Urea nitrate catalyzed imino Diels-Alder reactions: Synthesis of cyclopentaquinolines, pyranoquinolines, and furoquinoline derivatives

Article abstract of DOI:10.1081/SCC-120001514

Urea nitrate is found to be an efficient catalyst for the imino Diels-Alder reaction of aldimines with cyclopentadiene, 3,4-dihydropyran and dihydrofuran is reported for the first time. One pot synthesis of cyclopentaquinolines from benzaldehyde, aromatic

Full text of DOI:10.1081/SCC-120001514

This article was downloaded by: [Michigan State University]
On: 25 December 2014, At: 04:17
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer
House, 37-41 Mortimer Street, London W1T 3JH, UK
Synthetic Communications: An International Journal
for Rapid Communication of Synthetic Organic
Chemistry
Publication details, including instructions for authors and subscription information:
http://www.tandfonline.com/loi/lsyc20
UREA NITRATE CATALYZED IMINO DIELS-ALDER
REACTIONS: SYNTHESIS OF CYCLOPENTAQUINOLINES,
PYRANOQUINOLINES, AND FUROQUINOLINE
DERIVATIVES
Marimuthu Anniyappan a , Rajagopal Nagarajan a & Paramasivan T. Perumal
a Organic Chemistry Division, Central Leather Research Institute , Adyar, Chennai, 600
020
Published online: 21 Aug 2006.
To cite this article: Marimuthu Anniyappan , Rajagopal Nagarajan & Paramasivan T. Perumal (2002) UREA NITRATE
CATALYZED IMINO DIELS-ALDER REACTIONS: SYNTHESIS OF CYCLOPENTAQUINOLINES, PYRANOQUINOLINES, AND
FUROQUINOLINE DERIVATIVES, Synthetic Communications: An International Journal for Rapid Communication of Synthetic
Organic Chemistry, 32:1, 99-103, DOI: 10.1081/SCC-120001514
To link to this article: http://dx.doi.org/10.1081/SCC-120001514
PLEASE SCROLL DOWN FOR ARTICLE
Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained
in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no
representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of
the Content. Any opinions and views expressed in this publication are the opinions and views of the authors,
and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied
upon and should be independently verified with primary sources of information. Taylor and Francis shall
not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other
liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or
arising out of the use of the Content.
This article may be used for research, teaching, and private study purposes. Any substantial or systematic
reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any
form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://
www.tandfonline.com/page/terms-and-conditions

SYNTHETIC COMMUNICATIONS, 32(1), 99–103 (2002)
UREA NITRATE CATALYZED IMINO
DIELS-ALDER REACTIONS: SYNTHESIS
OF CYCLOPENTAQUINOLINES,
PYRANOQUINOLINES, AND
FUROQUINOLINE DERIVATIVES
Marimuthu Anniyappan, Rajagopal Nagarajan,
and Paramasivan T. Perumal*
Organic Chemistry Division, Central Leather
Research Institute, Adyar, Chennai-600 020
ABSTRACT
Urea nitrate is found to be an efficient catalyst for the imino
Diels-Alder reaction ofaldimines with cyclopentadiene,
3,4-dihydropyran and dihydrofuran is reported for the first
time. One pot synthesis ofcyclopentaquinolines from benzal-
dehyde, aromatic amines with cyclopentadiene catalyzed by
urea nitrate is also reported.
Pyranoquinoline moiety is present in many alkaloids such as flinder-
sine, oricine and veprisine1 and their derivatives possess wide range ofbio-
logical activities such as psychotropic,2 antiallergenic,3 antiinflammatory4
and estronegic5 activities. Furoquinoline skeleton is present in many alka-
loids like skimmianine and balfouridine.6 Lewis acids like BF3ꢀEt2O,7
*Corresponding author. Fax: 91-044-491 1589; E-mail: ptperumal@hotmail.com
99
Copyright & 2002 by Marcel Dekker, Inc.
www.dekker.com

