Isomerization of 3H‐ to 2H‐[1]Benzothieno[3,2‐b]pyrroles and Synthesis of the First Merocyanine Dyes Based on Them

(E)-1-([1,1′-Biphenyl]-4-yl)-2-(1,3,3-trimethylindolin-2-ylidene)ethanone

“…For background to the Fisher base (2,3-dihydro-1H-1,3,3trimethyl-2-methyleneindole), see: Minkin (2004); Przhiyalgovskaya et al (1987). For applications of derivatives of the Fisher base in materials and organic synthesis, see: Corns et al (2009); Shimkin et al (2006); Song et al (2005); Tarshits et al (2005); Cui & Kim (2004).…”

“…Products with different skills to work as switches have been used in optoelectronics (Shimkin et al, 2006), as organic electroluminescent materials (Cui & Kim, 2004) and dyes (Song et al, 2005). Moreover, the enaminoketone derivatives of the Fischer base, like the title compound, are important intermediates for the synthesis of spiropyrans and spirooxazines (Corns et al, 2009), as well as for the preparation of acetylenic products via enaminoketone fragmentation (Tarshits et al, 2005).…”

Toward accessible 3H-pyrroles

“…They display a rich chemistry owing to their proneness to diverse rearrangements, addition and cycloaddition reactions. [1][2][3][4][5][6] Some 3Н-pyrroles exhibit antitumor and antimicrobial activities. [7][8][9] The quantum chemical calculations (MP2/6-311++G**//B3LYP/6-31G**) show that the total electronic energy of 3H-pyrroles exceeds that of their aromatic 1H-isomer by 12-17 kcal/mol.…”

7-Nitro- and 7-aminosubstituted spiropyrans of 1-benzothieno[3,2-b]pyrrole

“…Recently, we have developed an efficient method for the synthesis of photochromic spiro compounds [5,6] and merocyanine dyes [7] based on close analogues of indole -thienopyrroles, and studied their spectral properties [8,9]. In this work, we present the synthesis of nitro-substituted spiropyrans of benzothienopyrrole series and the development of regioselective method for the reduction of nitro-to amino group in spiropyran and thienopyrroline systems.…”