An efficient ultrasound-assisted method for the synthesis of 1,4-Disubstituted triazoles

Article abstract of DOI:10.1515/znb-2011-0113

An efficient method for the synthesis of 1,4-disubstituted triazoles has been developed with the help of ultrasound irradiation in water at room temperature. Under the optimized conditions, a novel series of 1,4-disubstituted 1,2,3-triazoles was synthesiz

Full text of DOI:10.1515/znb-2011-0113

An Efficient Ultrasound-assisted Method for the Synthesis
of 1,4-Disubstituted Triazoles
Yuqin Jianga,c, Xiaolan Chena, Lingbo Qua,b, Junliang Wanga, Jinwei Yuanb,
Senshen Chena, and Xu Lia
a Key Laboratory of Organic Chemistry and Chemical Biology, Henan Province, Department
of Chemistry, Zhengzhou University, Zhengzhou, 450052, China
b Henan University of Technology, Henan Province, Zhengzhou 450052, China
c College of Chemistry and Environmental Science, Henan Normal University,
Xinxiang, 453007, China
Reprint requests to Prof. Xiao Lan Chen. Fax: +86-371-67767051. E-mail: chenxl@zzu.edu.cn
Z. Naturforsch. 2011, 66b, 77 – 82; received September 6, 2010
An efficient method for the synthesis of 1,4-disubstituted triazoles has been developed with the
help of ultrasound irradiation in water at room temperature. Under the optimized conditions, a novel
series of 1,4-disubstituted 1,2,3-triazoles was synthesized in high yields.
Key words: Huisgen Cycloaddition, Cu(OAc)2/Cu Wire, Ultrasound, 1,4-Disubstituted Triazole
Introduction
trasound approach are enhanced reaction rates, forma-
tion of pure products in high yields, and easier manip-
ulation [10, 11]. However, only a few 1,3-dipolar cy-
cloadditions promoted by ultrasound irradiation have
been reported. Reddy described a three-component re-
action catalyzed by CuI with the help of ultrasound ir-
radiation, by which the corresponding 1,2,3-triazoles
were obtained in a one-pot reaction using substituted
benzyl chlorides, sodium azide and alkyne as reac-
tants. The disadvantage of the one-pot method is that
the influence of ultrasound on the essential step of
1,3-dipolar cycloadditions can not be explored directly
[12]. Cravotto chose only metallic copper as a cata-
lyst for the investigation of the 1,3-dipolar cycloaddi-
tion in 1,4-dioxane/water with the help of ultrasound
irradiation, however, a relatively high temperature was
needed [13, 14]. It is known that organic reactions
in water are of great interest especially in relation
to today’s environmental concerns. However, the 1,3-
dipolar cycloaddition in water was necessarily carried
out in the presence of a ligand or a base, otherwise a
long reaction time would be necessary [15 – 19]. In the
work described in this paper, an efficient method for
1,3-dipolar cycloadditions under relatively mild and
environmentally friendly conditions is established, in-
volving Cu(OAc)2/metallic copper as a catalyst system
and water as reaction medium with the help of ultra-
sound irradiation in the absence of the related ligand
or a base.
The classical Huisgen 1,3-dipolar cycloaddition re-
action of organic azides and alkynes, studied by Huis-
gen and co-workers in the 1960s [1], has recently re-
gained attention, owing to the discovery that the rate of
the cycloaddition can be accelerated greatly by Cu(I)
catalysis [2, 3]. The active Cu(I) ion can be generated
directly from Cu(I) salts or in situ from Cu(II) salts in
the presence of a reducing agent (often sodium ascor-
bate or metallic copper). Usually Cu(I) salts are used in
organic or aqueous solvents together with a base or a
ligand [2 – 4]. Cu(II) salts in the presence of sodium
ascorbate have been successfully applied to the 1,3-
dipolar cycloaddition, except in special circumstances,
when the reactants are reduced by sodium ascorbate
in situ [5]. It was reported that metallic copper can
replace sodium ascorbate as a reducing agent to gen-
erate Cu(I) ions by the comproportionation of Cu(0)
and Cu(II). The reduction of the reactants can often
be avoided by using metallic copper as a less reduc-
tive agent. Compared to catalyst systems composed of
Cu(I) salts and Cu(II) salts/sodium ascorbate, reactions
catalyzed by a Cu(II) salt/Cu catalyst system usually
need relatively long reaction times at room tempera-
ture [6 – 9].
Ultrasound-assisted organic synthesis, as a synthetic
approach, is a powerful technique that is used to accel-
erate organic reactions. The notable features of the ul-
c
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Y. Jiang et al. · An Efficient Ultrasound-assisted Method for the Synthesis of 1,4-Disubstituted Triazoles
Scheme 1. Model reaction of cy-
cloaddition under ultrasound at
room temperature.
Table 1. Screening of catalysts for the synthesis of triazoles
(Scheme 1) in water at room temperature under ultrasound
irradiation.
Entry
Catalyst system
CuSO4/Cu wire
CuCl2/Cu wire
CuBr2/Cu wire
Cu (NO3)2/Cu wire
Cu(ClO4)2/Cu wire
Cu(OAc)2/Cu wire
Cu(OAc)2·H2O
Cu wire
Time (min)
120
120
120
120
120
20
120
120
Yield (%)a
88
62
52
52
20
92
70
trace
80
1
2
3
4
5
6
7
8
9
Cu(OAc)2/Cu wireb
1200
a
Isolated yield; b without ultrasound irradiation.
Results and Discussion
Fig. 1. Reaction time versus catalyst loading of copper wire
by fixing the loading (5 mol-%) of Cu(OAc)2 for the model
reaction.
Initially, different cupric salts (5 mol-%) together
with copper wire (100 mol-%) shown in Table 1 were
screened for their catalytic efficiency in the 1,3-dipolar
cycloaddition. Propargyl phenyl ether (1) [20] and
ethyl 2-azidoacetate (2) [21] were used as representa-
tive substrates in this screening (Scheme 1). All the
reactions were carried out in water under continu-
ous sonication for 120 min. Among the tested cat-
alysts the best catalytic efficiency was observed for
Cu(OAc)2/Cu wire. Most notably, the 1,3-dipolar cy-
cloaddition reaction catalyzed by Cu(OAc)2/Cu wire
was completed within 20 min in 92 % yield (Table 1).
In comparision to Cu(OAc)2/Cu wire, lower catalytic
efficiencies were observed for other cupric salt/Cu wire
catalysts, among which Cu(ClO4)2/Cu wire showed
the lowest (20 % yield) and CuSO4/Cu wire the highest
(88% yield). It is worth to mention that nearly no cat-
alytic effect was observed for Cu wire within 120 min,
wheras a relatively high efficiency was observed for
Cu(OAc)2·H2O (70 % yield within 120 min). The cat-
alytic efficiency of the cupric salt/Cu wire increases
in the order Cu(ClO4)2/Cu wire, Cu(NO3)2/Cu wire,
CuBr2/Cu wire, CuCl2/Cu wire, CuSO4/Cu wire and
Cu(OAc)2/Cu wire.
of Cu(I) generated from the comproportionation of
Cu(OAc)2/Cu wire in situ, the faster was the rate
of the reaction [22]. As can be seen from Fig. 1,
the reaction time decreased with increasing amounts
of copper wire until the amount of copper wire
was raised to 150 mol-%, indicating that at least
150 mol-% copper wire was needed to provide a suf-
ficient surface area exposed to Cu(OAc)2 for acceler-
ating the comproportionation. The cycloaddition can
be complete within 10 min with a concentration of
150 mol-% copper wire. Cu(OAc)2 (5 mol-%)/Cu wire
(150 mol-%) was finally chosen as an appropriate
composition of a catalyst for the 1,3-dipolar cyclo-
addition.
In order to investigate the influence of ultrasound
on the 1,3-dipolar cycloaddition, the following ex-
periment was designed. The cycloaddition catalyzed
by Cu(OAc)2/Cu wire was carried out in water at
room temperature in the absence or presence of ul-
trasound irradiation. According to TLC monitoring,
20 h were required to complete the cycloaddition
reaction in the absence of ultrasound irradiation in
In order to investigate the influence of the amounts 80 % yield, but only 10 min in the presence of ul-
of copper wire in the Cu(OAc)2/Cu wire catalyst trasound irradiation in 92 % yield, showing that the
system, the cycloaddition reactions were performed ultrasound irradiation greatly accelerates the reaction
with gradually varied amounts of copper wire, from and enhances the yield. In all, the optimized relative
5 mol-% to 200 mol-% with a fixed amount of quantities of reactants, catalyst and solvent are: or-
Cu(OAc)2 (5 mol-%). The higher the concentration ganic azide (1.0 mmol), terminal alkyne (1.0 mmol),
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Y. Jiang et al. · An Efficient Ultrasound-assisted Method for the Synthesis of 1,4-Disubstituted Triazoles
79
Scheme 2. Syn-
thesis of com-
pounds 4 – 16.
Table 2. Synthesis of 1,4-disubstituted 1,2,3-triazoles.
40 kHz and a power of 150 W. IR spectra were recorded
on a Shimadazu IR-408 spectrometer. 1H and 13C spectra
were recorded on a Bruker 400 spectrometer operating at
400.13 and 100.61 MHz, respectively, with 13C spectra be-
ing recorded proton-decoupled. 1H and 13C chemical shifts
are quoted in parts per million downfield from TMS. ESI
MS were recorded on a Bruker Esquire 3000 instrument.
High-resolution mass spectra (HRMS) were performed on
a Micromass Q-TOF MicroTM mass spectrometer with an
ESI source (Waters, Manchester, UK). Substituted terminal
alkynes were synthesized according to the literature [20, 23 –
26]. Benzyl azide [21] and phenyl azide [27] were also syn-
thesized according to previous reports.
Compound R1
R2
H
H
OMe
OMe
H
R3
H
H
H
H
R4
Time (min) Yield (%)
4
OMe
OMe
H
benzyl
phenyl
benzyl
phenyl
30
30
30
30
35
70
80
80
80
40
45
45
40
99
96
97
95
99
95
91
99
97
92
90
92
90
5
6
7
H
8
H
NO2
H
Cl
Cl
H
H
H
Me
OMe benzyl
benzyl
NO2 benzyl
9
H
H
H
H
H
10
11
12
13
14
15
16
Cl
Cl
Cl
H
benzyl
phenyl
benzyl
benzyl
phenyl
benzyl
H
Me
Me
H
H
H
General procedure for the synthesis of triazoles
Cu(OAc)2·H2O (5 mol-%)/Cu wire (150 mol-%) and
water (5 mL).
A mixture of organic azide (1.0 mmol), terminal alkyne
(1.0 mmol), Cu(OAc)2·H2O/Cu wire (10 mol-%) in water
(5 mL) was sonicated for the time indicated in Table 2 in
a laboratory ultrasonic cleaning bath at r. t. After comple-
tion of the reaction as indicated by TLC, the reaction mix-
ture was diluted with saturated aq. NH4Cl (20 mL) and ex-
tracted with CH2Cl2 (3 × 15 mL). The combined organic
layers were washed with brine (10 mL) and dried over an-
hydrous Na2SO4 and filtered. The solvent of the filtrate was
removed in vacuo to give the pure product.
A series of 1,4-disubstituted 1,2,3-triazole deriva-
tives were synthesized based on the optimized condi-
tions (Scheme 2, Table 2). As shown in Table 2, reac-
tions between substituted terminal alkynes and organic
azides, including benzyl azide and phenyl azide, under
the optimized conditions gave 1, 4-disubstituted 1,2,3-
triazoles in good yields.
In summary, a highly efficient synthesis of 1,4-
disubstituted 1,2,3-triazoles in water was developed
by using Cu(OAc)2/Cu wire as the catalyst with ultra-
sound irradiation.
1-Benzyl-4-[(2-methoxyphenoxy)methyl]-1,2,3-triazole (4)
M. p. 112 – 114 ◦C. – IR (KBr): νmax (cm−1) = 3131,
3034, 2968, 2930, 2878, 1388, 2834, 1590, 1503, 1453,
1251, 1216, 1122, 1028. – 1H NMR (400 MHz, CDCl3): δ =
7.57 (s, 1H, 9-H), 7.39 – 7.36 (m, 3H, 13, 14, 15-H), 7.27
Experimental Section
General
All the chemicals were obtained from Tianjin Kermel (dd, J = 2.0, 7.2 Hz, 2H, 12, 16-H), 7.06 – 7.04 (dd, J = 2.0,
Chemical Reagent Co., Ltd. and used as received. Melt- 8.0 Hz, 1H, 6-H), 6.98 – 6.94 (td, J = 2.0, 8.0 Hz, 1H, 4-H),
ing points were recorded on an electrothermal appara- 6.91 – 6.88 (m, 2H, 3, 5-H), 5.53 (s, 2H, 10-H), 5.28 (s, 2H,
tus and are uncorrected. Sonication was performed in a 7-H), 3.85 (s, 3H, -OMe). – 13C NMR (100 MHz, CDCl3):
Kunshan KQ-250B ultrasonic cleaner with a frequency of δ = 149.6, 147.6, 144.5, 134.6, 129.0, 128.7, 128.1, 123.1,
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Y. Jiang et al. · An Efficient Ultrasound-assisted Method for the Synthesis of 1,4-Disubstituted Triazoles
121.9, 120.8, 114.4, 111.8, 63.1, 55.7, 54.0. – MS (ESI): 2H, 12, 16-H), 6.91 (d, J = 9.2 Hz, 2H, 2, 6-H), 6.83 (d,
m/z (%) = 296 (100) [M+H]+. – HRMS ((+)-ESI): m/z = J = 9.2 Hz, 2H, 3, 5-H), 5.54 (s, 2H, 10-H), 5.15 (s, 2H,
296.1404 (calcd. 296.1399 for C17H18N3O2, [M+H]+).
7-H), 3.77 (s, 3H, -OMe). – 13C NMR (100 MHz, CDCl3):
δ = 154.2, 152.3, 144.7, 134.6, 129.1, 128.7, 128.1, 122.8,
115.9, 114.6, 62.7, 55.6, 54.1. – MS (ESI): m/z (%) = 296
(100) [M+H]+. – HRMS ((+)-ESI): m/z = 296.1397 (calcd.
296.1399 for C17H18N3O2, [M+H]+).
4-[(2-Methoxyphenoxy)methyl]-1-phenyl-1,2,3-triazole (5)
M. p. 130 – 132 ◦C. – IR (KBr): νmax (cm−1) = 3150,
3084, 2955, 2922, 2876, 2835, 1385, 1592, 1503, 1465,
1250, 1218, 1126, 1024. – 1H NMR (400 MHz, CDCl3):
δ = 8.10 (s, 1H, 9-H), 7.74 – 7.72 (dd, J = 1.2, 7.6 Hz,
2H, 11, 15-H), 7.53 (t, J = 7.6 Hz, 2H, 12, 14-H), 7.45 (t,
J = 7.6 Hz, 1H, 13-H), 7.12 – 7.10 (dd, J = 1.6, 8.0 Hz,
1H, 3-H), 6.99 – 6.96 (dd, J = 1.6, 8.0 Hz, 1H, 5-H),
6.94 – 6.92 (m, 2H, 4, 6-H), 5.39 (s, 2H, 7-H), 3.90 (s,
3H, -OMe). – 13C NMR (100 MHz, CDCl3): δ = 149.5,
147.5, 145.1, 137.0 , 129.8, 128.8, 122.0, 121.1, 120.9,
120.6, 114.2, 111.2, 63.1, 55.9. – MS (ESI): m/z (%) = 282
(100) [M+H]+. – HRMS((+)-ESI): m/z = 282.1243 (calcd.
282.1238 for C16H16N3O2, [M+H]+).
1-Benzyl-4-[(2-nitrophenoxy)methyl]-1,2,3-triazole (9)
M. p. 107 – 108 ◦C. – IR (KBr): νmax (cm−1) = 3151,
3088, 3056, 2928, 1616, 1585, 1456, 1529, 1340, 1274,
1
1161, 1045. – H NMR (400 MHz, CDCl3): δ = 7.85 (dd,
J= 1.6, 8.1 Hz, 1H, 3-H), 7.67 (s, 1H, 9-H), 7.58 – 7.53 (td,
J = 1.6, 7.6, 8.0 Hz, 1H, 5-H), 7.40 – 7.37 (m, 3H, 13, 14,
15-H), 7.30 – 7.27 (m, 3H, 6, 12, 16-H), 7.07 (td, J = 1.2,
7.6 Hz, 1H, 4-H), 5.55 (s, 2H, 10-H), 5.37 (s, 2H, 7-H). –
13C NMR (100 MHz, CDCl3): δ = 151.5, 143.6, 140.0,
134.5, 134.3, 129.1, 128.8, 128.0, 125.6, 123.3, 121.1, 115.4,
63.7, 54.2. – MS (ESI): m/z (%) = 311 (100) [M+H]+. –
HRMS ((+)-ESI): m/z = 311.1149 (calcd. 311.1144 for
C16H15N4O3, [M+H]+).