ORDER
REPRINTS
100
ANNIYAPPAN, NAGARAJAN, AND PERUMAL
10
InCl3,8 lanthanide triflates9 and GdCl3 has been found to catalyze the
reaction ofaldimines with electron rich dienophiles. However, to the best
ofour knowledge there is no report available of r urea nitrate as a catalyst
for the reaction of imines with electron rich alkenes. Since urea nitrate is an
inexpensive, easy to prepare, explored its ability to catalyze the imino
Diels-Alder reactions effectively in shorter reaction times. Recently urea
nitrate was used for the regioselective nitration of 4-halonitrobenzenes to
4-halo-orthodinitro benzene derivatives.11
In the presence of20 mol% urea nitrate, N-benzylidene aniline (1a)
was treated with 3,4-dihydropyran in acetonitrile at room temperature.
After 10 min the pyranoquinolines 3a and 4a obtained in a ratio of33:67
in an overall yield of74% (Scheme 1). The results obtained with other
substituents and with dihydrofuran are given in Table 1.
Scheme 1.
Urea nitrate also catalyzes the reaction ofcyclopentadiene with
N-benzylidene aniline 1a and resulted in the formation of cyclopentaquino-
line 6b in 78% yield (Scheme 2). The results obtained with other substituents
are given in Table 2.
Table 1. Synthesis ofPyrano and Furanoquinolines* Catalyzed by 20 mol% Urea
Nitrate
Schiff
Base
Time
(min)
Product
Ratio 3:4
Overall
Yield (%)
Entry
R
n
1
2
3
1a
1a
1b
H
H
Cl
0
1
1
10
10
10
33:67
33:67
32:68
77
74
78
*Products were characterized by IR, NMR and Mass Spectra.

ORDER
REPRINTS
IMINO DIELS-ALDER REACTIONS
101
Scheme 2.
Table 2. Synthesis ofCyclopentaquinolines Catalyzed by
20 mol% Urea Nitrate
Schiff Base
Substituent R
Time (min)
Yield (%)
1a
1b
1c
1d
H
Cl
COOH
NO2
15
15
15
15
78
71
61
59
The one pot synthesis ofcyclopentaquinolines is also achieved by the
reaction ofbenzaldehyde, substituted aniline with cyclopentadiene catalyzed
by urea nitrate (Scheme 3).
Scheme 3.
In conclusion, this paper describes a simple method for obtaining the
quinoline derivatives using cheaper urea nitrate as a catalyst in shorter
reaction time and also has an advantage that only 20 mol% required for
the cycloadditions.

