Thiophanes, aromatization

The thienothienoimidazolium salts 29 were prepared by the reaction of thiophanes 362 with HX (X = halogen) and crystallization from solvents selected from ketones, aromatic hydrocarbons, and halohydrocarbons. l-(—)-3,4-(l, 3 -dibenzyl-2 -ketoimidazolido)-2-(u -ethoxypropyl)tetrahydrothiophene 362 was reacted with HBr at 99-103 °G for 2h and crystallized from methyl-Tro-butyl ketone to give l-(—)-3,4-(T,3 -dibenzyl-2 -ketoimidazolido)-l,2-trimethyle-nethiophanium bromide 29 (95%, 98.7% purity) (Scheme 75) <2001JAK100477>. 

Certain sulfides may be determined by treatment of the naphtha with iodine and measurement of the absorptivity of the resulting complex in the ultraviolet (54). Sulfides 56, 151) are removed with powdered mercurous nitrate monohydrate which readily reacts with aliphatic sulfides and thiophanes but not with thiophenes nor aromatic sulfides (45). 

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