Synthesis of some 3-(Arylalkylthio)-4-alkyl/aryl-5-(4-aminophenyl)-4H-1,2, 4-triazole derivatives and their anticonvulsant activity

Article abstract of DOI:10.1016/j.farmac.2004.07.005

A series of novel 3-{[(substituted phenyl)methyl]thio}-4-alkyl/aryl-5-(4- aminophenyl)-4H-1,2,4-triazoles 11-20 and several related Schiff's bases, 3-{[(substituted phenyl)-methyl]thio}-4-alkyl/aryl-5-{[[(substituted phenyl/5-nitro-2-furyl)methylene]amino

Full text of DOI:10.1016/j.farmac.2004.07.005

IL FARMACO 59 (2004) 893–901
http://france.elsevier.com/direct/FARMAC/
Original article
Synthesis of some
3-(Arylalkylthio)-4-alkyl/aryl-5-(4-aminophenyl)-4H-1,2,4-triazole
derivatives and their anticonvulsant activity
a,
a
a
b
˙
Ilkay Küçükgüzel *, Sq. Güniz Küçükgüzel , Sevim Rollas , Gülten Ötük-Sanıs¸ ,
c
d
d
e
˙
Osman Özdemir , Ibrahim Bayrak , Tuncay Altug˘ , James P. Stables
a Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Marmara University, Tıbbiye Cad. No. 49, Haydarpasa, 34668 Istanbul, Turkey
b Departments of Pharmaceutical Microbiology, University of Istanbul, Faculty of Pharmacy, 34452-Beyazit, Istanbul, Turkey
c Pharmacology, University of Istanbul, Faculty of Pharmacy, 34452-Beyazit, Istanbul, Turkey
d Department of Experimental Animals, University of Istanbul, Cerrahpasa Medical Faculty, Cerrahpasa, Istanbul, Turkey
e Epilepsy Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
Received 5 May 2003; received in revised form 24 June 2004; accepted 2 July 2004
Available online 15 September 2004
Abstract
A series of novel 3-{[(substituted phenyl)methyl]thio}-4-alkyl/aryl-5-(4-aminophenyl)-4H-1,2,4-triazoles 11–20 and several related
Schiff’s bases, 3-{[(substituted phenyl)-methyl]thio}-4-alkyl/aryl-5-{[[(substituted phenyl/5-nitro-2-furyl)methylene]amino]-phenyl}-4H-
1,2,4-triazoles 21–31 were synthesized for evaluation of their biological properties. Structures of the synthesized compounds were confirmed
by the use of their spectral data besides elemental analysis. All compounds were evaluated for their anticonvulsant activity by maximal
electroshock (MES), subcutaneous pentylenetetrazole (scPTZ) and neurotoxicity (NT) screens. A number of triazole derivatives, exhibited
protection after intraperitoneal administration at the dose of 100 and 300 mg/kg in one or both models employed. Compounds 12, 13 and 14
were subjected to oral MES screening in rats at 30 mg/kg and were observed to protect 50% of the animals employed in the experiment.
Antimicrobial and antituberculosis activity of these compounds 11–31 were also screened. Some of the tested compounds showed marginal
activity against M. tuberculosis H37 Rv.
© 2004 Published by Elsevier SAS.
Keywords: 1,2,4-Triazoles; Pentylenetetrazole; Maximal electroshock; Anticonvulsant activity; Neurotoxicity
1. Introduction
anticonvulsant properties [1–9], led us to synthesize some
new compounds possessing analogous structures in order to
obtain more potent anticonvulsant agents.
Epilepsy is neurological disorder characterised by unpro-
voked seizures that affects at least 50 million people world-
wide. There is continuing demand for new anticonvulsant
agents as it has not been possible to control every kind of
seizure with the currently available antiepileptic drugs. The
anticonvulsant drug, Loreclezole is a positive modulator of
GABAA receptors containing a b2 or b3 subunit [1]. Benzo-
diazepine agonist, Estazolam is an anticonvulsant drug,
which contains triazolobenzodiazepine ring [2]. The fact that
several 1,2,4-triazole derivatives have been proven to exhibit
In addition, certain 4-alkyl/aryl-5-(4-aminophenyl)-2,4-
dihydro-3H-1,2,4-triazole-3-thiones, synthesized in our
laboratory, possess some antifungal properties [10] is star-
* Corresponding author. Tel.: +90-216-349-12-16;
fax: +90-216-345-29-52.
˙
E-mail address: ikucukguzel@marmara.edu.tr (I. Küçükgüzel).
0014-827X/$ - see front matter © 2004 Published by Elsevier SAS.
doi:10.1016/j.farmac.2004.07.005

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894
ting compound in this study and N-allyl-N′-[4-
[3-[(2,4-dichlorobenzyl)thio]-4-methyl-4H-1,2,4-triazole-5-
yl]phenyl]thiourea, inhibited the growth of Mycobacterium
tuberculosis H37 Rv at 6.25 µg/ml [11] is compound which
contains 1,2,4-triazole ring.
In view of the above observations, the synthesis of novel
1,2,4-triazole derivatives starting from arylthiosemicarbazi-
des were aimed at investigating antimicrobial and antimyco-
bacterial properties in addition to their anticonvulsant activi-
ties. Several Schiff’s bases in which primary amino group
was masked were also synthesized to observe the contribu-
tion of this function to pharmacological activity.
The synthesized compounds were characterized by their
elemental analyses, m.p.’s and IR, H-NMR and EI-mass
1
spectral data. These physical and spectral data of the synthe-
sized compounds are presented in Tables 1–3. The IR spectra
of compounds 11–20 showed NH asymmetric and symmetric
stretching bands of primary amine function at 3460–
3440 cm–1 and 3350–3305 cm–1, respectively (Table 2).
These bands were not detectable for compounds 21–31,
demonstrating the disappearance of this group (Table 3). The
C=N stretching bands of compounds 11–31 appeared at
1650–1600 cm–1 region [14]. Strong absorption bands at
1520 and 1350 cm–1 observed in the IR spectra of com-
pounds 16 and 25 were attributed to the asymmetric and
symmetric NO2 stretching vibrations, respectively.
