• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.05a
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• pp.130-134
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• 2002

Polyol esters were synthesized by condensation reaction of polyols (PE and DIPE) and linear acids such as valeric acid, caproic acid, heptylic acid and caprylic acid. The structures of polyol esters were confirmed by gas chromatography. Hot tube test was used to measure thermal stability of polyol esters and its thermal properties depended on the structure of acid moiety contained in polyol esters.

• Tribology and Lubricants
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• v.18 no.5
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• pp.319-323
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• 2002

Polyol esters were synthesized by condensation reaction of polyols (PE and DiPE) and linear acids such as valeric acid, caproic acid, heptylic acid and caprylic acid. The structures of polyol esters were confirmed by gas chromatography. Hot tube test was used test was used to measure thermal stability of polyol esters and its thermal properties depended on the structure of acid moiety contained in polyol esters.

• YAKHAK HOEJI
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• v.47 no.5
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• pp.276-282
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• 2003

For the development of new synthetic method for unnatural amino acid esters, N-aryl phenylglycine Ο-alkyl esters 4a∼i were synthesized through esterification, bromination, C-N bond formation from commercially available phenylacetic acids. An efficient and practical reaction condition for esters 2a∼c was that the starting materials 1a∼c were refluxed in absolute methanol for 3 hours with catalytic concentrated hydrosulfuric acid. In addition, bromines 3a∼c were formated for 3h in dichloromethane at rt with N-bromosuccinimide. Bromines 3a∼c were also converted to 4a∼i through substitution of arylamines during refluxing for 24 hours in ethanol with triethylamine. Interestingly, ethyl esters 5a∼c were formed via transesterification reaction when the p-sulfamylanilino group was used as a nucleophile in ethanol solvent.

• Bulletin of the Korean Chemical Society
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• v.12 no.1
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• pp.97-101
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• 1991

Gas-phase pyrolyses of carbonate esters, ${\alpha}$- and ${\beta}$-hydroxy esters and ${\beta}$-hydroxy ketones have been studied theoretically by the AM1 MO method. Carbonate esters were found to decompose by two types of processes; in the reaction pathway involving an intermediate, the decomposition of the intermediate was rate-limiting, but direct pyrolyses were also possible via a six-membered cyclic transition state in which the methoxy oxygen attacks a hydrogen atom on the ${\beta}$-carbon. The hydroxy esters and ketones were found to decompose in a concerted process involving a six-membered cyclic transition state. Successive methylation on the ${\alpha}$- and ${\gamma}$-carbon led to an increase in the reactivity in agreement with experiments.

• Toxicological Research
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• v.16 no.2
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• pp.141-146
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• 2000

Phthalate esters are used extensively as a plasticizer in the manufacture of plastic products such as PVC bags and medical devices. Recently, phthalate esters have been shown to induce endocrine system mediated responses. However. only a Jew studies have been conducted for estrogenic activity of phthalate esters. In this study estrogenic activities of seven phthalate esters. butyl benzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), di-n-butylphthalate (DBP), diethylphthalate (DEP), di-n-pentylphthalate (DPP), di-n-propylphthalate (DPrP) and dicyclohexylphthalate (DCHP), were examined in vitro using E-screen assay and competitive binding assay. From the E-screen assay, BBP. DEHP. DBP and DEP showed weak estrogenic activity at the concentration of 5 $\mu\textrm{M}$. The relative proliferative effect (RPE) and the relative proliferative potency (RPP) were 50~70% and 0.01%. respectively, when compared with 500 pM of 17$\beta$-estradiol (E2). In competitive binding assay with the rat uterine estrogen receptor (ER), BBP and DEP showed weak binding potency ［(l/$10^4$~1/$10^5$ of E2］ while DEHP and DBP scarcely bound to ER. These results suggest that some phthalate esters have weak estrogenic activities in vitro.

• YAKHAK HOEJI
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• v.30 no.3
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• pp.121-127
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• 1986

Three new alkanol esters of d-2-(6-methoxy-2-naphthyl)propionic acid, NAPROXEN were synthesized by esterification of sodium naproxen with chloralcohols, such as 2-chloroethanol, 3-chloro-1, 2-propanediol and $\beta$-chloroethoxyethanol in dimethylformamide. These new esters were obtained with comparably high yield and identified by elemental analysis, UV, IR and NMR techniques.

• Journal of the Korean Chemical Society
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• v.8 no.3
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• pp.128-130
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• 1964

Fluorinated acid chlorides in the C$_3$ to C$_9$ range were reacted with diols prepared from terpene diacids to give good yields of potentially useful esters. These esters were shown to be of greater stability and low temperature properties than those prepared from fluorinated alcohols and corresponding terpene diacids by direct esterification.

• Journal of the Korean Chemical Society
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• v.37 no.9
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• pp.837-844
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• 1993

N-Arylmethylideneglycine N-oxide alkyl esters(1) were alkylated with alkyl halides in THF using lithium hexamethyldisilazide as a base, followed by hydroxylaminolysis to give N-hydroxy-${\alpha}$-amino acid esters(7).

• YAKHAK HOEJI
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• v.47 no.3
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• pp.130-134
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• 2003

For the development of new synthetic method for unnatural amino acid esters, N-aryl phenylglycine Ο-alkyl esters 4a∼i were synthesized through base-catalyzed hydrolysis of 1,5-diphenylhydantoins 1a∼b and Ο-alkylation in 16∼87％ yield. An efficient and practical route for final 4a∼i was that the starting materials 1a∼b were heated in dil-methanol for 30 minute using sodium hydroxide or potassium hydroxide and evaporated. In addition, reaction mixture were refluxed for 1 h in DMF. All synthetic process from hydantoin to N-aryl phenylglycine Ο-alkyl esters 4a∼i could be carried out in one-pot without isolation of intermediates.

• KSBB Journal
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• v.30 no.4
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• pp.197-201
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• 2015

Liquid chromatographic enantiomer separation of ${\alpha}$-amino acids and their methyl and ethyl esters as fluorenylmethoxycarbonyl (FMOC) derivatives was performed using a recently developed chiral column (Chiralpak IE) based on polysaccharide derivative under simultaneous UV detection and fluorescence detection. The degree of enantiomer separation of ${\alpha}$-amino acid esters as FMOC derivatives is generally higher than that of the corresponding ${\alpha}$-amino acids. Especially, ${\alpha}$-amino acid methyl esters showed the greatest enantioseparation. As this method developed in this study can be applied to determine the chemical and optical purity of ${\alpha}$-amino acids and esters, it is expected to be quite useful for their chiral separation using Chiralpak IE.