An efficient one-pot multi-component synthesis of 3,4,5-substituted furan-2(5H)-ones catalyzed by tetra-n-butylammonium bisulfate

Article abstract of DOI:10.1016/j.cclet.2013.06.004

A facile one-pot synthesis of 3,4,5-substituted furan-2(5H)-one derivatives from a three-component reaction of aniline derivatives, dialkylacetylenedicarboxylates and aromatic aldehydes under mild conditions using tetra-n-butylammonium bisulfate as a catalyst has been developed.

Full text of DOI:10.1016/j.cclet.2013.06.004

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CCLET-2635; No. of Pages 3
Chinese Chemical Letters xxx (2013) xxx–xxx
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Original article
An efficient one-pot multi-component synthesis of 3,4,5-substituted
furan-2(5H)-ones catalyzed by tetra-n-butylammonium bisulfate
*
Razieh Doostmohammadi, Malek Taher Maghsoodlou , Nourallah Hazeri,
Sayyed Mostafa Habibi-Khorassani
Department of Chemistry, Faculty of Science, The University of Sistan and Baluchestan, PO Box 98135-674, Zahedan, Iran
A R T I C L E I N F O
A B S T R A C T
Article history:
A facile one-pot synthesis of 3,4,5-substituted furan-2(5H)-one derivatives from a three-component
reaction of aniline derivatives, dialkylacetylenedicarboxylates and aromatic aldehydes under mild
conditions using tetra-n-butylammonium bisulfate as a catalyst has been developed.
ß 2013 Malek Taher Maghsoodlou. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All
rights reserved.
Received 25 March 2013
Received in revised form 22 May 2013
Accepted 24 May 2013
Available online xxx
Keywords:
3,4,5-Substituted furan-2(5H)-one
Aniline derivative
Dialkyl acetylenedicarboxylate
Aromatic aldehyde
Tetra-n-butylammonium bisulfate
1. Introduction
synthesis of 2(5H)-furanones promoted by SnCl2 has also been
reported by Nagarapu et al. [23].
Highly substituted furans play an important role in organic
chemistry, not only as the key structural units in many natural
products, commonsubunitsinpharmaceuticals [1–7]andflavors[8]
but also as useful building blocks in synthetic chemistry [9–13].
Theyhavealsofoundutilitiesassyntheticintermediatesorsynthons
We have recently reported the synthesis of 2(5H)-furanones in
the presence of acetic acid [24]. In continuation of our research
work on the synthesis of furan derivatives [25–33], herein we
describe a novel use of tetra-n-butylammonium bisulfate in a
multi-component reaction of aldehyde, dialkyl acetylenedicarbox-
ylates and aniline derivatives in generating furan-2(5H)-one
derivatives under mild conditions (Scheme 1).
for numerous functional groups, inter alia, carboxylic acids, a-keto-
esters, and aromatics [14]. For this reason, the efficient syntheses of
highly substitutedfurans continueto attract the interestof synthetic
chemists [15,16]. Accordingly, many strategies have beendeveloped
for the preparation of furans [17–20]. The above-mentioned
methodologies suffer from certain limitations such as long synthetic
routes, use of costly metal catalysts and highly volatile solvents, etc.
Recently Narayana et al. and Ramesh et al. developed a methodology
for the synthesis of furan-2(5H)-ones via a reaction of aromatic
amines, aldehydes and dialkyl acetylenedicarboxylate. Narayana
2. Experimental
Melting points and IR spectra of all compounds were measured
on an Electrothermal 9100 apparatus and a JASCO FTIR 460 Plus
spectrometer, respectively. The 1H NMR and 13C NMR spectra were
recorded on Bruker DRX-250 and 400 Avance instruments with
CDCl3 as a solvent. Elemental analyses were performed using a
Heraeus CHN-O-Rapid analyzer. Mass spectra were recorded on an
Agilent Technology (HP) spectrometer operating at an ionization
potential of 70 eV. All reagents and solvents obtained from Fluka
and Merck were used without further purification.
General procedures for synthesis of furan-2(5H)-ones: A mixture
of aldehyde (1 mmol), amine (1 mmol), dialkylacetylenedicarbox-
ylate (1 mmol) and tetra-n-butylammonium bisulphate was
stirred in ethanol at room temperature. After completion of the
reaction (monitored by TLC), the reaction mixture was filtrated and
washed with ethanol (10 mL Â 3) to obtain a pure product.
etal. describedthesynthesisof2(5H)-furanonesinthepresenceofb-
cyclodextrin [21]. Ramesh and Nagarajan reported the preparation
of 2(5H)-furanones via a three-component reaction of a series of
aldehydes (aromatic, heterocyclic), dialkylacetylenedicarboxylates
and 9-alkyl-9H-carbazol-3-amines in the presence of KOH [22]. The
* Corresponding author.
E-mail address: mt_maghsoodlou@chem.usb.ac.ir (M.T. Maghsoodlou).
1001-8417/$ – see front matter ß 2013 Malek Taher Maghsoodlou. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
http://dx.doi.org/10.1016/j.cclet.2013.06.004
Please cite this article in press as: R. Doostmohammadi, et al., An efficient one-pot multi-component synthesis of 3,4,5-substituted
furan-2(5H)-ones catalyzed by tetra-n-butylammonium bisulfate, Chin. Chem. Lett. (2013), http://dx.doi.org/10.1016/
j.cclet.2013.06.004

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CCLET-2635; No. of Pages 3
2
R. Doostmohammadi et al. / Chinese Chemical Letters xxx (2013) xxx–xxx
O
H
N
Table 2
CO2R
C
C
CO2R
Optimization of solvent for the synthesis of furan-2(5H)-ones from the reaction of
benzaldehyde, aniline and dimethyl acetylenedicarboxylate in the presence of
[Bu4N][HSO4] as an optimized catalyst.
RO
Ar1
Ar2
[Bu4N][HSO4]
EtOH, r.t.
H
N
O
+
+
H
Ar2
H
Ar1
O
O
Entry
Solvent
Time (h)
Isolated yield (%)
1
2
3
4a-p
1
2
3
4
5
6
7
Ethanol
5
24
24
24
24
24
24
92
55
34
–
Ethylacetate
Acetonitrile
Diethylether
n-Hexan
Scheme 1. Synthesis of furan-2(5H)-one derivatives.
59
62
80
Physical and chemical data of chosen products are demonstrated
below.
Methanol
H2O
Methyl
carboxylate (4a): White solid; 0.284 g (92%); mp 195–196 8C; IR
(KBr, cm–1): 3260, 3208, 1702, 1661; 1H NMR (400 MHz, CDCl3):
2,5-dihydro-5-oxo-2-phenyl-4-(phenylamino)furan-3-
n
d
3.77 (s, 3 H, OCH3), 5.76 (s, 1H, benzylic), 7.13 (t, 1H, J = 7.3 Hz),
7.24–7.31 (m, 7H), 7.52 (d, 2H, J = 8 Hz), 8.90 (br, NH, 1H); 13C NMR
(100 MHz, CDCl3): d165.3 and 162.7 (ester CO), 156.3, 136.1, 134.9,
129.0, 128.7, 128.6, 127.4, 125.9, 122.3, 112.8 (aromatic C), 61.6
(methoxy C), 52.1 (benzylic C); MS (positive mode, m/z (%)): 57
(100), 97 (75), 152 (24), 213 (51), 240 (39), 250 (33), 309 (M+, 44);
Anal. calcd. for C18H15NO4: C 69.89, H 4.89, N 4.53. Found: C 70.08,
H 4.97, N 4.60.
n-butylammonium bisulfate as a catalyst at room temperature in a
single step. As previously mentioned, products can be easily
separated and purified by simple filtration. Benzaldehyde, aniline,
and dimethyl acetylenedicarboxylate were taken as model
compounds for the optimization of the reaction conditions. For
this purpose, the reaction was initially carried out in ethanol using
different catalysts (Table 1). As can be seen, [Bu4N][HSO4] was
found to be the most effective catalyst for the reaction at room
temperature.
In this work, various solvents were tested to optimize the
conditions for the synthesis of compound 4a. Ethanol was found to
be the best solvent, in which the product was obtained in 92% yield
(Table 2). Here, [Bu4N][HSO4] and ethanol were finally selected as
the suitable catalyst and the solvent, respectively.
