1-Oxoisoindole cations

Abstract

The preparation and properties of 3-t-butyl-, 3-phenyl-, 2-methyl-3-phenyl-, 2-ethyl-3-phenyl-, and 2,3-diphenyl-1-oxoisoindolium hexachloroantimonates, obtained from the respective 3-chloro-2,3-dihydro-1-oxoisoindoles and antimony pentachloride, are described. These 1-oxoisoindole cations were also formed when the corresponding 2,3-dihydro-3-hydroxy-1-oxoisoindoles were dissolved in concentrated sulphuric acid. 2,3-Dihydro-3-hydroxy-1-oxoisoindole, when treated with thionyl chloride, gave a cyclic 1-oxoisoindole trimer, and 3,3′-diphenyl-1,1′-bi-isoindolylidene was obtained from 2,3-dihydro-3-phenyl-1-oxoisoindole and the same reagent.