Carbonic Acid → 5-Chloro-3-(3-fluorophenyl)-2-methylquinoxaline

Participants

Reaction Conditions

Reaction Steps

A mixture of 3,5-dichloro-2-methylquinoxaline (Prepared in Example 85, 0.3361 g, 1.577 mmol), 3-fluorobenzeneboronic acid (0.2428 g, 1.735 mmol), tetrakis(triphenylphosphine)palladium (0.09114 g, 0.07887 mmol), and sodium carbonate anhydrous (0.8360 g, 7.887 mmol) in CH3CN—H2O (3:1) (16.00 mL) was stirred at 100° C. After 3.5 h, the mixture was cooled to room temperature and partitioned between EtOAc (100 mL) and water (100 mL). The organic layer was washed with brine (50 mL×2), dried over Na2SO4, filtered, and concentrated under reduced pressure to give red syrup. The red syrup was purified by silica gel column chromatography on a 40 g of Redi-Sep™ column using 0 to 50% gradient of EtOAc in hexane over 14 min and then 50% isocratic of EtOAc for 10 min as eluent to give 5-chloro-3-(3-fluorophenyl)-2-methylquinoxaline as a solid: 1H NMR (400 MHz, DMF) δ ppm 8.05 (1H, dd, J=8.4, 1.4 Hz), 8.00 (1H, dd, J=7.6, 1.4 Hz), 7.83 (1H, dd, J=8.4, 7.6 Hz), 7.60-7.67 (3H, m), 7.38-7.46 (1H, m), 2.74 (3H, s); LC-MS (ESI) m/z 273.1 [M+H]+.

Provenance & Evidence