反应详情

1-(3,4-Dichlorophenyl)-2-pyridin-4-yl-ethane-1,2-dione (2.8 g, 10 mmol), 4-formylpiperidine-1-carboxylic acid benzyl ester (2.47 g, 10 mmol) and ammonium acetate (7.7 g, 100 mmol) were dissolved in acetic acid (65 mL) and heated to reflux for 2.5 hour and allowed to cool to ambient temperature. The reaction mixture was then poured over an ammonium hydroxide (100 mL) and ice mixture. This aqueous layer was extracted with ethyl acetate (3×200 mL) and the organic layers were combined, washed with brine (100 mL), dried over anhydrous magnesium sulfate, filtered and concentrated at reduced pressure. The resulting oil was chromatographed on silica gel eluting with 97:3 dichloromethane:methanol to give the imidazole as a foam (2.3 g).

1. temperatureheated
2. temperatureto reflux for 2.5 hour
3. extractionThis aqueous layer was extracted with ethyl acetate (3×200 mL)
4. washwashed with brine (100 mL)
5. dry with materialdried over anhydrous magnesium sulfate
6. filtrationfiltered
7. concentrationconcentrated at reduced pressure
8. customThe resulting oil was chromatographed on silica gel eluting with 97:3 dichloromethane