Synthesis of novel symmetrical 1,4-disubstituted 1,2,3-bistriazole derivatives via 'click chemistry' and their biological evaluation

Article abstract of DOI:10.3390/molecules21050659

A series of symmetric bis-1,2,3-triazole compounds 2-5(a-f) were synthesized as potential antioxidant agents via click chemistry. Their structures were confirmed by ¹H-NMR and ¹³C-NMR. All of the synthesized compounds were subjected

Full text of DOI:10.3390/molecules21050659

molecules
Article
Synthesis of Novel Symmetrical 1,4-Disubstituted
1,2,3-Bistriazole Derivatives via ‘Click Chemistry’ and
Their Biological Evaluation
Esra Düg˘dü 1,*, Dilek Ünlüer 1, Fatih Çelik 1, Kemal Sancak 1, S¸engül Alpay Karaog˘lu 2 and
Arzu Özel 3
1
Department of Chemistry, Karadeniz Technical University, Trabzon 61080, Turkey;
dunluer@yahoo.com (D.Ü.); fatih.celik@ktu.edu.tr (F.Ç.); ksancak@ktu.edu.tr (K.S.)
Department of Biology, Recep Tayyip Erdog˘an University, Rize 53100, Turkey;
2
sengul.karaoglu@erdogan.edu.tr
Faculty of Pharmacy, Karadeniz Technical University, Trabzon 61080, Turkey; arzuozenozel@ktu.edu.tr
3
*
Correspondence: esradugdu@gmail.com; Tel.: +90-462-377-1781
Academic Editor: Derek McPhee
Received: 3 March 2016; Accepted: 11 May 2016; Published: 19 May 2016
Abstract: A series of symmetric bis-1,2,3-triazole compounds
2
–
5
(
a
–
f
) were synthesized as
1
potential antioxidant agents via click chemistry. Their structures were confirmed by H-NMR
and 13C-NMR. All of the synthesized compounds were subjected to antioxidant and antimicrobial
assays. The antioxidant activity of these compounds (AChE inhibition, DPPH and SOD activities) was
evaluated. Compound 2f was found to show the highest AChE inhibition activity of all compounds,
while compound 3b showed a strong inhibitory effect on DPPH radical and compound 2a was the
most effective of all compounds for SOD activity. All synthesized compounds were found to possess
moderate antibacterial activity against the bacteria E. coli and Y.pseudotuberculosis.
Keywords: 1,2,3-triazole; 1,3-dipolar cycloaddition; antioxidant activity; antimicrobial activity
1. Introduction
N-heterocyclic compounds, especially 1,2,3-triazoles, have received special attention because
of their widespread use in the synthetic and medicinal chemistry. 1,2,3-Triazoles are considered as
interesting heterocycles due to their important pharmacological activities such as antiprotozoal [
anticonvulsant, anti-HIV [ ], antimicrobial, antioxidant [ ], antifungal [ ], antimalarial [
anticancer [ ], antiinflammatory, and antitubercular agents [10
1
8
],
],
2
,3
4
5–7
9
,
11], etc. There are however very
few 1,2,3-triazole-containing molecules on the market or in the last stage of clinical trials. Potential
pharmaceuticals based on 1,2,3-triazoles include the anticancer compound carboxy amido triazole
(CAI), the β-lactam antibiotic tazobactum, the cephalosporin cefatrizine, and so on (Figure 1) [12].
Substituted 1,2,3-triazole derivatives have been considered as vital structural functionality units
commonly available as versatile building blocks in natural products, dyes, corrosion inhibitors, photo
stabilizers, photographic materials and agrochemicals [13,14].
The copper-catalyzed azide-alkyne cycloaddition reaction is known for its high fidelity in the
presence of many functional groups and under demanding reaction conditions. The experimental
simplicity and high selectivity of this process have been exploited in many applications in
synthetic and medicinal chemistry, bioconjugations, materials science and polymer chemistry [15].
The copper(I)-catalyzed reaction sequence which regiospecifically joins azides and terminal acetylenes
gives only 1,4-disubstituted 1,2,3-triazoles [16]. The process is experimentally simple and appears to
have enormous scope.
Molecules 2016, 21, 659; doi:10.3390/molecules21050659
www.mdpi.com/journal/molecules

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Here we report an efficient synthesis of novel bis-1,2,3-triazole derivatives
2
–5
(
a–
f) containing
alkyl chain bridges via copper-catalyzed click chemistry. In connection with our ongoing programme
on the synthesis of bistriazole compounds we were interested in exploring the above cycloaddition
reaction where some of the key building blocks contained substituted phenoxy groups. Moreover, we
evaluated antioxidant and antimicrobial activity of the products against various microorganisms as
1,2,3-triazole compounds are known to have significant biological activity.
Figure 1. Potential pharmaceuticals based on 1,2,3-triazoles.
2. Results and Discussion
The synthesis of the intermediate and target compounds was performed according to the
reactions outlined in Scheme 1. As shown, commercially available hydroxy acetophenones
or benzaldehydes were subjected to O-alkylation with propargyl bromide in the presence of
K2CO3 in DMF. The starting compounds
literature procedure [17]. Then compounds
2
–
2
5
–
were obtained following a previously reported
5 were reacted with the bisalkylazide derivatives
1,3-diazido-propane, 1,4-diazidobutane, 1,5-diazidopentane, 1,6-diazidohexane, 1,8-diazidooctane
and 1,10-diazidodecane ((-CH2-)n, n = 3, 4, 5, 6, 8, 10) under standard “click chemistry” conditions
using a copper sulfate pentahydrate/sodium ascorbate system as catalyst, also known as the Huisgen
1,3-dipolar cycloaddition reaction. The reaction conditions in this step are crucial. Because when
tert-butyl alcohol/water or ethanol/water solutions were used as solvent this reaction failed to afford
the target molecules under these conditions, it was tested with a (1:4) ratio acetone/water solvent
system whereby unlike in those solvent systems, the synthesis of the target molecules
was accomplished.
2–5(a–f))
The analytical and spectroscopic data of compounds
derived from the –CH2C CH groups at the expected chemical shift values. Moreover, compounds
gave a stable [M]+ ion peak. The 1H-NMR spectra of compounds
) displayed no signals
belonging to the –CH2C CH group; instead, new signals derived from the 1,2,3-triazole structure
2–5 confirmed this by the additional signals
”
2
–
5
2–5(a–f
”
appeared at 8.13–8.45 ppm (-trz CH) integrating for two protons. Furthermore, compounds
gave relatively stable [M]+ ion peaks.
2–5(a–f)
Scheme 1. Cont.

