反应详情

Into a solution of LDA in THF (20 mL, 12 mmol) was added a solution of tert-butyl 2,4-difluoronicotinate (2.14 g, 10 mmol) in THF (12 mL) at −78° C. The mixture was stirred for 30 min and then a solution of hexachloroethane (2.96 g, 12.5 mmol) in THF (7.0 mL) was added. The temperature was allowed to rise to 0° C. The reaction was then quenched with saturated NH4Cl. The mixture was extracted with ethyl acetate and the organic layers were combined, dried over sodium sulfate, evaporated and purified by silica chromatography (0-8% ethyl acetate in hexanes) to give tert-butyl 5-chloro-2,4-difluoronicotinate (1.2 g, 48%).

1. customto rise to 0° C
2. customThe reaction was then quenched with saturated NH4Cl
3. extractionThe mixture was extracted with ethyl acetate
4. dry with materialdried over sodium sulfate
5. customevaporated
6. custompurified by silica chromatography (0-8% ethyl acetate in hexanes)