1-Benzyl-4-[(3-methoxyphenoxy)methyl]-1,2,3-triazole (6)
M. p. 84 – 86 ◦C. – IR (KBr): νmax (cm−1) = 3138, 3093,
2933, 2875, 1384, 1596, 1495, 1462, 1231, 1193, 1121,
1053, 1024, 1012. – 1H NMR (400 MHz, CDCl3): δ =
7.54 (s, 1H, 9-H), 7.40 – 7.38 (m, 3H, 13, 14, 15-H), 7.30 –
7.28 (dd, J = 2.4, 7.2 Hz, 2H, 12, 16-H), 7.19 (t, J =
8.4 Hz, 1H, 5-H), 6.59 – 6.53 (m, 3H, 2, 4, 6-H), 5.55 (s,
2H, 10-H), 5.18 (s, 2H, 7-H), 3.78 (s, 3H, -OMe). – 13C
NMR (100 MHz, CDCl3): δ = 160.8, 159.5, 44.5, 134.5,
130.0, 129.1, 128.8, 128.1, 122.8, 107.0, 106.8, 101.2, 62.0,
55.3, 54.2. – MS (ESI): m/z (%) = 296 (100) [M+H]+. –
HRMS ((+)-ESI): m/z = 296.1397 (calcd. 296.1399 for
C17H18N3O2, [M+H]+).
1-Benzyl-4-[(4-nitrophenoxy)methyl]-1,2,3-triazole (10)
M. p. 103 – 104 ◦C. – IR (KBr): νmax (cm−1) = 3147,
3116, 1606, 1494, 1337, 1267, 1114, 1055. – 1H NMR
(400 MHz, CDCl3): δ = 8.21 (d, J = 9.2 Hz, 2H, 3, 5-H), 7.57
(s, 1H, 9-H), 7.42 – 7.39 (m, 3H, 13, 14, 15-H), 7.31 – 7.27
(dd, J = 3.2, 7.6 Hz, 2H, 12, 16-H), 7.07 (d, J = 9.2 Hz, 2H,
2, 6-H), 5.57 (s, 2H, 10-H), 5.28 (s, 2H, 7-H). – 13C NMR
(100 MHz, CDCl3): δ = 163.2, 143.0, 141.7, 134.4, 129.2,
128.9, 128.2, 125.9, 123.3, 114.8, 62.4, 54.3. – MS (ESI):
m/z (%) = 311 (100) [M+H]+. – HRMS ((+)-ESI): m/z =
311.1148 (calcd. 311.1144 for C16H15N4O3, [M+H]+).
4-[(3-Methoxyphenoxy)methyl]-1-phenyl-1,2,3-triazole (7)
1-Benzyl-4-[(2,4-dichlorophenoxy)methyl]-1,2,3-triazole
M. p. 104 – 106 ◦C. – IR (KBr): νmax (cm−1) = 3141,
2910, 1594, 1510, 1461, 1370, 1230, 1109, 1041. – 1H NMR
(400 MHz, CDCl3): δ = 8.07 (s, 1H, 9-H), 7.77 – 7.74 (dd,
J = 1.6, 7.2 Hz, 2H, 11, 15-H), 7.54 (t, J = 7.2 Hz, 2H, 12,
14-H), 7.46 (dd, J = 1.6, 7.2 Hz, 1H, 13-H), 7.23 (t, J =
8.0 Hz, 1H, 5-H), 6.65 (dd, J = 2.4, 8.0 Hz, 1H, 6-H), 6.61
(t, J = 2.4 Hz, 1H, 2-H), 6.57 (dd, J = 2.4, 8.0 Hz, 1H, 4-H),
5.30 (s, 2H, 7-H), 3.81 (s, 3H, -OMe). – 13C NMR (100 MHz,
CDCl3): δ = 160.9, 159.5, 144.8, 136.9, 130.1, 129.8, 128.9,
121.1, 120.5, 107.0, 106.8, 101.3, 61.9, 55.3. – MS (ESI):
m/z (%) = 282 (100) [M+H]+. – HRMS ((+)-ESI): m/z =
282.1243 (calcd. 282.1238 for C16H16N3O2, [M+H]+).
