Background:

DOTA derivative is a benxyl derivative of the cyclic tosamide; can be nitrated directly; is more convenient to incorporate the nitro group after deprotection lithium aluminum hydride.

[1]. Martha L Gilbert, et al. A new synthetic route to 2-(p-nitrobenzyl)-1,4,7,10-tetraazacyclododecane. doi:10.1016/S0040-4039(00)73873-1