Hydrogen Bromide → 2-Bromo-5-chloro-2,3-dihydro-1H-inden-1-one

Beteiligte Stoffe

Reaktionsschritte

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.

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