Preparation and antimicrobial activity evaluation of some new bi- and triheterocyclic azoles

MEDICINAL

CHEMISTRY

RESEARCH

Med Chem Res (2013) 22:4930–4945

DOI 10.1007/s00044-013-0498-3

ORIGINAL RESEARCH

Preparation and antimicrobial activity evaluation

of some new bi- and triheterocyclic azoles

•

Serpil Demirci Serap Basoglu Arif Bozdereci

Neslihan Demirbas

Received: 14 November 2012 / Accepted: 16 January 2013 / Published online: 3 February 2013

Ó Springer Science+Business Media New York 2013

Abstract Synthesis of the carbothioamides (5, 13, 22)

was performed starting from 3H-1,2,4-triazol-3-ones (2,

17) by several steps, and then, these carbothioamides was

converted to triheterocyclic compounds incorporating

1,2,4-triazole, imidazole and 1,3-thiazol(idinone) moieties.

The reaction of compound 2 with 3,4-diﬂuoronitrobenzene

afforded the 2-(2-ﬂuoro-4-nitrophenyl) derivative, 10.

Compound 10 was converted to the arylideneamino

derivatives (12a, b) via the reduction of nitro group. On the

other hand, the treatment of the hydrazide (20) that was

obtained starting from 17, with several aromatic aldehydes

generated the corresponding arylidenhydrazides (21a–c).

Mannich reaction between compound 2 and a suitable

heterocyclic amine resulted in the N-alkylation of 2. All

newly synthesized compounds were screened for their

antimicrobial activities. In general, most compounds

except 22 were Found (%) to be active against Mycobac-

terium smegmatis, Candida albicans and/or Saccharomy-

ces cerevisiae. Furthermore, 9a and b, which are Mannich

bases incorporating morpholine or piperazine nucleus,

exhibited excellent antimicrobial activity on test microor-

ganisms. In addition, the hydrazide, 4, was Found (%) to

have activity towards Ec and Yp.

Introduction

The limitations in the use of the existing antibacterial drugs

due to various reasons such as drug resistance, the serious

side effects and/or lack of efﬁcacy made infectious diseases

a vicious cycle. In addition, the treatment of resistant strains

requires a prolonged therapy containing the use of more

toxic drugs and increases the ﬁnancial burden. One of the

infections leading to death is tuberculosis (TB). According

to the survey reported by Global Alliances, there are 8–10

million new active cases of TB with approximately 3 mil-

lion deaths each year (Mallikarjuna et al., 2009; Kumar

et al., 2010; Silverman, 2004; Pablos-Mendez et al., 1998).

Therefore, it is inevitable to discover and develop new

drugs for the treatment of dreadful infections, which have

spread worldwide now. To search and synthesize of com-

binational chemotherapeutic drugs with different mecha-

nisms of action and low side effects constitutes an

important part of the methods aiming to overcome the

antimicrobial resistance. Beside the exploitation of new

targets, there is another approach that contains to combine

two different groups responsible for biological activity in

one molecule. According to the literature data, more efﬁ-

cacious antibacterial compounds can be designed by join-

ing two or more biologically active heterocyclic nuclei in a

single molecular framework (Thomas et al., 2011; Kumar

et al., 2010; Solomon et al., 2010; Hu et al., 2010; Patil

et al., 2010; Bayrak et al., 2010). These two pharmaco-

phores, by addressing the active site of two different tar-

gets, offer the possibility to overcome the current resistance

and in addition to reduce the appearance of new resistant

strains (Chandra et al., 2006; Yu and Huiyuan, 2002;

Phillips et al., 2007; Bonde and Gaikwad, 2004; Dixit

et al., 2006; Hubschwerlen et al., 2003). Nevertheless, the

majority of the efforts on the discovery new antibacterial

Keywords 1,2,4-Triazole ꢀ 1,3-Thiazole ꢀ

1,3-Thiazolidinone ꢀ Arylidenhydrazide ꢀ Mannich base ꢀ

Antimicrobial activity

S. Demirci ꢀ S. Basoglu ꢀ N. Demirbas (&)

Department of Chemistry, Faculty of Art and Sciences,

Karadeniz Technical University, 61080 Trabzon, Turkey

e-mail: neslihan@ktu.edu.tr

A. Bozdereci

Department of Biology, Recep Tayyip Erdogan University,

53100 Rize, Turkey

˘

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Med Chem Res (2013) 22:4930–4945

4931

agents are based on analogue-based approach and that their

market value represents two-thirds of all drug sales (Vicini

et al., 2008; Basoglu et al., 2012).

considerable importance for the synthesis and modiﬁcation

of biologically active compounds (Demirbas et al., 2010).

Several Mannich bases have been Found (%) to possess

antibacterial, antifungal, anticancer, antitubercular, analge-

sic and anti-inﬂammatory properties (Almajan et al., 2009).

Certain small heterocyclic molecules act as highly

functional scaffolds and they are known as important

molecule parts of a number of biologically active and

medicinally useful molecules (Nandhakumar et al., 2007).

Motivated by these ﬁndings and in continuation of our

ongoing efforts endowed with the discovery of nitrogen-

ated heterocycles with potential chemotherapeutic activi-

ties, we would like to report here the synthesis and

investigation of antimicrobial activities of new 1,2,4-tria-

zole derivatives incorporating various heterocyclic rings

responsible for biological activity in a single structure such

as 1,2,4-triazole, 1,3-thiazole 1,3-thiazolidinone, morpho-

line piperazine or 1,3-thiazole moieties.

Triazoles have been shown to possess a number of

desirable features in the context of medicinal chemistry

such as stability to acidic and basic hydrolysis, reductive/

oxidative conditions and also resistance to metabolic deg-

radation. Their varied biological activities such as anti-

bacterial (Genin et al., 2000), antifungal (Xu et al., 2011),

antiallergic (Buckle et al., 1986), anti-HIV (Alvarez et al.,

1994), anticonvulsant (Deng et al., 2011), anti-inﬂamma-

tory (Abdel-Megeed et al., 2009) and b-lactamase inhibi-

tion properties (Faridoon et al., 2012) made 1,2,4-triazole

derivatives important tools in the medicinal chemistry.

Tazobactam, a b-lactamase inhibitor is the best known

examples of triazole containing structures with the broad-

spectrum antibiotic piperacillin (Whiting et al., 2006;

Tornoe et al., 2004). Favourable properties and enhanced

biological activities of triazole nucleus have been attributed

to its dipole character, hydrogen bonding capability,

rigidity and stability under in vivo conditions (Kategaonkar

et al., 2010; Eswaran et al., 2009).

Results and discussion

Thiazolidinone derivatives have been further reported to

possess diverse pharmacological properties, such as antibac-

terial, antifungal, anticonvulsant, anticancer, anti-TB and anti-

human immunodeﬁciency virus type 1 (HIV-1) activities.

Thiazolidinones are novel inhibitors of the bacterial enzyme

MurB, a precursor acting during the biosynthesis of peptido-

glycan as an essential component of the cell wall of both gram-

positive and -negative bacteria (El-Gaby et al., 2009; Ku-

cukguzeletal., 2002; Aridoss et al., 2007;Basogluetal., 2012).

Substituted piperazines are important molecule portions

of a number of important drugs such as crixivan, an HIV

protease inhibitor, piperazinyl-linked ciproﬂoxacin dimers,

which are potent antibacterial agents and an oxazolidinone

antibiotic eperezolid (Yolal et al., 2012). The drugs pra-

zosin, lidoﬂazine and urapidil, which contain a piperazine

nucleus in their structures, have been used as cardiovas-

cular agents (Karthikeyan et al., 2006; Ridley et al., 2004).

Another important group responsible for biological

activity, morpholine is incorporated in a wide variety of

therapeutically important drugs, one of which is linezolid

that belongs to the oxazolidinone class of antibiotics and

used for the treatment of infections caused by gram-posi-

tive bacteria (Sahin et al., 2012; Wyrzykiewicz et al., 2006;

Dixit et al., 2005; Panneerselvam et al., 2005). Further-

more, 4-phenylmorpholine derivatives have been reported

to possess antimicrobial, anti-inﬂammatory and central

nervous system activities (Dixit et al., 2006).

The synthetic route for the newly synthesized compounds

is illustrated and outlined in Schemes 1, 2, 3, 4, 5 and 6.

The synthesis of compound 2 was performed from the

reaction of compound 1 with 3-(1H-imidazol-1-yl)-prop-

anamine. Then, compound 2 was converted to hydrazide

(4) via the formation of the corresponding ester (3). Other

ester, compound 20, was obtained starting from compound

17 via the formation of its Schiff base derivative, 19. The

1

IR and H NMR spectra of compounds 4 and 20 displayed

signals pointing the presence of hydrazide function,

whereas the signals due to ester group disappeared in the

NMR spectra of these compounds. The treatment of

hydrazides (4 and 20) with phenylisothiocyanate produced

1

the corresponding carbothioamides (5 and 22). In the H

NMR spectra of these carbothioamides, the signal derived

from NH₂group disappeared, instead, additional signals

originated from phenyl moiety and three NH function were

recorded at the related chemical Schiff values. Moreover,

compounds 5 and 22 exhibited EI MS spectra and ele-

mental analysis data consistent with the proposed structure.

The synthesis of 1,3-thiazole derivatives (6 and 24) was

carried out by the cyclocondensation reaction between

4-chlorophenacyl bromide and the corresponding carbo-

thioamide (5 or 22). On the other hand, the treatment of

compound 5 with ethyl bromoacetate resulted in the for-

mation of 1,3-thiazolidin-2-ylidene]acetohydrazide deriv-

ative (7). The structures of these compounds were

1

The Mannich reaction is a three-component condensation

reaction involving an active hydrogen containing compound,

formaldehyde and a secondary amine. The aminomethyla-

tion of aromatic substrates by the Mannich reaction has a

conﬁrmed on the basis of FT-IR, EI MS, H-, ¹³C NMR

spectroscopic methods and elemental analysis.

