• 대한화학회지
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• 제51권2호
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• pp.115-124
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• 2007

α, β-불포화 케톤 유도체를 실리카-황산 촉매 하에서 비용매 교차 알돌 응축 반응법을 이용하여 합성하였다. 합성 수율은 90% 이상이었으며, 사용된 촉매는 회수 가능하였다. 합성돤 화합물들의 물리화학적인 특성은 IR, NMR, Mass 등의 분광학적 분석 방법을 이용하여 결정하였다. 케톤 생성물에 미치는 치환기 효과는 측정된 분광 데이터와 Hammet 치환기 상수간의 상관관계로 표현되는 다중 상관계수 방정식에 의하여 잘 설명될 수 있었다.

• 대한화학회지
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• 제47권4호
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• pp.345-353
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• 2003

6-Chloro-3-methoxycarbonylmethylene-2-oxo-1,2,3,4-tetrahydroquinoxaline(5) 또는 3-methoxycarbonylmethylene- 6-nitro-2-oxo-1,2,3,4-tetrahydroquinoxaline(6)을 hydrazine hydrate와 반응시켜 3-hydrazinocarbonylmethylene-2-oxo-1,2,3,4-tetrahydroquinoxaline류(7, 8)를 합성하였다. 화합물 7 또는 8을 치환 벤즈알데히드류 및 헤테로고리 알데히드류와 반응시켜 quinoxaline류(9-14)를 각각 합성하였다. 합성한 화합물들은 dimethyl sulfoxide 용액에서 enamine형, methylene imine형 또는 enamine형, methylene imine형, enaminol형 사이에 토토머화 현상을 나타내었는데, 이들의 토토머 비를 1H NMR로서 측정하였다.

• 대한화학회지
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• 제47권3호
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• pp.241-249
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• 2003

3-(1-Ethoxycarbonyl)ethyl-1,2-dihydro-2-oxoquinoxaline(8)을 hydrazine hydrate와 반응시켜 3-(1-hydrazinocarbonyl)ethyl-2-hydroxyquinoxaline(9)을 합성하였고, 화합물 9를 치환 벤즈알데하이드류 또는 heteroaryl aldehyde류와 반응시켜 2-hydroxyquinoxaline류(10-12)를 합성하였다. 또한 화합물 9를 alkyl (ethoxymethylene)- cyanoacetate류 또는 ethoxymethylenemalononitrile과 반응시켜 분자내 고리화반응에 의하여 5-amino-1-[2-(3-hydroxyquinoxalin-2-yl)propanoyl]-pyrazole류(13)를 합성하였다. 얻어진 화합물 10-13은 dimethyl sulfoxide 용액에서 lactam형과 lactime형 사이에 토토머화 현상을 나타내었는데, 이들의 토토머 비를 $^1H$ NMR로서 측정하였다. 그리고 합성한 화합물들에 대한 제초력과 살균력도 조사하였다.

• 대한화학회지
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• 제44권5호
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• pp.435-440
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• 2000

2-Methoxycarbonylmethylene-1,2-dihydro-4H-pyrido[2,3-b]pyrazin-3-one(5)을 hydrazine hydrate와 ethylenediamine을 반응시켜 2-hydrazinocarbonylmethylene-1,2-dihydro-4H-pyrido[2,3-b]pyrazin-3-one(6)과 2-aminoethylcarbamoylmethylene-1,2-dihydro-4H-pyrido[2,3-b]pyrazin-3-one(7)을 각각 합성하였다. 화합물 6 또는 7을 치환 벤즈알데히드류 및 헤테로아릴 알데히드류와 반응시켜 pyrido[2,3-b]pyrazin류(8-13)를 각각 합성하였다. 몇가지 pyrido[2,3-b]pyrazin은 용액에서 enamine형,methylene imine형, methylene imine형,enaminol형 사이에 토토머화 현상을 나타내었는데, 이들의 토토머 비는 1H NMR로서 측정하였다.

• 대한화학회지
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• 제42권4호
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• pp.449-453
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• 1998

6-Chloro-2-hydrazinoquinoxaline 4-oxide(11)와 ethyl chloroglyoxylate를 반응시켜 분자내 고리화반응에 의한 ethyl 8-chloro-4H-1,3,4-oxadiazino[5,6-b]quinoxaline-2-carboxylate(12)를 합성하였다. 화합물 12를 hydrazine hydrate와 반응시켜 $C_2$-hydrazinocarbonyl 유도체 13이 합성되었는데, 이것을 치환 벤즈알데히드류 및 헤테로아릴 알데히드류와 반응시켜 8-chloro-2-(substituted benzylidenehydrazinocarbonyl)-4H-1,3,4-oxadiazino[5,6-b]quinoxaline류(14) 및 8-chloro-2-[(2-substituted methylidene)hydrazinocarbonyl]-4H-1,3,4-oxadiazino[5,6-b]quinoxaline류(15)를 각각 합성하였다.

