反应详情

温度

50 °C

A solution of (1,2-dimethyl-1H-imidazol-5-yl)(phenyl)methanone (8.41 g, 42 mmol) and hydroxylamine hydrochloride (7.30 g, 105 mmol) in pyridine (60 mL) was stirred for 5 h at room temperature, and for 3 h at 50° C. Hydroxylamine hydrochloride (3.00 g, 43 mmol) was added again and the reaction mixture was stirred for 9.5 h at 50° C. After removal of the solvent in vacuo and addition of water (600 mL), the pH of the aqueous solution was adjusted to pH>7 by addition of aq. NaOH (1 M). After extraction with ethyl acetate (4×150 mL), the combined organic layers were washed with water (150 mL), dried over MgSO4 and concentrated in vacuo. Purification on silica gel afforded 1-(1,2-dimethyl-1H-imidazol-5-yl)-N-hydroxy-1-phenylmethanimine [2.31 g, yield 24%; HPLC/MS: m/z=216 (M+H); log P(HCOOH)=0.43].

1. customAfter removal of the solvent
2. additionin vacuo and addition of water (600 mL)
3. additionthe pH of the aqueous solution was adjusted to pH>7 by addition of aq. NaOH (1 M)
4. extractionAfter extraction with ethyl acetate (4×150 mL)
5. washthe combined organic layers were washed with water (150 mL)
6. dry with materialdried over MgSO4
7. concentrationconcentrated in vacuo
8. customPurification on silica gel