反应详情

2.11 g (0.01 mol) of 2-chloro-5-(2,2,2-trifluoro-1-hydroxyethyl)pyridine and 0.18 g (0.0005 mol) of tetrabutylammonium hydrogen sulfate are dissolved in 25 ml of chlorobenzene at room temperature. 12 ml (0.02 mol) of an approximately 12% strength sodium hypochlorite solution are metered in within 10 minutes with vigorous stirring and the mixture is stirred for a further 4 hours during which the reaction temperature rises to 30° C. The reaction mixture is added to 50 ml of water, the phases are separated, the aqueous phase is extracted several times with methylene chloride and the combined organic phases are washed with saturated aqueous sodium chloride solution. After drying the organic phase with sodium sulfate, the volatiles are distilled off. Following distillation of the crude product in a kugelrohr (0.5 mbar, 100°-120° C. bath temperature), 1.41 g (67% of theory) of 2-chloro-5-trifluoroacetylpyridine are obtained, which, according to GC, is 98% pure.

1. customare metered in within 10 minutes
2. stirringthe mixture is stirred for a further 4 hours during which the reaction temperature
3. customrises to 30° C
4. customthe phases are separated
5. extractionthe aqueous phase is extracted several times with methylene chloride
6. washthe combined organic phases are washed with saturated aqueous sodium chloride solution
7. dry with materialAfter drying the organic phase with sodium sulfate
8. distillationthe volatiles are distilled off
9. distillationdistillation of the crude product in a kugelrohr (0.5 mbar, 100°-120° C. bath temperature), 1.41 g (67% of theory) of 2-chloro-5-trifluoroacetylpyridine
10. customare obtained