Nano-γ-Al2O3/SbCl5: An efficient catalyst for the synthesis of 2,3-dihydroperimidines

Article abstract of DOI:10.1039/c7ra13593a

Nano-γ-Al₂O₃/SbCl₅ as a new Lewis acid nano catalyst was synthesized and characterized by FTIR, XRD, FESEM, TEM, EDS, BET and TGA techniques. Nano-γ-Al₂O₃/SbCl₅ has been employed for synthe

Full text of DOI:10.1039/c7ra13593a

RSC Advances
View Article Online
View Journal | View Issue
PAPER
Nano-g-Al2O3/SbCl5: an efficient catalyst for the
synthesis of 2,3-dihydroperimidines†
Cite this: RSC Adv., 2018, 8, 6178
a
b
and Sepideh Saleha
*
Abdolhamid Bamoniri,
Bi Bi Fatemeh Mirjalili
Nano-g-Al2O3/SbCl5 as a new Lewis acid nano catalyst was synthesized and characterized by FTIR, XRD,
FESEM, TEM, EDS, BET and TGA techniques. Nano-g-Al2O3/SbCl5 has been employed for synthesis of 2-
substituted perimidines via reaction of naphthalene-1,8-diamine with various aldehydes at room
temperature under solvent-free conditions. This protocol proffers several benefits including high yields,
easy workup, short reaction times and simple reaction conditions.
Received 22nd December 2017
Accepted 31st January 2018
DOI: 10.1039/c7ra13593a
rsc.li/rsc-advances
applied as a support of industrial divers' types of reaction and
1. Introduction
as
as a support of
its potent interaction with metals and metal oxides
a
support for metals. Al2O3 is very repeatedly applied
catalysts for its mechanical intensity
also
that
Perimidines exhibit a diverse range of biological activities; such
as antibacterial, antifungal, anti-inammatory and anti-
tumor.1–6 It was of interest to explore the suitability of some
perimidines derivatives as potential DNA-intercalating ligands.7
A synthetic method for the preparation of perimidines is the
condensation reaction of 1,8-diaminonaphthalene with various
carbonyl groups.8–10 However, most of these methods suffers of
signicant side reaction, low yield and have cumbersome work-
up procedures.
provides high propagation of the supported compounds. As for
the surface properties, alumina is commonly considered as
acidic rather than basic, but basic positions coexist.25 Alumina
is a main material for usages in ultraltration of salts, as an
automobile exhaust catalyst, and in petroleum purication.
Porous g-alumina with equal channels, high surface area, and
slender pore-size repartition possesses conjunction better
physicochemical properties. However, the manufacturing of
ordered and thermally constant porous alumina is demon-
strated due to its susceptibility for hydrolysis and phase
transition-induced demolition of ordered pore structure.26
Here in, we wish to report a simple method for the synthesis
of nano-g-Al2O3/SbCl5 and its usage in the synthesis of 2,3-
dihydroperimidines under solvent-free grinding condition at
room temperature.
Some catalysts are reported for perimidine synthesis such as
zeolite,11 CMK-5-SO3H,12 BiCl3,13 BF3$H2O,14 Yb(OTf)3,15
Cu(NO3)2$6H2O,16 FePO4,17 Fe3O4/SiO2/(CH2)3N+Me3Br3
,
ꢀ
18
[BTBA]Cl–FeCl3,19 nano-silica sulfuric acid,20 amberlyst 15
(ref. 21) and molecular iodine.22
Antimony pentachloride (SbCl5), a thin and fuming liquid, is
applied in industry and organic synthesis. Where of, antimony
pentachloride is a liquid with a great specic gravity that
fumigates in air and reacts with the humidity to form HCl, the
tactility and the usability of SbCl5 as a liquid form is arduous
and the supported form is really preferable. It has been
acclaimed that the supported SbCl5 is a solid superacid. SbCl5 is
used immensely in organic synthesis as a Lewis acid for
elevating a variety of organic reactions.23 Solid-acid catalysts are
commonly classied by their Brønsted and/or Lewis acidity, the
intensity and number of these positions, and the morphology of
the support. The synthesis of net Brønsted and net Lewis acid
catalysts attracts a major degree of academic concern.24
Alumina (Al2O3) is applied both as a catalyst for divers types of
reaction and as a support for metals. Al2O3 is very repeatedly
2. Experimental
2.1 Material and methods
All compounds were purchased from Fluka and Merck chemical
company and used without any additional purication. Fourier
transform infrared (FT-IR) spectra were run on a Nicolet Magna 550
spectrometer. A Bruker (DRX-400 Avance) NMR was used to record
the 1H-NMR and 13C-NMR spectra. XRD pattern using Philips
Xpert MP diffractometer (Cu Ka, radiation, k ¼ 0.154056 nm) was
achieved. FE-SEM was obtained on a Mira Tescan. Transmission
electron microscope (TEM) was recorded on a Philips-CM
120-with LaB6 cathode instrument on an accelerating voltage
of 120 kV. The thermal gravimetric analysis (TGA) was done with
“STA 504” instrument. Energy-dispersive X-ray spectroscopy
(EDS) of SbCl5/nano-g-Al2O3 was measured by EDS instrument,
Phenom pro X. BET surface area analysis of catalyst was done
with Micrometrics, Tristar II 3020 analyser.
aDepartement of Org. Chem., Faculty of Chem., University of Kashan, Kashan, I. R.
Iran. E-mail: bamoniri@kashanu.ac.ir
bDepartment of Chem., College of Sci., Yazd University, Yazd, I. R. Iran
† Electronic supplementary information (ESI) available. See DOI:
10.1039/c7ra13593a
6178 | RSC Adv., 2018, 8, 6178–6182
This journal is © The Royal Society of Chemistry 2018

View Article Online
Paper
RSC Advances
until no more sulfate ions were detected in the washings.
Following the aging step, NaOH (100 ml, 1 M) was added to
a beaker containing Al(OH)3 (20 g) to produce NaAl(OH)4. Then
PEG 4000 (0.3%) was added to solution and it was neutralized
with HCl (0.1 M), to pH 8 until Al(OH)3 produced again.
The obtained precipitate ltered and washed with distilled
2.2 Preparation of nano-g-Al2O3
NaOH (600 ml, 1 M), was added drop-wise to a slurry containing
Al2(SO4)3$18H2O (66 g). The mixture was stirred at room
temperature. The resulted suspension was ltered to obtain the
white solid Al(OH)3. Then solid were washed with distilled water
ꢁ
water. The as-dried solid was calcined in the furnace at 800 C
for 3 hours through atmospheric air to produce nano-g-Al2O3
powder.
2.3 Preparation of nano-g-Al2O3/SbCl5
To a mixture of nano-g-Al2O3 (1 g) and CH2Cl2 (10 ml), SbCl5
(0.5 ml) was added drop wise in the well ventilated hood. The
resulting suspension was stirred for 1 hour at room tempera-
ture, ltered, washed with CH2Cl2, and dried at room
temperature.
Fig. 1 FT-IR spectra of (a) nano-g-Al2O3 and (b) nano-g-Al2O3/SbCl5.
Fig. 3 XRD patterns of nano-g-Al2O3/SbCl5.
Fig. 4 EDS analysis diagram of SbCl5/nano-g-Al2O3.
Fig. 5 Thermal gravimetric analysis (TG-DTA) pattern of nano-g-
Fig. 2 TEM (a) and FESEM (b) images of nano-g-Al2O3/SbCl5.
Al2O3/SbCl5.
This journal is © The Royal Society of Chemistry 2018
RSC Adv., 2018, 8, 6178–6182 | 6179

View Article Online
RSC Advances
Paper
a mortar with a pestle for a few minutes to obtain a homoge-
neous mixture. Aer completed conversion as indicated by TLC,
10 ml of ethanol was added then the heterogeneous catalyst was
ltered. By adding crushed ice to ltrate, the pure products were
obtained as white solids.
