σ-Adducts of heterocycles with nucleophiles. XXII. Nuclear magnetic resonance data of pyrido[2,3-b]pyrazines and their σ-adducts with amide ion and water was written by Nagel, A.;Van der Plas, H. C.;Geurtsen, G.;Van Veldhuizen, A.. And the article was included in Journal of Heterocyclic Chemistry in 1979.HPLC of Formula: 322-46-3 This article mentions the following:
The 13C NMR of I [R = R1 = R2 = H (II); R = 3-Ph, O-Me3C, 2-Cl (III), R1 = R2 = H; R = R1 = H, R2 = 6-Cl (IV), 6-NH2; R = 2-Cl (V), 3-Ph, 3-Me3C, 2-Me3C, 2-NH2NH, R1 = H, R2 = 6-Cl; R = 2-Ph, R1 = 3-Ph, R2 = H, 6-F, 6-Cl, 6-Br], II-2-13C, III–2–13C, IV–2–13C, V–2–13C, VI (R = H, Cl), and VII are used to assign the spectrum of II. 13C NMR established the structure and the formation of VIII (R = H, Me3C) from the addition of KNH2-NH3 to the corresponding I; 1H NMR established the formation of IX under these conditions. 13C NMR also indicated that II is not hydrated in neutral aqueous solution; II in N HCl gives X. The ring contraction mechanism of I with NH2– to give 1H-imidazo[4,5-b]pyridine is discussed. In the experiment, the researchers used many compounds, for example, Pyrido[2,3-b]pyrazine (cas: 322-46-3HPLC of Formula: 322-46-3).
Pyrido[2,3-b]pyrazine (cas: 322-46-3) belongs to pyrazine derivatives. Pyrazine has the elements of symmetry for the point group D2h. It has three mutually perpendicular two-fold axes. It also has three mutually perpendicular planes of symmetry. As a result, pyrazine also has a centre of symmetry. Pyrazines undergo nearly all of the same reactions as pyrimidines, from nucleophilic substitution (SNAr) to palladium-catalyzed cross coupling reactions.HPLC of Formula: 322-46-3