反应详情

To a stirred solution of 2a (423 g., 2.68 moles) in anhydrous ether (1 L) was added dropwise in 1 hour a freshly prepared solution of n-butyllithium (27 moles) in ether keeping a gentle reflux under dry N2. Reflux being continued for 0.5 hour, a solution of DMF (dimethylformamide) (432 g., 6 moles) in anhydrous ether (0.8 L) was added dropwise to the mixture over a period of 0.75 hour with vigorous stirring. After the complete addition the mixture was stirred overnight, poured onto crushed ice (1 Kg.) with stirring and allowed to rise to room temperature. The organic layer was separated and the water layer was saturated with NaCl and extracted thoroughly with ether (2 × 200 ml.). The ether extracts were combined, dried over MgSO4 and concentrated. The residue was distilled under reduced pressure and the pale yellow oil was collected at 100°-125° C., 0.7 mmHg. Yield, 277 g. (56%).

1. temperaturea gentle reflux under dry N2
2. temperatureReflux
3. additionAfter the complete addition the mixture
4. additionpoured
5. stirringwith stirring
6. customto rise to room temperature
7. customThe organic layer was separated
8. extractionextracted thoroughly with ether (2 × 200 ml.)
9. dry with materialdried over MgSO4
10. concentrationconcentrated
11. distillationThe residue was distilled under reduced pressure
12. customthe pale yellow oil was collected at 100°-125° C.
13. customYield