反应详情

4-Oxo-4,5-dihydroimidazo[1,5-a]quinoxaline 3-carboxylic acid ethyl ester (9 g) was suspended in 200 ml of phosphorus oxychloride and the mixture was heated with stirring until it became a clear solution. After cooling to room temperature, the solution was concentrated under vacuum. The residual oil was taken up in chloroform and was put through a short silica gel dry column (chloroform as eluant). The product was obtained from column as an off-white colored solid (4.5 g, 47% yield), m.p. 128°-130° C.

1. temperaturethe mixture was heated
2. concentrationthe solution was concentrated under vacuum
3. dry with materialdry column (chloroform as eluant)