• Bulletin of the Korean Chemical Society
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• v.33 no.4
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• pp.1154-1158
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• 2012

A room-temperature ionic liquid (RTIL) derived from 1,4-diazabicyclo[2.2.2]octane (DABCO) consisting of tetrafluoroborate anion, 1-butyl-4-(4-sulfonylbutyl)-1,4-diazoniabicyclo[2.2.2]octane hydrogen sulfate tetrafluoroborate ($[C_4DABCOC_4SO_3H][BF_4][HSO_4]$) was synthesized and catalytically evaluated in the synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes by cyclocondensation reaction of ${\beta}$-naphthol and aryl aldehydes. This novel RTIL with an acidic $SO_3H$ group showed high catalytic activity with good to excellent yields of the desired products in short reaction times. Moreover, the catalyst could be recovered and reused at least three times with only slight reduction in its catalytic activity.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2311-2315
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• 2011

Alumina supported polyphosphoric acid (PPA/$Al_2O_3$) was successfully prepared by impregnation of alumina support by polyphosphoric acid and characterized using FT-IR spectroscopy, the $N_2$ adsorption/desorption analysis (BET), thermal analysis (TG/DTG), and X-ray diffraction (XRD) techniques. The catalytic behavior of this new solid acid supported heterogeneous catalyst was checked in the synthesis of 14-aryl-14H-dibenzo[a, j]xanthenes by cyclocondensation reaction of ${\beta}$-naphthol and aryl aldehydes under solvent-free conditions. The results showed that the novel catalyst has high activity and the desired products were obtained in very short reaction times with high yields. Moreover, the catalyst can be easily recovered by filtration and reused at least three times with only slight reduction in its catalytic activity.

• Journal of the Korean Chemical Society
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• v.46 no.6
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• pp.541-544
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• 2002

Prepartion of the title compounds at 0-5$^{\circ}C$ is reported along with their AM1 SCF MO calculations. The advantage of this procedure is the hight purity of the produ cts.

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.35-36
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• 2011

• Journal of the Korean Chemical Society
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• v.53 no.4
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• pp.415-421
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• 2009

A convenient and practical synthesis of 1, 8-dioxo-octahydroxanthene derivatives using various aldehydes, 5, 5-dimethyl-1, 3-cyclohexanedione in water was successfully carried out in the presence of polyethylene glycol (PEG) as a catalyst. Simple work-up, clean products, high yields and water as a green solvent are the attractive features of this methodology.