3,4-Dihalo-2(5H)-furanone initiated ring-opening reaction of DABCO in the absence of metal catalyst and additive and its application in one-pot multicomponent reaction

In the absence of metal catalysis and additive, ethyl acetate as the solvent at 95 oC under air atmosphere for 2 h, an eco-friendly and practical protocol for the synthesis of 4-ethylpiperazine derivatives through the reaction of 3,4-dihalo-2(5H)-furanone initiated ring-opening reaction of DABCO is developed. There is a satisfactory reactivity with moderate to excellent yields as well as 100% atom economy. This potential bioactive synthon promoted ring-opening reaction is not only important for the development of new drugs, but also suitable for other cyclic tertiary amine (e.g. 1-methylpyrrolidine) in good yields. In addition, due to the newly generated alkyl halide structural unit in the product, its application in one-pot multicomponent reaction with different kinds of nucleophilic reagents can be achieved as designed.