Nanomagnetically modified thioglycolic acid (γ-Fe2O3@SiO2-SCH2CO2H): Efficient and reusable green catalyst for the one-pot domino synthesis of spiro[benzo[a]benzo[6,7]chromeno[2,3-c]phenazine] and benzo[a]benzo[6,7]chromeno[2,3-c]phenazines

Article abstract of DOI:10.1002/aoc.3791

Superparamagnetic nanoparticles of modified thioglycolic acid (γ-Fe₂O₃@SiO₂-SCH₂CO₂H) represent a new, efficient and green catalyst for the one-pot synthesis of novel spiro[benzo[a]benzo[6,7]chromeno[2,3-c]phenazine] derivatives via domino Knoevenagel–Michael–cyclization reaction of 2-hydroxynaphthalene-1,4-dione, benzene-1,2-diamines, ninhydrin and isatin. This novel magnetic organocatalyst was easily isolated from the reaction mixture by magnetic decantation using an external magnet and reused at least six times without significant loss in its activity. The catalyst was fully characterized using various techniques. This procedure was also applied successfully for the synthesis of benzo[a]benzo[6,7]chromeno[2,3-c]phenazines.

Full text of DOI:10.1002/aoc.3791

Received: 9 January 2017
DOI: 10.1002/aoc.3791
Revised: 6 February 2017
Accepted: 12 February 2017
F U L L PA P E R
Nanomagnetically modified thioglycolic acid (γ‐Fe O @SiO ‐
2
3
2
SCH CO H): Efficient and reusable green catalyst for the one‐pot
2
2
domino synthesis of spiro[benzo[a]benzo[6,7]chromeno[2,3‐c]
phenazine] and benzo[a]benzo[6,7]chromeno[2,3‐c]phenazines
1
2
3
Sajjad Abbasi Pour | Afshin Yazdani‐Elah‐Abadi
| Mojgan Afradi
1
Department of Chemistry, Faculty of
Superparamagnetic nanoparticles of modified thioglycolic acid (γ‐Fe O @SiO ‐
Science, University of Sistan and
Baluchestan, Zahedan, Iran
2
3
2
SCH CO H) represent a new, efficient and green catalyst for the one‐pot synthesis
2
2
2
Department of Biology, Science and Art
of novel spiro[benzo[a]benzo[6,7]chromeno[2,3‐c]phenazine] derivatives via
domino Knoevenagel–Michael–cyclization reaction of 2‐hydroxynaphthalene‐1,4‐
dione, benzene‐1,2‐diamines, ninhydrin and isatin. This novel magnetic
organocatalyst was easily isolated from the reaction mixture by magnetic decanta-
tion using an external magnet and reused at least six times without significant loss
in its activity. The catalyst was fully characterized using various techniques. This
procedure was also applied successfully for the synthesis of benzo[a]benzo[6,7]
chromeno[2,3‐c]phenazines.
University, Yazd, Iran
3
Department of Chemistry, Niksaman Daruo
Pharmaceutical Company, Tehran, Iran
Correspondence
Afshin Yazdani‐Elah‐Abadi, Department of
Biology, Science and Art University, Yazd,
Iran.
Email: afi_yazdani@yahoo.com
KEYWORDS
encapsulated iron oxide nanoparticles, green chemistry, magnetically recoverable nanocatalyst, modified
thioglycolic acid, multi‐component domino reactions (MDRs), spiro[benzo[a]benzo[6,7]chromeno[2,3‐c]
phenazine]
1
| INTRODUCTION
Therefore, the design of novel MDRs for the synthesis of
diverse heterocycles has remained an important topic for
Diversity‐oriented synthesis (DOS) has played a critical role at
medicinal and organic chemistry. Heterocycles having phen-
azine, quinoxaline and chromene moieties are important tar-
the interface of the fields of organic synthesis and chemical
[
1–3]
[10–14]
biology.
At the heart of DOS are the synthetic means
gets in synthetic organic chemistry. While phenazines,
[
15–18]
[19–23]
needed for the generation of collections of functionally and
regiochemically diverse small molecules, particularly those
possessing skeletons resembling those found in natural prod-
quinoxalines
and chromenes
have attracted great
attention in medicinal chemistry and drug discovery, the
preparation of compounds incorporating all of these motifs
(Figure 1) has not been reported.
[4]
ucts or drug‐like molecules. Multi‐component domino reac-
tions (MDRs), in which more than two components are
combinedinasinglesyntheticoperation, haveplayedanimpor-
tant role in this area due to their atom efficiency, operational
simplicity, high selectivity, usually excellent productivity, fac-
ile execution, lowcosts, minimum waste production, structural
diversity, shorter reaction times, environmental friendliness
Moreover, spiro heterocycles are found in a number of
[
24,25]
natural and synthetic molecules.
A spiro heterocyclic
compound in which the spiro carbon is part of the cyclic ring
[
26–29]
has many unique properties,
and they are particularly
interesting because the conformational restriction associated
with the structural rigidity affects considerably their biologi-
[5–9]
[30]
and allowing savings of both solvents and reagents.
cal activity.
Appl Organometal Chem. 2017;e3791.
wileyonlinelibrary.com/journal/aoc
Copyright © 2017 John Wiley & Sons, Ltd.
1 of 13
https://doi.org/10.1002/aoc.3791