1
2. Chemistry
The exhibited chemical shifts obtained from H-NMR
spectra were all supported the proposed structures of 5, 10
and 11–31. The 1H-NMR spectra of compounds 11–18,
which were taken in CDCl3, displayed the NH2 protons at
3.81–4.01 ppm [15]. These signals were observed to be
shifted to 5.45 and 5.43 ppm [10] for compounds 19 and 20,
respectively. This paramagnetic shift could be attributed to
the use of DMSO-d6 as the solvent. The triazoline CS-NH
proton of compound 10 resonated at 13.78 ppm, probably
because of strong intermolecular hydrogen bonding, as re-
ported earlier [15–17]. In the 1H-NMR spectra of 11–31, the
lack of signals arising from triazoline CS-NH function at
13.00–14.00 ppm, observed with 6–10 [15–17], provided the
evidence for the formation of thioether function. Another
support for the structures of these compounds was obtained
by the presence of resonances arising from benzylic protons
at 4.05–4.64 ppm [11]. Compounds 21–31 containing an
imine function exhibited no signals at regions, which are
attributable to any NH2 protons, showing the disappearance
of aromatic primary amine groups. In addition, azomethine
protons in 21–31 resonated at 7.97–8.72 ppm as expected
Synthetic route to 11–31 is presented in Scheme 1. 1-[4-
(Benzoylamino)benzoyl]-4-alkyl/aryl thiosemicarbazides
1–5 were obtained by the reactions of alkyl/aryl isothiocya-
nates with 4-(benzoylamino)benzoic acid hydrazide [12]
whose synthesis was previously described [13]. Cyclodehy-
dration of 1–5 was then performed in alkaline medium to
give 6–10. This procedure not only provided 1,2,4-triazoline-
3-thione ring closure, but also gave rise to hydrolytic clea-
vage of the benzoyl moiety present at 1–5. 3-Alkylthio deri-
vatives of 6–10 were synthesized in yields ranging between
45% and 88% by the action of several benzyl chlorides
on 5-(4-aminophenyl)-4-alkyl/aryl-2,4-dihydro-3H-1,2,4-
triazole-3-thiones 6–10 in the presence of strong alkali. Aro-
matic primary amine function, present at 6–10 was observed
not to be alkylated although no protective precautions were
taken during the syntheses of 11–20 as evidenced by spectral
investigations. Condensation of 11–20 with appropriate alde-
hydes finally furnished the Schiff’s base derivatives 21–31 in
yields ranging between 54% and 87%.
Scheme 1
gAcOH, reflux.
. Synthetic route to 11–31. Reagents and conditions: (a) R1–NCS/EtOH, reflux; (b) NaOH (2N), reflux; (c) Ar–CH2–Cl, NaOH/EtOH; (d) Ar–CHO,

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895
Table 1
Some physicochemical characteristics of 11–31
Compound R1
R2
R3
Ar
Formula
M.W.
Yield M.p.
Analysis (calculated/found)
(g mol–1) (%) (°C)
C
H
N
11
CH3
Cl
H
Cl
H
–
–
–
C
C
C
16H14Cl2N4S
365.281 81
296.391 75
391.318 45
92–5
125–8
61–4
50.14/49.78 4.21/4.02
64.84/64.55 5.44/5.28
52.82/51.66 4.93/4.39
14.62/13.76
18.90/18.84
13.69/12.77
12a
13
CH3
16H16N4S
CH2–
Cl
Cl
18H16Cl2N4S·H2O
CH=CH2
CH2–
CH=CH2
C6H5
14
H
H
–
C
18H18N4S
322.428 88
84–7
183
67.05/66.74 5.63/5.46
57.80/57.15 3.93/3.81
17.38/17.12
15
16
17
18
19
20
21
Cl
H
Cl
NO2
H
–
C
C
C
C
C
C
C
21H16Cl2N4S·1/2H2O 427.350 87
12.84/12.33
17.36/17.06
15.63/15.82
12.93/12.54
12.69/12.91
15.04/14.82
10.73/10.52
C5H5
–
21H17N5O2S
21H18N4S
403.458 50
358.461 88
433.398 72
441.377 74
372.487 76
522.277 65
210–3 (dec) 62.52/61.98 4.25/4.16
C6H5
H
–
205–8
171–4
178–80
162–5
161–5
70.36/70.15 5.06/5.06
58.19/57.82 5.12/4.98
59.87/59.00 4.11/4.07
70.94/70.02 5.41/5.26
52.89/52.52 3.09/2.97
C6H11
Cl
Cl
Cl
H
–
21H22Cl2N4S
22H18Cl2N4S
22H20N4S
C6H4CH3 (4) Cl
–
C6H4CH3 (4)
CH3
H
–
Cl
Cl
C6H3Cl2
(2,6)
23H16Cl4N4S
22
23
24
CH3
Cl
Cl
Cl
Cl
Cl
Cl
C6H4F (4)
C6H4OH (4)
C6H4F (4)
C
C
C
23H17Cl2FN4S
23H18Cl2N4S
25H19Cl2FN4S
471.378 79
469.387 68
497.415 54
140–5
58.61/57.29 3.63/3.42
11.89/11.60
11.94/11.74
11.25/11.20
CH3
180–4 (dec) 58.85/57.69 3.86/3.78
141–5 60.37/59.89 3.85/3.71
CH2–
CH=CH2
C6H5
C6H5
25b
26
Cl
Cl
Cl
Cl
5–nitro–furyl
C6H3Cl2
C26H17Cl2N5O3S
28H18Cl4N4S
550.416 50
584.346 75
210–3 (dec) 62.52/61.98 4.25/4.16
17.36/17.06
9.59/9.27
C
171–4
57.55/56.82 3.10/2.88
(2,6)
27
28
29
30
31
C6H5
Cl
Cl
Cl
Cl
H
C6H4F (4)
C6H4Cl (4)
C6H4OH (4)
C6H4Cl (4)
C6H4OH (4)
C
C
C
C
C
28H19Cl2FN4S·1/2H2O 533.447 79
206–8
61.99/61.98 3.72/3.41
61.76/61.37 3.75/3.87
10.33/10.38
9.93/10.28
10.27/10.70
11.32/11.75
11.75/11.86
C6H4CH3 (4) Cl
C6H4CH3 (4) Cl
29H21Cl3N4S
29H22Cl2N4OS
29H23ClN4S
29H24N4OS
563.928 86
545.483 87
495.039 83
476.593 75
217–21
227–32 (dec) 63.85/62.94 4.06/3.35
C6H4CH3 (4)
H
197–8
245–8
70.36/70.12 4.68/4.23
73.08/72.26 5.07/5.39
C6H4CH3 (4)
H
H
a EI–MS (70 eV, m/z) of compound 12: 296(M+), 281, 264, 263, 219, 206, 205, 187, 134, 133, 132, 119, 118, 106, 92, 91(100%), 88, 77.
b EI–MS (70 eV, m/z) of compound 25: 551[(M+2)+], 549(M+), 516, 514, 484, 482, 391, 390, 377, 375, 241, 219, 217, 195, 193, 191, 161, 159, 150, 149, 138,
129, 127, 125, 118, 92, 91, 89, 77, 73.
[18]. Chemical shifts of phenolic protons were detected at
9.33–10.13 ppm with compounds 23, 29 and 31 [19]. The
remaining protons were also observed at the expected re-
gions (Tables 2 and 3).
1,2,4-triazoles 11–20 and several related Schiff’s bases,
3-[[(substituted phenyl)methyl]thio]-4-alkyl / aryl-5-[4-
[(aryl methylene)amino]phenyl]-4H-1,2,4-triazoles 21–31
were carried out according to the Anticonvulsant Screening
Program (ASP) protocol [20].
In the EI-mass spectra of two selected prototypes, 12 and
25, the existing molecular ions confirmed the molecular
weights of these compounds. In case of compound 25,
EI-MS also displayed the (M+2)+ ions arising from the iso-
topic composition of either M+ or fragment ions. Main frag-
mentation of 12 appeared by the cleavage of exocyclic S–C
bond yielding the tropylium ion as base peak at m/z 91 and
the fragment ion C9H9N4S+(m/z 205), whereas direct loss of
Cl. radical from the molecular ion of 25 afforded the frag-
ment C26H17ClN5O3S+(m/z 514/516) as the most abundant
ion.
Testing performed via these protocols generated profiles
of potential anticonvulsant activity after intraperitoneal (i.p.)
injections using both electrical and chemical test models.
The electrical model employed was maximal electroshock
seizure (MES) test. The current (60 Hz) utilized in these
experiments is at least five times the threshold required to
produce a hindlimb extension. In mice, 50 mA is utilized and
in rat 150 mA is administered via corneal electrodes using an
anesthetic/electrolyte solution. The chemical model em-
ployed in these experiments was the subcutaneous pentyle-
netetrazole (scPTZ) seizure threshold test. Minimal motor
impairment was measured by the rotorod (neurotoxicity, NT)
test.All of the above experiments were carried out using male
albino CF #1 mice weighing between 18–25 g. In addition to
the testing models noted above, selected compounds 12, 13,
and 14 were also administered orally to rats and again,
3. Results and discussion
Initial anticonvulsant evaluation of 3-[[(substituted
phenyl)methyl]thio]-4-alkyl / aryl-5-(4-aminophenyl)-4H-

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Table 2
IR and 1H-NMR spectral data of 11–20
Compound IR [KBr, m(cm–1)]
1H-NMR [d(ppm)]
11
12
13
3460, 3320 (NH), 3070–3030, 2950 (CH), 1615, 1490,
1470 (C=N, C=C, NH), 1300, 1240 (C–N), 705 (C–S)
3.39 (s.3H, >N–CH3); 3.95 (b, 2H, Ar–NH2); 4.49 (s, 2H, –S–CH2); 6.76 (d, 2H,
o–NH2, J = 9 Hz); 7.14–7.16 (dd, 1H, H5, J = 8.1 Hz); 7.37 (d, 1H, H6, J = 8.1 Hz);
7.37 (d, 2H, m–NH2, J = 8.5 Hz); 7.42 (d, 1H, H3, J = 2 Hz)
3450, 3310 (NH2), 3060–3030, 2950 (C–H), 1615,
1490, 1470 (C=C, C–N, N–H), 1300, 1240 (C–N), 700
(C–S)
3.23 (s, 3H, –CH3), 3.96 (b, 2H, –NH2), 4.35 (s, 2H, –CH2), 6.73 (d, 2H, o–NH2,
J = 8.6 Hz), 7.27 (s, 5H, –C6H5), 7.35 (d, 2H, m-NH2, J = 8.6 Hz)
3440, 3340 (NH), 3070–3040, 2920 (CH), 1615, 1475,
1455 (C=N, C=C, NH), 1300, 1240 (C–N), 725 (C–S)
3.93 (b, 2H, Ar–NH2); 4.39–4.41(m, 2H, >N–CH2); 4.55 (s, 2H, –S–CH2); 4.91(d,
1H, =C<H, J = 17.2 Hz); 5.23 (d, 1H, =C<H, J = 10.4 Hz); 5.86 (m, 1H, –CH=);
6.73 (d, 2H, o–NH2, J = 8.5 Hz); 7.15–7.16 (dd, 1H, H5, J = 8.4 Hz); 7.41 (d, 1H,
H3, J = 1.9 Hz); 7.45 (d, 2H, m-NH2, J = 8.1 Hz); 7.63 (d, 1H, H6, J = 8.6 Hz)
3.92 (b, 2H, Ar–NH2); 4.33–4.35 (m, 2H, >N–CH2); 4.46 (s, 2H, –S–CH2); 4.92 (d,
1H, =C<H, J = 17.2 Hz); 5.23 (d, 1H, =C<H, J = 10.5 Hz); 5.78 (m, 1H, –CH=);
6.73 (d, 2H, o-NH2, J = 8.6 Hz); 7.30–7.36 (m, 5H, Ar–H); 7.40 (d, 2H, m-NH2,
J = 8.5 Hz)
14
3460, 3335 (NH), 3040, 2920 (CH), 1630, 1615, 1490,
1460, 1425 (C=N, C=C, NH), 1300, 1250 (C–N),
700 (C–S)
15
16
17
18
3440, 3350 (NH), 3060-3030, 2850 (CH), 1635, 1615,
1500, 1485, 1450 (C=N, C=C, NH), 1330, 1295,
1250 (C–N), 700 (C–S)
3.82 (b, 2H, Ar-NH2); 4.53 (s, 2H, –S–CH2); 6.54 (d, 2H, o–NH2, J = 8.5 Hz);
7.10–7.12 (dd, 1H, H5, J = 8 Hz); 7.19 (d, 1H, m-NH2, J = 8.7 Hz); 7.17–7.21 and
7.42–7.48 (m, 5H, Ar–H); 7.36 (d, 1H, H3, J = 2 Hz); 7.57(d, 1H, H6, J = 8.3 Hz)
3.83 (b, 2H, Ar–NH2); 4.53 (s, 2H, –S–CH2); 6.53 (d, 2H, o-NH2, J = 8.6 Hz);
7.11–7.14 and 7.45–7.50 (m, 5H, Ar–H); 7.18 (d, 2H, m–NO2, J = 8.6 Hz); 7.58 (d,
2H, m-NH2, J = 8.6 Hz); 8.14 (d, 2H, o–NO2, J = 8.6 Hz)
3450, 3340 (NH), 3040, 2940 (CH), 1650, 1620, 1500,
1450, 1430 (C=N, C=C, NH), 1520 (NO2), 1350 (NO2),
1320, 1235 (C–N), 700 (C–S)
3440, 3350 (NH), 3035, 2930–2840 (CH), 1630, 1615,
1500, 1485, 1460, 1450, 1430 (C=N, C=C, NH), 1295–
1240 (C–N), 705 (C–S)
3.81 (b, 2H, Ar–NH2); 4.46 (s, 2H, –S–CH2); 6.53 (d, 2H, o–NH2, J = 8.6 Hz); 7.34
(d, 2H, m–NH2, J = 8.0 Hz); 7.07, 7.19, 7.27 and 7.44 (m, 10H, Ar–H)
3460, 3305 (NH), 3070–3040, 2940-2865 (CH), 1645,
1620, 1490, 1450, 1430 (C=N, C=C, NH), 1310–
1250 (C–N), 710 (C–S)
1.16–2.06 (m, 10H, cyclohexyl –CH2–); 3.94–4.01 (b, 3H, Ar–NH2 and cyclohexyl
–CH<); 4.64 (s, 2H, –S–CH2); 6.76 (d, 2H, o–NH2, J = 8.5 Hz); 7.17–7.19 (dd, 1H,
H5, J = 8.2 Hz); 7.26 (d, 2H, m–NH2, J = 8.4 Hz); 7.42 (d, 1H, H3, J = 2 Hz); 7.53
(d, 1H, H6, J = 8.1 Hz)
19
20
3319, 3214 (NH), 3036 (CH), 1609, 1513, 1471,
1447 (C=N, C=C, NH), 1310–1250 (C–N), 735 (C–S)
3325, 3203 (NH), 3035 (CH), 1609, 1540, 1513,
1495 (C=N, C=C, NH), 1295–1240 (C–N), 735 (C–S)
2.37 (s, 3H, –CH3); 4.38 (s, 2H, –S–CH2); 5.45 (s, 2H, Ar–NH2); 6.44–7.59 (m,
11H, Ar–H)
2.36 (s, 3H, –CH3); 4.34 (s, 2H, –S–CH2); 5.43 (s, 2H, Ar-NH2); 6.44–7.33 (m,
11H, Ar–H)
examined in the MES screen. The 6 Hz test, a measure of
protection against induced focal seizures was carried out in
mice for compounds 11, 15, 24 and 28.
