反应详情

温度

-15 °C

5-Fluoro-3-nitropyridine-2-amine (2.66 g) suspended in concentrated hydrochloric acid (35 ml) was cooled to −15° C., and an aqueous solution (7 ml) of sodium nitrite (2.57 g) was added dropwise over 10 minutes. After stirring at −10° C. for 1 hour, and further stirring at room temperature for 1 hour, under ice cooling a 30% aqueous sodium hydroxide solution was added for neutralization. The insolubles were collected by filtration, washed with water, air-dried, and then redissolved in ethyl acetate, before the insolubles were filtered off. The filtrate was concentrated under reduced pressure to afford 2-chloro-5-fluoro-3-nitropyridine (1.41 g).

1. additionwas added for neutralization
2. filtrationThe insolubles were collected by filtration
3. washwashed with water
4. customair-dried
5. dissolutionredissolved in ethyl acetate, before the insolubles
6. filtrationwere filtered off
7. concentrationThe filtrate was concentrated under reduced pressure