Synthesis and biological activity of pyrazolothienotetrahydroisoquinoline and [1,2,4]triazolo[3,4-a]thienotetrahydroisoquinoline derivatives

1-Hydrazino-3-thioxo-5,6,7,8-tetrahydroisoquinoline-4-carbonitrile (3) was subjected to react with bifunctional compounds namely: acetylacetone, ethyl cyanoacetate, ethyl benzoylactate, diethylmalonate and ethyl acetoacetate to produce pyrazololthienotetrahydroisoquinoline derivatives 6–11. Also, heating of compound (3) with formic acid afforded triazolothienotetrahydroisoquinoline compound 5 which reacted with α-halogenated compounds to afford compounds 13a–e. Compound 13c when heated with triethylorthoformate afforded triazolo derivative 14. Also, compound 6 was used for synthesizing compounds 18–20. Representative compounds of the synthesized triazolo and pyrazolothienotetrahydroisoquinoline products were tested and evaluated as antimicrobial agents.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► The aim of this work in this research is to synthesize new heterocyclic compounds. ► The new heterocyclic compounds contain thienotetrahydroisquinoline moiety namely: triazole, pyrazole and pyrimidine. ► Some of these compounds proved that they have antibacterial and antifungal activities.