21–31, introduction of an aryl group to the fourth position of
the triazole ring in place of alkyl groups, resulted in a loss of
protection from PTZ-induced death.
In addition to experiments carried out in CF#1 mice, a
second species was also used. In these experiments, male
balb/c mice weighing between 20–30 g, were utilized in the
pentylenetetrazole model designed to assess both seizure
protection and mortality percentages. The data for the latter
experiments was performed in collaboration with Depart-
ment of Pharmacology, University of Istanbul, Faculty of
Pharmacy and Department of Experimental Animals, Uni-
versity of Istanbul, Cerrahpasa Medical Faculty. The infor-
mation collected is reported in Table 4. The data were recor-
ded over a 24 h period.
Anticonvulsant evaluations of compounds 11–31 in mice
i.p. MES, scPTZ and NT screens are summarized in Table 5
together with the literature data on standard drugs used
[21–23]. No mortality was detected with 18, 21, 23 and 24;
whereas 11, 14, 15, 17 and 22 provided survival rates ranging
from 80% to 90%, in the scPTZ test using the balb/c mouse
strain. However, compounds 16, 27 and 30 afforded no pro-
tection against PTZ-induced seizure and deaths. From the
data presented in Table 5, it can be concluded that com-
pounds 11–20, bearing a primary amine function, produced a
higher survival score compared to the Schiff’s bases 21–31 in
which this function is masked. As is shown with compounds
In order to reveal potential anticonvulsant profiles of the
synthesized compounds, the scPTZ and MES models were
employed according to the anticonvulsant drug development
(ADD) protocols [20]. The results are shown in Table 4.
Compounds 12, 13, 14, 17 and 20 were active in the MES test
at a dose of 300 mg/kg. This is indicative of their ability to
prevent seizure spread. At a dose level of 100 mg/kg, com-
pounds that showed protection in fifty percent or more of the
tested mice were: 12 (0.5 h), 13 (0.5 h, 4 h) and 14 (0.5 h).
The remaining compounds were found to be devoid of pro-
tective activity in the MES test. But, only one of these,
compound 29 showed signs of neurotoxicity at the doses and
times recorded. The toxic effects were observed for com-
pound 29 after 4 h using a dose of 300 mg/kg. Compounds
administered that resulted in the inability of mice to grasp
rotorod were 11 (300 mg/kg, 0.5 h, 4 h), 12 (300 mg/kg, 4 h)
and 13 (100 mg/kg, 0.5 h, 4 h). Mice lost their righting reflex
after administration of compounds 12 (300 mg/kg, 0.5 h), 13
(300 mg/kg, 0.5 h, 4 h) and 14 (300 mg/kg, 0.5 h, 4 h).
Only compounds 11 (300 mg/kg, 4 h), 12 (300 mg/kg,
0.5 h) and 13 (100 mg/kg, 0.5 h, 4 h) showed protection in the
scPTZ test whilst 14–31 were completely inactive using this
model.

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897
Table 3
IR and 1H-NMR spectral data of 21–31
Compound IR [KBr, m(cm–1)]
1H-NMR [d(ppm)]
21
2900 (CH), 1640, 1610, 1590, 1560 1480, 1430,
1410 (C=N, C=C), 1250 (C–N), 715 (C–S)
3.45 (s, 3H, >N–CH3); 4.55 (s, 2, –S–CH2); 7.17–7.19 (dd, 1H, H5, J = 8.2 Hz);
7.32–7.34 and 7.43–7.46 (m, 5H, Ar–H); 7.38 (d, 2H, o–N=CH, J = 8.4 Hz); 7.68
(d, 2H, m–N=CH, J = 8.4 Hz); 8.72 (s, 1H, –CH=N–)
22
2850 (CH), 1630, 1590, 1510, 1480, 1410 (C=N, C=C),
1290 (C–N), 710 (C–S)
3.47 (s, 3H, >N–CH3); 4.54 (s, 2H, –S–CH2); 7.16–7.19 (dd, 1H, H5, J = 8.2 Hz);
7.21 (t, 2H, o–F, J = 8.6 Hz); 7.31(d, 2H, o-N=CH, J = 8.1 Hz);7.43 (d, 1H, H6,
J = 8.1 Hz); 7.44 (d, 1H, H3, J = 2.1 Hz); 7.65 (d, 2H, m–N=CH, J = 8.5 Hz); 7.95
(t, 2H, m–F, 8.7 Hz); 8.46 (s, 1H, –CH=N–)
23
24
2890 (CH), 1630, 1590, 1570, 1520, 1480, 1430 (C=N,
C=C), 1290, 1245 (C–N), 705 (C–S)
3.14 (s, 3H, >N–CH3); 4.13 (s, 2H, –S–CH2); 6.57 (d, 2H, o–OH, J = 8.5 Hz);
6.83–6.85 (dd, 1H, H5, J = 8.2 Hz); 6.93 (d, 2H, m–OH, J = 8.4 Hz); 7.05 (d, 2H,
o–N=CH, 8.4 Hz); 7.07 (d, 1H, H3, J = 2 Hz); 7.26 (d, 1H, H6); 7.42 (d, 2H,
m–N=CH, J = 8.5 Hz); 8.04 (s, 1H, –CH=N–); 9.33 (s, 1H, Ar–OH)
4.46–4.47 (m, 2H, >N–CH2); 4.59 (s, 2H, –S–CH2); 4.93 (d, 1H, =C<H,
J = 17.2 Hz); 5.29 (d, 1H, =C<H, J = 10.4 Hz); 5.85 (m, 1H, =CH); 7.17–7.19 (dd,
1H, J = 8.3 Hz); 7.21 (d, 2H, o–F, J=8.6 Hz); 7.30 (d, 2H, o–N=CH); 7.42 (d, 1H,
H3, J = 2 Hz); 7.49 (d, 1H, H6, J = 8.3 Hz); 7.65 (d, 2H, m–N=CH, J = 8.4 Hz);
7.94 (d, 2H, m–F, J = 8.6 Hz); 8.45 (s, 1H, –CH=N–)
3080 (CH), 1630, 1605, 1590, 1510 1485, 1460, 1440,
1415 (C=N, C=C), 1295, 1250 (C–N), 710 (C–S)
26
27
28
29
30
31
3080 (CH), 1630, 1610, 1580, 1560, 1500, 1470,
1440 (C=N, C=C), 1330, 1240 (C–N), 720 (C–S)
3080 (CH), 1630, 1590, 1510, 1470, 1440 (C=N, C=C),
1320, 1240 (C–N), 720 (C–S)
4.58 (s, 2H, –S–CH2); 7.14–7.63 (m, 15H, Ar–H); 8.63 (s, 1, –CH=N–)
4.05 (s, 2H, –S–CH2); 6.62–7.51 (m, 16H, Ar–H); 7.97 (s, 1H, –CH=N–)
3012, 2811 (CH), 1626, 1581, 1513, 1468, 1440 (C=N,
C=C), 1288, 1243 (C–N)
2.38 (s, 3H, –CH3); 4.55 (s, 2H, –S–CH2); 7.21–7.94 (m, 15H, Ar–H), 8.62 (s, 1H,
–CH=N)
3447 (Ar–OH), 3067 (CH), 1626, 1588, 1514, 1487,
1438 (C=N, C=C), 1322,1277 (C–N), 723 (C–S)
3062 (CH), 1624, 1591, 1513, 1471, 1446 (C=N, C=C),
1309, 1267 (C–N), 721 (C–S)