• Mycobiology
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• 제37권2호
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• pp.141-146
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• 2009

Novel copper(II) complexes have been synthesized from the macrocyclic Schiff bases derived from Knoevenagel condensed ${\beta}$-ketoanilides (obtained by the condensation of acetoacetanilide and substituted benzaldehydes), 4-aminoantipyrine and ophenylene diamine. The structural features have been determined from their analytical and spectral data. All the Cu(II) complexes exhibit square planar geometry. Their high molar conductance values support their 1 : 2 electrolytic nature. The magnetic moment data provide evidence for the monomeric nature of the complexes. The X-band ESR spectra of the |$CuL^1$|$(OAc)_2$ in DMSO solution at 300 and 77 K were recorded and their salient features are reported. The in vitro biological screening effects of the investigated compounds were tested against the bacterial species Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris and Pseudomonas aeruginosa and fungal species Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans by well diffusion method. A comparative study of inhibition values of the Schiff bases and their complexes indicate that complexes exhibit higher antimicrobial activity than the Schiff bases. Copper ions proved to be essential for the growth-inhibitor effect. The extent of inhibition appeared to be strongly dependent on the initial cell density and on the growth medium.

• 한국응용과학기술학회지
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• 제7권1호
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• pp.13-24
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• 1990

2-N,N,N-trimethyl ammonia decanoate, 2-N,N,N-trimethyl ammonio dodecanoate, 2-N,N,N-trimethyl ammonia tetradecanoate and 2-N,N,N-hexadecanoate with in straight long chain alkyl carboxybetaines, and N-decyl N,N-dimethyl ammonio ethanoate, N-dodecyl N,N-dimethyl ammonia ethanoate, N-tetradecyl N,N-dimethyl ammonia ethanoate and N-hexadecyl N,N-dimethyl ammonia ethanoate with in nitrogen-straight long chain alkyl carboxy betaines measured respectively surface tensions by the stalagmometer method at various temperature, also their critical micelle concentration were evaluated. In micellization, the contribution of standard free energy change(${\Delta}G^{\circ}m$), standard enthalpy change(${\Delta}H^{\circ}m$) and standard entropy change (${\Delta}S^{\circ}m$), have been calculated, with increasing temperature. ${\Delta}H^{\circ}m$ changes from negative, and a similar change in the sign of ${\Delta}H^{\circ}m$ is observed with increasing chain length at $25^{\circ}C$, while the entropy of micellization, ${\Delta}S^{\circ}m$ is positive over the temperature range studied, it becomes less so at higher temperatures. Estimates of the enthalpy and entropy contribution attributable to the ion head group and alkyl chain have been made. The enthalpy and entropy change, per methylene group increase respectively with increasing chain length the result are discussed in terms of current theories of micellization.

• Archives of Pharmacal Research
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• 제28권5호
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• pp.518-528
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• 2005

In the present study, the antioxidative and inhibitory activity of Zingiber officinale Rosc. Rhizomes-derived materials (on mushroom tyrosinase) were evaluated. The bioactive co mponents of Z. officinale rhizomes were characterized by spectroscopic analysis as zingerone and dehydrozingerone, which exhibited potent antioxidant and tyrosinase inhibition activities. A series of substituted dehydrozingerones [(E)-4-phenyl-3-buten-2-ones] were prepared in admirable yields by the reaction of appropriate benzaldehydes with acetone and the products were evaluated in terms of variation in the dehydrozingerone structure. The synthetic analogues were examined for their antioxidant and antityrosinase activities to probe the most potent analogue. Compound 26 inhibited Fe$^{2+}$-induced lipid peroxidation in rat brain homogenate with an IC$_{50}$ = 6.3${\pm}$0.4 ${\mu}$M. In the 1,1-diphenyl- 2-picrylhydrazyl (DPPH) radical quencher assay, compounds 2, 7, 17, 26, 28, and 29 showed radical scavenging activity equal to or higher than those of the standard antioxidants, like ${\alpha}$-tocopherol and ascorbic acid. Compound 27 displayed superior inhibition of tyrosinase activity relative to other examined analogues. Compounds 2, 17, and 26 exhibited non-competitive inhibition against oxidation of 3,4- dihydroxyphenylalanine (L-DOPA). From the present study, it was observed that both number and position of hydroxyl groups on aromatic ring and a double bond between C-3 and C-4 played a critical role in exerting the antioxidant and antityrosinase activity.

• 대한화학회지
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• 제48권1호
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• pp.28-32
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• 2004

초임계 이산화탄소 용매에서의 (벤질렌)삼페닐 인 일리드 화합물의 카르보닐 화합물과의 Wittig 반응을 연구하였다. 소량의 조용매 (THF, 5%)를 첨가한 이산화탄소 (24 mL 용기)에 녹인 (벤질렌)삼페닐 인 일리드 (약 1 mmol)를 여러 방향족 알데히드와 초임계 조건(80 $^{\circ}C$, 2,000 psi) 에서 2시간 반응시켜 올레핀 화합물을 좋은 수율로 얻을 수 있었다. 새로운 조건에서의 반응은 기존 용매 (THF)에서의 반응보다는 약간 느리게 나타났으나 생성물의 (E)- 와 (Z)-이성체 비율에 차이가 있었다. 두 이성체가 함께 생성되는 반응의 경우 (Z)-이성체의 비율이 증가하였다. 반면 t-butylcyclohexanone과 같은 케톤과의 반응은 두 조건에서 모두 낮은 전환을 보였다. 이 연구를 통하여 이산화탄소에서의 Wittig 반응이 초임계 조건에서 좋은 수율로 이루어지며 이 새로운 용매의 사용으로 반응선택성의 변화가 가능할 수 있다는 초기 결과를 얻었다. 이 결과는 Wittig 반응과 같은 유용한 유기반응을 친환경 용매 (이산화탄소)에서 수행할 수 있도록 전환하는데 좋은 자료가 될 수 있다고 본다.