The aminoalkylation of compound 2 with several

amines namely morpholine, piperidine, phenylpiperazine,

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Med Chem Res (2013) 22:4930–4945

Scheme 1 Synthetic pathway

for the preparation of compounds

2–5. i 3-(1H-imidazol-1-yl)

propanamine, ii ethyl

bromoacetate, iii hydrazine

hydrate, iv phenylisothiocyanate

O

N NH

N

O

OEt

N

i

ii

NNH

OEt

CH₃

O

CH₃

OEt

O

N

CH₃

1

N

3

2

iii

O

S

NH

NHNH₂

N

NHNH

N

iv

CH₃

O

N

CH₃

O

N

4

N

5

furan-2-ylmethanamine, 2-(piperazin-1-yl)ethanamine and

6-aminopenicillanic acid in the presence of formaldehyde

afforded the corresponding Mannich bases, (9a–c). In

NMR spectra of compounds 9a–c, the presence of the

peaks belonging to amine moiety used in this reaction

conﬁrmed the condensation. Moreover, these compounds

exhibited elemental analysis data consistent with the pro-

posed structures.

presence of Pd–C catalyst. The IR spectra of 10 displayed

two sharp signals at1,334and 1,495 cm^-1due to nitro group,

while IR spectra of 11 exhibited NH₂absorption at 3,387 and

3,487 cm^-1. The latter group resonated at 4.88 ppm in the

¹H NMR spectrum of compound 11 as D₂O exchangeable

singlet. Moreover, additional signals originated from phenyl

moiety recorded at aromatic region in the ¹H- and ¹³C NMR

spectra of compounds 10 and 11.

The basic treatment of intermediates 5 and 22 afforded [(5-

mercapto-4-phenyl-4H-1,2,4-triazol-3-yl)methyl]-5-methyl-

2,4-dihydro-3H-1,2,4-triazol-3-one derivatives (8 and 23).

In the ¹H NMR spectra of compounds 8 and 23, the signal due

to SH group was recorded at 10.11 and 13.55 ppm, respec-

tively, as an evidence of intramolecular cyclisation. This

group was seen at 2,857 cm^-1in the FT-IR spectra. In the

¹³C NMR spectra of compounds 8 and 23, the C-3 and C-5

carbon atoms belonging to 1,2,4-triazole nucleus resonated

at the chemical Schiff values consistent with the literature

ﬁndings (Buckle et al., 1986; Vicini et al., 2008; Xu et al.,

2011]. Furthermore, [M]^?ion peaks were observed at the

related m/z value supporting the proposed structure, and

these compound gave reasonable elemental analysis data.

The treatment of compound 2 with 3,4-diﬂuoronitroben-

zene generated 4-[3-(1H-imidazol-1-yl)propyl]-5-methyl-2-

(4-nitrobenzyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (10). Then,

this compound (10) was converted to the corresponding

amine (11) by the treatment with hydrazine hydrate in the

The reaction of amine, 11 with aromatic aldehydes

namely 4-bromobenzaldehyde and 2,6-dichlorobenzalde-

hyde produced the corresponding arylmethylenamino

compounds 12a and b. On the other hand, the reaction of

hydrazide 20 with several aromatic aldehydes afforded the

corresponding arylidenhydrazides (21a–c). In the ¹H NMR

spectra of these compounds, the signal derived from NH₂

group disappeared, instead, new signals originated from

imine bond and aldehyde moiety were recorded at the

related chemical shift values. Moreover, these compounds

(12a, b and 21a–c) exhibited EI MS and elemental analysis

data supporting the proposed structures.

The synthesis of 2-{5-[(3-benzyl-4-oxo-1,3-thiazolidin-

2-ylidene)amino]-2-ﬂuorophenyl}-4-[3-(1H-imidazol-1-yl)

propyl]-5-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one (14)

was performed from the cyclocondensation reaction

between ethyl bromoacetate and compound 13 that was

obtained by the treatment of amine 11 with benzylisothio-

cyanate. On the other hand, the treatment of the same

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Med Chem Res (2013) 22:4930–4945

4933

Scheme 2 Reactions and

conditions leading to the

O

S

formation of compounds 6–9.

i 4-chlorophenacyl bromide, ii

ethyl bromoacetate, iii NaOH

NHNH

N

O

NH

N

CH₃

O

N

NHN

i

S

CH₃

O

N

Cl

N

5

N

6

iii

ii

O

N

S

SH

N

NHN

N

O

CH₃

O

N

CH₃

O

N

8

7

intermediate 11 with 4-chlorophenacyl bromide pro-

duced 2-(4-amino-2-ﬂuorophenyl)-5-methyl-2,4-dihydro-

3H-1,2,4-triazol-3-one (15). In this reaction, the expected

product 16 could not be obtained as a result of hydrolysis.

The structures of compounds 14 and 15 were conﬁrmed on

Moreover, these compounds exhibited good activity towards

Mycobacterium smegmatis (Ms), a non-pigmented, rapidly

growing mycobacterium and an atypical TB factor leading to

morbidity and mortality, beside Candida albicans (Ca) and

Saccharomyces cerevisiae (Sc) which are yeast like fungy.

Other compounds possessing activity on Ms displayed MIC

values between 0.24 and 250 lg/mL. except compounds 3,

10, 19, 21–24 which were Found (%) to be inactive against

Ms. Among the compounds having Ms activity, the activity

of 12a is better than standard drug streptomycin with the

MIC value 0.24 lg/mL while compounds 9b and 12a dis-

played as anti-Ms activity as the standard drug, streptomy-

cin. In general, all compounds, except 4, 7, 12b and 22,

demonstrated activity on yeast like fungy, Ca and/or Sc with

the MIC values varying 3.9–1,000 lg/mL. Among these

compounds, the ones having the most activity are com-

pounds 9a and b.

1

the basis of FT-IR, EI MS, H-, ¹³C NMR spectroscopic

methods and elemental analysis. An evidence for the for-

mation of 15 is the absence of any signals due to imidazol-1-

ylpropyl and two phenyl moieties in the ¹H- and ¹³C NMR

spectra, and the presence of D₂O exchangeable signals

observed at 5.52 and 8.26 ppm, which were attributed to NH₂

and NH functions, respectively. In the EI MS spectrum of

compound 15, the presence of [M ? H₂O]^?and [M]^?ion

peaks constitutes another evidence for the formation of

hydrolysis product, 15.

The newly synthesized compounds 2–24 were evaluated

in vitro for their antimicrobial activities and the results are

presented in the Table 1. Among the compounds tested,

compounds 9a–f which contain different heterocyclic moi-

eties with the Mannich base structure were Found (%) to be

most active against all the test microorganisms. Furthermore,

the activities of compounds 9a–c appear to be better than the

standard drug, ampicillin with the minimal inhibition con-

centration (MIC) values varying between 0.12 and 62.5 lg/mL.

Conclusion

This study reports the synthesis of some new 1,2,4-triazole

derivatives incorporating several other heterocyclic moie-

ties having importance for biological activity in a single

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Med Chem Res (2013) 22:4930–4945

Scheme 3 Synthetic pathway

for the preparation of

F

NO₂

NH₂

F

compounds 10–12. i 3,4-

diﬂuoronitrobenzene, ii HCHO

and amine, iii 2,6-

dichlorobenzaldehyde or

4-bromobenzaldehyde

N NH

N

CH₃

O

CH₃

O

N

iii

i

N

2

10

11

ii

iv

R

F

N

CHAr

N

CH₃

N

O

N

CH₃

O

N

9a-f

N

12a,b

N

O

9a: R=

N

9b: R=

9d: R=

Cl

12a: Ar=

12b: Ar=

N

NH

9c: R=

9e: R=

O

Br

NH

O

N

NH

9f: R=

NH

S

N

COOH

structure. Hence, herein, we combined all these potential

chemotherapeutic units, namely 1,2,4-triazole, imidazole,

pyridine, 1,3-thiazole, 1,3-thiazolidinone, piperazine,

morpholine, piperidine and penicillic acid moieties. The

antimicrobial screening studies were also performed in the

study. 1,2,4-Triazole nucleus is one of the active compo-

nents present in many standard drugs and it is known to

increase the pharmacological activity of the molecules.

Other heterocyclic groups getting involved in the structures

of the new synthesized compounds in the study are known

to have an important role for contributing to the net bio-

logical activity of a system. The structures of new com-

pounds were conﬁrmed by IR, ¹H-, ¹³C NMR, mass

spectroscopic and elemental analysis techniques. In addi-

tion, the newly synthesized compounds were screened for

their antimicrobial activities.

The antimicrobial screening suggests that among the

newly synthesized compounds, 9a–f exhibited excellent

activities against most of the test microorganisms. Other

new compounds were Found (%) to possess activity espe-

cially on Ca and Sc.

Experimental

Chemistry

General information for chemicals

All the chemicals were purchased from Fluka Chemie AG

Buchs (Switzerland) and used without further puriﬁcation.

Melting points of the synthesized compounds were

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Med Chem Res (2013) 22:4930–4945

4935

Scheme 4 Reaction and

conditions for the synthesis of

compounds 14–16. i

S

NH₂

F

NH

PhCH2NCS, ii ethyl

bromoacetate, iii

4-chlorophenacyl bromide

N

i

N

CH₃

O

N

CH₃

O

N

11

13

ii

iii

O

N

F

N

S

N

F

N

S

CH₃

NH₂

O

N

CH₃

O

Cl

N

F

N

CH₃

O

N

H

14

15

16

4-[3-(1H-imidazol-1-yl)propyl]-5-methyl-2,4-dihydro-3H-

1,2,4-triazol-3-one (2) A mixture of the corresponding

compound 1 (10 mmol) and imidazole (10 mmol) was

heated in an oil bath at 135 °C for 3 h. On cooling it to

room temperature, a solid was obtained. This crude product

was recrystallized from ethyl acetate to give the pure

compound. Yield: 1.69 g, 82 %, mp 161 °C. IR (KBr, t,

determined in open capillaries on a Bu¨chi B-540 melting

point apparatus and are uncorrected. Reactions were

monitored by thin-layer chromatography (TLC) on silica

gel 60 F254 aluminium sheets. The mobile phase was

ethanol:ethyl acetate, 1:1, and detection was made using

UV light. FT-IR spectra were recorded as potassium bro-

mide pellets using a Perkin Elmer 1600 series FT-IR

1

cm^-1): 3192 (NH), 3020 (ArCH), 1597 (C=O). H NMR

1

spectrometer. H- and ¹³C NMR spectra were registered in

(DMSO-d₆, d ppm): 1.96–2.10 (m, 5H, CH₃? CH₂), 3.49

(s, 2H, CH₂), 3.97 (t, 2H, CH₂, J = 6.0 Hz), 6.89 (s, 1H,

ArH), 7.23 (s, 1H, ArH), 7.68 (s, 1H, ArH), 11.46 (s, 1H,

NH, D₂O exch.). ¹³C NMR (DMSO-d₆, d ppm): 12.03

(CH₃), 30.83 (CH₂), 40.89 (CH₂), 44.13 (CH₂), ArC:

[120.00 (CH), 129.08 (2CH), 145.09 (C), 155.76 (C=O)].

EI MS m/z (%): 230.00 ([M ? Na]^?, 9), 209.04 (18),

207.98 ([M]^?, 95), 140.96 (40), 139.83 (100), 116.92 (15).

Elemental analysis for C₉H₁₃N₅O, Calculated (%), C:

52.16; H: 6.32; N: 33.79.

dimethylsulfoxide (DMSO)-d₆on a BRUKER AVENE II

400 MHz NMR Spectrometer (400.13 MHz for ¹H and

100.62 MHz for ¹³C). The chemical shifts are given in ppm

relative to Me₄Si as an internal reference, J values are

given in Hz. The elemental analysis was performed on a

Costech Elemental Combustion System CHNS–O elemen-

tal analyser. All the compounds gave C, H and N analysis

within 0.4 % of the theoretical values. The mass spectra

were obtained on a Quattro LC–MS (70 eV) Instrument.

Compounds 1, 2 and 17 were synthesized by the way

reported previously (Bektas et al., 2010a, b).

Found (%), C: 52.29; H: 6.29; N: 34.01.

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Med Chem Res (2013) 22:4930–4945

N

2H, CH₂, J_2,3= 6.4 Hz, J_1,3= 8.2 Hz), 3.97 (t, 2H, CH₂,

NH

i

J = 6.3 Hz), 4.11 (dd, 2H, CH₂, J_1,2= 6.6 Hz, J_1,3

=

CH₃

O

N

7.8 Hz), 4.49 (s, 2H, CH₂), 6.89 (s, 1H, ArH), 1.23 (s, 1H,

ArH), 7.66 (s, 1H, ArH). ¹³C NMR (DMSO-d₆, d ppm):

8.06 (CH₃), 10.94 (CH₃), 26.94 (CH₂), 37.53 (CH₂), 40.17

(CH₂), 42.99 (CH₂), 58.04 (CH₂), 116.20 (CH), 125.29

(2CH), 140.92 (triazole C-5), 150.65 (triazole C-3), 164.89

(C=O). EI MS m/z (%): 332.30 ([M - 1 ? K]^?, 10),

316.26 ([M - 1 ? Na]^?, 18), 295.26 ([M ? 1]^?, 12),

294.31 ([M]^?, 78), 226.13 (100), 136.07 (32).

NH₂

N

H

N

18

ii

17

Elemental analysis for C₁₃H₁₉N₅O₃, Calculated (%), C:

53.23; H: 6.53; N: 23.88.

O

OEt

Found (%), C: 53.59; H: 6.67; N: 23.71.

N

NHNH₂

CH₃

O

N

2-(4-(3-(1H-imidazol-1-yl)propyl)-3-methyl-5-oxo-4,5-dihydro-

1H-1,2,4-triazol-1-yl) acetohydrazide (4) Hydrazine hydrate

(25 mmol) was added to the solution of compound 3

(10 mmol) in absolute ethanol, and the mixture was heated

under reﬂux for 10 h. On cooling the reaction mixture to

room temperature, a white solid appeared. The crude product

was ﬁltered off and recrystallized from butylacetate:dieth-

ylether (1:2) to afford the desired compound. Yield 33 %, mp

172–173 °C. IR (KBr, t, cm^-1): 3339 (NH₂), 3339 (NH),

1653 (C=O). ¹H NMR (DMSO-d₆, d ppm): 4.27 (s, 3H, CH₃),

5.70 (brs, 2H, CH₂), 5.95 (brs, 4H, 2CH₂), 6.37 (s, 2H, CH₂),

6.50 (brs, 2H, NH₂exch. D₂O), 9.06 (s, 1H, ArH), 9.40 (s,

CH₃

O

N

iii

H

N

19

20

iv

O

21a: Ar=

N

1H, ArH), 9.86 (s, 1H, ArH), 9.22 (s, 1H, NH exch. D₂O). ¹³

C

NHN CHAr

HO

NMR (DMSO-d₆, d ppm): 11.71 (CH₃), 30.54 (2CH₂), 44.10

(CH₂), 46.63 (CH₂), 120.16 (CH), 128.63 (2CH), 144.69

(triazole C-5), 154.63 (triazole C-3), 166.87 (C=O). EI MS

m/z (%): 317.27 ([M - 1 ? K]^?, 10), 316.26 ([M -

2 ? K]^?, 22), 228.02 (29), 148.96 (78), 123.93 (100).

Elemental analysis for C₁₁H₁₇N₇O₂, Calculated (%), C:

47.30; H: 6.14; N: 35.10.

CH₃

O

N

OCH₃

N

21b: Ar=

21c: Ar=

H

OCH₃

N

OH

21a-c

Found (%), C: 47.62; H: 6.33; N: 35.47.

Scheme 5 Synthesis of compounds 18–21a-c. i pyridine-4-carbal-

dehyde, ii ethyl bromoacetate, iii hydrazine hydrate, vi suitable

aldehyde

2-({4-[3-(1H-imidazol-1-yl)propyl]-3-methyl-5-oxo-4,5-dihy-

dro-1H-1,2,4-triazol-1-yl}acetyl)-N-phenylhydrazinecarbothi-

oamide (5) The mixture of compound 4 (10 mmol) and

phenylisothiocyanate (10 mmol) in absolute ethanol was

reﬂuxed for 5 h. Upon cooling the reaction content to room

temperature, a white solid formed. This crude product was

ﬁltered and recrystallized from ethanol to afford the desired

compound. Yield 54 %, mp 112–113 °C. IR (KBr, t, cm^-1):

3331 (NH), 3164 (2NH), 1690 (C=O), 1226 (C=S). ¹H NMR

(DMSO-d₆, d ppm): 2.14 (brs, 3H, CH₃), 3.42 (d, 4H, 2CH₂,

J = 4.2 Hz), 3.86(brs, 4H, 2CH₂), 4.46 (s, 2H, CH₂), 6.98(s,

1H, ArH), 7.35 (brs, 6H, ArH), 7.82 (s, 1H, ArH), 9.66–9.77

Ethyl {4-[3-(1H-imidazol-1-yl)propyl]-3-methyl-5-oxo-4,5-

dihydro-1H-1,2,4-triazol-1-yl}acetate (3) Ethylbromoac-

etate (10 mmol) was added to the mixture of compound 2

(10 mmol) in absolute ethanol, and the reaction mixture

was reﬂuxed for 10 h (the progress of the reaction was

monitored by TLC). Then, the solvent was removed under

reduced pressure, 1 mL of H₂O was added and the organic

phase was extracted with CH₂Cl₂(3 9 40 mL). Combined

organic phases were washed with water (2 9 5 mL) and

dried on Na₂SO₄. The solvent was evaporated under

reduced pressure and the obtained solid was recrystallized

from butylacetate:diethylether (1:2) to afford the desired

product. Yield 54 %, mp 109–110 °C. IR (KBr, t, cm^-1):

(m, 2H, NH exch. D₂O), 10.33 (s, 1H, NH exch. D₂O). ¹³

C

NMR (DMSO-d₆, d ppm): 10.32 (CH₃), 24.53 (CH₂), 41.09

(CH₂), 42.79 (CH₂), 48.54 (CH₂), 120.24 (CH), 124.69

(2CH), 125.08 (2CH), 130.59 (C), 134.21 (2CH), 138.21 (C),

144.23 (triazole C-5), 148.67 (C=O), 161.79 (triazole C-3),

1

1729 (C=O), 1117 (C–O). H NMR (DMSO-d₆, d ppm):

1.18 (s, 3H, CH₃), 2.15 (brs, 5H, CH₃? CH₂), 3.55 (dd,

123

Med Chem Res (2013) 22:4930–4945

4937

Scheme 6 i PhCH2NCS, ii

ethyl bromoacetate, iii

4-chlorophenacyl bromide

O

S

N

NHNH₂

N

NHNH

NHPh

CH₃

O

N

CH₃

O

N

i

H

N

20

22

ii

iii

N

O

SH

N

NHN

S

CH₃

O

N

CH₃

O

N

Cl

H

N

23

24

180.51 (C=S). EI MS m/z (%): 453.21 ([M ? K]^?, 10),

417.39 ([M ? 1]^?, 10), 416.39 ([M]^?, 12), 415.39

([M - 1]^?, 46), 398.37 ([M – 1 - H₂O]^?, 53), 231.06 (31),

226.18 (34), 152.91 (100), 139.95 (16).

102.65 (CH), 102.97 (C) 103.42 (CH), 118.42 (2CH),

137.36 (triazole C-5), 141.14 (triazole C-3), 149.78 (CH),

149.91 (2CH), 150.27 (CH), 155.32 (CH), 156.84 (C),

162.85 (C), 263.78 (C), 164.78 (C=O), 168.30 (C=O). EI

MS m/z (%): 585.32 ([M - 2 ? K]^?, 21), 546.22 ([M - 2]^?,

18), 357.56 (68), 234.21 (100), 123.65 (43).

