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β-Difluoro-α-trimethylsilyl-γ-lactam 유도체의 합성
채규윤,곽경철,문재정,최장호 圓光大學校 基礎自然科學硏究所 2000 基礎科學硏究誌 Vol.18 No.1
α-위치만 선택적으로 difluoromethylene기가 도입된 α.α-difluoro-γ-trimethylsilyl-γ-lactam 유도체(6)들은 ethyl α.α-difluoro-γ-trimethylsilyl-γ-iodopentanoate(4)는 일차아민 유도체와의 반응으로부터 비교적 편리한 작용조건과 비교적 좋은 수득률로 합성하였다. The target of α.α-difluoro-γ-trimethylsilyl-γ-lactam derivatives(6) with selectively in corporated difluoromethylene on α-position were readily prepared form reaction ethyl α.α-difluoro-γ-trimethylsilyl-γ-iodopentanoate(4) and primary derivatives in moderate yields.
Addition of α,α-Difluoroiodomethyl Ketones to Alkenes with a Copper Catalyst
Kwak, Kyung-Chell,Lee, Woo-Yiel,Zheshan, Quan,Lee, Young-Hang,Yun, Young-Gab,Kwak, Gyu-Beum,Chung, Hun-Taeg,Kwon, Tae-Oh,Chai, Kyu-Yun Korean Chemical Society 2005 Bulletin of the Korean Chemical Society Vol.26 No.1
The addition reactions of $\alpha$,$\alpha$-difluoroiodomethyl n-butyl ketone, α,α-difluoroiodomethyl cyclohexyl ketone, or $\alpha$,$\alpha$-difluoroiodomethyl phenyl ketone to alkenes were successfully accomplished in good yields in the presence of copper powder. The reaction was also applicable to alkenes containing a variety of functional groups such as ester, trimethylsilyl, or ether group. Acetonitrile was determined to be the best solvent in the present study and the reaction was performed at 55 ${^{\circ}C}$ for 15-22 h. This reaction provides a new, efficient and general method for the synthesis of $\alpha$,$\alpha$-difluoro functionalized ketones.
Addition of α,α-Difluoroiodomethyl Ketones to Alkenes with a Copper Catalyst
Kyung Chell Kwak,Woo-Yiel Lee,Quan Zheshan,Young Hang Lee,Young-Gab Yun,Gyu Beum Kwak,Hun-Taeg Chung,Tae-Oh Kwon,Kyu Yun Chai* 대한화학회 2005 Bulletin of the Korean Chemical Society Vol.26 No.1
The addition reactions of α,α-difluoroiodomethyl n-butyl ketone, α,α-difluoroiodomethyl cyclohexyl ketone,or α,α-difluoroiodomethyl phenyl ketone to alkenes were successfully accomplished in good yields in the presence of copper powder. The reaction was also applicable to alkenes containing a variety of functional groups such as ester, trimethylsilyl, or ether group. Acetonitrile was determined to be the best solvent in the present study and the reaction was performed at 55 oC for 15-22 h. This reaction provides a new, efficient and general method for the synthesis of α,α-difluoro functionalized ketones.
β-Fluoro-α-phenylpyrrole 유도체의 합성에 관한 연구
郭炅喆,吳賢哲,鄭悳商,李英行,白承和,金鍾洙,蔡奎允 濟州大學校 基礎科學硏究所 2001 基礎科學硏究 Vol.14 No.2
플루오르가 선택적으로 치환된 유기화합물은 모체 화합물 보다 향상된 생리활성을 지니는 경우가 많이 보고 된바 있다. 이는 할로젠족 원소인 플루오르의 큰 전기음성도 때문에 비교적 강한 탄소플루오르 결합 형성 및 증가된 리피드 용해도 때문이다. Pyrrole과 그의 유도체들은 폴리머, 의약품 그리고 염료 등에 광범위하게 사용되어 왔고 오래 전부터 잘 알려진 화합물이다. 최근 자연계에서 산출되거나 합성 가능한 플루오르가 선택적으로 치환된 fluoropyrrole 유도체들은 진통제, 소염제 및 살균제 등으로 다양하게 이용될 수 있음이 알려져 있기 때문에 fluoropyrrole 유도체의 합성에 대한 연구가 활발히 진행되고 있다. 일반적으로 플루오르는 반응성이 매우 커서 유기화합물에 대한 선택적인 플루오르기의 도입이 극히 제한적이다.
