反应详情

n-Butyllithium (2.4M solution in hexane; 92.7 mL, 0.222 mol) was added dropwise (20 min) to a solution of p-dibromobenzene (50.0 g, 0.212 mol) in Et2O (1.2 L) at -60° C. After completion of the addition, the reaction was left at -50° C. for 30 min and hexafluoroacetone (42.2 g, 0.254 mol) was bubbled through the heterogeneous mixture, at the same temperature. The resulting solution was allowed to warm to -30° C. over 30 min before saturated aqueous NH4Cl was added. The aqueous layer was extracted with EtOAc (2×) and the combined organic extracts were successively washed with 25% aqueous NH4OAc buffer, water and brine, dried (MgSO4) and concentrated. The residue was distilled under reduced pressure (bp 85°-90° C./12 mmHg) to afford the title compound as colorless crystals (53.5 g, 78%).

1. additionAfter completion of the addition
2. additionwas added
3. extractionThe aqueous layer was extracted with EtOAc (2×)
4. washthe combined organic extracts were successively washed with 25% aqueous NH4OAc buffer, water and brine
5. dry with materialdried (MgSO4)
6. concentrationconcentrated
7. distillationThe residue was distilled under reduced pressure (bp 85°-90° C./12 mmHg)