Synthesis and resolution of the novel appetite suppressant 2-benzylmorpholine, a nonstimulant isomer of phenmetrazine

The synthesis of 2-benzylmorpholine from allylbenzene together with its resolution into its (+)- and (-)-enantiomers is reported. Oral dosing of the racemate to dogs caused appetite suppression with an ED50 of 3 and 5.5 mg kg-1 at 1 and 2 h, respectively, after access to a meat meal. No stimulant activity was observed in dogs given oral doses of 200 mg kg-1 but the appetite suppressant effect in dogs declined during 20 days of chronic oral dosing at 10 mg kg-1. Appetite suppression activity was shown to reside in the (+)-enantiomer.