• YAKHAK HOEJI
• /
• v.39 no.2
• /
• pp.118-130
• /
• 1995

Aliphatic & aromatic compounds with two nucleophilic functional groups which were chosen as nucleophiles reacted with 2,3-dichloro-1,4-naphthoquinone as a substrate to give cyclized products by nucleophilic vinyl substitution. And the trends in the syntheses of the heterocyclic compounds was studied and expounded. Besides, the biological activities of the products, especially activity as an agricultural chemical, were examined. Moreover 5-aminomethyl-2-pyrrolidinone was synthesized for the purpose of forming a polynuclear heterocyclic compound containing a similar structure of azasteroid. However only one chlorine of 2,3-dichloro-1,4-naphthoquinone was replaced by an amino group of pyrrolidinone and cyclization did not take place.

• Archives of Pharmacal Research
• /
• v.17 no.6
• /
• pp.411-414
• /
• 1994

Phenylazocyanothioacetamide 1 reacts with malononitrile to afford the pyridinethione 4 which reacts with phenacylbromide to yield the pyridine-S-phenacyl derivative 6, 1 reacts with ethyl cyanoacetate to yield the pyridazine derivative, 8, and with phenacyl bromide to afford the N-phenacyl derivative 11, instead of the thiazole 10. Compound 11 afforded the pyrazolopyridine 13 on reaction with malononitrile while 10 was obtained on coupling of the thiazole 14 with diazotised aniline. Compound 10 reacts with malononitrile to afford the thizaolyl pyridazine 15. Compound 1 reacts with malononitrile dimer to afford the pyriodopyridazine derivative 17a. 1 reacts also with active methylene heterocycies to afford the pyrazolo and thiazolo-fused phridazines 20 and 23 respectively.

• Applied Chemistry for Engineering
• /
• v.25 no.2
• /
• pp.142-146
• /
• 2014

The separation of nitrogen heterocyclic compound (NHC) contained in a model coal tar fraction of nine components system was investigated by distribution equilibrium. The model coal tar fraction comprising NHC group (NHCs; indole (In), quinoline (Q), iso-quinoline (iQ), quinaldine(Qu)), bicyclic aromatic compound group (BACs; 1-methylnaphthalene (1MN), 2-methylnaphthalene (2MN), dimethylnaphthalene (DMN)), biphenyl (Bp) and phenyl ether (Pe) and the aqueous methanol were used as the raw materials and the solvent of this work, respectively. A batch-stirred tank was used as the liquid-liquid contact unit of this work. The distribution coefficient of NHCs increased by increasing the equilibrium operation temperature, whereas the selectivity of NHCs with respect to BACs decreased. Decreasing the initial volume ratio of water to the solvent resulted in deteriorating the selectivity of NHCs in reference to BACs, but improving the distribution coefficients of NHCs. At a fixed experimental condition, the sequence of the distribution coefficient and the selectivity with reference to BACs for each groups was increased in order of NHCs > Bp > BACs > Pe and NHCs > Bp> Pe, respectively. Also, the sequence of the distribution coefficient for entire compounds was in order of In > iQ = Q > Qu > Bp > 1MN = 2MN > Pe > DMN. The maximum yield of NHCs and the selectivity of NHCs based on BACs obtained by methanol extraction were 94 and 23%, respectively. Furthermore, the recovery process for NHCs from coal tar was studied by using the experimental results from this work.

• Proceedings of the Korean Fiber Society Conference
• /
• 2001.10a
• /
• pp.247-250
• /
• 2001

2, 3-Dicyanopyrazine derivatives have been synthesized by condensation of diaminomaleonitrile(DAMN) and a -diketone compounds. Diaminomaleohitrile (DAMN) is well known as a tetramer of hydrogen cyanide and a useful compound in the chemical industry not on]y as a starting material for synthesis of various heterocyclic compounds but also as an intermediate for synthesis of glycine, adenine, guanine et al. (omitted)

• Bulletin of the Korean Chemical Society
• /
• v.14 no.1
• /
• pp.32-38
• /
• 1993

3-(3-Bromotetrahydrofuran-2-yl)-3-cephem 7 was obtained from 3-(2-hydroxyethyl)vinyl-3-cephem 6 by the cyclization reaction using N-bromosuccinimide. Compound 5 was prepared by Wittig reaction, namely a coupling of cephem-derived triphenylphosphonium salt 3 with aldehyde component 4 in the presence of base.

