution
antimicrobial susceptibility tests for bacteria that grow aerobically. Fourth edition,
Approved Standard, NCCLS, M7 - A4, 1997; NCCLS, National Committee for
Clinical Laboratory Standards. In Method M27 A2, 2nd ed.; Wayne, Ed.; NCCLS:
Pennsylvania, 2002; Vol. 22 (15), pp 1-29.
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ACCEPTED MANUSCRIPT
Figure captions:
Scheme 1: Syntheses of the chalcones 2 and 6a,b, and pyrazoline 3,4, 7a,b and 8a,b
derivatives. Reagents and reactions conditions: (a) 4-hydroxybenzaldehyde, DMF, K2CO3,
100 °C 6 h; (b) 4-methoxyacetophenone, ethanol, 10 % aq. NaOH, stirring 2 h; (c) hydrazine
hydrate, ethanol, reflux 4 h; (d) phenylhydrazine ethanol, reflux 6 h; (e) 4-
hydroxyacetophenone, DMF, K2CO3, reflux 12 h; (f) aldehydes (namely, 2-
chlorobenzaldehyde and 4-methoxybenzaldehyde), ethanol, 10 % aq. NaOH, stirring 2 h.
Scheme 2: Synthesis of pyrazole derivatives 10a-c; Reagents and reactions conditions: (a)
hydrazine hydrate, ethanol, reflux, 12 h; (b) formylpyrazoles, ethanol, reflux 3 h.
Scheme 3: Synthesis of pyrazole derivatives 11-13; reactions conditions: ethanol, reflux, 4 h.
Figure 1: General formula of the synthesized compounds 3,4, 7a,b and 8a,b
Figure 2: The comparison between the antibacterial and antifungal activities of synthesized
compounds 2-4, 7a,b, 8a,b and standard drugs against the used Gram-positive, Gram-
negative bacteria and fungi
Figure 3: The comparison between the antibacterial and antifungal activities of synthesized
compounds 10a-c and standard drugs against the used Gram-positive, Gram-negative bacteria
and fungi
Figure 4: General formula of the synthesized compounds 11a,b, 12a,b, 13a,b
Figure 5: The comparison between the antibacterial and antifungal activities of synthesized
compounds 11a,b, 12a,b, 13a,b and standard drugs
Figure 6: The comparison between the minimal inhibitory concentrations of compound 13b
and standard drugs against the used Gram-positive, Gram-negative bacteria and fungi
Table 1: Antimicrobial activity of the synthesized compounds against the pathological
organisms expressed as inhibition diameter zones in millimeters (mm) based on well
diffusion assay
Table 2: Minimum inhibitory concentration (µg/mL) of the more potent synthesized
compounds against the pathological organisms
- 18 -

