Synthesis and anti-inflammatory activity evaluation of novel 3-alkyl-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo[e][1,3]oxazine derivatives

Article abstract of DOI:10.1007/s00044-016-1679-7

To discover new compounds with anti-inflammatory activity, a series of novel 3-alkyl-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo[e][1,3]oxazine derivatives were synthesized and their structures were confirmed by spectroscopic techniques. In vivo anti-inflammatory activity of the synthesized compounds was determined using the xylene-induced mouse ear edema model. 3-Heptyl-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo[e] [1,3]oxazine and 3-p-tolyl-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo[e][1,3]oxazine demonstrated higher anti-inflammatory activity (74.04 % and 64.99 %, respectively) at 0.5 h after intraperitoneal administration than the reference drug ibuprofen (62.65 %). Further, the time of peak effect after oral administration was 4 h for both compounds. Our results identify new compounds with anti-inflammatory activity in vivo that may have improved safety/side effect profiles relative to the currently approved nonsteroidal anti-inflammatory drugs.

Full text of DOI:10.1007/s00044-016-1679-7

MEDICINAL
CHEMISTRY
RESEARCH
Med Chem Res
DOI 10.1007/s00044-016-1679-7
ORIGINAL RESEARCH
Synthesis and anti-inflammatory activity evaluation of novel 3-alkyl-6-
(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo[e][1,3]oxazine derivatives
Yan-Fei Li1 Hong-Jian Zhang1 Zhe-Shan Quan1
●
●
Received: 15 January 2016 / Accepted: 6 July 2016
© Springer Science+Business Media New York 2016
Abstract To discover new compounds with anti-
inflammatory activity, a series of novel 3-alkyl-6-(4H-
1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo[e][1,3]oxazine
derivatives were synthesized and their structures were
confirmed by spectroscopic techniques. In vivo anti-
inflammatory activity of the synthesized compounds was
determined using the xylene-induced mouse ear edema
model. 3-Heptyl-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-
benzo[e] [1,3]oxazine and 3-p-tolyl-6-(4H-1,2,4-triazol-4-
Introduction
Inflammation is part of the complex biological reaction
in vascular tissues to protect from injury or harmful
stimuli including pathogens, damaged cells, or irritation
(Ferrero-Miliani et al., 2007). However, prolonged
inflammation can cause serious diseases such as diabetes,
cancer, and atherosclerosis (Lyman et al., 2014; Momi et al.,
2012). Nonsteroidal anti-inflammatory drugs (NSAIDs) are
currently the most commonly administered medicines to
reduce acute and chronic inflammation (Sng and Schug,
2009), fever (Eccles, 2006), and pain (Zahradnik et al., 2010;
Kraemer and Rose, 2009). Recently, many studies have
shown that long-term oral administration of NSAIDs is fre-
quently associated with gastrointestinal (Botting, 2006;
Naesdal and Brown, 2006; Cryer, 2005; Lazzaroni and
Bianchi, 2004; James and Hawkey, 2003), hepatic (Adebayo
and Bjarnason, 2006), and renal (Schneider et al., 2006;
Mounier et al., 2006) side effects in patients. Therefore, the
discovery of new compounds with enhanced safety profiles
remains an area of unmet medical need.
yl)-3,4-dihydro-2H-benzo[e][1,3]oxazine
demonstrated
higher anti-inflammatory activity (74.04 % and 64.99 %,
respectively) at 0.5 h after intraperitoneal administration
than the reference drug ibuprofen (62.65 %). Further, the
time of peak effect after oral administration was 4 h for both
compounds. Our results identify new compounds with anti-
inflammatory activity in vivo that may have improved
safety/side effect profiles relative to the currently approved
nonsteroidal anti-inflammatory drugs.
●
●
Keywords Synthesis Anti-inflammatory Mannich
●
reaction 4-Aminophenol
Literature reports suggest that 1,2,4-triazoles exhibit a
wide spectrum of therapeutic properties, including anti-
bacterial (Demirbas et al., 2005; Sharma et al., 2008; Turan-
Zitouni et al., 2005), antiviral (Kritsanida et al., 2002;
Abdel-Aal et al., 2008), analgesic (Turan-Zitouni et al.,
2001), anti-inflammatory (Tozkoparan et al., 2007; Rabea
et al., 2006; Labanauskas et al., 2004), anticonvulsant
(Almasirad et al., 2004; Kucukguzel et al., 2004), anti-
depressant (Varvaresou et al., 1998), and anticancer (Holla
et al., 2003; Duran et al., 2002). Further, derivatives con-
taining oxazine also exhibit anti-mycobacterial (Sindhu
et al., 2014), anticancer (Kalirajan et al., 2012), anti-
inflammatory (Liu et al., 2010), antimicrobial, and anti-
fungal (EI Azab et al., 2015) activities.
Electronic supplementary material The online version of this article
(doi:10.1007/s00044-016-1679-7) contains supplementary material,
which is available to authorized users.
* Zhe-Shan Quan
zsquan@ybu.edu.cn
1
Key Laboratory of Natural Resources and Functional Molecules of
the Changbai Mountain, Affiliated Ministry of Education, College
of Pharmacy, Yanbian University, Yanji, Jilin 133002, China

Med Chem Res
In this study, we designed and synthesized 3-alkyl-6-
(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo[e][1,3]oxa-
zine derivatives (Fig. 1) and evaluated their anti-
inflammatory activity in a xylene-induced mouse ear
edema model of inflammation.
min, and then 4-aminophenol was added to the mixture to
obtain compound 1, which was catalyzed by ice water.
Structures of all synthesized compounds were confirmed by
infrared (IR), proton nuclear magnetic resonance (1H-
NMR), 13C-NMR and high resolution-mass spectrometry
(HRMS) techniques.
Pharmacology
Results and discussion
Chemistry
Xylene-induced ear edema in kunming mice is a reliable
model to evaluate the in vivo anti-inflammatory activity of
test compounds (Sowemimo et al., 2013; Da Silva et al.,
2010). ibuprofen was used as a reference drug. As a primary
screen, the anti-inflammatory activity for each of the newly
synthesized compounds was evaluated at a dose of 100 mg/kg
administered by intraperitoneal injection. Since most anti-
inflammatory medications are administered orally in the
clinical setting, we chose two of the compounds with the
highest anti-inflammatory activity in the primary screen (2d,
2h) for further assessment by oral (p.o.) administration.
Compounds 2d and 2h were administered at multiple time
points (1, 2, 3, 4, 5, and 6 h) prior to xylene application. The
time of peak anti-inflammatory effect for compounds 2d
and 2h was 4 h after p.o. administration.
Target compounds 2a–y were prepared by a two-step
synthesis (Scheme 1). In the first step, compound 1 was
prepared by the Michael method (Stocks et al., 2004):
dimethylformamide dimethylacetal (DMF-DMA) and for-
mohydrazide were reacted in acetonitrile at 50 °C for 30
In the primary screen, all of the synthesized compounds
were administrated intraperitoneally to assess their anti-
inflammatory activity in the xylene-induced mouse ear
edema model. Anti-inflammatory activity was expressed as
the inhibition percentage compared to the control group. As
shown in Table 1, most compounds exhibited some degree
Fig. 1 Structure of compounds 1, 2, and 2a–y
H
N
H
O
O
O
50 oC,30min
CH3CN
N
N
N
+
O
H
NHNH2
O
HO
R-NH2, HCHO
100oC,48h
CH3COOH
120oC,10h
N
R
N
N
N
N
N
N
HO
2a-2y
1
NH2
R:
2a -C4H9
2b -C5H11
2c -C6H11
2d -C7H15
2e -C8H17
2f -C12H23
2g -C6H5
2h -C6H4(p-CH3)
2i -C6H4(p-OCH3)
2j -C6H4(o-F)
2o -CH2C6H5
2v -CH2C6H4(m-Cl)
2w -CH2C6H4(p-Cl)
2x -CH2C6H4(o-Br)
2y -CH2C6H4(p-Br)
2p -CH2C6H4(p-CH3)
2q -CH2C6H4(p-OCH3)
2r -CH2C6H4(m-F)
2s -CH2C6H4(p-F)
2k -C6H4(m-F)
2l -C6H4(p-F)
2m -C6H4(m-Cl)
2n -C6H4(p-Br)
2t -CH2C6H4(2,4-2F)
2u -CH2C6H4(o-Cl)
Scheme 1 Synthesis of the target compounds 2a-2y

Med Chem Res
Table 1 Anti-inflammatory activity of compounds 2a–y after
intraperitoneal administration (n = 8)
the xylene-induced ear edema assay. As the carbon chain
lengthened, the anti-inflammatory activity of tested com-
pounds first increased and then decreased, suggesting that
C-7 is the appropriate length of the alkyl chain, and that
appropriate lipophilic property is essential to the anti-
inflammatory activity of the compounds (Li et al., 2009;
Kroll et al., 1998).
For aromatic ring-substituted derivatives, electron-
donating groups seemed to be a more beneficial structural
feature than electron-withdrawing groups for anti-
inflammatory activity. For compounds 2g–n, the order of
activity for different electron-withdrawing substituents was
m-F > p-F > p-Br (>o-F > m-Cl), while the order of activity
for electron-donating substituents was p-CH3 > p-OCH3.
For compounds 2o–y, the order of activity for electron-
withdrawing substituents was m-Cl > p-F > p-Cl> 2,4-2F >
o-Br (>m-F > o-Cl > p-Br), and the order of activity for
electron-donating substituents was p-CH3 > p-OCH3. In
addition, comparing compounds 2g-n with compounds
2o–y suggested that differences existed for compounds
substituted at the phenyl ring; however, an all-inclusive rule
for the effect of phenyl ring substitutions on anti-
inflammatory activity was not clear.
Comp.
R
Dose
Edema mean
Inhibition
Rate(%)
(mg/kg) Mean S.E.M.
(mg)
2a
2b
2c
2d
2e
2f
–C4H9
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
5.03 1.53**
3.85 0.52***
3.82 1.05***
2.58 1.05***
3.87 0.63***
4.25 1.55***
5.58 3.48*
3.48 1.31***
4.68 2.24**
6.65 1.15
4.07 1.58***
4.33 1.90***
6.92 2.42
5.12 1.32**
3.90 1.13***
3.73 1.42***
49.41
61.31
61.64
74.04
61.14
57.29
43.89
64.99
52.93
33.17
59.13
56.45
30.49
48.58
60.80
62.56
–C5H11
–C6H13
–C7H15
–C8H17
–C12H23
2g
2h
2i
–C6H5
–C6H4(p-CH3)
–C6H4(p-OCH3)
–C6H4(o-F)
–C6H4(m-F)
–C6H4(p-F)
–C6H4(m-Cl)
–C6H4(p-Br)
–CH2C6H5
2j
2k
2l
2m
2n
2o
2p
–CH2C6H4(p-
CH3)
2q
–CH2C6H4(p-
OCH3)
100
6.75 1.87
32.16
2r
2s
2t
–CH2C6H4(m-F)
–CH2C6H4(p-F)
100
100
100
6.18 2.75
37.86
55.61
49.41
Based on the results from our primary screen, com-
pounds 2d and 2h were chosen to be further evaluated at
multiple time points after oral administration (1, 2, 3, 4, 5,
and 6 h). As shown in Table 2, the anti-inflammatory effects
of 2d, 2h, and ibuprofen first increased and then declined
over this time period. The time of peak effect was 4 h for all
three compounds. Moreover, derivative 2d showed higher
activity than the reference drug at all time points.
4.42 1.96**
5.03 2.20**
–CH2C6H4(2,4-
2F)
2u
–CH2C6H4(o-Cl) 100
–CH2C6H4(m-Cl) 100
–CH2C6H4(p-Cl) 100
–CH2C6H4(o-Br) 100
–CH2C6H4(p-Br) 100
6.87 1.63
30.99
55.95
53.94
44.39
25.96
–
2v
4.38 2.41**
4.58 0.99**
5.53 0.73*
7.37 2.34
2w
2x
2y
DMSO
Ibuprofen
—
—
100
100
9.95 0.58
3.72 0.75***
62.65
Experimental
— No anti-inflammatory activity
*0.01 <p < 0.05, **p < 0.01, ***p < 0.001 compared to the vehicle
group at corresponding time
Chemistry
Reactions were monitored by thin-layer chromatography on
silica gel plates precoated with F254 gel. Developed plates
of anti-inflammatory activity when administered intraper-
itoneally. Compounds 2d and 2h showed the highest inhi-
bition percentage, 74.04 % and 64.99 %, respectively, and
outperformed the reference drug ibuprofen in the assay
(62.65 %). Among the tested compounds, compounds 2a,
2f, 2i, 2n, 2s, 2t, and 2v–x showed 5–20 % anti-
inflammatory activity compared to the control group.
However, their anti-inflammatory activities were lower than
that of ibuprofen. Compounds 2b, 2c, 2e, 2f, 2k, 2l, 2o, and
2p were not significantly different from ibuprofen. The
remaining compounds did not exhibit significant differences
compared to vehicle.
Table 2 Anti-inflammatory activity of compounds 2d and 2h
administered o.p. at different times before xylene application
Time (h)
Dose (mg/kg)
Inhibition
2d
2h
Ibuprofen
1
2
3
4
5
6
100
100
100
100
100
100
18.05
31.56
33.90
38.70
52.34*
36.75
29.87
10.26
24.03
44.68*
56.63**
15.71
9.22
49.48*
68.57***
80.52***
62.73**
53.64**
Most of the alkyl chain-substituted derivatives investi-
gated exhibited at least modest anti-inflammatory activity in
*0.01 < p < 0.05, **p < 0.01, ***p < 0.001 compared to the vehicle
group at corresponding dose

Med Chem Res
were examined under an ultraviolet lamp (254 nm). Melting
points were determined in open capillary tubes and were
uncorrected. IR spectra were recorded (in KBr) using an
fourier transform infrared spectroscopy1730 Spectrometer
(PerkinElmer, Waltham, MA, USA). 1H-NMR and 13C-
NMR spectra were recorded using an AV-300 Spectrometer
(Bruker Daltonik, Bremen, Germany), and all chemical
shifts were described in parts per million relative to that of
tetramethylsilane. High-resolution mass spectra were mea-
sured using a matrix-assisted laser desorption/ionization-
time of flight (MALDI-TOF) mass spectrometer (Bruker
Daltonik, Germany). Chemicals were purchased from
Aldrich Chemical Corporation.
(CDCl3, 300 MHz) δ: 0.94 (t, 3H, J = 7.2 Hz, –CH3),
1.31–1.43 (m, 2H, –CH2–), 1.51–1.61 (m, 2H, –CH2–),
2.75(t, 2H, J = 6.0 Hz, –CH2–), 4.05 (s, 2H, –N–CH2–Ar),
4.93 (s, 2H, –O–CH2–N–), 6.90 (d, 1H, J = 8.6 Hz, Ar–H),
7.00 (s, 1H, Ar–H), 7.13 (d, 1H, J = 6.7 Hz, Ar–H), 8.38 (s,
2H, Triazole-H). 13C-NMR (CDCl3, 75 MHz) δ: 13.93,
20.28, 30.13, 49.97, 51.17, 82.98, 117.90, 121.97, 122.22,
126.37, 141.83, 154.96. IR (KBr) cm−1: 1525 (C=N), 1223,
1092 (C–O–C). ESI-HRMS calcd. for C14H19N4O+ ([M +
H]+): 259.1553; found: 259.1560.
3-Pentyl-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo[e]
[1,3]oxazine (2b) M.p. 129–130 °C, yield: 36 %. 1H-NMR
(CDCl3, 300 MHz) δ: 0.92 (t, 3H, J = 6.0 Hz, –CH3),
1.31–1.39 (m, 4H, –CH2–), 1.53–1.64 (m, 2H, –CH2–),
2.75 (t, 2H, J = 7.5 Hz, –CH2–), 4.06 (s, 2H, –N–CH2–Ar),
4.94 (s, 2H, –O–CH2–N–), 6.91 (d, 1H, J = 8.7 Hz, Ar–H),
7.00 (s, 1H, Ar–H), 7.13 (dd, 1H, J1 = 3.0 Hz, J2 = 6.0 Hz,
Ar–H), 8.38 (s, 2H, Triazole-H). 13C-NMR (CDCl3, 75
MHz) δ: 14.02, 22.50, 27.70, 29.26, 49.95, 51.43, 82.95,
117.87, 121.96, 122.17, 126.36, 141.81, 154.93. IR (KBr)
cm−1: 1528 (C=N), 1200, 1093 (C–O–C). ESI-HRMS
calcd. for C15H21N4O+ ([M + H]+): 273.1710; found:
273.1706.
General procedure for the synthesis of compound 1
(Deng et al., 2014) Dimethoxy-N,N-dimethylmethanamine
(DMF-DMA; 6.5 g, 55 mmol) was added to a solution of
3.3 g (55 mmol) formohydrazide in acetonitrile (30 ml) in a
100 ml round-bottomed flask equipped with a reflux
condenser. The reaction mixture was warmed to 50 °C for
30 min and then 5.5 g (50 mmol) of 4-aminophenol in
acetonitrile (10 ml) was added with 5 ml acetic acid. The
reaction temperature was increased to 120 °C for 9 h. After
being cooled and concentrated, the product was added to ice
water. The precipitate was collected via filtration and
vacuum dried to produce the product at a moderate yield.
The average of the yield was shown in the text.
3-Hexyl-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo[e]
[1,3]oxazine (2c) M.p. 131–133 °C, yield: 32 %. 1H-NMR
(CDCl3, 300 MHz) δ: 0.89 (t, 3H, J = 6.7 Hz, –CH3),
1.27–1.39 (m, 6H, –CH2–), 1.52–1.61 (m, 2H, –CH2–),
2.74 (t, 2H, J = 7.5 Hz, –CH2–), 4.05 (s, 2H, –N–CH2–Ar),
4.93 (s, 2H, –O–CH2–N–), 6.90 (d, 1H, J = 8.7 Hz, Ar-H),
7.00 (s, 1H, Ar–H), 7.13 (dd, 1H, J1 = 2.5 Hz, J2 = 8.6 Hz,
Ar–H), 8.38 (s, 2H, Triazole-H). 13C-NMR (CDCl3, 75
MHz) δ: 14.03, 22.59, 26.80, 27.98, 31.65, 49.94, 50.24,
51.46, 82.94, 117.87, 121.96, 122.17, 126.35, 141.81,
154.92. IR (KBr) cm−1: 1531 (C=N), 1223, 1095 (C–O–C).
ESI-HRMS calcd. for C16H23N4O+ ([M + H]+): 287.1866;
found: 287.1881.
4-(4H-1,2,4-Triazol-4-yl)phenol(1) M.p.
288–290 °C,
1
yield: 76 %. H-NMR (dimethyl sulfoxide (DMSO), 300
MHz) δ: 6.90 (d, 2H, J = 8.5 Hz, Ar–H), 7.46 (d, 2H, J =
8.5 Hz, Ar–H), 8.96 (s, 2H, J = 7.5 Hz, Triazole-H), 9.92 (s,
1H, –OH).
General procedure for the synthesis of compounds 2a–y
(Wen et al., 2015) Formaldehyde (18 mmol) was added to
a solution of 6 mmol amine in 20 ml ethanol in a 50 ml
round-bottomed flask. Compound 1 (1.0 g, 6 mmol) was
added portion-wise to the mixture over 15 min with stirring
at 0 °C, followed by addition of 1 ml triethylamine as a
catalyst. The temperature of the mixture was gradually
increased to 100 °C and stirred at 100 °C for 48 h. The
reaction mixture was concentrated under reduced pressure,
diluted with 30 ml dichloromethane, washed with 30 ml
(1 mol/L) sodium hydroxide and 30 ml distilled water, and
then saturated with 30 ml sodium chloride. The combined
organic extracts were dried over anhydrous sodium sulfate,
filtered, and concentrated under reduced pressure to afford
brown oil. The oil was purified on a silica gel column with
methanol and dichloromethane [V(methanol):V(dichlor-
omethane) = 1:50] and collected as eluent fractions to yield
target compounds 2a–y.
3-Heptyl-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo
1
[e][1,3]oxazine (2d) M.p. 129–131 °C, yield: 28 %. H-
NMR (CDCl3, 300 MHz) δ: 0.89 (t, 3H, J = 6.7 Hz, –CH3),
1.31 (s, 10H, –CH2–), 2.75 (t, 2H, J = 7.5 Hz, –CH2–), 4.05
(s, 2H, –N–CH2–Ar), 4.94 (s, 2H, –O–CH2–N–), 6.91
(d,1H, J = 8.7 Hz, Ar–H), 7.00 (s, 1H, Ar–H), 7.13 (d, 1H,
J = 6.0 Hz, Ar-H), 8.39 (s, 2H, Triazole-H). 13C-NMR
(CDCl3, 75 MHz) δ: 14.07, 22.61, 27.10, 28.04, 29.13,
31.79, 49.97, 51.48, 82.97, 117.91, 121.97, 122.22, 126.36,
141.83, 154.96. IR (KBr) cm−1:1531 (C=N), 1232, 1095
(C–O–C). ESI-HRMS calcd for C17H25N4O+ ([M + H]+):
301.2023; found: 301.2020.
