4-Bromophenylglyoxal hydrate

Synthesis

SeO₂ (1390 mg, 1.25 mmol) was suspended in a mixture of 1,4-dioxane (6 mL) and H₂O (0.4 mL), and 4-bromophenylmethyl ketone (5.0 mmol) was added for microwave irradiation at a set temperature of 100°C for 15 minutes. The solution was then cooled to room temperature, filtered to remove Se, and washed with MeOH (20 mL). The combined organic filtrates were concentrated under reduced pressure, and the organic residue was stirred in boiling H₂O (35 mL) and hot filtered to remove any insoluble precipitates.

The aqueous filtrate was cooled on ice to obtain crystals of the arylglyoxal monohydrate product. These crystals were collected under vacuum filtration, washed with cold H₂O, and dried in a vacuum desiccator to give 4-bromophenylglyoxal hydrate, a white powder (82%).

Application

4-Bromophenyl hydrated glyoxal can be used as a pharmaceutical synthesis intermediate. It can be prepared by reacting 4-bromophenylmethyl ketone with selenium dioxide.