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ABBASI POUR ET AL.
2
| RESULTS AND DISCUSSION
In this work, we report thioglycolic acid‐coated MNPs as a
new catalyst for the synthesis of novel spiro[benzo[a]benzo
[6,7]chromeno[2,3‐c]phenazine] and benzo[a]benzo[6,7]
chromeno[2,3‐c]phenazine derivatives. Initially,
superparamagnetic Fe O4 nanoparticles were synthesized
3
using the chemical co‐precipitation method from ferric and
FIGURE 1 Structure of designed compound
ferrous ions in ammonia solution with minor modifica-
[
44]
Nanomaterial applications as heterogeneous catalysts
have expanded in organic synthesis due to high surface area,
surface modification ability, excellent thermal and chemical
stability, simple work‐up procedures, environmentally benign
nature, reusability, low cost and ease of synthesis and isola-
tions.
In the next step, the nanoparticles were converted
to γ‐Fe O at 300 °C for 3 h. Subsequently, γ‐Fe O was
encapsulated by tetraethyl orthosilicate (TEOS; Si(OEt) ) as
2
3
2 3
4
[
45]
Fe O @SiO .
Then, chlorofunctionalized γ‐Fe O @SiO
2
3
2
2
3
2
[
46]
was synthesized.
acid with chlorofunctionalized γ‐Fe O @SiO formed new
superparamagnetic
Eventually, the reaction of thioglycolic
[
31–35]
tion.
non‐toxic magnetic nanoparticles (MNPs) such as magnetite
Fe O ) and maghemite (γ‐Fe O ) are often considered to
Among them, organic processes catalysed by
2
3
2
silica‐encapsulated
γ‐Fe O3
(γ‐
2
(
Fe O @SiO @thioglycolic acid) as the catalyst (Figure 2).
2 3 2
3
4
2
3
follow the principles of green chemistry, i.e. those catalysed
processes that consume a minimum of energy and reagents
or auxiliaries and minimize waste.
MNPs‐thioglycolic acid was characterized with various
techniques and its potential as a catalyst was studied. The
structure of the magnetic nanocatalyst was characterized
using various techniques such as Fourier transform infrared
(FT‐IR) spectroscopy, X‐ray diffraction (XRD), scanning
electron microscopy (SEM), vibrating sample magnetometry
(VSM), energy‐dispersive X‐ray spectroscopy (EDS) and
thermogravimetric analysis (TGA).
[36,37]
Considering the importance of phenazine, quinoxaline and
chromene derivatives and in continuation of our research on
multi‐component reactions and our ongoing programme for
the synthesis of complex organic compounds based on green
[
38–43]
chemistry protocols,
herein we report a green synthesis
of functionalized spiro[benzo[a]benzo[6,7]chromeno[2,3‐c]
phenazine] and benzo[a]benzo[6,7]chromeno[2,3‐c]phena-
zine derivatives catalysed by superparamagnetic nanoparticles
of modified thioglycolic acid as a new and efficient catalyst in
The FT‐IR spectrum of γ‐Fe O @SiO @thioglycolic
2
3
2
acid is shown in Figure 3. The Fe─O stretching vibration
−
1
near 580 cm , the O─H stretching vibration at 3300–
−1
−1
3500 cm , the Si─O stretching at 1000–1110 cm , the
C═O vibration at 1600–1750 cm− and the C─H stretching
1
EtOH–H O (1:1) at 70 °C (Scheme 1).
2
SCHEME 1 One‐pot, domino, multi‐
component synthesis of novel spiro[benzo[a]
benzo[6,7]chromeno[2,3‐c]phenazine] and
benzo[a]benzo[6,7]chromeno[2,3‐c]
phenazine derivatives in the presence of
2
γ‐Fe O
3
@SiO
2 2 2
‐SCH CO H

ABBASI POUR ET AL.
3 of 13
FIGURE 2 Synthesis of MNPs‐
thioglycolic acid as new heterogeneous
catalyst
((220), (311), (400), (422), (511) and (440)) were identified
in XRD pattern, demonstrating the structure of MNPs. The
XRD pattern of γ‐Fe O @SiO @thioglycolic acid showed
2
3
2
that thioglycolic acid and SiO formed amorphous phase,
2
with the pattern showing only crystalline γ‐Fe O nanoparti-
2
3
cles (JCPDS card no. 39‐1346).
The crystalline size and morphology of the prepared cat-
alyst were characterized using SEM. The SEM images of
MNPs‐thioglycolic acid show spherical morphology and the
average size of the nanoparticles is 15.6 nm from the histo-
gram of particle size distribution (Figure 5).
2 3 2
FIGURE 3 FT‐IR spectrum of γ‐Fe O @SiO @thioglycolic acid
The VSM curves show the magnetic properties of
γ‐Fe O and MNPs‐thioglycolic acid and also prove that
2
3
these nanoparticles are superparamagnetic (Figure 6). Satura-
vibration at 2948 cm− were observed. This spectrum proved
that thioglycolic acid was successfully attached on the surface
of γ‐Fe O @SiO nanoparticles.
1
tion magnetization of MNPs was 63.8 emu g− and saturation
1
−
1
magnetization of MNPs‐thioglycolic acid was 50.9 emu g .
The saturation magnetization of MNPs‐thioglycolic acid was
2
3
2
Figure 4 shows the XRD pattern of crystalline structure
of γ‐Fe O @SiO @thioglycolic acid. Six diffraction peaks
obviously decreased as compare with the uncoated γ‐Fe O3
2
2
3
2
nanoparticles. This decrease in magnetization of MNPs‐
thioglycolic acid is because of the presence of organic mate-
rial and SiO in the surface of MNPs‐thioglycolic acid.
2
The components of γ‐Fe O @SiO @thioglycolic acid
2
3
2
were analysed using EDS (Figure 7). The EDS spectrum
obviously indicates the presence of Fe, O, Si, C and S atoms
in the catalyst.
The thermal stability of MNPs‐thioglycolic acid was
investigated using TGA (Figure 8). The small weight loss
occurring below 100 °C is due to solvent desorption. The
second weight loss can be attributed to the decomposition
of the organic part. As can be seen from the TGA curve,
the amount of organic compound was about 6.5% versus
the total heterogeneous catalyst. Considering this weight loss,
it was calculated that 0.71 mmol of thioglycolic acid was
loaded on 1 g of MNPs‐thioglycolic acid catalyst.
2 3 2
FIGURE 4 XRD pattern of γ‐Fe O @SiO @thioglycolic acid

4
of 13
ABBASI POUR ET AL.
2 3 2
FIGURE 5 SEM images and histogram of particle size distribution of γ‐Fe O @SiO @thioglycolic acid
This newly synthesized catalyst consists of economically
cost‐effective and modified non‐toxic MNPs, and its struc-
ture convinced us that it could be used as an efficient, green
and solid acid catalyst in the synthesis of novel spiro[benzo
In order to investigate the optimal reaction conditions for
the synthesis of functionalized spiro[benzo[a]benzo[6,7]
chromeno[2,3‐c]phenazine] derivatives, we carried out the
MDR reaction of 2‐hydroxynaphthalene‐1,4‐dione (1;
1 mmol), 2a (1 mmol) and isatin (4; 1 mmol) in ethanol as
a model (Scheme 3). Initially, to minimize the formation of
by‐products, 1 and 2a were refluxed in ethanol until in less
than 10 min an orange solid of benzo[a]phenazine (3a) was
formed without using any catalyst. Next, 4 and 1 were added
and the mixture was heated in EtOH under reflux conditions.
The desired product 8 was not obtained when the reaction
was carried out in EtOH for 4 h under reflux and catalyst‐free
conditions (Table 1, entry 1). However, 8a was obtained in
83% yield when the reaction was conducted in the presence
of thioglycolic acid (0.005 g) in EtOH (Table 1, entry 2).
[
a]benzo[6,7]chromeno[2,3‐c]phenazine] and benzo[a]
benzo[6,7]chromeno[2,3‐c]phenazine derivatives. For this
purpose, at first, the aromatic ketones 6a–d were synthesized
[47]
according to previous work, by means of reaction between
ninhydrin (2,2‐dihydroxyindane‐1,3‐dione; 5) and various
aromatic 1,2‐diamines, namely benzene‐1,2‐diamine (2a),
4‐methylbenzene‐1,2‐diamine (2b), 4‐nitrobenzene‐1,2‐
diamine (2c) and 2,3‐diaminopyridine (2d) (Scheme 2). In
the cases of 2a and 2b, higher yields of the products were
obtained in shorter reaction times in comparison with 2c
and 2d.

ABBASI POUR ET AL.
5 of 13
Higher yields were obtained in shorter reaction times
when the reaction was carried out in EtOH–H O (1:1), due
2
to its strong hydrogen bonding ability, hydrophobic effects
and high polarity. In this experiment any other organic sol-
vents were not tested because of the green chemistry concept.
After extensive screening, we found that the best yields and
time profiles were obtained when the reaction was carried
out in the presence of 0.03 g of γ‐Fe O @SiO ‐SCH CO H
2
3
2
2
2
in EtOH–H O (1:1) at 70 °C, which afforded the
2
corresponding
spiro[benzo[a]benzo[6,7]chromeno[2,3‐c]
phenazine‐17,3′‐indoline]‐2′,11,16‐trione (8a) in 2 h with
9
2% yield (Table 1, entry 10).
To generate a small library of functionalized spiro[benzo
[
a]benzo[6,7]chromeno[2,3‐c]phenazine] derivatives 8, we
next utilized a variety of substrates to explore the synthetic
scope and generality of this accelerated one‐pot Knoevenagel
condensation–Michael addition–cyclization cascade reaction
under optimal conditions. Representative results are summa-
rized in Table 2.
FIGURE VSM
6
curves
of
γ‐Fe
2
O
3
and
γ‐
Fe @SiO @thioglycolic acid
2
O
3
2
The structures of these new compounds were deduced
1
from their satisfactory elemental and spectral (FT‐IR, H
13
Different catalysts were evaluated in the model reaction,
NMR, C NMR) analyses. The mass spectra of these
compounds displayed molecular ion peaks at the appropriate
m/z values.
including nano‐SiO , SiO ‐SO H, γ‐Fe O , γ‐Fe O @SiO
2
2
3
2
3
2
3
2
and γ‐Fe O @SiO ‐SCH CO H; these were all added in
2
3
2
2
2
sub‐stoichiometric amount (0.03 g) and the reactions were
carried out in EtOH under reflux conditions. Eventually, we
found that γ‐Fe O @SiO ‐SCH CO H (0.03 g) showed
excellent catalytic activity in terms of reaction time as well
as yield of product. Also, to select the best solvent for the
reaction, the synthesis of compound 8a was examined in var-
ious solvents (Table 1). The examined solvents were not effi-
cient separately.
Then, using these optimized reaction conditions, the
scope and efficiency of the reaction were explored for the
synthesis of benzo[a]benzo[6,7]chromeno[2,3‐c]phenazine
derivatives 9. An extensive range of substituted and structur-
ally diverse aldehydes (ortho‐, meta‐ and para‐substituted)
afforded the corresponding products in high to excellent
yields using MNPs‐thioglycolic acid as an environmentally
friendly catalyst. As is evident from Table 3, the reactions
2
3
2
2
2
2 3 2
FIGURE 7 EDS spectrum of γ‐Fe O @SiO @thioglycolic acid

6
of 13
ABBASI POUR ET AL.
2 3 2
FIGURE 8 TGA and differential TGA of γ‐Fe O @SiO @thioglycolic acid
groups on the benzene ring. Also, in the presence of ali-
phatic aldehydes such as n‐heptanal and n‐octanal, the
expected product was not obtained under these reaction
conditions.
The recovery and reuse of catalysts are important advan-
tages in green chemistry and heterogeneous catalysis; and
also important from an industrial point of view in large‐scale
operations and commercial applications. In this regard, we
also investigated the recyclability of MNPs‐thioglycolic acid
SCHEME
2
Synthesis of 11H‐indeno[1,2‐b]quinoxalin‐11‐one
derivatives and 6H‐indeno[1,2‐b]pyrido[3,2‐e]pyrazin‐6‐one
in EtOH–H O (1:1) at 70 °C using a selected model reaction
2
of 1, 2 and isatin in the presence of MNPs‐thioglycolic acid
(Table 2, entry 1). After completion of the reaction, the reac-
were efficiently promoted using arylaldehydes with elec-
tron‐withdrawing groups with increased yields and reduced
reaction times rather than substitutions of electron‐donating
tion mixture was diluted with hot ethanol and the catalyst was
easily separated from the reaction mixture using an external
magnetic field, washed with hot ethanol, dried in air and
SCHEME 3 Synthesis of novel spiro[benzo[a]benzo[6,7]chromeno[2,3‐c]phenazine] derivatives

ABBASI POUR ET AL.
7 of 13
TABLE 1 Optimization of reaction conditions for compound 8a
a
Entry
Catalyst (g)
Reaction conditions
Time (h)
Yield (%)
1
2
3
4
5
6
7
8
9
—
EtOH, reflux
EtOH, reflux
EtOH, reflux
EtOH, reflux
EtOH, reflux
EtOH, reflux
EtOH, reflux
4
2
2
2
2
2
2
2
2
2
3
6
2
2
Nil
83
Thioglycolic acid (0.005)
SiO
2
‐SO
3
H (0.03)
(0.03)
(0.03)
78
Nano‐SiO
2
42
γ‐Fe
γ‐Fe
γ‐Fe
γ‐Fe
γ‐Fe
γ‐Fe
γ‐Fe
γ‐Fe
γ‐Fe
γ‐Fe
2
O
2
O
2
O
2
O
2
O
2
O
2
O
2
O
2
O
2
O
3
3
3
3
3
3
3
3
3
3
64
@SiO
@SiO
@SiO
@SiO
@SiO
@SiO
@SiO
@SiO
@SiO
2
(0.03)
71
2
2
2
2
2
2
2
2
‐SCH
‐SCH
‐SCH
‐SCH
‐SCH
‐SCH
‐SCH
‐SCH
2
2
2
2
2
2
2
2
CO
CO
CO
CO
CO
CO
CO
CO
2
2
2
2
2
2
2
2
H (0.03)
H (0.03)
H (0.03)
H (0.03)
H (0.03)
H (0.03)
H (0.06)
H (0.015)
87
H
2
O, reflux
80
EtOH–H
EtOH–H
EtOH–H
EtOH–H
EtOH–H
EtOH–H
2
2
2
2
2
2
O (1:1), reflux
O (1:1), 70 °C
O (1:1), 50 °C
O (1:1), r.t.
91
1
1
1
1
1
0
1
2
3
4
92
88
Trace
92
O (1:1), 70 °C
O (1:1), 70 °C
86
a
Isolated yield.
TABLE 2 One‐pot multi‐component domino synthesis of spiro[benzo[a]benzo[6,7]chromeno[2,3‐c]phenazine] derivatives using MNPs‐
thioglycolic acid (0.03 g) as catalyst in EtOH–H O (1:1) at 70 °C
2
a
Entry
Cyclic ketone
Product
Time (h)
Yield (%)
1
2
3
4
5
6
4
8a
8b
8c
8d
8e
8f
2
2
3
3
3
3
92
88
87
85
81
79
5
6a
6b
6c
6d
a
Isolated yield.
reused for a subsequent similar reaction. The recovered cata-
lyst was reused for six consecutive cycles without any signif-
icant loss in its catalytic activity (Figure 9).
In order to determine the catalytic behaviour of
MNPs‐thioglycolic acid, a suggested mechanism for the
formation of products is shown in Scheme 4. On the basis

8
of 13
ABBASI POUR ET AL.
TABLE 3 One‐pot multi‐component domino synthesis of benzo[a]benzo[6,7]chromeno[2,3‐c]phenazine derivatives using MNPs‐thioglycolic acid
2
(0.03 g) as catalyst in EtOH–H O (1:1) at 70 °C
a
Entry
Aldehyde
Product
Time (h)
Yield (%)
M.p. (obs.) (°C)
M.p. (lit.) (°C)
[
[
[
[
[
[
[
[
[
42]
42]
42]
42]
42]
42]
42]
42]
42]
1
2
3
4
5
6
7
8
9
4‐ClC
6
H
H
4
4
9a
9b
9c
9d
9e
9f
2
2
2
2
2
2
2
3
3
3
3
3
3
4
4
94
92
92
93
91
90
88
89
86
85
83
89
85
NR
NR
325–327
334–336
331–332
273
324–326
336–338
330–332
273–275
368–370
293–295
289–291
333–335
341–342
2‐ClC
6
2 6 3
2,4‐Cl C H
4‐NO
3‐NO
2‐NO
2 6 4
C H
2
C
C
6
6
H
4
4
370–372
294–296
286–288
333–335
342–344
320–321
301–303
365
2
H
3‐CNC
6
H
3
9g
9h
9i
4‐CH
3
3
C
6
H
4
4‐CH
OC
6
H
4
10
11
12
13
14
15
3,4‐(CH
4‐OHC
2‐OH‐5‐NO
3
O)
2
C
6
H
3
9j
Present work
6
H
4
9k
9l
Present work
[
[
42]
42]
2
C
6
H
3
364–366
359–361
—
5‐Br‐2‐OHC
n‐Heptanal
n‐Octanal
6
H
3
9m
—
—
356–358
—
—
—
a
Isolated yield.
FIGURE 9 Reusability of nanocatalyst
of this mechanism, at first, 1 tautomerizes to intermediate
‐hydroxy‐1,2‐naphthoquinone (10). The primary conden-
sation of 10 with 2 produces 6H‐benzo[a]phenazin‐5‐ol
3). With this mechanism, MNPs‐thioglycolic acid is an
efficient catalyst for forming the olefin 11, which is read-
ily prepared in situ from Knoevenagel condensation of
carbonyl groups of aldehyde or cyclic ketone 4–6 with
1. The Michael addition of 3 with olefin 11 in the
presence of MNPs‐thioglycolic acid finally gives interme-
diate 12, which then makes the inner molecular ring to
be formed after a tautomeric proton shift to produce
4
(
spiro[benzo[a]benzo[6,7]chromeno[2,3‐c]phenazine]
and
benzo[a]benzo[6,7]chromeno[2,3‐c]phenazine derivatives 8
and 9.

ABBASI POUR ET AL.
9 of 13
SCHEME 4 Proposed mechanism for the
synthesis of novel spiro[benzo[a]benzo[6,7]
chromeno[2,3‐c]phenazine] and benzo[a]
benzo[6,7]chromeno[2,3‐c]phenazine
derivatives
3
| CONCLUSIONS
as potential drug candidates, since phenazine, quinoxaline
and chromene motifs have a vast range of biological
activities.
In summary, we synthesized superparamagnetic nanoparti-
cles of modified thioglycolic acid (γ‐Fe O @SiO ‐
2
3
2
SCH CO H) as a novel, efficient and reusable catalyst and
2
2
4
4
| EXPERIMENTAL
.1 | General
characterized the catalyst using TGA, FT‐IR spectroscopy,
SEM, XRD, EDS and VSM. This newly synthesized catalyst
was applied as a green heterogeneous organic acid for the
efficient synthesis of novel spiro[benzo[a]benzo[6,7]
All melting points were determined with an Electrothermal
9100 apparatus and are uncorrected. FT‐IR spectra were
recorded with a Shimadzu IR‐470 spectrometer. Elemental
analyses for C, H and N were performed using a Heraeus
CHN‐O‐Rapid analyser at Iranian Central Research of Petro-
leum Company. Mass spectra were recorded with an Agilent
Technology (HP) spectrometer operating at an ionization
potential of 70 eV. H NMR and C NMR spectra were
recorded with Bruker DRX‐400 Avance instruments with
deuterated dimethylsulfoxide (DMSO‐d ) as solvent. TLC
chromeno[2,3‐c]phenazine]
and
benzo[a]benzo[6,7]
chromeno[2,3‐c]phenazine derivatives through single‐pot
domino Knoevenagel–Michael–annulation reaction. The
environmentally friendly methodology with excellent green
chemistry credentials, such as using low loading of reusable,
non‐toxic, easy‐to‐handle catalyst, shorter reaction time with-
out any by‐product, avoidance of hazardous organic solvents
and easy work‐up (the catalyst can be easily separated from
the reaction mixture using an external magnet), may find a
wide range of applications. Furthermore, this attractive
atom‐economical protocol is expected to produce compounds
exhibiting interesting pharmacological activities and may act
1
13
6
was performed on silica gel Polygram SILG/UV 254 plates.
Elemental compositions were determined with a Leo 1450
VP scanning electron microscope equipped with an SC7620

