19506-17-3Relevant articles and documents
POLYCYCLIC TLR7/8 ANTAGONISTS AND USE THEREOF IN THE TREATMENT OF IMMUNE DISORDERS
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Paragraph 00460, (2017/07/06)
The present invention relates to compounds of Formula (I) and pharmaceutically acceptable compositions thereof, useful as toll-like receptor 7/8 (TLR7/8) antagonists. In Formula (I), Ring A is aryl or heteroaryl; Ring B is aryl or heteroary; and X is C(R4)2, O, NR4, S, S(R4), or S(R4)2.
13C Nuclear Magnetic Resonance Spectra of Quinoxaline Derivatives
McNab, Hamish
, p. 357 - 364 (2007/10/02)
The 13C n.m.r. spectra of a series of 5-, 6-, and 2-substituted quinoxalines have been analysed by consideration of their 1H coupled spectra.Typical values of the coupling constants are: C(2,3), 1JCH 181.9, 2JCH 11.4, C(5,8), 1JCH 162.6, 3JCH 6.5, C(6.7), 1JCH 159.4, 3JCH 9.1; C(9), 3JCH(2) = 3JCH(7) = 10.0, 3JCH(5) 5.4; C(10), 3JCH(3) = 3JCH(6) = 10.0, 3JCH(8) 5.4 Hz.The magnitudes of the coupling constants in the benzenoid ring are similar to these for the corresponding positions in naphthalene, but application of naphthalene chemical shift substitutions effects leads in some cases to the wrong peak sequence in the related quinoxalines.Within the quinoxaline series itself, however, acceptable additivity of substituent effects is found (+/- 0.8 p.p.m.), provided that the reference compounds are carefully chosen.Analysis of mixtures of quinoxalines from substituted o-phenylenediamines and α-oxo-aldehydes is possible by consideration of the multiplicity of the ring-junction quaternary carbon signals in the fully coupled spectra.
Carbon-13 NMR Studies on some 5-Substituted Quinoxalines
Hollstein, Ulrich,Krisov, Galen E.
, p. 300 - 304 (2007/10/02)
Eleven 5-substituted quinoxalines (NO2, NH2, COOH, OCH3, CH3, OH, F, Cl, Br, I, CN, the latter five not reported previously) have been synthesized by standard methods.Their 13C NMR spectra have been measured in DMSO-d6 and assigned on the basis of substituent parameters, by line widths and by intensities.The chemical shifts compare favorably with those calculated using benzene substituent parameters, and are very close to those of corresponding carbons in 1-substituted phenazines.The correlation with the chemical shifts of the corresponding positions in 1-substituted naphthalenes is also close except for those of carbons 4a and 8a in the quinoxalines which, due to their proximity to nitrogen, are downfield (in some cases 12 ppm) of the signals of the corresponding carbons in naphthalene. 5-Fluoroquinoxaline was also measured in CDCl3, CD3COCD3, CD3CN, CD3OD, C6D6 and CD3COOD.In all solvents an abnormally low 2J(CF) (ca. 12 Hz) was found for C-4a and no C-F spin-spin splitting could be detected for the three-bond coupling of C-8a.Similar abnormalities were found in 2-fluoroaniline and 2-fluoroacetanilide.There are linear relationships between the Q parameter of the substituent and the chemical shift of carbons 4a, 5 and 6.A linear relationship also exists between the chemical shift of C-8 ('para' position) and the Hammett ?p parameter of the substituent.
