Efficient synthesis of functionalized acenaphtho[1,2-b]indol-6b-ol derivatives

An efficient method for the synthesis of functionalized acenaphtho[1,2-b]indol-6b-ol derivatives were developed by the three-component reaction of acenaphthoquinone, barbituric acid, or N, N-dimethyl barbituric acid and aryl amines through sequential Knoevenagel / Michael / intramolecular N-cyclization sequences in ethanol. The reactions were carried out under catalyst-free and mild conditions. Advantages of this method include simple operation, catalyst-free, readily available starting materials, no need to column chromatography purification, and good to high yields (78 - 92 %). We confirmed the product by Fourier-transform infrared spectroscopy (FT-IR), Proton nuclear magnetic resonance (1H NMR), 13C nuclear magnetic resonance (13C NMR), and Mass spectrometry.