6-甲氧基-1,3-二甲基脲嘧啶

1-methyl-2,4-dimethoxy-6-oxo-1,6-dihydropyrimidine

2,4,6-三氯-5-甲基嘧啶

9-(benzylideneamino)-1-methyl-3H-purine-2,6-dione

3-methylchromeno[2,3-d]pyrimidine-2,4-dione