反应详情

68 mg of sodium borohydride were added to a solution of 718 mg of 4-acetyl-2-butyl-1-[(2'-carboxybiphenyl-4-yl)methyl]-5-cyanoimidazole [prepared as described in step (b) above] in a mixture of 20 ml of isopropanol and 10 ml of ethanol, and the resulting mixture was stirred at room temperature for 3 hours. At the end of this time, the pH of the reaction mixture was adjusted to a value of 3 by the addition of 1N aqueous hydrochloric acid, after which the solvent was distilled off under reduced pressure. The resulting residue was mixed with methylene chloride and water, and the methylene chloride layer was separated. The aqueous layer was extracted three times with methylene chloride, and the combined extracts were dried and concentrated by evaporation under reduced pressure. The resulting residue was dissolved in 10 ml of ethyl acetate and allowed to stand at room temperature. The solid which then deposited was collected by filtration and dried, to give 398 mg of the title compound as a colorless powder, melting at 200°-201° C.

1. distillationafter which the solvent was distilled off under reduced pressure
2. additionThe resulting residue was mixed with methylene chloride and water
3. customthe methylene chloride layer was separated
4. extractionThe aqueous layer was extracted three times with methylene chloride
5. customthe combined extracts were dried
6. concentrationconcentrated by evaporation under reduced pressure
7. dissolutionThe resulting residue was dissolved in 10 ml of ethyl acetate
8. customto stand at room temperature
9. filtrationThe solid which then deposited was collected by filtration
10. customdried