Ketonic oxidation products of cyclobarbital.

Chemical or biochemical oxidation of cyclobarbital yielded 5-(3-oxo-1-cyclohexen-1-yl)-5-ethyl -2,4,6,- (1H,3H,5H)-pyrimidinetrione, and photochemical oxidation gave 5-(6-oxo-1-cyclohexen-1-yl)-5-ethyl-2,4,6-(1H,3H,3H)-pyrimidinetrione. These compounds were isolated and purified by TLC, and their structures were determined by UV, IR, NMR, and mass spectral data; the crystalline structure was determined by X-ray diffraction.