de Oliveira, Jaismary G. B. et al. published their research in Acta Crystallographica, Section E: Structure Reports Online in 2012 | CAS: 70291-62-2

2-Amino-5,6-dihydro-4H-cyclopenta[b]thiophene-3-carbonitrile (cas: 70291-62-2) belongs to nitriles. Trimerization of aromatic nitriles requires harsh reaction conditions, high temperatures, long reaction times, and pressure. In conventional organic reductions, nitrile is reduced by treatment with lithium aluminium hydride to the amine. Reduction to the imine followed by hydrolysis to the aldehyde takes place in the Stephen aldehyde synthesis, which uses stannous chloride in acid.Reference of 70291-62-2

Ethyl 2-(3-phenylthioureido)-5,6-dihydro-4H-cyclopenta[b]thiophene-3-carboxylate was written by de Oliveira, Jaismary G. B.;Mendonca, Francisco J. B. Jr.;de Lima, Maria do Carmo A.;de Simone, Carlos A.;Ellena, Javier A.. And the article was included in Acta Crystallographica, Section E: Structure Reports Online in 2012.Reference of 70291-62-2 This article mentions the following:

In the title compound, C17H18N2O2S2, the angle between the mean plane defined by the atoms of the 5,6-dihydro-4H-cyclopenta[b]thiophene moiety (root-mean-square deviation = 0.19 鑴? and the Ph ring is 72.8鎺?2). The mol. conformation is stabilized by an intramol. N-H璺矾璺疧 interaction, which generates an S(6) ring motif. In the crystal, pairs of N-H璺矾璺疭 H bonds link the mols. to form inversion dimers with an R22(8) ring motif. Crystallog. data and at. coordinates are given. In the experiment, the researchers used many compounds, for example, 2-Amino-5,6-dihydro-4H-cyclopenta[b]thiophene-3-carbonitrile (cas: 70291-62-2Reference of 70291-62-2).

2-Amino-5,6-dihydro-4H-cyclopenta[b]thiophene-3-carbonitrile (cas: 70291-62-2) belongs to nitriles. Trimerization of aromatic nitriles requires harsh reaction conditions, high temperatures, long reaction times, and pressure. In conventional organic reductions, nitrile is reduced by treatment with lithium aluminium hydride to the amine. Reduction to the imine followed by hydrolysis to the aldehyde takes place in the Stephen aldehyde synthesis, which uses stannous chloride in acid.Reference of 70291-62-2

Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts