Kinetics and thermolysis mechanism of some 4-substituted 3-methylfuroxans

Abstract

Thermolysis of the non-condensed furoxans containing two reaction centers for which the initiation of decomposition reaction is possible, has not been adequately studied. We explored kinetics of thermolysis of the furoxans such as: (1–15 wt %) and nature of inert solvent (trinitrobenzene, dibutylphthalate DBP) that is inherent in the homolytic process. Thermolysis of compound II in solution occurs with acceleration and unaffected by the ratio of substance mass to volume of reactionary vessel (m/V = 1.1×10–1.6×10 g cm). It has been established earlier [1] that opening of furoxan ring proceeds at the least strong transannular N(O)–O bond. As a result the low-stable structure forms, stabilizing into the former or isomeric furoxan. At elevated temperatures the furoxan ring opens at N(O)–O and С–С bonds to give the two nitrileoxide functions, which isomerize irreversibly into isocyanate under these conditions [1, 3].