2.37 (s, 3H, –CH3); 4.44(s, 2H, –S–CH2); 6.87–7.76 (m, 15H, Ar–H), 8.42 (s, 1H,
–H=N); 10.13 (s, 1H, Ar–OH)
2.38 (s, 3H, –CH3); 4.41(s, 2H, –S–CH2); 7.20–7.93 (m, 12H, Ar–H), 8.62 (s, 1H,
–CH=N)
3448 (Ar-OH), 3031 (CH), 1624, 1588, 1567, 1513,
1488 (C=N, C=C), 1304, 1247 (C–N), 721 (C–S)
2.37 (s, 3H, –CH3); 4.41(s, 2H, –S–CH2); 6.88–7.75 (m, 17H, Ar–H), 8.43 (s, 1H,
–CH=N); 10.13 (s, 1H, Ar–OH)
Some selected compounds, that showed activity in the
explained in terms of interaction at the binding site by the
pharmacophoric models, which were previously proposed
[24–26] (Scheme 2). In these models, it has been reported
that the existence of a hydrophobic unit (Ar), an electron
donor group (D) and hydrogen bonding domain (HBD) was
essential for anticonvulsant activity as evidenced by the ac-
tive drugs, such as carbamazepine, lamotrigine, phenytoin or
remacemide, fulfilling these demands. As shown in Scheme
2, the replacement of the amino group responsible for hydro-
gen bonding in compounds 11–20 also resulted in the lack of
a HBD leading to abolishment of activity seen with com-
pounds 21–31. This result is in accordance with the finding
that isatin-3-semicarbazones had some anticonvulsant pro-
perties whereas the corresponding isatin-3-hydrazones were
devoid of activity due to inability of hydrogen bonding at the
binding site (Scheme 2) [26].
In conclusion, these results indicate that either alkyl subs-
titution at triazole ring or protection of primary aromatic
amino group were essential for bioactivity together for com-
pounds 11–31. From the present study, two compounds (12
and 13) have emerged as the lead compounds with activity in
MES and scMET tests at 0.5 and 4 h. Further structural
modifications of these molecules might lead to the discovery
of more potent anticonvulsant agents with lower neurotoxi-
city.
MES test, were also subjected to oral MES screen in rats at a
dose of 30 mg/kg, and these data are summarized in Table 5.
Compounds 12, 13 and 14 tested in this model were found to
provide 50% protection at 1, 0.25 and 2 h, respectively. No
toxicity was seen at an oral dose of 30 mg/kg in oral MES
testing.
Compounds 11, 15, 24 and 28 were also screened using
6 Hz test, which depicts seizures in animals that are indica-
tive of the aura experienced in human patients with partial
seizures. Of these derivatives, only 11 exhibited some mode-
rate protection at the 0.5 h time point. The others in the series
were not active in this model.
Taken together, it was observed that small alkyl moieties
at N-4 of triazole ring maintained anticonvulsant activity;
whereas aryl substitution at the same position completely
blocked activity using both MES and scPTZ screens. This
was considered because aryl functions at triazole prevent the
triazole ring to reach binding sites due to steric influences.
Therefore alkyl substitution at the triazole ring appeared to
be preferable to aryl functions.
Another structural requirement for maintaining anticon-
vulsant activity was the presence of –NH2 function at the
fourth position of the phenyl ring as seen with compounds
11–20. This requirement was further evidenced by com-
pounds 21–31 where the –NH2 function was replaced with an
arylideneamino (–N=CH–Ar) moiety. The complete loss of
activity due to the disappearance of this function could be
In view of the antibacterial activity ascertained for similar
triazoles, the synthesized compounds were screened for anti-
bacterial and antimycobacterial activity [27,28] and found

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898
Table 4
Anticonvulsant and neurotoxicity screening of synthesized compounds 11–31
Compound
Intraperitoneal injection in mice a
scPTZ screen
4 h
MES screen
NT screen
0.5 h
−
4 h
−
0.5 h
−
% Mortality b
0.5 h
300
300
100
100
−
4 h
300
300
100
300
−
11
12
13
14
300
−
20
100
100
100
−
300
100
−
300
100
−
40
100
−
40
20
15
−
−
−
10
16
17
18
−
−
−
−
100
10
−
−
−
300
−
−
−
−
−
−
−
−
0
−
−
19
−
−
−
−
60
−
−
20
21
−
300
−
−
−
70
−
−
−
−
−
0
−
−
22
−
−
−
−
20
−
−
23
−
−
−
−
0
−
−
24
−
−
−
−
0
−
−
25
−
−
−
−
90
−
−
26
−
−
−
−
80
−
−
27
28
−
−
−
−
100
90
−
−
−
−
−
−
−
−
29
30
31
−
−
−
−
90
−
300
−
−
−
−
−
100
70
−
−
−
−
−
−
−
Phenytoinc
Carbamazepinec 30
Na. Valproatec
Phenobarbitald
Ethosuximided
30
30
100
−
−
−
NOT
NOT
NOT
NOT
NOT
100
100
−
100
300
−
100
300
30
300
300
−
300
100
30
−
30
−
100
−
300
−
−
a Doses of 30, 100 and 300 mg/kg were administered and the protection and neurotoxicity were measured after 0.5 and 4 h. The figures in the table indicate
the minimum dose at which protection or neurotoxicity was demonstrated in 50% or more of the mice. The dash (–) indicates an absence of activity/neurotoxicity
at maximum dose administered (300 mg/kg). NOT denotes not tested.
b All screening tests except PTZ-induced mortality were performed using Male albino mice according to the anticonvulsant drug development (ADD) program
protocol. The figures in this column represents PTZ-induced percent deaths which were determined in balb/c mice after administration of the test compounds,
as described in Section 4.3.1.
c Data from Refs. [21,22].
d Data from Ref. [23].
