Boron tribromide → 2-Bromo-1-(3,4-dihydroxy-5-nitro-phenyl)-ethanone

Beteiligte Stoffe

Reaktionsschritte

A suspension of 29.0 g of 2-bromo-4'-hydroxy-3'-methoxy-5'-nitroacetophenone in 700 ml of dry methylene chloride is treated at -20° within 30 minutes with a solution of 125.3 g of boron tribromide in 300 ml of dry methylene chloride. After the addition the mixture is stirred at -20° for a further 1 hour and at room temperature for 16 hours, then evaporated, the residue is treated cautiously with water while cooling with ice and stirred at 50° for 30 minutes. After cooling the mixture is extracted with ether, the ethereal phase is washed with water, dried over sodium sulfate, filtered and evaporated. There is obtained 2-bromo-3',4'-dihydroxy-5'-nitroacetophenone of m.p. 138°-140° (from methylene chloride).

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