ORDER
REPRINTS
102
ANNIYAPPAN, NAGARAJAN, AND PERUMAL
EXPERIMENTAL
To a stirred solution ofSchiff base 1b (2.5 mmol) and cyclopentadiene
(0.330 g, 5 mmol) in acetonitrile (10 mL) was added urea nitrate (0.093,
20 mol%) and stirred at room temperature for 15 min. The reaction mixture
poured over ice water and extracted with chloroform (3 ꢁ 10 mL). The com-
bined organic layer was washed with saturated NaHCO3 (10 mL) and brine
(10 mL), dried over anhydrous Na2SO4, then concentrated under reduced
pressure. The residue was purified by column chromatography using silica-
gel (60–120 mesh) and eluted with petroleum ether:ethyl acetate (95:5) to
afford 3b as pale yellow crystalline solid in 71% yield.
1H NMR (300 MHz, CDCl3): d 7.44 (m, 5H), 7.04 (d, 1H, J ¼ 2.1 Hz),
6.93 (dd, 1H, J ¼ 2.2 Hz, J ¼ 8.6 Hz), 6.55 (d, 1H, J ¼ 8.5 Hz), 5.82 (m, 1H),
5.69 (m, 1H), 4.61 (d, 2H, J ¼ 2.9 Hz), 4.09 (d, 1H, J ¼ 8.6 Hz), 3.76 (br s,
1H), 3.05 (m, 1H), 2.67 (m, 1H), 1.86 (m, 1H); 13C NMR (75 MHz, CDCl3):
d 144.1, 142.3, 133.4, 130.8, 128.6, 128.4, 127.6, 127.3, 126.4, 123.4, 116.9,
57.9, 46.2, 45.7, 31.4; MS (m/z); 281 (Mþ), 283 (M þ 2); IR (KBr): 3363,
1470 cmꢂ1
.
ACKNOWLEDGMENT
We thank Council ofScientific and Industrial Research, New Delhi,
India for financial support.
REFERENCES
1. Ramesh, M.; Mohan, P.A.; Shanmugam, P. Tetrahedron 1984, 40, 4041.
2. Nesterova, I.N.; Alekseeva, L.M.; Andreeva, L.M.; Andreeva, N.I.;
Golovira, S.M.; Granik, V.G. Khim.-Farm. Zh. 1995, 29, 31. (Russ);
Chem. Abstr. 1996, 128, 117128t.
3. Yamada, N.; Kadowaki, S.; Takahashi, K.; Umezu, K. Biochem.
Pharmacol. 1992, 44, 1211.
4. Faber, K.; Stueckler, H.; Kappe, T. J. Heterocycl. Chem. 1984, 21, 1177.
5. Akhmed Khodzhaeva, K.S.; Bessonova, I.A. Dokl. Akad. Nauk Uzh.
SSR 1982, 34. (Russ); Chem. Abstr. 1983, 98, 83727q. (a) Jurd, L.;
Wong, R.V. Aust. J. Chem. 1981, 34, 1625. (b) Coppola, G.M.
J. Heterocycl. Chem. 1983, 20, 1217.
6. Kametani, T.; Takeda, H.; Suzuki, Y.; Honda, T. Synth. Commun.
1985, 15, 499.
7. Babu, G.; Perumal, P.T. Tetrahedron Lett. 1997, 38, 5025.

ORDER
REPRINTS
IMINO DIELS-ALDER REACTIONS
103
8. Kobayashi, S.; Ishitani, H.; Nagayama, S. Synthesis 1995, 1195.
9. Ma, Y.; Qian, C.; Xie, M.; Sun, J. J. Org. Chem. 1999, 64, 6462.
10. Mundla, S.R. Tetrahedron Lett. 2000, 41, 4277.
Received in the Netherlands February 28, 2001

Request Permission or Order Reprints Instantly!
Interested in copying and sharing this article? In most cases, U.S. Copyright
Law requires that you get permission from the article’s rightsholder before
using copyrighted content.
All information and materials found in this article, including but not limited
to text, trademarks, patents, logos, graphics and images (the "Materials"), are
the copyrighted works and other forms of intellectual property of Marcel
Dekker, Inc., or its licensors. All rights not expressly granted are reserved.
Get permission to lawfully reproduce and distribute the Materials or order
reprints quickly and painlessly. Simply click on the "Request
Permission/Reprints Here" link below and follow the instructions. Visit the
U.S. Copyright Office for information on Fair Use limitations of U.S.
copyright law. Please refer to The Association of American Publishers’
(AAP) website for guidelines on Fair Use in the Classroom.
The Materials are for your personal use only and cannot be reformatted,
reposted, resold or distributed by electronic means or otherwise without
permission from Marcel Dekker, Inc. Marcel Dekker, Inc. grants you the
limited right to display the Materials only on your personal computer or
personal wireless device, and to copy and download single copies of such
Materials provided that any copyright, trademark or other notice appearing
on such Materials is also retained by, displayed, copied or downloaded as
part of the Materials and is not removed or obscured, and provided you do
not edit, modify, alter or enhance the Materials. Please refer to our Website
User Agreement for more details.
Order now!
Reprints of this article can also be ordered at
http://www.dekker.com/servlet/product/DOI/101081SCC120001514