3. Results and discussion
In continuation of our investigation on the utilization of solid
acids in organic synthesis, we have synthesized nano-g-Al2O3/
SbCl5 as a new nano catalyst and studied its efficiency in the
synthesis of 2,3-dihydroperimidines at room temperature under
grinding conditions.
For exploration of the structure of nano-g-Al2O3/SbCl5, we
have studied FT-IR spectra of nano-g-Al2O3 and nano-g-Al2O3/
SbCl5 (Fig. 1). In nano-g-Al2O3 FT-IR spectrum, the band in the
region of 500–1000 cmꢀ1 is attributed to the stretching vibra-
tions of the (Al–O) bond in g-Al2O3 (Fig. 1). In nano-g-Al2O3/
SbCl5 spectrum, in addition to g-Al2O3 signal, two additional
band at 701 show binding of SbCl5 to g-Al2O3.
The FESEM and TEM images of the nano-g-Al2O3/SbCl5 are
demonstrated in Fig. 2. They exhibit disordered spherical shape
for nano particles below 50 nm.
The X-ray diffraction (XRD) pattern of nano-g-Al2O3/SbCl5 is
exhibited in (Fig. 3). The signals at 2q equal to 37 (c), 45 (d) and
67 (e) are displayed nano-g-Al2O3 structure. According to XRD
pattern, the two additional signals at 2q equal to 28 (a) and 32
(b) respectively, are shown the presentment of bonded Sb to
nano-g-Al2O3 (Fig. 3).
The energy-dispersive X-ray spectroscopy (EDS) of the
synthesized catalyst is displayed in Fig. 4. EDX pattern obviously
approbates the presence of the anticipated elements in the
construction of this catalyst and corroborated supporting of
SbCl5 on nano-g-Al2O3. The elemental compositions of nano-g-
Al2O3/SbCl5 were found to be 58.7, 30.8 and 8.1% for O, Al and
Sb, respectively.
Fig. 6 Nitrogen adsorption isotherm at 77 K of nano-g-Al2O3/SbCl5.
2.4 General procedure for the preparation of 2,3-
dihydroperimidines
Thermal gravimetric analysis (TG-DTA) template of SbCꢁl5/
ꢁ
nano-g-Al2O3 was discovered by heating from 20 C to 780 C
and then cooling until 165 ꢁC (Fig. 5). The catalyst is stable until
390 ꢁC and only 10.5% of its weight was reduce due to the
Naphthalene-1,8-diamine (1 mmol), aromatic aldehydes
(1 mmol) and nano-g-Al2O3/SbCl5 (0.1 g) were grounded in
Table 1 Condensation of 4-chlorobenzaldehyde and 1,8-diaminonaphthalene under various conditionsa
Entry
Catalyst
Solvent
Temp (ꢁC)
Time (min)
Yield%
1
2
3
4
5
6
7
8
Zeolite
Ethanol
—
Ethanol
—
—
—
—
—
—
r. t.
80
2700
15
420
60
60
60
30
15
15
15
40 (ref. 11)
95 (ref. 18)
90 (ref. 17)
Fe3O4/SiO2/(CH2)3N+Me3Br3
FePO4
ꢀ
r. t.
r. t.
r. t.
r. t.
r. t.
r. t.
r. t.
r. t.
r. t.
r. t.
Nano-g-Al2O3/SbCl5 (0.005 g)
Nano-g-Al2O3/SbCl5 (0.008 g)
Nano-g-Al2O3/SbCl5 (0.01 g)
Nano-g-Al2O3/SbCl5 (0.08 g)
Nano-g-Al2O3/SbCl5 (0.1 g)
Nano-g-Al2O3/SbCl5 (0.14 g)
Nano-g-Al2O3/SbCl5 (0.16 g)
Nano-g-Al2O3/SbCl5 (0.20 g)
Nano-g-Al2O3/SbCl5 (0.25 g)
20
30
35
50
70
80
95
95
95
9
10
11
12
—
—
—
15
15
a
1,8-Diaminonaphthalene (1 mmol), and 4-chlorobenzaldehyde (1 mmol) were used.
