STABLE HETEROARENIUM IONS - VIII SOME TRANSFORMATIONS OF ALKYLTHIOPHENIUM IONS AND NEW SYNTHESIS OF 2-t-BUTYLTHIOPHENE

Article abstract of DOI:10.1016/S0040-4020(01)83499-2

The ratio of isomeric ?-complexes formed from thiophene, t-butyl chloride and AlCl3 was found to be changed while keeping at room temperature whitin 1-2 days.This allows to obtain after deprotonation 2-t-butylthiophene containing only 3percent of 3-isomer.Transformations of ?-complexes formed by protonation of individual 2- and 3-t-butylthiophenes in the presence of AlCl3 have been studied and there was found that isomerization and deprotonation took place during their storage resulting in mixtures of 2- and 3-t-butylthiophenes (the ratio 97:3) which contained considerable quantities of 2,4-di-t-butylthiophene.Deprotonation of t-butylthiophenium ions in the presence of acetone leads to the formation of respective t-butylsubstituted dimethyldithienylmethanes.