Syntheses, crystal structures, and spectral characterization of two novel quinolyl substituted triazoles

Article abstract of DOI:10.1002/jhet.1611

Two novel quinolyl substituted triazoles, 3-(p-methoxyphenyl)-4-amino-5-(2- quinolyl)-1,2,4-triazole (5) and 3-(p-methoxyphenyl)-4-phenyl-5-(2-quinolyl)-1, 2,4-triazole (6), were successfully synthesized. The compound 5 was synthesized under solvothermal

Full text of DOI:10.1002/jhet.1611

Month 2013 Syntheses, Crystal Structures, and Spectral Characterization of Two Novel
Quinolyl Substituted Triazoles
*
*
Guo-Ping Shen, Jing-Jing Jiang, Feng Sun, Xuan Shen, Dun-Ru Zhu, and Xiao-Qin Liu
College of Chemistry and Chemical Engineering, State Key Laboratory of Materials-oriented Chemical Engineering,
Nanjing University of Technology, Nanjing 210009, China
*
E-mail: zhudr@njut.edu.cn
Additional Supporting Information may be found in the online version of this article.
Received November 4, 2011
DOI 10.1002/jhet.1611
Published online 00 Month 2013 in Wiley Online Library (wileyonlinelibrary.com).
Two novel quinolyl substituted triazoles, 3-(p-methoxyphenyl)-4-amino-5-(2-quinolyl)-1,2,4-triazole (5)
and 3-(p-methoxyphenyl)-4-phenyl-5-(2-quinolyl)-1,2,4-triazole (6), were successfully synthesized. The
compound 5 was synthesized under solvothermal conditions, whereas 6 was prepared through a solution
1
method. Both 5 and 6 were characterized with UV–vis, FTIR, H-NMR, ESI-MS spectra, and elemental
analysis. Additionally, the absolute configurations of 5 and 6 were determined by single-crystal X-ray
crystallography.
J. Heterocyclic Chem.,, 00, 00 (2013).
INTRODUCTION
(a) and (b). However, we did not obtain the quinolyl substi-
tuted 1,2,4-triazoles by method (a). Hence, we chose
method (b) for the syntheses of compounds 5 and 6. The
synthetic route of 5 and 6 was shown in Scheme 1. It is
worthwhile to note that compound 5 was synthesized under
solvothermal conditions, whereas 6 was prepared through a
solution method.
The readily available quinoline-2-carboxylic acid reacting
with anhydrous ethanol under the existence of 98% concen-
trated sulfuric acid gave ethyl quinoline-2-carboxylic acid
(1). Brief treatment of 1 with 85% hydrazine hydrate afforded
2-quinolylhydrazine (2) in 51.4% yield. N-(p-methoxyphenyl-
carbonyl)-N0-(2-quinolinecarbonyl)hydrazine (3) [25] was
obtained in a yield of 78.3% by stirring 2 with anisoyl
chloride in anhydrous pyridine. 1,4-Dichloro-1-(2-quinolyl)-
4-(p-methoxyphenyl)-2,3-diaza-1,3-butadiene (4) [26] was
obtained in a yield of 73.5% by stirring 3 with thionyl
chloride in anhydrous toluene. Finally, the cyclization
reaction of 4 with anhydrous hydrazine under solvothermal
conditions at 120ꢀC for 4 h produced 5 in a yield of
74.2%, whereas cyclization reaction of 4 with aniline at
190 ꢀC for 3 h produced 6 in a yield of 75.9% under argon
atmosphere.
Substituted 1,2,4-triazoles have been reported to
show a variety of pharmacological activities such as
anti-inflammatory, antitumor, fungicide, weedicide, and so
on [1]. Moreover, substituted 1,2,4-triazoles also have
attracted considerable attention in coordination chemistry
because of their rich and versatile coordination modes [2,3].
Some iron(II) complexes containing substituted 1,2,4-triazole
ligands especially have spin-crossover properties that can be
used as molecular-based electronics, displays, and optical
switches [4–8].
Although a lot of 1,2,4-triazole compounds with substituted
alkyl, phenyl, or pyridyl [9–18] have been synthesized
successfully, substituted 1,2,4-triazoles with quinolyl group,
an important alkaloid with stronger conjugated system, have
been little reported so far [19–23]. As a continuation of our
investigation on the substituted 1,2,4-triazoles, herein,
we present the first syntheses of two quinolyl substituted
1,2,4-triazoles, 3-(p-methoxyphenyl)-4-amino-5-(2-qui-
nolyl)-1,2,4-triazole (5), and 3-(p-methoxyphenyl)-4-phe-
nyl-5-(2-quinolyl)-1,2,4-triazole (6). Both 5 and 6 were
1
characterized with UV–vis, FTIR, H-NMR, ESI-MS spec-
tra, elemental analysis, and single-crystal X-ray diffraction.
Both 5 and 6 were characterized with UV–vis, FTIR,
1H-NMR, ESI-MS spectra, and elemental analysis. The
molecular structures of 5 and 6 were also confirmed by
X-ray crystallography. Single crystals of 5 and 6ꢁ0.25
(Me2CO) suitable for X-ray diffraction study were
obtained upon slow evaporation from acetone solution at
ambient temperature. The crystal structures of 5 and
6ꢁ0.25(Me2CO) with atom-labeling scheme are shown in
RESULTS AND DISCUSSION
In general, there are three kinds of methods reported for
the preparation of substituted 1,2,4-triazoles (see Scheme 2
in ref. [24]). There is a complicated route and the lower
yield of the triazole in method (c) compared with methods
© 2013 HeteroCorporation

G-P. Shen, J-J. Jiang, F. Sun, X. Shen, D-R. Zhu, and X-Q. Liu
Vol 000
Scheme 1
EXPERIMENTAL
Figure 1, and selected bond lengths and bond angles are
listed in Table 1. The X-ray crystallography analysis
indicates that 5 consists of one quinolyl ring, one aryl
ring, and one 1,2,4-triazole ring, and these rings almost
share a common plane, whereas 6 consists of one
quinolyl ring, two aryl rings, and one 1,2,4-triazole
ring, and these rings do not share a common plane.
The bond lengths and bond angles of 5 and 6ꢁ0.25
(Me2CO) are similar and in the normal ranges [23].
However, the dihedral angles of 5 are quite smaller than
those of 6ꢁ0.25(Me2CO) (Table 2). There are six types
of hydrogen bonds and three types of C–Hꢁꢁꢁp interac-
tions in 5 whereas just two types of hydrogen bonds
and one type of C–Hꢁꢁꢁp interaction in 6ꢁ0.25(Me2CO).
The hydrogen bonds of 5 and 6ꢁ0.25(Me2CO) are
summarized in Table 3. The C–Hꢁꢁꢁp interactions of 5
and 6ꢁ0.25(Me2CO) are listed in Table 4. These hydro-
gen bonds and C–Hꢁꢁꢁp interactions are helpful to
stabilize the crystal packing of 5 and 6. The crystal
packing diagrams of 5 and 6 are shown in Figures 2
and 3, respectively.
Melting points were determined with an X-4 digital microscope
melting-point apparatus Beijing Tech. Instrument Co., LTD.
(Beijing, China) and are uncorrected. UV–vis spectra were recorded
on a Perkin–Elmer Lambda 35 spectrophotometer at room tem-
perature in methanol solution. FTIR spectra were recorded on a
Nicolet 380 FTIR instrument using KBr disks in the range of
4000–400 cmꢂ1 1H-NMR spectra were measured on a Bruker
.
AM 500MHz spectrometer at ambient temperature in CDCl3.
Chemical shifts are reported in parts per million (ppm) downfield
from TMS. Electrospray ionization mass spectrum (ESI-MS) was
recorded with an LCQ ADVANTAGE MAX mass spectrometer,
with MeOH on the mobile phase; the flow rate of the mobile phase
was 0.2 cm3 minꢂ1. The spray voltage, the capillary voltage, and the
capillary temperature were 4 kV, 40 V, and 260ꢀC, respectively.
Elemental analyses (C, H, N) were carried out with a Thermo
Finnigan Flash 1112A elemental analyzer. All chemicals used were
of analytical grade and without further purification unless otherwise
stated. Toluene was freshly distilled from Na/benzophenone,
whereas pyridine was distilled over NaOH.
Ethyl quinoline-2-carboxylic acid (1).
