反应详情

To a suspension of 2,6-dibromopyridine (2.37 g, 10 mmol) in THF (25 mL) at -70° there was added slowly n-BuLi, 1.4M, in hexane (7.9mL, 11 mmol). The resulting mixture was stirred in the cold until a solution was obtained (10 min). This solution was cannulated into a solution of hexafluoroacetone prepared by bubbling hexafluoroacetone into THF (10 mL) at -70° for 3 min. The resulting reaction mixture was stirred for 15 min., then quenched with an aqueous solution of NH4Cl (8 mL). The suspension was allowed to warm to r.t. and was extracted with Et2O. After drying and evaporation of the organic extract, the residue was chromatographed on silica gel with hexane:EtOAc, followed by bulb-to-bulb distillation to afford the title compound, m.p. 67°-69° C.

1. customwas obtained (10 min)
2. customprepared
3. customby bubbling hexafluoroacetone into THF (10 mL) at -70° for 3 min
4. customThe resulting reaction mixture
5. stirringwas stirred for 15 min.
6. customquenched with an aqueous solution of NH4Cl (8 mL)
7. extractionwas extracted with Et2O
8. customAfter drying
9. customevaporation of the organic extract
10. customthe residue was chromatographed on silica gel with hexane
11. distillationEtOAc, followed by bulb-to-bulb distillation