In this study, we developed an efficient strategy for constructing thieno[3,2-
b]thiophene molecules from 3-nitrothiophenes, containing carbonyl fragments at the C-2 and C-5 atoms, by nucleophilic aromatic substitution of the nitro group in these substrates. It was shown that the reaction of
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In this study, we developed an efficient strategy for constructing thieno[3,2-
b]thiophene molecules from 3-nitrothiophenes, containing carbonyl fragments at the C-2 and C-5 atoms, by nucleophilic aromatic substitution of the nitro group in these substrates. It was shown that the reaction of 3-nitrothiophene-2,5-dicarboxylates with thiophenols, thioglycolates and 2-mercaptoacetone in the presence of K
2CO
3 proceeds rapidly via nucleophilic displacement of the nitro group with the formation of 3-sulfenylthiophene-2,5-dicarboxylates. Further treatment of the resulting thiophene-2,5-dicarboxylates, which have -SCH
2CO
2Alk or -SCH
2COMe moiety at C-3 atom, with sodium alcoholates afford obtaining 2,3,5-trisubstituted thieno[3,2-
b]thiophene derivatives according to the Dieckman condensation. In turn, the reaction of methyl 5-formyl-4-nitrothiophene-2-carboxylate with methyl thioglycolate or 2-mercaptoacetone in the presence of K
2CO
3 proceeds to directly form 2,5-disubstituted thieno[3,2-
b]thiophenes.
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