2-乙氧基-2-氧代乙酸酐

methyl 2-(dimethylamino)-2-oxoacetate

2-methoxy-2-oxoacetate

甲基2-(3,4-二甲氧基苯基)-2-氧代乙酸酯

methyl 2-(4-chloroanilino)-2-oxoacetate