1
0 of 13
ABBASI POUR ET AL.
energy dispersive spectrometer presenting a 133 eV resolu-
tion at 20 kV. Powder XRD was performed using a Bruker
D8‐advance X‐ray diffractometer with Cu Kα
4.6 | General procedure for synthesis of novel
spiro[benzo[a]benzo[6,7]chromeno[2,3‐c]
phenazine] and benzo[a]benzo[6,7]chromeno
[2,3‐c]phenazine derivatives (8, 9)
(
λ = 0.154 nm) radiation. All reagents and solvents were pur-
chased from Merck and Aldrich and used without further
purification.
Compounds 1 (1 mmol) and 2a (1 mmol), MNPs‐thioglycolic
acid (0.03 g) and 30 ml of EtOH–H O (1:1 v/v) were placed
2
in a 50 ml round‐bottomed flask mounted over a magnetic
stirrer. The contents were stirred magnetically in an oil bath
maintained at 70 °C until in less than 10 min compound 3
was formed. Then, 1 (1 mmol) and cyclic ketones 4/5/6 or
aryl aldehyde 7 (1 mmol) were added to the reaction mixture
which was heated further for the times reported in Tables 2
and 3. Upon completion of the reaction, monitored by TLC,
the reaction mixture was diluted with hot ethanol and the cat-
alyst was easily separated from the reaction mixture using an
external magnet, washed with hot ethanol, dried and reused
for a consecutive run under the same reaction conditions.
Then, the reaction mixture was cooled to room temperature
and the crude product obtained was collected by filtration
and recrystallized from hot ethanol to afford the pure solids
4
.2 | Synthesis of γ‐Fe O3
2
FeCl ⋅4H O (0.802 g) and FeCl ⋅6H O (2.184 g) were dis-
solved in water (10 ml) separately under argon atmosphere
at 25 °C. NH ⋅H O solution (0.7 M, 100 ml) was added
dropwise in 5–10 min to the stirring mixture at 25 °C to
adjust the reaction pH to 11. MNPs were collected using a
powerful external magnet, decanted and, to remove all ions,
washed three times with deionized water. Subsequently,
tetramethylammonium hydroxide (1–2 ml) was added
dropwise to the nanomaterials, stirred rapidly and then the
precipitate collected. The dried precipitate of Fe O was kept
2
2
3
2
3
2
3
4
in a furnace for 3 h at 300 °C to afford a reddish‐brown pow-
der of γ‐Fe O nanoparticles.
[44,45]
2
3
8
and 9.
4
.3 | Synthesis of γ‐Fe O @SiO
2
3
2
4
.7 | Analytical and spectroscopic data for
A mixture of γ‐Fe O (2 g) in ethanol (40 ml) was sonicated
for 30 min and then heated for 1 h at 40 °C. Then, TEOS
2
3
unknown compounds
(
10 ml) was added to the reaction mixture, and continuously
4
.7.1 | Spiro[benzo[a]benzo[6,7]chromeno
stirred for 24 h. The silica‐coated nanoparticles were sepa-
rated using an external magnet, washed three times with
EtOH and diethyl ether and then dried in vacuum at 100 °C
[2,3‐c]phenazine‐17,3′‐indoline]‐2′,11,16‐trione
(8a)
[
45]
Orange solid; yield 92%, 0.489 g; m.p. 297–299 °C. FT‐IR
for 12 h.
−
1
(KBr, νmax, cm ): 3305, 2925, 1692, 1614, 1589, 1530,
1
1
497, 1412, 1332, 1247, 1153, 1073, 767. H NMR
4
.4 | Synthesis of chloro‐functionalized γ‐
(400 MHz, DMSO‐d , δ, ppm): 6.64 (t, 1H, J = 6.8 Hz,
Ar‐H), 7.05 (t, 2H, J = 7.2 Hz, Ar‐H), 7.13 (t, 1H,
J = 7.6 Hz, Ar‐H), 7.79 (t, 1H, J = 7.6 Hz, Ar‐H), 7.93–
6
Fe O @SiO
2
3
2
An amount of 2 g of γ‐Fe O @SiO in 40 ml of dry toluene
was sonicated for 45 min. Then
chloropropyltrimethoxysilane was added to the dispersed
γ‐Fe O @SiO in toluene and heated and stirred at 100 °C
for 24 h. MNPs were collected using a strong external mag-
net, washed with EtOH and diethyl ether three times, then
dried at 40 °C in an oven for 12 h.
2
3
2
8
.11 (m, 7H, Ar‐H), 8.28–8.30 (m, 1H, Ar‐H), 8.60 (d, 1H,
1
ml of 3‐
J = 7.6 Hz, Ar‐H), 8.85 (d, 1H, J = 7.6 Hz, Ar‐H), 9.29 (d,
13
1
H, J = 8.0 Hz, Ar‐H), 11.55 (s, 1H, NH). C NMR
2
3
2
(
100 MHz, DMSO‐d , δ, ppm): 50.5, 108.5, 112.5, 115.8,
6
1
20.8, 121.4, 123.0, 125.3, 125.5, 128.0, 128.3, 128.5,
[46]
128.9, 129.9, 130.2, 130.8, 131.1, 132.0, 135.4, 140.3,
1
1
41.0, 143.6, 144.9, 146.7, 151.8, 153.4, 155.8, 169.5,
76.5, 177.8. MS (m/z, %): 531 (M , 5). Anal. Calcd for
+
4
.5 | Synthesis of γ‐Fe O @SiO @thioglycolic
C H N O (%): C, 76.83; H, 3.22; N, 7.91. Found (%): C,
34 17 3 4
2
3
2
acid
7
6.98; H, 3.36; N, 8.12.
A suspension of γ‐Fe O @SiO (1 g) in ethanol (15 ml) in a
2
3
2
5
0 ml round‐bottom flask was sonicated for 30 min, and sub-
4
.7.2 | Spiro[benzo[a]benzo[6,7]chromeno
sequently thioglycolic acid (1 ml) was added dropwise. Then,
the reaction mixture was stirred at 25 °C overnight. Finally,
precipitates were collected using an external magnet, washed
three times with EtOH and diethyl ether and then dried for
[
2,3‐c]phenazine‐17,2′‐indene]‐1′,3′,11,16‐
tetraone (8b)
Orange solid; yield 88%, 0.479 g; m.p. 210 °C. FT‐IR (KBr,
νmax, cm ): 3025, 1706, 1660, 1629, 1610, 1590, 1536,
−
1
12 h at 40 °C in an oven (Figure 2).

ABBASI POUR ET AL.
11 of 13
1
1
467, 1315, 1286, 1178, 1079, 758. H NMR (400 MHz,
Calcd for C H N O (%): C, 79.99; H, 3.52; N, 8.88.
4
2 22 4 3
DMSO‐d , δ, ppm): 7.64 (t, 1H, J = 7.2 Hz, Ar‐H), 7.74
Found (%): C, 79.81; H, 3.74; N, 8.79.
6
(
d, 1H, J = 7.2 Hz, Ar‐H), 7.90–7.99 (m, 6H, Ar‐H), 8.11–
.16 (m, 3H, Ar‐H), 8.24–8.28 (m, 2H, Ar‐H), 8.63 (d, 1H,
J = 8.0 Hz, Ar‐H), 8.82 (d, 1H, J = 7.6 Hz, Ar‐H), 9.20
8
4
.7.5 | 7′‐Nitrospiro[benzo[a]benzo[6,7]
chromeno[2,3‐c]phenazine‐17,11′‐indeno[1,2‐b]
quinoxaline]‐11,16‐dione (8e)
1
3
(d, 1H, J = 6.0 Hz, Ar‐H).
C NMR (100 MHz,
DMSO‐d , δ, ppm): 67.5, 112.6, 116.2, 122.6, 122.9,
6
1
1
1
1
25.0, 125.4, 128.6, 129.2, 129.3, 129.9, 130.5, 130.6,
31.3, 131.8, 133.6, 134.6, 136.2, 139.1, 139.7, 141.7,
42.0, 145.7, 147.0, 152.2, 154.0, 156.5, 175.8, 177.8,
Brown solid; yield 81%, 0.535 g; m.p. 220–223 °C. FT‐IR
−
1
(KBr, νmax, cm ): 2900, 1715, 1657, 1582, 1530, 1503,
1
1331, 1263, 1188, 1062, 758. H NMR (400 MHz, DMSO‐
+
98.2. MS (m/z, %): 544 (M , 11). Anal. Calcd for
d6, δ, ppm): 7.67–7.69 (m, 2H, Ar‐H), 7.74–7.80 (m, 5H,
Ar‐H), 7.86–7.90 (m, 3H, Ar‐H), 7.92–7.95 (m, 1H, Ar‐H),
8.00–8.09 (m, 3H, Ar‐H), 8.25 (d, 1H, J = 8.8 Hz, Ar‐H),
C H N O (%): C, 77.20; H, 2.96; N, 5.14. Found (%): C,
7
3
5 16 2 5
7.44; H, 3.08; N, 5.03.
8
.44 (d, 1H, J = 7.6 Hz, Ar‐H), 8.52 (dd, 1H, J = 9.2 Hz,
1
J = 2.4 Hz, Ar‐H), 8.87 (d, 1H, J = 2.4 Hz, Ar‐H), 9.39
2
4
.7.3 | Spiro[benzo[a]benzo[6,7]chromeno
13
(
d, 1H, J = 8.0 Hz, Ar‐H). C NMR (100 MHz, DMSO‐
d6, δ, ppm): 44.7, 110.2, 112.1, 119.4, 120.2, 120.7, 122.9,
24.3, 125.3, 126.2, 126.9, 128.7, 129.3, 130.5, 130.7,
[
2,3‐c]phenazine‐17,11′‐indeno[1,2‐b]
quinoxaline]‐11,16‐dione (8c)
1
Brown solid; yield 87%, 0.536 g; m.p. 163–165 °C. FT‐IR
131.2, 131.8, 132.2, 132.7, 133.2, 133.7, 133.9, 136.0,
137.1, 138.9, 139.9, 140.2, 140.7, 141.5, 143.1, 147.7,
152.0, 156.0, 157.0, 177.6, 178.2. MS (m/z, %): 661 (M ,
−
1
(
KBr, νmax, cm ): 3035, 1716, 1660, 1587, 1537, 1448,
1
+
1327, 1262, 1192, 1038, 757. H NMR (400 MHz, DMSO‐
d6, δ, ppm): 7.50 (d, 1H, J = 7.6 Hz, Ar‐H), 7.70 (t, 2H,
J = 7.6 Hz, Ar‐H), 7.82–7.93 (m, 7H, Ar‐H), 8.08 (d, 1H,
J = 7.2 Hz, Ar‐H), 8.12–8.18 (m, 3H, Ar‐H), 8.20–8.31 (m,
7). Anal. Calcd for C H N O (%): C, 74.43; H, 2.89; N,
10.59. Found (%): C, 74.68; H, 3.10; N, 10.65.
41
19 5 5
3
H, Ar‐H), 8.45 (t, 1H, J = 7.2 Hz, Ar‐H), 8.61 (d, 1H,
4
.7.6 | Spiro[benzo[a]benzo[6,7]chromeno
13
J = 7.6 Hz, Ar‐H), 9.17–9.29 (m, 1H, Ar‐H). C NMR
100 MHz, DMSO‐d , δ, ppm): 45.3, 112.7, 115.4, 117.0,
[
2,3‐c]phenazine‐17,6′‐indeno[1,2‐b]pyrido[3,2‐
(
6
e]pyrazine]‐11,16‐dione (8f)
Brown solid; yield 79%, 0.487 g; m.p. 269–271 °C. FT‐IR
(KBr, νmax, cm ): 3015, 1714, 1660, 1583, 1531, 1495,
1327, 1283, 1185, 1038, 758. H NMR (400 MHz, DMSO‐
d6, δ, ppm): 7.39 (d, 1H, J = 6.4 Hz, Ar‐H), 7.63 (t, 1H,
J = 8.4 Hz, Ar‐H), 7.69–7.80 (m, 3H, Ar‐H), 7.85–7.92 (m,
3H, Ar‐H), 7.98–8.16 (m, 5H, Ar‐H), 8.23 (d, 1H,
J = 8.8 Hz, Ar‐H), 8.30 (d, 1H, J = 8.4 Hz, Ar‐H), 8.36–
1
1
1
1
22.2, 124.1, 125.3, 125.7, 127.1, 128.4, 129.2, 129.3,
29.4, 129.5, 130.0, 130.3, 130.4, 130.9, 132.4, 132.7,
33.8, 134.1, 136.9, 138.7, 139.1, 139.5, 140.9, 141.6,
−
1
1
42.0, 148.4, 151.7, 153.7, 155.8, 158.4, 177.1, 178.6. MS
+
(
m/z, %): 616 (M , 8). Anal. Calcd for C H N O (%): C,
4
1 20 4 3
7
9
9.86; H, 3.27; N, 9.09. Found (%): C, 80.09; H, 3.12; N,
.26.
8
1
.41 (m, 1H, Ar‐H), 8.52–8.55 (m, 1H, Ar‐H), 8.62 (dd,
H, J = 8.0 Hz, J = 1.6 Hz, Ar‐H), 9.09–9.11 (m, 1H,
4
.7.4 | 8′‐Methylspiro[benzo[a]benzo[6,7]
1
2
chromeno[2,3‐c]phenazine‐17,11′‐indeno[1,2‐b]
quinoxaline]‐11,16‐dione (8d)
13
Ar‐H). C NMR (100 MHz, DMSO‐d , δ, ppm): 48.4,
6
1
11.9, 116.0, 117.5, 121.5, 122.4, 122.7, 123.2, 124.1,
Brown solid; yield 85%, 0.536 g; m.p. 182–184 °C. FT‐IR
124.2, 125.6, 126.1, 127.8, 128.1, 128.3, 128.9, 129.4,
129.6, 130.2, 130.5, 131.1, 131.3, 133.2, 134.0, 135.0,
137.8, 139.1, 139.7, 140.3, 141.1, 147.9, 151.8, 158.5,
−
1
(
1
KBr, νmax, cm ): 3045, 1715, 1661, 1589, 1535, 1447,
326, 1263, 1192, 1005, 756. H NMR (400 MHz, DMSO‐
1
+
d , δ, ppm): 3.03 (s, 3H, CH ), 7.47–7.62 (m, 1H, Ar‐H),
159.3, 176.8, 178.2. MS (m/z, %): 617 (M , 5). Anal. Calcd
6
3
7.66–7.74 (m, 2H, Ar‐H), 7.77–7.93 (m, 7H, Ar‐H), 8.03
for C H N O (%): C, 77.79; H, 3.10; N, 11.34. Found
4
0 19 5 3
(d, 1H, J = 8.4 Hz, Ar‐H), 8.07–8.12 (m, 2H, Ar‐H), 8.16–
(%): C, 78.04; H, 3.38; N, 11.51.
8
.23 (m, 3H, Ar‐H), 8.43–8.49 (m, 1H, Ar‐H), 8.63 (d, 1H,
13
J = 7.6 Hz, Ar‐H), 9.19 (d, 1H, J = 8.4 Hz, Ar‐H).
C
4
.7.7 | 17‐(3,4‐dimethoxyphenyl)‐11H–benzo
NMR (100 MHz, DMSO‐d , δ, ppm): 21.3, 47.6, 111.7,
6
[
a]benzo[6,7]chromeno[2,3‐c]phenazine‐11,16
1
1
1
1
1
12.7, 115.9, 120.9, 121.5, 122.0, 122.9, 124.1, 125.9,
28.3, 128.4, 128.8, 129.2, 129.8, 130.0, 130.2, 130.4,
30.6, 131.5, 132.3, 132.4, 132.6, 134.0, 136.8, 139.0,
40.2, 140.3, 140.6, 141.5, 142.8, 147.6, 150.5, 154.8,
(17H)‐dione (9j)
Brown solid; yield 85%, 0.468 g; m.p. 320–321 °C. FT‐IR
(KBr, νmax, cm ): 2995, 1682, 1635, 1588, 1509, 1455,
1358, 1264, 1161, 1022, 757. H NMR (400 MHz,
−
1
+
1
56.1, 158.3, 177.4, 177.6. MS (m/z, %): 630 (M , 3). Anal.

