Abstract The crystal and molecular structures of vardenafil (free, unprotonated base), vardenafil dihydrate and the hydrochloride salts, vardenafil monohydrochloride trihydrate and vardenafil dihydrochloride hexahydrate, were determined by single-crystal X-ray diffraction. The crystal structure of vardenafil monohydrochloride trihydrate is in good agreement with the published crystal structure obtained by powder diffraction using synchrotron radiation. This work shows that the crystal structure of anhydrous vardenafil free base is very similar to the crystal structure of sildenafil free base.

中文翻译：

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伐地那非、伐地那非二水合物、伐地那非单盐酸盐三水合物和伐地那非二盐酸盐六水合物的单晶 X 射线结构测定

摘要 伐地那非（游离、非质子化碱）、伐地那非二水合物及其盐酸盐、伐地那非一盐酸盐三水合物和伐地那非二盐酸盐六水合物的晶体和分子结构通过单晶X射线衍射测定。伐地那非单盐酸盐三水合物的晶体结构与使用同步辐射通过粉末衍射获得的公开晶体结构非常一致。这项工作表明无水伐地那非游离碱的晶体结构与西地那非游离碱的晶体结构非常相似。