反应详情

To 4.20 g (19.6 mmol) of 4-phenylsulfanyl-benzaldehyde, 1.50 g (21.6 mmol) of H2NOH—HCl and 2.71 g (33.1 mmol) of sodium acetate are added 6.5 mL of H2O and 19.5 mL of ethanol. This reaction mixture is heated to reflux for 2 h. After adding H2O to dissolve the precipitated inorganic salt, ethanol is removed by evaporation in vacuo. The crude product is extracted twice with CH2Cl2. The CH2Cl2 layer is dried over anhydrous MgSO4 and then condensed. The residue is applied to column chromatography on silica gel with CH2Cl2 and CH2Cl2-acetone (10:1) as eluent. 3.86 g of white solid are obtained as the first fraction (86%). This product is assigned to be (E) oxime by 1H-NMR spectrum (CDCl3). δ [ppm]: 7.25 (d, 2H), 7.32-7.35 (m, 3H), 7.42 (d, 2H), 7.47 (d, 2H), 7.77 (s, 1H), 8.09 (s, 1H); 0.29 g of white solid are obtained as the second fraction (6.6%). This product is assigned to be (Z) oxime by 1H-NMR spectrum (CDCl3). δ [ppm]: 7.25 (d, 2H), 7.32-7.38 (m, 4H), 7.45 (d, 2H), 7.84 (d, 2H). 9.55 (broad s, 1H)

1. temperatureThis reaction mixture is heated
2. temperatureto reflux for 2 h
3. customis removed by evaporation in vacuo
4. extractionThe crude product is extracted twice with CH2Cl2
5. dry with materialThe CH2Cl2 layer is dried over anhydrous MgSO4
6. customcondensed