• Bulletin of the Korean Chemical Society
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• v.33 no.6
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• pp.2023-2027
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• 2012

An efficient and practical synthesis of MBH adducts of aryl vinyl ketones was developed using DABCO and 4-nitrophenol as a proton donor. Addition of a proton donor and the use of excess amounts (3.0 equiv) of aldehydes were highly beneficial for the yields of MBH adducts of aryl vinyl ketones.

• Bulletin of the Korean Chemical Society
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• v.33 no.6
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• pp.1856-1860
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• 2012

$SnO_2/SiO_2$ nanocomposite has been synthesized by using sol-gel method. Prepared catalytic materials has been well characterized by using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmer-Teller (BET) surface area, and temperature-programmed desorption of ammonia ($NH_3$-TPD). $SnO_2/SiO_2$ nanocomposite catalyzed synthesis of 2-arylbenzothiazoles by the cyclocondensation of 2-aminothiophenol and aromatic aldehydes under reflux condition in 1:1 EtOH:$H_2O$. After completion of the reaction, catalyst can be recovered efficiently and reused with consistent activity.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2555-2558
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• 2009

The condensation of cyclic ketone with aromatic aldehydes in the presence of ammonium acetate under ethanol media affords the corresponding 5-aryl-7,8,13,14-tetrahydrodibenzo[a,i]phenanthridine with excellent yield. This mild and efficient procedure with high yield is also applied to the synthesis of 2,4-diaryl-6,7-benzo-3-azabicyclo- [3.3.1]nonan-9-ones and ${\alpha},{\alpha}{$’-bis(substituted benzylidene)cycloalkanones.

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1508-1512
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• 2013

A simple and efficient synthesis of 2,4,5-trisubstituted imidazoles was achieved via a one-pot three-component cyclocondensation of benzil, aromatic aldehydes, and ammonium acetate in the presence of a catalytic amount of tetrabutylammonium hexatungstate $[TBA]_2[W_6O_{19}]$ as a heterogeneous catalyst under thermal solvent-free conditions. The key features of this methodology are operational simplicity, high yields, short reaction times, and a recyclable catalyst with a very easy work up.

• Bulletin of the Korean Chemical Society
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• v.19 no.3
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• pp.314-319
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• 1998

One flask synthesis of dithienylmethane and difurylmethane is reported. The reaction of aldehydes with excess furan or thiophene affords the meso-phenyldithienylmethane (DTM) and meso-phenyldifurylmethane (DFM), respectively. The reaction is catalyzed with trifluoroacetic acid or with BF3·O(Et)2. An acyl group is selectively introduced in 1 and 9 position of difurylmethane and dithienylmethane by use of an acid chloride and tin (IV) chloride. The reduction of resulting 1,9-bisacyldifurylmethane or 1,9-bisacyldithienylmethane affords the corresponding 1,9-bis-diol. An acid catalyzed condensation of diol with meso-phenyldipyrromethane followed by oxidation with DDQ gives the porphyrins. The reaction resulted meso-5,10,15,20-tetraphenyl-21,22-dithiaporphyrin (SSNN) or 15-mesityl-5,10,20-triphenyl-21,22-dioxaporphyrin (OONN), respectively. The formation of small amount of meso-tetraphenylporphyrin (TPPH2) is also observed. The formation of TPP indicates that meso-phenyldipyrromethane is reversibly cleaved and form pyrrole and pyrrylbenzylcarbocation during the condensation. The proton nmr and electronic spectrum of the SSNN and OONN porphyrins are somewhat different from the previously synthesized meso-5,10,15,20-tetraphenyl-21,23-dithiaporphyrin (SNSN) or meso-5,10,15,20-tetraphenyl-21,23-dioxaporphyrin (ONON).

• Archives of Pharmacal Research
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• v.21 no.2
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• pp.147-152
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• 1998

Cinnamaldehydes and related compounds were synthesized from various cinnamic acids based on the $2^{I}$-hydroxycinnamaidehyde isolated from the bark of Cinnamomum cassia Blume. The cytotoxicity to human solid tumor cells such as A549, SK-OV-3, SK-MEL-2, XF498 and HCT15 were measured. Cinnamic acid, cinnamates and cinnamyl alcohols did not show any cytotoxicity against the human tumor cells. Cinnamaldehydes and realted compounds were resistant to A549 cell line up to 15 .mu.g/ml. In contrast, HCT15 and SK-MEL-2 cells were much sensitive to these cinnamaidehyde analogues which showed $ED{50} values 0.63-8.1{\mu}g/ml.$Cytotoxicity of the saturated aldehydes was much weak compared to their unsaturated aldehydes. From these studies, it was found that the key functional group of the cinnamaldehyde-related compounds in the antitumor activity is the propenal group.p.

• Archives of Pharmacal Research
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• v.28 no.11
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• pp.1205-1212
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• 2005

2-Thiouracil-5-sulphonic acid N-(4-acetylphenyl) Amide (1) was reacted with a series of aromatic aldehydes giving chalcones 2 (Claisen-Schemidt reaction), some of these chalcones were reacted with urea and thiourea giving pyrimidine-2-one and pyrimidine-2 thione derivatives respectively of the type 3a,b and 4a,b. In addition many chalcones were reacted with hydroxylamine hydrochloride giving isoxazoline derivatives 5a,b. They could also reacted with phenylhydrazine to give pyrazoline derivatives 5a,b, chalcones also were reacted withethylcyano acetate and/or malononitryl in pyridine giving pyran derivatives 7a,c and 8a,c. In another pathway chalcones were epoxidised by $H_{2}O_{2}$ giving epoxides 9a,c which in turn were reacted with phenylhydrazine giving 4-hydroxypyrazoline derivatives 10a,c. In another reaction chalcones were reacted with ethylcyanoacetate in presence of amm.acetate giving pyridone derivatives 11a,d which could be prepared also in exellent yield from compound 1 by its reaction with certain aromatic aldehydes and ethylcyanoacetate in presence of ammonium acetate. Finally, compound 1 was reacted with semicarbazide giving semicarbazone intermediate 12 which in turn was reacted with thionyl chloride giving thiadiazole derivative 13. The biological effects of some of the new synthesized compounds were also investigated.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2835-2840
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• 2010

A series of $MoO_3/CeO_2-ZrO_2$ catalysts with different Mo content (8 - 20 wt %) were prepared by simple co-precipitation followed by impregnation method and were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), energy dispersive spectroscopic (EDS) techniques. The prepared materials were tested for catalytic activity by the synthesis of benzimidazole derivatives using condensation of aromatic aldehydes and o-phenylenediamine by conventional and microwave method. Obtained results reveal that the catalytic activity increases with increase in Mo wt % loading. The best catalytic activity was obtained with 20 wt % $MoO_3/CeO_2-ZrO_2$. The particle size or crystallite size was estimated using Debye-Scherrer equation. After completion of reaction, the catalyst can be recovered efficiently and reused with consistent activity.

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1521-1524
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• 2013

N-Propylsulfamic acid supported onto magnetic $Fe_3O_4$ nanoparticles (MNPs-PSA) was used as an efficient and magnetically recoverable catalyst for synthesis of 2H-Indazolo[2,1-b]phthalazine-1,6,11(13H)-trione derivatives from the three-component, one-pot condensation reaction of phthalhydrazide, aromatic aldehydes and cyclic 1,3-diones, in good to excellent yields at $100^{\circ}C$ under solvent-free conditions. The catalyst was easily separated with the assistance of an external magnetic field from the reaction mixture and reused for several consecutive runs without significant loss of its catalytic efficiency. In order to compare, the synthesis of 2H-Indazolo[ 2,1-b]phthalazine-1,6,11(13H)-trione derivatives in the presence of catalytic amount of sulfamic acid (SA) under same reaction condition was also reported.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2724-2730
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• 2012

A new heterogeneous acidic catalyst was successfully prepared by impregnation of silica (Aerosil 300) by an acidic ionic liquid, named 1-(4-sulfonic acid)butylpyridinium hydrogen sulfate [$PYC_4SO_3H$][$HSO_4$], and characterized using FT-IR spectroscopy, the $N_2$ adsorption/desorption analysis (BET), thermal analysis (TG/DTG), and X-ray diffraction (XRD) techniques. The amount of loaded acidic ionic liquid on Aerosil 300 support was determined by acid-base titration. This new solid acidic supported heterogeneous catalyst exhibits excellent activity in the synthesis of 2-aryl-2,3-dihydroquinazolin-4(1H)-ones by cyclocondensation reaction of 2-aminobenzamide with aromatic aldehydes under solvent-free conditions and the desired products were obtained in very short reaction times with high yields. This catalyst has the advantages of an easy catalyst separation from the reaction medium and lower problems of corrosion. Recycling of the catalyst and avoidance of using harmful organic solvent are other advantages of this simple procedure.