ACCEPTED MANUSCRIPT
Table 1: Antimicrobial activity of the synthesized compounds against the pathological organisms expressed as inhibition diameter zones in
millimeters (mm) based on well diffusion assay
Compd.
No
2
Gram +ve bacteria
Gram -ve bacteria
K. pneumonia S. flexneri
Fungi
A. clavatus
11.5±0.42
12.8±0.53
14.5±0.12
17.5±0.28
14.2±0.52
0.0
S. aureus
8.7 ±0.5
16.2 ±0.5
12.1 ±0.3
23.9 ±0.4
13.1±0.3
14.8±0.3
29.0±0.2
22.2±0.5
24.5±0.6
20.3±0.6
S. epidermidis B. subtilis
P. vulgaris
0.0
A. fumigatus
10.7±0.62
15.6±0.21
16.2±0.24
21.4±0.36
13.5±0.54
12.3±0.52
23.5±0.36
17.5±0.35
21.5±0.36
20.5 ± 0.22
16.8 ± 025
16.3 ± 0.44
15.7 ± 0.33
18.7 ± 0.11
12.3 ± 0.25
20.9 ± 0.25
-----
C. albicans
0.0
10.6±0.4
18.6±0.7
13.11±0.1
25.3±0.3
14.6±0.5
0.0
0.0
7.2±0.16
0.0
0.0
19.4±0.35
0.0
16.2±0.52
13.5±0.55
23.6±0.17
14.3±0.32
12.4±0.63
24.5±0.38
20.2±0.18
21.4±0.76
15.4±0.64
14.4±0.33
23.6±0.32
14.3±0.42
0.0
11.6±0.35
11.6±0.52
18.5±0.24
12.1±0.34
9.3±0.24
23.5±0.19
19.6±0.45
24.9±0.43
22.1 ± 0.15
20.4 ± 0.63
19.8 ± 0.25
16.8 ± 0.34
20.3 ± 0.27
15.2 ± 0.58
24.8 ± 0.58
-----
3
15.92±0.76
22.8±0.28
16.2±0.55
13.3±0.50
26.1±0.24
21.2±0.25
22.9±0.63
17.6 ± 0.58
4
24.2±0.61
13.7±0.53
16.4±0.25
28.7±0.24
23.2±0.31
27.6±0.34
7a
7b
8a
26.2±0.3
23.4±0.5
25.7±0.6
20.7 ± 0.2
23.3±0.32
20.1±0.33
21.8±0.34
18.3 ± 1.2
22.9±0.35
18.4±0.35
19.8±0.25
18.3 ± 0.26
18.3 ± 0.44
18.6 ± 0.58
15.9 ± 0.25
19.3 ± 0.23
13.2 ± 0.25
22.3 ± 0.25
-----
8b
10a
10b
10c
11a
11b
12a
12b
13a
13b
22.4 ± .036 16.2 ± .058
19.2 ± 0.2 20.6 ± 0.23 20.9 ± 0.63 11.6 ± 0.43
15.7 ± 0.56 15.9 ± 0.77
15.9 ± 0.37 16.8 ± 0.37
15.3 ± 0.53 16.2 ± 0.53
20.3± 0.5
18.9 ± 0.1
15.8± 0.4
10.3 ± 0.5
21.6 ± 0.2
17.3 ± 0.6
16.2 ± 0.2
17.8 ± 0.2
11.6 ± 0.6
22.3 ± 0.3
25.4±0.2
-----
20.2 ± 0.44 13.6 ± 0.37
19.8 ± 0.42 12.3 ± 0.53
19.8 ± 0.22
13.3 ± 0.72
0
0
0
0
0
0
25.8 ± 0.25 20.6 ± 0.25
21.6 ± 0.19 23.2 ± 0.42
Ampicillin 28.9±0.14
Gentamycin -----
Amphotericin B -----
34.6±0.35
-----
-----
23.4±0.3
-----
-----
-----
26.3±0.15
-----
24.8±0.24
-----
-----
-----
-----
-----
-----
23.7±0.10
21.9±0.12
26.4±0.20

ACCEPTED MANUSCRIPT
Table 2: Minimum inhibitory concentration (µg/mL) of the more potent synthesized compounds against the pathological organisms
Gram +ve bacteria
S. aureus S. epidermidis B. subtilis
Gram -ve bacteria
Fungi
Compd. No
P. vulgaris
0.97
9.9
K. pneumonia
1.95
S. flexneri
1.95
0.48
7.81
3.9
A. fumigatus A. clavatus
C. albicans
1.95
0.48
7.81
3.9
0.97
0.24
3.9
0.97
0.24
3.9
1.95
0.06
1.97
0.97
0.49
0.98
1.95
-----
0.12
0.007
-----
-----
7.81
1.95
7.81
15.63
0.98
15.63
31.25
7.81
0.98
-----
15.63
3.9
7a
8b
3.9
7.81
3.9
3.9
15.63
7.81
7.81
7.8
10a
0.97
1.95
3.9
3.9
3.9
10b
0.98
0.98
15.63
-----
0.49
0.48
-----
-----
31.25
500
7.81
7.81
31.25
15.63
-----
0.49
1.95
1.95
1.95
0.12
-----
10c
31.25
31.25
-----
11a
1.95
-----
0.49
0.06
-----
125
3.9
11b
-----
0.98
-----
1.95
-----
7.81
0.49
-----
-----
1.95
12b
0.49
0.12
-----
13b
Ampicillin
Gentamycin
-----
0.24
0.48
-----
-----
-----
Amphotericin B -----
-----
0.97
0.48

ACCEPTED MANUSCRIPT
Scheme 1: Syntheses of the chalcones 2 and 6a,b, and pyrazoline 3,4, 7a,b and 8a,b derivatives. Reagents and reactions conditions: (a) 4-
hydroxybenzaldehyde, DMF, K2CO3, 100 °C 6 h; (b) 4-methoxyacetophenone, ethanol, 10 % aq. NaOH, stirring 2 h; (c) hydrazine hydrate,
ethanol, reflux 4 h; (d) phenylhydrazine ethanol, reflux 6 h; (e) 4-hydroxyacetophenone, DMF, K2CO3, reflux 12 h; (f) aldehydes (namely, 2-
chlorobenzaldehyde and 4-methoxybenzaldehyde), ethanol, 10 % aq. NaOH, stirring 2 h.
N
Cl
R
N
N
O
CHO
b
c or d
OCH3
a
N
O
OCH3
N
O
N
1
O
O
3,
4,
R = H
2
R = Ph
R
O
O
N
N
R1
R1
CH3
c or d
e
f
N
N
O
N
O
5
6a R = 2-Cl
6b R = 4-OCH3
7a R = H, R1 = 2-Cl
7b R = H, R1 = 4-OCH3
8a R = Ph, R1 = 2-Cl
8b
R = Ph, R1 = 4-OCH3
- 1 -

