The present invention comprises novel analogs of ecstasy-class compounds and novel ecstasy-class immunogens leashed out of, i.e., derived from, the methylenedioxy position. The invention also comprises unique monoclonal antibodies generated using MDO-leashed MDMA immunogens as well as unique conjugates and tracers. These antibodies, conjugates, and tracers are useful in immunoassays for the detection of ecstasy-class compounds in biological fluids.