• 제목/요약/키워드: Thio analogues

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Thio and Nitrogen Analogues of Acronycine

  • Geewananda, Y.A.;Gunawardana, P.;Cordell, Geoffrey A.
    • Archives of Pharmacal Research
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    • 제18권3호
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    • pp.195-202
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    • 1995
  • The thio, thio acetyl, oxime, and several hydrazone and azine derivatives of the antitumor alkaloid acronycine (1) were prepared. NMR spectroscopy was used to study the configurations around the C=N double bond in these acronycine derivatives. In the hydrazones and azines of acronycine the N-N bond assumes a syn configuration to the $C_6-OCH_3$ group, while the NO bond in the oxime and the N-N bond in noracronycine hydrazone and azines assumes an anti configuration.

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카보닐 탄소원자 친핵 치환반응. 제2보. Methyl chloroformate의 티오 치환제들의 구조와 반응성에 관한 CNDO/2 계산 (Nucleophilic Substitution at a Carbonyl Carbon Atom. Part II. CNDO/2 Studies on Conformation and Reactivity of the Thio-Analogues of the Thio-Analogues of Methyl Chloroformate)

  • 이익춘
    • 대한화학회지
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    • 제16권6호
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    • pp.334-340
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    • 1972
  • 메틸 클로로 티올, 메틸클로로 티오노 및 메틸 클로로 디티오 훠메이트에 대하여 CNDO/2 계산을 실시하였다. 결과로 이들 화합물은 trans형이 안정한 것임을 밝혔다. 또 유황 원자는 산소원자에 비하여 그 고립쌍 전자들을 ${\pi}$-결합 형성에 사용하려는 경향이 적고 티올 훠메이트의 경우는 메틸기의 hyperconjugation에 의하여 안정화됨을 알았다. 가용매 반응성의 순서는 양이온의 안정도와 일치하며 이것은 알려진 $S_N1$형 반응 메카니즘과 부합된다.

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A Convenient One-Pot Biginelli Reaction Catalyzed by Y(OAc)3: An Improved Protocol for the Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones and Their Sulfur Analogues

  • Aridoss, Gopalakrishnan;Jeong, Yeon-Tae
    • Bulletin of the Korean Chemical Society
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    • 제31권4호
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    • pp.863-868
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    • 2010
  • Yttrium(III) acetate hydrate-catalyzed novel synthesis of 3,4-dihydropyrimidin-2(1H)-(thio)one derivatives was achieved through one-pot three-component condensation of diversified aldehydes, $\beta$-ketoesters and urea or N-methylurea or thiourea with a molar ratio of 1:1:1.4. In comparison to the classical Biginelli approach, this catalytic method has the advantages of short reaction time and improved product yield.

Antituberculosis Agents X. Synthesis and Evaluation of In Vitro Antituberculosis Activity of 2-(5-Nitro-2-furyl)-and 2-(1-Methyl-5-nitro-1H-imidazol-2-yl)-1 ,3,4-thiadiazole Derivatives

  • Alireza-Foroumadi;Fatemeh-Soltani;Raheleh-Jabini;Moshafi, Mohammad-Hasan;Rasnani, Fatemeh-Mohammadian
    • Archives of Pharmacal Research
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    • 제27권5호
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    • pp.502-506
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    • 2004
  • Two series of 2-(5-nitro-2-furyl)- and 2-(1-methyl-5-nitro-1H-imidazol-2-yl)-5-propyl, allyl and propargyl)thio-1,3,4-thiadiazoles (6a-f) and 2-(5-nitro-2-furyl)- and 2-(1-methyl-5-nitro-1 H-imidazol-2-yl)-5-(nitrobenzyl)thio-1,3,4-thiadiazole derivatives (8a-f) have been synthesized and evaluated against Mycobacterium tuberculosis, as part of the TAACF TB screening program under direction of the US National Institute of Health, the NIAID division. Primary screening was conducted at a single concentration, 6.25 $\mu\textrm{g}$mL$^{-1}$ , against M. tuberculosis H$_{37}$ Rv in BACTEC 12B medium, using the Microplate Alamar Blue Assay (MABA). The minimum inhibitory concentration (MIC) was determined for the compounds that demonstrated $\geq$90% growth inhibition in the primary screening. A varying degree of antituberculosis activity (from 0-97% of growth inhibition) was observed with the alkylthio series (6a-f), and the nitroimidazole derivative with a propylthio group (6b) and the nitrofuran derivative with a propargylthio group (6e), were the most active compounds (MIC=3.13 and 1.56 /$\mu\textrm{g}$mL$^{-1}$ , respectively). Among the nitrobenzylthio derivatives (8a-f), all the ortho, meta and para nitrobenzyl isomers in the nitrofuran series exhibited good antituberculosis activity (MIC=3.13 $\mu\textrm{g}$mL$^{-1}$ ), while the corresponding nitroimidazole analogues were completely inactive (Inhibition=0%).

The Structure of 1-[2-[[(4-chlorophenyl)-methyl]thio]-2-(2, 4-dichlorphenyl)ethyl]-1H imidazole (Sulconazole) nitrate, C18H16Cl3N3O3S

  • Shin, Hyun-So;Song, Hyun;Cho, Sung-Il;Pakr, Keun-Il
    • Bulletin of the Korean Chemical Society
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    • 제18권1호
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    • pp.14-18
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    • 1997
  • Sulconazole nitrate, C18H16Cl3N3O3S, crystallizes in monoclinic, space group C2/c, with a=14.401(1), b=8.051(1), c=34.861(2) Å, β=95.9(1)°, g=0.58 mm-1, Dc=1.523 g/cm3, Dm=1.522 g/cm3, F(000)=1888.0, and z=8. Intensities for 2460 unique reflections were measured on a CAD4 diffractometer with graphited-monochromated Mo-Kα radiation. The structure was solved by direct method and refined by full matrix least squares to a final R=0.071 for 2182 reflections (Io > 2σIo). The bond lengths and angles are comparable with the values found in the analogues imidazole derivatives. The 2,4-dichlorophenyl ring(A) and the p-chlorophenyl ring(B) are almost planar with different heights [dihedral angle 17.3°] while the imidazole ring(C) is nearly perpendicular to the two phenyl rings[dihedral angles about the two rings A, B are 110.8° and 96.1° respectively]. In order to understand the overall conformation we calculated the selected distances (l1, l2, l3) among the center of the three rings and considered the imaginary plan D[C(7), C(9) and C(16)]. The two polar group S(8) and N(19) do not have gauche conformation and l2 value (4.47 Å) is shorter than the other imidazole derivatives. One -NO3 group are hydrogen bonded the two neighbored sulconazole molecules. The molecular crystal packing is also formed by two hydrogen bondings and van der Waals forces.