New heterocyclic Meisenheimer complexes. Action of methoxide and hydride ions on 2,4-substituted thiophenes and selenophenes was written by Paulmier, Claude;Simonnin, Marie Paule;Chatrousse, Alain Pierre;Terrier, Francois. And the article was included in Tetrahedron Letters in 1973.Electric Literature of C5H2N2O2S This article mentions the following:
Meisenheimer complexes, formed by addition of MeOK to 2,4-disubstituted thiophenes and selenophenes (I; X = S, Se; R, R1 = NO2, CN), were assigned structure II (R2 = OMe) from NMR data. Addition of Me4NBH4 to I (X = S; R = NO2, CN, R1 = NO2) gave analogous II (R = NO2, CN; R1 = NO2; R2 = H), but with I (X = S, R = NO2, R1 = CN; X = Se, R, R1 = NO2, CN) ring-opening occurred. In the experiment, the researchers used many compounds, for example, 4-Nitrothiophene-2-carbonitrile (cas: 42137-24-6Electric Literature of C5H2N2O2S).
4-Nitrothiophene-2-carbonitrile (cas: 42137-24-6) belongs to nitriles. Nitrile function is a very important functional group because it can be manipulated to other functional groups such as carboxylic acid by hydrolysis or amine by reduction, respectively. In addition, Nitriles can react with alkynes, which leads to an increase in carbon chain length (carbocyanation).Electric Literature of C5H2N2O2S
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts