抄録
The anodic oxidation of 4-diethylaminoantipyrine (I) has been investigated in acetonitrile at a glassy-carbon electrode. The first step in the anodic oxidation of I is a quasireversible one-electron transfer to form the blue-violet cation radical (II) just as that of 4-dimethylaminoantipyrine (DMA). However, the lifetime of II is much longer than that of the cation radical of DMA (DMA·+). A slightly resolved ESR spectrum of II was obtained. In the absence of oxygen II decays in a first-order manner up to 50% decay, whereas in the presence of oxygen II decays in a second-order manner up to 60% decay. The difference in the behaviors between II and DMA·+ is interpreted on the basis of a much less reactivity of II towards disproportionation than that of DMA·+. A mechanism for the disappearance of II in the absence of oxygen is suggested.
