Design and synthesis of 10-alkoxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4] oxazepine derivatives with anticonvulsant activity

Article abstract of DOI:10.1016/j.ejmech.2010.03.041

A series of novel 10-alkoxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4] oxazepine derivatives were synthesized and screened for their anticonvulsant activities by the maximal electroshock (MES) test and their neurotoxicity was evaluated by the rotarod neurotoxicity test (Tox). In the MES test, compound 10-Heptyloxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4]oxazepine (8f) was found to possess better anticonvulsant activity and higher safety than marketed drugs carbamazepine and phenytoin with an ED50 value of 6.9 mg/kg a PI value of 9.5. To explain the possible mechanism of anticonvulsant activity, compound 8f was tested in pentylenetetrazole, isoniazid, thiosemicarbazide, 3-mercaptopropionic acid and Bicuculline induced seizures tests. The results suggest that compound 8f exerts anticonvulsant activity through GABA-mediated mechanism.

Full text of DOI:10.1016/j.ejmech.2010.03.041

European Journal of Medicinal Chemistry 45 (2010) 3080e3086
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Design and synthesis of 10-alkoxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4]
oxazepine derivatives with anticonvulsant activity
,
,
b,
Xian-Qing Deng b, Cheng-Xi Wei a b, Fu-Nan Li b, Zhi-Gang Sun a , Zhe-Shan Quan
**
*
a Institute of Neurosurgery, Inner Mongolia University for Nationalities, No. 1742, Holin River Street, Tongliao, Inner Mongolia Autonomous Region 028007, China
b College of Pharmacy, Yanbian University, No. 1829, JuZi Street, Yanji, Jilin 133000, China
a r t i c l e i n f o
a b s t r a c t
Article history:
A
series of novel 10-alkoxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4]oxazepine derivatives were
Received 18 February 2010
Received in revised form
24 March 2010
Accepted 29 March 2010
Available online 3 April 2010
synthesized and screened for their anticonvulsant activities by the maximal electroshock (MES) test and
their neurotoxicity was evaluated by the rotarod neurotoxicity test (Tox). In the MES test, compound
10-Heptyloxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4]oxazepine (8f) was found to possess better
anticonvulsant activity and higher safety than marketed drugs carbamazepine and phenytoin with an
ED50 value of 6.9 mg/kg a PI value of 9.5. To explain the possible mechanism of anticonvulsant activity,
compound 8f was tested in pentylenetetrazole, isoniazid, thiosemicarbazide, 3-mercaptopropionic acid
and Bicuculline induced seizures tests. The results suggest that compound 8f exerts anticonvulsant
activity through GABA-mediated mechanism.
Keywords:
Synthesis
Triazole
Benzo[f][1,4]oxazepine
Anticonvulsant
Maximal electroshock
Ó 2010 Elsevier Masson SAS. All rights reserved.
1. Introduction
Intent on exploring effective compounds with lower neurotox-
icity, a series of 10-alkoxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4]
Epilepsy, one of the most frequent neurological afflictions in
man characterized by excessive temporary neuronal discharges
resulting in uncontrolled convulsion, inflicts more than 2 million
Americans and 60 million people worldwide [1,2]. Although the
current drugs provide adequate seizure control in many patients, it
is roughly estimated that up to 28e30% of patients are poorly
treated with the available antiepileptic drugs (AEDs) [3,4]. More-
over, many AEDs have serious side effects [5e10], and lifelong
medication may be required. Toxicity, intolerance, and lack of
efficacy are the limitations of the current AEDs. Therefore, the
continued search for safer and more effective new AEDs is
necessary.
oxazepines (Fig. 1, II) were designed and synthesized in this study.
Compounds II, the ring enlargement analogues of compounds I
through inserting an oxygen atom, were anticipated to possess
a better anticonvulsant activity. Their structures were characterized
using IR, 1H NMR, MS and elemental analysis techniques. Their
anticonvulsant activity was evaluated using MES test in mice and
their neurotoxicity was evaluated with the rotarod test. For
explaining the possible mechanism of action, the most active
compound (8k) was tested in Pentylenetetrazole (PTZ), Isoniazid
(ISO), thiosemicarbazide (TSC), 3-Mercaptopropionic acid (3-MP),
and Bicuculline (BIC) induced seizure tests.
In our previous studies [11,12], series of 6-alkyloxyl-3,4-dihydro-
2(1H)-quinolines and 7-alkoxy-4,5-dihydro-[1,2,4]triazole[4,3-a]
quinolines (Fig. 1, I) were synthesized and tested for anticonvulsant
activity. In these synthesized derivatives, 7-(4-fluorobenzyloxy)-
4,5-di-hydro-[1,2,4]triazole[4,3-a]quinoline displayed the best
activity, having ED50 values of 11.8 mg/kg in the maximal electro-
shock test (MES).
2. Chemistry
Compounds were prepared as outlined in Scheme 1. The starting
material 6-methoxy-2,3-dihydrochromen-4-one (1) was prepared
by the method reported by Cai [13]. The Beckmann rearrangement
reaction is a good method to obtain seven-membered heterocyclic
amides, especially the 1, 4-benzoxazepin-5(2H)-ones [14,15], This
method was used in the next step. Compound (1) reacted with
hydroxylamine chloride to form 6-methoxy-2,3- dihydrochromen-
4-one oxime (2) with a high yield, which then, under the Lewis acid
condition, using polyphosphoric acid (PPA) in this case, became
compound 3. In this step, the product in the Beckmann
* Corresponding author. Tel./fax: þ86 433 2660606.
** Corresponding author. Tel.: þ86 475 8267818; fax: þ86 475 8267813.
E-mail addresses: sunzhigang101@yahoo.cn (Z.-G. Sun), zsquan@ybu.edu.cn
(Z.-S. Quan).
0223-5234/$ e see front matter Ó 2010 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2010.03.041

X.-Q. Deng et al. / European Journal of Medicinal Chemistry 45 (2010) 3080e3086
3081
from the Laboratory of Animal Research, College of Pharmacy,
Yanbian University.
Most of the titled compounds possessed better activity were
quantified their anticonvulsant activity, and the compound 8f was
tested in sc-PTZ, isoniazid, 3-MP, thiosemicarbazide, and Bicucul-
line induced seizures tests.
O
R
R
N
N
N
N
N
N
Fig. 1. Structure of compounds I and II.
4. Results and discussion
rearrangement reaction was mostly the expected product, 7-
methoxy-3,4-dihydrobenzo[f][1,4]oxazepin-5(2H)-one (3), rather
than the regioisomer. This might be ascribed to the greater diffi-
culty for the aryl group to migrate.
