• Title/Summary/Keyword: Reductive methylation

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An Improved Synthesis of Methyl p-Hydroxyphenylalkanoates

  • Choi, Hong-Dae;Kowak, Yong-Sil;Geum, Dak-Hyun;Son, Byeng-Wha
    • Archives of Pharmacal Research
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    • v.17 no.3
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    • pp.190-193
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    • 1994
  • Friedel-Crafts reaction isopropoxybenzene with methyl $\alpha$-chloro-$\alpha$-(maethylthio)acetate 1 afforded methyl $\alpha$-methylthio-p-isopropoxyphenylacetate 2d, which was readily converted into methyl p-isopropoxyphenylacetate 3 by reductive desulfurization with zinc dust in acetic acid. Methylation of 3 with sodium hydride and methyl iodide gave methyl $\alpha$-(p-isopropoxyphenyl)propionate 5. Methyl p-hydroxyphenylakanoates (4,6), useful intermediates for some medicines, were easily prepared by treatment of 3 and 5 with titanium tetrachloride, respectively.

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Synthesis of 2-(2-Fluorenyl)propanoic Acid

  • Choi, Hong-Dae;Geum, Dek-Hyun;Kowak, Young-Sil;Son, Byeng-Wha
    • Archives of Pharmacal Research
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    • v.17 no.1
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    • pp.17-20
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    • 1994
  • Friedel-Crafts reaction of fluorene with methyl ${\alpha}$-chloro-${\alpha}$-(methylthio)acetate 1 gave methyl $\alpha$-methylthio-2-fluoreneacetate 2. Cicloprofen 8, a potent antiinflammatory agent, was prepared by methylation of 2 followed by reductive desulfurization of methyl 2(2-fluorenyl)-2-(methylthio)propionate 6 and hydrolysis of methyl 2-(2-fluorenyl)propionate 7.

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Synthesis of Ibuproxam (Ibuproxam의 합성)

  • 최홍대;마정주
    • YAKHAK HOEJI
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    • v.35 no.2
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    • pp.119-122
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    • 1991
  • A convenient method for the synthesis of ibuproxam, which is a non steroidal antiinflammatory agent, is reported. Friedel-Crafts reaction of isobutylbenzene with ethyl $\alpha$-chloro-$\alpha$-(methylthio)acetate (3) gives ethyl $\alpha$-methylthio-(p-isobutylpheny) acetate (4). Ethyl 2-methylthio-2-(4-isobutylphenyl) propionate (5) is obtained from methylation of the compound (4) with NaH and Mel. lbuproxam (7) is easily synthesized by reductive desulfurization of the compound (5) with zinc dust-acetic acid or Raney nickel, followed by treatment of the resultant ethyl 2-(4-isobutyl-pheny) propionate (6) with H$_{2}$NOH-HCI.

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A New Synthetic Studies on Anticancer Agent Methotrexate (Anticancer Agent인 Methotrexate에 대한 새로운 합성 연구)

  • Yu Euy Kyung;Ryu Seoung Ryuall
    • Journal of the Korean Chemical Society
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    • v.37 no.1
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    • pp.136-140
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    • 1993
  • New synthetic method for diethyl N-[4-{[(2,4-diamino-6-yl)methyl]-amino}benzoyl]-L-glutamate(10) which is an intermediate of methotrexate is described. p-Nitrobenzoyl-L-glutamate was obtained via a two-step sequence which involves condensation of p-nitrobenzoyl chloride with diethyl-L-glutamate and Fischer esterification reaction with ethanol. Reductive methylation of diethyl-p-nitrobenzoyl-L-glutamate were carried out by reaction with formic acid and paraformaldehyde in the presence of $PtO_2$ catalyst and yielded diethyl N-(4-methylaminobenzoyl)-L-glutamate(7). It was followed by allylation and iodoazidozation to give the diethyl-p-[N-(2-azido-3-iodopropyl)-N-methyl]aminobenzoyl-L-glutamate(9). The cyclization reaction of compound(9) with 2,4,5,6-tetraaminopyrimidine was carried out by intermolecular nucleophilic substitution to give the desired methotrexate diethylester.

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Determination of Relative Reactivities of Free Hydroxyl Groups in β-Cyclodextrin, Amylose, and Cellulose by Reductive-Cleavage Method

  • 이창규;김은주;전중호
    • Bulletin of the Korean Chemical Society
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    • v.20 no.10
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    • pp.1153-1158
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    • 1999
  • β-Cyclodextrin, amylose, and cellulose were partially methylated and acetylated in order to examine the relative reactivities of 2-, 3-, and 6-OH groups to alkylation and acylation. The partially methylated samples of the polysaccharides were treated with excess of ethyl iodide and sodium hydroxide in dimethyl sulfoxide to convert all of the free hydroxyl groups to ethyl ether groups. The partially O-ethylated and O-methylated polysaccharides were reductively cleaved with triethylsilane in the presence of trimethylsilyl methanesulfonate and borontrifluoride etherate (5 : 1 by mole) and the resulting 4-OH group was acetylated and benzoylated to form mixtures of eight 4-O-acyl-1,5-anhydroalditols. The relative ratio of the alditol esters were analyzed by gas chromatography to determine the degree of substitution at each position. A similar sequence of reactions was carried out with partially acetylated polysaccharides. The results indicated that the order of relative reactivities for methylation are 2-OH > 6-OH > 3-OH and for acylation are 6-OH > 2-OH > 3-OH regardless of the anomeric configuration.

Study of Macrophage Activation and Structural Characteristics of Purified Polysaccharides from the Fruiting Body of Hericium erinaceus

  • Lee, Jong-Seok;Min, Kyoung-Min;Cho, Jae-Youl;Hong, Eock-Kee
    • Journal of Microbiology and Biotechnology
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    • v.19 no.9
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    • pp.951-959
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    • 2009
  • Most, if not all, Basidiomycetes mushrooms have biologically active polysaccharides showing potent antitumor activity with immunomodulating properties. These polysaccharides have various chemical compositions and belong primarily to the $\beta$-glucan group. In this study, the crude water-soluble polysaccharide HEF-P, which was obtained from the fruiting body of Hericium erinaceus by hot water extraction and ethanol precipitation, was fractionated by DEAE-cellulose and Sepharose CL-6B column chromatographies. This process resulted in four polysaccharide fractions, named HEF-NP Fr I, HEF-NP Fr II, HEF-AP Fr I, and HEF-AP Fr II. Of these fractions, HEF-AP Fr II was able to upregulate the functional events mediated by activated macrophages, such as production of nitric oxide and expression ofcytokines (IL-1${\beta}$ and TNF-${\alpha}$). The molecular mass of HEF-AP Fr II was estimated by gel filtration to be 13 kDa. Its structural characteristics were investigated by a combination of chemical and instrumental analyses, including methylation, reductive cleavage, acetylation, Fourier transform infrared spectroscopy (FT-IR), and gas chromatography-mass spectrometry (GC-MS). Results indicate that HEF-AP Fr II is a low-molecular-mass polysaccharide with a laminarin-like triple helix conformation of a ${\beta}$-1,3-branched-${\beta}$-1,6-glucan.

Study of Macrophage Activation and Structural Characteristics of Purified Polysaccharide from the Fruiting Body of Cordyceps militaris

  • Lee, Jong-Seok;Kwon, Jeong-Seok;Won, Dong-Pil;Lee, Jung-Hyun;Lee, Keun-Eok;Lee, Shin-Young;Hong, Eock-Kee
    • Journal of Microbiology and Biotechnology
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    • v.20 no.7
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    • pp.1053-1060
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    • 2010
  • Cordyceps militaris, an entomopathogenic fungus belonging to the class Ascomycetes, has been reported to have beneficial biological activities such as hypoglycemic, anti-inflammatory, antitumor, antimetastatic, hypolipidemic, immunomodulatory, and antioxidant effects. In this study, the crude water-soluble polysaccharide CMP, which was obtained from the fruiting body of C. militaris by hot water extraction and ethanol precipitation, was fractionated by DEAE-cellulose and Sepharose CL-6B column chromatographies. This process resulted in three polysaccharide fractions, termed CMP Fr I, CMP Fr II, and CMP Fr III. Of these fractions, CMP Fr II, with an average molecular mass of 127 kDa, was able to upregulate effectively the phenotypic functions of macrophages such as NO production and cytokine expression. The chemical property of the stimulatory polysaccharide, CMP Fr II, was determined based on its monosaccharide composition, which consisted of glucose (56.4%), galactose (26.4%), and mannose (17.2%). Its structural characteristics were investigated by a combination of chemical and instrumental analyses, including methylation, reductive cleavage, acetylation, Fourier transform infrared spectroscopy (FTIR), and gas chromatography-mass spectrometry (GCMS). Results indicated that CMP Fr II consisted of the (1${\rightarrow}$4) or (1${\rightarrow}$2) linked glucopyranosyl or galactopyranosyl residue with a (1${\rightarrow}$2) or (1${\rightarrow}$6) linked mannopyranosyl, glucopyranosyl, or galactopyranosyl residue as a side chain. The configuration of the ${\beta}$-linkage and random coil conformation of CMP Fr II were confirmed using a Fungi-Fluor kit and Congo red reagent, respectively.

Characterization and Partial Purification of Storage Protein-i Receptor in the Fat Body of Hyphantria cunea (미국흰불나방 지방체에서 저장단백질-1의 수용체의 특성과 부분정제)

  • 채권석;여성문;김학렬
    • The Korean Journal of Zoology
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    • v.38 no.4
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    • pp.490-497
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    • 1995
  • In vitro tissue culture of fat body of Hyphantria cunea in the medium containing [35S]-methionine reveaied that storage protein-i (SP-1) is taken up into fat body of prepupae and 1-day-old pupae. Using Western blotting and ligand binding method, we were able to identify the protein band of the SP-1 receptor protein. For the partial purification, the membrane proteins of fat body cells were solubilixed with 1% Triton X-1OO and applied to anion exchange chromatography. The results revealed the molecular weight of the receptor protein to be about 80 kl)a in SDSPAGE, and the P1 was estimated to be about 6.1. The mobility of the receptor protein in 8D8-PAGE was highly dependent on both temperature during electrophoresls and the condition of samples whether they were in reducing or nonreducing.

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