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OXYBROMINATION OF AROMATICS
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OxoneÕ, in direct comparison, has a higher onset of decomposition
than hydrogen peroxide and liberates less energy. This reaction is performed
at lower temperature, which provides a larger margin of safety. Additionally
oxoneÕ is a solid, allowing for the addition of precisely weighed amounts
of reagent to be used in the reaction.
In conclusion, we have developed a practical method using oxoneÕ
as an interesting alternative to hydrogen peroxide in the oxidative bromina-
tion of aromatic compounds. The commercial availability of the reagent,
simple reaction conditions, no evaluation of hydrogen bromide and
excellent yields of monobrominated products make our method valuable
from a preparative point of view.
General Procedure for the Bromination of Aromatic Compounds:
OxoneÕ (2.2 mmol) was added to a well stirred solution of KBr
(2.2 mmol) and substrate (2.0 mmol) in methanol (10 mL) and the reaction
mixture was allowed to stir at room temperature. The reaction was
monitored by thin layer chromatography (TLC). After the completion of
the reaction. The mixture was filtered and solvent evaporated under reduced
pressure. The products were purified by column chromatography over silica
1
gel and confirmed by H NMR and Mass spectra.
ACKNOWLEDGMENTS
We are thankful to Department of Science and Technology, New Delhi
for funding, DST Project No.: SP/S1/H07/97.
REFERENCES
1. Ulmann’s Encyclopedia of Industrial Chemistry, 6th Ed.; Electronic
Release, Wiley-VCH: Weinheim, 1998.
2. Schmid, H. Helv. Chim. Acta 1946, 29, 1144.
3. Lambert, F.L.; Ellis, W.D.; Parry, R.J. J. Org. Chem. 1965, 30, 304.
4. Konishi, H.; Aritomi, K.; Okano, T.; Kiji, J. Bull. Chem. Soc., Jpn.
1989, 62, 591.
5. Bovonsombat, P.; McNelis, E. Synthesis 1993, 237.
6. Smith, K.; Bahzad, D. J. Chem. Soc. Chem. Commun. 1996, 467.
7. Paul, V.; Sudalai, A.; Daniel, T.; Srinivasan, K.V. Tetrahedron Lett.
1994, 35, 7055.
8. Choudary, B.M.; Sudha, Y.; Reddy, P.N. Synlett. 1994, 450.
9. Auerbach, J.; Weissman, S.A.; Blacklock, T.J.; Angelss, M.R.;
Hoogsteen, K. Tetrahedron Lett. 1993, 34, 931.