• YAKHAK HOEJI
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• v.33 no.2
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• pp.80-86
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• 1989

2,6-Dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-methyl 5-(2'-phenylsulfinyl) ethyl ester (10) or 2,6-Dimethyl-4-(2' or 3'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-alkyl 5-(2-methylsulfonyl) ethyl ester (14a, b, c) were hydrolyzed by treatment with NaOH in aqueous EtOH solution to give 2,6-Dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid monomethyl ester (4b), 2,6-Dimethyl-4-(2'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid monomethyl ester (4c) and 2,6-Dimethyl-4-(2'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid monoisopropyl ester (4d) in 80 -90% yield. By the same procedure, 2,6-Dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3,5-bis (2'-methylsulfonyl) ethyl ester (15) gave 2,6-Dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid (4e) in 96% yield.

• Proceedings of the PSK Conference
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• 2003.10a
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• pp.70-70
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• 2003

In mammalians, ketone bodies (acetoacetate, D(-)-3-hydroxybutyrate and acetone) are generated mainly in the liver via the 3-hydroxy-3-methylglutaryl-CoA pathway, carried to and utilized in extrahepatic tissues as an energy source during starvation and diabetes in particular due to their overproduction as the consequence of elevated fatty acid oxidation and lowered glucose metabolism. (omitted)

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2679-2682
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• 2012

A simple one-pot synthesis of two derivatives of 1,4-dihydropyridines has been described under reflux conditions using copper iodide nanoparticles (CuI NPs) as a catalyst in high yields. This method demonstrated four-component coupling reactions of aldehydes and ammonium acetate via two pathways. In one route, the reaction was performed using 2 eq ethyl acetoacetate while in the other one 1 eq ethyl acetoacetate and 1 eq malononitrile were used. The CuI NPs was reused and recycled without any loss of activity and product yield. It is noteworthy to state that wide range of the 1,4-dihydropyridines have attracted large interest due to pharmacological and biological activities.

• Biomedical Science Letters
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• v.21 no.4
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• pp.241-247
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• 2015

Lactate and ketone bodies are considered biological markers for ketosis and several inherited metabolic disorders. In the current study, the specific ratios of lactate and ketone bodies as analytical tools for differential diagnosis of various lactic acidosis were devised. The study included a protein precipitation step following tert-butyldimethylsilyl derivatisation. Total run time was approximately 30 min including sample preparation and GS/MS analysis. The limits of detection were below 0.1 pg/mL over the targeted 4 analytes. The calibration curve was linear over the concentration range of $0.001{\sim}250{\mu}g/mL$ for pyruvate, beta-hydroxybutyrate, and acetoacetate ($R^2$ > 0.99). Inter-day accuracy and precision were 87.7~94.8% with RSD of 2.5~5.7% at 2 levels. Absolute recoveries (%) of target analytes were 87.0~98.4%. The method was validated for the quantification of lactate and ketone bodies for differentiation of lactic acidosis.

• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.291-295
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• 2006

The keto-enol tautomeric equilibrium constant, K, of ethyl acetoacetate in compressed and supercritical carbon dioxide was determined by using FT-IR (Fourier transform infrared) spectroscopy at three different temperatures. In order to investigate the effect of solvent density, the $CO_{2}$ pressure was systematically changed at a constant temperature. As the $CO_{2}$ density is increased, the amount of keto tautomer is increased, causing the K value to decrease. The modified lattice fluid hydrogen bonding theory has been applied to investigate the effect of density on the K.

• Bulletin of the Korean Chemical Society
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• v.6 no.4
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• pp.249-251
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• 1985

• Environmental Analysis Health and Toxicology
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• v.25 no.4
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• pp.295-306
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• 2010

Objectives : This study was undertaken to examine the metabolomic changes due to gender and diurnal variation at sampling time and to identify an appropriate time point for urine sampling in epidemiologic studies using metabolomic profiles. Methods : Urine samples were collected twice a day (morning and afternoon) from 20 healthy Korean adults after fasting for 8 hours. The metabolomic assay was investigated using $^1H$ NMR spectroscopy coupled with the principal components analysis (PCA) and partial least squares discriminant analysis (PLS-DA). The metabolites responsible for differentiation between groups were identified through the loading plot of PLS-DA and quantified using Chenomx NMR Suite with a 600 MHz library. Results : Metabolites responsible for differentiation in gender and sampling time were creatinine, trimethyl anine oxide (TMAO), hippurate, mannitol, citrate and acetoacetate. Dimethylamine showed difference only as a factor of diurnal time. The level of creatinine was higher in men compared to women, and the levels of citrate, TMAO, hippurate, mannitol, and acetoacetate were higher in women compared to men. The levels of creatinine, TMAO, hippurate, dimethylamine and mannitol were higher in the morning rather than the afternoon while those of citrate and acetoacetate were higher in the afternoon rather than the morning. Conclusions : Since urinary metabolomic profiles varied by gender and diurnal cycle, urine sampling should be performed at the same time point for all participants in epidemiologic studies using metabolomic profiles.

• Archives of Pharmacal Research
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• v.23 no.5
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• pp.446-449
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• 2000

Imidazonaphthothiazole derivatives 3∼6 were prepared by treatment of 2-aminonaphtho[2,3-d]-thiazole-4,9-dione(1) with phenacyl bromide, chloroacetic acid, diethyl oxalate and 2,3-dichloroquinoxaline respectively. The reaction of 1 with ethyl acrylate, ethyl acetoacetate and diethyl malonate gave the corresponding naphthothiazolopyrimidine derivatives 8∼11.

• Archives of Pharmacal Research
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• v.20 no.5
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• pp.507-509
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• 1997

Several new spiro compounds were synthesized via one-pot ternary condensation of isatin, malononitrile and each of thiobarbituric acid, barbituric, 3-methyl-pyrazolin-5-one, 1-phenyl-3-methyl-pyrazolin-5-one, acetylacetone, benzoylacetone, ethyl acetoacetate, phenacyl cyanide or ethyl-cyanoacetate dimer. Structures and reaction mechanisms were reported and supported via a second synthetic route.

• Bulletin of the Korean Chemical Society
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• v.23 no.5
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• pp.736-740
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• 2002

An efficient and practical synthetic method of △1 -3-octalone, which is a versatile building block for thesyntheses of polycyclic compounds, has been developed. The dianion of ethyl acetoacetate reacts with cyclohexene-1-carboxaldehyde (3) to produce the aldol adduct 6, which then undergoes Mn(Ⅲ)-mediated radical cyclization followed by acetate elimination to give △1 -3-octalone 4. A detailed mechanistic insight of Mn(Ⅲ)-mediated cyclization of 6 has been disclosed.