Synthesis and biological screening of some novel pyrazolo[3’,4’:4,5]thieno[2,3-d]pyrimidin-8-ones via 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, 1 H-NMR, 13 C-NMR and mass spectroscopic investigation. All the compounds 3a-h were screened for their antitubercular activity against Mycobacterium tuberculosis H 37 RV.

A catalyst- and solvent-free protocol for the sustainable synthesis of fused 4H-pyran derivatives

“… 6 Among the fused heterocycles, pyrazole- and coumarin-fused oxygen-containing heterocyclic systems, particularly 4 H -pyran derivatives, are omnipresent in several natural and unnatural bioactive molecules with promising properties both in pharmacological and materials sciences. 7 Pyrazole-fused 4 H -pyran derivatives have shown several biological activities such as antimalarial, 8 antibacterial, 9 antimicrobial, 10 anti-inflammatory, 11 anti-tubercular, 12 hypoglycemic and vasodilator activities. 13 On the other hand, coumarin-fused 4 H -pyrans also exhibit several activities like antioxidant, 14 antifungal 15 and anticancer.…”