Synthesis and characterization of novel indazole-4,7-dione derivatives

ORGN 629

Solomon Berhe, solarefaine@hotmail.com and Oladapo Bakare, obakare@howard.edu. Department of Chemistry, Howard University, 525 College Street, Washington DC, DC 20059
Heterocyclic quinones have various important biological activities, including their antitumor activities. Some benzimidazole-4,7-diones, indole-4,7-diones, and benzothiazole-4,7-diones have been reported to exhibit cytotoxic activities against different types of cancer cell lines. By replacing the imidazole, pyrrole, and thiazole ring in the above heterocyclic quinones with the pyrazole ring, we synthesized some novel substituted indazole-4,7-diones as potential anticancer agents. Nitrosation of tetrahydro-2-pyrimidone furnished N-nitrosotetrahydro-2-pyrimidone which reacted with potassium methoxide in methanol to generate 3-(N-carbomethoxyamino)-1-diazopropane. The in-situ cycloaddition of the diazopropane intermediate with various phenylaminobenzoquinone and naphthoquinone derivatives in a mixture of THF/Et2O at room temperature furnished the corresponding indazole-4,7-dione derivatives. The synthesis, infrared (IR), 1H-NMR and 13C-NMR spectroscopic analyses of these compounds are reported.