3-Methoxy-3-oxopropanenitrileMethyl cyanoacetatemethyl 2-cyanoacetate氰乙酸甲酯Methyl cyanoacetateCyanoacetic acid methyl ester氰基乙酸甲酯Malonic methyl ester nitrilemethyl cyanoacetate2-cyanoacetic acid, methyl esterMethyl cyanoethanoateCyanoacetic acid methyl ester