• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.367-375
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• 2011

Succinic acid ester derivatives have been used as additives for the base oil of metal working fluids and pressure working oils. In this paper, a series of succinic acid alkyl half-esters were synthesized with over 97% yields by ring-opening reaction of succinic anhydride and fatty alcohol and were soluble in 100 N base oil within 1 wt% concentration. The structures and purities of ester derivatives were confirmed by $^1H-NMR$ and FT-IR spectrum and GC analysis. Anti-corrosion properties of the esters in sea water were evaluated through ASTM D665 method and weight loss method and compared to that of succinic alkyl esters without carboxylic acid group in the molecule. As the results, anti-corrosion properties of succinic acid alkyl half-esters with carboxylic acid group were better than those of succinic acid alkyl esters without carboxylic acid group. And, Anti-corrosion properties of the esters with a shorter alkyl chain of high concentration showed better performance than those with longer alkyl chain of low concentration. Inhibition efficiency % (IE%) of the esters was over 95% in the concentration of 80 ppm and corrosion rate (CR) was below 0.3 mm/year at the same concentration. Thus, the corrosion properties of succinic acid alkyl half-esters result from the carboxylic acid groups in molecules.

• Korean Chemical Engineering Research
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• v.58 no.3
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• pp.474-479
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• 2020

The etching solution for slimming of glass substrates was manufactured and HF was used as the main ingredient of wet etching solutions. Various types of strong acids such as HCl, HNO₃, H₂SO₄, amino acids and carboxylic acids such as citric acid, and etched solutions, respectively, were used to measure the etching rates and changes in surface shape of the glass. Regardless of the type of strong acids, the etching rate of the glass increased linearly as the added amount increased, and the sludge removal effect of the glass surface was also shown. The etching solution containing HCl showed more efficient results than other strong acids in the etching rate and the effect of removing sludge. The addition of carboxylic acid did not significantly affect the variation of etching rate, but had the effect of removing sludge. However, if amino acids were added, changes in etching rate and sludge removal were not significant.

• YAKHAK HOEJI
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• v.38 no.2
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• pp.197-201
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• 1994

A number of 7-[(3-methylthio or methylthiomethyl)pyrrolidiny]qui nolone-3-carboxylic acids were synthesized by condensation of 7-fluoro substituted quinolone-3-carboxylic acid with 3-methylthiopyrrolidine or 3-methylthiomet hylpyrrolidne. 3-Methylthiopyrrolidine or 3-methylthio-methylpyrrolidine which was prepared from N-benzyl-3-hydroxy pyrrolidine or 3-hydroxymethylpyrrolidine. The in vitro antimicrobial activity of them were tested against twenty species of Gram-positive or Gram-negative microorganisms. It showed remarkable antibacterial activity, particularly against Gram-positive microorganisms. Among those 1-cyclopropyl-6,8-difluoro-7-(3-methylthiomethy-lpyrrolidinyl)-1,4-d ihydro-4-oxo-3-quinolinecarboxylic acid(7d) and 1-cyclopropyl-6- fluoro-8-chloro-7-(3-methylthiomethyl pyrrolidinyl)-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid (7f) showed the most potent in vitro antibacterial activity.

• YAKHAK HOEJI
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• v.57 no.6
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• pp.426-431
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• 2013

In our previous studies, 6-hydroxy-7-methoxychroman-2-carboxylic acid N-phenylamide (KL-1156) was identified as a good inhibitor of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) activation. In continuation of our study, we describe the structure-activity relationship of chroman derivatives containing N-arylalkyl groups and their NF-${\kappa}B$ inhibitory activities. In addition, inhibitory effects of cell proliferation are evaluated against human cancer cell lines (NCI-H23 and PC-3). The most active compounds 3i and 3j contained diphenylethyl and diphenylpropyl side chain on amide nitrogen.

• YAKHAK HOEJI
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• v.38 no.6
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• pp.677-682
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• 1994

A number of 7-[3-hydroxy-(4-methylthio or 3-methylthiomethyl)pyrrolidinyl]quinoline-3-carboxylic acids were synthesized by condensation of 7-fluoro substituted quinoline-3-carboxylic acid with 3-hydroxy-4-methylthiopyrrolidine or 3-hydroxy-4-methylthiomethylpyrrolidine. The in vitro antimicrobial activity of them were tested against twenty species of Gram-positive or Gram-negative microorganisms. It showed remarkable antibacterial activity, particularly against Gram-positive microorganisms. Among those 1-cyclopropyl-5-amino-6,8-difluoro 7-(3-hydroxy-4-methylthiomethylpyrrolidinyl)-1,4-dihyd ro-4-oxo-3-quinolinecarboxylic acid(12d) and 1-cyclopropyl-6-fluoro-8-methoxy-7-(3-hydroxy-4-methylthiometby1pyrrolinyl)-1,4-dihydro-4-oxo-3-quinolinocarboxylic acid(12g) showed the most potent in vitro antibacterial activity, and 12d showed better antibacterial activity against MRSA compared to ciprofloxacin and sparfloxacin.

• YAKHAK HOEJI
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• v.56 no.3
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• pp.186-190
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• 2012

Nuclear factor-${\kappa}B$ (NF-${\kappa}B$) has been considered as one of the major targets for therapeutic agents of diverse human diseases. In the previous studies, 6-hydroxy-7-methoxychroman-2-carboxylic acid N-phenylamide (KL-1156) and chroman-2-carboxylic acid N-(4-chlorophenyl)amide were identified as good inhibitors of NF-${\kappa}B$ activation. In this continuous study, we describe the synthesis and NF-${\kappa}B$ inhibitory activities of chroman derivatives containing N-heteroaryl groups for exploration of SAR (structure-activity relationship). In addition, inhibitory effects of cell proliferation are evaluated against human cancer cell lines (NCI-H23 and PC-3).

• YAKHAK HOEJI
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• v.38 no.5
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• pp.520-524
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• 1994

A number of 7-[(3-methylthio or methylthiomethyl)-3-pyrrolinyl] quinolone-3-carboxylic acids were synthesised by condensation of 7-fluoro substituted quinolone-3-carboxylic acid with 3-methylthio-3-pyrroline or 3-methylthiomethyl-3-pyrroline. The in vitro antimicrobial activity of them were tested against twenty species of Gram-positive or Gram-negative microorganisms. It showed remarkable antibacterial activity, particularly against Gram-positive microoganisms. Among those 1-cyclopropyl-6,8-difluoro-7-[(3-methylthiomethyl) -3-pyrrolinyl]-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid(12a) and 1-cycl opropyl-6-fluoro-8-chlore-7-[(3-methylthiomethyl)-3-pyrrolinly]-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid(12b) showed the most potent in vitro antibacterial activity.

• Journal of the Korean Chemical Society
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• v.37 no.4
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• pp.431-441
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• 1993

The structure and reactivity of ${\pi}$-and metallacycle form in the bis(trimethylphosphine) palladium(0) complexes with acrylic acid, methacrylic acid, crotonic acid(A group) and 3-butenoic acid, 4-pentenoic acid(B group) have been investigated by Molecular Mechanics and Extended Huckel Molecular Orbital method. The calculation shows that A groups with large value of frontier electron density of HOMO and LUMO produce $\pi-complexes$ instead of metallacycle. But B groups with small value of frontier electron density of LUMO, especially 3-butenoic acid, form stable metallacycle. Moreover the methyl-substituted five-membered compared with the six-membered metallacycle is energetically stable conformation.

• Journal of the Korean Chemical Society
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• v.32 no.2
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• pp.144-148
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• 1988

A novel synthetic route to 1,4-dihydropyridine mono carboxylic acid derivatives is described. Allyl methyl 2,6-dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3, 5-dicarboxylate (IV) was treated with $Pd(OAc)_2$ in dioxane for 30 min at 110$^{\circ}C$ with reflux to give the mono acid compound(V) in 94% yield. The mono acid intermediate was converted to 2-(N-benzyl-N-methylamino)ethyl methyl 2,6-dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3, 5-dicarboxylate (VII) (Nicardipine) and their derivatives in 70~85% yield.

• Korean Journal of Materials Research
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• v.7 no.11
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• pp.957-963
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• 1997

PVC 핏치를 산소분위기에서 안정화시킬 때 발생되는 화학반응 기구를 열중량 분석 및 FT-IR을 이용하여 규명하였다. PVC 핏치를 안정화시킬 \ulcorner 초기에 가속화현상이 이러나서 핏치내에 반응성이 강한 메칠기(-CH/ sub 3/)나 메칠렌기(-CH$_{2}$-)등이 산소와 반응하여 카보닐기(C=O)를 생성하면서 급격한 무게증가 현상이 발생하였다. 이때의 생성물들은 알데히드(aldehyde), 케톤(ketone), 알코올(alcohol)이며, 물 (H$_{2}$O)이 부산물로 발생된다. 이 가속화 현상에 의해 핏치내의 메칠기와 메칠렌기는 안정화 초기단계에서 대부분 산화되어 없어졌다. 안정화시간이 길어짐에 따라 생성된 알데히드나 일차 알코올의 산화가 발생하여 카르복실산(carboxylic acid)을 생성하고, 에테르 결합도 생성되었다. 이때에도 무게증가 현상이 발생하지만, 초기의 급격한 무게증가와는 달리 그 증가속도가 느리고, 시간이 경과함에 따라 증가속도는 더욱 느려졌다. 그리고, 안정화온도가 높고 안정화시간이 긴경우에는,카르복실산들의 탈수반응으로 인한 방향족 무수화물(aromatic anhydride)이 생성되었다. 29$0^{\circ}C$에서 24시간 안정화시킨 경우, 무게감소가 발생했는데, 이것은 카르복실산의 탈카르복실화(decarboxylation)반응에 의해 CO$_{2}$가 발생되었기 때문이다. 그리고, 안정화 온도가 높을수록 안정화에 무게증가의 최대값과 방향족 무수화물이 발생되는 무게증가 값이 작아지고, 안정화 초기단계에서 나타나는 가속화 현상의 구간도 짧아졌다.