(+/-)-3-[2-(4-amino-phenyl)-2-oxo-ethyl]-5-ethyl-5-phenyl-imidazolidine-2,4-dione 、
四氢呋喃-3-羰酰氯 以to yield tetrahydro-furan-3-carboxylic acid {4-[2-(4-ethyl-2,5-dioxo-4-phenyl-imidazolidin-1-yl)-acetyl]-phenyl}-amide的产率得到tetrahydro-furan-3-carboxylic acid {4-[2-(4-ethyl-2,5-dioxo-4-phenyl-imidazolidin-1-yl)-acetyl]-phenyl}-amide