• Proceedings of the PSK Conference
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• 2002.10a
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• pp.340.3-341
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• 2002

During the research for the development of antitumor agents. we found the 3-arylisoquinoline derivatives exhibited potent cytotoxicity against human tumor cell lines. For extending our study on these compounds. indeno［1.2-c］isoquinolines were chosen as the next research target due to previous studied data of the compounds that showed potent topoisomerase I inhibition activity as well as cytotoxicity against many kinds of tumor cell lines. Retrosynthetic consideration of indeno[1.2-d]isoquinolines indicates that the coupling of o-methyltoluamide with o-hydroxymethylbenxonitrile might afford 3-arylisoquinoline which could be translerred to the aldehtde. Indeno [1.2-c]isoquinolines can be formed by and inframolecular ring cyclization method. Various derlvatives of this compound including 11-alkoxy-6-methyl-6H. 11H-indeno[1.2-c]isoquinolin-5-one and biological activity will be presented with the docking model with topisomerase 1 enzyme.

• Archives of Pharmacal Research
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• v.17 no.4
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• pp.278-280
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• 1994

1,5-diketones(3) undewent cyclization to 4H-pyrano[3,2-d]pyrazoles (4a-d),4H-piperidino[3, 2-d]pyrazole (5) and pyrazolo[5,4-d]thiopyran (6) upon treatment with P/sub 2/O/sub 5/, CH/sub 3/COONH/sub 4/ and /or P/sub 2/S/sub 5/. Moreover, treatment of (4) with CH/sub 3/COONH/sub 4/ and/or P/sub 2/S/sub 5/ afforded (5) and (6). The structures of the hitherto unknown ring systems have been confirmed by analytical and spectral data.

• Bulletin of the Korean Chemical Society
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• v.24 no.3
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• pp.357-362
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• 2003

The pathway producing imide ring closure during the thermal imidization of poly(amic acid) (PAA) was investigated in detail using a new analytical method, two-dimensional (2D) Raman correlation spectroscopy. The signs of the cross peaks in synchronous spectra provided evidence of the thermal imidization of PAA into PI as the heating temperature increased. The signs of the cross peaks in asynchronous spectra suggested that the imide-related modes changed prior to the amide or carboxylic mode, which indicates that cyclization occurred before the amide proton was abstracted.

• Bulletin of the Korean Chemical Society
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• v.29 no.2
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• pp.357-362
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• 2008

A method for synthesizing o-carborane substituted tetrahydroisoquinolines containing a polar functional group such as sulfamide, sulfonic, or phosphoric acid on the nitrogen atom of the piperidine ring, starting from arylethylamine, N-(2-arylethyl)sulfamide, N-(2-arylethyl)sulfamic acid or 2-arylethylamidophosphate, is described. In vitro studies showed the desired compounds 10, 15, 19, and 25 synthesized accumulate to high levels in B-16 melanoma cells with low cytotoxicity.

• Archives of Pharmacal Research
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• v.23 no.4
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• pp.329-331
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• 2000

4-(p-Chlorophenyl)tetralone (6) and 7-chloro-5-(p-chlorophenyl)tetralone (9) are key intermediates for the development of benzazepinone derivative haftens. These compounds could be synthesized from 4-phenyltetralone derivatives by triflic acid catalyzed Friedel-Crafts reaction. The reaction mechanism of Friedel-Crafts alkylation/acylation with lactones in triflic acid is presented. According to our tentative research, ring opening of protonated lactone (2) occurs in alkyl cleavage and the rate of the reaction is not dependent on concentration of triflic acid. So, alkylation of lactone in Friedel-Crafts reaction is presumed to be $A_{AL}$ 1. In second step, intramolecular acylation of the intermediates 4 to 6, 4 can be transformed to a triflic acid-carboxylic anhydride and then the cyclization is undergone after leaving of the triflate anion.

• Bulletin of the Korean Chemical Society
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• v.24 no.10
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• pp.1429-1432
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• 2003

A novel fused thiouracil containing a heterocyclic ring system, dipyrimidinopyridine (3), has been prepared through the cyclization of compound 2. Compound 2 was formed by the formylation of 6-amino-2-thiouracil 1, pyrazolopyrimidines 8-10 via the heating of 6-arylhydrazono-2-thiouracils 5-7, compound 11, using Vilsmeier reagent with compound 4, pyrazolylpyrimidine 12, indolodiazinopyrimidine 14 and pyridazinopyrimidine 15. Pyridazino-pyrimidine 15 was formed by the condensation of compound 4 with acetylacetone, isatin and benzyl, respectively.

• Bulletin of the Korean Chemical Society
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• v.17 no.1
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• pp.29-33
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• 1996

Mono-, or di-substituted chlorodicyanovinyl benzene compound was reacted with an excess amount of ethylenediamine to give corresponding imidazoline product with high reaction yield. This reaction occurs by stable imidazoline ring-forming process through nucleophilic attack of terminal amine on the enaminonitrile adduct, the reaction intermediate, toward electropositive enamine carbon, which is accompanied by the release of neutral malononitrile moiety. The similar reaction with 1,2-phenylenediamine produced stable enaminonitrile-amine adduct at lower temperature which could be cyclized intramolecularly to thermally stable benzimidazole at elevated temperature in solution or in solid state. From the difunctional compound of both reactants, poly(enaminonitrile-amine) could be prepared as a new soluble precursor polymer for well-known polybenzimidazole (PBI). The thermal cyclization reaction accompanying the release of malononitrile molecules was studied using thermalanalysis and infrared spectroscopy.

• Journal of the Korean Magnetic Resonance Society
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• v.22 no.4
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• pp.115-118
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• 2018

Dipyrromethane 2 functionalized with 3-chloropropyl group on the meso carbon undergoes an unusual intramolecular electrophilic aromatic substitution reaction in the presence of $NaN_3$ instead of a simple nucleophilic substitution reaction. As a result, a new chiral dipyrromethane 1 was synthesized. In this reaction, the ${\beta}$-carbon of the pyrrole ring functions as a nucleophile while the carbon next to the chlorine atom acts as an electrophile. Interestingly, this reaction progresses even in the absence of an acid catalyst. Compound 1 was fully characterized by $^1H-^1H$ and $^1H-^{13}C$ COSY NMR spectroscopic analyses and the high resolution EI mass spectrometry.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.344.2-344.2
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• 2002

Sophoricoside analogs are natural isoflavonoids isolated from fruits of Sophora japonica L. and exhibited an inhibitory effect on IL -5. Many synthetic variations on isoflavonoids has been reported. but relatively few examples of quinolone analogs have been described. As part of our endeavor to develop novel and effective IL-5 inhibitor, we have synthesized azaisoflavones by cyclization of the key intermediate, 2'-aminochalocone obtained from substituted aniline. The synthesized azaisoflavones were evaluated for their inhibitory activtities on IL-5 comparing with natural Sophoricoside analogs. None of the azaisoflavones showed promixing inhibitory effects In the assay. Nevertheless. assay data Indicated that 5.7-phenolic hycroxy groups on the A-ring and alkyl subsitiuent on N1 seemed to play an importnt role in the IL-5 bioassay.

• YAKHAK HOEJI
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• v.27 no.3
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• pp.185-205
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• 1983

Penicillins and cephalosporins are biosynthesized from L-.alpha.-aminoadipic acid, L-cysteine and L-valine. A tripeptide, LLD-$\delta$-($\alpha$-aminoadipyl)cysteinylvaline(LLD-ACV) was isolated from fermentation broths of Cephalosporium acremonium as well as of Penicillium chrysogenum and it was proved that the LL-$\delta$-($\alpha$-aminoadipyl cysteine was formed first in mycelia, to which valine would be connected to give LLD-ACV. However, several points are still unsolved; first, what mechanism is involved in the configurational change from L-valine to D-valine, second, what kind of cyclization mechanism gives a $\betha$-lactam ring and a thiazolidine ring and third, what is the pathways for the ring expansion from penicillins to cephalosporins. At present, it seems clear that LLD-ACV is cyclized to give isopenicillin N, which is transformed to penicillin N and further to cepbalosporin C. Other hydrophobic penicillins, including benzyl penicillin and penicillin V, are formed from isopenicillin N by acyl-exchange reactions catalyzed by penicillin transferase, rather than by acylation reaction on 6-aminopenicillanic acid(6-APA), which was isolated from the fermentation broth of P. chrysogenum and which would be formed by hydrolysis of $\delta-(\alpha$-amincadipyl)amido moiety at the C-6 position in isopenicillin N or penicillin N by penicillin acylase. Acylation of 6-APA is catalyzed also by penicillin acylase, but the reaction is proved not to be involved in penicillin biosynthesis. Understanding the biosynthesis of penicillins and cephalsoporins would provide solutions to increase in fermentation yields of penicillins, especially of cephalosporins and a solution to biological production of 7-aminocepbalosporanic acid (7-ACA) which is of importance in pharmaceutical industry. Still regulation mechanisms in penicillin and cephalosporin biosynthesis are unveiled at all.