反应详情

42 ml of diisobutylaluminum hydride (as a 1.5M solution in toluene) were added dropwise at a temperature between -20° C. and -15° C. to a solution of 16.0 g of dimethyl 1-[(2'-t-butoxycarbonylbiphenyl-4-yl)methyl]-2-butylimidazole-4,5-dicarboxylate [prepared as described in step (a) above] in 200 ml of tetrahydrofuran, and the resulting mixture was allowed to stand at 0°-5° C. for 16 hours. At the end of this time, the reaction mixture was mixed with an aqueous solution of ammonium chloride and ethyl acetate and was then stirred for 1 hour. After this, precipitates were removed by filtration. The ethyl acetate layer was then separated and dried over anhydrous magnesium sulfate, and the solvent was removed by distillation under reduced pressure. The residue was then purified by column chromatography through silica gel, using ethyl acetate as the eluent, to give 12.0 g of the title compound as crystals, melting at 99° C.

1. customAfter this, precipitates
2. customwere removed by filtration
3. customThe ethyl acetate layer was then separated
4. dry with materialdried over anhydrous magnesium sulfate
5. customthe solvent was removed by distillation under reduced pressure
6. customThe residue was then purified by column chromatography through silica gel