Réaction #2254182

Équation de réaction

Acetyl chloride

AlCl3

2-bromo-3-methylthiophene

→

1-(5-bromo-4-methyl-thiophen-2-yl)-ethanone

Rendement 56.6%

Solvants

dichloromethane

Conditions de réaction

Traitement

1. 1
   workup.WAITAfter 1 hour at 0° C.
2. 2
   Autrethe reaction is quenched
3. 3
   workup.ADDITIONby added water (100 ml)
4. 4
   ExtractionThe mixture is extracted three times with dichloromethane
5. 5
   Séchagedried over MgSO4
6. 6
   Concentrationconcentrated in vacuo
7. 7
   AutreThe crude product is purified by chromatography on silica gel (180 g)
8. 8
   Lavageeluting with a mixture of ethyl acetate and heptane (1:6)

Mode opératoire

Acetyl chloride (7.09 g) is added to a suspension of AlCl3 (11.53 g) in dichloromethane (310 ml) at 0° C. After 45 minutes at 0° C., 2-bromo-3-methylthiophene (5.0 g) is added dropwise. After 1 hour at 0° C., the reaction is quenched by added water (100 ml). The mixture is extracted three times with dichloromethane. The organic phases are combined, dried over MgSO4 and concentrated in vacuo. The crude product is purified by chromatography on silica gel (180 g) eluting with a mixture of ethyl acetate and heptane (1:6) to yield 1-(5-bromo-4-methyl-thiophen-2-yl)-ethanone (3.5 g) as a brown solid.

Source