2-Thioguidanthion 2-Thiohydantoin 2-Thioxo-4-imidazolidinone 4-Imidazolidinone, 2-thioxo- 5-24-05-00241 (Beilstein Handbook Reference) 503-87-7 AI3-61106 BRN 0110599 EINECS 207-977-4 HYDANTOIN, 2-THIO- NSC 11772 Thiohydantoin USAF BE-25