反应详情

(+)-2-(tert-Butyl-dimethyl-silanyl)-4-[1-(2,3-difluoro-phenyl)-ethyl]-imidazole-1-sulfonic acid dimethylamide (350 mg, 0.81 mmol) was dissolved in 10 ml 1.5N hydrochloric acid and refluxed for 1 h. The cooled solution was adjusted to pH>8 with 25% aqueous ammonia and the solution was extracted with dichloromethane (2 times). The combined organic layers are dried over MgSO4, filtered and concentrated. The residue was purified by flash chromatography (silica gel, dichloromethane/methanol/aqueous conc. ammonia=90:10:1) to yield 80 mg (47%) of 4-[1-(2,3-difluoro-phenyl)-ethyl]-1H-imidazole (Enantiomer 1) as off-white solid: MS (ISP): 208.9 ((M+H)+.), chiral HPLC (Reprosil Chiral-NR; heptane/ethanol=90:10): tR=9.9 min. 4-[1-(2,3-Difluoro-phenyl)-ethyl]-1H-imidazole (Enantiomer 2) was obtained by the same procedure from (−)-2-(tert-butyl-dimethyl-silanyl)-4-[1-(2,3-difluoro-phenyl)-ethyl]-imidazole-1-sulfonic acid dimethylamide in 73% yield; colourless oil, MS (ISP): 208.9 ((M+H)+.), chiral HPLC (Reprosil Chiral-NR; heptane/ethanol=90:10): tR=11.1 min.

1. temperaturerefluxed for 1 h
2. extractionthe solution was extracted with dichloromethane (2 times)
3. dry with materialThe combined organic layers are dried over MgSO4
4. filtrationfiltered
5. concentrationconcentrated
6. customThe residue was purified by flash chromatography (silica gel, dichloromethane/methanol/aqueous conc. ammonia=90:10:1)