N′-Activation of N-Arylimidazoles: Facile Syntheses of N-Alkyl-N′-arylimidazolium Iodides from Less Expensive Chloro Substrates
作者:Michael Chetcuti、Anna Oertel、Vincent Ritleng
DOI:10.1055/s-0028-1088053
日期:2009.5
A series of N,N′-asymmetrically substituted imidazolium iodide salts have been synthesized, starting from N-arylimidazoles and the less expensive, but less reactive, 1-chlorobutane or (3-chloropropyl)trimethoxysilane. The addition of potassium iodide and the use of 1,2-dimethoxyethane as a solvent lead to multigram quantities of these salts becoming readily available, in yields ranging from 50% to 94%. Direct combination of (3-chloropropyl)trimethoxysilane with 1-mesityl-1H-imidazole was also effected, in good yield, by using a microwave oven at 180 ËC. The synthesis of two 1-alkyl-3-isopropylimidazolium chlorides is also presented herein.
一系列N,N′-非对称取代的咪唑碘盐已被合成,合成原料是通过N-芳基咪唑和较为廉价但反应活性较低的1-氯丁烷或(3-氯丙基)三甲氧基硅烷来实现。添加碘化钾并使用1,2-二甲氧基乙烷作为溶剂,使得这些盐类以50%到94%的产率稳定地获得,数量可达克级。此外,还通过在180℃下使用微波炉,高效地实现了(3-氯丙基)三甲氧基硅烷与1-2-甲基-1H-咪唑的直接反应。本文还介绍了两种1-烷基-3-异丙基咪唑氯化物的合成方法。