Synthesis and application of 4-(coumarin-3-yl)thiophenes was written by Sabnis, Ram W.;Rangnekar, Dinesh W.. And the article was included in Sulfur Letters in 1993.Computed Properties of C12H14N2O4S This article mentions the following:
A facile synthesis of (4-coumarin-3-yl)thiophenes I (R1 = H, OMe, R2 = H, OH, OMe, NEt2, R3 = H, OH, OMe, Cl, NO2, R4 = H, OMe) was achieved by the condensation of 2-acetamido-3-cyano-4-carbethoxymethylene-5-carbethoxythiophene II with selected o-hydroxy aldehydes III in the presence of piperidine. The key intermediate II was synthesized by cyclocondensation of EtO2CCH2COCH2CO2Et, sulfur, and malononitrile by a Gewald synthesis followed by acetylation. I were applied on polyester fibers as fluorescent disperse dyes and their fluorescence and dyeing properties were studied. In the experiment, the researchers used many compounds, for example, Ethyl 5-amino-4-cyano-3-(2-ethoxy-2-oxoethyl)thiophene-2-carboxylate (cas: 58168-20-0Computed Properties of C12H14N2O4S).
Ethyl 5-amino-4-cyano-3-(2-ethoxy-2-oxoethyl)thiophene-2-carboxylate (cas: 58168-20-0) belongs to nitriles. The electronic structure of nitriles is very similar to that of an alkyne with the main difference being the presence of a set of lone pair electrons on the nitrogen. Alkyl nitriles are sufficiently acidic to undergo deprotonation of the C-H bond adjacent to the CN group.Strong bases are required, such as lithium diisopropylamide and butyl lithium. The product is referred to as a nitrile anion. Computed Properties of C12H14N2O4S
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts