Selective desulfurization of benzothiophene derivatives using hydrogen storage alloys

Hydrodesulfurization of a series of benzothiophene derivatives using hydrogen storage alloys as stoichiometric reagents, typically LaNi5, was investigated. It was found that the reactions of benzothiophene and dibenzothiophene with the pre-hydrogenated alloys in nitrogen selectively produced ethylbenzene and biphenyl, respectively, along with extremely minor amounts of aromatic ring-hydrogenated compounds in appropriate conditions. Even with a sterically hindered compound, 4,6-dimethyldibenzothiophene, hydrogenation of which, using conventional Co-Mo or Ni-Mo catalysts, tends to produce ring-saturated products, 3,3'-dimethylbiphenyl, was obtained as the predominant product. The alloys, thus, appear to be useful reagents for selective of elimination sulfur from sulfur-containing aromatic compounds.