Butanedione → 5-Bromo-8-(3,5-dimethoxy-phenyl)-2,3-dimethyl-quinoxaline

Participants

Reaction Steps

A mixture of 4-bromo-3′,5′-dimethoxy-biphenyl-2,3-diamine (Step 85.7) (3 g, 9.3 mmol) and 2,3-butanedione (1 mL, 11.1 mmol, 1.2 equiv) in EtOH (60 mL) was stirred at reflux for 2 h, allowed to cool to rt and stirred for 16 h. Additional 2,3-butanedione (0.4 ml) was added. The reaction mixture was stirred at reflux for 2 h, allowed to cool and concentrated to half of the initial volume. The resulting yellow precipitate was collected vacuum filtration providing 2.9 g of the title compound: ES-MS: 373.1/375.0 [M+H]+; tR=5.60 min (System 1).

Provenance & Evidence