6180 | RSC Adv., 2018, 8, 6178–6182
This journal is © The Royal Society of Chemistry 2018

View Article Online
Paper
RSC Advances
removal of catalyst humidity. The char yield of the catalyst in
390 ꢁC is 89.5%. According to the TG-DTA pattern of nano-g-
Al2O3/SbCl5 and our discussion, it was disclosed that this
catalyst is appropriate for the advancement of organic reactions
until 400 ꢁC.
The BET N2 adsorption method is applied to measure the
surface area. The BET surface areas is assigned as 92.503 m2 gꢀ1
.
The N2 adsorption isotherm of catalyst is described in Fig. 6.
Inductive coupled plasma (ICP) analysis have determined the
existence 200 mg of Sb in 1 g of catalyst.
Aer characterization of catalyst, we have investigated cata-
lytic activity of nano-g-Al2O3/SbCl5 for the synthesis of 2,3-
dihydroperimidines derivatives. For optimization of the reac-
tion reservations, 1,8-diaminonaphthalene (1 mmol), and 4-
chlorobenzaldehyde (1 mmol) were used as model reactants
under solvent-free conditions (Table 1). The best resultant
based on yield and time of the reaction was afforded with 0.16 g
of nano-g-Al2O3/SbCl5. At rst, in order to show the unrivalled
catalytic behaviour of nano-g-Al2O3/SbCl5 and to contrast its
activity with other catalysts. Also, Table 1, shows the perfor-
mance of our nano-catalyst in the preparation of 2,3-dihy-
droperimidines contrast to that of other reported methods.
Using the optimized reaction provisions, the reactions of
various substituted benzaldehydes with naphthalene-1,8-
diamine were studied (Scheme 1, Table 2).
Scheme 2 Proposed mechanism of the SbCl5/nano-g-Al2O3-cata-
lysed synthesis of 2,3-dihydroperimidines.
a catalytic amount of nano-g-Al2O3/SbCl5. In general, with
electron-drawing substituents in the aromatic benzaldehydes,
increased yields of products were generated, whereas the affect
is reversed with electron donating substituents. However, the
variations in the yields were little.
As displayed in Table 2, a number of aromatic aldehydes
bearing electron withdrawing groups and electron-donating
groups were further subjected to reaction employing
A plausible pathway for the preparation of 2,3-dihydroper-
imidines in the presence of nano-g-Al2O3/SbCl5 is revealed in
Scheme 2. Nucleophilic attack of 1,8-diamino naphthalene 2 to
SbCl5-activated aldehyde 1 generated intermediate 3. In situ
dehydration of compound 4 and nucleophilic attack of the
second amino group to SbCl5-activated imine intermediate 5
afforded intermediate 6 to produce the compound 7.
Scheme 1 Synthesis of 2,3-dihydroperimidines.
4. Conclusions
In conclusion, nano-g-Al2O3/SbCl5 was successfully synthe-
sized, characterized and applied for the synthesis of 2,3-dihy-
droperimidine derivatives. Short reaction times, high
conversions, clean reaction proles, simple work-up, avail-
ability and high activity of catalyst, make this method suitable
for many acid catalysed organic reactions.
Table 2 Synthesis of 2-substituted perimidines catalyst by nano-g-
Al2O3/SbCl5
a
Entry
R
Product
Time (min)
Yieldb (%)
1
2
3
4
5
6
7
8
4-Cl
2-NO2
3-NO2
4-NO2
4-COOH
4-NMe2
4-OMe
2,4-OMe2
2,3-Cl2
2,3-OMe2
3,4-OMe2
3a
3b
3c
3d
3e
3f
3g
3h
3i
14
15
13
15
20
20
15
16
14
15
13
95
90
95
93
80
90
85
80
85
80
85
Conflicts of interest
There are no conicts to declare.
9
10
11
3j
3k
Acknowledgements
a
1,8-Diaminonaphthalene (1 mmol), aldehyde (1 mmol) and nano-g-
b
The authors are grateful to University of Kashan for supporting
this work by Grant No. (159189/50).
Al2O3/SbCl5 (0.16 g) were used. Isolated yield.
