反应详情

温度

5 °C

817 mg of methyl (S)-2-amino-4,4-difluoro-5-phenylpentanoate (3.36 mmol) were dissolved in 20 ml of dichloromethane, admixed with 1.08 ml of pyridine (4 eq.) and cooled to approx. 5° C. (ice bath). After 10 min, 2.3 ml (1.3 eq.) of a 20% phosgene solution in toluene were added dropwise. The resulting suspension was stirred with ice bath cooling for 4 h and then concentrated under reduced pressure. The residue thus obtained was taken up in toluene and filtered. After the solvent had been removed under reduced pressure, methyl (S)-4,4-difluoro-2-isocyanato-5-phenylpentanoate was obtained as an orange oil which was used without further purification in the subsequent reaction. Yield: 943 mg (quant.)

1. temperaturecooling for 4 h
2. concentrationconcentrated under reduced pressure
3. customThe residue thus obtained
4. filtrationfiltered
5. customAfter the solvent had been removed under reduced pressure