1-(2-羟基乙基)-3,7-二甲基黄嘌呤

1-methyl-1,3-diazinane-2,4,5,6-tetrone

N-甲基脲

1-methyl-5-hydroxyhydantoin-5-carboxamide

1-甲基咪唑烷-2,4,5-三酮