Nucleophilic Addition/Electrocyclization Strategy toward Polyheterocyclic-Fused Quinoline-2-thiones in Green Solvent

A metal-free and base-free cyclization reaction of ortho-heteroaryl anilines with isothiocyanatobenzene for the synthesis of diverse polyheterocyclic-fused quinoline-2-thiones was developed in PEG-200. This protocol features green solvent, lack of requirement for a metal and base, short reaction time consumption, and facile isolation via simple filtration. Furthermore, this protocol is easy to scale up which demonstrates outstanding synthetic scalability.

Automated summary

A metal-free and base-free cyclization reaction was developed for the synthesis of diverse polyheterocyclic-fused quinoline-2-thiones. This protocol offers the advantages of using a green solvent, no requirement for a metal and base, short reaction time consumption, and facile isolation via simple filtration. Furthermore, it demonstrates outstanding synthetic scalability.