室温离子液体[BMPy]Br_3和[Bmin]Br_3对芳基烷基酮的选择性溴化反应

Selective α-monobromination of alkylaryl ketones with [BMPy]Br_3 or [Bmin]Br_3

目的研究2种室温离子液体三溴化1丁-基-3甲-基吡啶([BMPy]Br3)和三溴化1丁-基-3甲-基咪唑([Bmin]Br3)分别与6-甲氧基-2乙-酰基萘、4甲-基苯乙酮、4乙-基苯乙酮、2,4二-氯苯戊酮、2羟-基苯丙酮、3-硝基苯乙酮、2,4二-氯-5氟-苯乙酮、3-溴-4羟-基苯丙酮、2氯--4-(4氯-苯氧基)苯乙酮、4-苄氧基苯戊酮的α-溴化反应。方法在无溶剂、室温条件下离子液体与芳基烷基酮反应,柱层析分离产品,离子液体回收重复使用。结果顺利制备得到10个α-溴代芳基烷基酮。结论 [BMPy]Br3和[Bmin]Br3作为溴化剂选择性好,反应条件温和,收率高,操作简便,环境友好。

Objective To investigate the selective α-monobromination of 1-（6-methoxynaphthalen-2-yl） ethanone, 1-（ p-tolyI ） ethanone, 1-（ 4-ethylphenyl ） ethanone, 1-（ 2,4-dichlorophenyl ） pentan-l-one, 1-（ 2- hydroxylphenyl） propan-1 -one, 1 - （ 3-nitrophenyl ） ethanone, 1 - （ 2,4-diehloro-5-fluorophenyl ） ethanone, 1 - （ 3- bromo-4-hydroxyphenyl） propan-1 -one, 1 - [ （ 2-chloro-4- （4-chlorophenoxy） phenyl ethanone, 1 - [ （ 4- （ benzylo- xy） phenyl] pentan-l-one with [ BMPy] Br3 and [ Bmim] Br3. Methods The ionic liquids reacted with alkylaryl ketones in room temperature under solvent-free conditions, the products was separated by column chromatography, and the ionic liquid was recycled and reused. Results Ten α-bromo-alkylaryl ketones were obtained in good yields and highly selective. Conclusion [ BMPy ] Br3 and [ Bmim ] Br3 as bromine sources proves to be a highly efficient, simple, regioseleetive reagent for electrophilic bromination of various alkylaryl ketones.