Synthesis of 1′-aryl-2′-(2-oxoindolin-3-yl)spiro[indoline-3, 5′-pyrroline]-2,3′-dione via one-pot reaction of arylamines, acetone, and isatins

Article abstract of DOI:10.1016/j.tetlet.2012.05.023

An efficient synthetic method for 1′-aryl-2′-(2-oxoindolin-3- yl)spiro[indoline-3,5′-pyrroline]-2,3′-diones was successfully developed via the one-pot domino reaction of arylamines, acetone, and isatins in acetic acid. The reaction mechanism involved the

Full text of DOI:10.1016/j.tetlet.2012.05.023

Tetrahedron Letters 53 (2012) 3647–3649
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Tetrahedron Letters
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Synthesis of 10-aryl-20-(2-oxoindolin-3-yl)spiro[indoline-3,50-pyrroline]-2,30-
dione via one-pot reaction of arylamines, acetone, and isatins
⇑
Yan Sun, Jing Sun, Chao-Guo Yan
College of Chemistry & Chemical Engineering, Yangzhou University, Yangzhou 225002, China
a r t i c l e i n f o
a b s t r a c t
An efficient synthetic method for 10-aryl-20-(2-oxoindolin-3-yl)spiro[indoline-3,50-pyrroline]-2,30-diones
was successfully developed via the one-pot domino reaction of arylamines, acetone, and isatins in acetic
acid. The reaction mechanism involved the sequential Michael addition and ring closure of the in situ
formed 3-N-aryliminoisatin and isatylidene acetone.
Article history:
Received 5 March 2012
Revised 2 May 2012
Accepted 4 May 2012
Available online 10 May 2012
Ó 2012 Elsevier Ltd. All rights reserved.
Keywords:
One-pot reaction
Domino reaction
Michael addition
Isatin
Spiro compound
The spirooxindole system is the core structure of many pharma-
cological agents and natural alkaloids.1,2 As a consequence, a num-
ber of methods have been reported for the preparation of
spirooxindole-fused heterocycles.3,4 Recent synthetic methods to
access spirocyclic oxindoles include cycloaddition,5–7 Morita–Bay-
lis–Hillman reaction,8,9 and other cyclization reactions.10 Isatin
derivatives are important precursors of spirocyclic oxindoles and
many naturally occurring oxindole alkaloids.11,12 In the past few
years the multicomponent reactions or domino reactions based
on the versatile reactivity of isatins have become the most widely
used methods for the synthesis of various spirooxindoles.13–16 As
our program on new multicomponent reactions for the synthesis
of heterocyclic compounds,17,18 herein we wish to report the effi-
cient synthesis of the novel functionalized 10-aryl-20-(2-oxoindo-
lin-3-yl)spiro[indoline-3,50-pyrroline]-2,30-diones via the one-pot
domino reaction of arylamines, acetone, and isatins in acetic acid.
It has been known that the domino reactions of isatins with
Huisgen’s zwitterions formed in situ from isoquinoline and acety-
lenic esters have become the efficient synthetic procedures for
constructing versatile spirooxindole systems.19,20 Perumal and
coworkers successfully reported the synthesis of spiro[indole-
3,40-pyridines] derivatives by the four-component reaction of aryl-
amine, acetylenedicarboxylate, malononitrile, and isatin.21 The
publication of these works prompted us to envisage using other
functionalized isatins such as isatylidene acetone or isatylidene
chalcone to react with Huisgen’s zwitterions for spirooxindoles.
In our initial endeavor, we have investigated a one-pot three-com-
ponent reaction of isatin, acetone, and b-arylaminobutenedicarb-
oxylate, which was prepared in situ from the addition of
arylamine to acetylenedicarboxylate in acetic acid. After workup,
a yellow solid was obtained in about 40% yield. Its structure was
assigned as 10-aryl-20-(2-oxoindolin-3-yl)spiro[indoline-3,50-pyr-
roline]-2,30-dione. There is no unit of dimethyl acetylenedicarbox-
ylate in its molecule, which clearly indicated that only arylamine,
acetone, and isatin reacted as three-components to form the ob-
tained product. This interesting result encouraged us to examine
the three-component reaction of arylamine, acetone, and isatin of
catalyst, solvent, temperature, and adding sequences of substrates.
