تفاعل #51456

معادلة التفاعل

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

المردود 75.1%

المذيبات

benzene

ظروف التفاعل

المعالجة

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

الإجراء التجريبي

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.

المصدر