4,6-dimethyl-[1,2,5]oxadiazolo[3,4-d]pyrimidine-5,7-dione

6-(乙基硫代)-1,3-二甲基尿嘧啶

3,3,5,7-tetramethylpyrimido[5,4-c][1,2,5]oxadiazine-6,8-dione

尼非卡兰

6-(chloromethyl)-1,3-dimethylpyrimidine-2,4-dione