Sodium Carbonate → HCID 89782036, compound

Participants

Reaction Conditions

Reaction Steps

Argon was bubbled into a mixture of 8-bromo-2-chloroquinoxaline (210e; 0.50 g, 2.05 mmol), Na2CO3 (1.09 g, 10.27 mmol), Pd(PPh3)4 (Strem; 0.119 g, 0.103 mmol), 2,6-dimethylbenzeneboronic acid (Aldrich; 0.31 g, 2.05 mmol) in 9 mL ACN and 3 mL water for 1 min. The reaction was sealed and heated to 80° C. overnight. The temperature was increased to 100° C. and the reaction was heated 8 h. The reaction was partitioned between water and DCM. The aqueous layer was extracted with DCM 3 times, and the combined organics were dried over anhydrous Na2SO4, filtered, and concentrated in vacuo. The material was treated with MeOH/DCM and adsorbed onto 2 g silica gel, dried, and purified by silica gel chromatography (40 g ISCO gold column) using 0-30% EtOAc/hexanes. The product-containing fractions were concentrated to afford 8-bromo-2-(2,6-dimethylphenyl)quinoxaline (0.08 g, 0.25 mmol, 12% yield) as an oil that solidifies very slowly to a white solid. 1H NMR (400 MHz, CDCl3) δ ppm 8.83 (1H, s), 8.09-8.19 (2H, m), 7.67 (1H, dd, J=8.2, 7.6 Hz), 7.27-7.33 (1H, m), 7.16-7.23 (2H, m), 2.18 (6H, s). m/z (ESI, +ve) 313.0/315.0 (M+H)+.

Provenance & Evidence