No abstract

No abstract

No abstract

N-Aryl-C-ethoxycarbonylnitrile imines (3a-g) react with ethyl cyanoacetate 1 in 1,3-dipolar cycloaddition to yield novel pyrazole-3,4-dicarboxylates (4a-g) in moderate yields. The reaction of pyrazole-3,4-dicarboxylates (4a, d) with hydrazine afforded pyrazolo[4,3-d]pyridazine-4,7-diones (5a, d) in good yields. All compounds were fully characterized by spectroscopic methods. Some of the newly synthesized compounds were evaluated for their cytotoxic activity against murine P815 mastocytoma cell line.

The molecule of the title compound, C16H12N6O4, is built up from two fused five- and six-membered rings linked by an ethylene group. The dihedral angle between the planes through the indazole ring systems is 39.74 (5)°. The nitro groups are tilted by 7.2 (2) and 8.5 (2)° with respect to planes of the fused-ring systems. In the crystal, molecules are linked by C—H...N and C—H...O hydrogen bonds into chains running parallel to thecaxis.