1
2 of 13
ABBASI POUR ET AL.
DMSO‐d , δ, ppm): 3.52, 3.71 (s, 6H, 2OCH ), 5.95 (s, 1H,
[6] A. Domling, W. Wang, K. Wang, Chem. Rev. 2012, 112, 3083.
6
3
CH), 6.64 (d, 1H, J = 8.8 Hz, Ar‐H), 6.81 (dd, 1H,
J = 8.4 Hz, J = 2.0 Hz, Ar‐H), 7.35 (d, 1H, J = 2.0 Hz,
[7] E. Ruijter, R. Scheffelaar, R. V. A. Orru, Angew. Chem. Int. Ed.
2011, 50, 6234.
1
2
Ar‐H), 7.76 (t, 1H, J = 7.6 Hz, Ar‐H), 7.89–8.00 (m, 5H,
Ar‐H), 8.06 (dd, 1H, J = 7.6 Hz, J = 0.8 Hz, Ar‐H), 8.25
[8] M. Shiri, Chem. Rev. 2012, 112, 3508.
1
2
[9] N. Isambert, M. D. M. S. Duque, J.‐C. Plaquevent, Y. Genisson, J.
Rodriguez, T. Constantieux, Chem. Soc. Rev. 2011, 40, 1347.
(d, 1H, J = 7.6 Hz, Ar‐H), 8.30 (d, 1H, J = 8.0 Hz, Ar‐H),
8
.44 (d, 1H, J = 7.6 Hz, Ar‐H), 8.66 (d, 1H, J = 8.0 Hz,
[
10] J. Ligon, S. Dwight, P. Hammer, N. Torkewitz, D. Hofmann, H.
1
3
Ar‐H), 9.19 (d, 1H, J = 8.0 Hz, Ar‐H) ppm. C NMR
100 MHz, DMSO‐d , δ, ppm): 33.0, 55.2, 55.4, 111.5,
Kempf, K. Pee, Pest Manag. Sci. 2000, 56, 688.
(
6
[11] C. Neves‐Pinto, V. Malta, M. Pinto, R. Santos, S. Castro, A. Pinto,
J. Med. Chem. 2002, 45, 740.
1
1
1
1
13.5, 115.3, 120.2, 122.3, 124.6, 124.9, 125.6, 128.7,
29.1, 129.2, 129.8, 129.9, 130.2, 130.5, 130.7, 130.8,
30.9, 131.5, 135.3, 135.9, 140.2, 140.6, 141.5, 145.8,
[12] M. Makgatho, R. Anderson, J. O'Sullivan, T. Egan, J. Freese, N.
Cornelius, C. Van Rensburg, Drug Dev. Res. 2000, 50, 195.
47.3, 154.5, 156.1, 177.2, 178.1 ppm. MS (m/z, %): 550
[
[
13] A. Hasaninejad, S. Firoozi, Mol. Divers. 2013, 17, 499.
+
(M , 9). Anal. Calcd for C H N O (%): C, 76.35; H,
3
5 22 2 5
14] A. Hasaninejad, S. Firoozi, F. Mandegani, Tetrahedron Lett. 2013,
4
.03; N, 5.09. Found (%): C, 76.50; H, 4.19; N, 5.18.
5
4, 2791.
15] L. E. Seitz, W. J. Suling, R. C. Reynolds, J. Med. Chem. 2002, 45,
604.
[
5
4
.7.8 | 17‐(4‐hydroxyphenyl)‐11H–benzo[a]
benzo[6,7]chromeno[2,3‐c]phenazine‐11,16
17H)‐dione (9 k)
[16] M. M. Badran, A. A. Moneer, H. M. Refaat, A. A. El‐Malah,
J. Chin. Chem. Soc. 2007, 54, 469.
(
[
17] G. Aguirre, H. Cerecetto, R. Di Maio, M. González, M. E. M.
Alfaro, A. Jaso, B. Zarranz, M. Á. Ortega, I. Aldana, A. Monge‐
Vega, Bioorg. Med. Chem. Lett. 2004, 14, 3835.
Yellow solid; yield 83%, 0.420 g; m.p. 301–303 °C. FT‐IR
−
1
(KBr, νmax, cm ): 3030, 1685, 1631, 1571, 1506, 1435,
1
1
364, 1287, 1164, 1084, 760. H NMR (400 MHz, DMSO‐
[
[
18] A. Hasaninejad, N. Golzar, A. Zare, J. Heterocycl. Chem. 2013, 50,
d6, δ, ppm): 5.82 (s, 1H, CH), 6.50 (d, 2H, J = 8.8 Hz, Ar‐
H), 7.27 (d, 2H, J = 8.4 Hz, Ar‐H), 7.22 (t, 1H,
J = 7.6 Hz, Ar‐H), 7.82–7.95 (m, 6H, Ar‐H), 8.01 (dd, 1H,
6
08.
19] J. G. Tangmouo, A. L. Meli, J. Komguem, V. Kuete, F. N.
Ngounou, D. Lontsi, V. P. Beng, M. I. Choudhary, B. L.
Sondengam, Tetrahedron Lett. 2006, 47, 3067.
J = 7.2 Hz, J = 0.8 Hz, Ar‐H), 8.19 (td, 2H, J = 8.4 Hz,
1
2
1
J2 = 1.6 Hz, Ar‐H), 8.34 (d, 1H, J = 7.6 Hz, Ar‐H), 8.56
d, 1H, J = 8.0 Hz, Ar‐H), 9.11 (d, 1H, J = 7.6 Hz, Ar‐H)
[
20] M. C. M. Iqbal, U. L. B. Jayasinghe, H. M. T. B. Herath, K. B.
(
Wijesekara, Y. Fujimoto, Phytoparasitica 2004, 32, 119.
13
ppm. C NMR (100 MHz, DMSO‐d , δ, ppm): 32.5,
6
[21] T. Narender, S. Gupta, Bioorg. Med. Chem. Lett. 2009, 14, 3913.
1
1
1
1
14.5, 115.4, 116.3, 122.1, 124.5, 124.8, 125.5, 128.7,
28.8, 128.9, 129.0, 129.7, 129.9, 130.1, 130.4, 130.7,
30.8, 131.4, 133.9, 135.3, 139.9, 140.1, 140.5, 141.5,
[
22] V. Lakshmi, K. Pandey, A. Kapil, N. Singh, M. Samant, A. Dube,
Phytomedicine 2007, 14, 36.
[
23] L. Alvey, S. Prado, V. Huteau, B. Saint‐Joanis, S. Michel, M. Koch,
S. T. Cole, F. Tillequin, Y. L. Janin, Bioorg. Med. Chem. 2008, 16,
8264.
45.7, 155.7, 155.8, 177.2, 177.9 ppm. MS (m/z, %): 506
+
(M , 12). Anal. Calcd for C H N O (%): C, 78.25; H,
3
3 18 2 4
3
.58; N, 5.53. Found (%): C, 78.48; H, 3.64; N, 5.29.
[
[
[
24] R. Rios, Chem. Soc. Rev. 2012, 41, 1060.
25] G. S. Singh, Z. Y. Desta, Chem. Rev. 2012, 112, 6104.
ACKNOWLEDGEMENT
26] K. Murai, H. Komatsu, R. Nagao, H. Fujioka, Org. Lett. 2012, 14,
7
72.
We gratefully acknowledge financial support from the
Research Council of the University of Science and Arts,
Yazd, Iran.
[
27] J. Sun, Y. J. Xie, C. G. Yan, J. Org. Chem. 2013, 78, 8354.
[
28] T. Shen, Z. Fu, F. Che, H. Dang, Y. Lin, Q. Song, Tetrahedron Lett.
2
015, 56, 1072.
29] J. Yu, Y. Zhou, T. Shen, W. Mao, K. Chen, Q. Song, J. Chem. Res.
013, 37, 365.
[30] H. Chen, D. Shi, J. Comb. Chem. 2010, 12, 571.
[
REFERENCES
2
[
[
[
[
1] M. D. Burke, S. L. Schreiber, Angew. Chem. Int. Ed. 2004, 43, 46.
[
[
[
31] L. Ma'mani, M. Sheykhan, A. Heydari, M. Faraji, Y. Yamini, Appl.
Catal. 2010, 377, 64.
2] D. R. Spring, Org. Biomol. Chem. 2003, 1, 3867.
3] R. L. Strausberg, S. L. Schreiber, Science 2003, 300, 294.
4] D. A. Horton, G. T. Bourne, M. L. Smythe, Chem. Rev. 2003, 103,
32] J. Deng, L. P. Mo, F. Y. Zhao, L. L. Hou, L. Yang, Z. H. Zhang,
Green Chem. 2011, 13, 2576.
8
93.
33] N. Koukabi, E. Kolvari, M. A. Zolfigol, A. Khazaei, B. S.
Shaghasemi, B. Fasahati, Adv. Synth. Catal. 2012, 354, 2001.
[5] L. F. Tietze, G. Brasche, K. Gerike, Domino Reactions in Organic
Chemistry, Wiley‐VCH, Weinheim 2006.
[34] E. Rafiee, S. Eavani, Green Chem. 2011, 13, 2116.

