The efficient and mild synthesis of phenacyl bromide via bromination using N-bromosuccinimide catalyzed by brønsted acidic ionic liquid under ultrasound irradiation

Tóm tắt

Phenacyl bromide is an important substrate for the synthesis of various biologically active heterocyclic compounds and industrial chemicals. Synthesis of phenacyl bromide via the bromination of the alpha carbon in acetophenone by using N-bromosuccinimide has been carried out in the presence of 1-(4-sulfobutyl)-3-methylimidazolium hydrogen sulfate (BAIL). Under the ultrasound irradiation, the yield of phenacyl bromide and 2,2-dibromo-2-phenylethanone has been achieved at 84% and 11%, respectively, in a very short time, ten minutes.  Additionally, 1-(4-sulfobutyl)-3-methylimidazolium hydrogen sulfate was recovered and reused five times, without significantly reducing the yield of phenacyl bromide. This work has developed an approach that not only improves reaction time and product selectivity but also aligns with 'green chemistry' principles by employing a recoverable and reusable catalyst.