This journal is © The Royal Society of Chemistry 2018
RSC Adv., 2018, 8, 6178–6182 | 6181

View Article Online
RSC Advances
Paper
13 J. Zhang and S. Zhang, Synth. Commun., 2007, 37, 2615–2624.
14 G. K. S. Prakash, F. Paknia, A. Narayan, T. Mathew and
G. A. Olah, J. Fluorine Chem., 2013, 152, 99–105.
15 S. l. Zhang and J. M. Zhang, Chin. J. Chem., 2008, 26, 185–
189.
16 A. Mobinikhaledi and P. J. Steel, Synth. React. Inorg., Met.-
Org., Nano-Met. Chem., 2009, 39, 133–135.
17 F. K. Behbahani and F. M. Golchin, Journal of Taibah
University for Science, 2016, 11, 85–89.
References
1 P. Sharma, N. Rane and V. K. Gurram, Bioorg. Med. Chem.
Lett., 2004, 14, 4185–4190.
2 N. Ingarsal, G. Saravanan, P. Amutha and S. Nagarajan, Eur.
J. Med. Chem., 2007, 42, 517–520.
3 S. M. Sondhi, N. Singh, M. Johar and A. Kumar, Bioorg. Med.
Chem., 2005, 13, 6158–6166.
4 M.
Dzieduszycka,
S.
Martelli,
M.
Arciemiuk,
18 A. Farrokhi, K. Ghodrati and I. Yavari, Catal. Commun., 2015,
63, 41–46.
M. M. Bontemps-Gracz, A. Kupiec and E. Borowsk, Bioorg.
Med. Chem., 2002, 10, 1025–1035.
19 K. Bahrami and S. Saleh, Synth. React. Inorg., Met.-Org., Nano-
Met. Chem., 2016, 46, 852–856.
5 T. A. Farghaly and H. K. Mahmoud, Arch. Pharm. Chem. Life
Sci., 2013, 346, 392–402.
20 A. Mobinikhaledi, H. Moghanian and F. Sasani, Int. J. Green
Nanotechnol., 2010, 2, 47–52.
6 T. A. Farghaly, E. M. H. Abbas, K. M. Dawood and T. B. A. El-
Naggar, Molecules, 2014, 19, 740–755.
21 V. V. Patil and G. S. Shankarling, Catal. Commun., 2014, 57,
138–142.
7 J. M. Herbert, P. D. Woodgate and W. A. Denny, J. Med.
Chem., 1987, 30, 2081–2086.
22 A. Mobinikhaledi, M. A. Bodaghi Fard, F. Sasani and
M. A. Amrollahi, Bulg. Chem. Commun., 2013, 45, 353–356.
23 B. Sadeghi and M. Baradaran, Iran. J. Org. Chem., 2010, 2,
431–435.
24 K. Wilson and J. H. Clark, Pure Appl. Chem., 2000, 72, 1313–
1319.
25 H. Hattoni and Y. One, Solid acid catalysis from fundamentals
to applications, Pan Stanford Publishing, Singapore, 2015.
26 H. Li, L. Zhang, H. Dai and H. He, Inorg. Chem., 2009, 48,
4421–4434.
8 I. Yavari, M. Adib, F. Jahani-Moghaddam and
H. R. Bijanzadeh, Tetrahedron, 2002, 58, 6901–6908.
9 A. Mobinikhaledi, M. A. Amrollahi, N. Foroughifar and
H. F. Jirandehi, Asian J. Chem., 2005, 17, 2411–2414.
10 A. Mobinikhaledi, N. Foroughifar and R. Goli, Phosphorus,
Sulfur, Silicon Relat. Elem., 2005, 180, 2549–2554.
11 A. Mobinikhaledi, N. Foroughifar and N. Basaki, Turk. J.
Chem., 2002, 33, 555–560.
12 H. Alinezhad and M. Zare, J. Chil. Chem. Soc., 2013, 58, 1840–
1841.
6182 | RSC Adv., 2018, 8, 6178–6182
This journal is © The Royal Society of Chemistry 2018