Synthesis of distillable mesoionic liquids

以异硫氰酸烷基酯和叠氮化钠为原料制备了一系列1,3-二烷基四唑-5-油酸酯，并与硫酸二烷基酯进行烷基化反应。有些在室温下是低粘度的液体，可以通过蒸馏提纯。1-丁基-3-甲基四唑-5-酸酯被转化为相应的硫代酸酯和酰胺，其中一些还被发现以液体形式存在。介离子液体可作为极性溶剂用于Mizoroki-Heck反应和Miyaura-Suzuki偶联反应，并且易于回收和循环利用。

A series of 1,3-dialkyltetrazolium-5-olates was prepared from alkyl isothiocyanates and sodium azide, followed by alkylation with dialkyl sulfates. Some of them are liquid with low viscosity at room temperature and can be purified by distillation. 1-Butyl-3-methyltetrazolium-5-olate was converted to the corresponding thiolate and amides, some of which were also found to exist as liquid. The mesoionic liquid serves as a polar solvent for the Mizoroki-Heck reaction and the Miyaura-Suzuki coupling and can be easily recovered and recycled.