Cyclic ureas, III: On the metabolism of the enantiomers of cyclic ureas in rats.

Studies are described on the metabolism of the enantiomers of 1, 2, and 3 in rats. The metabolites were identified in urine after cleavage of conjugates and extraction using gas chromatography-mass spectrometry. Qualitative enantioselective differences of the metabolism of 1, 2, and 3 could not be detected. Because oxidation of 1 and 2 to the corresponding barbiturates could not be found and 3 was oxidized to mephenytoin only in minor amounts, this pathway is not a prerequisite for the sedative-hypnotic effects of 1, 2, and 3.