반응 #51456

반응 방정식

benzyl alcohol

methyl 2(R/S)-[4-(4-fluorophenoxy)benzenesulfonyl][(ethoxycarbonyl)methyl]amino-3,3-dimethyl-butanedioic acid

triethylamine

diphenylphosphoryl azide

→

methyl 2(R/S)-[4-(4-fluorophenoxy)benzenesulfonyl][(ethoxycarbonyl)methyl]amino-3-(benzyloxycarbonyl)amino-3-methylbutanoate

수율 75.1%

용매

benzene

반응 조건

후처리

1. 1
   workup.WAITAfter an additional 20 hours
2. 2
   기타partitioned between ethyl acetate and 10% aq. citric acid
3. 3
   세척The organic layer was washed with sat. aq. sodium bicarbonate
4. 4
   건조dried over sodium sulfate
5. 5
   농축concentrated
6. 6
   기타The excess benzyl alcohol was removed by kugelrohr distillation at 0.28 torr, 70° C.
7. 7
   기타the residue was purified by chromatography on silica
8. 8
   세척eluting with 30% ethyl acetate in hexane

실험 절차

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.

출처