• Title/Summary/Keyword: Thio analogues

Search Result 5, Processing Time 0.02 seconds

Thio and Nitrogen Analogues of Acronycine

  • Geewananda, Y.A.;Gunawardana, P.;Cordell, Geoffrey A.
    • Archives of Pharmacal Research
    • /
    • v.18 no.3
    • /
    • pp.195-202
    • /
    • 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.

  • PDF

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 (카보닐 탄소원자 친핵 치환반응. 제2보. Methyl chloroformate의 티오 치환제들의 구조와 반응성에 관한 CNDO/2 계산)

  • Lee Ikchoon
    • Journal of the Korean Chemical Society
    • /
    • v.16 no.6
    • /
    • pp.334-340
    • /
    • 1972
  • CNDO/2 calculations have been carried out on methyl chloro-thiol-, methyl chloro-thiono-, and methyl chloro-dithio-formates. Results show that the trans is the stable configuration for these compounds. It was found that sulfur atom has much less tendency to use its lone pair electrons for ${\pi}$ bond formation compared with oxygen, and that thiolformates are stabilized by hyperconjugation of methyl hydrogens. The order of solvolytic reactivity was found to follow the order of cation stability, which is consistent with the $S_N1$ mechanism proposed for these compounds.

  • PDF

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
    • /
    • v.31 no.4
    • /
    • pp.863-868
    • /
    • 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
    • /
    • v.27 no.5
    • /
    • pp.502-506
    • /
    • 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
    • /
    • v.18 no.1
    • /
    • pp.14-18
    • /
    • 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.