2,3-Dichloroquinoxaline → 2-Chloro-3-(2-methyl-6-(methylthio)pyrimidin-4-yl)quinoxaline

Participants

Reaction Conditions

Reaction Steps

A glass microwave reaction vessel was charged with 2-methyl-4-(methylthio)-6-(tributylstannyl)pyrimidine (1.6 g, 3.73 mmol), 2,3-dichloroquinoxaline (1.484 g, 7.45 mmol, Aldrich) and tetrakis(triphenylphosphine)palladium (0.431 g, 0.373 mmol, Strem Chemicals) in toluene (5 mL). Argon was bubbled through for 2 min. The reaction mixture was stirred and heated at 120° C. for 36 h. The mixture was cooled to room temperature, filtered through Celite® (diatomaceous earth) washing with 10% methanol-DCM, and the filtrate was concentrated. The crude product was purified by chromatography through a Redi-Sep pre-packed silica gel column (40 g), eluting with a gradient of 0-100% DCM-hexane to give 2-chloro-3-(2-methyl-6-(methylthio)pyrimidin-4-yl)quinoxaline (0.8 g, 2.64 mmol, 70.9% yield) as a white solid. 1H NMR (400 MHz, d6-DMSO) δ 8.23 (dd, J=8.02, 1.56 Hz, 1H); 8.13-8.19 (m, 1H); 7.96-8.05 (m, 2H); 7.73 (s, 1H); 2.67 (s, 3H); 2.61 (s, 3H). m/z (ESI, +ve ion) 303 (M+H)+.

Provenance & Evidence