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Scheme 1. Synthetic pathway for the preparation of compounds 2–5(a–f).
´1
The IR spectra of compounds
2–5
(a–
f
) displayed a new sharp signal at 1600 cm corresponding
C=C absorptions, while the acetylene peak in
2
–
5
disappeared. Also different from compounds
2–5
the 1H-NMR spectra of the target compounds exhibited additional signals due to the 1,2,3-triazole
moiety which were observed at 8.13–8.45 ppm, the expected chemical shift values. Moreover, the
N–CH2 and –CH2 proton signals belonging to compounds 2–5(a–f) were observed in the 4.33–4.93 ppm
range. In the 13C-NMR spectra of the target compounds the acetylene carbon peaks observed in the
70–80 ppm range disappeared with the formation of 1,2,3-triazole rings, and quaternary carbon peaks
were observed in the range of 140–145 ppm. In addition, compounds
molecular ion peaks in the corresponding mass spectra.
2–5(a–f) gave relatively stable
The biological activity results of all the compounds were expressed as IC50 values and are
presented as mean S.D. of three independent experiments in Table 1. All of the compounds
˘
displayed promising AChE inhibitory activities, with IC50 values comparable to galantamine used as
the reference drug. As can be seen in Table 1, the IC50 values of all the compounds examined were in
the 50.80–88.60 µM range. The IC50 values of the compounds of series
inhibitory activities but all of the rest remained below 70 M. Compound 2f
displayed the highest inhibition activity of all compounds. The IC50 values of the compounds of
series 3a 3f were below 80 M. In this series compound 3b displayed much higher activity than
2,
2a–
2f indicated remarkable
µ
(
50.80 (˘1.01) µM
)
3
,
–
µ
the other compounds. Compound 4d showed important activity in the compound
compound 5e displayed promising inhibitory activity in the 5 series.
4 series, while
Some 1,2,3-triazole compounds are known to act either as inhibitors of free radical production or
as radical scavengers. Therefore, the potential antioxidant property of the new 1,2,3-trizole compounds
was evaluated by determining their DPPH and SOD radical scavenging ability. DPPH is a stable free
radical that accepts an electron or hydrogen radical to become a stable species [18]. Due to its odd
electron, DPPH gives a strong absorption band at 517 nm. Antioxidants are suitable reducing agents
and neutralize the free radicals by pairing the DPPH odd electron with a hydrogen atom, and the
DPPH solution turns yellow, observed as the decrease in absorbance at 517 nm [19].

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In our study, we evaluated the DPPH scavenging activity of compounds and a standard
antioxidant such as BHA as IC50 values (Table 1 and Figure 2). Compound 3b with an IC50 value
of 113.63
µg/mL showed a strong inhibitory effect on DPPH radical. All other compounds showed
moderate activities compared to BHA (IC50 98.56 µg/mL).
Table 1. IC50 values of the 1,2,3-triazole compounds 2–5(a–f) for AChE inhibition, DPPH and SOD activities.
Compound
AChE IC50 (µM)
DPPH IC50 (µg/mL)
SOD IC50 (µg/mL)
2a
2b
2c
2d
2e
2f
3a
3b
3c
3d
3e
3f
4a
4b
4c
4d
4e
4f
5a
5b
5c
5d
5e
64.65 (˘2.05)
52.29 (˘0.16)
67.03 (˘1.62)
62.41 (˘0.85)
66.38 (˘2.50)
50.80 (˘1.01)
63.28 (˘0.96)
56.98 (˘3.87)
75.70 (˘6.97)
75.74 (˘7.19)
56.99 (˘0.74)
78.60 (˘0.81)
62.82 (˘1.07)
74.13 (˘7.5)
83.37 (˘1.19)
58.49 (˘0.72)
63.39 (˘0.09)
62.52 (˘2.55)
74.69 (˘0.84)
61.85 (˘3.54)
69.41 (˘0.72)
70.31 (˘4.65)
61.81 (˘2.57)
15.09 (˘0.01)
-
155.49 (˘0.08)
158.72 (˘0.05)
175.65 (˘0.06)
152.84 (˘0.05)
222.16 (˘0.07)
167.51 (˘0.05)
141.57 (˘0.08)
113.63 (˘0.05)
188.45 (˘0.11)
149.21 (˘0.06)
252.68 (˘0.06)
207.57 (˘0.09)
192.02 (˘0.12)
125.05 (˘0.08)
227.38 (˘0.07)
204.31 (˘0.11)
192.04 (˘0.09)
210.33 (˘0.08)
150.03 (˘0.08)
154.51 (˘0.07)
192.46 (˘0.11)
191.39 (˘0.08)
221.57 (˘0.06)
-
45.12 (˘0.04)
107.54 (˘0.07)
147.36 (˘0.05)
154.79 (˘0.06)
131.43 (˘0.06)
88.15 (˘0.06)
120.53 (˘0.04)
51.37 (˘0.07)
284.10 (˘0.07)
128.24 (˘0.10)
52.89 (˘0.06)
98.35 (˘0.06)
55.67 (˘0.08)
121.74 (˘0.08)
60.32 (˘0.07)
82.77 (˘0.11)
88.86 (˘0.09)
93.47 (˘0.09)
126.2 (˘0.07)
109.17 (˘0.10)
145.68 (˘0.11)
157.14 (˘0.07)
188.84 (˘0.08)
-
Galantamine
BHA
98.56 (˘0.08)
-
300
250
200
150
100
50
DPPH
SOD
0
2a 2b 2c 2d 2e 2f 3a 3b 3c 3d 3e 3f 4a 4b 4c 4d 4e 4f 5a 5b 5c 5d 5e
Figure 2. Graphical representation of the antioxidant activity of the tested compounds.
The SOD activity of the compounds was investigated by an NBT assay and the results are shown in
Table 1 and Figure 2. Compound 2a (IC50 = 45.12 µg/mL) was the most effective of all compounds for

Molecules 2016, 21, 659
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´‚
scavenging superoxide radicals (O2 ). Compounds 3b (IC50 = 51.37 µg/mL), 3e (IC50 = 52.89 µg/mL)
and 4a (IC50 = 55.67 µg/mL) also exhibited strong superoxide radical scavenging activity.
All the synthesized compounds were found to possess antibacterial activity against the bacteria
E. coli and Y. pseudotuberculosis, which are Gram-negative enteric (intestinal origin) species. In some
molecules, antimycotic effects were observed at very low levels against S. cerevisiae and C. albicans
yeast. None of the synthesized molecules were observed to have antibacterial activity against Gram
negative bacteria (P. aeruginosa), other Gram positive bacteria (B. cereus, S. aureus and E. faecalis) or
antitubercular activity against M. smegmatis.
3. Experimental Section
3.1. General Information
1
Melting points were measured on an Electrothermal apparatus and are uncorrected. H-NMR and
13C-NMR spectra were recorded on an FT-400 NMR spectrophotometer (Agilent, Santa Clara, CA, USA)
in DMSO-d6. IR spectra were recorded on a Spectrum one FT-IR spectrometer (Perkin-Elmer, Waltham,
MA, USA) in KBr pellets. The MS spectra were measured with a Micromass Quattro LC/ULTIMA
LC-MS/MS spectrometer (Waters, Milford, MA, USA) with EtOH as solvent. The experiment was
performed in the positive ion mode. Elemental analyses were performed on a Hewlett-Packard
185 CHN analyzer (Avondale, PA, USA). All the chemicals were obtained from Fluka Chemie AG
(Buchs, Switzerland) and Sigma-Aldrich (St. Louis, MO, USA). Electric eel acetyl-cholinesterase
enzyme (AchE, Type-VI-S; EC 3.1.1.7), acetylthiocholine iodide (ATCI), 5,5-dithiobis(2-nitrobenzoic)
acid (DTNB), galantamine and 2,2-diphenyl-1-picrylhydrazyl (DPPH), methanol, and Trisma-base were
purchased from Sigma-Aldrich and used for the measurement of the acetyl-cholinesterase inhibition
and antioxidant activities.
3.2. Synthesis of Compounds 2–5
Acetylene derivatives 1 (0.010 mol) and potassium carbonate (0.015 mol) were refluxed in DMF
for 1 h. The reaction mixture was cooled to room temperature and propargyl bromide (0.01 mol) was
added and the mixture stirred at room temperature for 24 h. The reaction mixture was poured into
200 mL of ice-cold water. The solid obtained was washed with water and recrystallized from ethanol
to afford the desired title compounds 2–5 [17].
3.3. General Synthesis Method for the 2–5(a–f)
Bisalkylazide derivatives (-CH2-)n (n = 3,4,5,6,8,10) (0.01 mol) and compounds 2–5 (0.02 mol)
were stirred in (1:4) water/acetone solution at room temperature for one hour. Then copper sulfate
pentahydrate (1/20) and sodium ascorbate (1/10) were added and the reaction mixture was refluxed
for 24 h. At the end of the reaction the flask contents were poured into ice water and a solid was
obtained, which was filtered, washed with water and recrystallized from DMF-ethanol to afford the
target compounds 2–5(a–f).
1
1,1 -((((Propane-1,3-diylbis(1H-1,2,3-triazole-1,4-diyl))bis(methylene))bis(oxy))bis(4,1-phenylene))bis(ethan-1-
˝
one) (2a). Yield: 80.02%; m.p. 181–182 C; IR (
ppm): 2.46 (m, 2H, -CH2-), 2.51 (s, 6H, -CH3), 4.43 (t, 4H, N-CH2), 5.25 (s, 2H, O-CH2), 7.13–7.15 (d,
4H, Arom. H), 7.92–7.94 (d, 4H, Arom. H), 8.30 (s, 2H, Arom. -1,2,3-trz. H); 13C-NMR (
ppm): 26.85
ν
, cm´1): 1674 (C=O), 1605 (C=C), 1255 (C-O); 1H-NMR
(δ
δ
(-CH3), 30.61 (-CH2-), 47.25 (N-CH2), 61.85 (O-CH2), Arom. C [115.02 (CH), 125.30 (trz. CH), 130.64
(C), 130.91 (CH), 142.76 (trz. C-N), 162.31 (C)], 196.76 (C=O); Anal. Calcd (%) for C25H26N6O4 (474.20):
C, 63.28; H, 5.52; N, 17.71; found: C, 63.22; H, 5.56; N, 17.73; MS (ESI): m/z (%) 475.55 [M + 1]+.
1,11-((((Butane-1,4-diylbis(1H-1,2,3-triaz˝ole-1,4-diyl))bis(methylene))bis(oxy))bis(4,1-phenylene))bis(ethan-1-
one) (2b). Yield: 75.02%; m.p. 183–184 C; IR (ν
, cm´1): 1677 (C=O), 1600 (C=C),1248 (C-O); 1H-NMR
(δ ppm): 1.78 (bs, 4H, -CH2-), 2.49 (s, 6H, -CH3), 4.39 (bs, 4H, N-CH2), 5.22 (s, 4H, O-CH2), 7.10–7.13 (d,

