B. H. Kim et al. / Tetrahedron Letters 44 (2003) 77–79
79
in the presence of Ac2O in aqueous ethanol containing
ammonium chloride (Moody’s indium-mediated reduc-
tive condition)9 gave N-phenylacetamide in relatively
low yield, along with aniline, N,O-diacylated N-phenyl-
hydroxylamine, and azobenzene (Table 1, entry 1). The
reaction of nitrobenzene using Ac2O–In in MeOH also
did not proceed well also, as expected (Table 1, entry
2). However, the addition of AcOH to the reaction
mixture gave better results. Although the reactions of
nitrobenzene (1a) using Ac2O–AcOH–In in THF sol-
vent or THF–MeOH co-solvent gave the desired N-
phenylacetamide (3a) in low yield (Table 1, entries 3
and 4), the reactions in MeOH solution with suitable
amounts of Ac2O–AcOH–In were drastically improved
(Table 1, entries 5–7). The best results were obtained
with nitrobenzene/Ac2O (2.5 equiv.)/AcOH (10 equiv.)/
In (5 equiv.) in MeOH at room temperature (Table 1,
entry 6).
through a silica gel column to give the corresponding
N-arylacetamide (3).
In conclusion, we have described a simple and efficient
method for the one-pot preparation of N-arylacet-
amides from nitroarenes using Ac2O–AcOH–In in
MeOH under mild conditions.
Acknowledgements
This work was supported by the Brain Korea 21 Project
and partly by Kwangwoon University in the year 2002.
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Typical procedure for the reductive acylation: Acetic
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