A comparative study on the reactivity of electrogenerated bromine with cyclohexene in acetonitrile and the room temperature ionic liquid, 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide

The reactivity of electrogenerated bromine with cyclohexene has been studied on a platinum microelectrode by linear sweep and cyclic voltammetry in both the room temperature ionic liquid, 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide, and the conventional aprotic solvent, acetonitrile. Variation in the voltammetric response was observed in the two solvents, indicating that the bromination reaction proceeded via separate mechanisms. To identify the different products, electrolysis was conducted on the preparative scale and NMR spectroscopy confirmed that while bromination of the organic substrate in the ionic liquid yields trans-1,2-dibromocyclohexane, in acetonitrile, trans-1-(N-acetylamino)-2-bromocyclohexane is instead obtained as the major product. The reaction mechanism for bromination in acetonitrile has been modeled using digital simulation.