茶碱

8-trifluoroacetoxymercuritheophylline

8-bromo-1,3-dimethyl-7-(1,1-dioxothietan-3-yl)-3,7-dihydro-1H-pyrine-2,6-dione

1,3-二甲基尿酸

1,3-二甲基-8-硝基-1H-嘌呤2,6(3H,9H)-二酮