反应详情

To a slightly tan, homogeneous solution of benzyl 3-cyano-2-fluorophenylcarbamate (4.45 g, 16.47 mmol) in THF (211 mL) in a −78° C. bath under nitrogen was syringed DIBAL-H (65.9 mL, 65.9 mmol)/CH2Cl2 dropwise over 75 min. The reaction was stirred for 30 min. The cold bath was removed, and the reaction was stirred to room temperature. After 4 hr, the solution was added to ice-cold water (300 mL) over 50 minutes; heavy emulsion ensued. After stirring for another 30 min, the organic layer was separated, and the aqueous layer/emulsion was filtered, and the insoluble materials were rinsed with CH2Cl2 (200 mL). The organic layers were combined and concentrated in vacuo. The residue was dissolved in CH2Cl2 (300 mL) and washed with brine (75 mL), dried over MgSO4, and concentrated in vacuo to give the desired product (4.0253 g, 11.78 mmol, 71.6% yield) as a tan solid.

1. customThe cold bath was removed
2. stirringthe reaction was stirred to room temperature
3. waitAfter 4 hr
4. additionthe solution was added to ice-cold water (300 mL) over 50 minutes
5. stirringAfter stirring for another 30 min
6. customthe organic layer was separated
7. filtrationthe aqueous layer/emulsion was filtered
8. washthe insoluble materials were rinsed with CH2Cl2 (200 mL)
9. concentrationconcentrated in vacuo
10. dissolutionThe residue was dissolved in CH2Cl2 (300 mL)
11. washwashed with brine (75 mL)
12. dry with materialdried over MgSO4
13. concentrationconcentrated in vacuo