Реакция #2254182

Уравнение реакции

Acetyl chloride

AlCl3

2-bromo-3-methylthiophene

→

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

Выход 56.6%

Растворители

dichloromethane

Условия реакции

Обработка

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

Методика

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.

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