THE METABOLIC CONVERSION OF 3-METHYL-5-ETHYL-5-PHENYL HYDANTOIN (MESANTOIN) AND OF 5-ETHYL-5-PHENYL HYDANTOIN (NIRVANOL) TO 5 - ETHYL -5- (p-HYDROXYPHENYL) HYDANTOIN

¹ Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina

5-Ethyl-5-(p-hydroxyphenyl) hydantoin ("p-hydroxynirvanol") has been found in the urine of dogs after the administration of 3-methyl-5-ethyl-5-phenyl hydantoin (Mesantoin) or 5-ethyl-5-phenyl hydantoin (Nirvanol). The same product has been isolated from the urine of a man receiving Mesantoin.

The p-hydroxynirvanol from dog urine consists largely of the dextrorotatory isomer. That from human urine is optically inactive.

The p-hydroxynirvanol in dog urine is largely conjugated with glucuronic acid. p-Hydroxynirvanol lacks the characteristic anesthetic activity of Nirvanol. The synthesis and the resolution of p-hydroxynirvanol are described.