Synthesis of 6-Alkyloxyl-3,4-dihydro-2(1H)-quinoliones and Their Anticonvulsant Activities
Kyu-Yun Chai,Jun-Min Wang,노정래,Kyung-Chell Kwak,Hee-Cheol Kang,Chang-Soo Jun,Zhe-Shan Quan 대한화학회 2005 Bulletin of the Korean Chemical Society Vol.26 No.11
A series of 6-alkyloxyl-3,4-dihydro-2(1H)-quinoliones (5a-5n) were synthesized through nitration, reduction, diazotization, hydrolysis and alkylation from 3,4-dihydro-2(1H)-quinolione. Their structures were characterized by IR, 1H-NMR and MS. The anticonvulsant activity was evaluated by the Maximal electroshock test (MES) and the subcutaneous pentylenetetrazole (Metrazole) test (sc-Met). The neurotoxicity was measured by the Rotarod test (Tox). The result showed that 6-hexyloxy-3,4-dihydro-2 (1H)-quinolinone (5c) was potent in anti-MES and anti-scMet test with ED50 of 24.0 mg/kg and 21.2 mg/kg, respectively, albeit its TD50 (67.6 mg/kg) revealed the high neurotoxicity. 6-Benzyloxy-3,4-dihydro-2(1H)-quinolinone (5f) was less effective against MES induced seizure with ED50 of 29.6 mg/kg, but no neurotoxicity was observed even under 300 mg/kg. Its Protective index (PI) was greater than 10 preferable to Phenytoin, Carbamazepin, Phenobarbital and Valproate.
Kim, Sung-Kwan,Jun, Chang-Soo,Kwak, Kyung-Chell,Park, Kwang-Yong,Chai, Kyu-Yun Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.12
Organic fluorine chemistry produces many useful products. This paper elucidates the reaction of ethyl-4,4- difluoro-2-iodo-5-oxo-5-phenylpentanoate (2) with primary amines in a one-pot scheme. The reaction produced a series of β-fluoropyrrole derivatives at ambient temperatures. In this reaction, the less bulky the primary amine the higher was the resultant yield. When (2) and aqueous methylamine (40%) were allowed to react below 0 oC, 5-(ethoxycarboxyl)-1-methyl-3,3-difluoro-2-hydroxy-2-phenylpyrrolidine, an intermediate molecule for 2-ethyl-4-flouro-1-methyl-5-phenylpyrrole-2-carboxylate (5), was isolated first. Then, (5) reacted with hydroperchloric acid and acetic anhydride to form 5-(ethoxycarboxyl)-1-methyl-3,3-difluoro-2- phenylpyrrolinium perchlorate (6), which was converted to 2-ethyl-4-flouro-1-methyl-5-phenylpyrrole-2- carboxylate gradually in the presence of a base. Our experiments demonstrate that the formation of 2-ethyl-4- flouro-1-methyl-5-phenylpyrrole-2-carboxylate occurs via both one-pot schemes and stepwise pathways, depending on the reaction conditions. The isolation and characterization of the isolated intermediate (6) suggest an anionic pathway for this reaction.
Protective Effects of Chalcone Derivatives for Acute Liver Injury in Mice
Guan Li-Ping,Nan Ji-Xing,Jin Xue-Jun,Jin Qing-Hao,Kwak Kyung Chell,Chai Kyu-yun,Quan Zhe-Shan The Pharmaceutical Society of Korea 2005 Archives of Pharmacal Research Vol.28 No.1
The hepatoprotective effects of chalcone derivatives were evaluated in D-galactosamine/lipopolysaccharide (D-GaIN/LPS)-induced fulminant hepatic failure in mouse. Thirteen chalcone derivatives were synthesized for study and their hepatoprotective effects were evaluated by assessing aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels in serum. Chalcone preparations were injected into mice at 12 hand 1 h before intraperitoneal injection of D-GaIN/LPS. After abdominal administration, changes in AST and ALT between the control and treated groups were observed. Ten of the synthesized chalcone derivatives exhibited inhibitory effects on D-GaIN/LPS-induced levels of AST and ALT in mice. Compounds 2, 3, 8, 9, and 12 markedly reduced serum AST and ALT at 8 h, inhibited hepatocyte necrosis and showed significant hepatoprotective activities. The activity of compound 3 was compared with the bifendate (DDB) through oral administration. Compound 3 showed much higher inhibitory effects than bifendate for decreasing AST and ALT activity. The results indicate that compound 3 has strong hepatoprotective activity through suppression of tumor necrosis factoralpha (TNF-alpha) preduction, reduction of the histological change in the liver, and attenuated of hepatocyte apoptosis confirmed by DNA fragmentation assay.
Ester Derivatives from Tannase-treated Prunioside A and Their Anti-inflammatory Activities
Jun, Chang-Soo,Yoo, Myung-Ja,Lee, Woo-Yiel,Kwak, Kyung-Chell,Bae, Moon-Sung,Hwang, Woo-Taek,Son, Dong-Hwan,Chai, Kyu-Yun Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.1
Prunioside A, isolated from the methanol extract of Spiraea prunifolia var. Simpliciflora's root, is composed of coumaroyl, monoterpene-type, and glucosyl units. The esterase activity of tannase was used to remove the p-coumaroyl and glucopyranosyl groups. The enzymatically hydrolyzed compound was reacted with various acyl chlorides to synthesize its ester derivatives, which showed the inhibitory effects on NO production in murine machrophage?like RAW 264.7 cells stimulated with lipopolysaccharide and interferon-γ.