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

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.