反应详情

Next, 1.09 g (2.01 mmol) of benzyl 2-(N-benzyloxycarbonylamino)-4-[methyl(3-nitrophenyl)phosphono]butanoate and 1.30 g (12.0 mmol) of anisole were dissolved in 10 mL of dry nitromethane and mixed with 0.80 g (6.00 mmol) of aluminum trichloride and reaction was carried out at room temperature for 3 hours. Thereafter, 20 mL of water was added and stirred for 10 minutes. The mixture was washed with 50 mL of ether three times and the water layer was removed, and methanol was added to adjust the final concentration of methanol to be 30%. The solution was passed through a short column of neutral silica gel 60N to remove aluminum hydroxide. Without being concentrated, 30 mL of the effluent was purified by medium pressure reversed-phase column chromatography ODS-S-50B. The column was eluted with a linear gradient of 30 to 60% methanol at a flow rate of 6 mL/min and the fractions containing the compound eluted at 60% methanol were collected. The elution and purity of the compound were confirmed by TLC (BuOH/AcOH/H2O=5:2:2, ninhydrin coloration). After vacuum concentration, freeze drying was carried out from water to obtain 2-amino-4-[methyl(3-nitrophenyl)phosphono]butanoic acid (0.40 g, yield 63%) as a colorless solid.

1. washThe mixture was washed with 50 mL of ether three times
2. customthe water layer was removed
3. additionmethanol was added
4. customto remove aluminum hydroxide
5. concentrationWithout being concentrated
6. custom30 mL of the effluent was purified by medium pressure reversed-phase column chromatography ODS-S-50B
7. washThe column was eluted with a linear gradient of 30 to 60% methanol at a flow rate of 6 mL/min
8. additionthe fractions containing the compound
9. washeluted at 60% methanol
10. customwere collected
11. washThe elution and purity of the compound
12. concentrationAfter vacuum concentration, freeze
13. customdrying