• Title/Summary/Keyword: $C_8$-methoxy

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Oxidation of Benzyl Ethers in Sodium Hypochlorite Mediated Piperidine-1-oxyl System (촉매량의 Piperidine-1-oxyl과 NaOCl계에서 벤질 에테르 유도체들의 산화 반응)

  • Cho, Nam Sook;Park, Chan Heun
    • Journal of the Korean Chemical Society
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    • v.39 no.8
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    • pp.657-665
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    • 1995
  • The oxidation of various benzyl ethers and benzyl alkyl ethers to benzoates has been studied in two-phase system of $CH_3CO_2Et$ and aqueous NaOCl (6.6 mol eq.). The oxidant N-oxo-4-methoxy-2,2,6,6-tetramethylpiperidium bromide (N-oxoammonium salt) was prepared in situ and recycled by addition of 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl (0.03 mol eq., 4-methoxy-TEMPO), co-catalyst KBr (0.03mol eq.) and second oxidant NaOCl. Thus the catalytic amount of 4-methoxy-TEMPO was used. An adjustment of the pH value of below 8.0 was also required for this reaction with 2.5 hr of reaction time at 0∼5$^{\circ}C$. Under these conditions benzyl ethers were oxidized to benzoates. The selectivity of oxidation of benzyl alkyl ethers is dependent on the acidity of hydrogen and steric effect of alkyl group.

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Crystal Structure of 1-Cyclopropyl-7-(2,7-diazabicyclo[3.3.0]oct-4-en-7-yl)-6-fluoro-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (HCI salt) (1-Cyclopropyl-7-(2,7-diazabicyclo[3.3.0]oct-4-en-7-yl)-6-fluoro-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid 염산염의 결정구조)

  • 김문집;신준철
    • Korean Journal of Crystallography
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    • v.6 no.2
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    • pp.103-110
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    • 1995
  • The crystal structure of 1-Cyclopropyl-7-(2,7-diazabicyclo[3.3.0]oct-4-en-7-yl)-6-fluoro-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (HCI salt) has been determined from single crystal x-ray diffraction study ; C20H21N3O4FCl, Monoclinic, C2/c, a=28.349(2)Å, b=11.941(2)Å, c=12.806(2)Å, β=96.428(9)°, V=4307.8Å3, T=296(2)K, Z=8, CuKα(λ=1.5418Å). The molecular structure was solved by direct method and refined by full-matrix least squares to a final R=4.96% for 2258 unique observed F0>4σ(F0) reflections and 293 parameters. The conformation of the molecule is stabilized by an intramolecular O(28)-H(28)…O(25) [2.517(4)Å, 156.7(447)°] hydrogen bond. Intermoleculars distances correspond to van der Waals contacts.

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A Study of Antibacterial Activity of Some Novel 8-Methoxy-4-methyl-quinoline Derivatives

  • Singh, Sheoraj;Kumar, Vikas;Kumar, Ashok;Sharma, Shalabh;Dua, Piyush
    • Bulletin of the Korean Chemical Society
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    • v.31 no.12
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    • pp.3605-3610
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    • 2010
  • In the present study, some quinoline derivatives have been synthesized like 8-methoxy-4-methyl-2-amino-(3'-chloro-2'-oxo-4'-substituted aryl-1'-azetidinyl)quinolines 8-12 and 8-methoxy-4-methyl-2-amino-(2'-substituted aryl-4'-oxo-1',3'-thiazolidin-3'-yl) quinolines 13-17 from 8-methoxy-4-methyl-2-(substituted arylidenyliminoamino)-quinolines 3-7. The structural assignments of these compounds were based on spectral (IR, $^1H$-NMR, Mass) and elemental (C, H, N) analysis. Further, these compounds were evaluated for antibacterial activity against various bacterial strains. Three compounds 10, 11 and 16 were found to exhibit potent antibacterial activity as compared to the standard drug amphicillin.

