Uses of 2-Amino-5,6-dihydro-4H-cyclopenta [b] thiophene-3-carbonitrile in the Synthesis of Heterocyclic Compounds with Anticonvulsant, Behavioral and CNS Antidepressant Activities

The reaction of the cyclopenta[b]thiophene derivative 3 with phenylisothiocyanate4 gave thiourea derivative 5. The latter was reacted with the active methylene reagents 2a, b and 7 to give pyrimidine derivatives 6a, b and 8. N-Acylation of compound 3 was achieved via its reaction with acetic anhydride 9 to give the acetyl derivative 10. Compound 10 was utilized as a key for the synthesis of different heterocyclic compounds, where arylidene derivative 12 was obtained via its reaction with benzaldehyde11 and thienopyridone derivative 13 was obtained via its intramolecular cyclization using basic catalysis. Finally treatment of 10 with different activated carbonitriles2a, b or with hydrazine derivatives 15a, b afforded thienopyridone derivatives 14a,b and thienopyrimidine derivatives 17a,b, respectively. The newly synthesized compounds were tested for anticonvulsant, behavioral and CNS antidepressant activities.