Chemistry Letters 2000
49
In order to shed light on the reaction mechanism, the
kinetic work is under investigation to prove the exact path of
the reaction and the formation of intermediate. However, it is
believed that nitration is taking place via the formation of nitro-
nium ion bound molybdenum species. It is also believed that
the mechanism is similar to that of the literature reports.11 The
reaction with 0.25 equivalent or 0.5 equivalent of ammonium
molybdate is very slow. Therefore, reaction is carried out at
1:1:1 molar ratio. The nitrated products were characterized by
5
6
(a) B. M. Trost, and M. Lautens, J. Am. Chem. Soc., 104,
5543 (1982); (b) B. M. Trost, and M. Lautens, J. Am.
Chem. Soc., 105, 3343 (1983); (c) B. M. Trost, and M.
Lautens, Tetrahedron Lett., 24, 4525 (1983); (d) B. M.
Trost, J. I. Yoshida, and M. Lautens, J. Am. Chem. Soc.,
105, 4494 (1983).
(a) H. Mimoun, in "The Chemistry of Functional Group
Peroxides," ed by S. Patai, Wiley, New York, (1982),
p.463; (b) H. Mimoun, Pure Appl. Chem., 53, 2389
(1981); (c) R. A. Sheldon and J. K. Kochi, in "Metal
Catalyzed Oxidations of Organic Compounds," Academic
Press, New York (1981), p.48; (d) K. B. Sharpless, and T.
R. Verhoeven, Aldrichimia Acta, 12, 63074 (1979).
(a) S. E. Jacobsen, D. A. Miccigrosso, and F. Mores, J.
Org. Chem., 44, 921 (1979); (b) H. Tomioka, K. Takai, K.
Oshima, H. Nozaki, and K. Toriumi, Tetrahedron Lett.,
21, 4843 (1980).
1
comparison of their spectral (IR, UV, H-NMR, HPLC and
TLC) and physical data with authentic samples.
The results clearly indicate that the direct nitration of
anilides, non-activated and moderately activated aromatic com-
pounds can be achieved successfully by employing ammonium
molybdate and nitric acid as nitrating agent.
In conclusion, the present method of nitration of anilides,
non-activated and moderately activated aromatic compounds
using ammonium molybdate as catalyst with high regioselec-
tivity offers the advantages such as, environmentally safe, read-
ily available inexpensive reagents and mild reaction conditions
with simple work up. Thus, it is believed that the present
method is to be a major step forwarded in the area of clean
technology for aromatic nitration.
7
8
9
(a) B. M. Choudary, Y. Sudha, and P. N. Reddy, Syn. Lett.,
(1994), 450; (b) B. M. Trost, and Y. Mosuyama,
Tetrahedron Lett., 25, 173 (1984).
E. M. Nahmed, and G. Jenner, Tetrahedron Lett., 32, 4917
(1991).
10 S. Sana, M. M. Ali, K. C. Rajanna, and P. K. Saiprakash,
Submitted to Synth. Commun.
References and Notes
11 (a) H. Soto, K. Nagai, H. Yoshioka, and Y. Nagaoka,
Appl. Cat. A, 175, 209 (1998); (b) H. Sato, K. Hirose, K.
Nagai, H. Yoshioka, and Y. Nagaoka, App. Cat. A., 175,
201 (1998).
12 Nitration of Anilides: Dissolve the anilide (1 mmol) in
CHCl3 and add ammonium molybdate (1.235 gms, 1
mmol), 70% HNO3 (0.063 ml, 1 mmol) and reflux for 6 hr.
Check the TLC for completion of the reaction. Filter the
reaction mixture, wash it with water, separate the organic
layer, then dry it over with sodium sulphate (Na2SO4),
evaporate under vacuum, purify with column chromatog-
raphy using chloroform : methanol (9.9 : 0.1) as eluent to
get pure product.
1
V. Snieckus, Chem. Rev., 90, 879 (1990).
2
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3
4
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