With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.1204-75-7,3-Oxo-3,4-dihydroquinoxaline-2-carboxylic acid,as a common compound, the synthetic route is as follows.
1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (149 mg, 0.777 mmol) and 1-hydroxybenzotriazole monohydrate (105 mg, 0.777 mmol), were added to a methylene chloride solution (5.0 ml) of the resulting compound (180 mg, 0.518 mmol) and 3-hydroxyquinoxaline-2-carboxylic acid (148 mg, 0.777 mmol), at room temperature, under nitrogen stream, followed by further addition of triethylamine (0.289 ml, 2.07 mmol), and stirring was carried out at room temperature overnight. The reaction solution was poured into a 2N aqueous hydrochloric acid solution, followed by extraction with ethyl acetate and sequential washing with water, a saturated aqueous sodium hydrogencarbonate solution, water and saline, and then the resulting organic layer was dried over anhydrous sodium sulfate. After the organic layer was concentrated and the resulting residue was purified by a medium-pressure preparative liquid chromatograph (manufactured by Biotage, Inc., 25+M), the residue resulting from concentration was suspended in a mixed solvent of methylene chloride-diethyl ether, and the solid substance was collected by filtration to afford the desired title compound (113 mg, yield 45%) as a pale yellow solid. 1H-NMR (DMSO-d6, 400 MHz) delta: 12.86 (1H, s), 10.19 (1H, s), 7.97 (1H, t, J=7.0 Hz), 7.61 (1H, s), 7.53 (1H, s), 7.36 (1H, s), 7.26 (2H, t, J=7.0 Hz), 6.86 (2H, t, J=7.0 Hz), 5.09-5.07 (1H, m), 4.57-4.55 (1H, m), 4.01-3.68 (4H, m), 2.21-2.02 (5H, m), 1.14-1.11 (6H, m). IR (KBr) cm-1: 2960, 1690, 1640, 1490, 1240, 1150. MS (FAB, m/z): 483 (M+H)+. HRMS (ESI, m/z): 483.1797 (Calcd for C25H28ClN4O4: 483.1799).
As the paragraph descriping shows that 1204-75-7 is playing an increasingly important role.
Reference£º
Patent; Daiichi Sankyo Company, Limited; EP2258697; (2010); A1;,
Quinoxaline – Wikipedia
Quinoxaline | C8H6N2 | ChemSpider