[CH:1]1[C:9]2[C:8]3[CH:10]=[CH:11][CH:12]=[CH:13][C:7]=3[O:6][C:5]=2[CH:4]=[CH:3][CH:2]=1.[N+:14]([O-])([OH:16])=[O:15]>FC(F)(F)C(O)=O>[N+:14]([C:3]1[CH:2]=[CH:1][C:9]2[C:8]3[CH:10]=[CH:11][CH:12]=[CH:13][C:7]=3[O:6][C:5]=2[CH:4]=1)([O-:16])=[O:15]To 80 mL trifluoroacetic acid in a 250 mL round bottom flask was added dibenzofuran (7.06 g, 42 mmol) and stirred vigorously to dissolve the content at room temperature. The solution was then cooled on ice and 1.2 equivalent 70% HNO3 (4.54 g, 50.40 mmol) in 20 mL trifluoroacetic acid was poured into the stirred solution slowly. After stirring for 30 minutes contents from the flask was poured into 150 mL ice-water and stirred for another 15 minutes. Off white color precipitate was then filtered out and finally washed with 2M NaOH and water. Moist material was then recrystallized from 1.5 L boiling ethanol in the form of light yellow color crystal. 7.2 g of product was isolated.
Loading…