An environmental friendly approach for the synthesis of spiro[indoline-3',2-quinazoline]2',4(3H)-dione using 1-methylimidazolium hydrogen sulfate, as reusable catalyst

Article abstract of DOI:10.1002/jccs.201300147

A facile and environmentally benign procedure for the synthesis of 3-aryl-1H-spiro[indoline-3',2-quinazoline] 2',4(3H)-dione from isatoic anhydride, aromatic amines and isatin derivatives in Bronsted acidic ionic liquid, 1-methylimidazoliumhydrogen sulfate, was reported. The ability to reuse the ionic liquid, the high yield, short reaction time and ease of purification are the important features of this process.

Full text of DOI:10.1002/jccs.201300147

JOURNAL OF THE CHINESE
CHEMICAL SOCIETY
Communication
An Environmental Friendly Approach for the Synthesis of
Spiro[indoline-3¢,2-quinazoline]2¢,4(3H)-dione Using 1-Methylimidazolium Hydrogen
Sulfate, as Reusable Catalyst
Hassan Kefayati,a,* Masoumeh Vazifehb and Reyhaneh Kazemi-Radc
aDepartment of Chemistry, Science and Research Branch, Islamic Azad University, Guilan, Iran
bDepartment of Chemistry, Rasht Branch, Islamic Azad University, Rasht, Iran
cDepartment of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran
(Received: Mar. 23, 2013; Accepted: Jun. 27, 2013; Published Online: ??; DOI: 10.1002/jccs.201300147)
A facile and environmentally benign procedure for the synthesis of 3-aryl-1H-spiro[indoline-3¢,2-quin-
azoline]2¢,4(3H)-dione from isatoic anhydride, aromatic amines and isatin derivatives in Brønsted acidic
ionic liquid, 1-methylimidazolium hydrogen sulfate, was reported. The ability to reuse the ionic liquid, the
high yield, short reaction time and ease of purification are the important features of this process.
Keywords: Isatin; Isatoic anhydrid; Spiro[indoline-quinazoline]one; 1-Methylimidazolium hydro-
gen sulfate; Multi component reaction.
Heterocycles containing the quinazoline ring are im-
portant targets in synthetic and medicinal chemistry be-
cause this fragment is a key moiety in numerous biologi-
cally active compounds. Recently, much attention has been
focused on the synthesis of 2,3-dihydroquinazolin-4(3H)-
ones, because of their interesting biological and pharma-
ceutical activities, such as antifertility, antibacterial, anti-
fungal, analgesic, antitumor, anticancer and herbicide.1-3
The indole moiety is probably the most well-known
heterocycle, a common and important feature of a variety
of natural products and medicinal agents.4 Also, the C-3-
spiro-oxindol framework system is the core structure of
many pharmacological agents and natural alkaloids.5 Fur-
thermore, it has been reported that sharing the indole 3-car-
bon atom in the formation of spiroindoline derivatives can
highly enhance biological activity.6
line-3¢,2-quinazoline]2¢,4(3H)-dione (4a-o) from isatoic
anhydride 1, aromatic amines 2a–o and isatin derivatives
using [HMIm]HSO4, as a catalyst (Scheme I).
Synthesis of 1H-spiro[indoline-3¢,2-quin-
azoline]-2¢,4(3H)-diones
Scheme I
Owing to the versatile biological activities of 2,3-di-
hydroquinazoline-4(3H)-ones numerous classical methods
for the synthesis of these compounds have been re-
ported.10-14 Recently, synthesis of 1H-spiro[indoline-3¢,2-
quinazoline]-2¢,4(3H)-dione via a reductive cyclization of
2-nitrobenzamid with isatin in presence of SnCl2.2H2O
was reported.15 Also, Mohammadi et al. have reported the
synthesis of the same compounds by refluxing of primary
amines, isatin and isatoic anhydride16 or 2-amino-N-phen-
ylbenzamide17 in the presence of alum (KAl(SO4).12H2O)
as catalyst in EtOH.
