Ethotoin ±>3-Ethyl-5-phenylhydantoin

V-Subslilulion and 5,5-disubstitution prevent ring opening as demonstrated by various examples. Ethotoin (3-ethyl-5-phenylhydantoin, 4.230), in contrast to its /V-dcclhylalcd metabolite, was not detectably hydrolyzed by DHPase. No ring-opened metabolite was found for phenytoin (5,5-diphenyl-hydantoin, 4.231) or nirvanol (5-ethyl-5-phenylhydantoin, 4.232), which is the AT-demethylated metabolite of mephenytoin (4.233) [144],... 

Ethotoin (3-ethyl-5-phenylhydantoin) is a chiral anticonvulsant drug with utility in generalized tonic-clonic and complex partial seizures. In six healthy volunteers given single 1 g oral doses, the only significant difference between enantiomers was in the AUC, which was 580 and 510 pg x h/mL for the R(—) and S(-l-) enantiomers, respectively [166]. 

A Gas Chromatographic Method for the Determination of Ethotoin (3-Ethyl-5-phenylhydantoin) in Human Plasma... 

Benzaldehyde cyanohydrin is reacted with urea to displace the hydroxyl group of the cyanohydrin. That intermediate is treated with HCI to convert the urea nitrogen to a nitrile. The resultant imine is hydrolyzed to the phenylhydantoin. Alkylation with ethyl iodide gives ethotoin, as described by A. Pinner in Chem. Ber. 21, 2325 (1888). 

Ethotoin Ethotoin, 3-ethyl-5-phenylimidazolidine-2,4-dione (9.1.5), is synthesized in basically the same manner as described above, which in this case involves the reaction of benzaldehyde oxynitrile (9.1.2), with urea or ammonium hydrocarbonate, which forms the intermediate urea derivative (9.1.3) which on acidic conditions (9.1.3) cycUzes to 5-phenylhydantoin (9.1.4). Alkylation of this product using ethyliodide leads to the formation of ethotoin (9.1.5) [3,4]. 

Ethyl-5-phenylhydantoin (Ethotoin) [86-35-1] M 204.2, m 94 . Crystd from water. 

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