Alum-Catalyzed Domino Synthesis of 12-Substituted-8,9,10,12-tetrahydrobenzoxanthen-11-ones Under Solvent-Free Conditions

Abstract

Alum is found to catalyze efficiently the one-pot, three-component condensation of aldehydes, α/β-naphthol, and dimedone to afford various 12-substituted-8,9,10,12-tetrahydrobenzoxanthen-11-ones in excellent yields. The use of alum catalyst and the solvent-free conditions make this method simple, convenient, eco-friendly, and cost-effective.

GRAPHICAL ABSTRACT

Keywords:

• Alum
• domino
• multicomponent
• solvent-free
• tetrahydrobenzoxanthenones

Notes

^a Reaction condition: Benzaldehyde (1.0 mmol), β-naphthol (1.0 mmol), dimedone (1.0 mmol), and alum (10 mol%, 0.1 mmol), 120 °C, N₂ atmosphere, 30 min.

^b As revealed by TLC.

^c Isolated yield.

^a General reaction conditions: Aldehyde 1 (1.0 mmol), α/β-naphthol 2 (1.0 mmol), dimedone 3 (1.0 mmol, 0.140 g), and alum (10 mol%, 0.1 mmol, 0.047 g), 120 °C, N₂ atmosphere.

^b All the products were characterized by their physical and spectral data.

^c Isolated yields.

^d Literature reference of melting point.

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