The best result was obtained by carrying out the three-component
reaction in domino type and using acetic acid. Thus p-methoxyan-
iline first reacted with isatin in acetic acid at room temperature for
2 h for the formation of the active intermediate 3-N-aryliminoisat-
in. Then second molar isatin and excess acetone were added and
the reaction proceeded smoothly at room temperature for about
3 h to give the desired 10-p-methoxyphenyl-20-(2-oxoindolin-
3-yl)spiro[indoline-3,50-pyrroline]-2,30-dione (1a) in 70% yield
(Table 1, entry 1).22 Then 5-methyl, 5-chloro-, 5-fluoroisatins and
various arylamines with different substituents were utilized in this
one-pot domino reaction under the similar reaction conditions. The
results are shown in Table 1. From these results we could see that
all the reactions proceeded smoothly to afford the corresponding
spiro compounds (1b–1k) in good yields. Arylamines with elec-
tron-donating methyl and methoxyl groups gave better yields than
those of p-chloroaniline. The structures of spiro compounds were
fully characterized by 1H and 13C NMR, HPLC/MS, HRMS, and IR
⇑
Corresponding author.
E-mail address: cgyan@yzu.edu.cn (C.-G. Yan).
0040-4039/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.tetlet.2012.05.023

3648
Y. Sun et al. / Tetrahedron Letters 53 (2012) 3647–3649
Table 1
One-pot synthesis of 10-aryl-20-(2-oxoindolin-3-yl)spiro[indoline-3,50-pyrroline]-2,30-diones
O
Ar
N
O
NH
HN
O
R
HOAc
r. t.
+
O
+ CH3COCH3
ArNH2
N
H
O
R
R
Entry
Compound
Ar
R
Yield (%)
1
2
3
4
5
6
7
8
9
1a
1b
1c
1d
1e
1f
1g
1h
1i
p-CH3OC6H4
H
CH3
Cl
F
H
CH3
F
CH3
CH3
H
70
78
71
70
62
65
64
60
70
52
56
p-CH3OC6H4
p-CH3OC6H4
p-CH3OC6H4
p-CH3C6H4
p-CH3C6H4
p-CH3C6H4
m-CH3C6H4
C6H5
10
11
1j
1k
p-ClC6H4
p-ClC6H4
CH3
O
O
HN
HOAc
r. t.
N
O +
N
H
NH2
O
(A)
O
O
HOAc
r. t.
O
O
+
O
O
N
H
N
H
(B)
O
HN
NH
O
NH
HN
N
NH
O
O
1
(C)
Scheme 1. The proposed reaction mechanism.
Figure 1. Molecular structure of spiro compound 1f.
spectra, further confirmed by single-crystal X-ray diffraction deter-
mination of compound 1e (Fig. 1). 1H NMR spectra of the 1a–1k
clearly indicated that only one diastereomer exists in the formed
product. As for example, in 1H NMR spectra of 1a, the two NH units
in two pyrrole rings show two singlets at 10.50 and 10.31 ppm. The
proton at 20-position shows a doublet at 5.08 ppm and two protons
at 40-position display two doublets at 2.79 and 2.68 ppm with
germinal coupling constants J = 18.0 Hz. The proton at 3-position
in 2-oxoindolin-3-yl group also shows a doublet at 3.45 ppm.
To evaluate the scope of this three-component reaction further,
other reactive ketones such as butanone, 1-phenylacetone, and
1,3-diphenylacetone were also tested. But the results of these reac-
tions were very disappointing. Only 3-N-aryliminoisatin could be
separated from the reaction mixture. At present an exact mecha-
nism for the formation of spiro[indoline-3,50-pyrroline]-2,30-diones
is not very clear. However, in order to explain this straightforward
domino reaction, a reasonable possibility is shown in Scheme 1. At
first isatin condensed with arylamine to give 3-N-aryliminoisatin
(A) in the presence of acetic acid. Secondly isatin reacted with ace-
tone resulting in isatylidene acetone (B) under the catalysis of ace-
tic acid. Thirdly the nucleophilic addition of active methyl group of
intermediate (B) to the imino group of intermediate (A) gave ad-
duct (C). Then the intramolecular nucleophilic addition of amino
group to the butene-1,4-dione unit in adduct (C) produced the final
spiro compound 1. The reaction of the previously prepared 3-N-p-
methylphenyliminoisatin (A) with isatylidene acetone (B) or its
undehydrated precursor 3-hydroxy-3-acetonylisatin in acetic acid
at room temperature for several hours gave the expected spiro
compound 1e in moderate yield. This result gives a strong support
to our above proposed reaction mechanism.
In conclusion, we have described a new one-pot sequential
reaction of arylamines, acetone, and isatins, and found an efficient
procedure for the synthesis of spiro[indoline-3,50-pyrroline]-2,30-
dione. The reaction mechanism was briefly discussed. Prominent
among the advantages of this new method are operational
simplicity, good yields of products in short reaction times, and easy
work-up procedures. Further expansion of the reaction scope and
synthetic applications of this methodology are in progress in our
laboratory.
Acknowledgments
This work was financially supported by the National Natural
Science Foundation of China (Grant No. 21172189) the Priority
Academic Program Development of Jiangsu Higher Education
Institutions.

Y. Sun et al. / Tetrahedron Letters 53 (2012) 3647–3649
3649
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Supplementary data
Supplementary data (crystallographic data 1e (CCDC has been
deposited at the Cambridge Crystallographic Database Centre)
associated with this article can be found, in the online version, at
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22. General procedure for the one-pot reactions of arylamines, acetone, and isatins: A
mixture of an arylamine (2.0 mmol) and isatin (4.0 mmol) in 10.0 mL acetic
acid was stirred at room temperature for 2 h. Then acetone (5.0 mL) was added.
The reaction mixture was stirred at room temperature for another 2–3 h.
After adding water (30 mL), the resulting precipitate was collected by filtration
and washed with a small portion of cold ethanol to give pure product for
analysis.
Compound 1a: white solid, 70%, m.p. 238–241 °C; 1H NMR (600 MHz, DMSO-
d6) d: 10.50 (s, 1H, NH), 10.31 (s, 1H, NH), 7.62 (d, J = 7.2 Hz, 1H, ArH), 7.52–
7.51 (m, 1H, ArH), 7.23 (t, J = 7.2 Hz, 1H, ArH), 7.15–7.10 (m, 2H, ArH), 6.97–
6.93 (m, 3H, ArH), 6.74 (d, J = 7.2 Hz, 1H, ArH), 6.68–6.65 (m, 3H, ArH), 5.08 (d,
J = 3.0 Hz, 1H, CH), 3.61 (s, 3H, OCH3), 3.45 (br, 1H, CH), 2.79 (d, J = 18.0 Hz, 1H,
CH), 2.68 (d, J = 18.0 Hz, 1H, CH); 13C NMR (150 MHz, DMSO-d6) d: 209.3, 199.7,
191.3, 182.7, 180.8, 178.8, 175.7, 156.8, 143.3, 142.5, 135.7, 129.7, 128.4, 127.9,
126.6, 126.2, 124.6, 124.4, 122.3, 121.1, 113.9, 110.1, 109.1, 86.9, 69.3, 66.9,
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55.0, 46.5; IR (KBr) t: 3184, 3084, 3033, 2900, 2837, 1762, 1712, 1620, 1510,
1469, 1331, 1289, 1243, 1195, 1124, 1031, 982, 940, 834, 776 cmꢀ1; MS (m/z):
438.31 ([M–H]ꢀ, 100%); HRMS (ESI) Calcd for C26H20N3O4 ([MꢀH]ꢀ): 438.1459.
Found: 438.1460.
