An effective route to dithieno[3,2- B:2′,3′- D ]thiophene-based hexaheteroacenes / N. S. Demina, R. A. Irgashev, N. A. Kazin [et al.] // Synlett. - 2021. - Vol. 32, № 10. - P1009-1013 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): BENZOTHIENOTHIENOTHIENOINDOLES -- AMINOTHIOPHENES -- ARYLHYDRAZINES Аннотация: A series of 12H-[1]benzo[4′′,5′′]thieno[2′′,3′′:4′,5′]thieno[2′,3′:4,5]thieno[3,2-b]indoles were efficiently prepared in three steps starting from available benzo[b]thieno[2,3-d]thiophen-3(2H)-ones. These fused ketones were treated with the Vilsmeier reagent and hydroxylamine hydrochloride to give the corresponding 3-chlorobenzo[b]thieno[2,3-d]thiophene-2-carbonitriles, which then reacted with methyl sulfanylacetate to form methyl 3-aminobenzo[4′,5′]thieno[2′,3′:4,5]thieno[3,2-b]thiophene-2-carboxylates, in accordance with the Fiesselmann thiophene synthesis protocol. Finally, the desired N,S-heterohexacenes were obtained by conversion of these fused 3-aminothiophene-2-carboxylates into the corresponding 3-aminothiophene intermediates, which acted as synthetic equivalents of thiophen-3(2H)-ones, followed by their acid-promoted reaction with arylhydrazines, in accordance with the Fischer indolization procedure. |