3-ethoxy-1H-pyrazole-4-carboxylic acid ethyl ester

Ethyl 8-methyl-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxylate

Ethyl 6-fluoro-4-oxo-1,4-dihydro-3-quinolinecarboxylate

diethyl 4-oxoquinolizine-1,3-dicarboxylate

diethyl 2-[(benzylamino)methylidene]propanedioate