反应详情

To a solution of methyl 2(R/S)-[4-(4-fluorophenoxy)benzenesulfonyl][(ethoxycarbonyl)methyl]amino-3,3-dimethyl-butanedioic acid (2.00 g, 3.91 mmol) and triethylamine (0.6 mL, 4.30 mmol) in 50 mL of benzene at 80° C. was added diphenylphosphoryl azide (0.93 mL, 4.3 mmol). After 4 hours, benzyl alcohol (1.62 mL, 15.6 mmol) was added. After an additional 20 hours, the reaction was cooled to room temperature and partitioned between ethyl acetate and 10% aq. citric acid. The organic layer was washed with sat. aq. sodium bicarbonate, dried over sodium sulfate, and concentrated. The excess benzyl alcohol was removed by kugelrohr distillation at 0.28 torr, 70° C., and the residue was purified by chromatography on silica, eluting with 30% ethyl acetate in hexane, to give methyl 2(R/S)-[4-(4-fluorophenoxy)benzenesulfonyl][(ethoxycarbonyl)methyl]amino-3-(benzyloxycarbonyl)amino-3-methylbutanoate (1.81 g, 75%) as a colorless, viscous oil.

1. waitAfter an additional 20 hours
2. custompartitioned between ethyl acetate and 10% aq. citric acid
3. washThe organic layer was washed with sat. aq. sodium bicarbonate
4. dry with materialdried over sodium sulfate
5. concentrationconcentrated
6. customThe excess benzyl alcohol was removed by kugelrohr distillation at 0.28 torr, 70° C.
7. customthe residue was purified by chromatography on silica
8. washeluting with 30% ethyl acetate in hexane