[OH:1][N:2]1[C:7]([CH3:9])([CH3:8])[CH2:6][CH:5]([O:10][C:11]([CH:13]2[CH2:15][CH2:14]2)=[O:12])[CH2:4][C:3]1([CH3:17])[CH3:16].[ClH:18]>C(O)C>[ClH:18].[OH:1][N:2]1[C:7]([CH3:9])([CH3:8])[CH2:6][CH:5]([O:10][C:11]([CH:13]2[CH2:14][CH2:15]2)=[O:12])[CH2:4][C:3]1([CH3:17])[CH3:16]The nitroxide of Example 5a (2.2 g, 9.15 mmol) was added to a solution of saturated hydrogen chloride in ethanol (20 mL). The red color disappeared quickly and the resulting yellow colored solution was boiled to give clear colorless solution. The solution was concentrated in vacuo, dissolved in 100 mL ethyl acetate and was washed with saturated NaHCO3 to obtain the hydroxylamine free-base. The ethyl acetate layer was separated, acidified with ethereal HCl, and concentrated to give white solid, which was recrystallized from ethanol (10 mL) as a white crystalline solid 1.15 g (4.13 mmol, 45.1%). m.p. 224-228° C. (dec.).
読み込み中…