Synthesis of aryl-substituted thieno[3,2-b]thiophene derivatives and their use for N,S-heterotetracene construction

• Nadezhda S. Demina,
• Nikita A. Kazin,
• Nikolay A. Rasputin,
• Roman A. Irgashev and
• Gennady L. Rusinov

Beilstein J. Org. Chem. 2019, 15, 2678–2683, doi:10.3762/bjoc.15.261

• . N. Yeltsin, Mira St., 19, Ekaterinburg, 620002, Russia 10.3762/bjoc.15.261 Abstract Fiesselmann thiophene synthesis was applied for the convenient construction of thieno[3,2-b]thiophene derivatives. Thus, new 5- or 6-aryl-3-hydroxythieno[3,2-b]thiophene-2-carboxylates were obtained by condensation

• ketones were used to synthesize new N,S-heterotetracenes, namely 9H-thieno[2',3':4,5]thieno[3,2-b]indoles by their treatment with arylhydrazines in accordance with the Fischer indolization reaction. Keywords: Fiesselmann thiophene synthesis; Fischer indole synthesis; N,S-heteroacene; thieno[3,2-b

• should be noted that the initial 3-aminoesters 1 are known compounds and can be obtained by the Fiesselmann thiophene synthesis from aryl-substituted acrylonitriles bearing a good leaving group at the C-3 position [22][23][24]. Methyl 3-chlorothiophene-2-carboxylates 2a–k were further involved in the