N. Iranpoor et al. / Tetrahedron Letters 47 (2006) 6879–6881
6881
Table 3. Selective nitration of N-methylaniline with Ph3P/Br2/AgNO3
in different binary mixtures in acetonitrile at room temperaturea
Acknowledgements
We are thankful to the Organization of Management
and planning, Iran, and the Shiraz University Research
Council for the support of this work.
Entry
1
Binary mixture
Time (min)
5
Conversionb (%)
N-Methylaniline
Anisole
100
0
2
3
4
N-Methylaniline
Naphthalene
N-Methylaniline
Anthracene
N-Methylaniline
Acetanilide
5
5
5
100
0
100
0
100
0
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1
152 ꢁC)]; H NMR (CDCl3): d (ppm) = 2.8 (3H, s), 4.7
(1H, s), 6.5 (2H, m, AA0XX0), 8.1 (2H, m, AA0XX0);
13C NMR (CDCl3): d (ppm) = 30.25, 110.52, 126.40,
138.0, 154.44 and N-methyl-2-nitroaniline [Reg. No.
612-28-2, (mp 36–37 ꢁC, lit.24 35–38 ꢁC)]; 1H NMR
(CDCl3): d (ppm) = 3.0 (3H, s), 6.65–8.15 (4H, m), 8.0
(1H, s, br); 13C NMR (CDCl3): d (ppm) = 29.54,
113.0, 115.22, 126.65, 132.0, 136.33, 146.40 in 78% and
15% yields, respectively.
In conclusion, the present investigation has demon-
strated the use of the Ph3P/Br2/AgNO3 system as a very
simple mixed reagent system for the efficient nitration of
aromatic amines in high yields and short reaction times.
In addition, the method shows excellent chemoselectiv-
ity for the nitration of aromatic amines.