Substituted Dibenzothiophenes II: Synthesis, Chromatography, Mass Spectrometry and Structure Elucidation by ¹H NMR Spectroscopy of 3-Monochloro-, 1,3-Dichloro-, 1,3,4-Trichloro- and Some Other Substituted Dibenzothiophenes

Abstract

As a continuation of earlier research some more polychlorinated and polymethylated dibenzothiophenes (PCDBTs and PMetDBTs, respectively) have been synthesized and separated. The synthesis mixtures have been fractionated by reversed-phase HPLC to obtain pure isomers. The influence of reaction time and reaction temperature on the production of the isomers has been studied. The reaction temperature was found to have a major influence on the isomer pattern obtained in the product mixture. The structures of the pure fractions were studied by GC-MS and ¹H NMR. Formation of 3-monochloro-, 1,3-dichloro- and 1,3,4-trichlorodibenzothiophene can be ascertained by computer based ¹H NMR spectral analysis. In addition, structures for several tri-and tetra-Met/CDBTs can be given based on the ¹H NMR results.

Key Words:

• Methylated dibenzothiophenes
• chlorinated dibenzothiophenes
• reversed-phase HPLC
• mass spectrometry
• ¹H NMR spectroscopy