Methyl
carboxylate (4b): White solid; 0.287 g (89%); mp 173–175 8C; IR
(KBr, cm–1): 3228, 2950, 1706, 1677, 1513; 1H NMR (400 MHz,
CDCl3): 2.27 (s, 3H, CH3), 3.76 (s, 3H, OCH3), 5.72 (s, 1H, benzylic),
7.09 (d, 2H, J = 8 Hz), 7.22–7.270 (m, 5H, aromatic), 7.34 (d, 2H,
J = 8.4 Hz), 8.86 (br, 1H, NH); 13C NMR (100 MHz, CDCl3):
165.3
4-(p-tolylamino)-2,5-dihydro-5-oxo-2-phenylfuran-3-
n
d
d
and 162.8 (CO of ester), 156.4, 135.8, 135.0, 133.5, 129.6, 128.6,
128.5, 127.5, 122.4, 112.6 (C of aromatic), 61.3 (C of methoxy), 52.0
(benzylic C), 20.95 (C of methyl); MS (m/z (%)): 130 (96), 131 (21),
133 (19), 158 (39), 189 (34), 263 (14), 264 (33), 265 (12), 291 (24),
323 (M+, 100); Anal. calcd. for C19H17NO4: C 70.58, H 5.30, N 4.33.
Found: C 70.77, H 5.38, N 4.35
Under the optimized reaction conditions, the generality of the
reaction was fully investigated with different aldehydes, anilines
and dialkyl acetylenedicarboxylate to produce furan-2(5H)-one
derivatives. The results are summarized in Table 3. These results
show the effects of electron-withdrawing and electron-donating
groups on the time required and the yield of the reactions.
Benzaldehydes with electron-withdrawing groups react with
aniline more efficiently than the benzaldehydes substituted with
electron-donating groups. In our work, aliphatic aldehydes and
amines such as propanal and 1-buthyl amine did not work well
under the reaction conditions.
The structures of the new compounds in Table 3 were
established on the basis of IR, 1H NMR, 13C NMR, MS and elemental
analysis. The mass spectrum of ethyl 2-(4-cyanophenyl)-2,5-
dihydro-5-oxo-4-(phenylamino)furan-3-carboxylate (Table 3, en-
try 5) displayed the molecular ion peak at m/z 348, which is
consistent with the proposed structure. The 1H NMR spectrum of
Ethyl
furan-3-carboxylate (4e): White solid; 0.324 g (93%); mp 188–
189 8C; IR (KBr, cm–1):
3293 (NH), 2977, 2225 (CN), 1731, 1684,
1666, 1500; 1H NMR (400 MHz, CDCl3):
1.23 (t, 3H, J = 7.2 Hz,
2-(4-cyanophenyl)-2,5-dihydro-5-oxo-4-(phenylamino)-
n
d
CH3), 4.24 (q, 2H, J = 7.2 Hz, CH2), 5.82 (s, 1H, benzylic), 7.17 (t, 1H,
J = 7.2 Hz), 7.32–7.47 (m, 6H, aromatic), 7.59 (d, 2H, J = 8 Hz), 9.03
(br, 1H, NH); 13C NMR (100 MHz, CDCl3):
d 164.6, 162.5 (CO of
ester), 156.89, 140.8, 135.7, 132.5, 129.2, 128.3, 126.3, 122.1, 118.1,
112.6 (aromatic C), 112.2 (C of CN), 61.6 (methoxy), 60.8 (benzylic),
14.02 (CH3 of ethoxy). MS (m/z (%)): 93 (17), 119 (9), 155 (70), 183
(29), 228 (13), 275 (59), 302 (14), 348 (M+, 100); Anal. calcd. for
C
20H16N2O4: C 68.96, H 4.63, N 8.04. Found: C 69.10, H 4.69, N 8.11.
Table 3
3. Results and discussion
Synthesis of furan-2(5H)-one derivatives.
Entry Ar1
Ar2
R
Compound Time Yield Ref.
We have discovered a one-pot three-component condensation
reaction (MCR) for the synthesis of organic compounds using tetra-
(h)
(%)a
1
2
Ph
Ph
Ph
CH3
4a
4b
4c
4d
5
4
92
89
83
72
93
70
75
85
65
90
90
80
88
89
80
67
23
4-Me–C6H4 CH3
23
3
4-Me–C6H4 Ph
4-Cl–C6H4 Ph
4-CN–C6H4 Ph
CH3
CH3
14
13
5
23
Table 1
4
23
Optimization of catalyst for the synthesis of furan-2(5H)-ones from the reaction
between benzaldehyde, aniline and dimethyl acetylenedicarboxylate at room
temperature.
