p-Nitrobenzyl-diazoacetoacetate

p-Nitrobenzyl 2-diazoacetoacetate

4-Nitrobenzyl 2-diazoacetoacetate

4-nitrobenzyl 2-diazo-3-oxobutanoate

2-diazo-5-(4-nitrophenyl)-3-oxopentanoate

Butanoic acid,2-diazo-3-oxo-, (4-nitrophenyl)Methyl ester