反应详情

温度

-78 °C

In a round bottom flask (2,4-difluoro-phenyl)-carbamic acid benzyl ester (30, 3.83 g, 14.5 mmol) is combined with 148 mL of tetrahydrofuran. The solution is chilled to −78° C. and n-butyllithium (19.1 mL, 1.60 M in hexane, 30.0 mmol) is added over 30 minutes, followed by the addition of N,N-dimethylformamide (1.12 mL, 14.5 mol). The reaction mixture is allowed to warm to ambient temperature and is stirred overnight, then poured into water and extracted with ethyl acetate. The organic layer is washed with brine, dried over sodium sulfate, filtered and the filtrate concentrated under vacuum. The resulting material is crystallized from ether to provide the desired compound (33, 3.0 g, 71%).

1. temperatureto warm to ambient temperature
2. extractionextracted with ethyl acetate
3. washThe organic layer is washed with brine
4. dry with materialdried over sodium sulfate
5. filtrationfiltered
6. concentrationthe filtrate concentrated under vacuum
7. customThe resulting material is crystallized from ether