Synthesis and pharmacological evaluation of 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline derivatives as sigma-2 receptor ligands.

Increasing evidences have implicated that sigma-2 receptor is a biomarker and significantly over-expressed in many proliferative cancer cells with no or low expression in normal cells. Sigma-2 receptor selective ligands have been successfully used as valuable tools to study its pharmacological functions, tumor imaging, and cancer therapeutics or adjuvants. 6,7-Dimethoxy-1,2,3,4-tetrahydroisoquinolinylalkyl benzamides are among a few categories of structures that have demonstrated high affinities and selectivities for sigma-2 receptor and been used extensively as study tools in various tumor imaging and therapy.