5-(6-ethoxycarbonylhexyl)-1-(5-phenylpentyl)hydantoin 、
sodium hydroxide 在
silica gel 作用下,
以to give 5-(6-carboxyhexyl)-1-(5-phenylpentyl)hydantoin crystallising from ethyl acetate-light petroleum (b.p. 60°-80° C.) in colourless prismatic needles, m.p. 90°-92° C.的产率得到5-(6-carboxyhexyl)-1-(5-phenylpentyl)-hydantoin