3-Octyl-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo[e]
[1,3]oxazine (2e) M.p. 130–132 °C, yield: 31 %. 1H-NMR
(CDCl3, 300 MHz) δ: 0.88 (t, 3H, J1 = 6.0 Hz, -CH3),
3-Butyl-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo[e]
[1,3]oxazine (2a) M.p. 111–112 °C, yield: 34 %. 1H-NMR

Med Chem Res
1.27–1.32 (m, 12H, –CH2–), 2.75 (t, 2H, J1 = 7.5 Hz,
–CH2–), 4.05 (s, 2H, –N–CH2–Ar), 4.94 (s, 2H,
–O–CH2–N–), 6.91 (d, 1H, J = 8.7 Hz, Ar–H), 7.00 (d, 1H,
J = 3.0 Hz, Ar–H), 7.13 (dd, 1H, J1 = 3.0 Hz, J2 = 9.0 Hz,
Ar–H), 8.39 (s, 2H, Triazole-H). 13C-NMR (CDCl3, 75
MHz) δ: 14.08, 22.63, 27.15, 28.05, 29.25, 29.43, 31.80,
49.97, 51.48, 82.98, 117.90, 121.97, 122.21, 126.37,
141.82, 154.97. IR (KBr) cm−1: 1524 (C=N), 1223, 1091
(C–O–C). ESI-HRMS calcd for C18H27N4O+ ([M + H]+):
315.2179; found: 315.2186.
55.50, 81.12, 114.61, 118.46, 120.96, 121.26, 122.51,
126.63, 141.82, 154.95, 155.40. IR (KBr) cm−1: 1512
(C=N), 1241, 1085 (C–O), 1187 (C–N). ESI-HRMS calcd.
for C17H17N4O2 ([M + H]+): 309.1346; found: 309.1346.
+
3-(2-Fluorophenyl)-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-
2H-benzo[e][1,3]oxazine (2j) M.p. 153–154 °C, yield:
16 %. 1H-NMR (CDCl3, 300 MHz) δ: 4.65 (s, 2H,
–N–CH2–Ar), 5.38 (s, 2H, –O–CH2–N–), 6.97–7.25 (m,
7H, Ar–H), 8.39 (s, 2H, Triazole-H). 13C-NMR (CDCl3, 75
MHz) δ: 50.47, 80.59, 116.36, 116.63, 118.57, 121.22,
122.33, 122.58, 124.51, 124.61, 126.86, 136.17, 136.29,
141.80, 154.50. IR (KBr) cm−1: 1523 (C=N), 1230,
1082 (C–O–C), 1183 (C–N). ESI-HRMS calcd. for
C16H14FN4O+ ([M + H]+): 297.1146; found: 297.1152.
3-Dodecyl-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo
[e][1,3]oxazine (2f) M.p. 116–117 °C, yield: 29 %. 1H-
NMR (CDCl3, 300 MHz) δ: 0.89 (t, 3H, J1 = 6.0 Hz, –CH3),
1.27 (s, 18H, –CH2–), 1.52–1.63 (m, 2H, –CH2–), 2.75(t,
2H, J = 7.5 Hz, –CH2–), 4.05 (s, 2H, –N–CH2–Ar), 4.94 (s,
2H, –O–CH2–N–), 6.91 (d, 1H, J = 8.7 Hz, Ar–H), 6.99 (d,
1H, J = 3.0 Hz, Ar–H), 7.13 (dd, 1H, J1 = 3.0 Hz, J2 = 9.0
Hz, Ar–H), 8.38 (s, 2H, Triazole-H). 13C-NMR (CDCl3, 75
MHz) δ: 14.10, 22.66, 27.15, 28.05, 29.32, 29.48, 29.60,
31.89, 49.98, 51.49, 82.97, 117.89, 121.96, 122.20, 126.37,
141.81, 154.96. IR (KBr) cm−1: 1519 (C=N), 1226, 1093
(C–O–C). ESI-HRMS calcd. for C22H35N4O+ ([M + H]+):
371.2805; found: 371.2808.
3-(3-Fluorophenyl)-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-
2H-benzo[e][1,3]oxazine (2k) M.p. 164–165 °C, yield:
20 %. 1H-NMR (CDCl3, 300 MHz) δ: 4.70 (s, 2H,
–N–CH2–Ar), 5.41 (s, 2H, –O–CH2–N–), 6.65–7.25 (m,
7H, Ar–H), 8.38 (s, 2H, Triazole-H). 13C-NMR (CDCl3, 75
MHz) δ: 50.54, 79.39, 105.43, 105.76, 108.56, 108.84,
113.81, 118.71, 121.25, 122.15, 122.70, 126.94, 130.54,
130.67, 141.86, 154.73. IR (KBr) cm−1: 1520 (C=N), 1233,
1081 (C–O–C), 1184 (C–N). ESI-HRMS calcd. for
C16H14FN4O+ ([M + H]+): 297.1146; found: 297.1142.
3-Phenyl-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo
[e][1,3]oxazine (2g) M.p. 164–165 °C, yield: 25 %. 1H-
NMR (CDCl3, 300 MHz) δ: 4.70 (s, 2H, –N–CH2–Ar), 5.43
(s, 2H, –O–CH2–N–), 6.90–7.22 (m, 6H, Ar–H), 7.29 (t,
2H, J = 7.5 Hz, Ar–H), 8.36 (s, 2H, Triazole-H). 13C-NMR
(CDCl3, 75 MHz) δ: 50.48, 79.89, 118.43, 118.52, 121.21,
122.08, 122.36, 122.41, 126.69, 129.41, 141.77, 147.85,
154.82. IR (KBr) cm−1:1521 (C = N), 1232, 1078 (C–O–C),
1120 (C–N). ESI-HRMS calcd. for C16H15N4O+ ([M +
H]+): 279.1240; found: 279.1242.
3-(4-Fluorophenyl)-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-
2H-benzo[e][1,3]oxazine (2l) M.p. 118–120 °C, yield:
22 %. 1H-NMR (CDCl3, 300 MHz) δ: 4.66 (s, 2H,
–N–CH2–Ar), 5.38 (s, 2H, –O–CH2–N–), 6.95–7.17 (m,
7H, Ar–H), 8.38 (s, 2H, Triazole-H). 13C-NMR (CDCl3, 75
MHz) δ: 51.26, 80.59, 115.83, 116.13, 118.58, 120.71,
120.82, 121.23, 122.16, 122.64, 126.79, 141.79, 144.33,
154.81. IR (KBr) cm−1: 1519 (C=N), 1234, 1078 (C–O–C),
1185 (C–N). ESI-HRMS calcd. for C16H14FN4O+ ([M +
H]+): 297.1146; found: 297.1148.
3-p-Tolyl-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo[e]
[1,3]oxazine (2h) M.p. 168–170 °C, yield: 27 %. 1H-NMR
(CDCl3, 300 MHz) δ: 2.29 (s, 3H, –CH3), 4.67 (s, 2H,
–N–CH2–Ar), 5.41 (s, 2H, –O–CH2–N–), 6.94(d, 1H, J =
9.0 Hz, Ar–H), 7.02–7.14 (m, 6H, Ar–H), 8.37 (s, 2H,
Triazole-H). 13C-NMR (CDCl3, 75 MHz) δ: 20.56, 50.84,
80.39, 118.47, 118.90, 121.26, 122.48, 126.63, 129.94,
131.88, 141.81, 145.53, 154.93. IR (KBr) cm−1: 1517
(C=N), 1220, 1099 (C–O–C), 1100 (C–N). ESI-HRMS
calcd. for C17H17N4O+ ([M + H]+): 293.1397; found:
293.1393.
3-(3-Chlorophenyl)-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-
2H-benzo[e][1,3]oxazine (2m) M.p. 154–156 °C, yield:
20 %. 1H-NMR (CDCl3, 300 MHz) δ: 4.70 (s, 2H,
–N–CH2–Ar), 5.41 (s, 2H, –O–CH2–N–), 6.94–7.25 (m,
7H, Ar–H), 8.39 (s, 2H, Triazole-H). 13C-NMR (CDCl3, 75
MHz) δ: 50.53, 79.28, 116.43, 118.46, 118.71, 121.24,
122.01, 122.12, 122.65, 126.89, 130.43, 135.08, 141.79,
149.04, 154.70. IR (KBr) cm−1: 1518 (C=N), 1229, 1079
(C–O–C), 1182 (C–N). ESI-HRMS calcd. for
C16H14ClN4O+ ([M + H]+): 313.0851; found: 313.0849.
3-(4-Methoxyphenyl)-6-(4H-1,2,4-triazol-4-yl)-3,4-dihy-
dro-2H-benzo[e][1,3]oxazine (2i) M.p. 133–135 °C, yield:
25 %. 1H-NMR (CDCl3, 300 MHz) δ: 3.77 (s, 3H, –OCH3),
4.63 (s, 2H, –N–CH2–Ar), 5.37 (s, 2H, –O–CH2–N–), 6.85
(d, 2H, J = 8.9 Hz, Ar-H), 6.95 (d, 1H, J = 8.7 Hz, Ar–H),
7.03 (s, 1H, Ar–H), 7.12 (t, 3H, J = 8.9 Hz, Ar–H), 8.38 (s,
2H, Triazole-H). 13C-NMR (CDCl3, 75 MHz) δ: 51.32,
3-(4-Bromophenyl)-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-
2H-benzo[e][1,3]oxazine (2n) M.p. 164–166 °C, yield:
20 %. 1H-NMR (CDCl3, 300 MHz) δ: 4.68 (s, 2H,
–N–CH2–Ar), 5.40 (s, 2H, –O–CH2–N–), 6.96 (d, 1H, J =
8.7 Hz, Ar–H), 7.00–7.05 (m, 3H, Ar–H), 7.15 (dd, 1H, J1
= 3.0 Hz, J2 = 9.0 Hz, Ar-H), 7.37–7.43 (m, 2H, Ar–H),

Med Chem Res
8.37 (s, 2H, Triazole-H). 13C-NMR (CDCl3, 75 MHz) δ:
49.34, 54.88, 82.46, 118.00, 121.38, 121.40, 121.90,
122.23, 126.61, 130.42, 131.58, 136.54, 141.66, 154.58. IR
(KBr) cm−1: 1510 (C=N), 1232, 1083 (C–O–C), 1188
(C–N). ESI-HRMS calcd. for C16H14BrN4O+ ([M + H]+):
357.0346; found: 357.0353.
(C=N), 1237, 1081 (C–O–C), 1125 (C–N). ESI-HRMS
calcd for C17H16FN4O+ ([M + H]+): 311.1303; found:
311.1305.
3-(4-Fluorobenzyl)-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-
2H-benzo[e][1,3]oxazine (2s) M.p. 153–154 °C, yield:
19 %. 1H-NMR (CDCl3, 300 MHz) δ: 3.91 (s, 2H,
–N–CH2–Ar), 4.03 (s, 2H, –N–CH2–Ar), 4.94 (s, 2H,
–O–CH2–N–), 6.96–6.99 (m, 2H, Ar–H), 7.07 (t, 2H, J =
8.6 Hz, Ar–H), 7.16 (dd, 1H, J1 = 2.5 Hz, J2 = 8.6 Hz,
Ar–H), 7.35 (dd, 2H, J1 = 6.0 Hz, J2 = 8.6 Hz, Ar–H), 8.39
(s, 2H, Triazole-H). 13C-NMR (CDCl3, 75 MHz) δ: 49.33,
54.85, 82.45, 115.32, 115.60, 118.12, 121.54, 122.01,
122.38, 126.64, 130.39, 130.50, 133.16, 133.20, 141.80,
154.77. IR (KBr) cm−1: 1510 (C=N), 1215, 1095 (C–O–C),
1122 (C–N). ESI-HRMS calcd. for C17H16FN4O+ ([M +
H]+): 311.1303; found: 311.1303.
3-Benzyl-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo[e]
[1,3]oxazine (2o) M.p. 134–136 °C, yield: 27 %. 1H-NMR
(CDCl3, 300 MHz) δ: 3.95 (s, 2H, –N–CH2–Ar), 4.04 (s,
2H, –N–CH2–Ar), 4.96 (s, 2H, –O–CH2–N–), 6.97 (d, 2H,
J = 7.9 Hz, Ar–H), 7.16 (dd, 1H, J1 = 3.0 Hz, J2 = 9.0 Hz,
Ar–H), 7.32–7.38 (m, 5H, Ar–H), 8.38 (s, 2H, Triazole-H).
13C-NMR (CDCl3, 75 MHz) δ: 49.33, 55.59, 82.66, 118.00,
121.66, 122.00, 122.24, 126.59, 127.63, 128.56, 128.86,
137.52, 141.78, 154.76. IR (KBr) cm−1: 1523 (C=N), 1219,
1067 (C–O–C), 1124 (C–N). ESI-HRMS calcd. for
C17H17N4O+ ([M + H]+): 293.1397; found: 293.1401.
3-(2,4-Difluorobenzyl)-6-(4H-1,2,4-triazol-4-yl)-3,4-dihy-
dro-2H-benzo[e][1,3]oxazine (2t) M.p. 134–136 °C, yield:
18 %. 1H-NMR (CDCl3, 300 MHz) δ: 3.94 (s, 2H,
–N–CH2–Ar), 4.05 (s, 2H, –N–CH2–Ar), 4.94 (s, 2H,
–O–CH2–N–), 6.79–7.00 (m, 4H, Ar–H), 7.17 (dd, 1H, J1
= 2.7 Hz, J2 = 8.7 Hz, Ar–H), 7.40 (dd, 1H, J1 = 8.5 Hz, J2
= 15.0 Hz, Ar–H), 8.39 (s, 2H, Triazole-H). 13C-NMR
(CDCl3, 75 MHz) δ: 48.42, 49.50, 82.48, 103.57, 103.91,
104.25, 111.24, 118.05, 121.36, 121.92, 122.33, 126.63,
131.71, 141.70, 154.58. IR (KBr) cm−1: 1518 (C=N), 1228,
1076 (C–O–C), 1131 (C–N). ESI-HRMS calcd. for
C17H15F2N4O+ ([M + H]+): 329.1208; found: 329.1213.
3-(4-Methylbenzyl)-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-
2H-benzo[e][1,3]oxazine (2p) M.p. 154–156 °C, yield:
1
29 %. H-NMR (CDCl3, 300 MHz) δ: 2.38 (s, 3H, –CH3),
3.90 (s, 2H, –N–CH2–Ar), 4.03 (s, 2H, –N–CH2–Ar), 4.95
(s, 2H, –O–CH2–N–), 6.97 (d, 2H, J = 8.5 Hz, Ar–H),
7.15–7.20 (m, 3H, Ar–H), 7.26 (d, 2H, J = 8.0 Hz, Ar–H),
8.39 (s, 2H, Triazole-H). 13C-NMR (CDCl3, 75 MHz) δ:
21.17, 49.22, 55.32, 82.65, 118.04, 121.71, 122.02, 122.30,
126.55, 128.87, 129.28, 134.38, 137.41, 141.82, 154.86. IR
(KBr) cm−1: 1520(C=N), 1220, 1000 (C–O–C), 1135
(C–N). ESI-HRMS calcd. for C18H19N4O+ ([M + H]+):
307.1553; found: 307.1550.
3-(2-Chlorobenzyl)-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-
2H-benzo[e][1,3]oxazine (2u) M.p. 150–152 °C, yield: 21
%. 1H-NMR (CDCl3, 300 MHz) δ: 4.06 (d, 4H, J = 8.1 Hz,
–N–CH2–Ar), 4.99 (s, 2H, –O–CH2–N–), 6.99 (d, 2H, J =
8.8 Hz, Ar–H), 7.18 (dd, 1H, J1 = 3.0 Hz, J2 = 6.0 Hz,
Ar–H), 7.25–7.33 (m, 2H, Ar–H), 7.41 (dd, 1H, J1 = 3.0
Hz, J2 = 6.0 Hz, Ar–H), 7.47 (dd, 1H, J1 = 3.0 Hz, J2 = 6.0
Hz, Ar–H), 8.40 (s, 2H, Triazole-H). 13C-NMR (CDCl3, 75
MHz) δ: 49.55, 52.89, 82.97, 118.06, 121.56, 121.98,
122.29, 126.56, 126.82, 128.80, 129.70, 130.44, 134.35,
135.20, 141.71, 154.67. IR (KBr) cm−1: 1524 (C=N), 1230,
1074 (C–O–C), 1130 (C–N). ESI-HRMS calcd. for
C17H16ClN4O+ ([M + H]+): 327.1007; found: 327.1012.
3-(4-Methoxybenzyl)-6-(4H-1,2,4-triazol-4-yl)-3,4-dihy-
dro-2H-benzo[e][1,3]oxazine (2q) M.p. 157–159 °C,
yield: 28 %. 1H-NMR (CDCl3, 300 MHz) δ: 3.85
(d, 5H, J = 12.7 Hz, –N–CH2–Ar, –OCH3), 4.03 (s, 2H,
–N–CH2–Ar), 4.94 (s, 2H, –O–CH2–N–), 6.89 (s, 1H,
Ar–H), 6.92 (s, 1H, Ar–H), 6.95–6.98 (m, 2H, Ar–H), 7.16
(dd, 1H, J1 = 3.0 Hz, J2 = 9.0 Hz, Ar–H), 7.28 (d, 2H, J =
6.0 Hz, Ar–H), 8.39 (s, 2H, Triazole-H). 13C-NMR (CDCl3,
75 MHz) δ: 49.14, 54.89, 55.22, 82.36, 113.86, 117.90,
121.64, 121.90, 122.14, 126.49, 129.41, 130.04, 141.70,
154.75, 159.06. IR (KBr) cm−1: 1527 (C=N), 1242, 1093
+
(C–O–C), 1128 (C–N). ESI-HRMS calcd. for C18H19N4O2
([M + H]+): 323.1503; found: 323.1498.
3-(3-Chlorobenzyl)-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-
2H-benzo[e][1,3]oxazine (2v) M.p. 163–165 °C, yield:
23 %. 1H-NMR (CDCl3, 300 MHz) δ: 3.93 (s, 2H,
–N–CH2–Ar), 4.04 (s, 2H, –N–CH2–Ar), 4.96 (s, 2H,
–O–CH2–N–), 6.98 (d, 2H, J = 3.0Hz, Ar–H), 7.18 (d, 1H,
J = 9.0Hz, Ar–H), 7.30 (s, 3H, Ar–H), 7.41 (s, 1H, Ar–H),
8.40 (s, 2H, Triazole-H). 13C-NMR (CDCl3, 75 MHz)
δ: 49.37, 55.03, 82.59, 118.02, 121.39, 121.94,
122.26,126.62, 126.78, 127.72, 128.67, 129.76, 134.40,
139.69, 141.68, 154.58. IR (KBr) cm−1: 1517 (C=N), 1228,
3-(3-Fluorobenzyl)-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-
2H-benzo[e][1,3]oxazine (2r) M.p. 138-149 °C, yield:
23 %. 1H-NMR (CDCl3, 300 MHz) δ: 4.03 (s, 4H, -N-CH2-
Ar), 4.94 (s, 2H, -O-CH2-N-), 6.98 (t, 3H, J = 10.8 Hz, Ar-
H), 7.10-7.18 (m, 3H, Ar-H), 7.31 (t, 1H, J = 7.5 Hz, Ar-H),
8.38 (s, 2H, Triazole-H). 13C-NMR (CDCl3, 75 MHz) δ:
49.37, 55.06, 82.63, 114.60, 118.02, 121.47, 121.99,
124.24, 124.25, 124.29, 126.65, 130.07, 140.28, 140.38,
141.74, 154.60, 161.36, 164.62. IR (KBr) cm−1: 1524

Med Chem Res
1079 (C–O–C), 1129 (C–N). ESI-HRMS calcd. for
Xylene-induced ear-edema model with intraperitoneally
administered compounds All test compounds and ibupro-
fen were freshly prepared (dissolved with DMSO) prior to
intraperitoneal administration at a dose of 100 mg/kg and
volume of 0.1 mL/20 g of mice weight. Control mice were
injected with vehicle (DMSO, 0.1 mL/20 g of mice weight)
only. Thirty minutes after administration, 20 μL xylene was
smeared evenly using a micropipette on the surface of the
right ear of each mouse. Thirty minutes later, a circular
tissue (7 mm diameter) was excised from both ears of
treated mice using a cylindrical borer. Mice were restrained
from struggling during the 30 min test period. The weights
of the left (untreated) and right (treated) ear sections were
recorded. Edema was quantified by analyzing the differ-
ence in weight between the left (untreated) and right (trea-
ted) ear sections. Anti-inflammatory activity was expressed
as the inhibition percentage compared to the control group.
Ibuprofen was used in parallel as a reference drug. Edema
values, expressed as mean standard deviation, were
compared statistically using one-way-ANOVA followed by
Dunnet’s post-hoc test. Differences with p values < 0.05
were considered statistically significant.
C17H16ClN4O+ ([M + H]+): 327.1007; found: 327.1003.
3-(4-Chlorobenzyl)-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-
2H-benzo[e][1,3]oxazine (2w) M.p. 164–166 °C, yield:
25 %. 1H-NMR (CDCl3, 300 MHz) δ: 3.91 (s, 2H,
–N–CH2–Ar), 4.03 (s, 2H, –N–CH2–Ar), 4.94 (s, 2H,
–O–CH2–N–), 6.98 (d, 2H, J = 6.0 Hz, Ar–H), 7.17 (dd,
1H, J1 = 3.0 Hz, J2 = 9.0 Hz, Ar–H), 7.34 (dd, 4H, J1 = 9.0
Hz, J2 = 12.0 Hz, Ar–H), 8.39 (s, 2H, Triazole-H). 13C-
NMR (CDCl3, 75 MHz) δ: 49.38, 54.91, 82.53, 118.12,
121.49, 122.00, 122.37, 126.64, 128.74, 130.15, 133.42,
136.00, 141.77, 154.73. IR (KBr) cm−1: 1519 (C=N), 1234,
1083 (C–O–C), 1134 (C–N). ESI-HRMS calcd. for
C17H16ClN4O+ ([M + H]+): 327.1007; found: 327.1013.
3-(2-Bromobenzyl)-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-
2H-benzo[e][1,3]oxazine (2x) M.p. 162–164 °C, yield:
1
24 %. H-NMR (CDCl3, 300 MHz) δ: 4.05 (d, J = 13.5 Hz,
4H, –N–CH2–Ar), 5.00 (s, 2H, –O–CH2–N–), 7.01 (s, 2H,
Ar–H), 7.20 (s, 2H, Ar–H), 7.31–7.41 (m, 1H, Ar–H), 7.48
(d, 1H, J = 3.0 Hz, Ar–H), 7.61 (d, 1H, J = 6.0 Hz, Ar–H),
8.40 (s, 2H, Triazole-H). 13C-NMR (CDCl3, 75 MHz) δ:
49.52, 55.36, 82.98, 118.09, 121.59, 122.01, 122.31,
124.65, 126.56, 127.44, 129.07, 130.56, 133.04, 136.84,
141.72, 154.70. IR (KBr) cm−1: 1525 (C=N), 1224, 1083
(C–O–C), 1138 (C–N). ESI-HRMS calcd. for
C17H16BrN4O+ ([M + H]+): 371.0502; found: 371.0502.
Xylene-induced ear-edema model with p.o. administered
compounds Two of the compounds screened by
intraperitoneal administration (compounds 2d and 2h) and
ibuprofen were homogenized in 0.5 % sodium carbox-
ymethylcellulose (CMC–Na) and administered orally at
100 mg/kg (0.4 mL/20 g body weight). Control mice
received 0.5 % CMC–Na (0.4 mL/20 g body weight) only.
To explore the peak activity of the test compounds, edema
was quantified at different time intervals after oral admin-
istration (1, 2, 3, 4, 5, and 6 h).
3-(4-Bromobenzyl)-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-
2H-benzo[e][1,3]oxazine (2y) M.p. 166–168 °C, yield:
27 %. 1H-NMR (CDCl3, 300 MHz) δ: 3.89 (s, 2H,
–N–CH2–Ar), 4.02 (s, 2H, –N–CH2–Ar), 4.93 (s, 2H,
–O–CH2–N–), 6.95–6.98 (m, 2H, Ar–H), 7.17 (dd, 1H, J1
= 3.0 Hz, J2 = 6.0 Hz, Ar–H), 7.26 (d, 2H, J = 9.0 Hz,
Ar–H), 7.49 (d, 2H, J = 8.2 Hz, Ar–H), 8.39 (s, 2H,Tria-
zole-H). 13C-NMR (CDCl3, 75 MHz) δ: 49.34, 54.88,
82.46, 118.00, 121.38, 121.40, 121.90, 122.23, 126.61,
130.42, 131.58, 136.54, 141.66, 154.58. IR (KBr) cm−1:
1523 (C=N), 1227, 1082 (C–O–C), 1135 (C–N). ESI-
HRMS calcd. for C17H16BrN4O+ ([M + H]+): 371.0502;
found: 371.0504.
Conclusion
In the present study, we described the syntheses and anti-
inflammatory activities of evaluation of novel 3-alkyl-6-
(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo[e][1,3]
oxazine derivatives (2a–2y). The results showed that
3-heptyl-6-(4H-1,2,4-triazol-4-yl)-3,4-dihydro-2H-benzo[e]
[1,3]oxazine (2d) and 3-p-tolyl-6-(4H-1,2,4-triazol-4-yl)-
3,4-dihydro-2H-benzo[e][1,3]oxazine (2h) displayed the
highest inhibition percentage, 74.04 % and 64.99 % (intra-
peritoneal administration), respectively, which were a bit
more potent than the reference drug Ibuprofen (62.65 %).
Moreover, compound 2d showed higher activity than the
reference drug at all time points by oral administration.
Pharmacology
The anti-inflammatory activity of each compound was
evaluated by examining in vivo inhibition of xylene-
induced ear edema (Pardridge, 2005) in kunming mice
(22 2 g, 8 animals per group). All of the animals were
purchased from the Laboratory of Animal Research, Yan-
bian University. Mice were acclimated to the laboratory
conditions (20–25 °C, relative humidity at 45–65 %) for
more than 1 week prior to experimentation and fed a stan-
dard pellet diet with water.
Acknowledgments This work was supported by the National Nat-
ural Science Foundation of China (No. 81360468).

Med Chem Res
Compliance with ethical standards
Kritsanida M, Mouroutsou A, Marakkos P, Pouli N,
Papakonstantinou-Garoufalias S, Pannecouque C, Witvrouw M,
DeClercq E (2002) Synthesis and antiviral activity evaluation of
some new 6-substituted 3-(1-adamantyl)-1,2,4-triazolo[3,4-b]
[1,3,4]thiadiazoles. Farmaco 57:253–257
Conflict of interest We declare that we have no conflict of interest
with respect to this study.
Kroll RA, Neuwelt EA (1998) Outwitting the blood-brain for ther-
apeutic purposes: osmotic opening and other means. Neurosugery
42:1083–1099
Kucukguzel I, Kucukguzel SG, Rollas S, Otuk-Sanis G, Ozdemir O,
Bayrak I, Altug T, Stables JP (2004) Synthesis of some
3-(arylalkylthio)-4-alkyl/aryl-5- (4-aminophenyl)-4H-1,2,4-tria-
zole derivatives and their anticonvulsant activity. Farmaco
59:893–901
Labanauskas L, Udrenaite E, Gaidelis P, Brukstus A (2004) Synthesis
of 5-(2-, 3- and 4-methoxyphenyl)-4H-1,2,4-triazole-3-thiol
derivatives exhibiting anti-inflammatory activity. Farmaco
59:255–259
References
Abdel-Aal MT, El-Sayed WA, El-Kosy SM, El-Ashry ESH (2008)
Synthesis and antiviral activity evaluation of some new 6-
substituted 3-(1-adamantyl)-1,2,4-triazolo[3,4-b][1,3,4]thiadia-
zoles. Arch Pharm 341:307–313
Adebayo D, Bjarnason I (2006) Is non-steroidal anti-inflammaory drug
(NSAID) enteropathy clinically more important than NSAID
gastropathy? Postgrad Med J 82:186–191
Lazzaroni M, Bianchi PG (2004) Gastrointestinal side-effects of tra-
ditional non-steroidal anti-inflammatory drugs and new for-
mulations. Aliment Pharm Ther 20:48–58
Li X, Yang YB, Yang Q, Sun LN, Chen WS (2009) Anti-inflammatory
and analgesic activities of Chaenomeles speciosa fractions in
laboratory animals. J Med Food 12(5):1016–1022
Liu XP, Wang Y, Lan HY, Song AH, Tsim Karl WK, Dong Tina TX,
Hu C (2010) Synthesis and anti-inflammatory activity of a novel
series of 9,10-dihydro-4H,8H-chromeno[8,7-e][1,3]oxazin-4-one
derivatives. Chem Res Chinese U 26(2):268–271
Lyman M, Lloyd DG, Ji X, Vizcaychipi MP, Ma D (2014) Neuroin-
flammation: the role and consequences. Neurosci Res 79:1–12
Momi N, Kaur S, Krishn SR, Batra SK (2012) Discovering the route
from inflammation to pancreatic cancer. Minerva Gastroenterol
Dietol 58:283–297
Mounier G, Guy C, Berthoux F, Beyens MN, Ratrema M, Ollagnier M
(2006) Severe renal adverse events with arylcarboxylic non-
