Ultrasonic accelerated efficient synthesis of aminobenzochromenes using Ag2Cr2O7 nanoparticles as a reusable heterogeneous catalyst

Article abstract of DOI:10.1002/jhet.3915

Ag₂Cr₂O₇ nanoparticles were found to be an exceedingly effective catalyst for the mild and green synthesis of aminobenzochromenes. The reaction was performed under ultrasonic irradiation as an innocuous tool and in water a

Full text of DOI:10.1002/jhet.3915

Received: 9 December 2019
DOI: 10.1002/jhet.3915
Revised: 8 January 2020
Accepted: 14 January 2020
A R T I C L E
Ultrasonic accelerated efficient synthesis
of aminobenzochromenes using Ag Cr O
2
2 7
nanoparticles as a reusable heterogeneous catalyst
Mitra Ebrahimi | Shahrzad Abdolmohammadi
| Reza Kia-Kojoori
Department of Chemistry, East Tehran
Abstract
Branch, Islamic Azad University,
Tehran, Iran
Ag Cr O nanoparticles were found to be an exceedingly effective catalyst for
2 2 7
the mild and green synthesis of aminobenzochromenes. The reaction was
performed under ultrasonic irradiation as an innocuous tool and in water as a
green solvent at room temperature. This method encompasses several sustain-
able and economic benefits.
Correspondence
Shahrzad Abdolmohammadi, Department
of Chemistry, East Tehran Branch,
Islamic Azad University, P.O. Box
18735-138, Tehran, Iran.
Email: abdolmohamadi_sh@yahoo.com;
s.abdolmohamadi@iauet.ac.ir
Funding information
Islamic Azad University; Research
Council
1
| INTRODUCTION
practice of green chemistry because it is safe, nontoxic,
nonflammable or corrosive, cost-effective, and readily
[
18–21]
Aminochromenes form a significant type of biodegradable
available.
Furthermore, an efficient and green tool
organic compounds found as the principal components in
for organic reactions is to use ultrasound technique as a
nonconventional energy source can provide a range of
benefits such as shorter reaction times, easier operation,
[1]
variety of natural products and medicinal agnates. More-
over, these compounds have been successfully utilized for
[2]
[22–25]
the preparation of cosmetics and pigments . In addition,
fused chromenes are major parts of pharmacologically active
compounds with a wide range of interesting biologically
and improved yields of pure products.
According to the above mentioned potentialities
of aminochromenes, several synthetic protocols
involving the condensation between aromatic aldehydes,
malononitrile, and activated phenol, or 4-hydroxycoumarin
[
3]
[4,5]
[6]
properties like antiviral, antimicrobial,
anticancer,
[7]
[8]
[9]
antiproliferative, mutagenicity, sex pheromonal, anti-
[10,11]
influenza virus,
and central nervous system active
in the presence of different catalysts, have been encountered
[12]
[26–39]
drugs.
led to them.
While most of these synthetic protocols
Currently, nanostructured metal salts are generally
used as eco-efficient heterogeneous catalysts for various
organic transformations, due to their pronounced fea-
tures such as optimum porous size and high ratio of
afforded good yields, these procedures take into
account limitations such as long reaction times, harsh
reaction conditions, use of toxic solvents, and often
expensive catalysts seem less suitable. This paper pre-
sents a novel, efficient, and green procedure to pro-
duce a variety of aminobenzochromenes (4 and 6) via a
three-component reaction of aromatic aldehydes (1),
malononitrile (2), and α-naphthol (3) or β-naphthol (5)
catalyzed by Ag Cr O NPs in aqueous media under
[
13–17]
their surface area versus their volume.
The silver
dichromate nanoparticles (Ag Cr O NPs) can be con-
2
2
7
sidered to be one of the effective nanocatalyst, which
presume to display economically and environmentally
friendly benefits.
2
2
7
Performing the organic reactions in water as an ideal
green medium has gained increasing interest for proper
ultrasonic irradiation at room temperature conditions
(Scheme 1).
J Heterocyclic Chem. 2020;1–7.
wileyonlinelibrary.com/journal/jhet
© 2020 Wiley Periodicals, Inc.
1

2
EBRAHIMI ET AL.
2
| RESULTS AND DISCUSSION
After preparation of the catalyst, optimization experi-
ment was carried out by reacting of α-naphthol (3) with
4-bromobenzaldehyde (1b) and malononitrile (2) as
model substrates in the molar ratio of 1:1:1.2 to afford the
desired 3-amino-1-(4-bromophenyl)-1H-benzo[f]chromen-
2-yl cyanide (4b) under various reaction conditions.
The Ag Cr O NPs were prepared through a simple and
adaptable method reported by Salavati-Niasari et al.
The scanning electron microscopic (SEM) image of the
Ag Cr O NPs was given in Figure 1. The SEM image
2
2 7
[
40]
2
2 7
indicates the formation of bundles nanorods shape
nanoparticles with the average particle size of about
Initial endeavor on the catalytic potential of the
Ag Cr O NPs in comparison with other acid and base
2
2 7
4
0 nm (Figure 1).
catalysts revealed that 15 mol% of Ag Cr O NPs can be
2 2 7
The energy dispersive X-ray (EDS) spectroscopic anal-
considered to give the best results in water at room tem-
perature and under ultrasonic irradiation at power of
60 W (Table 1).
ysis of the as-prepared Ag Cr O NPs was also performed
2
2 7
using EDS equipped onto SEM. Quantitative EDS analysis
proved that Ag, Cr, and S are the main elemental compo-
nents (Figure 2). The appearance of sulphur element in
this spectrum ascribed to the SDS adsorbed on the
nanoparticles.
In continuation, to evaluate the effect of the reaction
media, the same reaction was performed in several
organic solvents including, EtOH, CH Cl , CH CN, and
2
2
3
DMF. As shown in Table 2, the promising results were
In the FTIR spectrum (Figure 3) of Ag Cr O NPs, a
obtained in H O.
2
2
7
1
2
−
characterization peak was observed at 886 cm , which
can be assigned to the Cr–O stretching vibrations. The
peak at 3436 cm− is also attributed to the O–H
stretching vibrations of water molecules adsorbed on the
surface of Ag Cr O NPs. The very weak peaks at 2928,
Furthermore, the power of ultrasonic irradiation was
also explored (Table 3). However, it was found that the
power of 60 W was favorable for this reaction. It is
1
2
2 7
−
1
2
853, and 1092 cm are corresponded to the C–H and S–
O stretching bonds of SDS.
The structure of Ag Cr O NPs was further confirmed
2
2 7
by the XRD analysis (Figure 4). All the reflection peaks
corresponded to the Ag Cr O NPs, which can be in
2
2 7
agreement with the basis of JCPDS file No. 01-0963.
The grain size of about 39 nm for the particle-like
nanostructure of Ag Cr O NPs could be also calculated
2
2 7
using full width at half the maximum (FWHM) through
Debye-Scherrer formula according to the following
equation:
D = 0.9λ/Bcosθ,
where 0.9 is the shape factor, λ is the wavelength of
X-ray (0.154 nm), B is the line broadening at half the
maximum intensity (FWHM) in radians (0.004), and θ is
the Braggs angle in radians (15.5).
2 2 7
FIGURE 1 SEM images of the Ag Cr O NPs
SCHEME 1 Synthesis of aminobenzochromenes using
Ag
2
Cr
2
O
7
NPs [Color figure can be viewed at wileyonlinelibrary.com]
2 2 7
FIGURE 2 EDS analysis of Ag Cr O NPs

EBRAHIMI ET AL.
3
TABLE 1 Screening for the efficiency of Ag
2 2 7
Cr O NPs as
catalyst for the synthesis of 3-amino-1-(4-bromophenyl)-1H-benzo
[f]chromen-2-yl cyanide (4b)
a,b
Entry
Catalyst (mol %)
Time (min)
Yield (%)
1
2
3
4
5
6
No catalyst
12
10
10
7
Trace
73
Ag
Ag
Ag
2
2
2
Cr
Cr
Cr
2
2
2
O
O
7
7
7
NPs (10%)
NPs (15%)
NPs (20%)
95
O
96
c
p-TsOH (15 mol%)
10
10
82
d
DAHP (15 mol%)
78
a
FIGURE 3 FTIR spectrum of Ag
be viewed at wileyonlinelibrary.com]
2
Cr
2
O
7
NPs [Color figure can
Isolated yield.
b
Reaction conditions: A mixture of 4-bromobenzaldehyde (1 mmol),
malononitrile (1.2 mmol), and α-naphthol (1 mmol), in H O (3 mL) was
2
kept at room temperature under ultrasonic irradiation at power of 60 W.
c
p-TsOH: p-Toluenesulfonic acid.
d
DAHP: Diammonium hydrogen phosphate.
TABLE 2 The solvent effect on the synthesis of 3-amino-1-
(
4-bromophenyl)-1H-benzo[f]chromen-2-yl cyanide (4b)
a,b
Entry
Solvent
Time (min)
Yield (%)
1
2
3
4
6
H
2
O
10
15
20
15
20
95
88
74
83
87
EtOH
CH
CH
2
3
Cl
2
FIGURE 4 XRD spectra of Ag
2
Cr
2
O
7
NPs
CN
c
DMF
a
noteworthy that when the same reaction was carried out
without ultrasound at room temperature, a low yield of
product was found with prolonged reaction.
Isolated yield.
b
Reaction conditions: A mixture of 4-bromobenzaldehyde (1 mmol),
malononitrile (1.2 mmol), α-naphthol (1 mmol), and Ag Cr NPs
64.8 mg, 15 mol%) in solvent (3 mL) was kept at room temperature under
2
2 7
O
(
After this preliminary work, we proceeded to confirm
the generality of the mentioned reaction, some aryl alde-
hydes were selected to react with malononitrile and
α-naphthol or β-naphthol under the above optimized
conditions. All the reactions proceeded smoothly, and a
number of 3-amino-1-aryl-1H-benzo[f]chromen-2-yl cya-
nides 4(a-f) and 2-amino-4-aryl-4H-benzo[h]chromen-
ultrasonic irradiation at power of 60 W.
c
DMF: Dimethylformamide.
TABLE 3 Optimization of the power of ultrasonic irradiation
for the synthesis of of 3-amino-1-(4-bromophenyl)-1H-benzo[f]
chromen-2-yl cyanide (4b)
a,b
Entry
Power (W)
Time (min)
Yield (%)
3
-yl cyanides 6(a-f) were obtained in good to excellent
yields (Table 4). The structures of the products were
established by IR, H NMR, and C NMR spectral data
and by elemental analyses.
1
2
3
4
55
60
70
—
15
91
95
93
62
1
13
10
10
In addition, the recyclability of the heterogeneous
nanocatalyst was also examined. The results obtained
indicated that the recovered catalyst through a simple
manner as described in the general procedure can be
reused for seven additional times in subsequent reactions
under optimized reaction conditions. Yields of the prod-
uct decreased only slightly after five time's reuse of cata-
lyst (Figure 5).
240
a
Isolated yield.
b
Reaction conditions: A mixture of 4-bromobenzaldehyde (1 mmol),
malononitrile (1.2 mmol), α-naphthol (1 mmol), and Ag Cr NPs
64.8 mg, 15 mol%) in H O (3 mL) was kept at room temperature under
different power of ultrasonic irradiation.
2
2 7
O
(
2
A plausible mechanism for this catalytic reaction is
outlined in Scheme 2. The Ag Cr O NPs is an effective
acid-base bifunctional catalyst for the formation of alkene
9, readily prepared in situ from Knoevenagel condensa-
tion of aryl aldehyde 1 and malononitrile 2, which pro-
ceeds via intermediates 7 and 8. It is proposed that the
2
2 7

4
EBRAHIMI ET AL.
TABLE 4 Synthesis of
aminobenzochromenes 4(a-f) and 6(a-f)
ꢀ
M.p ( C)
a,b
Product
Ar
Compound 3 or 5
Yield (%)
Obsd.
Lit.
catalyzed by Ag
irradiation
2 2 7
Cr O NPs ultrasonic
4
4
4
4
4
4
6
6
6
6
6
6
a
b
c
d
e
f
C
6
H
5
3
3
3
3
3
3
5
5
5
5
5
5
92
95
94
88
87
94
91
93
93
85
86
92
211–213
237–239
219–220
255–257
250-252
240–242
285-287
230-232
234-236
288-290
283-284
213-215
208–210 [26]
240-242 [26]
218–222 [31]
258–260 [31]
250-253 [31]
239-241 [26]
287-288 [26]
227-229 [26]
235-238 [26]
285–287 [31]
280-282 [31]
217-219 [31]
4-Br-C
3-Cl-C
4-CN-C
3-OH-C
3-NO -C
6 4
H
6
H
4
6
H
4
6
H
4
2
6 4
H
a
b
c
d
e
f
6 5
C H
4-Br-C
3-Cl-C
4-CN-C
3-OH-C
3-NO -C
6 4
H
6
H
4
6
H
4
6
H
4
2
6 4
H
a
Isolated yield.
b
Reaction conditions: A mixture of aryl aldehyde (1 mmol), malononitrile (1.2 mmol), α-naphthol or
β-naphthol (1 mmol), and Ag Cr NPs (64.8 mg, 15 mol%) in H O (3 mL) was kept at room temperature
in water under ultrasonic irradiation at power of 60 W.
