Synthesis and EPR spin trapping properties of a new isoindole-based nitrone: 1,1,3-trimethylisoindole N-oxide (TMINO)

Here we describe the synthesis and characterisation of a new isoindole-based nitrone spin trap, 1,1,3-trimethylisoindole N-oxide (TMINO). This nitrone and its radical adducts (isoindoline nitroxides) exhibit enhanced stability with respect to other commonly used spin traps and their adducts. We also report EPR trapping studies of this new nitrone with some carbon- and oxygen-centred radicals including alkyl, aryl, hydroxyl and benzoyloxyl systems. The narrow EPR line-widths and stability of the resulting nitroxide spin adducts allowed the detection of the expected radicals as well as secondary and minor radical components in the reaction mixtures.