Table 5
Evaluation of selected compounds in the MES test after oral administration to rats
Compound
12
13
14
0.25 h
0.5 h
1 h
2
2 h
1
4 h
1
Toxicity
−
2
−
1
1
−
−
4
−
−
−
−
1
1
1
1
2
1
Phenytoin
3
3
3
The dose administered was 30 mg/kg. Four rats were used for each compound and the figures in the table indicate the number of rats protected. The dash (−)
means that no activity or toxicity was demonstrated.
inactive against the tested strains. Compounds 11–31 were
also tested for in vitro antituberculosis activity against M.
tuberculosis H37. Of these compounds, 15, 18, 20, 25, 26
and 29, which possess an aryl moiety at the N-4 position of
the triazole ring, displayed 50–59% inhibition at 6.25 µg/ml,
whereas alkyl substitution at the same position led to less
active derivatives. As none of the tested compounds exhibi-
ted >90% inhibition, they were not considered for further
screening.
4. Experimental protocols
4.1. Chemistry
Benzyl chloride, 2,4-dichlorobenzyl chloride and 2,6-
dichlorobenzaldehyde were purchased from Sigma. Methyl
and 4-methylphenyl isothiocyanates were supplied from
Fluka. All other chemicals and solvents were obtained from
Merck.

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899
Scheme 2. Structures of the synthesized compounds 11–31 and selected anticonvulsants from different classes showing the general pharmacophore model for
anticonvulsant activity [24–26]. The essential structural requirements are indicated by dotted rectangles (Ar: hydrophobic unit, D: electron donor group, HBD:
hydrogen bonding domain).
All melting points were recorded on a Büchi-530 melting
point apparatus and uncorrected. IR spectra were run on a
Perkin Elmer 1600 FT-IR spectrophotometer (1 mg/200 mg
as KBr pellets). 1H-NMR spectra were recorded on a Bruker
AVANC-DPX 400 spectrometer. Mass spectra were obtained
on a VG Zabspec GC-MS instrument at 70 eV in electron
impact mode. Combustion analyses were performed on a
Carlo Erba 1106 instrument.
4.1.2.1. 5-(4-Aminophenyl)-4-(4-methylphenyl)-2,4-dihy-
dro-3H-1,2,4-triazole-3-thione 10. C15H14N4S. Yield 80%.
M.p. 248–51 °C. IR (KBr) (m, cm–1): 3435, 3334 (NH2), 3205
(N–H), 2980 (C–H), 1625 (C=N), 1608, 1577, 1481, 1440
(C=C, C–N, N–H), 1327 (C–H), 1187 (C=S), 828, 816 (4-
1
substituted benzene). H-NMR (DMSO-d6) (d, ppm): 2.37
(s, 3H, –CH3), 6.43 (d, 2H, o–NH2, J=8.0 Hz), 6.94 (d, 2H,
m–NH2, J = 8.0 Hz), 7.16 (d, 2H, o–CH3, J = 8,0 Hz), 7.30 (d,
2H, m–CH3, J = 8.0 Hz), 13.78 (s, 1H, triazoline N–H).
Analysis (% C,H,N,S) (Calculated/found): C 63.81/64.05; H
4.99/5.24; N 19.84/19.61.
4.1.1. General procedure for compounds 1–5
Compounds 1–5 were prepared by the addition of
4-(benzoylamino)benzoic acid hydrazide [13] to various iso-
thiocyanates as described earlier [12]. Of these compounds, 1
(R1: CH3), 2 (R1: CH2CH=CH2), 3 (R1: C6H11) and 4 (R1:
C6H5) have been reported elsewhere [12] whereas compound
5 was synthesized as a novel compound in the present study.
4.1.3. General procedure for compounds 11–20
Compounds 6–10 (0.01 mol) was dissolved in ethanolic
sodium hydroxide (0.02 mol, 2N) and to this solution, equi-
molar amount of substituted benzyl chloride was added and
the whole mixture was gently refluxed for 5 h. At the end of
this duration, the flask content was allowed to cool and
poured into ice-cold water. The resulting precipitate was
filtered-off, washed with water and recrystallized from
ethanol-water.
4.1.1.1. 1-[4-(Benzoylamino)benzoyl]-4-(4-methylphenyl)-
thiosemicarbazide 5. C22H20N4O2S. Yield 80%. M.p. 177–
8 °C. IR (KBr) (m, cm–1): 3314 (N–H), 1667 (C=O, thiosemi-
carbazide), 1636 (C=O, amide), 1600, 1515, 1405 (C=C,
C–N, N–H), 1320 (C–H), 1185 (C=S), 846, 815 (4-
substituted benzene), 762, 703 (monosubstituted benzene).
1H-NMR (DMSO-d6) (d, ppm): 2.30 (s, 3H, –CH3), 7.15–
8.00 (m, 13H, Ar-H), 9.60 (s, 1H, –CONHNH–), 9.75 (s, 1H,
–CSNH–C6H4–), 10.41 (s, 1H, –CONH–C6H4), 10.47 (s,
4.1.4. General procedure for compounds 21–31
Compounds 11–20 (0.01 mol) were dissolved in metha-
nol. To this solution was added appropriate aldehyde
(0.01 mol). This mixture was refluxed in methanol contai-
ning two drops of glacial acetic acid for 1 h. The precipitated
crude product was then filtered-off, dried and recrystallized
from boiling methanol.
1H,
–CONHNH–).
Analysis
65.33/64.53;
(%
H
C,H,N,S)
4.98/5.22;
(Calculated/found):
C
N
13.85/13.37.
4.2. Microbiology
4.1.2. General procedure for compounds 6–10
Compounds 6–10 were prepared by refluxing 1–5 in so-
dium hydroxide solution (2N) followed by treatment of so-
dium salts with HCl to give the desired compounds. Of these
compounds, 6 (R1: CH3), 7 (R1: CH2CH=CH2), 8 (R1:
C6H11) and 9 (R1: C6H5) have been reported elsewhere [10]
whereas compound 10 was synthesized as a novel compound
in the present study.
4.2.1. Antimicrobial activity
The synthesized compounds 11–31 were evaluated in
vitro for their antibacterial and antifungal activities against
Staphylococcus aureus ATCC 6538, Staphylococcus epider-
midis ATCC 12228, as Gram-positive; Klebsiella pneumo-
niae ATCC 4352, Pseudomonas aeruginosa ATCC 1539,

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900
Eschericha coli ATCC 8739, Salmonella typhi, Shigella
flexneri and Proteus mirabilis as Gram-negative bacteria
besides a yeast-like fungus, C. albicans ATCC 10231. Preli-
minary antimicrobial investigations were carried out utili-
zing the disc diffusion [27] and microdilution methods [28]
as described in the literature.
rating rotorod that rotates at 10 rpm. The rod diameter was
3.2 cm. Trained animals were injected intraperitoneally with
the test compounds at doses of 30, 100 and 300 mg/kg.
Neurotoxicity was indicated by the inability of the animal to
maintain equilibration on the rod for at least 1 min in each of
the three trails. The results are shown in Tables 4 and 5.
4.2.2. In vitro evaluation of antimycobacterial activity
against M. tuberculosis H37Rv
Acknowledgements
Primary screen was conducted at 6.25 µg/ml against
M. tuberculosis H37Rv in BACTEC 12B medium using the
BACTEC 460 radiometric system [29]. Rifampicin was used
as the standard in the antimycobacterial assays. Compounds
effecting <90% inhibition in the primary screen
(MIC > 6.25 µg/ml) were not evaluated further.
This work was supported by Research Fund of Marmara
University (Project number: 1996 SB DYD-17). We thank
Dr. J.A. Maddry from the Tuberculosis Antimicrobial Acqui-
sition and Coordinating Facility (TAACF), National Institute
of Allergy and Infections Diseases Southern Research Insti-
tute, GWL Hansen’s Disease Centre, Colorado State Univer-
sity, Birmingham, AL, USA, for the in vitro evaluation of
antimycobacterial activity using M. tuberculosis H37Rv. We
would also like to thank Drs. H. Wolf, S. White and K.
Wilcox of the University of Utah for their aid in generating
anticonvulsant data.
4.3. Pharmacology
4.3.1. Pentylenetetrazole mortality on mice
Anticonvulsant activity was determined against penty-
lenetetrazole-induced seizures [30,31] in male Balb/c mice
weighing 20–30 g. The mice were divided into groups of ten
keeping the group weights as equal as possible. All the
synthesized compounds 11–31 were suspended in 5%
aqueous gum acacia to give a concentration of 1% (w/v). The
test compounds were injected i.p. into a group of ten mice.
Control animals were injected with vehicle only. Four hours
after the administration of either vehicle or test compounds,
the animals were injected with pentylenetetrazole (90 mg/kg,
s.c.). This dose of pentylenetetrazole was shown to produce
convulsions in all untreated mice and these animals exhibited
100% mortality during 24 h. The mice that survived after 24 h
were considered to be protected. The number of protected
animals in each group was recorded and the anticonvulsant
activity of compounds 11–31 were represented as the percent
protection.
References
[1] G.A.R. Johnston, Medicinal Chemistry and Molecular Pharmacology
of GABAC Receptors, Current Topics in Medicinal Chemistry 2
(2002) 903–913.
[2] J.H. Kehne, J.M. Kane, S.F. Chaney, G. Hurst, T.C. McCloskey,
M.A. Petty, Y. Senyah, H.H. Wolf, R. Zobrist, H.S. White, Preclinical
characterization of MDL 27,192 as a potential broad spectrum anti-
convulsant agent with neuroprotective properties, Epilepsy Res. 27
(1997) 41–54.
[3] J.M. Kane, B.M. Baron, M.W. Dudley, S.M. Sorensen, M.A. Staeger,
F.P. Miller, 2,4-Dihydro-3H-1,2,4-triazol-3-ones as anticonvulsant
agents, J. Med. Chem. 33 (1990) 2772–2777.
4.3.2. Anticonvulsant Screening Program at the National
Institue of Neurological Disorders and Stroke (NINDS,
NIH)
[4] D. Ashton, J. Fransen, J. Heeres, G.H. Clincke, P.A. Janssen, In vivo
studies on the mechanism of action of the broad spectrum anticonvul-
sant loreclezole, Epilepsy Res. 11 (1992) 27–36.
The anticonvulsant evaluation were undertaken by the
National Institue of Neurological Disorders and Stroke
(NINDS, NIH). Male albino mice (CF#1 strain, 18–25 g) and
male albino rats (Sprague–Dawley, 100–150 g) were used as
experimental animals. The compounds were suspended in
0.5% methylcellulose/water mixture. All the compounds
were administrated i.p. in a volume of 0.01 ml/g body weight
for mice and 0.004 ml/g body weight for rats at doses of 30,
100 and 300 mg/kg to one to four animals. Activity was
established using the MES, scPTZ and neurotoxicity. Some
selected compounds described in this study were examined
for oral activity in the MES screen and for 6 Hz screen which
uses a threshold stimulus vs. the maximal electroshock su-
prathreshold stimulation [20]. The results are presented in
Tables 4 and 5.
[5] P.K. Kadaba, P.J. Stevensen, I.P. Nnane, L.A. Damani, Triazolines-
XXVII. delta2-1,2,3-triazoline anticonvulsants: novel ‘built-in’ het-
erocyclic prodrugs with a unique ‘dual action’mechanism for impair-
ing excitatory amino acid L-glutamate neurotransmission, Bioorg.
Med. Chem. 4 (1996) 165–178.
[6] A. Chimirri, R. Gitto, S. Quartarone,V. Orlando,A. De Sarro, G.B. De
Sarro, Synthesis and pharmacological propeties of new
3-ethoxycarbonyl-11H-[1,2,4]triazolo[4,5-c][2,3]benzodiazepines,
Farmaco 57 (2002) 759–763.
[7] E. Southam, S.C. Stratton, R.S. Sargent, K.T. Brackenborough,
C. Duffy, R.M. Hagan, G.D. Pratt, S.A. Jones, P.F. Morgan, Broad
spectrum anticonvulsant activity of BW534U87: possible role of an
adenosine-dependent mechanism, Pharmacol. Biochem. Behav. 74
(2002) 111–118.
[8] T. Akbarzadeh, S.A. Tabatabai, M.J. Khoshnoud, B. Shafaghi,
A. Shafiee, Design and Synthesis of 4H-3-(2-Penoxy)phenyl-1,2,4-
triazole Derivatives as Benzodiazepine Receptor Agonists, Bioorg.
Med. Chem. 11 (2003) 769–773.
4.3.3. Neurotoxicity (NT) screening
The minimal motor impairment was measured in mice by
the rotorod test. The mice were trained to stay on an accele-
[9] P.K. Kadaba, Rational drug design and the discovery of the delta2-
1,2,3-triazolines, a unique class of anticonvulsant and antiischemic
agents, Curr. Med. Chem. 10 (2003) 2081–2108.

˙
I. Küçükgüzel et al. / IL FARMACO 59 (2004) 893–901
901
[10] S. Rollas, N. Kalyoncuoglu, D. Sur-Altiner, Y. Yegenoglu, 5-(4-
Aminophenyl)-4-substituted-2,4-dihydro-3H-1,2,4-triazole-3-
thiones: Synthesis and antibacterial and antifungal activities, Pharma-
zie 48 (1993) 308–309.
[11] I. Küçükgüzel, S.G. Küçükgüzel, S. Rollas, M. Kiraz, Some
3-thioxo/alkylthio-1,2,4-triazoles with a substituted thiourea moiety
as possible antimycobacterials, Bioorg. Med. Chem. Lett. 11 (2001)
1703–1707.
[12] N. Kalyoncuoglu, S. Rollas, D. Sür-Altiner, Y. Yegenoglu, 1-[p-
(Benzoylamino)benzoyl]-4-substituted thiosemicarbazides: Synthe-
sis and antibacterial and antifungal activities, Pharmazie 47 (1992)
796–797.
[21] J.R. Dimmock, R.N. Puthucode, J.M. Smith, M. Hetherington,
J.W. Quail, U. Pugazhenthi, T. Lechler, J.P. Stables, (Aryloxy)aryl
semicarbazones and related compounds: a novel class of anticonvul-
sant agents possessing high activity in the maximal electroshock
screen, J. Med. Chem. 39 (1996) 3984–3997.
[22] R.J. Porter, J.J. Cereghino, G.D. Gladding, B.J. Hessie, H.J. Kupfer-
berg, B. Scoville, B.G. White, Antiepileptic drug development pro-
gram, Cleveland Clin. Quart. 51 (1984) 293–305.
[23] P.T. Flaherty, T.D. Greenwood, A.L. Manheim, J.F. Wolfe, Synthesis
and evaluation of N-(phenylacetyl)trifluoromethanesulfonamides as
anticonvulsant agents, J. Med. Chem. 39 (1996) 1509–1513.
[24] K. Unverferth, J. Engel, N. Höfgen, A. Rostock, R. Günther,
H.J. Lankau, M. Menzer, A. Rolfs, J. Liebscher, B. Müller, H.J. Hof-
mann, Synthesis, anticonvulsant activity, and structure–activity rela-
tionships of sodium channel blocking 3-aminopyrroles, J. Med.
Chem. 41 (1998) 63–73.
[13] B.B. Durgun, S. Rollas, Synthesis and characterization of some aryl-
hydrazones of p-(benzoylamino)benzoic acid hydrazide, J. Pharm.
Univ. Mar. 7 (1991) 107–111.
[14] B.S. Holla, M.K. Shivananda, S. Shenoy, G. Antony, Studies on
arylfuran derivatives—Part VIII. Synthesis, characterization and anti-
bacterial activities of some 1-aminomethyl-3-substituted-4-[5-(4-
nitrophenyl-2-furfurylidene)] amino-1,2,4-triazole-5-thiones, Boll.
Chim. Farmaceutico 137 (1998) 233–238.
[25] S.N. Pandeya, P. Yogeeswari, J.P. Stables, Synthesis and anticonvul-
sant activity of 4-bromophenyl substituted aryl semicarbazones, Eur.
J. Med. Chem. 35 (2000) 879–886.
[15] S. Rollas, Reductive cleavage of azo compounds with hydrazine
hydrate and some new 1,2,4-triazole derivatives II, M.U. J. Sci. Tech-
nol. 3 (1986) 195–200 [ref.: CA 107, 58943d (1987)].
[26] S.N. Pandeya, A.S. Raja, J.P. Stables, Synthesis of isatin semicarba-
zones as novel anticonvulsants—role of hydrogen bonding, J. Pharm.
Pharmaceut. Sci. 5 (2002) 266–271.
[16] S.G. Küçükgüzel, S. Rollas, H. Erdeniz, M. Kiraz, Synthesis, charac-
terization and antimicrobial evaluation of ethyl 2-arylhydrazono-3-
oxobutyrates, Eur. J. Med. Chem. 34 (1999) 153–160.
[17] I. Küçükgüzel, S. Rollas, M. Ülgen, Synthesis and characteriaztions
of some thiourea derivatives from 1,2,4-triazoline-3-thiones, J.
Pharm. Univ. Mar. 10 (1994) 17–25.
[18] S.G. Kömürcü, S. Rollas, M. Ülgen, J.W. Gorrod,A. Çevikbas, Evalu-
ation of some arylhydrazones of p-aminobenzoic acid hydrazide as
antimicrobial agents and their in vitro hepatic microsomal metabo-
lism, Boll. Chim. Farmaceutico 134 (1995) 375–379.
[19] S.G. Küçükgüzel, S. Rollas, I. Küçükgüzel, M. Kiraz, Synthesis and
antimycobacterial activity of some coupling products from
4-aminobenzoic acid hydrazones, Eur. J. Med. Chem. 34 (1999)
1093–1100.
[27] A.L. Barry, C. Thornsberry, Susceptibility tests: Diffusion test proce-
dures, in: E.H. Lennette, A. Balows, W.J. Hausler, H.J. Shadomy
(Eds.), Manual of Clinical Microbiology, ASM, Washington DC,
1986, pp. 978–987.
[28] R.N. Jones,A.L. Barry, T.L. Gavan, J.A. Washington II, Susceptibility
tests: Microdilution and Macrodilution broth procedures, in:
E.H. Lennette,A. Balows, W.J. Hausler, H.J. Shadomy (Eds.), Manual
of Clinical Microbiology, ASM, Washington DC, 1986, pp. 972–977.
[29] L. Collins, S.G. Franzblau, Microplate alamar blue assay versus
BACTEC 460 system for high-throughput screening of compounds
against Mycobacterium tuberculosis and Mycobacterium avium,
Antimicrob. Agents Chemother. 41 (1997) 1004–1009.
[30] S.P. Singh, B.R. Pandey, S. Kumar, S.S. Parmar, Anticonvulsant activ-
ity and inhibition of respiration in rat brain homogenates by substi-
tuted trimethoxybenzamides, J. Pharm. Sci. 67 (1978) 1682–1684.
[20] J. Stables, H.J. Kupferberg, The NIH anticonvulsant drug develop-
ment (ADD) program: preclinical anticonvulsant screening project,
in: G. Avanzini, G. Regesta, P. Tanganelli, M. Avoli (Eds.), Molecular
and Cellular Targets for Anti-epileptic Drugs, 1997, pp. 191–198,
(Chapter 16).
[31] V.K. Srivastava, B.R. Pandey, R.C. Gupta, K. Kishor, New CNS-
active 3-methyl-4-substituted methyl-delta 2-isoxazolin-5-ones,
Pharmazie 34 (1979) 638–639.