triethyl prop-1-ene-1,1,2-tricarboxylate

2-amino-4,6-dioxo-4a,5-dihydropteridine-7-carboxylic acid

2-amino-4,7-dioxo-1,8-dihydropteridine-6-carboxylic acid

草酸二乙酯

亚乙基四羧酸四乙酯