New stable nitroxyl radicals from hydrogenated quinolines

Syntheses were reported for 6-triphenylmethyl derivatives of 2,2,4-trimethyl-1,2-dihydroquinolines and 2,2,4-trimethyl-1,2,3,4-tetrahydroquinolines as well as 4-phenpl-1,2,3,4-tetrahydroquinoline. The oxidation of these compounds by H2O2 in the presence of Na2WO4 and also by m-chloroperbenzoic acid gave nitroxyl radicals, whose structures were supported by EPR spectroscopy.