Short and straightforward synthesis of 1,7-dimethyl-1,4,7,10-tetraazacyclododecane

A novel, cost-effective, and efficient process for the synthesis of 1,7-dimethyl-1,4,7,10-tetraazacyclododecane 1 has been developed. The two-step process involved the selective conversion of commercially available cyclen to N1,N7-diethylcarbamate cyclen 3 that afforded the title compound in high yield after the reduction step.