2
2
O
7
2
determined on Electrothermal 9100 apparatus. IR spectra
were recorded using ABB FT-IR (FTLA 2000) spectrome-
1
13
ter. H NMR and C NMR spectra were obtained on
Bruker DRX-300 AVANCE spectrometer at 500 and
125 MHz, respectively, using TMS as internal standard and
[
D ]DMSO as solvent. Elemental analyses were carried out
6
using a Foss-Heraeus CHN-O-Rapid analyzer. Powder X-ray
diffraction data were determined on a Rigaku D-max C III,
X-ray Diffractometert using Cu Kα radiation (λ = 1.54 Å).
The microscopic morphology of the catalyst was revealed
using scanning electron microscope (SEM, Philips,
XL-30) equipped with energy dispersive X-ray analysis
system (EDS).
FIGURE 5 Recyclability of the heterogeneous nanocatalyst
Color figure can be viewed at wileyonlinelibrary.com]
[
Ag Cr O NPs is also participated in the next step in
3.2 | Synthesis of Ag Cr O NPs
2
2
7
2
2 7
which α-naphthol 3 ads to alkene 9 in a Michael type
addition to generate intermediate 10. The cyclization of
At first, a pre-prepared solution of sodium salicylate
(2 mmol) in 40 mL of distilled water was added dropwise
1
0 gives product 4 after tautomerization of intermedi-
ate 11. The formation of product 6 is similarly to occur
via a tandem Kenoevenagel-Michael condensation as
that was explained in Scheme 2, for the formation of
product 4.
into a magnetically stirred mixture of AgNO (2 mmol) in
3
40 mL of distilled water. The obtained mixture was then
ꢀ
vigorous stirring by magnetic stirrer at 80 C for about
30 minutes. Afterwards, the produced precursor silver(I)
salicylate, [Ag(HSal)], as a white precipitate was filtered
and washed with distilled water and ethanol several times
to remove impurities. At the next step, precursor silver(I)
salicylate, [Ag(HSal)] (4 mmol), and sodium dodecyl sulfate
(SDS) (0.05 g) as shape controller were dissolved in
3
3
| EXPERIMENTAL
.1 | Material and methods
5
0 mL of distilled water. Subsequently, a previously pre-
All chemicals used in this work were purchased from
Merck and Fluka with high purity. Melting points were
pared solution of (NH ) Cr O (2 mmol) in 20 mL of dis-
tilled water was added dropwise to the above mixture.
4
2
2
7

EBRAHIMI ET AL.
5
SCHEME 2 Plausible mechanism
for the synthesis of 3-amino-1-aryl-1H-
benzo[f]chromen-2-yl cyanide in the
2 2 7
presence of Ag Cr O NPs
The mixture was left stirring at room temperature for
0 minutes. Finally, the resulted precipitate of Ag Cr O
7
3.3.1 | 3-Amino-1-phenyl-1H-benzo[f]
chromen-2-yl cyanide (4a)
2
2
2
NPs was vacuum-filtered, washed in ethanol, and dried
ꢀ
[40]
ꢀ
in a vacuum oven at 50 C for about 20 hours.
White powder; yield: 0.274 g (92%), m.p. 211-213 C (lit:
ꢀ
[26]
2
1
08-210 C
). IR (KBr): ν
= 3447, 3301, 3187, 2201,
max
−
1
1
657, 1600 cm .
