Preparation, Characterization, and Flash Vacuum Pyrolysis of Dibenz[c,e][l,2]oxathiin 6-Oxide (Biphenylene Sultine)

Abstract

Dibenz[c,e][l,2]oxathiin 6-oxide (2), previously proposed as an intermediate in the pyrolysis of dibenzothiophene 5,5-dioxide (1), has been prepared by the treatment of 1 with KOH in the presence of crown ether followed by an acid workup. The likely intermediacy of the dipotassium salt of 2-(2-hydroxyphenyl)benzenesulfmic acid is demonstrated. Flash pyrolysis of 2 gives dibenzofuran and dibenzothiophene in essentially the same ratio as when they are formed in the pyrolysis of 1, suggesting that both products arise from the intermediacy of 2. © 1981, American Chemical Society. All rights reserved.