Elemental analysis for C₁₈H₂₂N₈O₂S, Calculated (%),

C: 52.16; H: 5.35; N: 27.03.

Found (%), C: 52.45; H: 5.37; N: 27.28.

Elemental analysis for C₂₆H₂₅ClN₈O₂S, Calculated (%),

C: 56.88; H: 4.59; N: 20.41.

Found (%), C: 57.21; H: 4.64; N: 20.13.

N⁰-[5-(4-chlorophenyl)-3-phenyl-1,3-thiazol-2(3H)-yli-

dene]-2-{4-[3-(1H-imidazol-1-yl)propyl]-3-methyl-5-oxo-

4,5-dihydro-1H-1,2,4-triazol-1-yl}acetohydrazide (6) 4-

Chloro phenacylbromide (10 mmol) and dried sodium

acetate (16.4 g, 200 mmol) was added to the solution of

compound 5 in absolute ethanol, and the reaction mixture

was reﬂuxed for 14 h. Then, it was cooled to room tem-

perature, poured into ice-cold water while stirring and left

overnight in cold. The formed solid was ﬁltered, washed

with water three times and recrystallized from acetone to

afford compound 6. Yield 27 %, mp 143–144 °C. IR (KBr,

t, cm^-1): 3360 (NH), 3063 (aromatic CH), 1736 and 1749

2-{4-[3-(1H-imidazol-1-yl)propyl]-3-methyl-5-oxo-4,5-

dihydro-1H-1,2,4-triazol-1-yl}-N⁰-(4-oxo-3-phenyl-1,3-

thiazolidin-2-ylidene)acetohydrazide (7) Ethyl bromo-

acetate was added to the solution of compound 5 in abso-

lute ethanol (10 mmol) and the mixture was reﬂuxed in the

presence of dried sodium acetate (16.4 g, 200 mmol) for

10 h. Then, the mixture was cooled to room temperature,

poured into ice-cold water while stirring and left overnight

in cold. The formed solid was ﬁltered, washed with water

three times and recrystallized from diethylether to afford

the pure compound. Yield 36 %, mp 132–133 °C. IR (KBr,

t, cm^-1): 3361 (NH), 3065 (aromatic CH), 1709, 1747 and

1

(2C=O), 1453 (C=N). H NMR (DMSO-d₆, d ppm): 1.85

1

(s, 3H, CH₃), 2.98 (s, 2H, CH₂), 4.53 (brs, 4H, 2CH₂), 5.21

(brs, 2H, CH₂), 7.21 (brs, 4H, ArH), 8.09 (brs, 8H, ArH),

9.70 (s, 1H, NH exch. D₂O). ¹³C NMR (DMSO-d₆, d ppm):

7.56 (CH₃), 39.70 (CH₂), 40.23 (2CH₂), 42.26 (CH₂),

1751 (3C=O), 1450 (C=N). H NMR (DMSO-d₆, d ppm):

1.19 (s, 3H, CH₃), 2.48 (s, 2H, CH₂), 4.13 (brs, 4H, 2CH₂),

4.59 (brs, 4H, 2CH₂), 7.79 (brs, 5H, ArH), 8.72 (brs, 3H,

ArH), 9.72 (s, 1H, NH exch. D₂O). ¹³C NMR (DMSO-d₆, d

123

4938

Med Chem Res (2013) 22:4930–4945

Table 1 Antimicrobial activity of the compounds (lg/mL)

Compound numbers

Microorganisms and MIC

Ec

Yp

Pa

Lm

Ef

Sa

Bc

Ms

Ca

Sc

2

–

125

–

500

250

–

1000

–

3

–

4

125

–

125

31.3

39.9

62.5

125

15.6

3.9

–

5

–

250

–

62.5

1000

–

6

–

7

–

8

–

500

31.25

15.6

–

500

7.81

3.9

125

–

9a

9b

9c

0.97

0.48

0.24

0.97

0.48

0.24

\0.12

1.2

125

–

\0.12

31.3

\0.12

–

0.7

–

8

–

2

62.5

–

9d

9e

–

125

500

31.3

–

500

125

–

1.2

–

62.5

125

–

125

62.5

–

9f

125

–

10

11

12a

12b

13

14

15

18

19

20

21a

21b

21c

22

23

24

Amp.

Strep.

Flu.

–

500

250

–

500

62.5

–

31.3

3.9

0.24

250

125

31.3

125

–

2

–

500

125

250

500

250

125

–

500

–

250

–

250

125

–

125

2

125

\1

–

250

32

[128

4

\8

Ec, E. coli ATCC 35218; Yp, Y. pseudotuberculosis ATCC 911; Pa, P. aeruginosa ATCC 10145; Lm, L. monositogenes ATCC 43251; Ef, E.

faecalis ATCC 29212; Sa, S. aureus ATCC 25923; Bc, B. cereus 709 Roma; Ms, M. smegmatis ATCC 607; Ca, C. albicans ATCC 60193; Sc, S.

cerevisiae RSKK 251, Amp., ampicillin; Strep., streptomycin; Flu., ﬂuconazole; –, no activity of test concentrations

4-[3-(1H-imidazol-1-yl)propyl]-2-[(5-mercapto-4-phenyl-

4H-1,2,4-triazol-3-yl)methyl]-5-methyl-2,4-dihydro-3H-1,

2,4-triazol-3-one (8) A solution of compound 5 (10 mmol)

in ethanol:water (1:1) was reﬂuxed in the presence of 2 N

NaOH for 3 h, then, the resulting solution was cooled to

room temperature and acidiﬁed to pH 4 with 37 % HCl. The

precipitate formed was ﬁltered off, washed with water and

recrystallized from acetone to afford the desired compound.

Yield 44 %, mp 141–142 °C. IR (KBr, t, cm^-1): 3352 (SH),

ppm): 7.86 (CH₃), 39.30 (CH₂), 40.17 (CH₂), 40.57 (CH₂),

43.23 (CH₂), 58.18 (CH₂), 101.55 (2CH), 118.42 (2CH),

137.36 (triazole C-5), 141.14 (triazole C-3), 147.44 (CH),

148.54 (2CH), 151.21 (CH), 156.84 (C), 162.85 (C=O),

164.78 (C=O), 168.30 (C=O). EI MS m/z (%): 506.32

(100), 492.56 (68), 491.49 ([M - 2 ? K]^?, 21), 475.28

([M - 2 ? Na]^?, 13), 44.18 (62), 434.49 ([M – 2 - H₂O],

63), 429.48 ([M – 2 - Na]^?, 41), 413.65 ([M – 2 - K]^?,

12).

1

3078 (aromatic CH), 1709 (C=O). H NMR (DMSO-d₆, d

ppm): 1.18 (s, 3H, CH₃), 2.67 (s, 2H, CH₂), 4.54 (brs, 4H,

Elemental analysis for C₂₀H₂₂N₈O₃S, Calculated (%),

C: 52.85; H: 4.88; N: 24.65.

2CH₂), 4.59 (brs, 2H, CH₂), 7.52 (brs, 5H, ArH), 8.58 (brs,

Found (%), C: 52.89; H: 4.77; N: 24.71.

123

Med Chem Res (2013) 22:4930–4945

4939

3H, ArH), 10.11 (s, 1H, SH exch. D₂O). ¹³C NMR (DMSO-

d₆, d ppm): 7.51 (CH₃), 32.36 (CH₂), 41.67 (CH₂), 42.47

(CH₂), 43.73 (CH₂), 102.53 (2CH), 117.71 (2CH), 136.71

(triazole C-5), 142.34 (triazole C-3), 146.84 (CH), 149.74

(2CH), 150.27 (CH), 157.44 (C), 161.95 (C), 169.80 (C=O).

EI MS m/z (%): 396.45 ([M]^?, 10), 395.25 ([M - 1]^?, 19),

291.43 (100), 158.23 (37).

4-[3-(1H-imidazol-1-yl)propyl]-5-methyl-2-[(4-phenylpi-

perazin-1-yl)methyl]-2,4-dihydro-3H-1,2,4-triazol-3-one

(9c) Yield: 1.00 g, 80 %, mp 102 °C. IR (KBr, t, cm^-1):

1

3027 (ArCH); 1725 (C=O). H NMR (DMSO-d₆, d ppm):

2.13 (s, 5H, CH₃? CH₂), 2.66 (brs, 4H, 2CH₂), 3.08 (s,

4H, 2CH₂), 3.42 (s, 2H, CH₂), 4.50 (s, 4H, 2CH₂), 6.89 (s,

2H, ArH), 7.22 (s, 3H, ArH). ¹³C NMR (DMSO-d₆, d

ppm): 11.86 (CH₃), 30.71 (CH₂), 44.09 (CH₂), 49.03

(CH₂), 50.21 (CH₂), 65.97 (CH₂), 67.37 (CH₂), 82.60

(CH₂), 84.63 (CH₂), ArC: [116.09 (CH), 116.25 (CH),

119.38 (CH), 119.59 (CH), 119.98 (CH), 129.02 (CH),

129.12 (CH), 129.59 (CH), 151.72 (C), 153.79 (C), 154.86

(C=O)]. EI MS m/z (%): 382.35 ([M ? 1]^?, 10), 175.99

(100), 131.88 (13).

Elemental analysis for C₁₈H₂₀N₈OS, Calculated (%), C:

54.53; H: 5.08; N: 28.26.

Found (%), C: 54.59; H: 5.13; N: 28.17.

General method for the synthesis of compounds 9a–c

The suitable amine was added to a solution of compound 2

(10 mmol) in tetrahydrofuran and the mixture was stirred

at room temperature in the presence of formaldehyde

(37 %, 7.4 mL) for 4 h. Then, water was added and kept

overnight in cold conditions. The solid separated was

collected by ﬁltration and recrystallized from ethyl acetate–

petroleum ether (1:2) to yield the target compounds.

Elemental analysis for C₂₀H₂₇N₇O, Calculated (%), C:

62.79; H: 7.13; N: 25.70.

Found (%), C: 63.11; H: 7.27; N: 25.46.

