Boron tribromide → 3-Chloro-4,5-dihydroxybenzaldehyde

Beteiligte Stoffe

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Reaktionsschritte

37.2 g of commercial 5-chloro vanillin and 800 ml of dichloromethane were mixed together under nitrogen and cooled to 0° C. 300 ml of a molar solution of boron tribromide in dichloromethane are added and the mixture stood for one night at ambient temperature. It was concentrated, cooled again to 0° C. and acidified. The crystallized product was separated, washed with water, dried and crystallized from an isopropanol- water mixture (1-2 by volume) to obtain 26.6 g of the expected product melting at >260° C.

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