2C-B-morpholine
2C-B-morpholine, also known as 2C-B-norphenmetrazine or as 2-morpholine, is a serotonin receptor modulator of the phenylmorpholine and cyclized phenethylamine groups. It is a ligand of the serotonin 5-HT2A receptor, with an affinity of 20.6nM and an of 4%. The drug showed 103-fold lower affinity for this receptor than R-DOB and had minimal agonist activity, so for practical purposes would act as an antagonist at the 5-HT2A receptor under most circumstances, despite being technically classified as a partial agonist. 2C-B-morpholine was first described in the scientific literature by Richard Glennon and colleagues by 2004.