Synthesis and Characterization of Phenyl-Substituted C-Phenyl-N-tert-butylnitrones and Some of Their Radical Adducts

Article abstract of DOI:10.1021/jo00035a020

Synthesis of C-phenyl-N-tert-butylnitrone (PBN) and several of its analogues with substituents in the 2-, 3-, or 4-position on the phenyl ring is described.While a one-pot reduction/condensation method proved suitable for the most compounds, it was necessary to prepare some examples by direct condensation or through oxidation of the appropriate imine.The 1H NMR data for the 3-X- and 4-X-PBN's can be correlated with the Hammett equation.For the 3-X series Δδ for the α-proton correlates best with ?⁺ and has a correlation coefficient of 0.90.For the 4-X series a dual substituent parameter equation using ?_R⁰ gives the best correlation with r = 0.99.The hyperfine splitting constants (hfsc's) of HO<*> and HOO<*> adducts of serveral substituted PBN's are also included and their correlation with the Hammett equation is discussed.