2-imino-3-methyl-5-phenyl-thiazolidin-4-one

N-甲基脲

6-氨基-1,3-二甲基-2,4-二氧代-1,2,3,4-四氢嘧啶-5-甲醛

3-methyl-5-(N-methylcarbamoyl)-2-thiocytosine

5-(N-cyclohexylcarbamoyl)-3-methyl-2-thiocytosine