A new synthesis of benzo[b]thiophenes and benzo[c]thiophenes by annulation of disubstituted thiophenes was written by Terpstra, Jan W.;Van Leusen, Albert M.. And the article was included in Journal of Organic Chemistry in 1986.Computed Properties of C6H5NS This article mentions the following:
Nine newly prepared ortho-disubstituted thiophenes I (R = CHO, CO2Me, cyano; n = 1, 2) and II (R = CO2Me, cyano, n = 1, 2) react with Michael acceptors to form benzo[b]-, e.g. III, and benzo[c]thiophenes, e.g. IV. This novel annulation process is specifically suited to form benzothiophenes with substituents in the benzene moiety. Substitution patterns so obtained are uncommon and difficultly accessible otherwise; none of the 31 benzothiophenes described in this paper were reported previously. In the experiment, the researchers used many compounds, for example, 3-Methylthiophene-2-carbonitrile (cas: 55406-13-8Computed Properties of C6H5NS).
3-Methylthiophene-2-carbonitrile (cas: 55406-13-8) belongs to nitriles. Nitrile compounds can be prepared by the incorporation of a cyanide source through C–C bond formation or by dehydration of primary carboxamides. Asymmetric bioreduction of nitriles is an attractive route to produce optically active nitriles as current metal-catalyzed hydrogenations tend to have low reactivity.Computed Properties of C6H5NS
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts