The synthesis of several nitrogen-substituted alkyl, substituted alkyl and aryl derivatives of spiropiperidine-4', 5-barbituric acid is reported. It has been observed that the stability of the spiro-l'-methylpiperidine-4', 5-barbituric acid is of the same order of magnitude as barbital and is somewhat more stable than the spirotetrahydropyran-or the spirocyclopentanebarbituric acids. The pharmacological examinations of the 1'-phenyl- ...
![3-oxa-8,10-diazaspiro[5.5]undecane-7,9,11-trione Structure](https://image.chemsrc.com/caspic/493/5721-46-0.png)
