Synthesis of 2-aminochromene derivatives from 1-(2-imino-2H-chromen-3-yl)pyridin-1-ium perchlorates and nitromethane in basic medium was written by Storozhenko, Olga A.;Yue, Xiaoyi;Festa, Alexey A.;Varlamov, Alexey A.;Voskressensky, Leonid G.. And the article was included in Chemistry of Heterocyclic Compounds (New York, NY, United States) in 2020.COA of Formula: C7H7ClN2 This article mentions the following:
Novel 2-amino-4-(nitromethylidene)chromenes were obtained as a result of the reaction of 1-(2-imino-2H-chromen-3-yl)pyridinium perchlorates and nitromethane by the action of DBU at reflux in trifluoroethanol. The starting 2-iminochromenes are readily accessible from the corresponding salicylic aldehydes and quaternary cyanomethyl pyridinium salts. The reaction is tolerant to substituents of different nature (alkyl, alkoxy, halogen); a limitation is the presence of strong electron-withdrawing substituents in the benzene ring of chromene. During the reaction, the products precipitate and can be isolated by filtration. In the experiment, the researchers used many compounds, for example, 1-(Cyanomethyl)pyridin-1-ium chloride (cas: 17281-59-3COA of Formula: C7H7ClN2).
1-(Cyanomethyl)pyridin-1-ium chloride (cas: 17281-59-3) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.COA of Formula: C7H7ClN2