As with any other class of drugs, the preclinical discovery and
development of a new chemical entity for the treatment of epilepsy
rely heavily on the use of predictable animal models. At the present
time, there are three in vivo models that are routinely used by most
AED discovery programs. They include the maximal electroshock
(MES), the subcutaneous pentylenetetrazol (sc-PTZ), and the
kindling model. Of these, the MES and sc-PTZ seizure models
represent the two animal seizure models most widely used in the
search for new AEDs [18,19]. In this study, the MES seizure model
was used for preliminary (phase-I) screening of compounds 6, 8aes
and the results were presented in Table 1. As shown in Table 1, all of
the compounds were active in the MES test, indicative of their
ability to prevent seizure spread, among which five compounds
8ceg showed protection against MES-induced seizure at the dose
of 10 mg/kg. At a dose of 30 mg/kg, most compounds showed
protection except 6, 8a, 8m, 8n, and 8qes. At a dose of 100 mg/kg
all compounds showed protection except 6. None of the
compounds showed protection in the 4 h period.
7-Methoxy-3,4-dihydrobenzo[f][1,4]oxazepine-5(2H)-thione (4)
was prepared by the reaction of compound 3 with phosphorous
pentasulfide in acetonitrile in the presence of triethylamine.
Compounds 4 reacted further with hydrazine hydrate in THF to
afford 1-(7-methoxy-3,4-dihydrobenzo[f][1,4]oxazepin-5(2H)-yl-
idene)hydrazine (5), which reacted with formic acid to give 10-
methoxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4]oxazepine (6).
Demethylation of compound 6 by treatment with dichloromethane
and boron tribromide produced 5, 6-dihydro-triazolo[4,3-d]benzo
[f][1,4]oxazepin-10-ol (7). Finally, compounds 8aes were achieved
by reacting compound 7 with halogenated hydrocarbon in aceto-
nitrile in the presence of K2CO3 (Scheme 1).
3. Pharmacology
As a result of preliminary screening, compounds 8bep were
subjected to phase-II trials for quantification of their anticonvulsant
activity (indicated by ED50) and neurotoxicity (indicated by TD50) in
mice. Results of the quantitative test for selected compounds, along
with the data on the standard drug carbamazepine and phenytoin,
are reported in Table 2. Among the tested compounds, 10-Hepty-
All the titled compounds (8aes) were screened for their anti-
convulsant activity by using the most adopted seizure models e the
Maximal electroshock (MES) test. Neurotoxicity was assessed by
rotarod test. The MES test and rotarod test were carried out by the
methods described in the Antiepileptic Drug Development Program
(ADD) of the National Institutes of Health following previously
described testing procedures (USA) [16,17]. All compounds, which
were dissolved in DMSO, were evaluated for anticonvulsant activ-
ities with KunMing mice in the 18e22 g weight range purchased
loxy-5,
which gave an ED50 value of 6.9 mg/kg and a TD50 value of 65.7 mg/
kg resulting in a higher protective index (PI) value e that is, TD50
6-dihydro-triazolo[4,3-d]benzo[f][1,4]oxazepine
(8f),
/
ED50 ¼ 9.5 when compared to carbamazepine and phenytoin.
O
O
O
.
H2NOH HCl
PPA
NH
H3CO
H3CO
H3CO
NOH
O
O
3
2
1
O
O
N
P2S5
CH3CN/TEA
HCOOH
NH2NH2H2O
THF
NH
NH
H3CO
H3CO
S
NH2
5
4
O
O
O
N
RX
K2CO3
BBr3
CH2Cl2
N
HO
N
N
H3CO
N
N
RO
N
N
N
8a-8s
7
6
Scheme 1. Synthetic route of target compounds (8aes).

3082
X.-Q. Deng et al. / European Journal of Medicinal Chemistry 45 (2010) 3080e3086
Table 1
Comparing the derivatives with different F-substitutionpositions on
the benzyl ring, their activity order was o-F > m-F > p-F. Activity
order of the Cl and Br substituted derivatives was o-Cl > p-Cl > m-Cl
and m-Br > o-Br > p-Br.
Phase-I evaluation of anticonvulsant activity in mice (i.p.).
Compds.
R
Dosage (mg/kg)
MESa
0.5 h
4 h
Two electron-donor derivatives were also designed and
prepared, containing p-CH3 and p-OCH3. The pharmacology test
revealed that their activities were obviously lower than the halogen
substituted derivatives with an ED50 > 100 mg/kg.
6
eCH3
eC2H5
n-C3H7
n-C4H9
n-C5H11
n-C6H13
n-C7H15
n-C8H17
300
100
30
10
10
10
10
10
30
30
30
30
30
100
100
30
2/6
2/6
4/6
3/6
1/6
4/6
6/6
2/6
6/6
6/6
5/6
4/6
3/6
4/6
5/6
2/6
4/6
2/6
2/6
1/6
0/6
0/6
0/6
0/6
0/6
0/6
0/6
0/6
0/6
0/6
0/6
0/6
0/6
0/6
0/6
0/6
0/6
0/6
0/6
0/6
8a
8b
8c
8d
8e
8f
8g
8h
8i
8j
8k
8l
8m
8n
8o
8p
8q
8r
8s
The length of the alkyl chain appeared to have a direct impact on
anticonvulsant activity of the 10-alkoxy-5, 6-dihydro-triazolo[4,3-
d]benzo[f][1,4]oxazepine derivatives. From compounds 6, 8a to 8f,
as alkyl chain length increased, ED50 gradually increased with the
compound 8f (with the n-heptyl substituted group) being the most
active. The trend reversed, however, when the alkyl chain had more
than seven carbon atoms. Obviously, the activity curve of the alkyl
chain substituted derivatives is bell-shaped with a maximum
activity peak. Compound 8f, with the maximum activity peak,
reflected the optimal partition coefficient associated with the
easiest crossing of the biological membranes. Compound 8f, with
ED50 value of 6.9 mg/kg and PI value of 9.5, was the most potent of
all the tested and superior to the carbamazepine and phenytoin.
To further investigate the effects of the anticonvulsant activity in
several different models and speculate about the possible mecha-
nism of anticonvulsant action, compounds 8f was tested against
convulsions induced by chemical substances, including PTZ, ISO, 3-
MP, TSC, and BIC. Compounds 8f was administered into mice i.p. at
a dose of 30 mg/kg, which was higher than four times its ED50
value and far below its TD50 value. The reference drug carbama-
zepine was also administered i.p. at a dose of 30 mg/kg.
In the sc-PTZ model, compounds 8f partially inhibited the clonic
seizures induced by sc-PTZ, while the reference drug carbamaze-
pine did not inhibit the clonic seizures induced by sc-PTZ. Both of
them inhibited the tonic seizures and reduced lethality compared
with the control group (Table 3). In the isoniazid model, carba-
mazepine inhibited the clonic seizures, tonic seizures and death
induced by isoniazid at the rates of 40%, 100% and 100%, respec-
tively; and compound 8f showed complete inhibition of the clonic
seizures, tonic seizures and death induced by isoniazid (Table 3).
eCH2C6H5
eCH2C6H4 (o-F)
eCH2C6H4 (m-F)
eCH2C6H4 (p-F)
eCH2C6H4 (o-Cl)
eCH2C6H4 (m-Cl)
eCH2C6H4 (p-Cl)
eCH2C6H4(o-Br)
eCH2C6H4(m-Br)
eCH2C6H4(p-Br)
eCH2C6H4(p-CH3)
eCH2C6H4(p-OCH3)
30
100
100
100
a
Maximal electroshock test (number of animals protected/number of animals
tested), the number of mice is six.
Therefore, compound 8f was selected to be the most active and
promising compound in this work. With an ED50 value of 11.0, 10.0
and 11.0 respectively, compounds 8c, 8e and 8g were nearly equi-
potent to carbamazepine, but were more toxic than carbamazepine.
And the remaining 11 compounds 8b, 8d, and 8hep exhibited
comparatively weaker activity than carbamazepine and phenytoin.
Analyzing the activities of the synthesized compounds the
following structureeactivity relationships (SAR) were obtained.
Besides the derivative 8h (non-substituted in the ring of benzyl
group), some halogen substituted derivatives (8ieq) were designed
and synthesized in this paper. Introduction of halogen on the benzyl
ring decreased the anticonvulsant activity (compared with 8h),
although theo-F derivative8i exhibitedhigher safety with PIvalue of
5.1 compared with 8h (PI ¼ 4.6). Comparison of the halogen
substituted derivatives indicated that different halogen atoms
contributed to the anticonvulsant activity in the order of F > Cl, Br.
PTZ and ISO have been reported to produce seizures by inhibiting
g-
aminobutyric acid (GABA) neurotransmission [20,21]. GABA is the
Table 2
Quantitative anticonvulsant data in mice (i.p.).
Compds.
R
ED50 (mg/kg) (MES)
TD50 (mg/kg) (Rotarod)
PIa
6
eCH3
>100
eb
e
8a
8b
8c
8d
8e
8f
8g
8h
8i
8j
8k
8l
8m
8n
8o
8p
eC2H5
n-C3H7
n-C4H9
n-C5H11
n-C6H13
n-C7H15
n-C8H17
eCH2C6H5
eCH2C6H4 (o-F)
eCH2C6H4 (m-F)
eCH2C6H4 (p-F)
eCH2C6H4 (o-Cl)
eCH2C6H4 (m-Cl)
eCH2C6H4 (p-Cl)
eCH2C6H4(o-Br)
eCH2C6H4(m-Br)
eCH2C6H4(p-Br)
eCH2C6H4(p-CH3)
eCH2C6H4(p-OCH3)
e
>100
e
e
19.0 (17.1e21.2)c
11.0 (9.8e12.2)
15.8 (14.2e17.6)
10.0 (8.1e12.4)
6.9 (5.6e8.5)
11.0 (9.9e12.2)
16.4 (14.7e18.2)
18.0 (16.2e20.0)
23.7 (21.3e26.4)
27.4 (24.6e30.5)
38.3 (34.4e42.6)
82.2 (73.9e91.4)
60.0 (53.8e66.9)
41.7 (33.7e51.6)
25.0 (20.2e30.9)
>100
54.8 (49.3e61.0)
45.6 (41.0e50.7)
60.0 (48.5e74.2)
60.0 (48.5e74.2)
65.7 (59.1e73.1)
63.4 (57.6e69.7)
76.0 (69.1e83.6)
91.3 (83.0e100.4)
76.0 (69.1e83.6)
63.4 (57.6e69.7)
91.3 (82.1e101.6)
126.8 (114.0e141.1)
109.6 (98.5e121.9)
109.6 (98.5e121.9)
91.3 (83.0e100.4)
e
2.9
4.2
3.8
6.0
9.5
5.8
4.6
5.1
3.2
2.3
2.4
1.5
1.8
2.6
3.6
e
8q
8r
8s
>100
>100
11.8 (9.7e14.1)
9.5 (8.1e10.4)
e
e
e
e
Carbamazepine
Phenytoin
76.1(69.1e83.7)
65.5 (52.5e72.9)
6.4
6.9
e
a
PI ¼ Protective (TD50/ED50).
b
Not test.
c
The 95% confidence limits.

X.-Q. Deng et al. / European Journal of Medicinal Chemistry 45 (2010) 3080e3086
3083
Table 3
Effects of compound 8f on chemically-induced seizures in mice.
Chemical substances
Pentylenetetrazol
Compound
Doses (mg/kg)
Test time (h)
Clonic seizures (%)
Tonic seizures (%)
Lethality (%)
DMSO
Carbamazepine
8f
e
0.5
0.5
0.5
100
100
80
40
0
0
40
0
0
30
30
Isoniazid
DMSO
Carbamazepine
8f
e
1
1
1
100
60
0
100
0
0
60
0
0
30
30
3-Mercaptopropionic acid
Thiosemicarbazide
Bicuculline
DMSO
Carbamazepine
8f
e
0.5
0.5
0.5
100
100
100
100
0
0
100
0
20
30
30
DMSO
Carbamazepine
8f
e
2.5
2.5
2.5
100
100
100
100
0
30
80
0
30
30
30
DMSO
Carbamazepine
8f
e
0.5
0.5
0.5
100
100
100
100
0
0
100
20
0
30
30
main inhibitory neurotransmitter in the brain, and is widely
implicated in epilepsy. Inhibition of GABAergic neurotransmission
or activity has been shown to promote and facilitate seizures [22],
while enhancement of GABAergic neurotransmission is known to
inhibit or attenuate seizures. The findings of the present study
suggest that the newly synthesized compound 8f might have
inhibited or attenuated pentylenetetrazole-induced seizures and
isoniazid-induced seizures in mice by enhancing GABAergic
neurotransmission.
isoniazid, 3-MP, thiosemicarbazide, and Bicuculline. These experi-
ments suggested that compound 8f exert anticonvulsant activity
through GABA-mediated mechanisms, such as effecting GABAergic
neurotransmission, activating GAD, inhibiting GABA-T or agonizing
GABAA receptor in the brain.
6. Experimental protocols
6.1. Chemistry
In the 3-MP induced seizure model, carbamazepine inhibited the
clonic seizures, tonic seizures and death at the rates of 0%,100%, and
100%, respectively. In comparison, compounds 8f showed the anti-
convulsant effect similar to that of carbamazepine in inhibiting the
clonic and tonic seizures, and showed partial inhibition of the death
induced by 3-MP with the inhibition rates of 0%, 100% and 80%,
respectively (Table 3). In the TSC-induced seizure model, the anti-
convulsant effect is similar to that of the 3-MP induced seizure
model. Compared with the control group, carbamazepine showed
inhibition at the rates of 0%,100% and 100%, respectivelyof the clonic
seizures, tonic seizures and death. Compound 8f showed inhibition
at the rates of 0%, 70% and 70%, respectively (Table 3). 3-MP and TSC
were competitive inhibitors of GABA synthesis enzyme glutamate
decarboxylase (GAD), and they inhibit the synthesis of GABA
resulting in decrease of GABA level in the brain [23]. Compound 8f
showed moderate antagonism to 3-MP induced seizures and thio-
semicarbazide-induced seizures, suggesting that it might activate
GAD or inhibit aminotransferase (GABA-T) in the brain.
In the BIC induced seizure model, both carbamazepine and 8f
inhibited the tonic seizures and death, and did not inhibit clonic
seizures. Carbamazepine showed inhibition at the rate of 0%, 100%
and 80% of the clonic seizures, tonic seizures and death, respec-
tively. And 8f showed inhibition at the rates of 0%, 100% and 80%,
respectively (Table 3). BIC is a competitive antagonist of GABAA
receptor. BIC produces convulsions through its antagonism of
GABAA receptor [24]. Compound 8f can inhibit the seizures induced
by BIC, which suggested that it exerts anticonvulsant activity at
least partially through GABAA-mediated mechanisms.
Melting points were determined in open capillary tubes and
were uncorrected. IR spectra were recorded (in KBr) on IRPrestige-
21. 1H NMR spectra were measured on an AV-300(Bruker,
Switzerland), and all chemical shifts were given in ppm relative to
tetramethysilane. Mass spectra were measured on an HP1100LC
(Agilent Technologies, USA). Elemental analyses were performed
on a 204Q CHN (Perkin Elmer, USA). The major chemicals were
purchased from Aldrich Chemical Corporation.
6.1.1. Synthesis of 6-methoxy-2,3-dihydrochromen-4-one oxime (2)
6-Methoxy-2,3-dihydrochromen-4-one (7.8 g, 44 mmol), pyri-
dine (8 mL) and hydroxylamine chloride (9.17 g, 132 mmol) were
placed into a round-bottomed flask containing 150 mL of methanol.
The reaction mixture was stirred for 4 h at 70 ꢀC. After removing
most of the solvent, the mixture was added to 100 ml of ice-water
and filtered to a white solid.
M.p. 119e121 ꢀC, yield ¼ 91.5%. 1H NMR (DMSO-d6, 300 MHz),
d
2.79 (t, 2H, J ¼ 6.1 Hz, NeCH2), 3.73 (s, 3H, OeCH3), 4.11 (t, 2H,
J ¼ 6.1 HZ, OeCH2), 6.82e7.26 (m, 3H, Ar-H), 11.26 (s, 1H, NeOH). IR
(KBr) cmꢁ1: 3345 (OeH), 1616 (C]N). MS m/z 194 (M þ 1).
6.1.2. Synthesis of 7-methoxy-3,4-dihydrobenzo[f][1,4]oxazepin-5
(2H)-one (3)
Compound 2 (2.6 g, 13 mmol) and polyphosphoric acid (45 g)
were placed into a three-necked round-bottomed flask. The
mixture was heated and stirred with a blade stirrer at 90 ꢀC for
4 h. A mass of water was added to the mixture after the
temperature of the mixture was equal to room temperature, and
then the aqueous layer was extracted by CH2Cl2 3 times. The
combined organic layer was dried overnight with anhydrous
magnesium sulfate and evaporated under reduced pressure to get
a light yellow solid.
5. Conclusion
In conclusion, the results of this study demonstrated that
10-alkoxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4]oxazepine deriv-
atives have potent anticonvulsant activity. Especially, compound 8f
showed better anticonvulsant activity and higher safety than mar-
keted drugs carbamazepine and phenytoin. In addition, compound 8f
demonstrated antagonistic activity against seizures induced by PTZ,
M.p. 90e92 ꢀC, yield ¼ 61.5%. 1H NMR (CDCl3, 300 MHz),
d3.24
(q, 2H, J ¼ 5.2 Hz, NeCH2), 3.73 (s, 3H, OeCH3), 4.17 (t, 2H,
J ¼ 5.0 Hz, OeCH2), 6.96 (d, 1H, J ¼ 8.8 Hz, Ar-H), 7.03 (dd, 1H,
J1 ¼ 2.9 Hz, J2 ¼ 8.8 Hz, Ar-H), 7.16 (d, 1H, J1 ¼ 2.9 Hz, Ar-H). 8.34

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X.-Q. Deng et al. / European Journal of Medicinal Chemistry 45 (2010) 3080e3086
(s, 1H, eNHe). IR (KBr) cmꢁ1: 3204 (NH), 1674 (C]O). MS (m/z):
194 (M þ 1).
(m, 2H, Ar-H), 7.63 (s, 1H, Ar-H), 8.04 (s, 1H, OeH), 9.76 (s, 1H, N]
CH). IR (KBr) cmꢁ1: 3340 (OeH), 1628 (C]N), 1348 (CeN), 1121
(NeN). MS m/z 204 (M þ 1). Anal. Calcd. for C10H9N3O2: C, 59.11; H,
4.46; N, 20.68. Found: C, 59.18; H, 4.54; N, 20.69.
6.1.3. Synthesis of 7-methoxy-3,4-dihydrobenzo[f][1,4]oxazepine-5
(2H)-thione (4)
To a stirring mixture of acetonitrile and triethylamine in a three-
necked round-bottomed flask in an ice bath, P2S5 (1.2 eq), divided
into multiple portions, was added one portion at a time after the
previous portion had completely dissolved. Then, 7-methoxy-3,4-
dihydrobenzo[f][1,4]oxazepin-5(2H)-one compound 3 was added
and the solutionwas refluxed for 6 h under nitrogen. After removing
the solvent under reduced pressure, the residue was dissolved in
dichloromethane (30 mL), washed with water (3 ꢂ 30 mL) and dried
over anhydrous MgSO4. Evaporation of the solvents gave a crude
product, which was purified by silica gel column chromatography
with dichloromethane to give a light yellow solid (4).
6.1.7. General procedure for the synthesis of 10-alkoxy-5, 6-dihydro-tri
azolo[4,3-d]benzo[f] [1,4]oxazepine derivatives (8aes)
K2CO3 (1.24 g, 9 mmol) and 5, 6-dihydro-triazolo[4,3-d]benzo[f]
[1,4]oxazepin-10-ol (7) (3 mmol) were dissolved in acetonitrile
(50 ml) and refluxed for 30 min, then alkyl bromide or benzyl
chloride derivatives (3.3 mmol) were added into the mixture
accompanied with some of benzyltriethylamine chloride (TEBA).
The reaction mixture was heated at reflux temperature for 4e24 h
then poured into 100 ml of water. Aqueous layer was extracted with
dichloromethane (30 ml ꢂ 3). The combined layer of dichloro-
methane was dried by anhydrous MgSO4. The evaporation of the
solvent gave a crude product, which was purified by silica gel
column chromatography with CH2Cl2eCH3OH (40:1) to a white
solid. The yield, melting point and spectral data of each compound
were given below.
M.p. 114e116 ꢀC, yield ¼ 62.5%. 1H NMR (CDCl3, 300 MHz),
d3.51
(d, 2H, J ¼ 5.8 Hz, NeCH2), 3.85 (s, 3H, OeCH3), 4.39 (t, 2H, J ¼ 5.8
HZ, OeCH2), 6.98 (dd, 1H, J1 ¼ 2.9 Hz, J2 ¼ 8.9 Hz, Ar-H), 7.02 (d, 1H,
J ¼ 8.9 Hz, Ar-H), 7.51 (d, 1H, J ¼ 2.9 Hz, Ar-H), 9.53 (s, 1H, NeH). IR
(KBr) cmꢁ1: 3145 (NeH), 1256 (CeN). MS m/z 210 (M þ 1). Anal.
Calcd. for C10H11NO2S: C, 57.39; H, 5.30; N, 6.69; S, 15.32. Found:
C, 57.48; H, 5.46; N, 6.49; S, 15.19.
6.1.7.1. 10-Ethoxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4]oxazepine
(8a). M.p. 134e135 ꢀC, yield ¼ 74.5%. 1H NMR (CDCl3, 300 MHz),
d
1.42 (t, 3H, J ¼ 6.9 Hz, CH3), 4.10 (q, 2H, J ¼ 6.9 Hz, OeCH2), 4.43
6.1.4. Synthesis of 1-(7-methoxy-3,4-dihydrobenzo[f][1,4]oxazepin-5
(2H)-ylidene) hydrazine (5)
(s, 4H, NeCH2CH2eO), 6.92 (dd, 1H, J1 ¼ 8.9 Hz, J2 ¼ 2.6 Hz, Ar-H),
6.98 (d, 1H, J ¼ 8.9 Hz, Ar-H), 8.08 (d, 1H, J ¼ 2.6 Hz, Ar-H), 8.21
(s, 1H, N]CH). IR (KBr) cmꢁ1: 1619 (C]N), 1276 (CeN), 1138 (NeN).
MS m/z 232 (M þ 1). Anal. Calcd. for C12H13N3O2: C, 62.33; H, 5.67;
N, 18.17. Found: C, 62.47; H, 5.81; N, 18.01.
7-Methoxy-3,4-dihydrobenzo[f][1,4]oxazepine-5(2H)-thione (4)
(0.79 g, 3.8 mmol) was dissolved in tetrahydrofuran in a round-
bottomed flask and 0.95 g of anhydrous hydrazine (19 mmol) was
added. After the mixture was refluxed for 8 h, the solvent and excess
hydrazine were removed under reduced pressure to yield a yellow
solid, which was used in the next step without refinement.
6.1.7.2. 10-Propoxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4]oxaze-
pine (8b). M.p. 99e100 ꢀC, yield
¼
79.1%. 1H NMR (CDCl3,
M.p. 149e150 ꢀC, yield ¼ 87.6%. 1H NMR (CDCl3, 300 MHz),
d
3.31
300 MHz),
d1.04 (t, 3H, J ¼ 7.4 Hz, CH3), 1.75e1.87 (m, 2H, CH2), 3.98
(t, 2H, J ¼ 5.6 Hz, NeCH2), 3.80 (s, 3H, OeCH3), 4.14 (t, 2H, J ¼ 5.6 HZ,
OeCH2), 6.88 (dd, 1H, J1 ¼ 3.0 Hz, J2 ¼ 8.7 Hz, Ar-H), 6.95 (d, 1H,
J ¼ 8.7 Hz, Ar-H), 7.12 (d, 1H, J ¼ 3.0 Hz, Ar-H). IR (KBr) cmꢁ1: 3323
(NeH),1641 (C]N). MS m/z 208 (M þ 1). Anal. Calcd. for C10H13N3O2:
C, 57.96; H, 6.32; N, 20.28. Found: C, 58.12; H, 6.39; N, 20.09.
(t, 2H, J ¼ 6.6 Hz, OeCH2), 4.43 (s, 4H, NeCH2CH2eO), 6.92 (dd, 1H,
J1 ¼ 8.9 Hz, J2 ¼ 2.8 Hz, Ar-H), 6.97 (d, 1H, J ¼ 8.9 Hz, Ar-H), 8.07 (d,
1H, J ¼ 2.8 Hz, Ar-H), 8.19 (s, 1H, N]CH). IR (KBr) cmꢁ1: 1616
(C]N), 1271 (CeN), 1132 (NeN). MS m/z 246 (M þ 1). Anal. Calcd.
for C13H15N3O2: C, 63.66; H, 6.16; N, 17.13. Found: C, 63.82; H, 6.25;
N, 17.07.
6.1.5. Synthesis of 10-methoxy-5, 6-dihydro-triazolo[4,3-d]benzo[f]
[1,4]oxazepine (6)
6.1.7.3. 10-Butoxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4]oxazepine
A mixture of compound 5 (0.79 g, 3.8 mmol) and formic acid
(20 mL) was heated at 120 ꢀC for 4 h. After removing the excess
formic acid under reduced pressure, the residue was dissolved with
CH2Cl2 and washed with water. The CH2Cl2 layer was dried over
anhydrous MgSO4. Evaporation of the solvents gave a crude
product, which was purified by silica gel column chromatography
(dichloromethane: methanol ¼ 60:1) to a white solid 6.
(8c). M.p. 109e110 ꢀC, yield ¼ 82.8%. 1H NMR (CDCl3, 300 MHz),
d
0.98 (t, 3H, J ¼ 7.3 Hz, CH3), 1.44e1.54 (m, 2H, CH2), 1.71e1.81
(m, 2H, CH2), 4.02 (t, 2H, J ¼ 6.5 Hz, OeCH2), 4.43 (s, 4H,
NeCH2CH2eO), 6.92 (dd, 1H, J1 ¼ 8.9 Hz, J2 ¼ 2.8 Hz, Ar-H), 6.98 (d,
1H, J ¼ 8.9 Hz, Ar-H), 8.07 (d, 1H, J ¼ 2.8 Hz, Ar-H), 8.21 (s, 1H,
N]CH). IR (KBr) cmꢁ1: 1610 (C]N), 1266 (CeN), 1127 (NeN). MS
m/z 260 (M þ 1). Anal. Calcd. for C14H17N3O2: C, 64.85; H, 6.61;
N, 16.20. Found: C, 64.99; H, 6.68; N, 16.30.
M.p. 152e153 ꢀC, yield ¼ 83.2%. 1H NMR (CDCl3, 300 MHz),
d3.86
(s, 3H, OeCH3), 4.44 (s, 4H, NeCH2CH2eO), 6.91 (dd, 1H, J1 ¼ 9.0 Hz,
J2 ¼ 2.9 Hz, Ar-H), 6.98 (d,1H, J ¼ 9.0 Hz, Ar-H), 8.07 (d,1H, J ¼ 2.9 Hz,
Ar-H), 8.20 (s, 1H, N]CH). IR (KBr) cmꢁ1: 1615 (C]N), 1271 (CeN),
1132 (NeN). MS m/z 218 (M þ 1). Anal. Calcd. for C11H11N3O2: C,
60.82; H, 5.10; N, 19.34. Found: C, 60.94; H, 5.24; N, 19.27.
6.1.7.4. 10-Pentyloxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4]oxaze-
pine (8d). M.p. 85e86 ꢀC, yield ¼ 83.3%. 1H NMR (CDCl3, 300 MHz),
d
0.93 (t, 3H, J ¼ 6.9 Hz, CH3), 1.38e1.46 (m, 4H, (eCH2e)2),
1.73e1.82 (m, 2H, CH2), 4.02 (t, 2H, J ¼ 6.5 Hz, OeCH2), 4.43 (s, 4H,
NeCH2CH2eO), 6.92 (dd, 1H, J1 ¼ 8.9 Hz, J2 ¼ 2.7 Hz, Ar-H), 6.98
(d, 1H, J ¼ 8.9 Hz, Ar-H), 8.07 (d, 1H, J ¼ 2.7 Hz, Ar-H), 8.20 (s, 1H,
N]CH). IR (KBr) cmꢁ1: 1626 (C]N), 1281 (CeN), 1123 (NeN). MS
m/z 274 (M þ 1). Anal. Calcd. for C15H19N3O2: C, 65.91; H, 7.01; N,
15.37. Found: C, 66.13; H, 7.16; N, 15.19.
6.1.6. Synthesis of 5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4]
oxazepin-10-ol (7)
10-Methoxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4]oxazepine
(6) (2.00 g, 9.22 mmol) was dissolved in dichloromethane (60 mL).
BBr3 (46.1 mmol) was added dropwise to the solution and the
mixture was stirred at room temperature. After 4 h the mixture was
added slowly 20 mL ice cold water and allowed to stir for half
a hour. The resulting white precipitate was obtained by filtration.
6.1.7.5. 10-Hexyloxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4]oxaze-
pine (8e). M.p. 105e106 ꢀC, yield ¼ 80.7%. 1H NMR (CDCl3,
300 MHz),
d
0.91 (t, 3H, J ¼ 6.9 Hz, CH3), 1.33e1.46 (m, 6H,
M.p. 247e248 ꢀC, yield ¼ 90.4%. 1H NMR (CDCl3, 300 MHz),
d
4.53
(eCH2e)3), 1.73e1.81 (m, 2H, CH2), 4.02 (t, 2H, J ¼ 6.6 Hz, OeCH2),
(t, 2H, J ¼ 3.6 Hz, NeCH2), 4.71 (t, 2H, J ¼ 3.6 Hz, OeCH2), 6.99e7.01
4.43 (s, 4H, NeCH2CH2eO), 6.92 (dd, 1H, J1 ¼ 8.9 Hz, J2 ¼ 2.8 Hz,

X.-Q. Deng et al. / European Journal of Medicinal Chemistry 45 (2010) 3080e3086
3085
Ar-H), 6.98 (d, 1H, J ¼ 8.9 Hz, Ar-H), 8.08 (d, 1H, J ¼ 2.8 Hz, Ar-H),
8.21 (s, 1H, N]CH). IR (KBr) cmꢁ1: 1631 (C]N), 1284 (CeN), 1128
(NeN). MS m/z 288 (M þ 1). Anal. Calcd. for C16H21N3O2: C, 66.88; H,
7.37; N, 14.62. Found: C, 66.98; H, 7.54; N, 14.41.
6.1.7.13. 10-(3-Chlorobenzyloxy)-5, 6-dihydro-triazolo[4,3-d]benzo[f]
[1,4]oxazepine (8m). M.p. 138e140 ꢀC, yield ¼ 61.2%. 1H NMR
(CDCl3, 300 MHz), d4.44 (s, 4H, NeCH2CH2eO), 5.10 (s, 2H, OeCH2),
6.99e7.02 (m, 2H, Ar-H), 7.31e7.46 (m, 4H, Ar-H), 8.19 (s, 1H, Ar-H),
8.21 (s, 1H, N]CH). IR (KBr) cmꢁ1: 1618 (C]N), 1277 (CeN), 1135
(NeN). MS m/z 328 (M þ 1). Anal. Calcd. for C17H14ClN3O2: C, 62.30;
H, 4.31; N, 12.82. Found: C, 62.49; H, 4.20; N, 12.92.
6.1.7.6. 10-Heptyloxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4]oxaze
pine (8f). M.p. 100e101 ꢀC, yield
¼
71.1%. 1H NMR (CDCl3,
300 MHz),
d
0.91 (t, 3H, J ¼ 6.8 Hz, CH3), 1.32e1.47 (m, 8H,
(eCH2e)4), 1.75e1.82 (m, 2H, CH2), 4.03 (t, 2H, J ¼ 6.6 Hz, OeCH2),
4.44 (s, 4H, NeCH2CH2eO), 6.93 (dd, 1H, J1 ¼ 8.9 Hz, J2 ¼ 2.8 Hz, Ar-
H), 6.99 (d, 1H, J ¼ 8.9 Hz, Ar-H), 8.09 (d, 1H, J ¼ 2.8 Hz, Ar-H), 8.22
(s, 1H, N]CH). IR (KBr) cmꢁ1: 1633 (C]N),1287 (CeN),1119 (NeN).
MS m/z 302 (M þ 1). Anal. Calcd. for C17H23N3O2: C, 67.75; H, 7.69;
N, 13.94. Found: C, 67.91; H, 7.77; N, 13.78.
6.1.7.14. 10-(4-Chlorobenzyloxy)-5, 6-dihydro-triazolo[4,3-d]benzo[f]
[1,4]oxazepine (8n). M.p. 183e184 ꢀC, yield ¼ 66.5%. 1H NMR (CDCl3,
300 MHz), d4.44 (s, 4H, NeCH2CH2eO), 5.10 (s, 2H, OeCH2), 6.97e7.01
(m, 2H, Ar-H), 7.36 (d, 2H, J¼ 8.6Hz, Ar-H),7.40(d,2H, J¼ 8.6Hz, Ar-H),
8.20(s,1H, Ar-H), 8.21(s,1H, N]CH).IR(KBr)cmꢁ1:1623(C]N),1270
(CeN),1165 (NeN). MS m/z 328 (Mþ 1). Anal. Calcd. for C17H14ClN3O2:
C, 62.30; H, 4.31; N, 12.82. Found: C, 62.41; H, 4.46; N, 12.86.
6.1.7.7. 10-Octyloxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4]oxaze
pine (8g). M.p. 106e107 ꢀC, yield ¼ 73.6%. 1H NMR (CDCl3,
6.1.7.15. 10-(2-Bromobenzyloxy)-5, 6-dihydro-triazolo[4,3-d]benzo[f]
300 MHz),
d
0.88 (t, 3H, J ¼ 6.6 Hz, CH3), 1.28e1.44 (m, 10H,
[1,4]oxazepine (8o). M.p. 142e144 ꢀC, yield ¼ 68.9%. 1H NMR
(eCH2e)5), 1.72e1.79 (m, 2H, CH2), 3.99 (t, 2H, J ¼ 6.5 Hz, OeCH2),
4.42 (s, 4H, NeCH2CH2eO), 6.91 (dd, 1H, J1 ¼ 8.9 Hz, J2 ¼ 2.3 Hz, Ar-
H), 6.95 (d, 1H, J ¼ 8.9 Hz, Ar-H), 8.09 (d, 1H, J ¼ 2.3 Hz, Ar-H), 8.21
(s,1H, N]CH). IR (KBr) cmꢁ1: 1639 (C]N),1291 (CeN),1135 (NeN).
MS m/z 316 (M þ 1). Anal. Calcd. for C18H25N3O2: C, 68.54; H, 7.99;
N, 13.32. Found: C, 68.72; H, 7.87; N, 13.42.
(CDCl3, 300 MHz), d4.44 (s, 4H, NeCH2CH2eO), 5.17 (s, 2H, OeCH2),
6.98e7.02 (m, 2H, Ar-H), 7.17e7.60 (m, 4H, Ar-H), 8.21 (s, 1H, Ar-H),
8.24 (s, 1H, N]CH). IR (KBr) cmꢁ1: 1622 (C]N), 1264 (CeN), 1161
(NeN). MS m/z 372 (M þ 1). Anal. Calcd. for C17H14BrN3O2: C, 54.86;
H, 3.79; N, 11.29. Found: C, 54.97; H, 3.85; N, 11.16.
6.1.7.16. 10-(3-Bromobenzyloxy)-5, 6-dihydro-triazolo[4,3-d]benzo[f]
6.1.7.8. 10-Benzyloxy-5, 6-dihydro-triazolo[4,3-d]benzo[f][1,4]oxaze
[1,4]oxazepine (8p). M.p. 141e142 ꢀC, yield ¼ 73.3%. 1H NMR (CDCl3,
pine (8h). M.p. 149e151 ꢀC, yield ¼ 88.9%. 1H NMR (CDCl3,
300 MHz), d4.43 (s, 4H, NeCH2CH2eO), 5.08 (s, 2H, OeCH2),
300 MHz),
d
4.39 (s, 4H, NeCH2CH2eO), 5.09 (s, 2H, OeCH2),
6.98e7.02 (m, 2H, Ar-H), 7.23e7.62 (m, 4H, Ar-H), 8.17 (s, 1H, Ar-H),
8.20 (s, 1H, N]CH). IR (KBr) cmꢁ1: 1616 (C]N), 1266 (CeN), 1147
(NeN). MS m/z 372 (M þ 1). Anal. Calcd. for C17H14BrN3O2: C, 54.86;
H, 3.79; N, 11.29. Found: C, 55.03; H, 3.90; N, 11.21.
6.94e6.97 (m, 2H, Ar-H), 7.31e7.46 (m, 5H, Ar-H), 8.17 (s, 1H, Ar-H),
8.17 (s, 1H, N]CH). IR (KBr) cmꢁ1: 1601 (C]N), 1252 (CeN), 1135
(NeN). MS m/z 294 (M þ 1). Anal. Calcd. for C17H15N3O2: C, 69.61; H,
5.15; N, 14.33. Found: C, 69.77; H, 5.28; N, 14.13.
6.1.7.17. 10-(4-Bromobenzyloxy)-5, 6-dihydro-triazolo[4,3-d]benzo[f]
6.1.7.9. 10-(2-Fluorobenzyloxy)-5, 6-dihydro-triazolo[4,3-d]benzo[f]
[1,4]oxazepine (8q). M.p.187e188 ꢀC, yield ¼ 75.5%. 1H NMR (CDCl3,
[1,4]oxazepine (8i). M.p. 140e142 ꢀC, yield ¼ 57.4%. 1H NMR (CDCl3,
300 MHz), d4.43 (s, 4H, NeCH2CH2eO), 5.06 (s, 2H, O-CH2),
300 MHz),
d
4.44 (s, 4H, NeCH2CH2eO), 5.18 (s, 2H, OeCH2),
6.97e7.01 (m, 2H, Ar-H), 7.33 (d, 2H, J ¼ 8.2 Hz, Ar-H), 7.51 (d, 2H,
J ¼ 8.2 Hz, Ar-H), 8.17 (s, 1H, Ar-H), 8.19 (s, 1H, N]CH). IR
(KBr) cmꢁ1: 1609 (C]N), 1264 (CeN), 1149 (NeN). MS m/z 372
(M þ 1). Anal. Calcd. for C17H14BrN3O2: C, 54.86; H, 3.79; N, 11.29.
Found: C, 54.93; H, 3.72; N, 11.19.
6.98e7.01 (m, 2H, Ar-H), 7.06e7.56 (m, 4H, Ar-H), 8.21 (s, 1H, Ar-H),
8.24 (s, 1H, N]CH). IR (KBr) cmꢁ1: 1605 (C]N), 1266 (CeN), 1141
(NeN). MS m/z 312 (M þ 1). Anal. Calcd. for C17H14FN3O2: C, 65.59;
H, 4.53; N, 13.50. Found: C, 65.71; H, 4.64; N, 13.29.
6.1.7.10. 10-(3-Fluorobenzyloxy)-5, 6-dihydro-triazolo[4,3-d]benzo[f]
6.1.7.18. 10-(4-Methylbenzyloxy)-5, 6-dihydro-triazolo[4,3-d]benzo
[1,4]oxazepine (8j). M.p. 128e130 ꢀC, yield ¼ 72.5%. 1H NMR (CDCl3,
[f][1,4]oxazepine (8r). M.p. 164e166 ꢀC, yield ¼ 44.5%. 1H NMR
300 MHz),
d
4.42 (s, 4H, NeCH2CH2eO), 5.10 (s, 2H, OeCH2),
(CDCl3, 300 MHz), d2.36 (s, 3H, Ar-CH3), 4.42 (s, 4H, NeCH2CH2eO),
6.97e7.00 (m, 2H, Ar-H), 7.00e7.38 (m, 4H, Ar-H), 8.16 (s, 1H, Ar-H),
8.20 (s, 1H, N]CH). IR (KBr) cmꢁ1: 1609 (C]N), 1271 (CeN), 1137
(NeN). MS m/z 312 (M þ 1). Anal. Calcd. for C17H14FN3O2: C, 65.59;
H, 4.53; N, 13.50. Found: C, 65.65; H, 4.61; N, 13.33.
5.08 (s, 2H, O-CH2), 6.96e7.01 (m, 2H, Ar-H), 7.20 (d, 2H, J ¼ 7.8 Hz,
Ar-H), 7.34 (d, 2H, J ¼ 7.8 Hz, Ar-H), 8.20 (s, 1H, Ar-H), 8.20 (s, 1H,
N]CH). IR (KBr) cmꢁ1: 1607 (C]N), 1263 (CeN), 1152 (NeN). MS
m/z 308 (M þ 1). Anal. Calcd. for C18H17N3O2: C, 70.34; H, 5.58; N,
13.67. Found: C, 70.47; H, 5.66; N, 13.49.
6.1.7.11. 10-(4-Fluorobenzyloxy)-5, 6-dihydro-triazolo[4,3-d]benzo[f]
[1,4]oxazepine (8k). M.p.178e179 ꢀC, yield ¼ 72.4%. 1H NMR (CDCl3,
6.1.7.19. 10-(4-Methoxybenzyloxy)-5, 6-dihydro-triazolo[4,3-d]benzo
300 MHz),
d
4.43 (s, 4H, NeCH2CH2eO), 5.07 (s, 2H, OeCH2),
[f][1,4]oxazepine (8s). M.p. 140e141 ꢀC, yield ¼ 58.9%. 1H NMR
6.97e6.99 (m, 2H, Ar-H), 7.07 (dd, 2H, J1 ¼ 8.6 Hz, J2 ¼ 8.5 Hz, Ar-H),
7.43 (dd, 2H, J1 ¼ 8.6 Hz, J2 ¼ 5.6 Hz, Ar-H), 8.18 (s, 1H, Ar-H), 8.21 (s,
1H, N]CH). IR (KBr) cmꢁ1: 1607 (C]N), 1260 (CeN), 1155 (NeN).
MS m/z 312 (M þ 1). Anal. Calcd. for C17H14FN3O2: C, 65.59; H, 4.53;
N, 13.50. Found: C, 65.70; H, 4.67; N, 13.38.
(CDCl3, 300 MHz), d3.82 (s, 3H, OeCH3), 4.43 (s, 4H, NeCH2CH2eO),
5.05 (s, 2H, OeCH2), 6.97e7.01 (m, 2H, Ar-H), 6.92 (d, 2H, J ¼ 8.3 Hz,
Ar-H), 7.39 (d, 2H, J ¼ 8.3 Hz, Ar-H), 8.21 (s, 1H, Ar-H), 8.21 (s, 1H,
N]CH). IR (KBr) cmꢁ1: 1614 (C]N), 1273 (CeN), 1139 (NeN). MS
m/z 224 (M þ 1). Anal. Calcd. for C18H17N3O3: C, 66.86; H, 5.30;
N, 13.00. Found: C, 66.98; H, 5.41; N, 12.86.
6.1.7.12. 10-(2-Chlorobenzyloxy)-5, 6-dihydro-triazolo[4,3-d]benzo[f]
[1,4]oxazepine (8l). M.p. 131e132 ꢀC, yield ¼ 62.2%. 1H NMR (CDCl3,
6.2. Pharmacology
300 MHz),
d4.43 (s, 4H, NeCH2CH2eO), 5.19 (s, 2H, OeCH2),
6.97e7.00 (m, 2H, Ar-H), 7.28e7.68 (m, 4H, Ar-H), 8.22 (s, 1H, Ar-H),
8.22 (s, 1H, N]CH). IR (KBr) cmꢁ1: 1611 (C]N), 1271 (CeN), 1142
(NeN). MS m/z 328 (Mþ1). Anal. Calcd. for C17H14ClN3O2: C, 62.30;
H, 4.31; N, 12.82. Found: C, 62.44; H, 4.25; N, 12.89.
6.2.1. Anticonvulsant effects in the maximal electroshock seizure (MES)
test [25,26]
The MES test was carried out by the methods described in the
ADD of the National Institutes of Health (USA) [16,17]. Seizures

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X.-Q. Deng et al. / European Journal of Medicinal Chemistry 45 (2010) 3080e3086
were elicited with a 60 Hz alternating current of 50 mA intensity in
mice. The current was applied via corneal electrodes for 0.2 s.
Protection against the spread of MES-induced seizures was defined
as the abolition of the hind leg and tonic maximal extension
component of the seizure. At 30 min after the administration of the
compounds, the activities were evaluated in MES test. In phase-I
screening, each compound was administered at the dose levels of
30, 100, and 300 mg/kg for evaluating the preliminary anticon-
vulsant activity. For determination of the median effective dose
(ED50) the median toxic dose (TD50), the phase-II screening was
prepared. Groups of 10 mice were given a range of intraperitoneal
doses of the tested compound until at least three points were
established in the range of 10e90% seizure protection or minimal
observed neurotoxicity. From the plot of this data, the respective
ED50 and TD50 values, 95% confidence intervals, slope of the
regression line, and the standard error of the slope were calculated
by means of a computer program written at National Institute of
Neurological Disorders and Stroke.
for 2.5 h. The number of clonic seizures, tonic seizures, and the
lethality were recorded.
6.2.7. Bicuculline-induced seizures test [27]
At 30 min after the administration of compounds, the animals
(10 mice in one group) were given a subcutaneous dose of
2.7 mg/kg for Bicuculline (within 15e45 min after preparation
due to instability). Individual mice were then placed in isolation
cages and observed for at least 30 min for the presence or
absence of clonic seizures, and tonic seizures, and lethality was
also recorded.
Acknowledgment
This work was supported by the National Natural Science
Foundation of China (No. 30860340).
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