2-氨基-4-氧代-4H-3,1-苯并恶嗪-8-羧酸

2,4-dioxo-1H-3,1-benzoxazine-8-carboxylic acid

4-羧基-9-茚酮

3,4-二氢-4-氧-8-喹唑啉羧酸

2-(4-methoxyanilino)benzene-1,3-dicarboxylic acid