The 2,4-dioxopentanoic acid derivatives (3d-f) were obtained from the reaction of 4- acetyl-5-(1-naphthyl)furan-2,3-dione (1) with various nitrogenous nucleophiles (2d-f). The structures of these newly synthesized compounds (3d-f) were determined from the FT-IR, 1H and 13C NMR spectroscopic data and elemental analyses. Theoretical Study of derivatives of (3Z)-3-{2-naphthyl[2- (4-nitrophenyl)hydrazino]methylene}-2,4-dioxopentanoic acid (3d-f) were carried out by using DFT/B3LYP method with basis set of the 6-311G(d,p) in order to find molecular properties by Gaussian 03 program [1](see Schemes 1and 2). According to EHOMO and softness values; electronic give trends for investigated molecules can be written as: 3f>3d>3e.The EHOMO and EHOMO energy gap of a measure of stability. Additionally, according to EHOMO and EHOMO energy gap; stability give trends for investigated molecules can be written as: 3e>3d>3f.