2-(2-Amino-3,5-dinitrophenyl)-2-oxoacetic acid (2) was obtained from hydrolysis of 5,7-dinitroisatin (1) in alkaline media. A novel quinoxaline derivative (3) was synthesized from the reaction of the same compound (1) with o-phenylenediamine. Reacting 2 with ethyl 3-oxo-3-phenylpropanoate yields 6,8-dinitro-2-phenylquinoline-3,4-dicarboxylic acid (4). Then, 4 was converted into new quinoline-diacylchloride, quinoline-ester, quinoline-dicarboxamide, pyridazine, and pyrroledione derivatives (5, 6a, 6b, 6c, 6d, 7a, 7b, 7c, 7d, 8, 9, 10a, 10b, 10c, 10d, 11a, 11b, 12) with SOCl2, alcohols, amines, and hydrazines, respectively. The structures of synthesized compounds were clarified by H-1 NMR, C-13 NMR, IR, mass and elemental analysis methods.