Chlorine → 5-Bromo-3-chloro-2-hydroxybenzaldehyde

Participants

Reaction Steps

To a 5 L round bottom flask fitted with a mechanical stirrer and gas addition tube was added 5-bromosalicylaldehyde (495 g, 2.46 mol) and acetic acid at ambient temperature to form a slurry. To this mixture was added chlorine gas at a moderate rate until a slight molar excess of chlorine (183 g, 1.05 mol) had dissolved. After the addition was stopped the reaction allowed to proceed overnight. The solid formed was recovered by filtration and the filtrate diluted into water (2.5 L). The mixture was stirred vigorously for 20 minutes, the product collected by filtration and washed with water. The combined solids were vacuum dried to give the desired 3-chloro-5-bromosalicylaldehyde (475 g, 82% yield).

Provenance & Evidence