(11)
M. p. 88 – 90 ◦C. – IR (KBr): νmax (cm−1) = 3142, 3036,
2928, 1586, 1485, 1468, 1289, 1249, 1103, 1066. – 1H NMR
(400 MHz, CDCl3): δ = 7.59 (s, 1H, 9-H), 7.40 – 7.37 (m,
3H, 13, 14, 15-H), 7.36 (d, J = 2.8 Hz, 1H, 3-H), 7.30 (dd,
J = 2.8, 6.8 Hz, 2H, 12, 16-H), 7.18 (dd, J = 2.4, 8.8 Hz,
1H, 5-H), 7.05 (d, J = 8.8 Hz, 1H, 6-H), 5.55 (s, 2H, 10-H),
5.26 (s, 2H, 7-H). – 13C NMR (100 MHz, CDCl3): δ =
152.5, 143.7, 134.5, 123.0, 129.1, 128.8, 128.1, 127.7, 126.4,
123.8, 123.1, 115.1, 63.4, 54.2. – MS (ESI): m/z (%) = 334
(100) [M+H]+. – HRMS ((+)-ESI): m/z = 334.0511 (calcd.
334.0514 for C16H14Cl2N3O, [M+H]+).
1-Benzyl-4-[(4-methoxyphenoxy)methyl]-1,2,3-triazole (8)
4-[(2,4-Dichlorophenoxy)methyl]-1-phenyl-1,2,3-triazole
(12)
M. p. 86 – 88 ◦C. – IR (KBr): νmax (cm−1) = 3124, 3082,
2948, 2928, 2831, 1510, 1454, 1233, 1119, 1048. – 1H
M. p. 117 – 119 ◦C. – IR (KBr): νmax (cm−1) = 3156,
NMR (400 MHz, CDCl3): δ = 7.52 (s, 1H, 9-H), 7.40 – 3096, 3034, 2921, 2874, 1739, 1291, 1596, 1506, 1491,
7.37 (m, 3H, 13, 14, 15-H), 7.29 – 7.26 (dd, J = 2.8, 7.2 Hz, 1451, 1248, 1105, 1059, 1043. – 1H NMR (400 MHz,
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Y. Jiang et al. · An Efficient Ultrasound-assisted Method for the Synthesis of 1,4-Disubstituted Triazoles
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CDCl3): δ = 8.12 (s, 1H, 9-H), 7.76 (d, J = 8.0 Hz, 2H, 1-Phenyl-4-(m-tolyloxymethyl)-1,2,3-triazole (15)
11, 15-H), 7.56 (t, J = 8.0 Hz, 2H, 12, 14-H), 7.47 (t, J =
M. p. 87 – 89 ◦C. – IR (KBr): νmax (cm−1) = 3141, 3062,
2926, 2870, 1378, 1599, 1585, 1503, 1461, 1259, 1157,
1046. – 1H NMR (400 MHz, CDCl3): δ = 8.06 (s, 1H, 9-H),
7.75 (d, J = 8.0 Hz, 2H, 11, 15-H), 7.55 (t, J = 8.0 Hz,
2H, 12, 14-H), 7.46 (t, J = 7.2 Hz, 1H, 13-H), 7.21 (t, J =
7.6 Hz, 1H, 5-H), 6.88 – 6.80 (m, 3H, 2, 4, 6-H), 5.31 (s, 2H,
7-H), 2.36 (s, 3H, -Me). – 13C NMR (100 MHz, CDCl3): δ =
158.2, 145.1, 139.7, 137.0, 129.8, 129.4, 128.9, 122.2, 121.0,
120.5, 115.6, 111.6, 61.9, 21.6. – MS (ESI): m/z (%) = 266
(100) [M+H]+. – HRMS ((+)-ESI): m/z = 266.1290 (calcd.
266.1293 for C16H17N3O, [M+H]+).
7.6 Hz, 1H, 13-H), 7.40 (d, J = 2.4 Hz, 1H, 3-H), 7.22
(dd, J = 2.4, 8.8 Hz, 1H, 5-H), 7.11 (d, J = 8.8 Hz, 1H,
6-H), 5.38 (s, 2H, 7-H). – 13C NMR (100 MHz, CDCl3):
δ = 151.5, 144.1, 136.8, 130.1, 129.8, 129.0, 127.7, 126.4,
123.8, 121.3, 120.5, 114.9, 63.3. – MS (ESI): m/z (%) = 320
(100) [M+H]+. – HRMS ((+)-ESI): m/z = 320.0357 (calcd.
320.0362 for C15H12Cl2N3O, [M+H]+).
1-Benzyl-4-[(4-chlorophenoxy)methyl]-1,2,3-triazole (13)
M. p. 99 – 100 ◦C. – IR (KBr): νmax (cm−1) = 3141, 2928,
2875, 1594, 1492, 1457, 1241, 1126, 1055. – 1H NMR
(400 MHz, CDCl3): δ = 7.53 (s, 1H, 9-H), 7.40 – 7.38 (m,
3H, 13, 14, 15-H), 7.30 (dd, J = 2.8, 7.2 Hz, 2H, 12, 16-H),
7.24 (d, J = 7.2 Hz, 2H, 3, 5-H), 6.91 (d, J = 7.2 Hz, 2H,
2, 6-H), 5.55 (s, 2H, 10-H), 5.16 (s, 2H, 7-H). – 13C NMR
(100 MHz, CDCl3): δ = 156.8, 144.1, 134.4, 129.4, 129.2,
128.9, 128.1, 126.1, 122.8, 116.1, 62.2, 54.2. – MS (ESI):
m/z (%) = 300 (100) [M+H]+. – HRMS ((+)-ESI): m/z =
300.0906 (calcd. 300.0904 for C16H15ClN3O, [M+H]+).
1-Benzyl-4-(o-tolyloxymethyl)-1,2,3-triazole (16)
M. p. 66 – 68 ◦C. – IR (KBr): νmax (cm−1) = 3145, 3031,
2928, 1602, 1591, 1496, 1466, 1381, 1246, 1126, 1056. – 1H
NMR (400 MHz, CDCl3): δ = 7.53 (s, 1H, 9-H), 7.40 – 7.37
(m, 3H, 13, 14, 15-H), 7.30 (dd, J = 2.4, 8.0 Hz, 2H, 12,
16-H), 7.16 (t, J = 7.6 Hz, 2H, 3, 5-H), 6.95 (d, J = 8.0 Hz,
1H, 6-H), 6.89 (t, J = 7.6 Hz, 1H, 4-H), 5.56 (s, 2H, 10-H),
5.22 (s, 2H, 7-H), 2.21 (s, 3H, -Me). – 13C NMR (100 MHz,
CDCl3): δ = 156.4, 145.0, 134.7, 130.8, 129.1, 128.8, 128.0,
127.0, 126.9, 122.6, 121.0, 111.6, 62.3, 54.1, 16.4. – MS
(ESI): m/z (%) = 280 [M+H]+. – HRMS ((+)-ESI): m/z =
280.1452 (calcd. 280.1450 for C17H18N3O, [M+H]+).
1-Benzyl-4-(m-tolyloxymethyl)-1,2,3-triazole (14)
M. p. 78 – 80 ◦C. – IR (KBr): νmax (cm−1) = 3136, 3032,
2925, 2874, 1605, 1582, 1487, 1458, 1383, 1256, 1153,
1040. – 1H NMR (400 MHz, CDCl3): δ = 7.53 (s, 1H, 9-H),
7.42 – 7.37 (m, 3H, 13, 14, 15-H), 7.29 (dd, J = 2.8, 8.0 Hz,
2H, 12, 16-H), 7.17 (t, J = 8.0 Hz, 1H, 5-H), 6.80 – 6.77 (m,
3H, 2, 4, 6-H), 5.55 (s, 2H, 10-H), 5.19 (s, 2H, 7-H), 2.33 (s,
3H, -Me). – 13C NMR (100 MHz, CDCl3): δ = 158.2, 144.8,
139.6, 134.6, 129.3, 129.2, 128.8, 128.1, 122.6, 122.1, 115.6,
111.6, 62.0, 54.2, 21.6. – MS (ESI): m/z (%) = 280 (100)
[M+H]. – HRMS ((+)-ESI): m/z = 280.1454 (calcd. 280.1450
for C17H18N3O, [M+H]+).
Acknowledgement
The authors would like to thank the National Natural Sci-
ence Foundation of China (No. 21072178) and the Innova-
tion Specialist Projects of Henan Province for their financial
support.
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