Characterization and biological evaluation of some novel pyrazolo [3',4':4,5]thieno [2,3-d] pyrimidin-8-ones synthesized via the Gewald reaction

摘要

The synthesis of substituted pyrazolo[3',4':4,5]thieno[2,3-d]pyrimi-din-8-ones (IIIa-j) from 5-amino-3-methyl-lH-thieno[3,2-c]pyrazole-6-carbo-nitrile (II) is described. The key compound II was synthesized from (5-methyl--2,4-dihydro-3H-pyrazol-3-ylidene)malononitrile I via the Gewald reaction. The synthesis of the title compounds IIIa-j was accomplished by condensation of II with different aromatic aldehydes. The newly synthesized heterocyles were characterized by elemental analysis, IR, ~1H-NMR, ~(13)C-NMR and mass spectro-scopic investigation. All the newly synthesized compounds were evaluated for antimicrobial activity against a variety of bacterial strains.