Molecules 2016, 21, 659
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4H, Arom. H), 7.89–7.92 (d, 4H, Arom. H), 8.23 (s, 2H, Arom. -1,2,3-trz. H); 13C-NMR (
δ
ppm): 26.07
(-CH3), 27.15 (-CH2-), 49.10 (N-CH2), 63.92 (O-CH2), Arom. C [114.94 (CH), 128.54 (trz. CH), 130.51
(C), 130.91 (CH), 142.58 (trz. C-N), 162.38 (C)], 196.76 (C=O); Anal. Calcd (%) for C26H28N6O4 (488.22):
C, 63.92; H, 5.78; N, 17.20; found: C, 63.91; H, 5.75; N, 17.21; MS (ESI): m/z (%) 527.23 [M + 1]+.
1
1,1 -((((Pentane-1,5-diylbis(1H-1,2,3-triazole-1,4-diyl))bis(methylene))bis(oxy))bis(4,1-phenylene))bis(ethan-1-
˝
one) (2c). Yield: 75.02%; m.p. 147–148 C; IR (
ppm): 1.20–1.30 (m, 2H, -CH2-), 1.80–1.85 (m, 4H, -CH2-), 2.48 (s, 6H, -CH3), 4.33 (bs, 4H,
N-CH2), 5.21 (s, 4H, O-CH2), 7.10–7.13 (d, 4H, Arom. H), 7.89–7.92 (d, 4H, Arom. H), 8.22 (s, 2H,
Arom. -1,2,3-trz. H); 13C-NMR (
ppm) : 23.20 (-CH2-), 26.83 (-CH3), 29.43 (-CH2-), 49.59 (N-CH2),
ν
, cm´1): 1673 (C=O), 1604 (C=C), 1246 (C-O); 1H-NMR
(δ
δ
61.84 (O-CH2), Arom. C [114.96 (CH), 125.10(trz.CH), 130.56 (C), 130.89 (CH), 141.35 (trz. C-N), 162.28
(C)], 196.74 (C=O); Anal. Calcd (%) for C27H30N6O4 (502.23): C, 64.53; H, 6.02; N, 16.72; found: C,
64.50; H, 6.01; N, 16.75; MS (ESI): m/z (%) 503.33 [M + 1]+.
1
1,1 -((((Hexane-1,6-diylbis(1H-1,2,3-triazole-1,4-diyl))bis(methylene))bis(oxy))bis(4,1-phenylene))bis(ethan-1-
˝
one) (2d). Yield: 78.15%; m.p. 166–167 C; IR (
ppm): 1.15–1.25 (m, 4H, -CH2-), 1.71–1.82 (m, 4H, -CH2-), 2.47 (s, 6H, -CH3), 4.30 (bs, 4H,
N-CH2), 5.20 (s, 4H, O-CH2), 7.10–7.14 (d, 4H, Arom. H), 7.87–7.92 (d, 4H, Arom. H), 8.21 (s, 2H,
Arom. -1,2,3-trz. H); 13C-NMR (
ppm): 25.63 (-CH2-) 26.82 (-CH3), 29.87 (-CH2-), 49.71 (N-CH2),
ν
, cm´1): 1677 (C=O), 1600 (C=C), 1246 (C-O); 1H-NMR
(δ
δ
61.84 (O-CH2), Arom. C [114.98 (CH), 128.45 (trz. CH), 125.48 (C), 130.88 (CH), 142.55 (trz. C-N),
165.40 (C)], 196.95 (C=O); Anal. Calcd (%) for C28H32N6O4 (516.25): C, 65.10; H, 6.24; N, 16.27; found:
C, 65.12; H, 6.25; N, 16.25; MS (ESI): m/z (%) 517.47 [M + 1]+.
1,11-((((Octane-1,8-diylbis(1H-1,2,3-triazole-1,4-diyl))bis(methylene))bis(oxy))bis(4,1-phenylene))bis(ethan-1-
˝
one) (2e). Yield: 76.15%; m.p. 169–170 C; IR (
1H-NMR (
ppm) : 1.16–1.24 (m, 8H, -CH2-), 1.72–1.81 (m, 4H, -CH2-), 2.48 (s, 6H, -CH3), 4.33 (bs,
4H, N-CH2), 5.21 (s, 4H, O-CH2), 7.10–7.12 (d, 4H, Arom. H), 7.89–7.91 (d, 4H, Arom. H), 8.22 (s, 2H,
Arom. -1,2,3-trz. H); 13C-NMR (
ppm): 26.13 (-CH2-), 26.83 (-CH2-), 28.59 (-CH3), 30.04 (-CH2-), 49.81
ν
, cm´1): 1678 (C=O), 1601 (C=C), 1252 (C-O);
δ
δ
(N-CH2), 61.83 (O-CH2), Arom. C [114.99 (CH), 125.01 (trz. CH), 130.55 (C), 130.87 (CH), 142.38 (trz.
C-N), 162.28 (C)], 196.72 (C=O); Anal. Calcd (%) for C30H36N6O4 (544.28): C, 66.16; H, 6.66; N, 15.43;
found: C, 66.18; H, 6.64; N, 15.44; MS (ESI): m/z (%) 545.14 [M + 1]+.
1
1,1 -((((Decane-1,10-diylbis(1H-1,2,3-triazole-1,4-diyl))bis(methylene))bis(oxy))bis(4,1-phenylene))bis-(ethan-1-
˝
one) (2f). Yield: 74.15%; m.p. 165–166 C; IR (ν
, cm´1): 1677 (C=O), 1603 (C=C), 1251 (C-O); 1H-NMR
(δ ppm): 1.21–1.22 (m, 12H, -CH2-), 1.81 (m, 4H, -CH2-), 2.51 (s, 6H, -CH3), 4.35 (bs, 4H, N-CH2), 5.25
(s, 4H, O-CH2), 7.12–7.14 (d, 4H, Arom. H), 7.91–7.93 (d, 4H, Arom. H), 8.20 (s, 2H, Arom. -1,2,3-trz.
H); 13C-NMR (
δ ppm): 24.48 (-CH2-), 25.26 (-CH2-), 27.20 (-CH2-), 27.92 (-CH3), 30.78 (-CH2-), 50.42
(N-CH2), 62.25 (O-CH2), Arom. C [115.67 (CH), 128.42 (trz. CH), 130.30 (C), 130.69 (CH), 142.67 (trz.
C-N), 162.54 (C)], 197.65 (C=O); Anal. Calcd (%) for C32H40N6O4 (572.31): C, 67.11; H, 7.04; N, 14.67;
found: C, 67.13; H, 7.06; N, 14.64; MS (ESI): m/z (%) 595.35 [M + Na]+.
1-(4-((1-(3-(4-((4-Acetyl-2-methoxyphenoxy)methyl)-1H-1,2,3-triazol-1-yl)propyl)-1H-1,2,3-triazol-4-yl)-
methoxy)-2-methoxyphenyl)ethan-1-one (3a). Yield: 78.15%; m.p. 157–159 ˝C; IR ( , cm´1): 1674 (C=O),
ν
1587 (C=C), 1267 (C-O); 1H-NMR (
4.42 (t, 4H, N-CH2), 5.23 (s, 4H, O-CH2), 7.26–7.29 (d, 2H, Arom. H), 7.44 (s, 2H, Arom. H), 7.61–7.63
(d, 2H, Arom. H), 8.30 (s, 2H, Arom. -1,2,3-trz. CH); 13C-NMR (
ppm): 26.79 (-CH3), 30.64 (-CH2-),
δ ppm): 2.35–2.45 (m, 8H,(-CH2 and -CH3)), 3.79 (s, 6H, -OCH3),
δ
47.26 (N-CH2), 55.94 (-OCH3), 62.17 (O-CH2), Arom. C [110.93 (CH), 112.81 (CH), 123.34 (CH), 125.45
(trz. CH), 130.73 (C) ,142.71 (trz. C-N), 149.19 (C), 152.16 (C)], 196.85 (C=O); Anal. Calcd (%) for
C27H30N6O6 (534.22): C, 60.66; H, 5.66; N, 15.72; found: C, 60.61; H, 5.63; N, 15.70; MS (ESI): m/z (%)
557.35 [M + Na]+.
1-(4-((1-(4-(4-((4-Acetyl-2-methoxyphenoxy)methyl)-1H-1,2,3-triazol-1-yl)butyl)-1H-1,2,3-triazol-4-yl)-methoxy)-
˝
2-methoxyphenyl)ethan-1-one (3b). Yield: 76.14%; m.p. 158–159 C; IR (
ν
, cm´1): 1654 (C=O), 1590
(C=C), 1262 (C-O); 1H-NMR (
δ
ppm): 1.78–1.80 (m, 4H, -CH2-), 2.48 (s, 6H, -CH3), 3.77 (s, 6H, -OCH3),

Molecules 2016, 21, 659
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4.39 (t, 4H, N-CH2), 5.20 (s, 4H, O-CH2), 7.23–7.25 (d, 2H, Arom. H), 7.42 (s, 2H, Arom. H), 7.58–7.60
(d, 2H, Arom. H), 8.22 (s, 2H, Arom. -1,2,3-trz. CH); 13C-NMR (
ppm): 26.92 (-CH2-), 30.70 (-CH3),
δ
48.25 (N-CH2), 55.90 (-OCH3), 62.17 (O-CH2), Arom. C [110.16 (CH), 113.85 (CH), 123.44 (CH), 125.43
(trz. CH), 130.38 (C) ,142.42 (trz. C-N), 149.74 (C), 153.15 (C)], 196.65 (C=O); Anal. Calcd (%) for
C28H32N6O6 (548.24): C, 61.30; H, 5.88; N, 15.32; found: C, 61.32; H, 5.86; N, 15.34; MS (ESI): m/z (%)
571.38 [M + Na]+.
1-(4-((1-(5-(4-((4-Acetyl-2-methoxyphenoxy)methyl)-1H-1,2,3-triazol-1-yl)pentyl)-1H-1,2,3-triazol-4-yl)-methoxy)-
˝
2-methoxyphenyl)ethan-1-one (3c). Yield: 74.14%; m.p. 165–166 C; IR (
1261 (C-O); 1H-NMR (
ppm): 1.21 (m, 2H, -CH2-), 1.84 (m, 4H, -CH2-), 2.50 (s, 6H, -CH3), 3.77 (s,
6H, -OCH3), 4.35 (t, 4H, N-CH2), 5.20 (s, 4H, O-CH2), 7.22–7.24 (d, 2H, Arom. H), 7.42 (s, 2H, Arom.
H), 7.57–7.59 (d, 2H, Arom. H), 8.22 (s, 2H, Arom. -1,2,3-trz. CH); 13C-NMR (
ppm): 23.25 (-CH2-),
ν
, cm´1): 1668 (C=O), 1584 (C=C),
δ
δ
26.73 (-CH2-), 29.49 (-CH3), 49.59 (N-CH2), 55.84 (-OCH3), 62.14 (O-CH2), Arom. C [110.75 (CH),
112.61 (CH), 123.33 (CH), 125.21 (trz. CH), 130.62 (C) , 142.53 (trz. C-N), 149.11 (C), 152.12 (C)], 196.82
(C=O); Anal. Calcd (%) for C29H34N6O6 (562.25): C, 61.91; H, 6.09; N, 14.94; found; C, 61.92; H, 6.10; N,
14.95; MS (ESI): m/z (%) 585.35 [M + Na]+.
1-(4-((1-(6-(4-((4-Acetyl-2-methoxyphenoxy)methyl)-1H-1,2,3-triazol-1-yl)hexyl)-1H-1,2,3-triazol-4-yl)-methoxy)-
2-methoxyphenyl)ethan-1-onen (3d). Yield: 72.14%; m.p. 205–207 ˝C; IR (
ν
, cm´1): 1667 (C=O), 1582
1
(C=C), 1260 (C-O); H-NMR (
δ
ppm): 1.19–1.24 (m, 4H, -CH2-), 1.76–1.80 (m, 4H, -CH2-), 2.50 (s,
6H, -CH3), 3.76 (s, 6H, -OCH3), 4.32 (t, 4H, N-CH2), 5.20 (s, 4H, O-CH2), 7.23–7.25 (d, 2H, Arom. H),
7.42 (s, 2H, Arom. H), 7.58–7.60 (d, 2H, Arom. H), 8.23 (s, 2H, Arom. -1,2,3-trz. CH); 13C-NMR (
ppm)
: 25.66 (-CH2-), 26.76 (-CH2-), 29.91 (-CH3), 49.72 (N-CH2), 55.85 (-OCH3), 62.13 (O-CH2), Arom.
δ
δ
C [110.78 (CH), 112.65 (CH), 123.33 (CH), 125.19 (trz. CH), 130.62 (C) , 142.50 (trz. C-N), 149.12 (C),
152.12 (C)], 196.82 (C=O); Anal. Calcd (%) for C30H36N6O6 (576.27): C, 62.49; H, 6.29; N, 14.57; found:
C, 62.48; H, 6.30; N, 14.59; MS (ESI): m/z (%) 599.38 [M + Na]+.
1-(4-((1-(8-(4-((4-Acetyl-2-methoxyphenoxy)methyl)-1H-1,2,3-triazol-1-yl)octyl)-1H-1,2,3-triazol-4-yl)methoxy)-
˝
2-methoxyphenyl)ethan-1-one (3e). Yield: 75.14%; m.p. 172–174 C; IR (
1266 (C-O); 1H-NMR (
ppm): 1.18–1.22 (m, 8H, -CH2-), 1.75–1.80 (m, 4H, -CH2-), 2.50 (s, 6H, -CH3),
3.76 (s, 6H, -OCH3), 4.33 (t, 4H, N-CH2), 5.21 (s, 4H, O-CH2), 7.23–7.25 (d, 2H, Arom. H), 7.42 (s, 2H,
Arom. H), 7.58–7.60 (d, 2H, Arom. H), 8.23 (s, 2H, Arom. -1,2,3-trz. CH); 13C-NMR (
ppm) : 26.17
ν
, cm´1): 1669 (C=O), 1585 (C=C),
δ
δ
(-CH2-), 26.74 (-CH2-), 28.60 (-CH2-), 30.08 (-CH3), 49.80 (N-CH2), 55.84 (-OCH3), 62.13 (O-CH2), Arom.
C [110.78 (CH), 112.65 (CH), 123.31 (CH), 125.18 (trz. CH), 130.62 (C), 142.49 (trz. C-N), 149.13 (C),
152.12 (C)], 196.79 (C=O); Anal. Calcd (%) for C32H40N6O6 (604.30): C, 63.56; H, 6.67; N, 13.90; found:
C, 63.58; H, 6.68; N, 13.92; MS (ESI): m/z (%) 605.31 [M + 1]+.
1-(4-((1-(10-(4-((4-Acetyl-2-methoxyphenoxy)methyl)-1H-1,2,3-triazol-1-yl)decyl)-1H-1,2,3-triazol-4-yl)-methoxy)-
˝
2-methoxyphenyl)ethan-1-one (3f). Yield: 73.35%; m.p. 120–122 C; IR (
1266 (C-O); 1H-NMR (
ppm) : 1.04–1.18 (m, 12H, -CH2-), 1.75–1.79 (m, 4H, -CH2-), 2.50 (s, 6H, -CH3),
3.76 (s, 6H, -OCH3), 4.33 (t, 4H, N-CH2), 5.20 (s, 4H, O-CH2), 7.23–7.25 (d, 2H, Arom. H), 7.42 (s, 2H,
Arom. H), 7.58–7.60 (d, 2H, Arom. H), 8.23 (s, 2H, Arom. -1,2,3-trz. CH); 13C-NMR (
ppm): 26.26
ν
, cm´1): 1670 (C=O), 1587 (C=C),
δ
δ
(-CH2-), 26.76 (-CH2-), 28.74 (-CH2-), 29.16 (-CH2-), 30.14 (-CH3), 49.83 (N-CH2), 55.86 (-OCH3), 62.12
(O-CH2), Arom. C [110.79 (CH), 112.67 (CH), 123.32 (CH), 125.19 (trz. CH), 130.62 (C), 142.50 (trz.
C-N), 149.13 (C), 152.12 (C)], 196.79 (C=O); Anal. Calcd (%) for C34H44N6O6 (632.33): C, 64.54; H, 7.01;
N, 13.28; found: C, 64.56; H, 7.04; N, 13.29; MS (ESI): m/z (%) 655.24 [M + Na]+.
4,41-(((Propane-1,3-diylbi˝s(1H-1,2,3-triazole-1,4-diyl))bis(methylene))bis(oxy))dibenzaldehyde (4a). Yield:
1
70.18%; m.p. 115–116 C; IR (
ν
, cm´1): 1688 (C=O), 1598 (C=C), 1253 (C-O); H-NMR (
δ
ppm):
2.43–2.45 (m, 2H, -CH2-), 4.43 (t, 4H, N-CH2), 5.27 (s, 4H, O-CH2), 7.21–7.23 (d, 4H, Arom. H), 7.84–7.86
(d, 4H, Arom. H), 8.30 (s, 2H, Arom. -1,2,3-trz. H), 9.85 (s, 2H, aldehyde-CH); 13C-NMR (
ppm): 30.61
(-CH2-), 47.26 (N-CH2), 61.95 (O-CH2), Arom. C [115.62 (CH), 125.43 (trz. CH), 130.31 (C), 132.22 (CH),
δ

