Substituted phenylmorpholine
Substituted phenylmorpholines, or substituted phenmetrazines alternatively, are chemical derivatives of 2-phenylmorpholine or of the psychostimulant drug phenmetrazine. Most such compounds act as releasers of monoamine neurotransmitters, and have stimulant effects.
Source: Wikipedia — Substituted phenylmorpholine (CC BY-SA 4.0)