Mild, Efficient, and Regioselective Monobromination of Arylamines and Phenols Using [BBIm]Br₃ as a New Reagent

Abstract

We report here an efficient method for the synthesis and characterization of the room-temperature ionic liquid 1,3-di-n-butylimidazolium tribromide ([BBIm]Br₃) (2) and its application as an efficient reagent and solvent for regioselective bromination of arylamines and phenols under mild conditions. The bromination was carried out in the absence of organic solvents, and in most cases, the only extraction solvent needed was water. The spent 1,3-di-n-butylimidazolium bromide (1) was easily recycled.

Keywords:

• [BBIm]Br₃
• ionic liquid
• monobromination
• regioselective
• solvent-free

ACKNOWLEDGMENTS

This work was carried out under Indo-Mexican Inter-Governmental joint project (GAP 264126) and is greatly acknowledged. We are grateful to Dr. Ganesh Pandey for his support and encouragement.

Notes

^a All reactions were carried out with 1.0 equivalent of [BBIm]Br₃ at room temperature.

^b All compounds showed satisfactory ¹H NMR and spectral data.