Modification of Thionucleobases in Ionic Liquids

A simple method was established for the preparation of thio-substituted thionucleobases using room temperature ionic liquids (RTILs) such as 1-butyl-3-methylimidazolium trifluoroacetate [BMIM](+)[CF3COO](-) and 1-methoxyethyl-3-methylimidazolium trifluoroacetate [MeOEtMIM](+)[CF3COO](-) as solvents and catalysts without any other catalyst. These reactions proceeded efficiently in RTILs with excellent yield of products. RTILs can be recycled and reused effectively without further purification.