• Proceedings of the PSK Conference
• /
• 2003.10b
• /
• pp.182.1-182.1
• /
• 2003

Flavonoids with oxygen atoms are known to have potent biological effect.They have been studied long as major antioxidants which protect cell membranes. Recent medical surveys show that increased intake of selenium decreases the risk of breast, colon, lung and prostrate cancer by preventing free radical generation. The flavonoids, isoflavonoids, and coumarins which form the bulk of these compounds are very polar and have limited use as drugs which have to pass through BBB(Brain Blood Barrier)The non-polar property is increased by exchange oxygen to selenium as a part of heterocyclic compound. (omitted)

• Bulletin of the Korean Chemical Society
• /
• v.18 no.3
• /
• pp.305-310
• /
• 1997

The synthesis and characterization of the platinum heterocyclic carboxaldehyde thiosemicarbazone complexes [NC5H4CRNNC(S)NHR'PtCl] (R=H, R'=CH3(1); R=CH3, R'=CH3(2); R=CH3, R=H(3)) and diphenylphosphinophenyl carboxaldehyde thiosemicarbazone complexes [Ph2PC6H4CHNNC(S)NHRPtCl] (R=CH3(5); R=iC3H7(6); R=Ph(7)) are described. Compounds 1-3 were prepared by reaction of Pt(SEt2)2Cl2 with 2-acetylpyridine-4-alkylthiosemicarbazone in the presence of NEt3. Compounds 5-7 were prepared using Pt(SEt2)2Cl2 in toluene with diphenylphosphinophenyl carboxaldehyde alkylthiosemicarbazone. The compounds have been characterized by microanalysis, NMR (1H, 13C, 31P) spectroscopy, and single-crystal X-ray diffraction. X-ray single crystal diffraction analysis reveals that compound 5 is a mononuclear platinum compound with P,N,S-coordination mode.

• Analytical Science and Technology
• /
• v.6 no.3
• /
• pp.307-311
• /
• 1993

Ionophore, which contains 5-membered heterocyclic compound, was prepared. $Mg^{2+}$ was determined by salting-out technique using ionophore as a chelating reagent. After $Mg^{2+}$ was extracted into the acetonitrile layer as a Mg-$(Ionophore)_2$ complex from acetate buffered aqueous solution by salting-out extraction technique, absorbance of complex was recorded by atomic absorption spectrophotometry. Optimum pH was between 2.5 and 5.0 for extraction and 1:2([$Mg^{2+}$]/[ionophore]) complex were formed. The range of detection was 0.24ppm~2.4ppm and $Ca^{2+}$ and EDTA were interfered in the determination of $Mg^{2+}$.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.11
• /
• pp.6039-6046
• /
• 2013

Cr(VI)-heterocyclic complex[Cr(VI)-2-methylpyrazine] was synthesized by the reaction between of heterocyclic compound(2-methylpyrazine) and chromium trioxide, and characterized by IR and ICP analysis. The oxidation of benzyl alcohol using Cr(VI)-2-methylpyrazine in various solvents showed that the reactivity increased with the increase of the dielectric constant(${\varepsilon}$), in the order : cyclohexene${\rho}$) was Cr(VI)-2-methylpyrazine= -0.65(308K). The observed experimental data have been ratiolized. The hydride ion transfer causes the prior formation of a chromate ester in the rate-determining step.

• Analytical Science and Technology
• /
• v.10 no.6
• /
• pp.408-417
• /
• 1997

Normal phase or reversed phase liquid chromatographic separation of some structural isomers of functionalized heterocyclic compounds has been carried out by using several different columns and various mobile phases. The optimal experimental conditions for separation of structural isomers were found on a ternary solvent system including alcohol as a modifier. This polar modifier is preferentially adsorbed onto strong adsorption site, leaving a more uniform population of weaker site that then serve to retain the sample. This 'deactivation' of the adsorbent leads to a number of improvements in subsequent separations. The optimal mobile phase system of separation were found on normal phase on structural isomers. Retention mechanism of normal phase system was also studied depending on adsorption strength between solute and stationary phase of column. However, retention factors of reversed phase system were found on hydrophobic interaction with solvophobic effect.