Substituted Quinolinones, Part 14: Synthesis of Novel Dispiro(heterocycle-N,2′-[1,3]dithietane-4′,3″-quinolinedione) Derivatives Under PTC Conditions

Abstract

The four-membered spiro-heterocycles ethyl cyano(1-methyl-2,4-dioxospiro{1,3-quinoline-3,4′-[1,3]dithietane}-4′-ylidene)-acetate 2a, -malononitrile 2b, -acetylacetone 2c, and thiazetidine isomer 3 were prepared under phase transfer catalysis (PTC) conditions. The thermal treatment of dithietanes 2a–c led to the bis-quinolinyl sulfide 4. Some interesting nucleophilic additions followed by cyclization reactions were carried out with the dithietane 2a to give the corresponding novel dispiro derivatives 5–8, 10–13, and 15.

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GRAPHICAL ABSTRACT

Keywords:

• Dispiro-heterocycles
• 1,3-dithietane
• phase transfer catalysis
• quinolinone

Acknowledgements

Dedicated to the memory of the late Professor Ahmed K. El-Shafie.