• Archives of Pharmacal Research
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• v.15 no.3
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• pp.224-228
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• 1992

Arylhydrazones of diethylacetondicarboxylate 3 was treated with formaldehyde to give 1 aryl-4, 5, 6-trihydropyridaine derivatives 4a-f Cyclization of compound 4a-f by hydroxylamine afforded [3, 4d] 1, 3, 4, 5-tetrahydropyridazine derivatives 5a-f. Also cyclization of compound 4c with semicarbazide gave 1-amidopyrazolo-5-one-1-aryl-3-carboxypyridazine 6. On the other hand compounds 3 reacted with ethylorthoformate to give diethyl-1, 4-dihydro-1-arylpyridazine-4one-2.5 dicarboxylate 7, which on treatment with hydrazine. Semicarbazide and thiosemicarbazide gave pyridazine, amido and thioamido derivatives. The spectral and antimicrobial data of these compounds 1-8 were studied.

• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.2978-2980
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• 2011

Enynals bearing an olefinic pendant were successfully cyclized via Huisgen-type [3+2] cycloaddition to the tetracyclic Pt-carbene complexes which would undergo insertion into a C-H bond of the ${\beta}$-position to afford the fused cyclopropane intermediates. Their tandem rearrangement afforded diverse types of spiranes depending on the tethered alkenes of the enynals.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.2003-2010
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• 2010

A new class of halobenzyloxy or alkoxy 1,2,4-triazoles and their hydrochlorides were synthesized through cyclization starting from commercially available phenylhydrazine. The structures were characterized by MS, IR and $^1H$ NMR spectra as well as elemental analyses. All the synthesized compounds were screened for their antibacterial activities in vitro against Staphylococcus aureus (ATCC29213), methicillin-resistant Staphylococcus aureus (N315), Bacillus subtilis, Escherichia coli (ATCC25922), Pseudomonas aeruginosa, Shigella dysenteriae, Eberthella typhosa, and antifungal activities against Candida albicans (ATCC76615), Aspergillus fumigatus by broth microdilution assay method. The results of preliminary bioassay indicated that 3-(2,4-difluorobenzyloxy)-1-phenyl-1H-1,2,4-triazole hydrochloride exhibited the best inhibitory activity with an MIC value of 56.25 ${\mu}M$ against P. aeruginosa superior to Chloramphenicol, and showed comparable activity with Chloramphenicol against E. coli (ATCC25922).

• Journal of the Korean Chemical Society
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• v.58 no.4
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• pp.366-376
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• 2014

Synthesis, structural characterization, and biological activity studies of novel pyrido[2,3-d]pyrimidines (10a-h, 11a-h) are described. Cyclization of cynoacetamides (4, 5) with malonitrile (7) and aldehyde (6a-h) via Hantzsch pyridine synthesis afforded cyanopyridones (8a-h, 9a-h), which on cyclization with formic acid under microwave conditions led to the final product. All the reactions are significantly faster and the isolated yields are remarkably higher in microwave conditions compared to the conventionally heated reactions. The compounds were tested in vitro for their antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtillus, Staphylococcus aureus, and Micrococcus luteus and antifungal activity against Trichphyton longifusus, Candida albicans, Microsporum canis, Fusarium solani. Compounds 10b, 10e, 11b and 11e exhibited good antibacterial and antifungal activities compared with standards.

• Bulletin of the Korean Chemical Society
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• v.25 no.2
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• pp.207-212
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• 2004

In this study, we attempted to prepare compounds with heterocyclic replacements for metabolically unstable esters of benzopyranyl indole-2-carboxylic esters, which showed good in vitro and in vivo cardioprotective efficacies possibly through the opening of mitochondrial ATP-sensitive potassium channel ($K_{ATP}$). Initially, we tried to construct indolin-2-yl-heterocycles using unprotected indoline-2-carboxylic acid, but the cyclization was proceeded with oxidation of the indoline ring to the indole, which didn't react with benzopyranyl epoxide. Thus we introduced N-Boc group to deplete the electron density of the indoline ring. We successfully prepared various indolin-2-yl-heterocycles by the cyclization of the building blocks including carboxamide, ${\beta}$-hydroxy amide, hydrazide, nitrile starting from N-Boc-indoline-2-carboxylic acid.

• Journal of the Korean Chemical Society
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• v.39 no.5
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• pp.408-413
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• 1995

A few t-amine substituted anilines and amides were synthesized and cyclized to pyrrolo[1,2-a]benzimidazole by heating in various solvents having different polarity. Subsequent nitration of cyclized compound followed by reduction and oxidation of resulting amine afforded quinone such as 7 in 14% yield. The formation of imidazole moiety by thermal cyclization was independent on the solvent polarity. The regiochemistry for the nitration of 4 was unambiguously determined by chemical transformation.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2153-2161
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• 2007

The transition metal-induced in situ generation of carbene complexes from alkynes having a carbonyl or imino group as a nucleophilic functionality has been investigated. These reactive carbenoid species are generated with high atom efficiency through a 6-endo-dig cyclization mode based on the electrocyclization of vinylidene complexes or a 5-exo-dig cyclization mode in π-alkyne complexes, and have been found to serve as versatile intermediates in catalytic carbene transfer reactions. Highlighted and reviewed in this account are the generation and preparation of pyranylidene, furylcarbene, pyrrolylcarbene, and vinylcarbene complexes and their application to [3,3]sigmatropic rearrangement of acylcyclopropylvinylidenes, catalytic cyclopropanation reactions, [2,3]sigmatropic rearrangement or condensation reactions via ylides, ring-opening and substitution reactions with heteroaromatic compounds, and catalytic isomerization of oligoynes.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.887-891
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• 2013

An efficient synthesis of 3-halofurans by the intramolecular cyclization of 2-(1-alkynyl)-2-alken-1-ones with cupric halide has been developed. A broad range of 3-chloro- and 3-bromofuran derivatives could be obtained in the present method in moderate to good yields. The 3-halofuran derivatives are potential synthetic intermediates for amplification of molecular complexity.

• Archives of Pharmacal Research
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• v.13 no.1
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• pp.9-13
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• 1990

4, 5-Diphenyl-2-mercaptiomidazole (I) was reacted with hydraziodyl halides IIa-d togive the S-alkyl derivatives III-a-d. Cyclization of IIIa-d afforded imidazo[2, 1-b]-thiazole derivatives Vla, b and VII. Treatment of 1 with a-chloroethylacetoaccetate (IV) gave ethyl 2(4, 5-diphenyl-2-imidazolinylthio)-3-keto-butyrate (V). Compound V coupled with benzendiazonium chloride to give the corresponding phenylhydrazo compound IIId. On heating V with polyphosphoric acid, cyclization took place and 2-acetyl-5, 6-diphenyl-imidazo [2, 1-b] thiazol-3-one (VIII) was obtained. The compound VIII was condensed with aromatic aldehydes to yield the cinnamoyl derivatives 1Xa, b. The antimicrobial activities of compounds IIIa-d, V, VIa, VII were examined.

• Applied Chemistry for Engineering
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• v.8 no.1
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• pp.39-48
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• 1997

The intramolecular cyclization of 1,1-bis-(3,4-dimethoxyphenyl)ethane was shown to take place upon anodic oxidation at carbon electrodes in acetonitrile or in a solvent-mixture containing dichloromethane, trifluoroacetic acid(TFA). Yields are low in the former solvent due to the fact that the cyclized product (9-methyl-2,3,6,7-tetramethoxyfluorene) is more easily oxidized than it's precursor and the oxidation product is not stable. In the presence of TFA, the cation radical derived from the oxidation of the cyclized product is stabilized thus, after reduction may be isolated with better yields.