Synthesis of C- and N-functionalised derivatives of 1,4,7-triazacyclononane-1,4,7-triyltriacetic acid (NOTA), 1,4,7,10-tetra-azacyclododecane-1,4,7,10-tetrayltetra-acetic acid (DOTA), and diethylenenetriaminepenta-acetic acid (DTPA): bifunctional complexing agents for the derivatisation of antibodies

Using (2S)-lysine as a precursor, the syntheses of aminobutyl derivatives of 1,4,7-triazacyclononane, 1,4,7,10-tetra-azacyclododecane, and 3-azapentane-1,5-diamine are described. Transformation into their reactive maleimide derivatives is described and alternative strategies for synthesising the title complexing agents involving nitrogen functionalisation are defined.