2-{[(2-Furylmethyl)amino]methyl}-4-[3-(1H-imidazol-1-yl)

propyl]-5-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one (9d)

Yield: 0.41 g, 85 %, mp 158 °C. IR (KBr, t, cm^-1): 3258

1

(NH), 3025 (ArCH); 1724 (C=O). H NMR (DMSO-d₆, d

4-[3-(1H-imidazol-1-yl)propyl]-5-methyl-2-(morpholin-4-

ylmethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (9a) Yield:

0.53 g, 52 %, mp 123 °C. IR (KBr, t, cm^-1): 1712 (C=O),

ppm): 2.10 (brs, 5H, CH₂? CH₃), 3.41–3.52 (m, 4H,

2CH₂), 3.39 (brs, 2H, CH₂), 6.88 (s, 2H, ArH), 7.24 (s, 2H,

ArH), 7.67 (s, 2H, ArH), 11.42 (s, 1H, NH, D₂O exch.). ¹³

1

C

1117 (C–O). H NMR (DMSO-d₆, d ppm): 2.13 (s, 5H,

NMR (DMSO-d₆, d ppm): 12.04 (CH₃), 30.72 (CH₂), 30.82

(CH₂), 44.10 (2CH₂), 67.36 (C), ArC: [102.23 (C), 119.96

(3CH), 129.09 (3CH)], 145.06 (C=O). EI MS m/z (%):

320.19 (53), 316,45 ([M]^?, 25), 119.30 (100).

Elemental analysis for C₁₅H₂₀N₆O, Calculated (%), C:

56.94; H: 6.37; N: 26.56.

CH₃? CH₂), 2.48 (brs, 4H, 2CH₂), 3.23 (brs, 6H, 3CH₂),

3.97 (t, 2H, CH₂, J = 6.5 Hz), 4.66 (s, 2H, CH₂), 6.88 (s,

1H, ArH), 7.23 (s, 1H, ArH), 7.67 (s, 1H, ArH). ¹³C NMR

(DMSO-d₆, d ppm): 11.85 (CH₃), 30.69 (CH₂), 44.08

(CH₂), 49.90 (CH₂), 50.61 (CH₂), 66.16 (CH₂), 66.91

(CH₂), 82.59 (CH₂), 84.61 (CH₂), ArC: [119.97 (CH),

129.11 (CH), 138.95 (CH), 143.97 (C), 154.86 (C=O)]. EI

MS m/z (%): 407.09 (54), 306.23 ([M]^?, 59), 215.30 (100).

Elemental analysis for C₁₄H₂₂N₆O₂, Calculated (%), C:

54.89; H: 7.24; N: 27.43.

Found (%), C: 57.27; H: 6.42; N: 26.38.

4-[3-(1H-imidazol-1-yl)propyl]-5-methyl-2-{[(2-piperazin-

1-ylethyl)amino]methyl}-2,4-dihydro-3H-1,2,4-triazol-3-

one (9e) Yield: 0.38 g, 75 %, mp 142 °C. IR (KBr, t,

Found (%), C: 55.22; H: 7.46; N: 27.21.

1

cm^-1): 3258, 3174 (2NH), 3014 (ArCH), 1694 (C=O). H

NMR (DMSO-d₆, d ppm): 1.75 (s, 3H, CH₃), 2.13 (s, 6H,

3CH₂), 2.49 (brs, 2H, CH₂), 3.39 (brs, 10H, 5CH₂), 3.97 (s,

2H, CH₂), 4.42 (brs, 2H, 2NH), 6.88 (s, 1H, Ar), 7.24 (s,

1H, ArH), 7.67 (s, 1H, ArH). ¹³C NMR (DMSO-d₆, d

ppm): 11.62 (CH₃), 30.46 (2CH₂), 42.38 (2CH₂), 44.15

(2CH₂), 49.84 (CH), 65.49 (2CH₂), 67.77 (2CH₂), 104.99

(C), ArC: [128.75 (3CH)], 154.93 (C=O). EI MS m/z (%):

350.76 ([M ? 2]^?, 12), 350.19 (45), 257.43 (100).

Elemental analysis for C₁₆H₂₈N₈O, Calculated (%), C:

55.15; H: 8.10; N: 32.16.

4-[3-(1H-imidazol-1-yl)propyl]-5-methyl-2-(piperidin-1-

ylmethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (9b) Yield:

0.81 g, 78 %, mp 110 °C. IR (KBr, t, cm^-1): 3027 (ArCH),

1

1725 (C=O). H NMR (DMSO-d₆, d ppm): 1.41 (s, 5H,

CH₃? CH₂), 2.12 (s, 4H, 2CH₂), 2.45 (brs, 4H, 2CH₂),

3.94 (brs, 4H, 2CH₂), 3.97 (t, 2H, CH₂, J = 6.8 Hz), 4.67

(s, 4H, 2CH₂), 6.88 (s, 1H, ArH), 7.22 (s, 1H, ArH), 7.67 (s,

1H, ArH). ¹³C NMR (DMSO-d₆, d ppm): 11.79 (CH₃),

24.15 (CH₂), 26.19 (CH₂), 30.69 (CH₂), 44.18 (CH₂), 50.04

(CH₂), 51.48 (CH₂), 66.98 (CH₂), 82.57 (CH₂), 84.64

(CH₂), ArC: [119.98 (CH), 129.00 (CH), 139.20 (CH),

143.70 (C), 154.85 (C=O)]. EI MS m/z (%): 524.12 (68),

303.40 ([M - 1]^?, 23), 297.48 (35), 227.45 (100).

Elemental analysis for C₁₅H₂₄N₆O, Calculated (%), C:

59.19; H: 7.95; N: 27.61.

Found (%), C: 55.11; H: 8.18; N: 32.45.

6-[({4-[3-(1H-imidazol-1-yl)propyl]-3-methyl-5-oxo-4,5-dihy

dro-1H-1,2,4-triazol-1-yl}methyl)amino]-3,3-dimethyl-7-oxo-

4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid (9f)

Yield: 0.41 g, 79 %, mp 185 °C. IR (KBr, t, cm^-1): 3568

Found (%), C: 59.43; H: 7.67; N: 27.42.

123

4940

Med Chem Res (2013) 22:4930–4945

1

(OH), 3254 (NH), 3109 (ArCH), 1754, 1694 2(C=O). H

NMR (DMSO-d₆, d ppm): 1.13 (brs, 6H, 2CH₃), 1.49 (brs,

5H, CH₃? CH₂), 2.12 (brs, 6H, 3CH₂), 6.98 (s, 1H, ArH),

7.27 (s, 1H, ArH), 7.85 (s, 1H, ArH). ¹³C NMR (DMSO-d₆,

d ppm): 9.09 (CH₃), 11.66 (CH₃), 11.81 (CH₃) 30.43

(CH₂), 44.38 (CH₂), 46.15 (CH₂), 56.74 (CH₂), 58.12 (C),

67.28 (C), 98.51 (CH), 101.89 (CH), 104.99 (CH), ArC:

[120.31 (2CH), 128.04 (CH)], 144.70 (C=O), 145.50

(C=O), 153.91 (C=O). EI MS m/z (%): 458 ([M ? Na]^?,

14), 452 (54), 436 ([M ? 1]^?, 65), 230.43 (100).

Elemental analysis for C₁₈H₂₅N₇O₄S, Calculated (%),

C: 49.65; H: 5.79; N: 22.51.

118.36 (CH), 118.43 (CH), 137.10 ve 137.33 (C), 144.40

(C), 144.61 (C), 151.33 (C), 156.12 (C=O)]. EI MS m/

z (%): 340.49 ([M ? 1 ? Na]^?, 20), 339.49 ([M ? Na]^?,

100), 261.40 (10), 249.39 (12), 198.27 (11).

Elemental analysis for C₁₅H₁₇FN₆O, Calculated (%), C:

56.95; H: 5.42; N: 26.57.

Found (%), C: 57.17; H: 5.75; N: 26.43.

General method for the synthesis of compounds 12a and b

A solution of compound 11 (10 mmol) in ethanol was

reﬂuxed with 2,6-dichlorobenzaldehyde (for 12a) or 4-bro-

mobenzaldehyde (for 12b) for 6 h. On cooling the reaction

mixture to room temperature, a solid appeared. This crude

product was recrystallized from ethanol–water (1:2) (for

12a) or ethanol (for 12b) to afford the desired product.

Found (%), C: 49.71; H: 5.87; N: 22.46.

4-[3-(1H-imidazol-1-yl)propyl]-5-methyl-2-(2-ﬂuoro-4-nitro-

phenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (10) A solu-

tion of compound 2 (1.71 g, 10 mmol) and metallic sodium

(0.19 g, 10 mmol) in absolute ethanol (10 mL) was

reﬂuxed for 2 h. Then, the reaction mixture was allowed to

cool to room temperature, 3,4-diﬂuoronitrobenzene

(10 mmol) was added into it reﬂuxed for an additional 8 h

(TLC controlled). The reaction content was poured into

ice-water. The precipitated product was ﬁltered off and

recrystallized from ethanol. Yield: 1.63 g, 47 %, mp

83 °C. IR (KBr, t, cm^-1): 1334 and 1495 (NO₂). ¹H NMR

(DMSO-d₆, d ppm): 1.33–1.40 (m, 5H, CH₃? CH₂), 4.35

(q, 4H, 2CH₂, J = 6.3 Hz), 7.35 (t, 2H, ArH, J = 8.6 Hz),

8.08–8.12 (m, 4H, ArH). ¹³C NMR (DMSO-d₆, d ppm):

14.92 (CH₃), 66.04 (3CH₂), ArC: [112.32 (CH), 112.78

(CH), 113.00 (CH), 114.56 (CH), 122.16 (2CH), 141.0 (C),

148.45 (2C), 153.00 (C), 153.20 (C), 153.37 (C=O)]. EI

MS m/z (%): 348.21 ([M ? 2]^?, 21), 347.21 ([M ? 1]^?,

100), 279.09 (25).