Ninety-eight percent
concentrated sulfuric acid (12 mL) was added dropwise to a
solution of quinoline-2-carboxylic acid (17.3 g, 100 mmol) in
5
6
Figure 1. Views of 5 and 6 showing the atom-numbering scheme. Thermal ellipsoids are shown at the 50% probability level. Hydrogen atoms and solvent
molecules are omitted for clarity.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

Month 2013
Syntheses, Crystal Structures, and Spectral Characterization of
Two Novel Quinolyl Substituted Triazoles
Table 1
(30 mL) surrounded by an ice-water bath. The solution was
Selected bond lengths (Å) and angles (ꢀ) for 5 and 6ꢁ0.25(Me2CO).
stirred for 8 h at ambient temperature and poured into 50 mL
water; the precipitate was filtered, and the resulting solid was
recrystallized from anhydrous ethanol to give 3 as white solids
(2.5 g, 78.3%), mp 208–210 ꢀC. FTIR (n, cmꢂ1): 3246, 3025,
2963, 1699, 1646, 1609, 1567, 1507, 1470, 1302, 1260, 1026,
926, 848.
5
6ꢁ0.25(Me2CO)
N1–C5
N2–N3
N4–N5
O1–C18
1.371 (2)
1.370 (2)
1.410 (2)
1.421 (3)
N1–C5
N2–N3
N4–C19
O1–C18
1.372 (3)
1.377 (3)
1.441 (3)
1.443 (3)
1,4-Dichloro-1-(2-quinolyl)-4-(p-methoxyphenyl)-2,3-diaza-
1,3-butadiene (4).
A solution of thionyl chloride (3 mL,
C10–N2–N3
C10–C9–N1
C10–N4–C11
C16–C15–O1
107.5 (2)
C10–N2–N3
C10–C9–N1
C10–N4–C11
C16–C15–O1
107.2 (2)
40 mmol) in anhydrous toluene (10 mL) was added dropwise to
a stirring solution of 3 (2.5 g, 8 mmol) in anhydrous toluene
(30 mL). The solution was refluxed for 12 h at 120 ꢀC, and the
solvent was removed under reduced pressure. The precipitate
was filtered, and the resulting solid was recrystallized from
anhydrous toluene to give 4 as white solids (2.1 g, 73.5%), mp
199–200 ꢀC. FTIR (n, cmꢂ1): 3433, 1612, 1598, 1497, 1266,
1177, 1086, 1020, 834, 762.
118.8 (2)
106.1 (2)
124.8 (2)
117.0 (2)
105.0 (2)
124.2 (3)
Table 2
The dihedral angles (ꢀ) for 5 and 6ꢁ0.25(Me2CO).
3-(p-Methoxyphenyl)-4-amino-5-(2-quinolyl)-1,2,4-triazole (5).
A mixture of 4 (0.72g, 2 mmol) and anhydrous hydrazine (3mL,
6 mmol) was sealed in a 25-mL capacity Teflon-lined stainless-
steel reactor and heated for 4 h at 120 ꢀC. The solution was
cooled to ambient temperature at a rate of 5 ꢀC/h. The precipitate
was filtered and washed with deionized water, and the resulting
solid was recrystallized from acetone to give 5 as colorless
crystals (0.47g, 74.2%), mp 212–213 ꢀC. UV–vis (MeOH, nm):
277 (0.29), 325 (0.20), 338 (0.20). FTIR (n, cmꢂ1): 3432, 1609,
1596, 1496, 1466, 1450, 1437, 1285, 1255, 1177, 1048, 1031,
838, 774. 1H-NMR (CDCl3/500MHz), d (ppm): 8.50–8.51 (d,
1H, QH), 8.35–8.37 (d, 1H, QH), 8.28–8.30 (d, 2H, ArH), 8.11–
8.13 (d, 1H, QH), 7.91–7.93 (d, 1H, QH), 7.80–7.83 (m, 1H,
QH), 7.64–7.67 (m, 1H, QH), 7.06–7.08 (d, 2H, ArH), 3.92 (s,
3H, CH3) [23]. ESI-MS: m/z 318.3 (M + H)+. Anal. Calcd. for
C18H15N5O: C, 68.13; H, 4.76; N, 22.07. Found: C, 68.27; H,
4.94; N, 22.17.
3-(p-Methoxyphenyl)-4-phenyl-5-(2-quinolyl)-1,2,4-triazole (6).
A mixture of 4 (0.72 g, 2 mmol) and aniline (20 mL) was
refluxed for 3 h at 190 ꢀC under argon atmosphere; the
excess aniline was removed under reduced pressure. The
residue was recrystallized from acetone to give 6ꢁ0.25
(Me2CO) as colorless crystals (0.60 g, 78.8%), mp 219–
220 ꢀC. UV–vis (MeOH, nm): 275 (0.34), 321 (0.19).
FTIR (n, cmꢂ1): 3433, 1611, 1597, 1496, 1471, 1457,
1256, 1178, 1032, 835, 773, 756. 1H-NMR (CDCl3/
500 MHz), d (ppm): 8.40–8.41 (d, 1H, QH), 8.23–8.25 (d,
1H, QH), 7.80–7.81 (d, 1H, QH), 7.58–7.61 (m, 1H, QH),
7.43–7.56 (m, 7H, ArH), 7.36–7.38 (d, 2H, QH), 6.85–6.87
Compounds
Quinolyl/Trz
Ph/Trz
CH3O-Ph/Trz
5
6
6.4 (2)
23.3 (7)
5.6 (7)
32.4 (8)
68.2 (8)
anhydrous ethanol (120 mL) surrounded by an ice-water bath, then
the solution was refluxed for 24 h. Upon cooling to ambient
temperature, the product was poured into 100 mL water. The
resulting solution was neutralized to pH = 7–8 with a solution of
potassium carbonate. The precipitate was filtered, and the filtrate
was extracted with ether (5 ꢃ 60 mL). After drying over magnesium
sulfate, the organic phase was evaporated to dryness. The
unpurified ester can be used in the next hydrazinolysis.
2-Quinolylhydrazine (2).
A mixture of 1, 85% hydrazine
hydrate (11.8 mL, 200 mmol), and anhydrous ethanol (50 mL)
was refluxed for 8 h. The solvent was removed under reduced
pressure, and the remainder was washed by petroleum ether; the
precipitate was filtered, and the resulting solid was recrystallized
from anhydrous ethanol to give 2 as white solids (9.6 g, 51.4%
for a two-step reaction), mp 135–137 ꢀC (lit. mp 137–139 ꢀC)
[26]; FTIR (n, cmꢂ1): 3294, 3201, 3053, 1662, 1622, 1594,
1519, 1500, 1426, 982, 952.
N-(p-Methoxyphenylcarbonyl)-N0-(2-quinolinecarbonyl)
hydrazine (3).
12 mmol) in anhydrous pyridine (10 mL) was added dropwise to
a stirring solution of 2 (1.87 g, 10 mmol) in anhydrous pyridine
A solution of anisoyl chloride (1.6 mL,
Table 3
The hydrogen bonds in 5 and 6ꢁ0.25(Me2CO).
Compounds
D–HꢁꢁꢁA
d(D–H)/Å
d(HꢁꢁꢁA)/Å
d(DꢁꢁꢁA)/Å
∠D–HꢁꢁꢁA/ꢀ
5
C4–H4AꢁꢁꢁO1i
0.93
0.93
0.93
0.93
0.93
0.86
0.93
0.93
2.86
2.59
2.67
2.37
2.96
2.32
2.67
2.83
3.674 (3)
3.504 (3)
3.428 (3)
3.021 (3)
3.748 (3)
2.889 (2)
3.377 (4)
3.436 (4)
148
168
139
127
144
123
133
124
C16–H16AꢁꢁꢁN2ii
C16–H16AꢁꢁꢁN3ii
C17–H17AꢁꢁꢁN5
C13–H13AꢁꢁꢁN1iii
N5–H5BꢁꢁꢁN1
6
C1–H1AꢁꢁꢁO1iv
N23–H23AꢁꢁꢁN2v
Symmetry codes: (i) ꢂ1 ꢂ x, 1/2 + y, 1/2 ꢂ z; (ii) ꢂ1 ꢂ x, y ꢂ 1/2, 1/2 ꢂ z; (iii) ꢂx, 1/2 + y, 1/2 ꢂ z; (iv) x ꢂ 2, 3/2 ꢂ y, z ꢂ 1/2; (v) x, 3/2 ꢂ y, 1/2 + z.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

G-P. Shen, J-J. Jiang, F. Sun, X. Shen, D-R. Zhu, and X-Q. Liu
Vol 000
Table 4
The C–Hꢁꢁꢁp interactions in 5 and 6ꢁ0.25(Me2CO).
Compounds
D–HꢁꢁꢁA
d(D–H)/Å
d(HꢁꢁꢁA)/Å
d(DꢁꢁꢁA)/Å
∠D–HꢁꢁꢁA/ꢀ
5
C14–H14Aꢁꢁꢁpi
C16–H16Aꢁꢁꢁpii
C18–H18Cꢁꢁꢁpiii
C13–H13Aꢁꢁꢁp
0.93
0.93
0.96
0.93
3.10
3.04
2.75
2.96
3.980 (2)
3.883 (2)
3.546 (2)
3.666 (3)
158
152
141
134
6
Symmetry codes: (i) ꢂx, 1/2 + y, 1/2 ꢂ z; (ii) 1 ꢂ x, y ꢂ 1/2, 1/2 ꢂ z; (iii) 1 + x, y, z.
Figure 2. View of the crystal packing for 5 showing hydrogen bonds and C–Hꢁꢁꢁp interactions. [Color figure can be viewed in the online issue, which is
available at www.interscience.wiley.com.]
Figure 3. View of the crystal packing for 6 showing hydrogen bonds and C–Hꢁꢁꢁp interactions. [Color figure can be viewed in the online issue, which is
available at www.interscience.wiley.com.]
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

Month 2013
Syntheses, Crystal Structures, and Spectral Characterization of
Two Novel Quinolyl Substituted Triazoles
Table 5
Crystallographic data for 5 and 6ꢁ0.25(Me2CO).
Compounds
5
6ꢁ0.25(Me2CO)
Empirical formula
Formula weight
Crystal system
Space group
a (Å)
C
18H15N5O
317.35
C24.75 H19.50N4O1.25
392.94
Monoclinic
P21/c
Monoclinic
P21/c
5.1799 (8)
10.6489 (15)
27.849 (4)
94.364 (2)
1531.7 (4)
4
6.0042 (16)
22.324 (6)
16.629 (4)
97.176 (4)
2211.4 (10)
4
1.180
0.075
824
b (Å)
c (Å)
b (ꢀ)
V (Å3)
Z
Dc (g∙cmꢂ3
)
1.376
0.091
664
m (mmꢂ1
F (000)
)
Crystal size (mm)
θ range
0.22 ꢃ 0.16 ꢃ 0.12
1.47–25.00
10,005
2686 [Rint = 0.0260]
2239
2686/0/217
1.072
0.0460/0.1328
0.0546/0.1382
0.488, ꢂ0.518
0.22 ꢃ 0.14 ꢃ 0.10
1.82–25.00
15,516
3875 [Rint = 0.0819]
1809
3875/78/289
1.413
0.0742/0.1780
0.1604/0.1926
0.395, ꢂ0.199
Reflections collected
Independent reflections
Reflections observed [I > 2s(I)]
Data/restraints/parameters
Goodness of fit on F2
R/wR [I > 2s(I)]
R/wR (all data)
Max., Min. Δr (eꢁÅꢂ3
)
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(M + H)+. Anal. Calcd. for C24H18N4O: C, 76.17; H, 4.79;
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Single-crystal X-ray diffraction analysis of 5 and 6ꢁ0.25
(Me2CO).
The well-shaped single crystals of 5 and 6ꢁ0.25
(Me2CO) were selected for lattice parameter determination and
collection of intensity data at 296 K on a Bruker SMART CCD
diffractometer with a detector distance of 5 cm and frame
exposure time of 10 s using a graphite-monochromated Mo Ka
(l = 0.71073 Å) radiation. The structures were all solved by
direct methods and refined on F2 by full-matrix least-squares
procedures using SHELXTL software [27]. All non-hydrogen
atoms were anisotropically refined. All H atoms were located
from a difference map and refined isotropically. Atoms C25,
C26, C27, and O2 of the acetone of 6ꢁ0.25(Me2CO) are
disordered, and their occupation factors are 0.25. Details on
crystal data of 5 and 6ꢁ0.25(Me2CO) are summarized in Table 5.
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CCDC 849328 (5) and 849329 (6) contain the supplementary
crystallographic data for this article. These data can be obtained
free of charge from the Cambridge Crystallographic Data Centre
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Acknowledgment. This work was funded by the National Natural
Science Foundation of China (No. 20771059, 21171093, and
20976082) and the State Key Laboratory of Materials-Oriented
Chemical Engineering (KL11-03).
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Journal of Heterocyclic Chemistry
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