Reaktion #704881

Reaktionsgleichung

title compound

5,8-dichloro-2,3-dihydro-4H-1-benzothiopyran-4-one

aluminum chloride

hydrochloric acid

bromine

→

title compound

Ausbeute 96.8%

6-bromo-5,8-dichloro-2,3-dihydro-4H-1-benzothiopyran-4-one

Ausbeute 96.8%

Lösungsmittel

methylene chloride

methylene chloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture was refluxed for 10 min
2. 2
   TemperaturThe mixture, while still warm
3. 3
   Extraktionthe resulting mixture was extracted with diethyl ether (2×500 mL)
4. 4
   TrocknenThe combined organic layers were dried (Na2SO4)
5. 5
   Filtrationfiltered
6. 6
   Sonstigeevaporated to dryness

Vorschrift

A solution of 45.18 g (0.19 mol) of the title compound of Step B in 400 mL of methylene chloride was added dropwise at room temperature under nitrogen to a mixture of 64.6 g (0.48 mol) of aluminum chloride in 400 mL of methylene chloride. After stirring for 15 min, 10.5 mL (0.20 mol) of bromine was added dropwise and the mixture was refluxed for 10 min. The mixture, while still warm, was poured into 550 g of ice containing 110 mL of concentrated hydrochloric acid, and the resulting mixture was extracted with diethyl ether (2×500 mL). The combined organic layers were dried (Na2SO4), filtered, and evaporated to dryness to yield 57.37 g of the title compound of Step C as a solid melting at 89-90° C. 1H NMR (CDCl3): δ3.0 (m,2H), 3.3 (m,2H), 7.7 (s,1H).

Quelle