2-(4-{[(2,6-Dichlorophenyl)methylene]amino}-2-ﬂuoro-

phenyl)-4-[3-(1H-imidazol-1-yl)propyl]-5-methyl-2,4-dihy-

dro-3H-1,2,4-triazol-3-one (12a) Yield: 2.50 g, 53 %,

mp 84 °C. IR (KBr, t, cm^-1): 3018 (ArCH), 1714 (C=O),

1

1603 (C=N). H NMR (DMSO-d₆, d ppm): 1.34 (s, 3H,

CH₃), 5.03 (d, 2H, CH₂, J = 2.0 Hz), 4.06–4.16 (m, 4H,

2CH₂), 7.14–7.37 (m, 4H, ArH), 7.47–7.59 (m, 4H, ArH),

8.74 (s, 1H, N=CH). ¹³C NMR (DMSO-d₆, d ppm): 15.25

(CH₃), 65.21 (3CH₂), ArC: [109.26 (CH), 109.64 (CH),

115.65 (CH), 118.79 (CH), 118.85 (CH), 129.82 (2CH),

132.45 (2CH), 132.92 (C), 134.69 (C), 143.97 (C), 144.11

(C), 146.11 (C), 146.22 (C), 146.43 (C), 150.07 (C), 154.91

(C=O), 156.39 (N=CH)]. EI MS m/z (%): 473.33

([M ? 1]^?, 100), 476.67 (28).

Elemental analysis for C₂₂H₁₉Cl₂FN₆O, Calculated (%),

C: 55.82; H: 4.05; N: 17.76.

Elemental analysis for C₁₅H₁₅FN₆O₃, Calculated (%),

C: 52.02; H: 4.37; N: 24.27.

Found (%), C: 56.11; H: 4.09; N: 17.84.

Found (%), C: 52.35; H: 7.64; N: 24.13.

2-(4-{[(4-Bromophenyl)methylene]amino}-2-ﬂuorophenyl)-

4-[3-(1H-imidazol-1-yl)propyl]-5-methyl-2,4-dihydro-3H-

1,2,4-triazol-3-one (12b) A solution of compound 12

(10 mmol) in ethanol was reﬂuxed with 4-bromobenzal-

dehyde for 6 h. On cooling the reaction mixture to room

temperature, a solid appeared. This crude product was re-

crystallized from ethanol to give the desired product.

Yield: 2.79 g, 57 %, mp 89 °C. IR (KBr, t, cm^-1): 3021

(ArCH), 1712 (C=O), 1610 (C=N). ¹H NMR (DMSO-d₆, d

ppm): 3.51 (s, 5H, CH₃? CH₂), 5.54 (s, 2H, CH₂),

6.26–6.29 (brs, 2H, CH₂), 9.31–9.50 (m, 4H, ArH),

9.89–10.02 (m, 6H, ArH), 10.81 (s, 1H, N=CH). ¹³C NMR

(DMSO-d₆, d ppm): 15.29 (CH₃), 65.13 (3CH₂), ArC:

[109.23 (CH), 109.61 (CH), 115.55 (CH), 119.04 (CH),

125.55 (C), 131.02 (CH), 131.93 (CH), 132.32 (CH),

132.56 (CH), 133.00 (CH), 135.86 (C), 144.52 (C), 145.70

(C), 145.91 (C), 150.03 (C), 154.90 (C=O), 159.29

(N=CH)]. EI MS m/z (%): 483.30 ([M^?], 22), 393.63 (18),

2-(4-Amino-2-ﬂuorophenyl)-4-[3-(1H-imidazol-1-yl)propyl]-

5-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one (11) Pd–C

(5 mmol) catalyst was added to the solution of compound

11 (10 mmol) in butanol, and the mixture was reﬂuxed in

the presence of hydrazine hydrate (50 mmol) for 8 h. The

progress of the reaction was monitored by TLC. After

completion of the reaction, the catalyst was separated by

ﬁltration and the reaction solvent was evaporated under

reduced pressure. The crude product formed was recrys-

tallized from ethanol. IR (KBr, t, cm^-1): 3387, 3487

1

(NH₂), 3013 (ArCH). H NMR (DMSO-d₆, d ppm): 0.84

(brs, 3H, CH₃), 1.20–1.42 (m, 6H, 3CH₂), 4.88 (s, 2H,

NH₂, D₂O exch.), 6.27–6.43 (m, 4H, ArH), 6.44–7.82

(t, 2H, ArH, J = 9.1 Hz). ¹³C NMR (DMSO-d₆, d ppm):

15.44 (CH₃), 19.32 (CH₂), 61.10 (CH₂), 66.21 (CH₂), ArC:

[102.59 (CH), 103.01 (CH), 110.00 (CH), 110.05 (CH),

123

Med Chem Res (2013) 22:4930–4945

4941

317.54 (29), 274.43 (25), 273.49 (100), 249.40 (70), 188.39

(74), 160.29 (80), 108.23 (40).

(33), 535.67 (23), 521.70 (20), 491.68 (25), 477.66 (23),

475.66 (32), 469.72 (34).

Elemental analysis for C₁₄H₂₂N₆O₂, Calculated (%), C:

54.89; H: 7.24; N: 27.43.

Elemental analysis for C₂₃H₂₄FN₇OS, Calculated (%),

C: 59.39; H: 4.78; N: 19.37.

Found (%), C: 55.22; H: 7.46; N: 27.21.

Found (%), C: 59.66; H: 4.84; N: 19.12.

N-benzyl-N⁰-(3-ﬂuoro-4-{4-[3-(1H-imidazol-1-yl)propyl]-

3-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl}phenyl)

thiourea (13) The mixture of compound 12 (10 mmol)

and benzyl isothiocyanate (10 mmol) was allowed to reﬂux

in absolute ethanol for 7 h. Then, the solution was cooled

to room temperature and a solid appeared. This product

was ﬁltered off and recrystallized from ethanol. Yield:

2.9 g, 61 %, mp 193 °C. IR (KBr, t, cm^-1): 3192, 3248

(NH), 1230 (C=S). ¹H NMR (DMSO-d₆, d ppm): 1.31

(s, 3H, CH₃), 3.34 (s, 2H, CH₂), 4.05 (q, 4H, 2CH₂,

J = 3.0 Hz), 4.71 (s, 2H, CH₂), 7.27–7.40 (m, 1H, ArH),

8.12 (s, 1H, NH, D₂O exch.), 9.53 (s, 1H, NH, D₂O exch.).

¹³C NMR (DMSO-d₆, d ppm): 15.33 (CH₃), 47.86 (2CH₂),

65.13 (2CH₂), ArC: [113.03 (CH), 113.44 (CH), 115.33

(CH), 120.92 (CH), 127.53 (2CH), 128.05 (2CH), 128.94

(2CH), 132.59 (CH), 132.77 (C), 139.74 (C), 144.03 (C),

144.25 (C), 149.17 (C)], 154.00 (C=O), 181.61 (C=S). EI

MS m/z (%): 466.34 ([M ? 1]^?, 20), 343.13 (31), 324.17

(18), 306.15 (20), 305.15 (100), 291.13 (17), 223.93 (23),

176,88 (37), 116.81 (31).

2-(4-Amino-2-ﬂuorophenyl)-5-methyl-2,4-dihydro-3H-1,2,

4-triazol-3-one (15)

A

mixture of compound 14

(10 mmol) and 4-chloro phenacylbromide (20 mmol) in

absolute ethanol was reﬂuxed in the presence of dried

sodium acetate (50 mmol) for 10 h. Then, the mixture was

poured into ice-water. The precipitated product was ﬁltered

off and recrystallized from ethanol. Yield: 1.50 g, 62 %,

mp 119 °C. IR (KBr, t, cm^-1): 1450 (C=N), 1527 (NO₂).

¹H NMR (DMSO-d₆, d ppm): 2.14 (s, 3H, CH₃), 5.52 (s,

2H, NH₂, D₂O exch.), 8.26 (q, 1H, NH, J = 8.6 Hz D₂O

exch.). ¹³C NMR (DMSO-d₆, d ppm): 20.98 (CH₃), 124.68

(2CH), 130.00 (CH), 139.11 (2C), 150.98 (C), 170.61 (C),

193.05 (C=O). EI MS m/z (%): 226.23 ([M ? H₂O]^?, 13),

208.15 ([M]^?, 10), 169.16 (100), 108.20 (28).

Elemental analysis for C₂₃H₂₄FN₇OS, Calculated (%),

C: 51.92; H: 4.36; N: 26.91.

Found (%), C: 52.35; H: 4.49; N: 26.64.

5-Methyl-4-[(pyridin-4-ylmethylene)amino]-2,4-dihydro-

3H-1,2,4-triazol-3-one (18) The mixture of compound 17

(10 mmol) and 4-pyridinecarboxaldehyde (10 mmol) in

absolute ethanol was irradiated with microwave (150 W,

160 °C) for 30 min. After completion of reaction (moni-

tored by TLC), the formed solid was ﬁltered and washed

with diethylether. The obtained crude product was recrys-

tallized from ethanol. Yield 99 %, mp 129–130 °C. IR

Elemental analysis for C₂₃H₂₄FN₇OS, Calculated (%),

C: 59.34; H: 5.20; N: 21.06.

Found (%), C: 59.42; H: 5.37; N: 21.33.

2-{5-[(3-Benzyl-4-oxo-1,3-thiazolidin-2-ylidene)amino]-2-

ﬂuorophenyl}-4-[3-(1H-imidazol-1-yl)propyl]-5-methyl-2,

1

4-dihydro-3H-1,2,4-triazol-3-one (14)

A

mixture of

(KBr, t, cm^-1): 3166 (NH), 1721 (C=O), 1602 (C=N). H

compound 14 (10 mmol) and ethyl bromoacetate in abso-

lute ethanol was allowed to reﬂux in the presence of dried

sodium acetate (50 mmol) for 10 h. Then, the mixture was

poured into ice-water. The precipitated product was ﬁltered

off and recrystallized from acetone. Yield: 2.50 g, 50 %,

mp 79 °C. IR (KBr, t, cm^-1): 1726 (C=O), 1600 (C=N).

