反应详情

A twelve-liter three neck flask fitted with an efficient mechanical stirrer, 250 mL dropping funnel, and internal thermometer was charged with glacial acetic acid (5000 mL), pyridinium bromide perbromide (90%, 830 g, 2.60 mol) and 30% hydrobromic acid in acetic acid (525 mL). After stirring at room temperature for ninety minutes, 4-acetylpyridine (250 g, 2.07 mol) was added dropwise over forty-five minutes. Upon completion of the addition the reaction mixture was cooled with an ice bath to 15° C. and the product, which had precipitated, was collected by filtration, washed with ether and air-dried. The crude α-bromo-4-acetylpyridine hydrobromide (566.3 g, 97%) was sufficiently pure for subsequent reactions, mp. 177.5°-182.0° C.

1. customA twelve-liter three neck flask fitted with an efficient mechanical stirrer
2. additionUpon completion of the addition the reaction mixture
3. temperaturewas cooled with an ice bath to 15° C.
4. customthe product, which had precipitated
5. filtrationwas collected by filtration
6. washwashed with ether
7. customair-dried