Pyrido[2,3-b]pyrazine (cas: 322-46-3) belongs to pyrazine derivatives. Pyrazine derivatives have antitumor, antibiotic, anticonvulsant, antituberculous and diuretic effects as well as kinase, enzymatic and potent tubulin and FtsZ polymerization inhibitory activities. Substituted pyrazines have been found as subunits of multiple synthetically constructed therapeutic agents, as well as several natural products.Application In Synthesis of Pyrido[2,3-b]pyrazine
Some 5-azaquinoxalines and 4-azabenzimidazoles was written by Petrow, V.;Saper, J.. And the article was included in Journal of the Chemical Society in 1948.Application In Synthesis of Pyrido[2,3-b]pyrazine This article mentions the following:
3-Nitro-2-aminopyridine (2.5 g.), 7.5 g. reduced Fe, 15 mL. EtOH, 8 mL. H2O, and 0.5 mL. concentrated HCl, refluxed 1 h., give 75% 2,3-diaminopyridine (I), m. 118.5-19.5° (m.ps. corrected). I (1.5 g.) and 4 g. (CHO)2.NaHSO3 (II) in 20 mL. aqueous EtOH, refluxed 1 h., give 17% 5-azaquinoxaline (III), m. 147-8°; I and Ac2, refluxed 1.5 h. in C6H6, give 40% of the 2,3-di-Me derivative of III, straw, m. 148-9°. 5-Bromo-2-aminopyridine (20 g.), slowly added to 120 mL. H2SO4 (d. 1.4) at 0°, the solution treated dropwise with 3.4 mL. fuming HNO3, and the mixture kept 1 h. at 0°, 1 h. at room temperature, and 1 h. at 50-60°, gives 49% of the 3-NO2 derivative, m. 211-12°; reduction with Fe as above gives 70% 5-bromo-2,3-diaminopyridine (IV), m. 214-15°, decompose 255°. IV (1.9 g.) and 2.6 g. II in 20 mL. EtOH, heated 1 h. on the water bath, give 36% of the 7-Br derivative (V) of III, m. 167°; 1 g. Ac2 and 1.9 g. IV in 40 mL. EtOH, refluxed 30 min., give 66% of the 7-bromo-2,3-dimethyl derivative of III, light gray, m. 150° (decomposition); 2.2 g. Bz2 and 2 g. IV in 60 mL. C6H6, refluxed 1.5 h., give 65% of the 7-bromo-2,3-diphenyl derivative of III, yellow, m. 156-8° [trimethiodide, red, m. 192° (decomposition)]; 1 g. IV and 1.1 g. phenanthrenequinone in 10 mL. AcOH, refluxed 1.5 h., give 7-bromophenanthro[9′,10′,2,3]-5-azaquinoxaline, golden, m. 222°. 3-Nitro-2,6-diaminopyridine (1.5 g.), 4 g. Fe, 10 mL. EtOH, 5 mL. H2O, and 0.5 mL. concentrated HCl, refluxed 10 min., 2 g. Bz2 in EtOH added, and the mixture refluxed an addnl. hr., give 26% 6-amino-2,3-diphenyl-5-azaquinoxaline, light yellow, m. 273°; Ac derivative, m. 268-9°. V (1.4 g.) and 2 mL. 100% H2O2 in 6 mL. AcOH, heated 1 h. at 70°, give 73% of the mono-N-oxide, m. 286° (decomposition); the 2,3-di-Me derivative of III did not react with H2O2 and the product from the 2,3-di-Ph derivative could not be purified. I (700 mg.) and 1 mL. 98% HCO2H, refluxed 1 h., give 52% 4-azabenzimidazole, m. 153-4°. 5-Bromo-2,3-diacetamidopyridine, heated about 2 min. at 315°, gives 50% 6-bromo-2-methyl-4-azabenzimidazole, m. 299°. I (1.1 g.) and 600 mg. CO(NH2)2, heated 30 min. at 130-40°, give 2-hydroxy-4-azabenzimidazole (VI), m. 274°. IV (900 mg.) and 300 mg. CO(NH2)2, heated 45 min. at 160-70°, give the 6-Br derivative of VI, with 0.5 mol. AcOH, m. above 300°. I (1 g.) and 800 mg. CS2 in 20 mL. EtOH, refluxed 5 h., give 58% 4-azabenzimidazole-2-thiol (VII), cream, m. above 300°; 6-Br derivative of VII, light yellow, m. above 300°, results from IV and CS2 or CS(NH2)2. In the experiment, the researchers used many compounds, for example, Pyrido[2,3-b]pyrazine (cas: 322-46-3Application In Synthesis of Pyrido[2,3-b]pyrazine).
Pyrido[2,3-b]pyrazine (cas: 322-46-3) belongs to pyrazine derivatives. Pyrazine derivatives have antitumor, antibiotic, anticonvulsant, antituberculous and diuretic effects as well as kinase, enzymatic and potent tubulin and FtsZ polymerization inhibitory activities. Substituted pyrazines have been found as subunits of multiple synthetically constructed therapeutic agents, as well as several natural products.Application In Synthesis of Pyrido[2,3-b]pyrazine
Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem