1-Methyl-2-mercapto-5-imidazole carboxylic acid 1H-Imidazole-4-carboxylic acid, 2,3-dihydro-3-methyl-2-thioxo- 2,3-Dihydro-3-methyl-2-thioxo-1H-imidazole-4-carboxylic acid 2-Mercapto-1-methylimidazole-5-carboxylic acid 4-25-00-01557 (Beilstein Handbook Reference) 64038-57-9 BRN 0130889 EINECS 264-617-9 Imidazole-5-carboxylic acid, 1-methyl-2-mercapto- USAF EL-97