On October 31, 1980, Hollstein, Ulrich; Krisov, Galen E. published an article.Category: quinoxaline The title of the article was Carbon-13 NMR studies on some 5-substituted quinoxalines. And the article contained the following:
The 11 quinoxalines I (R = NO2, NH2, CO2H, OMe, Me, OH, F, Cl, Br, I, CN) were prepared and their 13C NMR were recorded in (D3C)2SO and assigned. The observed chem. shifts agree with those calculated from C6H6 substituent parameters and are close to those of corresponding carbons in 1-substituted phenazines and naphthalenes, except for the quinoxaline C-4a and C-8a which, due to their proximity to N, are downfield relative to those of the naphthalenes. The spectrum of I (R = F) was recorded in a range of solvents: in each case there was a low 2J(CF) for C-4a and no C-F spin-spin splitting for the 3-bond coupling of C-8a. Linear relationships exist between the Q parameter of the substituent and the chem. shift of C-4a, -5, and -6 and between the chem. shift of C-8 and the Hammet σp parameter of the substituent. The experimental process involved the reaction of 5-Chloroquinoxaline(cas: 62163-09-1).Category: quinoxaline
The Article related to nmr carbon quinoxaline substituent effect, Physical Organic Chemistry: Spectral and Related Studies and other aspects.Category: quinoxaline
Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider