Heterocyclization of polarized system: synthesis, antioxidant and anti-inflammatory 4-(pyridin-3-yl)-6-(thiophen-2-yl) pyrimidine-2-thiol derivatives

Abstract

Abstract Background Chalcones are intent in the daily diet as a favorable chemotherapeutic compound; on the other hand thiophene moiety is present in a large number of bioactive molecules having diverse biological efficiency. Results Our current goal is the synthesis of (E)-1-(pyridin-3-yl)-3-(thiophen-2-yl) prop-2-en-1-one 3 that’s used as a starting compound to synthesize the novel pyrimidine-2-thiol, pyrazole, pyran derivatives. Chalcones 3 was prepared by condensation of 3-acetylpyridine with thiophene 2-carboxaldehyde which reacted with thiourea to obtain pyrimidinthiol derivative 4. Compound 4 was allowed to react with hydrazine hydrate to afford 2-hydrazinylpyrimidine derivative 5. Compound 5 was used as a key intermediate for a facile synthesis of the targets 6 and 7. In contrast, pyranone 8 was obtained by transformation of compound 5. Using as a precursor for the synthesis of new pyrazolo pyrimidine derivatives 9–10. The major incentive behind the preparation of these compounds was the immense biological activities associated to these heterocyclic derivatives. Conclusions The newly synthesized compounds (1–4) showed potent anti-inflammatory activities both in vitro and in vivo. They also exhibited promising antioxidant vitalities against α, α-diphenyl-β-picrylhydrazyl scavenging activity and lipid peroxidation. In conclusion, compound 1 showed a hopefully anti-inflammatory and antioxidant activities.

Keywords

• Pyrazolopyrimidine
• Thiophene
• Chalcone
• Pyrazol
• Pyranone
• Anti-inflammatory-antioxidant-cycloxygenase-5-LOX-DPPH