¹H NMR (DMSO-d₆, d ppm): 1.32 (brs, 5H, CH₃? CH₂),

3.38 (s, 2H, CH₂), 4.03–4.10 (m, 4H, 2CH₂), 4.89 (brs, 2H,

CH₂), 6.66–6.83 (m, 3H, ArH), 7.06–7.10 (m, 2H, ArH),

7.12–7.34 (m, 6H, ArH). ¹³C NMR (DMSO-d₆, d ppm):

15.32 (CH₃), 33.24 (CH₂), 46.07 (2CH₂), 65.14 (2CH₂),

ArC: [109.88 (CH), 110.27 (CH), 116.01 (CH), 116.07

(CH), 117.41 (CH), 117.48 (CH), 127.52 (CH), 128.07

(CH), 128.13 (CH), 128.41 (CH), 129.13 (CH), 136.81 (C),

141.69 (C), 143.71 (C), 149.90 (C),154.77 (C), 156.46

(C=N), 172.67 (C=O), 181.66 (C=O)]. EI MS m/z (%):

505.70 ([M]^?, 33), 529.60 ([M ? 1 ? Na]^?, 20), 543.55

([M ? K]^?, 16), 593.80 (30), 589.73 (34), 588.79 (100),

579.72 (27), 577.65 (42), 565.70 (22), 563.70 (32), 549.75

NMR (DMSO-d₆, d ppm): 2.26 (s, 3H, CH₃), 7.71 (s, 2H,

ArH), 8.66 (s, 2H, ArH), 9.75 (s, 1H, N=CH), 11.91 (s, 1H,

NH exch. D₂O). ¹³C NMR (DMSO-d₆, d ppm): 11.24

(CH₃), 122.47 (2CH), 142.36 (triazole C-3), 144.56 (C),

151.198 (2CH), 161.15 (triazole C-5), 168.33 (N=CH). EI

MS m/z (%): 226.13 ([M ? Na]^?, 10), 204.03 ([M ? 1]^?,

50), 181.07 ([M ? 1 - H₂O]^?, 10), 164.05 (12), 148.97

(14), 135.95 (28), 105.03 (100).

Elemental analysis for C₉H₉N₅O, Calculated (%), C:

53.20; H: 4.46; N: 34.47.

Found (%), C: 53.47; H: 4.44; N: 34.15.

Ethyl (3-methyl-5-oxo-4-[(pyridin-4-ylmethylene)amino]-

4,5-dihydro-1H-1,2,4-triazol-1-yl)acetate (19) Ethylbro-

moacetate (10 mmol) was added to the solution of com-

pound 18 (10 mmol) in absolute ethanol and the reaction

mixture was reﬂuxed for 10 h. After evaporating the sol-

vent under reduced pressure, an oily product was obtained.

1 mL of H₂O was added into it and the formed solid was

123

4942

Med Chem Res (2013) 22:4930–4945

separated by ﬁltration. This crude product was washed with

diethyl ether to afford the desired product. Yield 98 %, mp

135–136 °C. IR (KBr, t, cm^-1): 1747 and 1709 (2C=O),

CH₂), 7.32 (brs, 4H, ArH), 8.31 (s, 1H, NH D₂O exch.) 8.92

(s, 1H, N=CH), 9.93 (s, 1H, N=CH). ¹³C NMR (DMSO-d₆, d

ppm): 11.51 (CH₃), 47.03 (CH₂), 122.43 (2CH), 112.21

(2CH), 112.79 (CH), 124.65 (2CH), 127.31 (CH), 142.21

(C), 144.15 (triazole C-3), 144.41 (C), 145.17 (N=CH),

147.39 (triazole C-5), 150.15 (C), 150.36 (C=O), 163.08

(N=CH), 167.87 (C=O). EI MS m/z (%): 380.35 ([M ? 1]^?,

10), 263.15 (55), 241.98 (13), 148.86 (100), 124.00 (90).

Elemental analysis for C₁₈H₁₇N₇O₃, Calculated (%), C:

56.99; H: 4.52; N: 25.84.

1

1592 (C=N), 1215 (C–O). H NMR (DMSO-d₆, d ppm):

1.21 (d, 3H, CH₃, J = 6.2 Hz), 2.35 (brs, 3H, CH₃), 4.16

(brs, 2H, CH₂), 4.62 (s, 2H, CH₂), 7.80 (s, 2H, ArH), 8.73

(brs, 2H, ArH), 9.74 (s, 1H, N=CH). ¹³C NMR (DMSO-d₆,

d ppm): 11.57 (CH₃), 14.70 (CH₃), 46.97 (CH₂), 62.00

(CH₂), 122.17 (2CH), 141.31 (triazole C-3), 144.54 (C),

150.20 (2CH), 151.20 (triazole C-5), 152.18 (N=CH),

168.33 (C=O). EI MS m/z (%): 312.24 (25), 290.22 ([M]^?,

10), 105.00 (100).

Found (%), C: 57.17; H: 4.41; N: 25.62.

Elemental analysis for C₁₃H₁₅N₅O₃, Calculated (%), C:

53.97; H: 5.23; N: 24.21.

N⁰-[(4-methoxyphenyl)methylene]-2-(3-methyl-5-oxo-4-[(pyri-

din-4-ylmethylene)amino]-4,5-dihydro-1H-1,2,4-triazol-1-yl)

acetohydrazide (21b) Yield 57 %, mp 224–225 °C. IR

(KBr, t, cm^-1): 3329 (NH), 3106–3040 (ArCH), 2977

(aliphatic-CH), 1716, 1696 (2C=O), 1416, 1477 (N=CH).

¹H NMR (DMSO-d₆, d ppm): 2.35 (s, 3H, CH₃), 3.85 (brs,

3H, OCH₃), 4.76 (s, 2H, CH₂), 6.97 (d, 2H, ArH,

J = 7.8 Hz), 7.63 (d, 2H, ArH, J = 8.2 Hz), 7.91 (s, 3H,

ArH), 8.12 (s, 1H, ArH), 8.72 (s, 1H, N=CH), 11.51 (s, 1H,

N=CH). ¹³C NMR (DMSO-d₆, d ppm): 11.54 (CH₃), 47.12

(CH₂), 56.20 (OCH₃), 122.44 (2CH), 112.21 (2CH), 112.83

(CH), 124.65 (2CH), 127.26 (CH), 141.21 (C), 144.10

(triazole C-3), 144.10 (N=CH), 146.65 (triazole C-5),

151.42 (C), 151.46 (C=O), 162.18 (N=CH), 167.17 (C=O).

EI MS m/z (%): 441.31 (13), 395.25 ([M ? 2]^?, 18),

394.32 ([M ? 1]^?, 24), 379.30 (46), 376.23 ([M ? 1 -

H₂O]^?, 10), 343.26 (84), 327.24 (69), 324.23 (100).

Elemental analysis for C₁₉H₁₉N₇O₃, Calculated (%), C:

58.01; H: 4.87; N: 24.92.

Found (%), C: 54.24; H: 5.16; N: 24.48.

2-(3-Methyl-5-oxo-4-[(pyridin-4-ylmethylene)amino]-4,5-dihy-

dro-1H-1,2,4-triazol-1-yl)acetohydrazide (20) Hydrazine

hydrate (25 mmol) was added to the solution of compound

19 (10 mmol) in absolute ethanol, and the mixture was

reﬂux for 10 h. On cooling the reaction mixture to room

temperature, a white solid appeared. The crude product was

ﬁltered off and recrystallized from ethanol to give the

desired compound. Yield 43 %, mp 207–208 °C. IR (KBr,

1

t, cm^-1): 3300 and 3263 (NH₂? NH), 1684 (C=O). H

NMR (DMSO-d₆, d ppm): 2.03 (s, 3H, CH₃), 4.50 (s, 2H,

CH₂), 6.79 (brs, 2H, NH₂exch. D₂O), 7.03 (s, 1H, ArH),

7.15 (brs, 3H, ArH), 7.56 (t, 1H, NH, exch. D₂O,

J = 16.0 Hz), 8.07 (s, 1H, N=CH). ¹³C NMR (DMSO-d₆,

d ppm): 8.76 (CH₃), 49.65 (CH₂), 111.58 (2CH), 141.14

(triazole C-3), 145.84 (C), 148.54 (2CH), 151.36 (triazole

C-5), 162.85 (N=CH), 164.78 (C=O). EI MS m/z (%):

316.26 ([M ? 1 ? K]^?, 18), 228 (14), 148.96 (77), 123.93

(98), 113.93 (68), 105.00 (100).

Found (%), C: 58.13; H: 4.89; N: 24.77.

N⁰-[(3-Hydroxy-4-methoxyphenyl)methylene]-2-(3-methyl-

5-oxo-4-[(pyridin-4-ylmethylene)amino]-4,5-dihydro-1H-1,

2,4-triazol-1-yl)acetohydrazide (21c) Yield 57 %, mp

221–222 °C. IR (KBr, t, cm^-1): 3217 (OH), 3095 (ArCH),

2982 (aliphatic-CH), 1722, 1684 (2C=O), 1411, 1478

Elemental analysis for C₁₁H₁₂N₇O₂, Calculated (%), C:

48.00; H: 4.76; N: 35.62.

Found (%), C: 48.28; H: 4.53; N: 35.61.

