4-Bromocrotonic acid

107-93-7

13991-36-1

General procedure for the synthesis of (E)-4-bromobut-2-enoic acid from crotonic acid: a mixture of (E)-but-2-enoic acid (10.00 g, 116.16 mmol), N-bromosuccinimide (NBS, 1.02 g, 118.48 mmol), and 2,2'-azobis(2-methylpropionitrile) (AIBN, 381.49 mg, 2.32 mmol ) were dissolved in carbon tetrachloride (CCl4, 120 mL) and the reaction was stirred at 90 °C for 4 hours. After completion of the reaction, the mixture was filtered and the filtrate was concentrated. The residue was recrystallized with hexane to afford the target product (E)-4-bromobut-2-enoic acid (19.17 g, 42.2% yield).