Reaktion #2045089

Reaktionsgleichung

Bromine

1-(6-chloro-pyridin-3-yl)-propan-1-one

hydrobromic acid

→

2-bromo-1-(6-chloro-pyridin-3-yl)-propan-1-one

Lösungsmittel

acetic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeis formed
2. 2
   Temperaturcooled down to 10° C.
3. 3
   Filtrationfiltered
4. 4
   WaschenThe solid remainder is washed with tert-butyl methyl ether
5. 5
   workup.ADDITIONTo a suspension of this intermediate in 800 ml of tert-butyl methyl ether
6. 6
   workup.ADDITIONis added 400 ml of a saturated aqueous sodium bicarbonate solution
7. 7
   workup.STIRRINGthe reaction mixture is stirred for 15 min
8. 8
   SonstigeThe phases are separated
9. 9
   Waschenthe organic layer is washed with brine
10. 10
    Trocknendried over sodium sulfate
11. 11
    Einengenconcentrated under reduced pressure

Vorschrift

Bromine (45.4 g) is slowly added to the mixture of 1-(6-chloro-pyridin-3-yl)-propan-1-one (48.2 g), 0.4 ml of hydrobromic acid (33% solution in acetic acid) and 250 ml of acetic acid at room temperature under a nitrogen atmosphere. Subsequently, the mixture is slowly heated to 80° C. The reaction mixture is stirred at 80° C. for 30 min, during which a yellow suspension is formed, then cooled down to 10° C. and filtered. The solid remainder is washed with tert-butyl methyl ether to deliver 2-bromo-1-(6-chloro-pyridin-3-yl)-propan-1-one hydrobromide as a yellowish solid. To a suspension of this intermediate in 800 ml of tert-butyl methyl ether is added 400 ml of a saturated aqueous sodium bicarbonate solution and the reaction mixture is stirred for 15 min. The phases are separated, the organic layer is washed with brine, dried over sodium sulfate and concentrated under reduced pressure to obtain 2-bromo-1-(6-chloro-pyridin-3-yl)-propan-1-one as an oil.

Quelle