H
NMR (300 MHz, DMSO-d6):
3
.3 | General procedure for preparation
δ = 4.93 (1 H, s, H-4), 6.46 (2 H, brs, NH ), 7.14 (1 H, d,
2
of compounds 4a-f and 6a-f
J = 8.3 Hz, HAr), 7.21-7.37 (5 H, m, HAr), 7.54-7.64 (3 H,
m, HAr), 7.89 (1 H, d, J = 8.3 Hz, HAr), 8.3 (1 H, d,
13
A mixture of aryl aldehyde (1 mmol), malononitrile
1.2 mmol), α-naphthol or β-naphthol (1 mmol), and
Ag Cr O NPs (64.8 mg, 15 mol%) in H O (3 mL) was
J = 8.3 Hz, HAr) ppm. C NMR (75 MHz, DMSO-d6):
δ = 58.75, 118.0, 119.33, 120.85, 123.38, 124.11, 126.33,
126.58, 126.70, 127.01, 127.70, 127.95, 128.67, 133.33,
143.27, 145.74, 160.04 ppm. Analysis calcd for C H N O
(
2
2
7
2
equipped with ultrasonic probe under the power of 60 W
at room temperature. After completion of the reaction, as
indicated by TLC (n-hexane/ethyl acetate 1:3), the reac-
tion mixture was cooled to ambient temperature, filtered,
and then poured into hot ethanol (2 mL), and the hetero-
geneous catalyst was removed by simple filtration,
washed with EtOH, and reused after dried in a vacuum
oven at 50 C for several hours. The ethanol solution was
cooled to room temperature, and the pure product was
grown from this solution.
20
14 2
(298.34): C 80.52, H 4.73, N 9.39; found C 80.63, H 4.89,
N 9.26.
3.3.2 | 3-Amino-1-(4-bromophenyl)-1H-
benzo[f]chromen-2-yl cyanide (4b)
ꢀ
ꢀ
White powder; yield: 0.358 g (95%), m.p. 237-239 C (lit:
ꢀ
[26]
240-242 C
). IR (KBr): νmax = 3417, 3326, 3071, 2195,

6
EBRAHIMI ET AL.
−1 1
1
625, 1593 cm . H NMR (300 MHz, DMSO-d ): δ = 4.97
ACKNOWLEDGEMENT
6
(
1 H, s, H-4), 6.51 (2 H, brs, NH ), 7.15 (1 H, d, J = 8.4 Hz,
Financial support from the Research Council of East
Tehran Branch, Islamic Azad University is gratefully
acknowledged.
2
HAr), 7.30 (2 H, d, J = 8.3 Hz, HAr), 7.53 (2 H, d, J = 8.3 Hz,
HAr), 7.58-7.65 (3 H, m, HAr), 7.90 (1 H, d, J = 8.5 Hz, HAr),
8
13
.30 (1 H, d, J = 7.9 Hz, HAr) ppm. C NMR (75 MHz,
DMSO-d ): δ = 58.2, 117.35, 119.13, 120.43, 120.87, 123.36,
ORCID
6
124.27, 126.15, 126.66, 126.83, 127.72, 130.08, 131.70, 133.42,
Shahrzad Abdolmohammadi https://orcid.org/0000-
1
43.31, 145.13, 160.07 ppm. Analysis calcd for C H BrN O
0001-8187-9624
20
13
2
(377.24): C 63.68, H 3.47, N 7.43; found C 63.86, H 3.61, N 7.53.
REFERENCES
[1] E. A. A. Hafez, M. H. Elnagdi, A. G. A. Elagamey, F. M.
A. A. El-Taweel, Heterocycles 1987, 26, 903.
3
.3.3 | 3-Amino-1-(3-chlorophenyl)-1H-
[
2] G. P. Ellis, Chromenes, chromanones, and chromones. in The
Chemistry of Heterocyclic Compounds Chromenes, A. Weissberger,
E. C. Taylor, Eds., chapter 2, pp. 11–139, John Wiley, USA,
New York, NY, 1997.
benzo[f]chromen-2-yl cyanide (4c)
ꢀ
White powder; yield: 0.313 g (94%), m.p. 219-220 C (lit:
ꢀ
−
[31]
2
18-222 C
). IR (KBr): νmax = 3455, 3340, 2192, 1659,
[3] A. Martínez-Grau, J. L. Marco, Bioorg Med Chem Lett 1997, 7,
1 1
1
590 cm . H NMR (300 MHz, DMSO-d ): δ = 5.00 (1 H,
6
3165.
s, H-4), 6.54 (2 H, brs, NH ), 7.17 (1 H, d, J = 8.3 Hz,
2
[4] M. M. Khafagy, A. H. F. A. El-Wahab, F. A. Eid, A. M. El-
Agrody, Farmaco 2002, 57, 715.
