1114546-30-3

757247-93-1

1114546-30-3

Using 4-amino-2-fluoro-3-methylbenzonitrile (10 g, 66.6 mmol) as starting material, potassium nitrite (22.67 g, 266 mmol) and copper (I) bromide (1.911 g, 13.32 mmol) were dissolved in dimethyl sulfoxide (400 mL). Subsequently, 48% aqueous hydrogen bromide solution (33 mL, 266 mmol) diluted with dimethyl sulfoxide (200 mL) was added dropwise and the reaction mixture was stirred for 2 hours. Upon completion of the reaction, complete conversion of the feedstock was confirmed by thin layer chromatography (TLC) monitoring. The reaction mixture was slowly poured into ice-cold water and neutralized with cold concentrated sodium hydroxide solution to pH 7. The precipitated solid was collected by filtration to afford the target product 4-bromo-2-fluoro-3-methylbenzonitrile (11.4 g, 53.3 mmol, 80% yield) as a white solid. The product was characterized by 1H NMR (400 MHz, CDCl3): δ 7.47 (d, J = 9.37 Hz, 1H), 7.33 (t, 1H), 2.39 (d, J = 2.34 Hz, 3H).