The author of 《Multi-component reaction to access a library of polyfunctionally substituted 4,7-dihydropyrazolo[3,4-b]pyridines》 were Aggarwal, Ranjana; Kumar, Suresh; Singh, Gulshan. And the article was published in Synthetic Communications in 2019. Formula: C9H7NO The author mentioned the following in the article:
A practical approach to polyfunctionally substituted 4,7-dihydropyrazolo[3,4-b]pyridine derivatives from heteroaryl hydrazine, 3-aryl-3-oxopropanenitriles and aldehydes have been described in the report. The present catalyst-free protocol involves the intermediacy of 5-aminopyrazole and α-cyanochalcone, which undergoes in situ Michael addition to afford title compounds in moderate to good yields. All the steps were conducted concomitantly to render the procedure as practical and straightforward as possible. The expeditious synthetic protocol experiment takes less than one hour and shows broad substrate scope. In the part of experimental materials, we found many familiar compounds, such as 3-Oxo-3-phenylpropanenitrile(cas: 614-16-4Formula: C9H7NO)
3-Oxo-3-phenylpropanenitrile(cas: 614-16-4) has been used to produce 2-benzoyl-3-furan-2-yl-acrylonitrile. It is an active methylene compound, useful in heterocyclic synthesis, e.g. polyfunctional pyridines and pyrimidines.Formula: C9H7NO
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts