The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Electronic spectra of N-heteroaromatic systems. I. The n-π transitions of monocyclic azines》. Authors are Mason, S. F..The article about the compound:2-Aminoquinazolin-4(3H)-onecas:20198-19-0,SMILESS:O=C1NC(N)=NC2=C1C=CC=C2).Synthetic Route of C8H7N3O. Through the article, more information about this compound (cas:20198-19-0) is conveyed.
The positions and the intensities of the band in the visible and the ultraviolet spectra of monocyclic azines owing to the promotion of an electron from a lone-pair N orbital to a π-orbital of the ring have been measured in the vapor phase and in solution in cyclohexane (I) and H2O. The frequency of the band is determined primarily by the energy of the benzene-like lowest unoccupied π orbital of the azine and by groundstate interaction between lone-pair orbitals on different N atoms. The intensities of the n → π bands of the azines increase with the “”s”” character of the lone-pair N orbitals, but the frequencies of the bands are not greatly affected, owing to orbital-following in the transition. The frequencies (ν) in vapor, νmaximum in I, νmaximum in H2O, all oscillator strength (f) in I, and pKα are given for pyridine, pyrimidine, pyrazine, pyridazine, sym-triazine, 3,5,6-trimethyl-1,2,4-triazine, m-tetrazine.
After consulting a lot of data, we found that this compound(20198-19-0)Synthetic Route of C8H7N3O can be used in many types of reactions. And in most cases, this compound has more advantages.
Reference:
Chiral nitrogen ligands in late transition metal-catalysed asymmetric synthesis—I. Addressing the problem of ligand lability in rhodium-catalysed hydrosilations,
Nitrogen-Containing Ligands for Asymmetric Homogeneous and Heterogeneous Catalysis