Nitriles in heterocyclic synthesis: novel routes to cyclopentenothienopyridines, cyclopentenothienopyrimidenes and cyclopentenopyrrolopyrazoles was written by Harb, Abdel Fattah Ali. And the article was included in Egyptian Journal of Pharmaceutical Sciences in 1992.Safety of 2-Amino-5,6-dihydro-4H-cyclopenta[b]thiophene-3-carbonitrile This article mentions the following:
Aminocyclopentenothiophenecarbonitrile I prepared via an extension to the Gewald reaction, was converted into the cyclopentenothienopyridines II (R = H, NH2) and III by treatment with acrylonitrile, malononitrile and Et cyanoacetate. I was converted into the corresponding cyclopentenothienopyrimidines IV (X = S, R1 = NHPh; X = O, R1 = Me, H) on treatment with Ph isothiocyanate, acetic anhydride and triethylorthoformate resp. Also the corresponding cyclopentenopyrrolopyrazole V was obtained by treating I with hydrazine hydrate. In the experiment, the researchers used many compounds, for example, 2-Amino-5,6-dihydro-4H-cyclopenta[b]thiophene-3-carbonitrile (cas: 70291-62-2Safety of 2-Amino-5,6-dihydro-4H-cyclopenta[b]thiophene-3-carbonitrile).
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. 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. Safety of 2-Amino-5,6-dihydro-4H-cyclopenta[b]thiophene-3-carbonitrile
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts