5-Nitrobarbituric acid480-68-2100 % similar 5-Amino-2,4,6(1H,3H,5H)-pyrimidinetrione118-78-543 % similar 5-Methylhydantoin616-03-535 % similar 1,3-Diethyl 2-nitropropanedioate603-67-834 % similar 5-Isopropylhydantoin16935-34-533 % similar Murexide3051-09-032 % similar 5-Ethylhydantoin15414-82-132 % similar Dihydrothymine696-04-832 % similar 2-Nitropropane79-46-932 % similar Allantoin97-59-631 % similar Parabanic acid120-89-831 % similar Phenylhydantoin89-24-731 % similar