• Bulletin of the Korean Chemical Society
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• 제32권10호
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• pp.3720-3725
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• 2011

$TiO_2$ nanoparticles were synthesized and characterized by SEM and XRD techniques. The $TiO_2$ nanoparticles were employed as a recyclable, inexpensive and efficient catalyst for the synthesis of substituted quinoxalines in high to excellent yields and in relatively short duration.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2245-2250
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• 2014

A new accepter unit, 6,7-difluoro-2,3-dihexylquinoxaline, was prepared and utilized for the synthesis of the conjugated polymers containing electron donor-acceptor pair for OPVs. New series of copolymers with dioctyloxybenzodithiophene as the electron rich unit and 6,7-difluoro-2,3-dihexylquinoxaline as the electron deficient unit are synthesized. The solid films of poly[2,6-(4,8-bis(2-ethylhexyloxy)benzo[1,2-b:4,5-b']dithiophene)-alt-5,8-(6,7-difluoro-2,3-dihexylquinoxaline)] (PBQxF) and poly[2,6-(4,8-bis(2-ethylhexyloxy) benzo[1,2-b:4,5-b']dithiophene)-alt-5,8-(6,7-difluoro-2,3-dihexyl-5,8-di(thiophen-2-yl) quinoxaline)] (PBDTQxF) show absorption bands with maximum peaks at about 599 and 551 nm and the absorption onsets at 692 and 713 nm, corresponding to band gaps of 1.79 and 1.74 eV, respectively. The devices comprising PBQxF with $PC_{71}BM$ (1:2) showed open-circuit voltage ($V_{OC}$) of 0.64 V, short-circuit current density ($J_{SC}$) of $1.58mA/cm^2$, and fill factor (FF) of 0.39, giving power conversion efficiency (PCE) of 0.39%. To obtain absorption in the longer wavelength region, thiophene units without any alkyl group are incorporated as one of the monomers in PBDTQxF, which may result in low solubility of the polymers to lead lower efficiency.

• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3304-3308
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• 2010

Condensation of 4-amino-5-mercapto-3-($\alpha$-naphthyl)-s-triazole (1) with cyanogen bromide gives 6-amino-3-($\alpha$-naphthyl)-s-triazolo[3,4-b]-1,3,4-thiadiazole (2) which on condensation with chloranil yields 3,9-di-($\alpha$-naphthyl)-6,14-dioxo-bis-(s-triazolo[3,4-b]-1,3,4-thiadiazolo[3,2-b]imidazo[4,5-b]cyclohexane]-5a,6a-diene) (3). 3-($\alpha$-naphthyl)-s-triazolo[3,4-b]-1,3,4-thiadiazolo[3,2-b]imidazo[4,5-b]quinoxaline (4) is obtained by a similar condensation of (2) with 2,3-dichloroquinoxaline. The reaction of (2) with $\alpha$-haloketones followed by bromination affords 7-aryl-3-($\alpha$-naphthyl)-imidazo[2,1-b]-1,3,4-thiadiazolo[2,3-c]-s-triazoles (5) and their 6-bromo analogues 6 respectively. The structures of all newly synthesized compounds were established on the basis of elemental analyses, IR, $^1H$-NMR. The antibacterial and antifungal activities of all newly synthesized compounds have also been evaluated.

• 한국식품과학회지
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• 제8권2호
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• pp.85-89
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• 1976

Gas chromatography를 이용하여 methylglyoxal, diacetyl 및 triose reductone과 같은 dicarbonyl류(類)를 분리측정(分離測定)할 수 있는 조건(條件)을 실험(實驗)하였던 바 다음과 같은 결과(結果)를 얻었다. 1. MG, DAc, DTR의 혼합물(混合物)에 OPD를 반응시켜 quinoxaline 유도체(誘導體)를 만들고 이것을 클로로포름으로 추출(抽出)하면 MG 및 DAc는 거의 100%추출(抽出)되었고, DTR은 에틸에테르에 추출(抽出)되었다. 2. SE-30을 충진제로하여 얻어진 column 조건(條件)에서 MG-OPD와 DAc-OPD는 완전히 분리측정(分離測定)할 수 있었다. 3. 당류중(糖類中) glucose의 OPD 축합물형성조건(縮合物形成條件)은 D-glucose 180mg을 0.1N-NaOH 용액 10ml에서 5분간(分間) 가열후 OPD와 반응(反應)시켜 pH 6. 0에서 클로로포름으로 추출(抽出)하여 GLC에 겉면 5개의 peak가 나타났고, 그 중에서 2개는MG-OPD와 DAo-OPD임을 확인하였다. 그러나 중성(中性) 및 산성가열(酸性加熱)인 경우는 peak가 확실치 않았다.

• Archives of Pharmacal Research
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• 제27권11호
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• pp.1093-1098
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• 2004

In this study, certain 3-methyl-2-[4-(substituted amino carbonyl)anilino] quinoxalines, (2a-d) and (3a-d), were synthesized from the new key compound 2-[4-(ethoxycarbonyl)anilino]-3-methyl quinoxaline (1). In addition, a series of 2-[4-(arylidene hydrazinocarbonyl)anilino]-3-methyl quinoxalines (5a-e), as well as their cyclized oxadiazolinyl derivatives (6a-e), and a series of 2-[4-$N^2$-acylhydrazinocarbonyl)anilino]-3-methyl quinoxalines (7a-d), as well as their cyclized oxadiazolyl derivatives (8a-d) were also prepared. Some of these derivatives were evaluated for antimicrobial activity in vitro. It was found that all the selected compounds exhibit antimicrobial activity and that compound 5b had a broad spectrum of activity.

