The Reactivity of Peroxyl RadicalsToward 5-Methyl-4-[(Propylsulphanyl)Methyl]-2,4-Dihydro-3<i>H</i>-Pyrazole-3-One
5-Methyl-4-[(propylsulfanyl)methyl]-2,4-dihydro-3<i>H</i>-pyrazole-3-one inhibits peroxidation of 1,4-dioxane, ethylbenzene and methyl oleate, was shown. One peroxyl radical is trapped by each molecule (propylsulfanylmethyl)-substituted 2,4-dihydro-3<i>H</i>-pyrazol-3-one, was found. The reaction rate constant of the studied compound with a peroxyl radical depends on the structure of the latter and decreases in the row: the peroxyl radical of 1,4-dioxane, ethylbenzene, and methyl oleate (<i>k</i><sub>7</sub> × 10<sup>4</sup>, l mol<sup>–1</sup> s<sup>–1</sup>, 333 K: 5.7, 4.1, 1.1). The reason for the observed dependence is discussed.