2，4-二甲氧基-5-硝基苯甲酸

4,6-dimethoxy-3-oxo-1H-2-benzofuran-1-carboxylic acid

5-溴-2,4-二甲氧基苯甲酰氯

1,6-dihydroxyxanthen-9-one

5-acetyl-2,4-dimethoxybenzoic acid