Polyoxygenated Flavones; Synthesis, Cytotoxicities and Antitumor Activity against ICR Mice Carrying S-180 Cells

  • Song, Gyu-Yong;Ahn, Byung-Zun
    • Archives of Pharmacal Research
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    • v.18 no.6
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    • pp.440-448
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    • 1995
  • Fitty two flavones were synthesized from polyoxygenated dibenzoylmethanes which were obtained by a modified Baker-Venkatarman rearrangement, of 2-benzoyl oxyacetophenones. The following flavones among them showed good cytotoxic activities against L1210 and HL60 cells ; 2'-benzoyloxy-5,7-dimethoxyflavone $(8.2{\mu}g/ml,{\;}5.0 {\mu}g/ml)$, 2'-benzyloxy-5,7,8-trimethoxyflavone $(5,9 {\mu}g/ml,{\;}11.0{\mu}g/ml,{\;}2.7{\mu}g/ml)$, 2'-hydroxy-5,7,8-trimethoxyflavone $(9.8{\mu}/ml,{\;}6.2{\mu}g/ml)$, 2'-benzyloxy-5-hydroxyflavone $(5.2 {\mu}g/ml,{\;}3.6{\mu}g/ml)$, and 5,2'-dihydroxyflavone $(5.1{\mu}g/ml,{\;}4.0{\mu}g/ml)$. Presence of 5-methoxy group potentiated the cytotoxic activity, while the existence of 7-methoxy group decreased the activity. 5-Hydroxy or methoxy activates 4-carbonyl group, while 7-methoxy group deactivates the acrbonyl group. From these observation it was concluded that the activation of carbonyl group at C-4 of a flavone is important for the enahncement of the cytotoxic activity. The presence of both 5-hydroxy and 2-benzyloxy-or 2-hydroxy group enhanced the antitumor activity; 2'-benzyloxy-5-hydroxy-7-methoxyflaone 9T/C=144%), 5.2'-dihydroxy-7-methoxyflavone (T/C=132%) and 5,2'-dihydroxy-6,78,6' trtramethoxyflvone (T/C = 172%) 2'hexanolytion of 5,2'-dihydroxy-flavones did not improve the natitumor activity; 2' hexanoyloxy-5-hydroxy-7-methoxyflavone showed T/C = 132%, about the same as that of 5,2'-dihydroxy-7-methoxyflvone (T/C=130%)

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Thermolysis Reactions of 2-Methoxy-2-(o-N,N-dimethylminometiyl)-phenyl-3-tiimetiylsilyl-5,5-dimetiyl-2-silahexane

  • Lee, Myeong Ui;Jo, Hyeon Mo;Kim, Chang Hwan
    • Bulletin of the Korean Chemical Society
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    • v.21 no.8
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    • pp.793-796
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    • 2000
  • In the neat flow vacuum pyrolysis of 2-methoxy-2-(o-N,N+dimethylaminomethyl)phenyl-3-trimethylsilyl-5,5-dime-thyl-2-silahexane (4) at $600^{\circ}C$ and its static thermolysis at $350^{\circ}C23-benzo-5-aza-1-silacyclohexane$, (5) has been obtained in97% and 46% y ields, respectively. Product 5 might have been formed via an intramolecular rearrangement invoIving a zwitterionic species generated from the pentacoordinated silene Si-atom. From trapping experiments with an excess of MeOH, we have obtained 2-(o-N,N-dimethylaminomethyl)phenyl-5,5-dimethyl-2-trimethylsiloxy-2-silahexane (6) and 2-(o-N,N-dimethylaminomethyl)phenyl-2-methoxy-5,5-dime-thyl-2-silahexane (7) formed via an intermolecular protodesilylation reaction rather than through trapped prod-ucts of the silene.

A New Furocoumarin from the Leaves of Camellia sinensis(L.) O. Kuntze

  • Banerjee, Jayashree;Ganguly, S.N.
    • Natural Product Sciences
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    • v.3 no.1
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    • pp.11-13
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    • 1997
  • From the methanolic extract of defatted tender leaf of Camellia sinensis a new 4-hydroxy angular furocoumarin $C_{12}H_8O_5$, m.p. $212^{\circ}C$, was isolated using high-speed counter-current chromatographic technique. The structure of the compound was established as 4-hydroxy-2'-methoxy angular furocoumarin on the basis of physical methods viz. $^1H$ NMR, $^{13}C$ NMR and MS.

