Synthesis and electrophilic trichloromethylation of 2,4-dialkylthiophenes. Some transformations of 2,4-di-tert-butyl-5-(trichloromethyl)thiophene

The disproportionation products of the C-protonation of 5-tert-butyl-2-methyl- and 2-ethylthiophene first give 4-tert-butyl-2-methyl- and 2-ethylthiophene. We studied the electrophilic trichloromethylation of a series of 2,4-dialkyl thiophenes and showed that the reaction goes smoothly only for the most sterically hindered 2,4-di-tertbutyl-thiophene. We studied the reaction of 2,4-di-tert-butyl-5-(trichloromethyl)thiophene with some O- and N-nucleophiles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1040–1045, August, 1993.