反应详情

温度

80 °C

4-[5-(3,4-Dichlorophenyl)-4-pyridin-4-yl-1H-imidazol-2-yl]piperidine-1-carboxylic acid benzyl ester (3.8 g, 7.5 mmol) dissolved in hydrogen bromide (30 wt. %) in acetic acid (20 mL) was heated to 80° C. for one hour, after which time the reaction mixture was allowed to cool to ambient temperature and concentrated at reduced pressure. The residue was then dissolved in hydrochloric acid (100 mL of 1N) and extracted with ethyl acetate (100 mL). The aqueous layer was then basified with sodium hydroxide (35 mL of 3N) and buffered with saturated aqueous sodium hydrogen carbonate (300 mL). The aqueous layer was extracted with chloroform (5×200 mL) and the organic layers combined, dried over anhydrous sodium sulfate, filtered and concentrated at reduced pressure. The resulting foam was crystallized from ethyl acetate/hexane to give the free amine (2.2 g).

1. temperatureto cool to ambient temperature
2. concentrationconcentrated at reduced pressure
3. dissolutionThe residue was then dissolved in hydrochloric acid (100 mL of 1N)
4. extractionextracted with ethyl acetate (100 mL)
5. extractionThe aqueous layer was extracted with chloroform (5×200 mL)
6. dry with materialdried over anhydrous sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated at reduced pressure
9. customThe resulting foam was crystallized from ethyl acetate/hexane