Preparation of 99Tcm-labeled dopamine D2 receptor imaging agent m-Br-p-EBZM

The purpose of the presented work is to synthesize 99Tcm-labeled dopamin D2 receptor imaging agent 2-{1-[(1-Ethoxycarbonyl-2-mercapto-ethylamino)-methyl]}-3-{4-[(1-ethyl pyrrolidin-2-ylmethyl)-carbamoyl] -3-methoxy-5-bromo-phenylamino}-propylamino)-3-mercapto-propionic acid ethyl ester (99Tcm-m-Br-p-EBZM). The ECD was coupled with the benzamide derivative, N-[(1-ethyl-2-pyrrolidinealkyl)methyl]-4-acetylamino-5-bromium-2- methyloxygen-= benzol formamide, to yield m-Br-p-EBZM. The labeling compound was prepared through two steps of exchange labeling with 99Tcm-glucohetonate, and its stability was observed. Results show that m-Br-p-EBZM was synthesized for the first time, and was successfully labeled with 99Tcm with 98% of radiochemical purity, high stability and good liposolubility,. Hence 99Tcm-m-Br-p-EBZM may become a potential dopamine D2 receptor imaging agent. (authors)