反应详情

Pyruvic acid (60 mL, 868 mmol, 1.2 eq) is added at room temperature to a stirred suspension of 4-methoxy-benzene-1,2-diamine (100 g, 724 mmol, 1.0 eq) in 1.8M sulfuric acid aqueous solution (1000 mL). After 24 hours stirring at room temperature, the reaction mixture is neutralized by the addition of 1N sodium hydroxide aqueous solution. The resulting precipitate is filtered and washed with water to afford 7-methoxy-3-methyl-1H-quinoxalin-2-one as a dark purple solid (125 g, 91% yield).

1. filtrationThe resulting precipitate is filtered
2. washwashed with water