steroidal anti-inflammatory drugs: results of a eight-year French
national survey. Therapie 61:255–266
Naesdal J, Brown K (2006) NSAID-associated adverse effects and
acid control aids to prevent them: a review of current treatment
options. Drug Safety 29:119–132
Pardridge WM (2005) The blood-brain barrier: bottleneck in brain
drug development. NeuroRx 2:3–14
Rabea SM, El-Koussi NA, Hassan HY, Aboul-Fadl T (2006) Synthesis
of 5-phenyl-1-(3-pyridyl)-1H-1,2,4-triazole-3-carboxylic acid
derivatives of potential anti-inflammatory activity. Arch Pharm
339:32–40
Almasirad A, Tabatabai SA, Faizi M, Kebriaeezadeh A, Mehrabi N,
Dalvandi A, Shafiee A (2004) Synthesis and anticonvulsant
activity of new 2-substituted-5-[2-(2-fluorophenoxy)phenyl]-
1,3,4-oxadiazoles and 1,2,4-triazoles. Bioorg Med Chem Lett
14:6057–6059
Botting RM (2006) Cyclooxygenase: past, present and future. J Therm
Biol 31:208–219
Cryer B (2005) NSAID-associated deaths: the rise and fall of NSAID-
associated GImortality. Am J Gastroenterol 100:1694–1695
Da Silva YK, Augusto CV, Augusto CV, de Castro Barbosa ML, de
Albuquerque Melo GM, de Queiroz AC, de Lima Matos Freire
Dias T, Júnior WB, Barreiro EJ, Lima LM, Alexandre-Moreira
MS (2010) Synthesis and pharmacological evaluation of pyrazine
N-Acylhydrazone derivatives designed as novel analgesic and
anti-inflammatory drug candidates. Bioorg Med Chem 18
(14):5007–5015
Demirbas N, Demirbas A, Alpay Karaoglu S, Celik E (2005) Synthesis
and antimicrobial activities of some new [1,2,4]triazolo[3,4-b]
[1,3,4]thiadiazoles and [1,2,4]triazolo[3,4-b] [1,3,4]thiadiazines.
Arch Org Chem i:75–91
Deng XQ, Song MX, Zheng Y, Quan ZS (2014) Design, synthesis and
evaluation of the antidepressant and anticonvulsant activities of
triazole-containing quinolinones. Eur J Med Chem 73:217–224
Duran A, Dogan HN, Rollas S (2002) Synthesis and preliminary
anticancer activity of new 1,4-dihydro-3-(3-hydroxy-2-naphthyl)-
4-substituted-5H-1,2,4-triazoline-5-thiones. Farmaco 57:559–564
Eccles R (2006) Efficacy and safety of over-the-counter analgesics in
the treatment of common cold and flu. J Clin Pharm Ther
31:309–319
EI Azab IH, Khaled KM (2015) Synthesis and reactivity of enaminone
of naphtho[b]1,4-oxazine: One pot synthesis of novel isolated and
heterocycle-fused derivatives with antimicrobial and antifungal
activities. Russ J Bioorg Chem 41(4):421–436
Schneider V, Levesque LE, Zhang B, Hutchinson T, Brophy JM
(2006) Association of selective and conventional non-steroidal
anti-inflammatory drugs with acute renal failure: a population-
based, nested case-control analysis. Am
J
Epidemiol
164:881–889
Sharma S, Gangal S, Rauf A, Zahin M (2008) Synthesis, antibacterial
and antifungal activity of some novel 3,5-disubstituted-1H-1,2,4-
triazoles. Arch Pharm 341:714–720
Sindhu TJ, Paul David, Chandran Meena, Bhat AR, Krishnakumar K
(2014) Antimycobacterial activity of 1, 4-oxazines and 1, 4-
thiazines. World J Pharm Pharm Sci 3(2):1655–1662
Ferrero-Miliani L, Nielsen OH, Andersen PS, Girardin SE (2007)
Chronic inflammation: importance of NOD2 and NALP3 in
interleukin-1β generation. Clin Exp Immunol 147:227–235
Holla BS, Veerendra B, Shivananda MK, Poojary B (2003) Synthesis
characterization and anticancer activity studies on some Mannich
bases derived from 1,2,4-triazoles. Eur J Med Chem 38:759–767
James MW, Hawkey CJ (2003) Assessment of non-steroidal anti-
inflammatory drug(NSAID) damage in the human gastrointestinal
tract. Br J Clin Pharmacol 56:146–155
Kalirajan R, Kulshrestha Vivek, Sankar S, Jubie S (2012) Docking
studies, synthesis, characterization of some novel oxazine sub-
stituted 9-anilinoacridine derivatives and evaluation for their
antioxidant and anticancer activities as topoisomerase II inhibi-
tors. Eur J Med Chem 56:217–224
Sng BL, Schug SA (2009) The role of opioids in managing chronic
non-cancer pain. Ann Acad Med Singap 38:960–966
Sowemimo A, Samuel F, Fageyinbo MS (2013) Anti-inflammatory
activity of Markhamia tomentosa (Benth.) K. Schum. Ex Engl.
ethanolic leaf extract. J Ethnopharmacol 149:191–194
Stocks MJ, Cheshire DR, Reynolds R (2004) Efficient and regiospe-
cific one-pot synthesis of substituted 1,2,4-triazoles. Org Lett
6:2969–2971
Tozkoparan B, Kupeli E, Yesilada E, Ertan M (2007) Preparation of 5-
aryl-3-alkylthio-l,2,4-triazoles and corresponding sulfones with
Kraemer FW, Rose JB (2009) Pharmacologic manageent of acute
pediatric pain. Anesthesiol Clin 2:241–268

Med Chem Res
anti-inflammatory-analgesic activity. Bioorg Med Chem
Varvaresou A, Siatra-Papastaikoudi T, Tsotinis A, Tsantili-
Kakoulidou A, Vamvakides A (1998) Synthesis, lipophilicity
and biological evaluation of indole containing derivatives of
1,3,4-thiadiazole and 1,2,4-triazole. Farmaco 53:320–326
Wen X, Wang SB, Liu DC, Gong GH, Quan ZS (2015) Synthesis and
evaluation of the anti-inflammatory activity of quinoline deriva-
tives. Med Chem Res 6(24):2591–2603
15:1808–1814
Turan-Zitouni G, Kaplancikli ZA, Yildiz MT, Chevallet P, Kaya D
(2005) Synthesis and antimicrobial activity of 4-phenyl/
cyclohexyl-5-(1-phenoxyethyl)-3- [N-(2-thiazolyl)acetamido]
thio-4H-1,2,4-triazole derivatives. Eur
607–613
J Med Chem 40:
Turan-Zitouni G, Sivaci M, Kilic FS, Erol K (2001) Synthesis of some
triazolylantipyrine derivatives and investigation of analgesic
activity. Eur J Med Chem 36:685–689
Zahradnik HP, Hanjalic-Beck A, Groth K (2010) Nonsteroidal anti-
inflammatory drugs and hormonal contraceptives for pain relief
from dysmenorrhea: a review. Contraception 81:185–196