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143.53 (trz. C-N), 163.38 (C)], 191.74 (aldehyde-CH); Anal. Calcd (%) for C23H22N6O4 (446.17): C, 61.88;
H, 4.97; N, 18.82; found: C, 61.86; H, 4.98; N, 18.84; MS (ESI): m/z (%) 469.29 [M + Na]+.
4,41-(((Butane-1,4-diylbis˝(1H-1,2,3-triazole-1,4-diyl))bis(methylene))bis(oxy))dibenzaldehyde (4b). Yield:
1
73.53%; m.p. 154–155 C; IR (
ν
, cm´1): 1682 (C=O), 1601 (C=C), 1245 (C-O); H-NMR (
δ
ppm):
1.79 (bs, 4H, -CH2-), 4.40 (t, 4H, N-CH2), 5.25 (s, 4H, O-CH2), 7.20 (s, 4H, Arom. H), 7.84 (s, 4H, Arom.
H), 8.24 (s, 2H, Arom. -1,2,3-trz. H), 9.85 (s, 2H, aldehyde-CH); 13C-NMR (
ppm): 27.42 (-CH2-), 49.20
δ
(N-CH2), 61.95 (O-CH2), Arom. C [115.64 (CH), 125.21 (trz. CH), 130.31 (C), 132.22 (CH), 142.49 (trz.
C-N), 163.39 (C)], 191.77 (aldehyde-CH); Anal. Calcd (%) for C24H24N6O4 (460.19): C, 62.60; H, 5.25; N,
18.25; found: C, 62.62; H, 5.26; N, 18.27; MS (ESI): m/z (%) 483.28 [M + Na]+.
4,41-(((Pentane-1,5-diylbis(1H-1,2,3-triazole-1,4-diyl))bis(methylene))bis(oxy))dibenzaldehyde (4c). Yield:
˝
76.73%; m.p. 98–99 C; IR (ν δ ppm) : 1.19–1.21
, cm´1): 1693 (C=O), 1600 (C=C), 1243 (C-O); 1H-NMR (
(m, 2H, -CH2-), 1.81–1.84 (m, 4H, -CH2-), 4.34 (t, 4H, N-CH2), 5.25 (s, 4H, O-CH2), 7.20–7.22 (d, 4H,
Arom. H), 7.84–7.86 (d, 4H, Arom. H), 8.24 (s, 2H, Arom. -1,2,3-trz. H), 9.85 (s, 2H, aldehyde-CH);
13C-NMR (
δ ppm): 23.21 (-CH2-), 29.45 (-CH2-), 49.59 (N-CH2), 61.97 (O-CH2), Arom. C [115.64 (CH),
125.12 (trz. CH), 130.30 (C), 132.22 (CH), 142.41 (trz. C-N), 163.39 (C)], 191.76 (aldehyde-CH); Anal.
Calcd (%) for C25H26N6O4 (474.20): C, 63.28; H, 5.52; N, 17.71; found: C, 63.26; H, 5.53; N, 17.73; MS
(ESI): m/z (%) 475.42 [M + 1]+.
4,41-(((Hexane-1,6-diylbis(1H-1,2,3-triazole-1,4-diyl))bis(methylene))bis(oxy))dibenzaldehyde (4d). Yield:
˝
1
76.73%; m.p. 100–101 C; IR (ν δ ppm) :
, cm´1): 1683 (C=O), 1608 (C=C), 1242 (C-O); H-NMR (
1.21 (bs, 4H, -CH2-), 1.76 (bs, 4H, -CH2-), 4.32 (t, 4H, N-CH2), 5.26 (s, 4H, O-CH2), 7.19–7.21 (d, 4H,
Arom. H), 7.83–7.85 (d, 4H, Arom. H), 8.26 (s, 2H, Arom. -1,2,3-trz. H), 9.84 (s, 2H, aldehyde-CH);
13C-NMR (
δ ppm) : 25.63 (-CH2-), 29.87 (-CH2-), 49.76 (N-CH2), 62.00 (O-CH2), Arom. C [115.62 (CH),
130.29 (trz. CH), 132.18 (C) , 132.23 (CH), 142.50 (trz. C-N), 163.38 (C)], 191.71 (aldehyde-CH); Anal.
Calcd (%) for C26H28N6O4 (488.22): C, 63.92; H, 5.78; N, 17.20; found: C, 63.94; H, 5.77; N, 17.22; MS
(ESI): m/z (%) 489.25 [M + 1]+.
4,41-(((Octane-1,8-di˝ylbis(1H-1,2,3-triazole-1,4-diyl))bis(methylene))bis(oxy))dibenzaldehyde (4e). Yield:
76.73%; m.p. 94–95 C; IR (ν δ ppm) : 1.17 (bs,
, cm´1): 1690 (C=O), 1605 (C=C), 1246 (C-O); 1H-NMR (
8H, -CH2-), 1.76 (bs, 4H, -CH2-), 4.33 (t, 4H, N-CH2), 5.26 (s, 4H, O-CH2), 7.19–7.21(d, 4H, Arom. H),
7.83–7.85 (d, 4H, Arom. H), 8.25 (s, 2H, Arom. -1,2,3-trz. H), 9.85 (s, 2H, aldehyde-CH); 13C-NMR
(δ ppm): 26.15 (-CH2-), 28.59 (-CH2-), 30.06 (-CH2-), 49.85 (N-CH2), 61.98 (O-CH2), Arom. C [115.62
(CH), 125.11 (trz. CH), 130.29 (C), 132.19 (CH), 142.47 (trz. C-N), 163.39 (C)], 191.66 (aldehyde-CH);
Anal.Calcd (%) for C28H32N6O4 (516.25): C, 65.10; H, 6.24; N, 16.27; found: C, 65.12; H, 6.25; N, 16.28;
MS (ESI): m/z (%) 517.14 [M + 1]+.
4,41-(((Decane-1,10-diylbis(1H-1,2,3-triazole-1,4-diyl))bis(methylene))bis(oxy))dibenzaldehyde (4f). Yield:
74.16%; m.p. 72–73 ˝C; IR ( , cm´1): 1688 (C=O), 1604 (C=C), 1250 (C-O); 1H-NMR (
ν δ ppm): 1.36 (bs,
6H, -CH2-), 1.95 (bs, 4H, -CH2-), 4.51 (t, 4H, N-CH2), 5.43 (s, 4H, O-CH2), 7.38–7.40 (d, 4H, Arom. H),
8.02–8.04 (d, 4H, Arom. H), 8.43 (s, 2H, Arom. -1,2,3-trz. H), 10.03 (s, 2H, aldehyde-CH); 13C NMR
(δ ppm): 26.22 (-CH2-), 28.72 (-CH2-), 29.14 (-CH2-), 30.09 (-CH2-), 49.85 (N-CH2), 61.97 (O-CH2),
Arom. C [115.65 (CH), 125.11 (trz. CH), 130.28 (C), 132.19 (CH), 142.55 (trz. C-N), 163.39 (C)], 191.71
(aldehyde-CH); Anal. Calcd (%) for C30H36N6O4 (544.28): C, 66.16; H, 6.66; N, 15.43; found: C, 66.18;
H, 6.68; N, 15.44; MS (ESI): m/z (%) 545.26 [M + 1]+.
4-((1-(3-(4-((4-Formyl-2-methoxyphenoxy)methyl)-1H-1,2,3-triazol-1-yl)propyl)-1H-1,2,3-triazol-4-yl)-methoxy)-
2-methoxybenzaldehyde (5a). Yield: 82.69%; m.p. 90–92 ˝C; IR ( , cm´1): 1676 (C=O), 1588 (C=C), 1261
ν
(C-O); 1H-NMR (
O-CH2), 7.36 (s, 2H, Arom. H), 7.37–7.39 (d, 2H, Arom. H), 7.52–7.54 (d, 2H, Arom. H), 8.29 (s, 2H,
Arom. -1,2,3-trz. H), 9.82 (s, 2H, aldehyde-CH); 13C-NMR (
ppm): 30.63 (-CH2-), 47.25 (N-CH2), 55.90
(-OCH3), 62.19 (O-CH2), Arom. C [110.12 (CH), 113.04 (CH), 125.56 (trz. CH), 126.28 (CH), 130.37
δ ppm): 2.42–2.44 (m, 2H, -CH2-), 3.78 (s, 6H, -OCH3), 4.43 (t, 4H, N-CH2), 5.25 (s, 4H,
δ

