Carcinogenicity of 5-Nitrofurans, 5-Nitroimidazoles, 4-Nitrobenzenes, and Related Compounds,

Summary 1-[(5-Nitrofurfurylidene)amino]hydantoin gave negative results in chronic carcinogenicity tests in rats. Carcinogenic response was moderate for 4-methyl-1-[(5-nitrofurfurylidene)amino]-2-imidazol-idinone and 1-(2-hydroxyethy l)-3-|(5-nitrofurfurylidene)amino]-2-imidazolidinone, and strong for l-5-morpholinomethyl-3-[(5-nitrofurfurylidene)amino]-2-oxazolidinone hydrochloride and 1 -[(5-nitrofurfurylidene)aminol-2-imidazolidinone. Several other nitrofurans, nitrobenzenes, aminobenzenes, nitroimidazoles, and related compounds were also tested for carcinogenicity with varying results. 5-Nitro-2-furamidoxime, 2-hydrazino-4-phenylthiazole, D-(—)-threo-1 -(p-nitrophenyl)-2-dichloroacetamido-1,3-propanediol, 1-(2-hydroxyethyl)-2-methyl-5-nitroimidazole, and 2-amino-5-phenyl-2-oxazolin-4-one with Mg(OH)2 gave negative results; hexamethylmelamine and 1,2-dimethyl-5-nitroimidazole were weakly tumorigenic; 4,6-diamino-2-(5-nitro-2-furyl)-s-triazine and its bisacetamide, formic acid 2-[4-(5-nitro-2-furyl)-2-thiazolyl]-hydrazide, 2-(2,2-dimethylhydrazino)-4-(5-nitro-2-furyl)thiazole, 2-hydrazino-4-(p-nitrophenyl)thiazole, and 2-hydrazino-4-(p-aminophenyl)thiazole were strongly carcinogenic. The significance of the structural variations is discussed with respect to nitrofuran carcinogenesis and the possible carcinogenicity of other nitroaromatic compounds.