The benzofuranone dimers 9 and 10/11 readily (ca. 75°C) dissociate to the persistent radicals 16 and 17 respectively, which are stable to, dioxygen. The OMe analog 25 dissociates to form the radical 24, which reacts with dioxygen of TEMPO to give 26. © 2004 Published by Elsevier Ltd.
Magnus, P., Venable, J. D., Shen, L., & Lynch, V. (2005). Some reactions of persistent benzofuranone radicals related to the “old” diazonamide structure. Tetrahedron Letters, 46(4), 707–710. https://doi.org/10.1016/j.tetlet.2004.11.103