1-(2-Mercaptoethyl)-4-Phenyl-2-imidazolidinone 
Forty-eight hours after oral administration of l4c_ and 3°S-labeled 
1-(2-mercaptoethyl)-4-phenyl-2-imidazolidinone (II) to a rat, 66% of the 
14¢ and 76% of the 35S radioactivity was excreted in the urine. Three 
compounds were identified: 1-[2-(methylsulfinyl) ethyl ]-4-phenyl-2- 
imidazolidinone (III) (88%); 1-[2-(methylsulfonyl) ethyl ]-4-phenyl-2- 
imidazolidinone (IV) (5%); and 1l-sulfoethyl-4-phenyl-2-imidazolidinone 
CV) CAA): -Ch75I)». 
Compound II was synthesized as a result of studies which indicated 
that it was a metabolite of 2,3,5,6-tetrahydro-6-phenylimidazo[2,1-b] 
thiazole, also known as tetramisole(I) (1751). 
© 
Tetramisole (IL) 
i 
N-CH)-CHySH N-CH)~CHy-S-CH 
ae em 

N-CH2-CH,-S03 Na* 

239 