[5] A. H. Bedair, H. A. Emam, N. A. El-Hady, K. A. R. Ahmed,
A. M. El-Agrody, Farmaco 2001, 56, 965.
HAr), 7.30 (2 H, d, J = 8.3 Hz, HAr), 7.27-7.40 (4 H, m,
HAr), 7.56-7.65 (3 H, m, HAr), 7.90 (1 H, d, J = 8.5 Hz,
13
HAr), 8.31 (1 H, d, J = 7.8 Hz, HAr) ppm. C NMR
75 MHz, DMSO-d ): δ = 58.10, 117.21, 119.14, 120.90,
[6] S. J. Mohr, M. A. Chirigos, F. S. Fuhrman, J. W. Pryor, Cancer
Res 1975, 35, 3750.
(
6
1
1
1
7
23.37, 124.33, 126.10, 126.60, 126.69, 126.87, 127.15,
27.73, 127.87, 130.43, 133.45, 134.04, 143.36, 148.15,
[
7] C. P. Dell, C. W. Smith, Antiproliferative derivatives of 4H-
naphtho[1,2-b]pyran and process for their preparation,
European Patent Applications EP 537 949 21 Apr1. 993;
Chemical Abstracts 119, 139102d, 1993.
60.20 ppm. Analysis calcd for C H ClN O (332.79): C
20
13
2
2.18, H 3.94, N 8.42; found C 72.02, H 3.85, N 8.33.
[8] K. Hiramoto, A. Nasuhara, K. Michikoshi, T. Kato,
K. Kikugawa, Mutat Res 1997, 395, 47.
[
9] G. Bianchi, A. Tava, Agric Biol Chem 1987, 51, 2001.
3
.3.4 | 3-Amino-1-(4-cyanophenyl)-1H-
[
10] P. W. Smith, S. L. Sollis, P. D. Howes, P. C. Cherry,
I. D. Starkey, K. N. Cobley, H. Weston, J. Scicinski, A. Merritt,
A. Whittington, P. Wyatt, N. Taylor, D. Green, R. Bethell,
S. Madar, R. J. Fenton, P. J. Morley, T. Pateman, A. Beresford,
J Med Chem 1998, 41, 787.
[11] R. N. Taylor, A. Cleasby, O. Singh, T. Skarzynski, A. J. Wonacott,
P. W. Smith, S. L. Sollis, P. D. Howes, P. C. Cherry, R. Bethell,
P. Colman, J. Varghese, J Med Chem. 1998, 41, 798.
benzo[f]chromen-2-yl cyanide (6c)
ꢀ
White powder; yield: 0.285 g (88%), m.p. 255-257 C (lit:
ꢀ
[26]
258-260 C
). R (KBr): ν
= 3436, 3325, 3053, 2230,
max
−1
1
2190, 1655, 1630 cm . H NMR (300 MHz, DMSO-d ):
6
δ = 5.10 (1 H, s, H-4), 6.60 (2 H, brs, NH ), 7.15 (1 H, d,
J = 8.5 Hz, HAr), 7.56 (2 H, d, J = 8.3 Hz, HAr), 7.59-7.67
2
[
12] F. Eiden, F. Denk, Arch Pharm 1991, 324, 353, Synthese und
ZNS-Wirkung von Pyranderivaten: 6,8-Dioxabicyclo[3,2,1]
octane1), 354.
(3 H, m, HAr), 7.77 (2 H, d, J = 8.3 Hz, HAr), 7.90 (1 H, d,
1
3
J = 7.9 Hz, HAr), 8.31 (1 H, d, J = 7.8 Hz, HAr) ppm.
NMR (75 MHz, DMSO-d ): δ = 58.49, 111.75, 117.63,
C
6
[
13] A. T. Khan, L. H. Choudhury, S. Ghosh, Tetrahedron Lett
1
1
19.24, 119.91, 121.80, 124.26, 125.35, 126.88, 127.66, 127.88,
28.65, 129.94, 133.54, 134.42, 144.37, 151.81, 161.20 ppm.
2004, 45, 7891.
[
14] M. Gohain, D. Prajapati, J. S. Sandhu, Synlett 2004, 235.
Analysis calcd for C H N O (323.35): C 78.00, H 4.05, N
21
13
3
[15] S. Abdolmohammadi, S. Karimpour, Chin Chem Lett 2016,
27, 114.
12.99; found C 77.85, H 3.93, N 13.10.
