The pyrolysis of polycarbonyl compounds. I. Mass spectral and pyrolytic fragmentation of indanetrione

Abstract

Pyrolysis of indanetrione at 500-800� produces benzyne, which was detected by its reaction with benzene and with chlorobenzene and, in pyrolyses in vacuo, by the formation of biphenylene and triphenylene. The isolation of the carbonyl compounds benzocyclobutenedione, fluorenone, anthraquinone, and phenanthrene-quinone from some pyrolyses suggests that loss of carbon monoxide occurs in successive steps which parallel those in the mass spectral fragmentation of the indanetrione molecular ion. A species having the composition of benzocyclopropenone (X) may be involved in the formation of fluorenone, anthraquinone, and phenanthrenequinone.