Hydrogen Bromide → 2-Bromo-4-(4-trifluoromethylphenyl)-1-indanone

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Reaction Steps

2.76 g (10 mmol) of 4-(4-trifluoromethylphenyl)-1-indanone are dissolved in 20 ml of glacial acetic acid and, after addition of 10 μl of a 48% strength solution of HBr in glacial acetic acid, while stirring a solution of 0.516 ml (10.05 mmol) of bromine in glacial acetic acid is added. After 3 h at room temperature, the reaction mixture is poured into a mixture of 100 ml of water with 100 g of ice and 100 mg of sodium bisulfite, and the resulting suspension is shaken with dichloromethane. The organic phase is washed 3× with water, dried over sodium sulfate, filtered and concentrated in vacuo. The residue is chromatographed on silica gel with dichloromethane/n-heptane 3/1. 2-Bromo-4-(4-trifluoromethylphenyl)-1-indanone is obtained with a melting point of 102-105° C., in addition to a little 2,2-dibromo compound.

Provenance & Evidence