ethyl 2-(6,8-dibromoimidazo[1,2-a]pyrazin-2-yl)acetate

ethyl 4-chloro-3,3-diethoxybutanoate

4-(4-甲基苯氧基)-3-氧代丁酸乙酯

ethyl 2-(4H-1,4-benzothiazin-3-ylidene)acetate

ethyl 4-(N-methylanilino)-3-oxobutanoate