In recent years, ionic liquids have attracted intensive
interests as a possible replacement of traditional solvents
and catalyst for organic reactions, particularly in the area of
green chemistry, due to their advantageous properties, in-
cluding negligible vapor pressure and high thermal and
chemical stability.7
In continuation of our efforts for the synthesis of
spiro[oxindole-quinazoline]8 and our interest in using
Brønsted acidic ionic liquid, 1-methylimidazolium hydro-
gen sulfate ([HMIm]HSO4 as an effective catalyst for the
synthesis of organic compound,9 herein, a facile procedure
was introduced for the synthesis of 3-aryl-1H-spiro[indo-
However, there are disadvantages for these reports
due to long reaction time (6-11 h) and use of unrecoverable
solvent and catalyst. One of the most important strategies
can be used to overcome these problems is to perform these
reactions in the presence of ionic liquids.
* Corresponding author. Tel.: +98 131 3462215; Fax: +98 131 3462233; P. O. Box: 41335-3516; E-mail: kefayati@iaurasht.ac.ir,
haskefayati@gmail.com
J. Chin. Chem. Soc. 2013, 60, 000-000
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1

Communication
Kefayati et al.
Table 1. Efects of the type and amount of ionic liquid on the
formation of 4a[a]
In order to find the optimum conditions, for the for-
mation of 3-phenyl-1H-spiro[indoline-3¢,2-quinazoline]-
2¢,4(3H)-dione (4a), we study the reaction of isatoic anhy-
dride (1 mmol), aniline (1.2 mmol) and isatin (1 mmol) in
the presence of 0.5 mmol of various ionic liquids such as 1-
buthyl-3-methyimidazolium bromide ([BMIm]Br), 1-bu-
thyl-3-methyimidazolium hydrogen sulfate ([BMIm]HSO4),
1-methyl-2-pyrolidonium hydrogen sulfate ([NMP]HSO4)
at 90 °C (Table 1, entry 1-3). The results show that, after
three hours trace amount of products were obtained. How-
ever, when the reaction was carried out in the presence of
[HMIm]HSO4, 4a was obtained in good yields after two
hours (Table 1, entry 4).
Entry Ionic Liquid (mmol)
T (°C)
t (min) Yield (%)
1
[BIMm]Br (0.5)
90
90
180
180
180
120
100
75
trace
trace
trace
91
2
[BMIm]HSO4 (0.5)
[NMP]HSO4 (0.5)
[HMIm]HSO4 (0.5)
[HMIm]HSO4 (0.5)
[HMIm]HSO4 (0.5)
[HMIm]HSO4 (0.5)
[HMIm]HSO4 (0.25)
[HMIm]HSO4 (0.75)
[HMIm]HSO4 (1.0)
3
90
4
90
5
100
110
120
100
100
100
94
6
82
7
60
75
8
120
90
81
9
84
10
90
78
[a] Reaction conditions: Isatoicanhydrid (1 mmol), aniline (1.2
mmol), isatin (1 mmol), ionic liquid [HMIm]HSO4.
The amount of [HMIm]HSO4 and temperature of re-
action was examined, and the results were summarized in
Table 1 (entry 4-10). It could be seen that 0.5 mmol
[HMIm]HSO4 at 100 °C gave the best yield (94%) at least
time (Table 1, entry 5).
Proposed mechanism for the synthesis of
1H-spiro[indoline-3¢,2-quinazoline]-
2¢,4(3H)-diones
Scheme II
After optimizing the conditions, we next evaluated
the efficiency and versatility of the [HMIm]HSO4 as cata-
lyst for the preparation of other spiro[indoline-3¢,2-quin-
azoline]-2¢,4(3H)-dione derivatives by using a variety of
structurally diverse anilines and isatines. In all cases stud-
ied, the reaction proceeded smoothly to give the corre-
sponding products 4a-o in good to excellent yield at least
time (Table 2).
A comparison of the present method with other re-
ported in literature are shown that not only the desired
products were obtained in better yields, but also the time of
reactions were reduced to a remarkable extent, that show
the merit of the present work in comparison with reported
results in literature16 (Table 2). Thus, the [HMIm]HSO4 act
as a suitable catalytic medium with to reaction time and
yield of the products.
In the end of reaction, the ionic liquid was easily sep-
arated from the reaction medium by washing with water.
After washing the solid products with water completely,
the water containing ionic liquid (ionic liquid is soluble in
water) was evaporated under reduced pressure and ionic
liquid was recovered and reused. Table 2 shows that no
considerable change in the activity of the ionic liquid was
observed when it reused over three successive runs (Table
2, product 4a).
[HMIm]HSO4 can activate the carbonyl groups of isatoic
anhydrid and isatin via hydrogen bonding between the car-
bonyl group of isatoic anhydrid or isatin and the cationic
(N+-H) or ionic component (SO4 -H) of ionic liquid. The
-
reaction proceeds via a cascade of condensation reactions
involving formation of the intermediate 5, which is formed
in situ by reaction of aniline 2 with the activated carbonyl
group isatoic anhydride 1. The intermediate 5 then reacted
with C-3 carbonyl of isatin to give the intermediate 6. This
intermediate undergoes a cyclocondensation reaction to af-
We have not established the exact mechanism for the
formation of spiro[indoline-3¢,2-quinazoline]-2¢,4(3H)-
diones 4, however, a reasonable suggestion is offered in
Scheme II. It is thought that, Brønsted acidic ionic liquid,
2
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CHEMICAL SOCIETY
Spiro[indoline-3¢,2-quinazoline]2¢,4(3H)-dione
Table 2. Synthesis of spiro[indoline-quinazoline]ones and comparison of efficiency 1-methylimidazolium
hydrogen sulfate with other report[a]
Founda
Reported
Products
R1
H
R2
H
R3
H
Ref.
[16]
m.p.
(°C)
time
Yield
(%)
m.p.
(°C)
time
(h)
Yield
(%)
(min)
4a
250-2
100
94
(91,90,90)[b]
251-3
8
91
4b
4c
4d
4e
4f
o-Cl
m-Cl
p-Cl
p-Br
p-Me
p-OMe
p-Et
H
H
H
H
H
H
H
H
H
H
H
293-5
282-4
265-7
215-7
273-5
267-9
295-7
298-9
295-7
80
70
87
83
91
92
90
94
86
81
94
90
92
90
92
91
-
-
-
-
-
-
-
-
H
110
120
80
264-6
8
8
7
8
-
85
86
93
92
-
[16]
H
213-5
[16]
H
271-3
[16]
4g
4h
4i
H
60
269-1
[16]
H
86
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
p-Br
m-Cl
m-Cl
p-OMe
H
5-Br
5-Br
H
35
-
-
4j
120
90
-
-
4k
4l
Ph-CH2 222-4
Ph-CH2 215-8
Ph-CH2 235-6
-
-
H
25
-
-
4m
4n
4o
H
40
-
-
p-Et
H
CH3
CH3
232-5
224-6
75
-
-
H
H
30
-
-
[a] Reaction conditions: isatoicanhydrid (1 mmol), aromatic amines (1.2 mmol), isatin (1 mmol), ionic liquid
[HIMm]HSO4 (0.5 mmol) in an oil bath at 100 ºC. [b] The yields of reaction with recycled ionic liquid after three
successive runs.
ford the corresponding spiro[indoline-3¢,2-quinazoline]-
2¢,4(3H)-diones 4 (Scheme II).
ported procedures.18,19,20 (i) Preparation of 1-Methylimidazolium
Hydrogen Sulfate:18 1-Methylimidazole (1.59 mL, 20 mmol) and
acetonitrile (5 mL) were charged into a 25 mL round-bottom
flask. Then, the mixture was stirred at 0 °C for 1 min. Stoichio-
metric amount of concentrated sulfuric acid (97%, 1.03 g/mL)
was added dropwise and the mixture stirred for 1 h at 0 °C and
then stirred for 2 h at room temperature. The [HMIm]HSO4 was
washed repeatedly with diethyl ether (2.5 mL) to remove non-
ionic residues and then it was dried in a vacuum evaporator. (ii)
Preparation of 1-butyl-3-methylimidazolium bromide:19 1-bro-
mobutane (2.2 mmol) and 1-Methylimidazole (2 mmol) are
placed in a 20 mL beaker, mixed thoroughly and the mixture is
heated intermittently in an unmodified household MW oven
(Sanyo AIF-A EM-5641) at 180 W for 3 minute (until a clear sin-
gle phase is obtained). The resulting ionic liquid is then cooled,
washed with ether (2 × 3 mL) to remove unreacted starting mate-
rials and product dried in vacuum by a rotary evaporator to obtain
the viscous clear [BMIm]Br. (iii) Preparation of [NMP][HSO4]:20
1-Methyl-2-pyrolidone (20 mmol) was charged into a 250 mL
flask with magnetic stirrer. Then equimolar concentrated sul-
phuric acid (98 wt %) was added dropwise slowly into the flask at
80 °C for 12 h. The mixture was washed with ether three times to
remove non-ionic residues and dried in vacuum by a rotary evap-
orator to obtain the viscous clear [NMP][HSO4]. (iv) Preparation
In conclusion, we have developed an efficient method
for the synthesis of spiro[indoline-3¢,2-quinazoline]-
2¢,4(3H)-diones in high yields employing Brønsted acidic
ionic liquid, 1-methylimidazolium hydrogen sulfate. The
application of an inexpensive, easily available and reusable
ionic liquid makes this method simple, clean, practical and
economically viable. Less waste, ease of product separa-
tion, descend reaction time with improved yield as com-
pared to other reported methods are advantages of the pro-
posed procedure.
EXPERIMENTAL
All reagents were purchased from Merck and Fluka and
used without further purification. Melting points were measured
on an Electro-thermal IA 9100 apparatus. IR spectra were re-
corded on KBr pellets on a Shimadzu FT-IR 8600 spectrometer.
1H and 13C NMR spectra were recorded on a Bruker 500 DRX
Avance instrument at 500 and 125 MHz. Elemental analysis were
carried out on a Thermo Finnigan Flash EA 1112 series instru-
ment.
Preparation of ionic liquids: For the present study, we pre-
pared a series of Brønsted acidic ionic liquids by the following re-
J. Chin. Chem. Soc. 2013, 60, 000-000
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3

Communication
Kefayati et al.
of [BMIm]HSO4:20 1-buthyl-3-methyimidazolium hydrogen sul-
fate was obtained by a dropwise addition of one equivalent of
concentrated sulphuric acid (98%) to solution of 1-butyl-3-meth-
ylimidazolium bromide in anhydrous methylene chloride. The re-
action proceed at room temperature for 24 h with vigorous stir-
ring. Then, the mixture was dried in vacuum by a rotary evapora-
tor to remove the HBr and solvent to obtain the viscous clear
[BMIm]HSO4.
6.68-6.70 (m, 2H), 6.89-6.91 (m, 2H), 6.99-7.07 (m, 4H), 7.30-
7.38 (m, 2H), 7.52 (d, J = 7.44 Hz, 1H), 8.07 (d, J = 7.76 Hz, 1H)
ppm; 13C NMR (125.75 MHz, DMSO-d6): d 15.0, 27.5, 29.6,
77.2, 110.6, 114.3, 114.5, 117.8, 122.1, 126.2, 127.3, 127.6,
129.0, 129.4, 130.6, 133.3, 135.8, 141.2, 142.8, 146.1, 163.6,
174.3 ppm. Anal. Calcd for C24H21N3O2: C, 75.18; H, 5.52; N,
10.96. Found: C, 75.24; H, 5.57; N, 10.90.
General Experimental Procedure for the Preparation of
Compounds 4a-o. A mixture of isatoic anhydrid (1 mmol), aro-
matic amines (1.2 mmol), isatin derivatives21 (1 mmol), ionic liq-
uid [HMIm][HSO4] (0.5 mmol) was heated in an oil bath at 100 ºC
for the appropriate times according to Table 2. After completion
of reaction, as indicated by TLC, 20 mL distilled water was
added, then the resulting solid product was filtered and dried. The
crude product was recrystallized from ethanol and dried to afford
powder compounds of 4a-o.
ACKNOWLEDGMENTS
We are grateful to the Islamic Azad University, Rasht
Branch for financial support of this work.
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4
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Spiro[indoline-3¢,2-quinazoline]2¢,4(3H)-dione
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