反应详情

10 ml of a 1.5M solution of diisobutylaluminum hydride in toluene were added dropwise at -20° C. under an atmosphere of nitrogen to a solution of 4.27 g of diethyl 2-propyl-1-{4-[2-(trityltetrazol-5-yl)phenyl]phenyl}methylimidazole-4,5-dicarboxylate [prepared as described in step (a) above] in 50 ml of tetrahydrofuran. The resulting mixture was allowed to stand at 0° C. for 16 hours and then mixed with ethyl acetate and with a saturated aqueous solution of ammonium chloride; it was then stirred at room temperature for 1 hour. The resulting precipitate was filtered off, and the ethyl acetate layer was separated and dried over anhydrous magnesium sulfate; the solvent was then removed by distillation under reduced pressure. The crystalline residue was washed with diisopropyl ether, to give 4.03 g of the title compound, melting at 135°-138° C.

1. filtrationThe resulting precipitate was filtered off
2. customthe ethyl acetate layer was separated
3. dry with materialdried over anhydrous magnesium sulfate
4. customthe solvent was then removed by distillation under reduced pressure
5. washThe crystalline residue was washed with diisopropyl ether