• 제목/요약/키워드: Reductive methylation

검색결과 9건 처리시간 0.022초

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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    • 제17권3호
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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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    • 제17권1호
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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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Ibuproxam의 합성 (Synthesis of Ibuproxam)

  • 최홍대;마정주
    • 약학회지
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    • 제35권2호
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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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Anticancer Agent인 Methotrexate에 대한 새로운 합성 연구 (A New Synthetic Studies on Anticancer Agent Methotrexate)

  • 유의경;류성렬
    • 대한화학회지
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    • 제37권1호
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    • pp.136-140
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    • 1993
  • 새로운 methotrexate 중간체인 diethyl N-[4-{[(2,4-diamino-6-yl)methyl]-amino}benzoyl]-L-glutamate(10)를 합성하기 위하여 p-nitrobenzoic acid를 chlorination한 다음 L-glutamic acid와 coupling하고 이를 esterification한 후, 환원과 methylation시켜 diethyl N-(4-methylaminobenzoyl)-L-glutamate(7)를 합성하였다. 이 화합물(7)을 DMF 존재하에서 NaH와 allyl chloride를 가하여 allylation한 다음 여기에 $IN_3$ addition 반응으로 diethyl-p-[N-(2-azido-3-iodopropyl)-N-methyl]aminobenzoyl-L-glutamate(9)를 합성하였다. 이 화합물(9)을 2,4,5,6-tetraaminopyrimidine hydrochloride와 cyclization시켜 methotrexate diethylester를 얻었다.

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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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    • 제20권10호
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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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    • 제19권9호
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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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    • 제20권7호
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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.

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

  • 채권석;여성문;김학렬
    • 한국동물학회지
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    • 제38권4호
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    • pp.490-497
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    • 1995
  • 미국흰불나방 의지방체 조직을 [35S]-메타이오닌이 포하된 배지에서 조직배양한 결과, 저장단백질-1(SP-1)의 전용기부터 용 1일 사이에 지방체로 흡수됨을 알았다. CHAPS, Triton X-100 등의 계면활성제를 농도별로 처리하여 막단백질의 용해도를 스크리닝한 뒤, anti-SP-1 polyclonal 항체를 쓴 Western blotting과 ligand blotting, 그리고 in vitro reductive methylation으로 14C을 표지한 저장단백질-1을 사용한 fluorography 등으로 1개의 수용체 밴드를 확인하였다. 1% Triton X-100으로 용해시킨 부분정제하였고, SDS-PAGE에 의해서 분자량을 측정한 결과 약 80 kDa로 나타났고 isoelectric focusing 시행 결과 등전점은 약 6.1로 계산되었다. 수용체 분자는 환원조건과 비환원조건의 차이와 전기영동 중의 온도에 따라서 SDS-PAGE상의 뚜렷한 밴드 양상의 차이를 나타내었다.

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