Commercial Zinc Oxide: A Facile, Efficient, and Eco-friendly Catalyst for the One-Pot Three-Component Synthesis of Multisubstituted 2-Aminothiophenes via the Gewald Reaction was written by Tayebee, Reza;Ahmadi, S. Javad;Rezaei Seresht, Esmaeil;Javadi, Farzad;Yasemi, Mohammad A.;Hosseinpour, Mohsen;Maleki, Behrouz. And the article was included in Industrial & Engineering Chemistry Research in 2012.Electric Literature of C8H8N2S This article mentions the following:
An eco-friendly, simple, and effective protocol is developed for the synthesis of various multisubstituted 2-aminothiophenes. In the presence of a catalytic amount of ZnO (5 mol %), ketones or aldehydes, malononitrile and elemental sulfur were converted to the corresponding 2-aminothiophene derivatives in moderate to high yields (27%-70%) under solvent-free conditions at 100 °C. Zinc oxide as an efficient, readily available, and reusable catalyst, showed very good catalytic activity for the synthesis of 2-aminothiophene derivatives Thus far, little research has been reported on the Gewald reaction under solvent-free conditions; to the best of our knowledge, this is the first time that it has been proposed as an inexpensive and readily available catalyst for use in the target synthetic route. In the experiment, the researchers used many compounds, for example, 2-Amino-5,6-dihydro-4H-cyclopenta[b]thiophene-3-carbonitrile (cas: 70291-62-2Electric Literature of C8H8N2S).
2-Amino-5,6-dihydro-4H-cyclopenta[b]thiophene-3-carbonitrile (cas: 70291-62-2) belongs to nitriles. There has been no report on the microbial biosynthesis of nitriles and the physiological function of such enzymes, nor was it not even known whether aliphatic and aromatic nitriles are biological compounds or just petrochemicals. Some nitriles are manufactured by heating carboxylic acids with ammonia in the presence of catalysts. This process is used to make nitriles from natural fats and oils, the products being used as softening agents in synthetic rubbers, plastics, and textiles and for making amines.Electric Literature of C8H8N2S
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts