H_3PW_(12)O_(40)在离子液体中催化β-萘甲醚乙酰化反应

Acylation of 2-methoxynaphthalene with acetic anhydride catalyzed by the H_3PW_(12)O_(40) in ionic liquids

利用吡啶和正溴丁烷合成离子液体中间体[BPy]Br,再由[BPy]Br和NaBF4合成了离子液体[BPy]BF4,对其进行了FT-IR,1 H NMR和TG-DTA表征.将合成的离子液体作为溶剂,磷钨酸为催化剂,催化β-萘甲醚(MM)和乙酸酐(AA)的乙酰化反应.结果表明,该反应的主要产物是2-甲氧基-1-萘乙酮.反应的较佳工艺条件为:β-萘甲醚0.01mol,β-萘甲醚与乙酸酐的摩尔比为1∶1.5,磷钨酸0.05g,100℃下反应4h,反应物β-萘甲醚的转化率达到57.04%,最高选择性可达99.04%.通过萃取分离实现回收磷钨酸-离子液体的催化体系,并可循环使用5次,催化活性无下降.

[BPy]Br was synthesized by pyridine and C4H9 Br firstly and then[BPy]BF4ionic liquid was synthesized by [BPy]Br and NaBF4.The [BPy]BF4was characterized by FT-IR,1 HNMR and TGDTA.Acylation of 2-Methoxynaphthalene with Acetic anhydride was studied using H3PW12O40 as catalyst in [BPy]BF4ionic liquids and main products was 2-methoxyl-1-acetonaphthone.The optimal conditions were as follows：0.01 mol 2-Methoxynaphthalene,n（2-Methoxynaphthalene）：n（Acetic Anhydride）=1∶1.5,0.05 g H3PW12O40and the reaction temperature was 120 ℃,the reaction time was 4h,and the conversion rate was up to 57.04 %,the selectivity of 2-methoxyl-1-acetonaphthone was 99.04 %.The system of H3PW12O40 and ionic liquids could be recycled by extraction and the catalytic activity was not noticeably decreasing after 5times.