反应详情

A mixture consisting of 3.3 g. (0.013 mole) of 4,7-dimethoxy-1-ethyl-[1,2,4]triazolo[4,3-a]quinoxaline, 33 ml. of 1N hydrochloric acid and 99 ml. of glacial acetic acid was refluxed for a period of two hours. Upon completion of this step, the reaction mixture was cooled to room temperature and poured over ice/water. The resulting mixture was then stirred for a period of 20 minutes and extracted with ethyl acetate. The latter extract next washed with saturated brine and dried over anhydrous magnisium sulfate. After removal of the drying agent by means of filtration and the solvent by means of evaporation under reduced pressure, there was finally obtained a yellowish solid product which was washed with water and air-dried to constant weight to ultimately afford 1.87 g. (67%) of pure 1-ethyl-4-hydroxy-7-methoxy-[1,2,4]triazolo[4,3-a]quinoxaline, m.p. >250° C.

1. extractionextracted with ethyl acetate
2. extractionThe latter extract next
3. washwashed with saturated brine
4. dry with materialdried over anhydrous magnisium sulfate
5. customAfter removal of the drying agent
6. filtrationby means of filtration
7. customthe solvent by means of evaporation under reduced pressure, there
8. customwas finally obtained a yellowish solid product which
9. washwas washed with water
10. customair-dried to constant weight to ultimately afford 1.87 g