3-Hydroxybenzaldehyde → 2-Bromo-5-hydroxybenzaldehyde

Participants

Reaction Steps

To a solution 3-hydroxybenzaldehyde (Aldrich, 101.39 g, 805 mmol) in chloroform (1000 mL), was added bromine (45 mL, 845 mmol) in chloroform (200 mL) drop wise over a period of 2 h at room temperature. The reaction mixture was stirred at room temperature overnight and filtered to collect crude 2-bromo-5-hydroxy benzaldehyde (32 g) as a dark brown solid. The filtrate was concentrated to 200 mL, filtered through a pad of Celite and silica gel (40 g) and washed with ether (1000 mL). The filtrate was concentrated in vacuo to give a second crop of the crude desired aldehyde (60 g) as a dark brown solid. The above solids were combined and dissolved in glacial acetic acid (360 mL) by heating. Water (840 mL) was added and the solution was filtered hot. The solution was allowed to attain room temperature and kept in a refrigerator overnight. The crystals obtained were collected by filtration and washed with water, dried overnight in vacuo to furnish (60 g, 37%) of the desired product as a purplish brown crystalline solid, mp: 135° C.

Provenance & Evidence