[
[
[
[
[
16] S. Abdolmohammadi, R. Ghiasi, S. Ahmadzadeh-Vatani, Z
Naturforsch 2016, 71b, 777.
17] S. Abdolmohammadi, S. R. Rasouli Nasrabadi, A. Seif, N. Elmi
Fard, Comb Chem High T Scr 2018, 21, 323.
4
| CONCLUSIONS
18] N. Parikh, D. Kumar, S. R. Roy, A. K. Chakraborti, Chem
Commun 2011, 47, 1797.
19] G. Sharma, R. Kumar, A. K. Chakraborti, Tetrahedron Lett
A series of aminobenzochromenes were synthesized
using Ag Cr O NPs under ultrasonic irradiation in aque-
ous media at room temperature. The major advantages of
this green protocol are high yields of products, short reac-
tion times, easy and clean work-up, reusability, and high
efficiency of catalyst.
2
2 7
2008, 49, 4269.
20] A. K. Chakraborti, S. Rudrawar, K. B. Jadhav, G. Kaur,
S. V. Chankeshwara, Green Chem 2007, 9, 1335.
[21] S. V. Chankeshwara, A. K. Chakraborti, Org Lett 2006, 8, 3259.

EBRAHIMI ET AL.
7
[
[
[
[
22] Y. Q. Liu, L. H. Li, L. Yang, H. Y. Li, Chem Pap 2010, 64, 533.
23] M. Meciarova, V. Polackova, S. Toma, Chem Pap 2002, 56, 208.
24] M. Meciarova, S. Toma, P. Babiak, Chem Pap 2004, 58, 104.
25] K. Tabatabaeian, M. Mamaghani, N. O. Mahmoodi,
A. Khorshidi, Catal Commun 2008, 9, 416.
[35] M. Kidwai, S. Saxena, M. K. R. Khan, S. S. Thukral, Bioorg
Med Chem Lett 2005, 15, 4295.
[36] R. Maggi, R. Ballini, G. Sartori, R. Sartorio, Tetrahedron Lett
2004, 45, 2297.
[37] B. Sadeghi, I. Zarepour, J Nanostructure Chem 2015, 5, 305.
[38] A. F. Mahmoud, F. F. Abd El-Latif, A. M. Ahmed, Chin J
Chem 2010, 28, 91.
[
26] S. Taghavi Fardood, A. Ramazani, P. Azimzadeh Asiabi,
Y. Bigdeli Fard, B. Ebadzadeh, J. Asian, Green Chem 2017,
1
, 34.
[39] A. R. Moosavi-Zare, M. A. Zolfigol, O. Khaledian,
V. Khakyzadeh, M. H. Beyzavi, H. G. Kruger, Chem Eng J
2014, 248, 122.
[
[
27] B. Maleki, M. Baghayeri, S. Sheikh, S. Babaee, S. Farhadi, Russ
J Gen Chem 2017, 87, 1064.
28] J. Safari, M. Heydarian, Z. Zarnegar, Arab J Chem 2017, 10,
S2994.
[40] F. Soofivand, F. Mohandes, M. Salavati-Niasari, Micro Nano
Lett 2012, 7, 283.
[
[
29] B. Maleki, S. Sheikh, RSC Adv 2015, 5, 42997.
30] S. Abdolmohammadi, M. Afsharpour, S. Keshavarz-Fatideh, S
Afr J Chem-S Afr T 2014, 67, 203.
[
[
[
[
31] S. Balalaie, S. Ramezanpour, M. Bararjanian, J. H. Gross,
Synth Commun 2008, 38, 10789.
32] K. Gong, H. Wang, D. Fang, Z. Liu, Catal Commun 2008,
How to cite this article: Ebrahimi M,
Abdolmohammadi S, Kia-Kojoori R. Ultrasonic
accelerated efficient synthesis of
9, 650.
aminobenzochromenes using Ag Cr O
2 7
2
33] M. M. -Heravi, K. Bakhtiari, V. Zadsirjan, F. F. Bamoharram,
O. M.-Heravi, Bioorg Med Chem Lett 2007, 17, 4262.
34] B. S. Kumar, N. Srinivasulu, R. H. Udupi, B. Rajitha,
Y. T. Reddy, P. N. Reddy, P. S. Kumar, J Heterocycl Chem
nanoparticles as a reusable heterogeneous catalyst.
J Heterocyclic Chem. 2020;1–7. https://doi.org/10.
1002/jhet.3915
2
006, 43, 1691.