74213-24-4

298-12-4

74213-24-4

General procedure for the synthesis of 1,1-dibromoformaldehyde oxime from 2-oxoacetic acid: hydroxylamine hydrochloride (10 mmol) was added to a stirred aqueous (50 mL) solution of glyoxalic acid (10 mmol), and the reaction mixture was stirred for 24 hours at room temperature. Subsequently, sodium bicarbonate (20 mmol) was slowly added, followed by dichloromethane (60 mL). Bromine (1 mL) was added dropwise to the well-stirred two-phase mixture at 6 °C for 20 min. After the addition of bromine, stirring of the reaction mixture was continued for 3 hours. Upon completion of the reaction, the organic layer was separated and the aqueous layer was extracted with dichloromethane (50 mL). The organic extracts were combined, dried with magnesium sulfate, filtered and concentrated under reduced pressure. The residue was recrystallized with hexane (50 mL) to give 1.60 g (81% yield) of a white crystal product with a melting point of 65-66 °C (literature value 19: 63-65 °C).