反应详情

(S)-3-t-Butoxycarbonyl-amino-4-(biphenyl-4-yl)-butyric acid methyl ester (716 mg, 2 mmol) is stirred for 1 hour in a 1/1 mixture of trifluoroacetic acid and methylene chloride (5 mL). Ethyl acetate (20 mL) is added and the solution is washed with saturated sodium bicarbonate (20 mL). The organic layer is separated, dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue is dissolved in methylene chloride (10 mL) and cooled to 0° under nitrogen. Diisopropyl ethylamine (0.42 mL, 2.4 mmol) is added, followed by a solution of dimethylphosphonomethyl trifluoromethylsulfonate (Tetrahedron Lett., 1986, 1477; 545 mg, 2.2 mmol). The mixture is stirred for 18 hours at room temperature. The solution is washed with saturated sodium bicarbonate, water and brine. The organic layer is dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue is purified by flash-chromatography to afford (S)-4-(biphenyl-4-yl)-3-[(dimethylphosphonomethyl)-amino]-butyric acid methyl ester as a white solid, m.p. 67°.

1. washthe solution is washed with saturated sodium bicarbonate (20 mL)
2. customThe organic layer is separated
3. dry with materialdried over anhydrous sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. dissolutionThe residue is dissolved in methylene chloride (10 mL)
7. temperaturecooled to 0° under nitrogen
8. washThe solution is washed with saturated sodium bicarbonate, water and brine
9. dry with materialThe organic layer is dried over anhydrous sodium sulfate
10. filtrationfiltered
11. concentrationconcentrated in vacuo
12. customThe residue is purified by flash-chromatography