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(C), 142.50 (C), 149.73 (trz. C-N), 153.25 (C)], 191.86 (aldehyde-CH); Anal. Calcd (%) for C25H26N6O6
(506.19): C, 59.28; H, 5.17; N, 16.59; found: C, 59.27; H, 5.18; N, 16.57; MS (ESI): m/z (%) 507.25 [M + 1]+
.
4-((1-(4-(4-((4-Formyl-2-methoxyphenoxy)methyl)-1H-1,2,3-triazol-1-yl)butyl)-1H-1,2,3-triazol-4-yl)-methoxy)-
˝
2-methoxybenzaldehyde (5b). Yield: 79.69%; m.p. 96–97 C; IR (
1263 (C-O); 1H-NMR (
ppm) : 1.80 (bs, 4H, -CH2-), 3.78 (s, 6H, -OCH3), 4.40 (t, 4H, N-CH2), 5.24
(s, 4H, O-CH2), 7.37 (s, 2H, Arom. H), 7.51 (s, 2H, Arom. H), 7.53 (s, 2H, Arom. H), 8.24 (s, 2H,
Arom. -1,2,3-trz. H), 9.82 (s, 2H, aldehyde-CH); 13C-NMR (
ppm): 27.29 (-CH2-), 49.20 (N-CH2), 55.90
ν
, cm´1): 1665 (C=O), 1585 (C=C),
δ
δ
(-OCH3), 62.22 (O-CH2), Arom. C [110.15 (CH), 113.05 (CH), 125.38 (trz. CH), 126.24 (CH), 130.38
(C), 142.42 (C), 149.74 (trz. C-N), 153.26 (C)], 191.83 (aldehyde-CH); Anal. Calcd (%) for C26H28N6O6
(520.21): C, 59.99; H, 5.42; N, 16.14; found: C, 59.98; H, 5.44; N, 16.15; MS (ESI): m/z (%) 521.23 [M + 1]+.
4-((1-(5-(4-((4-Formyl-2-methoxyphenoxy)methyl)-1H-1,2,3-triazol-1-yl)pentyl)-1H-1,2,3-triazol-4-yl)-methoxy)-
˝
2-methoxybenzaldehyde (5c). Yield: 88.60%; m.p. 141–142 C; IR (
(C-O); 1H-NMR (
ppm): 1.21 (m, 2H, -CH2-), 1.82–1.84 (m, 4H, -CH2-), 3.78 (s, 6H, -OCH3), 4.34 (t, 4H,
N-CH2), 5.24 (s, 4H, O-CH2), 7.34 (s, 2H, Arom. H), 7.35–7.39 (d, 2H, Arom. H), 7.51–7.54 (d, 2H, Arom.
H), 8.23 (s, 2H, Arom. -1,2,3-trz. H), 9.82 (s, 2H, aldehyde-CH); 13C-NMR (
ppm): 23.25 (-CH2-), 29.48
ν
, cm´1): 1675 (C=O), 1586 (C=C), 1261
δ
δ
(-CH2-), 49.60 (N-CH2), 55.91 (-OCH3), 62.24 (O-CH2), Arom. C [110.10 (CH), 113.01 (CH), 125.30 (trz.
CH), 126.26 (CH), 130.36 (C), 142.34 (C), 149.73 (trz. C-N), 153.27 (C)], 191.82 (aldehyde-CH); Anal.
Calcd (%) for C27H30N6O6 (534.22): C, 60.66; H, 5.66; N, 15.72; found: C, 60.68; H, 5.67; N, 15.73; MS
(ESI): m/z (%) 535.36 [M + 1]+.
4-((1-(6-(4-((4-Formyl-2-methoxyphenoxy)methyl)-1H-1,2,3-triazol-1-yl)hexyl)-1H-1,2,3-triazol-4-yl)-methoxy)-
2-methoxybenzaldehyde (5d). Yield: 68.60%, m.p. 151–152 ˝C. IR ( , cm´1): 1681 (C=O), 1587 (C=C),
ν
1262 (C-O); 1H-NMR (
4H, N-CH2), 5.23 (s, 4H, O-CH2), 7.33–7.35 (d, 2H, Arom. H), 7.36–7.38 (s, 2H, Arom. H), 7.52–7.54
(s, 2H, Arom. H), 8.24 (s, 2H, Arom. -1,2,3-trz. H), 9.82 (s, 2H, aldehyde-CH); 13C-NMR (
ppm):
δ ppm): 1.23 (bs, 4H, -CH2-), 1.77 (bs, 4H, -CH2-), 3.77 (s, 6H, -OCH3), 4.33 (t,
δ
25.65 (-CH2-), 29.90 (-CH2-), 49.73 (N-CH2), 55.90 (-OCH3), 62.23 (O-CH2), Arom. C [110.12 (CH),
113.04 (CH), 125.33 (trz. CH), 126.26 (CH), 130.35 (C), 142.35 (C), 149.73 (trz. C-N), 153.26 (C)], 191.84
(aldehyde-CH); Anal. Calcd (%) for C28H32N6O6 (548.24): C, 61.30; H, 5.88; N, 15.32; found: C, 61.32;
H, 5.89; N, 15.34; MS (ESI): m/z (%) 549.42 [M + 1]+.
4-((1-(8-(4-((4-Formyl-2-methoxyphenoxy)methyl)-1H-1,2,3-triazol-1-yl)octyl)-1H-1,2,3-triazol-4-yl)-methoxy)-
2-methoxybenzaldehyde (5e). Yield: 78.60%; m.p. 144–145 ˝C; IR ( , cm´1): 1690 (C=O), 1588 (C=C),
ν
1262 (C-O); 1H-MR (
(t, 4H, N-CH2), 5.24 (s, 4H, O-CH2), 7.34 (s, 2H, Arom. H), 7.36–7.38 (d, 2H, Arom. H), 7.51–7.52 (d,
2H, Arom. H), 8.24 (s, 2H, Arom. -1,2,3-trz. H), 9.82 (s, 2H, aldehyde-CH); 13C-NMR (
ppm): 26.17
δ ppm) : 1.05–1.19 (bs, 8H, -CH2-), 1.76 (m, 4H, -CH2-), 3.77 (s, 6H, -OCH3), 4.33
δ
(-CH2-), 28.60 (-CH2-), 30.08 (-CH2-), 49.83 (N-CH2), 55.87 (-OCH3), 62.23 (O-CH2), Arom. C [110.10
(CH), 113.00 (CH), 125.29 (trz. CH), 126.22 (CH), 130.36 (C), 142.38 (C), 149.73 (trz. C-N), 153.27 (C)],
191.77 (aldehyde-CH); Anal. Calcd (%) for C30H36N6O6 (576.27): C, 62.49; H, 6.29; N, 14.57; found: C,
62.48; H, 6.27; N, 14.56; MS (ESI): m/z (%) 577.36 [M + 1]+.
4-((1-(10-(4-((4-Formyl-2-methoxyphenoxy)methyl)-1H-1,2,3-triazol-1-yl)decyl)-1H-1,2,3-triazol-4-yl)-methoxy)-
2-methoxybenzaldehyde (5f). Yield: 69.63%; m.p. 84–85 ˝C; IR ( , cm´1): 1679 (C=O), 1586 (C=C), 1258
ν
(C-O); 1H-NMR (
N-CH2), 5.23 (s, 4H, O-CH2), 7.35 (s, 2H, Arom. H), 7.36–7.38 (d, 2H, Arom. H), 7.52–7.54 (d, 2H, Arom.
H), 8.24 (s, 2H, Arom. -1,2,3-trz. H), 9.82 (s, 2H, aldehyde-CH); 13C-NMR (
ppm): 26.25 (-CH2-), 28.74
δ ppm): 1.17 (bs, 12H, -CH2-), 1.77 (m, 4H, -CH2-), 3.78 (s, 6H, -OCH3), 4.33 (t, 4H,
δ
(-CH2-), 29.15 (-CH2-), 30.13(-CH2-), 49.83 (N-CH2), 55.91 (-OCH3), 62.22 (O-CH2), Arom. C [110.12
(CH), 113.06 (CH), 125.28 (trz. CH), 126.25 (CH), 130.35 (C), 142.30 (C), 149.74 (trz. C-N), 153.26 (C)],
191.82 (aldehyde-CH); Anal. Calcd (%) for C32H40N6O6 (604.30): C, 63.56; H, 6.67; N, 13.90; found: C,
63.5; H, 6.68; N, 13.92; MS (ESI): m/z (%) 605.36 [M + 1]+.

