Sodium Hydroxide → 4-Bromo-2-ethylpyridine

Temperature

0 °C

4-Amino-2-ethylpyridine (18 g) was dissolved with warming in 48 ml of 48% hydrogen bromide. The solution was cooled to 0° C. and 15 ml of bromine was added dropwise followed by a solution of 25.4 g of sodium nitrite in 37 ml of water over 1/2 hour while maintaining the temperature below 5° C. The mixture was allowed to warm to room temperature over 2 hours and was then poured onto ice and made alkaline with 35% sodium hydroxide. The aqueous mixture was extracted three times with 200 ml of methylene chloride, the extract was concentrated and the residue was taken up in diethyl ether. The ether solution was dried over magnesium sulfate and concentrated in vacuo at below 40° C. to give, after chromatography (silica gel; 70:30 hexane-ether), 4.1 g of the title compound as an orange oil.

1. temperaturewhile maintaining the temperature below 5° C
2. temperatureto warm to room temperature over 2 hours
3. additionwas then poured onto ice
4. extractionThe aqueous mixture was extracted three times with 200 ml of methylene chloride
5. concentrationthe extract was concentrated
6. dry with materialThe ether solution was dried over magnesium sulfate
7. concentrationconcentrated in vacuo at below 40° C.
8. customto give

ORD record

ord-844fbe6845c048cbb74b312cfd9be32a

Source dataset

uspto-grants-1994_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05308843