• 한국물환경학회지
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• 제28권6호
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• pp.902-910
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• 2012

The photodegradation characteristics of 30 pharmaceuticals were investigated by batch experiments using Ultraviolet (UV) reactor. The investigated pharmaceuticals include antibiotics, analgesics and antiarrhythmic agents etc. Tested water was prepared by simultaneously spiking 30 pharmaceuticals into pure water, and each experiment was conducted using 3 types of UV lamps. As a result, batch experiments showed that reactions of all the investigated pharmaceuticals followed pseudo-first order reaction regardless of the applied UV lamps. Among the pharmaceuticals, Cyclophosphamide, 2-Quinoxaline carboxylic acid and Clarithromycin proved to be the most UV-resistant compounds. Contrarily, Ceftiofur, Diclofenac and Ketoprofen were easily degraded by all the UV lamps. Dissolved organic carbon (DOC) concentration hardly changed although the concentration of the pharmaceuticals concentration gradually decreased with time, indicating that the degradation of parent pharmaceuticals may produce their intermediates during UV treatment.

• Archives of Pharmacal Research
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• 제26권2호
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• pp.107-113
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• 2003

Several fused triazolo and ditriazoloquinoxaline derivatives such as 1-aryl-4-chloro-[1,2,4]triazolo[4,3-a]quinoxalines (3a-d), 4-alkoxy[1,2,4]triazolo[4,3-a]quinoxalines (4a,b), 4-substituted-amino-[1,2,4] triazolo[4,3-a]quinoxalines (5a-h), 1-(aryl)-[1,2,4]triazolo[4,3-a]quinoxalin-4(5H)-thione (6), 4-(arylidenehydrazino )-1-phenyl-[1,2,4]triazolo[4,3-a]quinoxalines (10a-e) and [1,2,4]ditriazolo[4,3-a:3',4'-c]quinoxaline derivatives (11-13) have been synthesized and some of these derivatives were evaluated for antimicrobial and antifungal activity in vitro. It was found that compounds 3a and 9b possess potent antibacterial activity compared to the standard tetracycline.

• Bulletin of the Korean Chemical Society
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• 제23권4호
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• pp.567-570
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• 2002

Diazotization of 3-amino-2-ethoxycarbonylthieno[2,3-b]quinoxaline 1 gave the diazonium salt 2 which was reacted with SO2 and N-methylaniline to give sulfamoylquinoxaline derivatives 3-5. Imidazothienoquinoxaline 8 was obtained from the reaction of carboxylic acid hydrazide 6 with nitrous acid and followed by boilling the carboazide 7 in dry xylene. Also, compound 6 react with CH(OEt)3 to give aminopyrimidine 9 which was reacted with arylidene malonodinitrile, furfural and/or dimethoxy-tetrahydrofuran to afford compounds 10, 11 and/or 12 respectively. Refluxing of 6 with CS2 gave oxadiazolylthienoquinoxaline 13, reaction of 13 with hyrazine hydrate, CH(OEt)3, nitrous acid, CS2 and a-halocompounds to give 14-19.

• Bulletin of the Korean Chemical Society
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• 제32권3호
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• pp.1007-1010
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• 2011

$Ir(dpq/dpqx)_2$(przl-R) complexes were prepared and their electrochemical properties were investigated, where dpq, dpqx and przl-R represent 2,3-diphenylquinoline, 2,3-diphenylquinoxaline and N-phenyl-R-pyrazolonate derivatives, respectively. The iridium complexes containing dpq and dpqx as main ligands were reported to show red phosphorescence, and involvement of a pyrazolonate ancillary ligand in the iridium complexes led to high luminous efficiency for organic light-emitting diodes. In this study, we synthesized red phosphorescent iridium complexes containing a new pyrazolonate ancillary ligand and investigated the HOMOs, LUMOs and resulting electrochemical gaps of $Ir(dpq/dpqx)_2$(przl-R) by cyclic voltammetry. The emission wavelengths of the complexes at 600 - 640 nm were consistent with the gaps of 1.95 - 2.03 eV measured from reduction and oxidation potentials of the complexes.

• Elastomers and Composites
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• 제50권3호
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• pp.175-183
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• 2015

A series of fluorinated aromatic poly(hydroxyamide)s (PHAs) were synthesized by direct polycondensation of diacides containing 2,6-dimethylphenoxy group and quinoxaline ring in the main chain with 2,2-bis-(3-amino-4-hydroxyphenyl) hexafluoropropane. The PHAs had relatively low inherent viscosities in the range of 0.35~0.43 dL/g at $35^{\circ}C$ in DMAc solution. All PHAs exhibited excellent solubility in aprotic solvents such as NMP, DMAc, DMF and DMSO as well as in common organic solvents such as pyridine, THF, and m-cresol at room temperature. However, the poly(benzoxazole)s (PBOs) were quite insoluble in all organic solvents except partially soluble in concentrated sulfuric acid. The PBOs showed glass transition temperatures between 233 and $284^{\circ}C$ by DSC and maximum weight loss temperatures in the range of $536-546^{\circ}C$ by TGA.