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Synthesis and Insecticidal effects of 2,2-bis(2-methoxy-5-chlorophenyl) 1,1,1-trichloroethane (2,2-bis(2-methoxy-5-chlorophenyl) 1,1,1-trichloroethane의 合成 과 殺蟲能에 관하여)

  • Lee, Dae-Soo;Kim, Jae-Hang;Choi, Won-Hyung;Choi, Young-Euion
    • Journal of the Korean Chemical Society
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    • v.10 no.4
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    • pp.149-152
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    • 1966
  • An insecticide was obtained by condensation of chloral hydrate with p-chloroanisole. The structure of the insecticide was found to be 2,2-bis(2-methoxy-5-chlorophenyl)1,1,1-trichloroethane(M.C.T.). The best conditions for this condensation reaction were as follows: 1) The sulfuric acid concentration: 93% 2) The mole ratio of sulfuric acid to p-chloroanisole: 8 3) The mole ratio of chloral hydrate to p-chloroanisole: 0.7 4) The reaction time and reaction temperature: 12 hrs and 25-30$^{\circ}C$ The insecticidal effects of M.C.T against the Citrus Red Mite and Chrysanthemum Aphid were five times as strong as D.D.T.

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Chemical Constituent of Aloe capensis

  • Park, Man-Ki;Park, Jeong-Hill;Shin, Young-Geun;Choi, Yong-Seok;Kim, Kyeong-Ho;Cho, Tae-Hyeong;Lee, Seung-Ki
    • Archives of Pharmacal Research
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    • v.20 no.2
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    • pp.194-196
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    • 1997
  • A C-glycosyl chromone, named as 7-O-methylaloesinol, was newly isolated from the leaf exudate of Aloe capensis and identified as $8-C-{\beta}-D-glucopyranosyl$${\beta}-2-[2-(R)-hydroxypropyl]-7-methoxy-5-methyl-4H-1-benzopyran-4-one$ by chemical and spectral evidence.

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Syntheses of Alternating Head-to Head Vinyl Copolymers and Vinyl Terpolymers via Ring-Opening Mechanism. Ring-Opening Polymerization of Substituted-3,4-dihydro-2H-pyrans

  • Lee, Ju-Yeon;Cho, I-Whan
    • Bulletin of the Korean Chemical Society
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    • v.8 no.2
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    • pp.96-101
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    • 1987
  • 2-Ethoxy-6-methoxy-5-cyano-3,4-dihydro-2H-pyran (1_a$), 2-n-butoxy-6-methoxy-5-cyano-3,4-dihydro-2H-pyr an (1b), 2-isobutoxy-6-methoxy-5-cyano-3,4-dihydro-2H-py ran ($1_c$), and 2-ethoxy-6-methoxy-3-methyl-5-cyano-3,4-dihydro -2H-pyran ($1_d$) were prepared by (4 + 2) cycloaddition reaction of methyl $\alpha$-cyanoacrylate with the corresponding alkyl vinyl ethers. Compounds $1_{a-d}$ were ring-open polymerized by cationic catalyst to obtain alternating head-to-head (H-H) copolymers. For comparison, head-to-tail (H-T) copolymer $3_a$ was also prepared by free radical copolymerization of the corresponding monomers. The H-H copolymer exhibited minor differences in its $1_H% NMR and IR spectra, but in the $^{13}C$ NMR spectra significant differences were observed between the H-H and H-T copolymers. Glass transition temperature ($T_g$) of H-H copolymer was higher than that of the H-T copolymer, but thermal decomposition temperature of the H-H copolymer was lower than that of the H-T copolymer. Compounds $1_a$, $a_b$, and $1_c$, copolymerized well with styrene by cationic catalyst, but compound 1d failed to copolymerize with styrene. All of the H-H and H-T copolymers were soluble in common solvents and the inherent viscosities were in the range 0.2-0.4 dl/g.

Studies on the Synthesis of Protoberberine Related Compounds and its Activities (프로트베르베린 관련화합물 합성 및 활성검토)

  • 황순호;임형엽;우성주;김재현;김동현;김신규
    • YAKHAK HOEJI
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    • v.39 no.1
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    • pp.36-40
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    • 1995
  • In order to investigate the biological activity of protoberberine derivatives, they were synthesized four derivatives (1-4) of 7,8 adduct of cycloberberine, two derivatives (5, 6) treated with alkylamine or phenylamine, four compounds (7, 8) and (9, 10) adduct with 1,3-dichloroacetone and oxalychloride. Antibacterial activity of these synthesized compounds was tested.

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