Synthesis of Acyl Derivatives of Prolyl-leucinamides

Synthetic routes to prolyl-leucinamide, N-benzyl(prolyl)leucinamide, and N-(prolyl-leucyl)morpholine were proposed. Treatment of these compounds with benzoyl chloride or acetyl chloride in the presence of triethylamine afforded the corresponding (N-acylprolyl)leucinamides. Acyl derivatives of N-benzyl(prolyl)-leucinamide, and N-(prolyl-leucyl)morpholine were also synthesized by condensation of (N-benzoylprolyl)-leucine or (N-acetylprolyl)leucine with benzylamine or morpholine in the presence of N, N′-dicyclohexyl-carbodiimide.