Bromomalononitrile was prepared by bromination of malononitrile by the method of Ferris, et al.5 To this end, bromine (48.5 g, 0.30 mol) was added over a period of 5 hr to malononitrile (20 g, 0.30 mol) dissolved in water (300 mL) in an ice bath, and kept overnight under those conditions. A slight brown-white precipitate separated from the solution. It was washed with water and taken up in CHCl3 (100 mL). After drying (Na2SO4) and concentrating under reduced pressure to about one half the original volume, the solution was cooled in a refrigerator to deposit colorless crystals, which were then purified by recrystallization from CHCl3 to give 21 g (48%) of the desired bromomalononitrile , mp 63-64°C (Ferris, et al.,5 reported 20% yield). Org. Synth. 1998, 75, 210 DOI: 10.15227/orgsyn.075.0210
