反应详情

1-(4-Chlorophenyl)-3-cyano-1,2-dihydroquinoxalin-2-one (6.6 g) was heated at 110° C. for 1 hour with polyphosphoric acid (25 g). The mixture was diluted with water and extracted with chloroform. Evaporation of the solvent and recrystallisation of the residue from ethanol gave the title compound (3.8 g) mp 293°-297° (decomp).

1. extractionextracted with chloroform
2. customEvaporation of the solvent and recrystallisation of the residue from ethanol