C([NH:4][C:5]1[CH:14]=[C:13]2[C:8]([NH:9][C:10](=[O:22])[C:11](=[O:21])[N:12]2[CH:15]2[CH2:20][CH2:19][CH2:18][CH2:17][CH2:16]2)=[CH:7][CH:6]=1)(=O)C.[N+:23]([O-])([O-:25])=[O:24].[K+]>S(=O)(=O)(O)O>[NH2:4][C:5]1[CH:14]=[C:13]2[C:8]([NH:9][C:10](=[O:22])[C:11](=[O:21])[N:12]2[CH:15]2[CH2:20][CH2:19][CH2:18][CH2:17][CH2:16]2)=[CH:7][C:6]=1[N+:23]([O-:25])=[O:24]20.6 g (68 mmol) of 7-acetamido-1-cyclohexyl-2,3(1H,4H)-quinoxalinedione were dissolved in 250 ml of concentrated sulfuric acid. Then, at 0°-5° C., 7.2 g (71 mmol) of potassium nitrate were added a little at a time. The mixture was then stirred at 0° C. for 30 min and at room temperature for 2 h and subsequently poured into 1.5 1 of ice-water and then heated on a water bath for 4 h. The resulting precipitate was filtered off with suction. The filtrate was adjusted to pH 6 with a little ammonia solution and was extracted with methylene chloride. The organic phase was dried and concentrated under reduced pressure. This residue and the first precipitate were combined to yield 13.4 g (64%) of the product. Melting point >260° C.
読み込み中…