1

General method for the synthesis of compounds 21a–c

(N=CH). H NMR (DMSO-d₆, d ppm): 2.34 (s, 3H, CH₃),

3.79 (brs, 3H, OCH₃), 4.86 (s, 2H, CH₂), 6.89–6.99 (m, 3H,

ArH), 7.17 (s, 1H, ArH), 7.84 (s, 1H, ArH), 8.30 (d, 1H,

N=CH, J = 6.2 Hz), 8.94 (d, 2H, ArH, J = 4.8 Hz), 9.90

(s, 1H, NH D₂O exch.), 11.56 (s, 1H, N=CH). ¹³C NMR

(DMSO-d₆, d ppm): 11.53 (CH₃), 47.05 (CH₂), 56.24

(OCH₃), 122.41 (2CH), 112.98 (2CH), 112.79 (CH),

124.65 (2CH), 137.31 (C), 144.15 (triazole C-3), 144.41

(C), 145.17 (N=CH), 147.39 (triazole C-5), 150.15 (C),

150.36 (C=O), 163.08 (N=CH), 167.87 (C=O). EI MS

m/z (%): 411.32 ([M ? 2]^?, 13), 410.32 ([M ? 1]^?, 58),

306.20 (13), 214.91 (12), 167.05 (13).

The mixture of compound 20 (10 mmol) and the suitable

aldehyde in absolute ethanol was reﬂuxed (10 mmol) for

4 h. Then, the reaction content was allowed to reach to

room temperature, and a solid appeared. This crude product

was ﬁltered off and recrystallized from acetone to obtain

the desired compound.

N⁰-[(2-Hydroxyphenyl)methylene]-2-(3-methyl-5-oxo-4-

[(pyridin-4-ylmethylene)amino]-4,5-dihydro-1H-1,2,4-tria-

zol-1-yl)acetohydrazide (21a) Yield 43 %, mp 235–

236 °C. IR (KBr, t, cm^-1): 1701 and 1689 (2C=O), 1586 and

Elemental analysis for C₁₉H₁₉N₇O₄, Calculated (%), C:

55.74; H: 4.68; N: 23.95.

1

1583 (2C=N), 1250 (C–O). H NMR (DMSO-d₆, d ppm):

2.35 (s, 3H, CH₃), 4.53 (s, 1H, OH D₂O exch.), 4.88 (s, 2H,

Found (%), C: 55.67; H: 4.74; N: 24.12.

123

Med Chem Res (2013) 22:4930–4945

4943

2-[(3-Methyl-5-oxo-4-[(pyridin-4-ylmethylene)amino]-4,5-

dihydro-1H-1,2,4-triazol-1-yl)acetyl]-N-phenylhydrazine

carbothioamide (22) The mixture of compound 20

(10 mmol) and phenylisothiocyanate (10 mmol) in abso-

lute ethanol was reﬂuxed for 10 h. On cooling the reaction

content to room temperature, a white solid formed. This

crude product was ﬁltered and recrystallized from ethanol

to afford the desired compound. Yield 85 %, mp

211–212 °C. IR (KBr, t, cm^-1): 3366 (2NH), 3323 (NH),

(16.4 g, 200 mmol) for 14 h. Then, the mixture was cooled

to room temperature, poured into ice-cold water while

stirring and left overnight in cold. The formed solid was

ﬁltered, washed with water three times and recrystallized

from acetone to afford compound 24. Yield 71 %, mp

181–182 °C. IR (KBr, t, cm^-1): 1743 and 1713 (2C=O),

1

1581 (C=N), 1215 (C–O). H NMR (DMSO-d₆, d ppm):

2.09 (s, 3H, CH₃), 5.15 (s, 2H, CH₂), 6.98 (s, 1H, ArH),

7.34 (brs, 4H, ArH), 7.53 (brs, 5H, ArH), 7.81 (s, 2H, ArH),

8.73 (s, 2H, ArH), 9.74 (s, 1H, N=CH), 10.61 (s, 1H, NH

exch. D₂O). ¹³C NMR (DMSO-d₆, d ppm): 11.69 (CH₃),

46.23 (CH₂), 120.17 (2CH), 121.34 (C), 124.15 (CH),

126.45 (2CH), 127.23 (CH), 128.88 (2CH), 130.21 (2CH),

133.54 (C), 139.65 (2C), 140.43 (triazole C-3), 145.48 (C),

149.46 (2CH), 151.19 (triazole C-5), 158.64 (N=CH),

161.96 (N=CH), 168.93 (C=O). EI MS m/z (%): 584.59

([M ? K]^?, 10), 567.54 ([M ? Na]^?, 11), 545.83 ([M]^?,

10), 399.52 (26), 385.55 (26), 301.48 (100), 217.21 (68).

Elemental analysis for C₂₆H₂₁ClN₈O₂S, Calculated (%),

C: 57.30; H: 3.88; N: 20.58.

1

1682 and 1695 (C=O). H NMR (DMSO-d₆, d ppm): 2.33

(s, 3H, CH₃), 4.54 (s, 2H, CH₂), 7.18 (s, 1H, ArH), 7.39

(brs, 4H, ArH), 7.39 (s, 2H, ArH), 8.72 (s, 2H, ArH), 9.74

(brs, 2H, NH exch. D₂O), 9.79 (s, 1H, NH exch. D₂O),

10.36 (s, 1H, N=CH). ¹³C NMR (DMSO-d₆, d ppm): 11.63

(CH₃), 47.03 (CH₂), 122.17 (CH), 126.10 (CH), 126.75

(CH), 128.88 (2CH), 139.65 (C), 141.19 (triazole C-3),

144.40 (C), 150.48 (3CH), 151.24 (triazole C-5), 151.96

(2CH), 166.93 (C=O), 181.43 (C=S). EI MS m/z (%):

412.43 ([M ? 2]^?, 56), 392.04 ([M - H₂O]^?, 22), 327.41

(76), 119.32 (100).

Elemental analysis for C₁₈H₁₈N₈O₂S, Calculated (%),

C: 52.67; H: 4.42; N: 27.30.

Found (%), C: 57.54; H: 3.93; N: 20.49.

Found (%), C: 52.89; H: 4.26; N: 27.41.

Antimicrobial activity

2-[(5-Mercapto-4-phenyl-4H-1,2,4-triazol-3-yl)methyl]-5-

methyl-4-[(pyridin-4-ylmethylene)amino]-2,4-dihydro-3H-

1,2,4-triazol-3-one (23) A solution of compound 22

(10 mmol) in ethanol:water (1:1) was reﬂuxed in the

presence of 2 N NaOH for 3 h, then, the resulting solution

was cooled to room temperature and acidiﬁed to pH 4 with

37 % HCl. The precipitate formed was ﬁltered off, washed

with water and recrystallized from acetone to afford the

desired compound. Yield 45 %, mp 201–202 °C. IR (KBr,

All test microorganisms were obtained from the Hi-

fzissihha Institute of Reﬁk Saydam (Ankara, Turkey) and

were as follows: Escherichia coli (E. coli) ATCC 35218,

Yersinia pseudotuberculosis (Y. pseudotuberculosis)

ATCC 911, Pseudomonas aeruginosa (P. aeruginosa)

ATCC 43288, Enterococcus faecalis (E. faecalis) ATCC

29212, Staphylococcus aureus (S. aureus) ATCC 25923,

Bacillus cereus (B. cereus) 709 Roma, Mycobacterium

smegmatis (M. smegmatis) ATCC 607, Candida albicans

(C. albicans) ATCC 60193 and Saccharomyces cerevisiae

(S. cerevisiae) RSKK 251. All the newly synthesized

compounds were weighed and dissolved in hexane to

prepare extract stock solution of 20.000 microgram/milli-

litre (lg/mL).

The antimicrobial effects of the substances were tested

quantitatively in respective broth media using double

microdilution and the MIC values (lg/mL) were deter-

mined (Willanova, 1993). The antibacterial and antifungal

assays were performed in Mueller–Hinton broth (Difco,

Detroit, MI) at pH 7.3 and buffered yeast nitrogen base

(Difco, Detroit, MI) at pH 7.0, respectively. The microdi-

lution test plates were incubated for 18–24 h at 35 °C.

Brain heart infusion broth (BHI; Difco, Detriot, MI) was

used for Ms, and incubated for 48–72 h at 35 °C (Woods

et al., 2003). Ampicillin (10 lg) and ﬂuconazole (5 lg)

were used as standard antibacterial and antifungal drugs,

respectively. DMSO with dilution of 1:10 was used as

solvent control. The results are presented in Table 1.

1

t, cm^-1): 2812 (SH), 1689 (C=O), 1604 (C=N). H NMR

(DMSO-d₆, d ppm): 2.22 (s, 3H, CH₃), 4.92 (s, 2H, CH₂),

7.30 (s, 1H, ArH), 7.41 (brs, 4H, ArH), 7.76 (s, 2H, ArH),

8.72 (s, 2H, ArH), 9.40 (s, 1H, N=CH), 13.55 (s, 1H, SH,

D₂O exch.). ¹³C NMR (DMSO-d₆, d ppm): 11.42 (CH₃),

78.87 (CH₂), 122.02 (2CH), 128.16 (2CH), 129.81 (CH),

129.96 (2CH), 133.53 (C), 141.04 (triazole C-3), 143.71

(CH), 144.68 (triazole C-5), 147.86 (C), 149.00 (C=O),

151.08 (2CH), 151.64 (N=CH), 169.29 (C=S). EI MS m/

z (%): 415.33 (27), 393.30 ([M ? 1]^?, 90), 190.89 (27).

Elemental analysis for C₁₈H₁₆N₈OS, Calculated (%), C:

55.09; H: 4.11; N: 28.55.

Found (%), C: 55.22; H: 4.08; N: 28.38.

N⁰-[5-(4-Chlorophenyl)-3-phenyl-1,3-thiazol-2(3H)-ylidene]-

2-(3-methyl-5-oxo-4-[(pyridin-4-ylmethylene)amino]-4,5-dihy-

dro-1H-1,2,4-triazol-1-yl)acetohydrazide (24) 4-Chlor-

ophenacyl bromide (10 mmol) was added to the solution of

compound 22 in absolute ethanol, and the reaction mixture

was reﬂuxed in the presence of dried sodium acetate

123

4944

Med Chem Res (2013) 22:4930–4945

Acknowledgments This Project was supported by Karadeniz

Technical University, BAP, Turkey (Ref. No. 8623) and is gratefully

acknowledged.

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Article Doi

Preparation and antimicrobial activity evaluation of some new bi- and triheterocyclic azoles

DOI: 10.1007/s00044-013-0498-3

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