反应详情

Under an argon atmosphere, a solution of cerium chloride (7.69 g, 3.0 equivalents) in THF (25 mL) was stirred at room temperature (25° C.) for 30 min. Sodium borohydride (1.22 g, 3.1 equivalents) was added, and the mixture was stirred at room temperature for 1 hr. Then bis(4-dimethylaminophenyl)phosphine oxide (3.0 g, 10.4 mmoL) synthesized in Reference Example 4 and lithium aluminum hydride (0.47 g, 1.2 equivalents) were successively added at 5° C., and the mixture was stirred at room temperature for 3 hrs. Water (20 mL) was added at 3° C. and then toluene (40 mL) and 6M—HCl (10 mL) were added. The mixture was stirred at room temperature for 30 min. The reaction mixture was neutralized with NaOH and partitioned. The aqueous layer was extracted with THF (50 mL). The combined organic layer was washed successively with 5% aqueous NaCl solution (20 mL). The organic layer was dried over anhydrous magnesium sulfate, filtered by gravity, and the filtrate was concentrated under reduced pressure. The residue was purified by column chromatography (silica gel 5 g, n-hexane/ethyl acetate=1/1). The residue was recrystallized from heptane to give the title compound (0.61 g, white crystals). yield 20.5%. melting point: 142.6° C.

1. additionwere successively added at 5° C.
2. stirringthe mixture was stirred at room temperature for 3 hrs
3. stirringThe mixture was stirred at room temperature for 30 min
4. custompartitioned
5. extractionThe aqueous layer was extracted with THF (50 mL)
6. washThe combined organic layer was washed successively with 5% aqueous NaCl solution (20 mL)
7. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
8. filtrationfiltered by gravity
9. concentrationthe filtrate was concentrated under reduced pressure
10. customThe residue was purified by column chromatography (silica gel 5 g, n-hexane/ethyl acetate=1/1)
11. customThe residue was recrystallized from heptane