Compound 1b: white solid, 78%, m.p. 262–263 °C; 1H NMR (600 MHz, DMSO-
d6) d: 10.41 (s, 1H, NH), 10.21 (s, 1H, NH), 7.34 (s, 1H, ArH), 7.27 (br s, 1H, ArH),
7.04 (d, J = 7.8 Hz, 1H, ArH), 6.91–6.90 (m, 3H, ArH), 6.66–6.64 (m, 2H, ArH),
6.61 (d, J = 7.8 Hz, 1H, ArH), 6.58 (d, J = 7.8 Hz, 1H, ArH), 5.02 (d, J = 4.2 Hz, 1H,
CH), 3.62 (s, 3H, OCH3), 3.46 (br, 1H, CH), 2.77 (d, J = 18.0 Hz, 1H, CH), 2.67 (d,
J = 18.0 Hz, 1H, CH), 2.35 (s, 3H, CH3), 2.26 (s, 3H, CH3); 13C NMR (150 MHz,
DMSO-d6) d: 209.2, 178.8, 175.7, 156.5, 140.9, 140.0, 136.1, 131.2, 129.9, 129.6,
18.8, 128.0, 126.2, 125.3, 124.8, 113.8, 109.9, 108.8, 69.2, 66.8, 55.0, 46.7, 20.8,
20.6; IR (KBr) t: 3164, 3031, 2859, 1762, 1708, 1625, 1510, 1490, 1326, 1243,
1126, 1033, 815 cmꢀ1; MS (m/z): 466.29 ([MꢀH]ꢀ, 100%); HRMS (ESI) Calcd for
C
28H24N3O4 ([MꢀH]ꢀ): 466.1772. Found: 466.1772.
Compound 1e: white solid, 62%, m.p. 232–235 °C; 1H NMR (600 MHz, DMSO-
d6) d: 10.52 (s, 1H, NH), 10.33 (s, 1H, NH), 7.64 (d, J = 7.2 Hz, 1H, ArH), 7.53 (d,
J = 6.6 Hz, 1H, ArH), 7.26 (t, J = 7.2 Hz, 1H, ArH), 7.17–7.12 (m, 2H, ArH), 6.96 (t,
J = 7.2 Hz, 1H, ArH), 6.92–6.91 (m, 2H, ArH), 6.88–6.86 (m, 2H, ArH), 6.75 (d,
J = 7.8 Hz, 1H, ArH), 6.71 (d, J = 7.8 Hz, 1H, ArH), 5.12–5.11 (m, 1H, CH), 3.50 (s,
1H, CH), 2.81 (d, J = 18.0 Hz, 1H, CH), 2.66 (d, J = 18.0 Hz, 1H, CH), 2.13 (s, 3H,
CH3); 13C NMR (150 MHz, DMSO-d6) d: 209.0, 178.4, 175.7, 143.4, 142.4, 140.7,
134.0, 129.8, 129.3, 128.7, 127.9, 126.1, 124.6, 124.5, 123.9, 122.4, 121.1, 110.2,
12. (a) Gao, S. J.; Tsai, C. H.; Tseng, C.; Yao, C. F. Tetrahedron 2008, 64, 9143–9149;
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109.2, 69.1, 66.4, 46.5, 20.3; IR (KBr) t: 3347, 3056, 2922, 1761, 1719, 1621,
1512, 1469, 1393, 1328, 1284, 1252, 1230, 1192, 1114, 1020, 978, 928, 901,
830, 748 cmꢀ1
C
;
MS (m/z): 422.25 ([MꢀH]ꢀ, 100%); HRMS (ESI) Calcd for
26H20N3O3 ([MꢀH]ꢀ): 422.1510. Found: 422.1504.
Compound 1j: white solid, 52%, m.p. 248–251 °C; 1H NMR (600 MHz, DMSO-
d6) d: 10.54 (s, 1H, NH), 10.40 (s, 1H, NH), 7.62–7.61 (m, 1H, ArH), 7.43–7.42
(m, 1H, ArH), 7.28 (br s, 1H, ArH), 7.17–7.10 (m, 4H, ArH), 6.87 (br s, 3H, ArH),
6.74–6.70 (m, 2H, ArH), 5.13 (s, 1H, CH), 3.67 (s, 1H, CH), 2.88 (d, J = 18.0 Hz,
1H, CH), 2.78 (d, J = 18.0 Hz, 1H, CH); 13C NMR (150 MHz, DMSO-d6) d: 208.7,
178.0, 175.7, 143.3, 142.3, 130.0, 128.7, 128.6, 128.5, 127.9, 125.4, 124.6, 124.5,
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122.6, 121.1, 110.4, 109.2, 69.2, 66.1, 46.5; IR (KBr) t: 3345, 1762, 1717, 1622,
1490, 1469, 1391, 1329, 1285, 1252, 1196, 1090, 1012, 978, 930, 900,
841 cmꢀ1
C
;
MS (m/z): 442.25 ([MꢀH]ꢀ, 100%); HRMS (ESI) Calcd for
25H17ClN3O3 ([MꢀH]ꢀ): 442.0964. Found: 442.0958.