5
CH3CH2 4e
This work
24
6
Ph
Ph
Ph
4-F–C6H4
4-Cl–C6H4
CH3
CH3
4f
4g
4h
4i
9
7
7
24
8
3-NO2–C6H4 CH3
10
9
24
Entry
Catalyst
Time (h)
Isolated yield (%)
9
4-OMe–C6H4 Ph
4-NO2–C6H4 Ph
CH3
CH3
24
1
2
3
4
5
6
7
8
TiO2
15
15
12
12
12
5
25
25
30
50
20
92
26
40
10
11
12
13
14
15
16
4j
2
24
Zn(SO4)2Á7H2O
Zr(NO3)4
ZrCl4
Ph
Ph
Ph
CH3CH2 4k
2
21
4-Me–C6H4 CH3CH2 4l
3
21
4-Me–C6H4 Ph
4-Cl–C6H4 Ph
4-OMe–C6H4 Ph
1-Naphtyl Ph
CH3CH2 4m
CH3CH2 4n
CH3CH2 4o
CH3CH2 4p
4
21
HClO4–SiO2
[Bu4N][HSO4]
KHSO4
4
21
3
21
15
15
10
21
NH4HSO4
a
Yields refer to those of the pure isolated products.
Please cite this article in press as: R. Doostmohammadi, et al., An efficient one-pot multi-component synthesis of 3,4,5-substituted
furan-2(5H)-ones catalyzed by tetra-n-butylammonium bisulfate, Chin. Chem. Lett. (2013), http://dx.doi.org/10.1016/
j.cclet.2013.06.004

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R. Doostmohammadi et al. / Chinese Chemical Letters xxx (2013) xxx–xxx
3
O
H
O
O
H
N
H
N
2
RO
N
Ar
CO R
2
RO
H
N
2
-OR
Ar
1
CO R
2
H
Ar
2
C
C
H
Ar
H
+
2
OR
H
Ar
1
Ar
1
O
O
O
O
H
CO R
2
Ar
CO R
2
Scheme 2. The speculative proposed mechanism for the formation of furan-2(5H)-one derivatives.
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this product, exhibited a triplet at
protons and a quartet for the methylene protons of the carboxylate
group at 4.24 and one sharp singlet arising from the benzylic
5.82. The aromatic protons of the product were
7.17–7.59. A broad singlet for the NH group at 9.03
indicated an intramolecular hydrogen bond formed with the
vicinal carbonyl group. The 13C NMR spectrum of this product
showed 16 distinct resonances in agreement with the proposed
structure. The IR spectrum contained one sharp peak at 3293 cmÀ1
for the NH group in the product.
d 1.23 (J = 7.2 Hz) for the methyl
d
proton at
observed at
d
d
d
A proposed mechanism for the formation of 4 is shown in
Scheme 2.
(b) R. Mabon, A.M.E. Richecoeur, J.B. Sweeney, Preparation and reactions of 3,4-
bis(tributylstannyl)-2(5H)-furanone, J. Org. Chem. 64 (1999) 328–329;
(c) R. Mabon, A.M.E. Richecoeur, J.B. Sweeney, Preparation and reactions of 3,4-
bisstannyl-2(5H)furanones, Tetrahedron 58 (2002) 9117–9129.
4. Conclusion
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Facile and efficient synthesis of 3,4,5-substituted furan-2(5H)-ones by using b-
cyclodextrin as reusable catalyst, Tetrahedron 65 (2009) 5251–5256.
[22] R. Subburethinam, N. Rajagopal, Efficient one-pot multicomponent synthesis of
(carbazolylamino)furan-2(5H)-one and carbazolyltetrahydropyrimidine deriva-
tives, Synthesis 20 (2011) 3307–3317.
In conclusion we have identified an efficient and simple one-pot
reaction for the synthesis of furanone derivatives using tetra-n-
butylammonium bisulfate as an economic catalyst in ethanol. This
methodology has several advantages such as simplified workup
procedures, mild conditions, and the use of green solvents.
[23] L. Nagarapu, U. Nikhil Kumar, P. Upendra, R. Bantu, Simple, convenient method for
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Acknowledgment
We gratefully acknowledge financial support from the Research
Council of the University of Sistan and Baluchestan.
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furan-2(5H)-ones, Res. Chem. Intermed. (2013), http://dx.doi.org/10.1007/
s11164-012-0922-1 (This article is being published).
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Please cite this article in press as: R. Doostmohammadi, et al., An efficient one-pot multi-component synthesis of 3,4,5-substituted
furan-2(5H)-ones catalyzed by tetra-n-butylammonium bisulfate, Chin. Chem. Lett. (2013), http://dx.doi.org/10.1016/
j.cclet.2013.06.004