Réaction #4440

Équation de réaction

hydrobromic acid

4-acetylpyridine

→

α-Bromo-4-acetylpyridine hydrobromide

Solvants

acetic acid

acetic acid

Conditions de réaction

Traitement

1. 1
   AutreA twelve-liter three neck flask fitted with an efficient mechanical stirrer
2. 2
   workup.ADDITIONUpon completion of the addition the reaction mixture
3. 3
   Températurewas cooled with an ice bath to 15° C.
4. 4
   Autrethe product, which had precipitated
5. 5
   Filtrationwas collected by filtration
6. 6
   Lavagewashed with ether
7. 7
   Autreair-dried

Mode opératoire

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.

Source