• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2324-2328
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• 2007

Organic fluorine chemistry produces many useful products. This paper elucidates the reaction of ethyl-4,4- difluoro-2-iodo-5-oxo-5-phenylpentanoate (2) with primary amines in a one-pot scheme. The reaction produced a series of β-fluoropyrrole derivatives at ambient temperatures. In this reaction, the less bulky the primary amine the higher was the resultant yield. When (2) and aqueous methylamine (40%) were allowed to react below 0 oC, 5-(ethoxycarboxyl)-1-methyl-3,3-difluoro-2-hydroxy-2-phenylpyrrolidine, an intermediate molecule for 2-ethyl-4-flouro-1-methyl-5-phenylpyrrole-2-carboxylate (5), was isolated first. Then, (5) reacted with hydroperchloric acid and acetic anhydride to form 5-(ethoxycarboxyl)-1-methyl-3,3-difluoro-2- phenylpyrrolinium perchlorate (6), which was converted to 2-ethyl-4-flouro-1-methyl-5-phenylpyrrole-2- carboxylate gradually in the presence of a base. Our experiments demonstrate that the formation of 2-ethyl-4- flouro-1-methyl-5-phenylpyrrole-2-carboxylate occurs via both one-pot schemes and stepwise pathways, depending on the reaction conditions. The isolation and characterization of the isolated intermediate (6) suggest an anionic pathway for this reaction.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.617-621
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• 2014

An efficient and selective method for the synthesis of ethyl 2-amino/aryloxy-3-aryl-4-oxo-5-phenyl-4,5-dihydro-3H-pyrrolo[3,2-d]pyrimidine-7-carboxylate derivatives has been developed. The main process involved the reaction of diethyl 1-phenyl-3-((triphenylphosphoranylidene)amino)-1H-pyrrole-2,4-dicarboxylate and aromatic isocyanates, followed by addition of amines/phenols in the presence of catalytic amount of sodium ethoxide or solid potassium carbonate.

• Journal of Life Science
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• v.16 no.2 s.75
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• pp.206-212
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• 2006

In order to synthesize novel anticonvulsants, we researched that the reactions of diamines with 2,5-dimethoxytetrahydrofuran and 1,3-acetonedicarboxylic acid. The reaction of ethylenediamine with 2,5-dimethoxytetrahydrofuran and 1,3-acetonedicarboxylic acid afforded 8-(2-pyrrol-1-yl-ethyl)-8-aza-bicyclo[3,2,1]octan-3-one (yield; 5.0%) and 1,2-di-(8-aza-bicyclo[3,2,1]octan3-onyl)ethane (yield; 17.0%). In case of 1,3-diaminopropane, 8-(3-pyrrol-1-yl-propyl)-8-aza-bicyclo[3,2,1]octan-3-one(yield; 6.0%) and 1,3-di-(8-aza-bicyclo[3,2,1]octan-3-onyl)propane (yield; 21.0%) were obtained. In case of 1,8-diaminooctane, 8-(8-pyrrol-1-yl-octyl)-8-aza-bicyclo-[3,2,1]octan-3-one (yield; 2.6 %) and 1,8-di-(8-aza-bicyclo[3,2,1]octan-3-onyl)octane (yield; 24.9%) were obtained. In diaminobenzene reactions, synthetic yields of 8-aza-bicyclo-[3,2,1]octan-3-one derivatives were higher than those of pyrrole derivatives because re actions were done under room temperature. The longer the carbon chain of diaminoalkane is, the more reactive N atom is due to more electron donating effect, and the less steric hindrance around the carbon gave the higher chemical yields. The reaction of p-phenylenediamine as a diaminobenzene with 2,5-dimethoxyte-trahydrofuran and 1,3-acetonedicarboxylic acid produced p-dipyrrolylbenzene (yield; 4.0%), 8-(4-pyrrol-1-yl-phenyl)-8-aza-bicyclo[3,2,1]octan-3-one (yield; 12.0%), and 1,4-di-(8-aza-bicyclo[3,2,1]octan-3-onyl)benzene (yield; 59.0%). In case of m-phenylenediamine, 8-(3-pyrrol-1-yl-phenyl)-8-aza-bicyclo[3,2,1]octan-3-one(yield; 2.0%) and 1,3-di-(8-aza-bicyclo[3,2,1]octan-3-onyl)benzene (yield ; 28.0%) were obtained. But, synthesis of 1,2-di-(8-aza-bicyclo[3,2,l]octan-3-onyl)benzene by treatment of o-phenylenediamine was not successful, presumably due to the steric hindrance of 8-aza-bicyclo-[3,2,1]octan-3-one rings.

• Bulletin of the Korean Chemical Society
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• v.25 no.12
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• pp.1840-1844
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• 2004

The mass spectra of benzophenones, 2-benzoylthiophenes, 2-benzoylpyrroles, and 2-benzoylfurans which have substituents at the m- and p-positions of the benzoyl ring were analyzed to find correlations against the Hammett substituent parameter ${\sigma}\;and\;{\sigma}^+$. The slopes of the plots of the intensities of the fragments from the heterocycles against those of the benzene gave sets of meaningful values for the indices of aromaticity of the heterocycles: benzene 1.00; thiophene 0.94, pyrrole 0.82, and furan 0.74.

• Bulletin of the Korean Chemical Society
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• v.19 no.2
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• pp.183-188
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• 1998

Incorporation of metalloporphyrins into polypyrrole (PPy) film was achieved either by electropolymerization of pyrrole in the presence of metal-tetra(sulfonatophenyl)porphyrin anion (MTSPP, M=Co, Fe) or by metalizing hydrogenated tetra(4-sulfonatophenyl)porphyrin anion (H2TSPP) doped into PPy through ion-exchange. Electrochemical reduction of oxygen on the PPy doped with metallo porphyrin (PPy-MTSPP) was studied in acidic and basic solutions. Oxygen reduction on PPy-MTSPP electrodes appeared to proceed through a 4-electron pathway as well as a 2-electron path. In acidic solutions, the overpotential for O2 reduction on PPy-CoTSPP electrode was smaller than that on gold by about 0.2 V. In basic solutions the overpotential of the PPy-CoTSPP electrode in the activation range was close to those of Au and Pt. The limiting current was close to that of Au. However, polypyrrole doped with cobalt-tetra(sulfonatophenyl)porphyrin anion (PPy-CoTSPP) or with iron-tetra(sulfonatophenyl)porphyrin anion (PPy-FeTSPP) was found to have limited potential windows at high temperatures (above 50 ℃), and hence the electrode could not be held at the oxygen reduction potentials in basic solutions (pH 13) without degradation of the polymer.

• Bulletin of the Korean Chemical Society
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• v.20 no.3
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• pp.276-280
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• 1999

The different core-modified porphyrins 21-thia-23-carba-12-aza-5,10-dimesityl-15,20-diphenylporphyrin (6), and their N(12)-methyl derivatives (8) were synthesized by acid-catalyzed [3+1] condensation of the corresponding 16-thia-5,10-dimesityltripyrromethanes and 2,4-bis[(α-hydroxy-α-phenyl)methyl]pyrrole. Spectroscopic evidence indicates the existence of two different tautomeric forms at room temperature in porphyrin (6). A third form of tautomer was observed when the temperature was lowered to 223 K. The most stable tautomer is one in which the nitrogenic proton resides outside the core of the macrocycle. The ratio of the three different tautomers (outer N-H/ two inner N-H, i.e. 6/12/13) was 1/l/0.5 in the case of (6) while the ratio of 1/l/0.3 was observed in the case of (10). In the case of 21-oxa-23-carba-12-aza-5,10,15,20-tetraphenylporphyrin (7), the only stable tautomeric form observed by 1H NMR was the one that nitrogenic proton resides inside the core on

• Journal of the Korean Chemical Society
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• v.35 no.5
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• pp.569-574
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• 1991

Six free base porphyrins were synthesized by reacting pyrrole with benzaldehyde or its derivatives and then reacted with metal chlorides to prepare corresponding metal complexes. In addition, polymer-bonded porphyrins were synthesized by treating chloromethylated styrene-divinyl benzene (1%) copolymer beads with meso-tetra (p-aminophenyl)porphyrin (TNPP) solution and then treated with cupric chloride to obtain Cu(Res-NH-TPP-$NH_2$). The porphyrin compounds were characterized by visible, inffrared and electron spin resonance spectral analyses. The metal contents of metalloporphyrins were determined by atomic adsorption spectrophotometry. The synthesized porphyrin compounds were subsequently examined for their catalytic strength and found the activity to increase in the following order: free base porphyrins; metalloporphyrins; polymer-bonded metalloporphyrin. Among metalloporphyrins, Cu-TNPP showed the greatest catalytic power.

• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1706-1719
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• 2020

The objective of this study was to optimize the conditions for enhancing the antioxidant properties of sword bean (Canavalia gladiata) as a coffee substitute in two processing methods, roasting and grinding. The optimum conditions for removing off-flavor of the bean and maximizing functionality and efficiency were light roasting and cryogenic grinding (< 53 ㎛). In these conditions, extraction yield was 16.75%, total phenolic content (TPC) was 69.82 ± 0.35 mg gallic acid equivalents/g, and total flavonoid content (TFC) was 168.81 ± 1.64 mg quercetin equivalents/100 g. The antioxidant properties were 77.58 ± 0.27% for DPPH radical scavenging activity and 58.02 ± 0.76 mg Trolox equivalents/g for ABTS radical scavenging activity. The values for TFC and ABTS radical scavenging activity were significantly higher (p < 0.05) than in other conditions, and TPC and DPPH radical scavenging activity were second highest in lightly roasted beans, following raw beans. HS-SPME/GC-MS analysis confirmed that the amino acids and carbohydrates, which are the main components of sword bean, were condensed into other volatile flavor compounds, such as derivatives of furan, pyrazine, and pyrrole during roasting. Roasted and cryogenically ground (cryo-ground) sword beans showed higher functionality in terms of TFC, DPPH, and ABTS radical scavenging activities compared to those of coffee. Overall results showed that light roasting and cryogenic grinding are the most suitable processing conditions for enhancing the bioactivity of sword beans.

• YAKHAK HOEJI
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• v.36 no.2
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• pp.150-158
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• 1992