反应详情

To a solution of 4-chloroimidazo[1,5-a]quinoxaline 3-carboxylic acid ethyl ester (5.5 g) in acetonitrile (120 ml) was added ethyl carbazate (9 g) and triethylamine (20 ml) with stirring. The mixture was refluxed for 18 hours, then evaporated under water aspirator vacuum to dryness. The residue was taken up in chloroform, washed with water, dried by magnesium sulfate, concentrated to a small volume, then put through a silica gel dry column (2% methanol in chloroform as eluant). From column the product was isolated as an off-white solid (4 g, 58% yield). Recrystallized from a mixture of chloroform and hexane, m.p. 126°-128° C.

1. temperatureThe mixture was refluxed for 18 hours
2. customevaporated under water
3. washwashed with water
4. dry with materialdried by magnesium sulfate
5. concentrationconcentrated to a small volume
6. dry with materialdry column (2% methanol in chloroform as eluant)