ACCEPTED MANUSCRIPT
Scheme 2: Synthesis of pyrazole derivatives 10a-c; Reagents and reactions conditions: (a)
hydrazine hydrate, ethanol, reflux, 12 h; (b) formylpyrazoles, ethanol, reflux 3 h.
R
a
b
NH2
N
N
N
N
N
N
Cl
H
H
N
9
N
10a
10b
10c,
, R = H
, R = 4-Cl Ph
R = 4-CH3
Scheme 3: Synthesis of pyrazole derivatives 11-13; reactions conditions: ethanol, reflux, 4 h.
NC
X
H3C
OEt
N
N
N
CH3
H2N
X
NH2
11a
11b
X = CN
X = COOEt
N
N
H
NC
X
9
NC
CN
H3CS
SCH3
N
N
N
SCH3
H
X
H2N
X
12a
12b
X = CN
X = COOEt
N
N
N
X
H2N
CN
X = 3-Cl
X = 2,4-Cl2
13a
13b
- 2 -

ACCEPTED MANUSCRIPT
Figure 1: General formula of the synthesized compounds 3,4, 7a,b and 8a,b
R1
N
N
R2
R3
3,
4,
R1 = H, R2 = 2-phenoxyquinoline, R3 = 4-methoxyphenyl
R1 = Ph, R2 = 2-phenoxyquinoline, R3 = 4-methoxyphenyl
7a,
7b,
8a,
8b,
R1 = H, R2 = 2-chlorophenyl
R1 = H, R2 = 4-methoxyphenyl
R1 = Ph, R2 = 2-chlorophenyl
R1 = Ph, R2 = 4-methoxyphenyl
R3 = 2-phenoxyquinoline,
R3 = 2-phenoxyquinoline,
R3 = 2-phenoxyquinoline,
R3 = 2-phenoxyquinoline,
Figure 2: The comparison between the antibacterial and antifungal activities of synthesized
compounds 2-4, 7a,b, 8a,b and standard drugs against the used Gram-positive, Gram-
negative bacteria and fungi.
35
S. aureus
30
S. epidermidis
25
20
15
10
5
B. subtilis
P. vulgaris
K. pneumonia
S. flexneri
A. fumigatus
A. clavatus
C. albicans
0
Compound No.
- 3 -

ACCEPTED MANUSCRIPT
Figure 3: The comparison between the antibacterial and antifungal activities of synthesized
compounds 10a-c and standard drugs against the used Gram-positive, Gram-negative bacteria
and fungi.
35
S. aureus
30
S. epidermidis
25
B. subtilis
P. vulgaris
20
15
10
5
K. pneumonia
S. flexneri
A. fumigatus
A. clavatus
C. albicans
0
10a
10b
10c
Standard
Compound No.
Figure 4: General formula of the synthesized compounds 11a,b, 12a,b, 13a,b
N
N
N
R
H2N
X
11a X = CN, R = CH3,
11b
12a X = CN, R = SCH3,
13a X = CN, R = 3-Cl-C6H4
13b
X = CN, R = 2,4-Cl2-C6H3
12b
X = COOEt, R = CH3,
X = COOEt, R = SCH3,
- 4 -

ACCEPTED MANUSCRIPT
Figure 5: The comparison between the antibacterial and antifungal activities of synthesized
compounds 11a,b, 12a,b, 13a,b and standard drugs
35
S. aureus
30
S. epidermidis
25
B. subtilis
20
P. vulgaris
15
K. pneumonia
10
S. flexneri
5
0
A. fumigatus
A. clavatus
C. albicans
Compund No.
Figure 6: The comparison between the minimal inhibitory concentrations of compound 13b
and standard drugs against the used Gram-positive, Gram-negative bacteria and fungi
2.5
2
1.5
1
0.5
0
13b
Standard
- 5 -

ACCEPTED MANUSCRIPT
‹ Synthesis of chalcones.
‹ Using the chalcones for synthesizing variously substituted pyrazoles.
‹ Synthesis of 2-hydrazinylquinoline.
‹ Using the 2-hydrazinylquinoline for synthesizing variously substituted pyrazoles.
‹ The antimicrobial activity assay was determined.