ABBASI POUR ET AL.
13 of 13
[
35] Y. H. Liu, J. Deng, J. W. Gao, Z. H. Zhang, Adv. Synth. Catal.
012, 354, 441.
36] S. Shylesh, V. Schunemann, W. R. Thiel, Angew. Chem. Int. Ed.
010, 49, 3428.
[46] S. Sobhani, M. S. Ghasemzade, M. Honarmand, Catal. Lett. 2014,
144, 1515.
2
[
[47] B. D. Pearson, R. A. Mitsch, N. H. Cromwell, J. Org. Chem. 1962,
27, 1674.
2
[
[
37] L. Mamani, A. Heydari, M. Sheykhan, Appl. Catal. A2010, 384, 122.
38] R. Mohebat, A. Yazdani Elah Abadi, A. Soltani, M. Saghafi,
SUPPORTING INFORMATION
Arkivoc 2016, iv, 1.
Additional Supporting Information may be found online in
the supporting information tab for this article.
[
[
[
[
[
39] R. Mohebat, A. Yazdani Elah Abadi, M. T. Maghsoodlou, Res.
Chem. Intermed. 2016, 42, 6039.
40] A. Yazdani‐Elah‐Abadi, R. Mohebat, M. T. Maghsoodlou, RSC
Adv. 2016, 6, 84326.
How to cite this article: Abbasi Pour S, Yazdani‐
Elah‐Abadi A, Afradi M. Nanomagnetically modified
thioglycolic acid (γ‐Fe O @SiO ‐SCH CO H):
41] A. Yazdani Elah Abadi, M. T. Maghsoodlou, R. Heydari, R.
Mohebat, Res. Chem. Intermed. 2016, 42, 1227.
2
3
2
2
2
42] A. Yazdani‐Elah‐Abadi, R. Mohebat, M. Kangani, J. Chem. Res.
Efficient and reusable green catalyst for the one‐pot
domino synthesis of spiro[benzo[a]benzo[6,7]
chromeno[2,3‐c]phenazine] and benzo[a]benzo[6,7]
chromeno[2,3‐c]phenazines. Appl Organometal Chem.
2
016, 40, 722.
43] A. Yazdani‐Elah‐Abadi, M. T. Maghsoodlou, R. Mohebat, R.
Heydari, Chin. Chem. Lett. 2017, 28, 446.
[
44] K. M. Ho, P. Li, Langmuir 2008, 24, 1801.
45] K. Azizi, A. Heydari, RSC Adv. 2014, 4, 8812.
2
017;e3791. https://doi.org/10.1002/aoc.3791
[