反应详情

A solution of (1-methyl-1H-imidazol-5-yl)(3-thienyl)methanone (11.6 g, 60.0 mmol) and hydroxylamine hydrochloride (14.6 g, 210 mmol) in pyridine (60 mL) was stirred 9 h at 60° C. then left to stand for 72 h at room temperature. After removal of the solvent in vacuo, addition of water (200 mL), pH adjustment to approx 7 with aq. NaOH (1 M) induced precipitation of a solid. Filtration, sequential washings of the precipitate with water and heptane, and drying of the solid afforded a first crop of N-hydroxy-1-(1-methyl-1H-imidazol-5-yl)-1-(3-thienyl)methanimine. The combined aqueous phases were extracted with dichloromethane, the combined organic layers were dried over MgSO4 and concentrated in vacuo. The residue was purified recrystallized from heptane to afford a second crop of N-hydroxy-1-(1-methyl-1H-imidazol-5-yl)-1-(3-thienyl)methanimine. The crops were combined and recrystallized from diisopropylether to afford final N-hydroxy-1-(1-methyl-1H-imidazol-5-yl)-1-(3-thienyl)methanimine [9.95 g, yield 76%; HPLC/MS m/z=208 (M+H); log P(HCOOH)=0.21].

1. waitthen left
2. customAfter removal of the solvent
3. additionin vacuo, addition of water (200 mL), pH adjustment to approx 7 with aq. NaOH (1 M)
4. customprecipitation of a solid
5. filtrationFiltration, sequential washings of the precipitate with water and heptane
6. customdrying of the solid