Synthesis and biological screening of some novel pyrazolo[3′, 4′:4,5]thieno[2,3-d]pyrimidin-8-ones via a Gewald reaction

Abstract

A new synthetic route is proposed for the synthesis of 3,6-dimethyl-6-aryl- 1,5,6,7-tetrahydro-8H-pyrazolo[3′,4′:4,5]thieno[2,3-d] pyrimidin-8-ones 3a-h from 5-amino-3-methyl-1H-thieno[3,2-c]pyrazole-6- carbonitrile 2. Synthesis of the key compound 2 was accomplished via a Gewald reaction. The newly synthesized compounds 3a-h were characterized by elemental analysis, IR, 1H-NMR, 13C-NMR and mass spectroscopic investigation. All the compounds 3a-h were screened for their antitubercular activity against Mycobacterium tuberculosis H37 RV. ©ARKAT USA, Inc.