29 y/o M was complaining of a headache and collapsed quickly. EMS was known as and resuscitation was unsuccessful. dimethylamino group tremendously enhances the MOR affinity, as in U-47700. In contrast, embedding that same simple nitrogen into a cyclic pyrrolidine ring significantly boosts the KOR affinity, as in U-50488. MOR/KOR https://prosyntheticchems.com/product/u-48800/