2-Amino benzamidoxime

2-Amino benzamidoxime (ABAO compound 6) can react quickly with aldehydes to form stable 1, 2-dihydroquinazoline 3-oxides in aqueous solutions. The 2-Amino benzamidoxime reaction process consists of the formation of a Schiff base as a rate-determining step, followed by rapid intramolecular cyclization. The reaction rate is dependent on pH, indicating that protonated benzamidoxime is involved in the formation of Schiff bases as an internal generalized acid. Substituents on the aromatic ring can increase the alkalinity of the aromatic amine, thus speeding up the reaction. The reactive properties of 2-Amino benzamidoxime make it a potential platform for the development of new bioconjugated strategies, fluorescent probes, and post-translational diversification of genetic coding libraries[1].

[1]Kitov P I, et al. Rapid, hydrolytically stable modification of aldehyde-terminated proteins and phage libraries[J]. Journal of the American Chemical Society, 2014, 136(23): 8149-8152.