3-Benzhydrylmorpholine

3-Benzhydrylmorpholine is a drug that was developed by American Home Products in the 1950s. It has stimulant and anorectic effects and is related to both pipradrol and phenmetrazine.

Synthesis
The Ethyl ester of β-Phenylphenylalanine (Diphenylalanine), i.e. ethyl 2-amino-3,3-diphenylpropanoate (CID:101017845) (1) is the starting material. Lithium aluminium hydride reduction of the ester to the primary alcohol gives 2-amino-3,3-diphenylpropan-1-ol, CID:15798949 (2). Acylation of the primary amine with chloroacetyl chloride [79-04-9] (3) gives 2-chloro-N-(3-hydroxy-1,1-diphenylpropan-2-yl)acetamide (4). Base catalyzed ring closure affords the lactam, i.e. 5-benzhydrylmorpholin-3-one (5). Further treatment with lithium aluminium hydride reduces the lactam function to the morpholine ring, thus 3-benzhydrylmorpholine is formed (6).