6-chloro-1,3-dimethyl-5-nitropyrimidine-2,4-dione

1,3-dimethylpyrido[2,3-d]pyrimidine-2,4-dione

1,3,4-三甲基尿嘧啶

5,5-dichloro-1,3-dimethyl-1,3-diazinane-2,4,6-trione

1,3-dimethylbenzo[g]pteridine-2,4-dione