Hydrogen Peroxide → 3-Bromo-5-chlorobenzene-1,2-diol

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Reaction Steps

To a stirred suspension of 3-bromo-5-chloro-2-hydroxybenzaldehyde (49.5 g, 0.21 mol) in 0.5N aqueous NaOH (500 ml, 0.25 mol) at 40° C. was added dropwise hydrogen peroxide (21.4 g of a 35% aqueous solution, 0.22 mol) over 15 minutes and the resultant mixture stirred for 16 hours. The mixture was cooled to room temperature, diluted with 1 N aqueous NaOH (200 ml) and washed with diethyl ether (3×300 ml). The aqueous layer was acidified with concentrated HCl to pH 2 and extracted with Et2O (3×200 ml). The organic extracts were combined, washed with brine, dried (Na2SO4), filtered and concentrated in vacuo to afford the desired product as a red/brown solid (46.0 g, 99%).

Provenance & Evidence