Molecules 2016, 21, 659
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3.4. Biological Activity
3.4.1. Acetylcholinesterase Inhibition Activity
Acetylcholinesterase inhibition activity was examined using the method described by
Ellman et al. [20] and Inkaninan et al. [21], compared to galantamine as the reference drug. Firstly,
all of the compounds stock solution in DMF (1
concentrations were prepared from stock solution in buffer (Tris-HCI pH 8.00) for experiments. Briefly
50 L of 50 mM Tris-HCl buffer (pH 8.00), 125 L of 3 mM DTNB (in buffer), 25 L of 0.2 U/mL AChE
and 25
L of sample dissolved in buffer and incubated for 15 min. at 25 ˝C. Fifteen minutes later,
25 L of 15 mM acetyl thiocholine iodide were added and incubated 5 min. at room temperature.
ˆ
10´3 M) were prepared and then five different
µ
µ
µ
µ
µ
The reaction was initiated by the addition of acetylcholine iodide. The hydrolysis of this substrate
was monitored by the formation of the yellow 5-thio-2-nitrobenzoate anion as a result of the reaction
DTNB with thiocholine, catalized by enzyme at a wave length of 412 nm using a 96-well microplate
reader (Multiskan Go UV-spectrophotometer, Thermo Fisher Scientific Oy Ratastie 2, Vantaa, Finland).
Inhibition of AChE was calculated by the comparison of reaction rates of the samples relative
to the blank sample (DMF in phosphate buffer pH = 8) using the Equation (1) where Acontrol is the
activity of enzyme without test sample and Asample is the activity of enzyme with test sample:
´
¯
»
fi
Acontrol ´ Asample
–
fl
Scavenging effects p%q “
ˆ 100
(1)
Acontrol
The experiments were carried out in triplicate and IC50 values were examined.
3.4.2. DPPH Radical Scavenging Assay
The compounds were tested for in vitro antioxidant activities by the 2,2-diphenyl-1-picrylhydrazyl
(DPPH) free radical scavenging assay method [22]. The total volume of the assay mixtures containing
methanolic DPPH solution (0.1 mM) and different concentrations of samples was 1 mL. After incubation
in the dark at room temperature for 30 min., absorbance of the samples (Asample) was measured
at 517 nm. Assay mixture without compound was used as control (control absorbance, Acontrol).
All experiments were carried out in triplicate and results were expressed as the mean
deviation (S.D.). Butylatedhydroxyanisole (BHA) were used as the reference compound. Free radical
scavenging effect was calculated using Equation (1).
˘
standard
3.4.3. Superoxide Radical Scavenging Assay
Superoxide scavenging activity of the compounds and reference were tested in a non-enzymatic
superoxide radical (O2´‚) generation assay using a modified spectrophotometrical nitro blue
tetrazolium (NBT) photo reduction method [23]. The total volume of the assay mixtures containing
riboflavin (2 µM), methionine (13 mM), NBT (75 mM), EDTA (0.1 mM), and the test samples (50 mM
˝
phosphate buffer, pH = 7.8) was 1 mL. After illuminating with a fluorescent lamp at 30 C for 10 min.,
the absorbance of the samples (Asample) was measured at 560 nm. Assay mixture without the compound
was used as control (control absorbance, Acontrol). All experiments were carried out in triplicate and
results were expressed as the mean
was calculated using Equation (1).
˘
standard deviation (S.D.). Free O2´‚ radical scavenging effect
3.5. Antimicrobial Activity
All test microorganisms were obtained from the Hifzissihha Institute of Refik
Saydam (Ankara, Turkey) and were the following: Escherichia coli (E. coli) ATCC25922,
Yersinia pseudotuberculosis (Y. pseudotuberculosis) ATCC911, Pseudomonas aeruginosa (P. aeruginosa)
ATCC27853, Staphylococcus aureus (S. aureus) ATCC25923, Enterococcus faecalis (E. faecalis) ATCC29212,

