With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.34117-90-3,3-Chloroquinoxalin-2-amine,as a common compound, the synthetic route is as follows.
tBuLi (2.0 mL, 3.28 mmol, 1.64 M in pentane) was added dropwise to a solution of diphenylphosphane (0.56 mL, 3.22 mmol) in Et2O (10 mL) at 70C. After stirring for 15 min at 30C the yellow suspension was cooled again, and a solution of 2a (578 mg, 3.22 mmol) in Et2O (10 mL) was added slowly at 70C (rapid addition leads to a brown side product) and stirred for 1 h. Then the mixture was allowed to warm to room temperature and stirred overnight. 31P NMR monitoring displayed signals for 3a and Ph2PH in an intensity ratio of 17:83%. The mixture was cooled to 80C, and a second equivalent of cold tBuLi in pentane (2.0 mL) was added. The mixture was allowed to warm to room temperature (brown colour) und stirred for 2 d (31P NMR signal ratio of 3a and Ph2PH, 60:40%). The precipitate was filtered off and washed with ether. (The brown colour vanishes on contact with traces of moisture.) After the major part of the solvent was removed in vacuum the product started to crystallize. The mixture was overlayered with hexane and after some hours filtered, washed with hexane/Et2O and dried in vacuum to give 440 mg (42%) orange-yellow crystals. Mp: 158-160C. Single crystals were obtained from warm saturated hexane/Et2O solution. 1H NMR (CDCl3) d: 5.31 (br s, 2H, NH2), 7.29 (superimposed td, 3J = 8, 7, 4J?1.2 Hz, 1H, H-6), 7.25-7.35 (m, 7H, aryl), 7.39-7.46 (m, 4H, aryl), 7.48 (td, 3J = 8,7, 4J?1.2 Hz, 1H, H-7), 7.55 (dd, 3J = 8.3, 4J?1.2 Hz, 1H, H-8), 7.72 (dd, 3J = 8.3, 4J?1.2 Hz, 1H, H-5). 13C{1H} NMR (CDCl3) d: 124.70 (CH-6), 125.60 (CH-8), 128.57 (d, 3J = 7.4 Hz, 4 CH-m), 129.51 (2 CH-p), 129.46, 130.34 (CH-5, CH-7), 133.25 (d, 1J = 5.4 Hz, 2 Cq-i), 134.45 (d, 2J = 19.6 Hz, 4 CH-o), 138.78 (d, 3J = 3.3 Hz, Cq-4a), 141.05 (Cq-8a), 149.24 (d, 1J = 13.0 Hz, PCq-3), 153.60 (d, 2J = 24.3 Hz, NCq-2). 31P{1H} NMR (CDCl3) d: 12.1. UV-VIS (c = 3.4¡Á10-5 mol/L) lambdamax(MeOH)/nm (epsilon/dm3 mol-1 -cm-1): 371 (6730), 306 (3560), 244 (19500), 208 (38400). Anal. Calc. for C20H16N3P (329.33): C, 72.94; H, 4.90; N, 12.76. Found: C, 73.07; H, 4.89; N, 12.87%.
34117-90-3, 34117-90-3 3-Chloroquinoxalin-2-amine 817274, aquinoxaline compound, is more and more widely used in various fields.
Reference£º
Article; Adam, Mohamed Shaker S.; Mohamad, Ahmad Desoky; Jones, Peter G.; Kindermann, Markus K.; Heinicke, Joachim W.; Polyhedron; vol. 50; 1; (2013); p. 101 – 111;,
Quinoxaline – Wikipedia
Quinoxaline | C8H6N2 | ChemSpider