2-Phenylmorpholine (code name PAL-632) is the parent compound of the substituted phenylmorpholine class of compounds. Examples of 2-phenylmorpholine derivatives (i.e., substituted phenylmorpholines) include phenmetrazine (3-methyl-2-phenylmorpholine), phendimetrazine ((2S,3S)-3,4-dimethyl-2-phenylmorpholine), and pseudophenmetrazine ((2RS,3SR)-3-methyl-2-phenylmorpholine), which are monoamine releasing agents (MRAs) and psychostimulants. 2-Phenylmorpholine itself is a potent norepinephrineâÂÂdopamine releasing agent (NDRA) and hence may act as a stimulant similarly.