تفاعل #74904

معادلة التفاعل

NaHSO3

5-chloro-1-indanone

hydrobromic acid

bromine

→

2-Bromo-5-chloro-1-indanone

المذيبات

water

acetic acid

acetic acid

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONhas been added
2. 2
   workup.ADDITIONhave been added
3. 3
   أخرىThe product, which initially precipitates in the viscous form
4. 4
   workup.STIRRINGafter stirring for a relatively long time
5. 5
   ترشيحThe crude product is filtered off (melting point 69°-76° C.)
6. 6
   غسيلwashed with water
7. 7
   أخرىrecrystallized from petroleum ether

الإجراء التجريبي

A solution of 37.9 g (0.237 mole) of bromine in 120 ml of glacial acetic acid is slowly added dropwise, whilst stirring, to a solution of 40.0 g (0.237 mole) of 5-chloro-1-indanone in 590 ml of glacial acetic acid, to which 0.2 ml of 48% strength aqueous hydrobromic acid has been added. The mixture is stirred for a further 2 hours and the reaction solution is poured into 1 l of water, to which 2.5 g of NaHSO3 have been added. The product, which initially precipitates in the viscous form, becomes crystalline after stirring for a relatively long time. The crude product is filtered off (melting point 69°-76° C.), washed with water and recrystallized from petroleum ether. The pure 2-bromo-5-chloro-1-indanone melts at 89°-90° C.

المصدر