3-[2-(4-Amino-phenyl)-2-oxo-ethyl]-5-phenyl-5-propyl-imidazolidine-2,4-dione 、
N-tert-butoxycarbonyl-proline 以to yield pyrrolidine-2-carboxylic acid {4-[2-(2,5-dioxo-4-phenyl-4-propyl-imidazolidin-1-yl)-acetyl]-phenyl}-amide的产率得到pyrrolidine-2-carboxylic acid {4-[2-(2,5-dioxo-4-phenyl-4-propyl-imidazolidin-1-yl)-acetyl]-phenyl}-amide