Efficient, Rapid, and Regioselective Bromination of Phenols and Anilines with N-Bromosaccharin Using Tungstophosphoric Acid as a Heterogeneous Recyclable Catalyst

Abstract

A simple, efficient, and rapid method for high-yielding regioselective mono bromination of phenols and anilines has been achieved by treatment with N-bromasaccharin in the presence of a catalytic amount of tungstophosphoric acid.

Keywords:

• Anilines
• bromination
• N-bromosaccharin
• phenols
• tungstophosphoric acid

ACKNOWLEDGMENT

Financial support of this work from the Research Council of Mazandran University is gratefully acknowledged.

Notes

^a The conversions of all reactions were 100%.

^a The molar ratios of phenol and aniline derivatives to NBSac was 1:1, except for entries 7–10 and 14–17, which were 1:2.

^b All products were characterized spectroscopically (¹H NMR, IR) and showed physical and spectral data in accordance with their expected structure and by comparison with authentic samples.

^c Yields refer to isolated pure products.