Реакция #358973

Уравнение реакции

2-methyl-3,5,6,7-tetrahydro-s-indacen-1(2H)-one

aluminum trichloride

bromine

→

red oil

Выход 120.2%

4-bromo-2-methyl-3,5,6,7-tetrahydro-s-indacen-1(2H)-one

Выход 120.2%

Растворители

chloroform

chloroform

Условия реакции

Обработка

1. 1
   workup.STIRRINGAfter stirring for one hour
2. 2
   ДругоеThe organic phase was separated off
3. 3
   Промывкаwashed with 5% strength sodium hydrogencarbonate solution and water
4. 4
   Сушкаsubsequently dried over magnesium sulfate
5. 5
   ФильтрацияFiltration and removal of the solvent under reduced pressure

Методика

31 g (162 mmol) of 2-methyl-3,5,6,7-tetrahydro-s-indacen-1(2H)-one (1a) were added to a suspension of 50 g (0.37 mol) of anhydrous aluminum trichloride in 200 ml of chloroform while stirring vigorously at 0° C. After stirring for one hour, a solution of 8 ml (160 mmol) of bromine in 20 ml of chloroform was added dropwise to the mixture at 0° C. and the mixture was subsequently stirred overnight. The reaction mixture was poured into 500 g of an ice/water mixture. The organic phase was separated off, washed with 5% strength sodium hydrogencarbonate solution and water and subsequently dried over magnesium sulfate. Filtration and removal of the solvent under reduced pressure gave 51 g of a red oil. GC-MS analysis indicated that the oil contained 84% of the desired compound (1b) and 14% of a dibromide by-product. The mixture was separated by column chromatography on silica gel using methylene chloride as eluant. This gave 18.7 g (44% yield) of the compound (1b).

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