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
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.
Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/lsyc.