A convenient, novel approach for the synthesis of polyaza macrocyclic bifunctional chelating agents

Article abstract of DOI:10.1016/0040-4039(96)01727-3

The convenient synthetically useful bifunctional chelating agents, (10-p-aminobenzyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triacetate (p-ABz-DO3A) 3 and (11-p-aminobenzyl)-1,4,8,11-tetraazacyclotetradecane-1,4,8-triacetate (p-ABz-TE3A) 6, were obtained by reaction of an ethyl bromoacetate with 1,4,7,10-tetraazacyclododecane and 1,4,8,11-tetraazacyclotetradecane followed by reaction with nitrobenzyl bromide. This method proved more efficient than any described in the literature since the overall yield in a two-step synthesis sequence starting from tetraazamacrocycles was 68%.