Separation and characterization of chloroform-soluble preasphaltenes in non-distillable coal liquids was written by Allen, Todd W.;Hurtubise, Robert J.;Silver, Howard F.. And the article was included in Fuel in 1987.Computed Properties of C7H5N3 This article mentions the following:
N compounds and hydroxy-aromatics from CHCl3-soluble/PhMe-insoluble preasphaltenes of a Kentucky coal-liquid sample were characterized by elemental anal., IR spectroscopy and field-ionization mass spectrometry. A similar approach was used for the general characterization of the pyridine-soluble/CHCl3-insoluble preasphaltenes. A new HPLC method was applied for the separation of a N-compound fraction and a hydroxy-aromatic fraction from the CHCl3-soluble/PhMe-insoluble preasphaltenes. The chromatog. method was very selective in separating polar N compounds and polar hydroxy-aromatics The separation order within a given fraction was based on increasing polarity of the compounds Spectral results indicated that the CHCl3-soluble preasphaltenes were composed of structures with mol. weights ≈ 200-800 and were predominantly mono- and dihydroxy compounds In addition, nonhydroxy compounds that contained pyrrolic functionality were present. Solubility information for the preasphaltenes in various solvents was also obtained. In the experiment, the researchers used many compounds, for example, Pyrido[2,3-b]pyrazine (cas: 322-46-3Computed Properties of C7H5N3).
Pyrido[2,3-b]pyrazine (cas: 322-46-3) belongs to pyrazine derivatives. Pyrazinesare six-membered aromatic heterocyclic organic compounds with two nitrogen atoms at 1,4-positions. Pyrazine is a weaker base (pKb = 13.4) than pyridine (pKb = 8.8), pyrimidine (pKb = 12.7). Pyrazines undergo nearly all of the same reactions as pyrimidines, from nucleophilic substitution (SNAr) to palladium-catalyzed cross coupling reactions.Computed Properties of C7H5N3