부산대학교 도서관

Here, we described a facile method for synthesis of novel 1-piperidinyl and 1-piperazinyl-3-thioxo-6,7-dihydro-5H-cyclopenta[c]pyridine-4-carbonitrile compounds as well as the previously synthesized 1-morpholinyl derivative by the reaction of 3-amino-1-thioxo-1,5,6,7-tetrahydro cyclopenta[c]thiopyran-4-carbonitrile with piperidine, piperazine and morpholine, respectively through Dimorth rearrangement. A series of new 1-amino-2-substituted-5-morpholinyl-7,8-dihydro-6H-cyclopenta[d]thieno[2,3-c]pyridine was synthesized by the reaction of the morpholinyl cyclopenta[c]pyridine thione with α-halogenated carbonyl compounds namely: ethyl chloroacetate, chloroacetone and ω-bromoacetophenone via two synthetic routes. The ethyl 1-amino-5-morpholin-4-yl-7,8-dihydro-6H-cyclopenta[d]thieno[2,3-b]pyridine-2-carboxylate was utilized as a powerful precursor for the synthesis of novel heterocycles containing cyclopenta[d]thieno[2,3-c]pyridine moiety. Hydrazinolysis of the amino thienopyridine carboxylate ester with hydrazine hydrate 99% upon reflux under solvent-free conditions produced the corresponding amino-carbohydrazide, which was used as a versatile intermediate to prepare new heterocyclic systems. The chemical structures of all newly synthesized compounds were elucidated based on their elemental and spectral analyses. Furthermore, some of these compounds revealed promising anti-inflammatory activity using carrageenan-induced rat paw edema assay compared with indomethacin as a reference drug. [ABSTRACT FROM AUTHOR]