Functional Derivatives of Sterically Hindered Amines: Piperazine diesters

Several diesters of dicarboxylic acids with pendant sterically hindered amines of the piperazine type were prepared from α-bromo- and α,α′-dibromosubstituted dicarboxylic acid esters by reactions with 14,16-dioxo-7,15-diaza-dispiro[5,1,5,3]hexadecane and 7,15-diazadispiro [5,1,5,3] hexadecane.