Molecules 2016, 21, 659
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Bacillus cereus (B. cereus) 709ROMA, Mycobacterium smegmatis (M. smegmatis) ATCC607, Candida albicans
(C. albicans) ATCC60193 and Saccharomyces cerevisiae (S. cerevisiae) RSKK251. All the extract compounds
were dissolved in dimethyl sulphoxide (DMSO) to prepare chemicals stock solution of between
460–632 mg/mL.
A simple susceptibility screening test using the agar-well diffusion method [24] as adapted
earlier [25] was used. Each bacterium was suspended in Mueller Hinton (MH) broth (Difco, Detroit,
MI, USA). The yeast-like fungi was suspended in yeast extract broth. Then the microorganisms were
diluted to approximately 106 colony forming unit (cfu) per mL. For yeast-like fungi, potato dextrose
agar (PDA, Difco) was used. Brain heart infusion agar (BHI, Difco, Detriot, MI, USA) was used for
M. smegmatis. Samples were “flood-inoculated” onto the surface of MH, BHI and SD agars and then
dried. Five-millimeter diameter wells were cut from the agar using a sterile cork-borer, and 50
µ
L˝of
the stock extract substances were delivered into the wells. The plates were incubated for 18 h at 35 C.
The Mycobacterium smegmatis was grown for 3 days on BHI agar plates at 35 ˝C [26]. Antimicrobial
activity was evaluated by measuring the zone of inhibition against the test organism. Ampicillin
(10
µg), streptomycin (10 µg) and fluconazole (5 µg) were the standard drugs. Dimethyl sulphoxide
was used as solvent control. The results are shown in Table 2.
Table 2. Screening for antimicrobial activity of the compounds (µg/µL).
Microorganisms and Inhibition Zone
Stock Concentration
Compounds
(µg/mL)
Ec
Yp
Pa
Sa
Ef
Bc
Ms
Ca
Sc
2a
2b
2c
2d
2e
2f
3a
3b
3c
3d
3e
3f
4a
4b
4c
4d
4e
4f
5a
5b
5c
5d
5e
5f
474000
488000
502000
516000
544000
572000
534000
548000
562000
576000
604000
632000
446000
460000
474000
488000
516000
544000
506000
520000
534000
548000
576000
604000
Amp
10
12
12
12
12
10
10
-
8
8
12
8
-
-
10
-
-
8
12
10
10
10
10
8
-
-
-
-
-
-
-
-
6
6
8
6
-
-
-
-
-
8
8
8
8
8
6
6
10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
18
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
35
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
15
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
6
6
-
-
6
-
-
-
-
-
-
-
8
8
6
6
6
-
-
-
-
-
-
-
6
6
-
6
-
-
-
-
-
6
6
6
6
-
-
-
-
-
-
-
-
-
10
Strep
35
Flu.
25
25
Ec: E. coli ATCC 35218; Yp: Y. pseudotuberculosis ATCC 911; Pa: P. aeruginosa ATCC 10145; Sa: S. aureus ATCC
25923; Ef: E. faecalis ATCC 29212; Bc: B. cereus 709 Roma; Ms: M. smegmatis ATCC607; Ca: C. albicans ATCC
60193; S. cerevisiae RSKK 251; Amp.: Ampicillin; Strep.: Streptomycin; Flu.: Fluconazole; (-): no activity of
test concentrations.
4. Conclusions
In this study, a series of new bis-1,2,3-triazole derivatives having flexible alkyl chains connected to
a phenoxy ring were synthesized and characterized. All spectra of these compounds were submitted

Molecules 2016, 21, 659
12 of 13
in the supplementary materials. Antioxidant and antimicrobial assays were performed for all of the
synthesized compounds. Biological activity assays (AChE inhibition, DPPH and SOD activities) were
performed for all the compounds. Compound 2f was found to display the highest AChE inhibition
activity of all compounds. Compound 3b showed a strong inhibitory effect on DPPH radicals. All other
compounds showed moderate activities compared to BHA. Compound 2a was the most effective of
all compounds for SOD activity. The results of this study suggest that 1,2,3-triazole compounds have
potential neuroprotective effects due to their acetylcholinesterase inhibition and antioxidant activities.
All newly synthesized compounds were screened for their antibacterial activities by the inhibition
zone (mm) method. All compounds were found to possess moderately antibacterial activity against
the bacteria E. coli, and Y. pseudotuberculosis and antimycotic effects were observed at very low levels
against S. cerevisiae and C. albicans in some molecules.
Supplementary Materials: Supplementary materials can be accessed at: http://www.mdpi.com/1420-3049/21/
5/659/s1.
Acknowledgments: This was carried out by the research fund of Karadeniz Technical University.
Author Contributions: Esra Düg˘dü and Kemal Sancak conceived and designed the experiments; Dilek Ünlüer and
Fatih Çelik performed the experiments; S¸engül Alpay Karaog˘lu, Arzu Özel performed the biological experiments
and analyzed the data; Esra Düg˘dü and Fatih Çelik analyzed the spectral data; Esra Düg˘dü wrote the paper.
We also wish to thank Burak BARUT for him help biological experiments..
Conflicts of Interest: The authors declare no conflict of interest.
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2016 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access
article distributed under the terms and conditions of the Creative Commons Attribution
(CC-BY) license (http://creativecommons.org/licenses/by/4.0/).