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The tetraalkylation of N-benzylphthalimide is the major yield limiting step in the common synthetic route to isoindoline nitroxides. The progress of this reaction was found to be limited by the formation of previously unobserved mono- and dialkyl side products that do not lead to the desired product. The yield for the tetraalkylation of N-benzylphthalimide with ethylmagnesium iodide could be increased (60 % over two steps) when a stepwise addition sequence was employed. The new two-step synthesis offers a practical preparative scale alternative to the current approach.

This paper presents a review on the use of tethered nitroxide–fluorophore molecules as probes of oxidative change and free radical generation and reaction. The proximity of the nitroxide free radical to the fluorophore suppresses the normal fluorescence emission process. Nitroxide free radical scavenging, metabolism or redox chemistry return the system to its natural fluorescent state and so these tethered nitroxide–fluorophore molecules are described as being profluorescent. A survey of profluorescent nitroxides found in the literature is provided as well as background on the mechanism of action and applications of these compounds as fluorometric probes within the fields of biological, materials and environmental sciences.

A novel nitroxide‐mediated polymerization (NMP) control agent; 1,1,3,3‐tetramethyl‐2,3‐dihydro‐2‐azaphenalen‐2‐yloxyl (TMAO), was used in the free‐radical polymerization of styrene. The conversion of styrene during NMP was studied using FT‐Raman spectroscopy and the effectiveness of TMAO as a NMP control agent was assessed by GPC analysis. Fidelity of the TMAO‐alkoxyamine end‐group on the synthesized polymers was confirmed by GPC, UV‐Vis and fluorescence spectroscopic analyses. Comparison to the well known NMP control agent, TEMPO was made. TMAO showed control of molecular weight approaching that of TEMPO. Attempts to improve the properties of TMAO as an NMP control agent by synthesizing an analogue with bulkier substituents around the nitroxide did not generate the target molecule but demonstrated some of the interesting chemistry of the azaphenalene ring system.

A novel nitroxide-mediated polymerization (NMP) control agent; 1,1,3,3-tetramethyl-2,3-dihydro-2-azaphenalen-2-yloxyl (TMAO), was used in the free-radical polymerization of styrene. The conversion of styrene during NMP was studied using FT-Raman spectroscopy and the effectiveness of TMAO as a NMP control agent was assessed by GPC analysis. Fidelity of the TMAO-alkoxyamine end-group on the synthesized polymers was confirmed by GPC, UV-Vis and fluorescence spectroscopic analyses. Comparison to the well known NMP control agent, TEMPO was made. TMAO showed control of molecular weight approaching that of TEMPO. Attempts to improve the properties of TMAO as an NMP control agent by synthesizing an analogue with bulkier substituents around the nitroxide did not generate the target molecule but demonstrated some of the interesting chemistry of the azaphenalene ring system.

1,1,3,3-Tetraalkylisoindolines are important intermediates in the preparation of stable nitroxides, such as 1,1,3,3-tetramethylisoindolin-2-oxyl, 1, and 1,1,3,3-tetraethylisoindolin-2-oxyl, 2. The limiting step in their preparation is the Grignard reaction between N-benzylphthalimide and the appropriate alkyl magnesium bromide, which typically proceeds in yields of ~28–40%. A microwave-assisted variation of this reaction has been optimized to give improved yields and reduced reaction times (45–60% and 2 h, respectively).