Treatment of uric acid (1) with boiling isobutyric anhydride causes cleavage and rearrangement of the pyrimi-dine and imidazole rings to give a new heterocyclic derivative, 2- (l-methylethyl)-4-(1-hydroxy-2-methylpropylidene) aminoimidazole-5-carboxylic acid 5, l'- lactone (2). The structures of the lactone and related derivatives have been elucidated by infrared spectroscopy, IH and 13C NMR, and mass spectrometry. Experiments with uric ...
![2,5-di(propan-2-yl)-1H-imidazo[4,5-d][1,3]oxazin-7-one Structure](https://image.chemsrc.com/caspic/083/62948-76-9.png)