With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.1392413-56-7,6-Bromo-3-chloro-2-methylquinoxaline,as a common compound, the synthetic route is as follows.
1392413-56-7, INTERMEDIATE: (7-Bromo-3-methyl-quinoxalin-2-yl)-hydrazine (Iln). A mixture of 4-bromo-l- fluoro-2-nitn benzene (99 g), racemic alanine (120 g), and CS2CO3 (440 g) were refluxed for 5h in a mixture of in ethanol (1.2 L) and water (400 mL). After cooling to ambient temperature the mixture was diluted with water (600 mL) and acidified to pH 3. The solid was filtered off and dried to afford 2-(4-bromo-2-nitro-phenylamino)-propionic acid (110 g) as yellow solid. A portion of this material (10 g) was dissolved in AcOH (35 mL), and iron powder (5.8 g) was added. The mixture was stirred at 90 C for 2h, cooled to ambient temperature, and filtered. Most of the volatiles in the filtrate were removed in vacuo. The remaining slurry was diluted in DCM. The organic layer was dried over Na2S04, filtered, and concentrated in vacuo to afford 7-bromo-3-methyl-3,4-dihydro H-qumoxalin- 2-one (6.4 g) as a yellow solid. A larger portion of this material prepared in a similar manner (45 g) was mixed with water (180 mL) and 30% aq hydrogen peroxide (140 mL). The mixture was stirred at 60 C for 6h, cooled and the solid was filtered off, washed with water, and dried to afford 7- bromo-3-methyl-lH-quinoxalin-2-one (36 g) as a yellow solid. A portion of this material (12 g) was stirred in PI1POCI2 (80 mL) at 150 C for 4h. After cooling to ambient temperature, water was added and pH was adjusted to 7 with aqueous ammonia. The precipitated solid was filtered off, washed with water, and dried to afford 6-bromo-3-chloro-2-methyl-quinoxaline (8.0 g) as a yellow solid. A larger portion of this material prepared in a similar manner (16 g) was dissolved in ethanol (250 mL). Hydrazine hydrate (160 mL) was added, and the mixture was refluxed for 3h, cooled to ambient temperature, and most of the volatiles were removed in vacuo. The residue was suspended in water, the solid was filtered off, washed with water, and dried to afford Iln (13 g) as a yellow solid pure for the next step.
1392413-56-7 6-Bromo-3-chloro-2-methylquinoxaline 71520791, aquinoxaline compound, is more and more widely used in various.
Reference£º
Patent; H. LUNDBECK A/S; J?RGENSEN, Morten; BRUUN, Anne, Techau; RASMUSSEN, Lars, Kyhn; LARSEN, Mogens; WO2013/34755; (2013); A1;,
Quinoxaline – Wikipedia
Quinoxaline | C8H6N2 | ChemSpider