STABLE HETEROARENIUM IONS-IX. DISPROPORTIONATION OF ALKYLTHIOPHENIUM IONS AND ITS USE FOR THE SYNTHESIS OF 2,4-DIALKYLTHIOPHENES

Article abstract of DOI:10.1016/S0040-4020(01)87483-4

A number of isopropyl and ethyl substituted thiophenium ions has been generated by the alkylation of thiophene and protonation of alkylthiophenes.Disproportionation of these ions has been studied at room temperature and at the b.p. of 1,2-dichloroethane used as a solvent while preparing the ions. 2,4-Diethylthiophene has been prepared from its mixture with the 2,5-isomer by disproportionation of the 2,5-diethyl-2H-thiophenium ion.