Structure
2-aminonicotinic acid (or 2-aminopyridine-3-carboxylic acid, abbreviated ANA) can be a model compound for reactions containing carboxylic and amino groups attached to the pyridine ring. X-ray diffraction studies have shown that in the molecular crystal phase, ANA occurs as a zwitterion in which protonation occurs at the nitrogen atom of the pyridine ring. Infrared spectra of ANA molecular crystal have confirmed that intra- and intermolecular hydrogen bonds are present in its structure. Karabacak et al. investigated the tautomerism of ANA using electronic structure calculations (B3LYP/6-311++G(d,p)) and identified four amino tautomers. Furthermore, Nayak and Dogra optimized the structures of two amino and two imino structures at the B3LYP/6-31G** level. On the basis of both experimental data (absorption and fluorescence spectra) and electronic structure calculations, these authors concluded that ANA is present in solutions as the amino form in both the S0 and S1 states, whereas the imino forms are absent. ANA exists as a molecular species in non-polar and polar aprotic solvents and as a zwitterion in polar protic solvents[1].
Chemical Properties
Off-white to light yellow crystalline powder
Uses
2-Aminopyridine-3-carboxylic acid can be used as:
- A ligand to prepare copper(II)-organic coordination compounds.
- A reactant to prepare pyrido[2′,1′:2,3]imidazo[4,5-c]isoquinolines by reacting with trimethylsilyl cyanide and phthalaldehyde.
- A reactant to synthesize organo-soluble and thermally stable poly(thiourea-amide-imide) polymers.
Uses
A component of hair dyes.
Definition
ChEBI: An aminonicotinic acid in which the amino group is situated at position 2 of the pyridine ring.
References
[1] M. Pagacz-Kostrzewa . “Phototransformations of 2-aminonicotinic acid resolved with matrix isolation infrared spectroscopy and ab initio calculations.” Journal of Photochemistry and Photobiology A-chemistry 410 (2021): Article 113187.
