反応 #2254182

反応方程式

Acetyl chloride

AlCl3

2-bromo-3-methylthiophene

→

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

収率 56.6%

溶媒

dichloromethane

反応条件

後処理

1. 1
   workup.WAITAfter 1 hour at 0° C.
2. 2
   その他the reaction is quenched
3. 3
   workup.ADDITIONby added water (100 ml)
4. 4
   抽出The mixture is extracted three times with dichloromethane
5. 5
   乾燥dried over MgSO4
6. 6
   濃縮concentrated in vacuo
7. 7
   その他The crude product is purified by chromatography on silica gel (180 g)
8. 8
   洗浄eluting with a mixture of ethyl acetate and heptane (1:6)

実験手順

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.

出典