Nitroxide chemistry. Part VII. Synthesis and some reactions of perfluoro-2,5-diazahexane 2,5-dioxyl

Abstract

Oxidation by potassium permanganate of aqueous perfluoro-2,5-diazahexane-2,5-diol obtained by hydrolysis of a trifluoronitrosomethane–tetrafluoroethylene–phosphorus trichloride 2 : 1 : 1 adduct yields perfluoro-2,5-diazahexane 2,5-dioxyl. The dioxyl reacts with hydrogen bromide to give the parent diol, with nitric oxide to yield perfluoro-2,5-dinitro-2,5-diazahexane, with tetrafluoroethylene to provide perfluoro-(2,5-dimethyl-1,6-dioxa-2,5-diazacyclo-octane) and an alternating copolymer, –[O·N(CF3)·CF2CF2·N(CF3)·O·CF2CF2]–n, with perfluoropropene to afford perfluoro-(2,5,7-trimethyl-1,6-dioxa-2,5-diazacyclo-octane) and a copolymer, and with trifluoronitrosomethane or perfluoro-1-nitrosopropane to yield perfluoro-(2,5-dimethyl-1-oxa-2,5-diazacyclopentane). The last product rapidly oxidises iodide ion to iodine and decomposes slowly at room temperature into perfluoro-(N-methylenemethylamine) and perfluoropoly-[(N-methylenemethylamine)N-oxide); decomposition in the presence of hydrogen fluoride gives bistrifluoromethylamine and NN-bistrifluoromethylhydroxylamine. Flow pyrolysis of the diazacyclopentane at 155 °C and ca. 1 mmHg pressure yields a complex mixture believed to contain perfluoro-(N-methylenemethylamine)N-oxide.A laboratory apparatus for the continuous production of trifluoronitrosomethane via pyrolysis of trifluoroacetyl nitrite is described.