Reacción #2254182

Ecuación de reacción

Acetyl chloride

AlCl3

2-bromo-3-methylthiophene

→

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

Rendimiento 56.6%

Disolventes

dichloromethane

Condiciones de reacción

Tratamiento posterior

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

Procedimiento

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.

Fuente