A. K. Bose et al. / Tetrahedron Letters 45 (2004) 1179–1181
1181
natural product and its analogues and derivatives will
now be undertaken.
not needed. For a recent review on ÔMORE chemistry for
less polutionÕ, see Bose, A. K.; Manhas, M. S.; Ganguly,
S. N.; Sharma, A. H.; Banik, B. K. Synthesis 2002, 1578–
1
2
591; (b) This paper is MORE chemistry Part 21; for part
0, see Pramanik, B. N.; Ing, Y. H.; Bose, A. K.; Zhang,
L.-K.; Liu, Y.-H.; Ganguly, S. N.; Bartner, P. Tetrahedron
Lett. 2003, 44, 2565–2568.
Acknowledgements
9
. Bose, Ajay K.; Manhas, M. S.; Ganguly, S. N.; Srirajan,
V.; Lavlinskaia, N.; Bari, S. S.; Lavlinski, D. ÔMicrowave
Assisted Aromatic Nitration: Eco-friendly Rapid Pro-
cessesÕ, Presented at the 215th ACS National Meeting,
Dallas, TX, 1998, ORGN 233.
We are grateful to Stevens Institute of Technology for
research facilities and to the George Barasch Research
Fellowship Fund for partial financial support. We wish
to thank Nina Lavlinskaia and Dmitri Lavlinski for
technical assistance.
1
0. Gigante, B.; Prazeres, A. O.; Marcelo-Curto, M. J.;
Cornelis, A.; Laszlo, P. J. Org. Chem. 1995, 60, 3445.
1. Nitration of 4-hydroxybenzaldehyde: 4-Hydroxybenzalde-
hyde (2 g) mixed with 15 mL of 10% aqueous nitric acid
was irradiated in a domestic microwave oven for 1 min at
power level 500 W. The final temperature of the reaction
mixture was 85 °C. An examination of the reaction
mixture by thin layer chromatography showed the disap-
pearance of the starting material. The reaction mixture
was cooled to room temperature and 70 mL of cold water
was added to it when a light orange colored solid
separated. This solid was filtered, washed with water till
free from acid, dried and then recrystallized from a
benzene-methanol mixture, mp 141–142 °C. This com-
pound, obtained in 85% yield, was found to be identical
with an authentic sample of 3-nitro-4-hydroxy benzalde-
hyde.
1
References and notes
1
. This project was jointly sponsored by the Department of
Science and Technology (DST) of the Government of
India and the Oceanic Biology Program of the Office of
Naval Research (ONR) of the United States Government.
Funding for this project was under the authority of US
Public Law 480 that supported in part research of
international importance to be conducted in a foreign
nation (India) where an excess of US currency existed.
. Samples were collected from mangrove plants growing in
brackish waters subject to rise and fall in salinity with the
ebb and flow of the tide. During the monsoon season the
salinity of the water was reduced due to the heavy influx of
fresh water from rivers and rivulets. This change in salinity
may constitute stress on the mangrove plant.
2
3
12. Nitration of 4-hydroxycinnamic acid: A mixture of 1 g of
4-hydroxycinnamic acid and 10 mL of 15% aq. nitric acid
was placed in a 100 mL conical flask. This flask with a
funnel as the top was placed in an unmodified domestic
microwave oven. Microwave irradiation was conducted at
400 W level for 1 min. The bulk temperature of the
reaction was found to be about 60 °C. An examination
of the reaction mixture by thin layer chromatography
showed the disappearance of almost all of the starting
material. After cooling the reaction mixture to room
temperature 60 mL of cold water was added to it. The
orange yellow solid that separated was collected by
filtration, washed free of acid with cold water, dried and
then recrystallized from methanol–benzene, mp 146 °C.
The yield of the desired dinitro compound 1 was 80%.
. In an earlier study leaves of the mangrove plant were
found to contain plant-growth regulators, gibberellins,
cytokinin, and zeatin: Ray, M.; Ganguly, S. N. Plant
Physiol. Biochem. 1988, 15, 248.
4
5
6
. Urbanczyk-Lipkowska, Z.; Lee, M. Y. Polish J. Chem.
1
992, 66, 1805.
. Chibu, M.; Abiko, M.; Kawamura, Y. Japan Patent 3902
960, 1964.
. Hanawa, F.; Tahara, S.; Towers, G. H. N. Phytochemistry
000, 53, 55–58.
6
2
7
8
. Ina, H.; Iida, H. Chem. Pharm. Bull. 1986, 34, 726.
. (a) MORE chemistry techniques were devised to avoid
possibility of explosion reported by earlier workers in
some cases when reactions were conducted in sealed
systems under microwave irradiation. The strategy behind
MORE chemistry is to use open vessels with reactants in a
shallow layer (no stirring needed in most cases), with
minimal quantities of a higher boiling solvent (or no
solvent if one or more reactants are liquid). The micro-
wave energy input is controlled to reach an appropiate
bulk temperature of the reaction mixture with minimal
vaporization (by maintaining the reaction mixture about
5
13. Japanese workers had recorded the mp of 1 as 152 °C. We
have observed that the mp of different batches of 1 varies
from 146–152 °C depending on the solvent and the mode
of crystallization. This is not surprising because X-ray
diffraction studies have shown that there are two poly-
morphic forms of 1, which differ from each other in color,
hydrogen bonding pattern, crystal lattice construction,
4
and melting point. The samples prepared in our labora-
tory were shown to have the correct structure by studying
1
their H NMR spectra in CDCl
spectra.
3
solution and their mass
20 °C below the boiling point of reactants). Reflux
condensers and flasks with ground glass joints thus are
14. Monomodal microwave applicators are now available
from the CEM Corporation.