Electrochemical Method for the Preparation of Dibromomethyl, Bis(bromomethyl), and Bis(dibromomethyl) Arenes

Abstract

Electrochemical bromination of alkyl aromatic compounds by two-phase electrolysis yields the corresponding α, α-dibrominated products. The reaction has been carried out in a single-compartment electrochemical cell using aqueous sodium bromide (40–50%), containing a catalytic amount of HBr as electrolyte, and chloroform, containing an alkyl aromatic compound, as the organic phase with a Pt plate as anode at 10–15°C. Two-phase electrolysis results in high yields (70–90%) of dibromomethyl, bis(bromomethyl), and bis(dibromomethyl) arenes, depending upon the charge passed.

Keywords:

• Alkyl aromatic compound
• dibromomethyl arene
• electrochemical bromination
• two-phase electrolysis

Notes

^a Structures were confirmed from their spectra (NMR, IR) data.

^b Isolated yield.

^c p-Nitro bromomethyl benzene (50%) is present along with 50% p-nitro dibromomethyl benzene.

^d Isolated as a solid after trituration with n-hexane.