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K Izawa - One of the best experts on this subject based on the ideXlab platform.

  • Synthesis of 9-(2,3-dideoxy-2-fluoro-beta-D-threo-pentofuranosyl)adenine (FddA) via a purine 3'-deoxynucleoside.
    The Journal of organic chemistry, 2001
    Co-Authors: S Takamatsu, T Maruyama, S Katayama, N Hirose, M Naito, K Izawa
    Abstract:

    A synthesis of 9-(2,3-dideoxy-2-fluoro-beta-D-threo-pentofuranosyl)adenine (1, FddA) via a 6-Chloro-9-(3-deoxy-beta-D-erythro-pentofuranosyl)-9H-purine (9), which was readily obtained from inosine (5), is described. Fluorination at the C2'-beta position of the purine 3'-deoxynucleoside with diethylaminosulfur trifluoride was improved by the introduction of a 6-Chloro Group and proceeded in moderate yield. Purine 3'-deoxynucleoside derivatives were also subjected to nucleophilic reactions with triethylamine trihydrofluoride and gave the desired fluorinated nucleoside in good yield. The safety and yield of the fluorination process were greatly improved by the use of triethylamine trihydrofluoride. The influence of the sugar ring conformation and 6-Chloro Group on the rate of the nucleophilic reaction against elimination are also discussed.

  • Practical synthesis of 9-(2,3-dideoxy-2-fluoro-β-d-threo-pentofuranosyl)adenine (FddA) via a purine 3′-deoxynucleoside
    Tetrahedron Letters, 2001
    Co-Authors: S Takamatsu, T Maruyama, S Katayama, N Hirose, M Naito, K Izawa
    Abstract:

    A synthesis of 9-(2,3-dideoxy-2-fluoro-beta-D-threo-pentofuranosyl)adenine (1, FddA) via a 6-Chloro-9-(3-deoxy-beta-D-erythro-pentofuranosyl)-9H-purine (9), which was readily obtained from inosine (5), is described. Fluorination at the C2'-beta position of the purine 3'-deoxynucleoside with diethylaminosulfur trifluoride was improved by the introduction of a 6-Chloro Group and proceeded in moderate yield. Purine 3'-deoxynucleoside derivatives were also subjected to nucleophilic reactions with triethylamine trihydrofluoride and gave the desired fluorinated nucleoside in good yield. The safety and yield of the fluorination process were greatly improved by the use of triethylamine trihydrofluoride. The influence of the sugar ring conformation and 6-Chloro Group on the rate of the nucleophilic reaction against elimination are also discussed.

Fung Fuh Wong - One of the best experts on this subject based on the ideXlab platform.

  • Selective Synthesis and Photoluminescence Study of Pyrazolopyridopyridazine Diones and N-Aminopyrazolopyrrolopyridine Diones.
    Molecules, 2020
    Co-Authors: Ching-chun Tseng, Cheng-yen Chung, Shuo-en Tsai, Hiroyuki Takayama, Naoto Uramaru, Chin-yu Lin, Fung Fuh Wong
    Abstract:

    The newly designed luminol structures of pyrazolopyridopyridazine diones and N-aminopyrazolopyrrolopyridine diones were synthesized from versatile 1,3-diaryfuropyrazolopyridine-6,8-diones, 1,3-diarylpyrazolopyrrolopyridine-6,8-diones, or 1,3-diaryl-7-methylpyrazolopyrrolopyridine-6,8-diones with hydrazine monohydrate. Photoluminescent and solvatofluorism properties containing UV–Vis absorption, emission spectra, and quantum yield (Φf) study of pyrazolopyridopyridazine diones and N-aminopyrazolopyrrolopyridine diones were also studied. Generally, most of pyrazolopyrrolopyridine-6,8-diones 6 exhibited the significant fluorescence intensity and the substituent effect when compared with N-aminopyrazolopyrrolopyridine diones, particularly for 6c and 6j with a m-Chloro Group. Additionally, the fluorescence intensity of 6j was significantly promoted due to the suitable conjugation conformation. Based on the quantum yield (Φf) study, the value of compound 6j (0.140) with planar structural skeletal was similar to that of standard luminol (1, 0.175).

  • vilsmeier haack reagent promoted formyloxylation of α Chloro n arylacetamides by formamide
    RSC Advances, 2015
    Co-Authors: Jiannjyh Huang, Shihan Lu, Yu Hsuan Chung, Fung Fuh Wong
    Abstract:

    In this study, a Vilsmeier–Haack reagent-promoted formyloxylation of α-Chloro-N-arylacetamides by formamide was developed. The reaction successfully provided the desired α-formyloxy-N-arylacetamides 4 and 7a–n in moderate to excellent yields (70–96%) by use of 3.0 equivalents of PBr3 at 80–90 °C and was applicable to substrates bearing electron-donating or withdrawing Groups at the aryl moiety. For α-Chloro-N-(naphthalenyl)acetamide (8a), α-Chloro-N-(quinolin-8-yl)acetamide (8b), and α-Chloro-N-(thiazol-2-yl)acetamide (8c) possessing the α-Chloro Group, the reaction also provided the desired formyloxylated products 9a–c in 70–87% yields. A plausible mechanism was proposed through the activation of α-Chloroacetamide by the Vilsmeier–Haack reagent to account for the new transformation.

S Takamatsu - One of the best experts on this subject based on the ideXlab platform.

  • Synthesis of 9-(2,3-dideoxy-2-fluoro-beta-D-threo-pentofuranosyl)adenine (FddA) via a purine 3'-deoxynucleoside.
    The Journal of organic chemistry, 2001
    Co-Authors: S Takamatsu, T Maruyama, S Katayama, N Hirose, M Naito, K Izawa
    Abstract:

    A synthesis of 9-(2,3-dideoxy-2-fluoro-beta-D-threo-pentofuranosyl)adenine (1, FddA) via a 6-Chloro-9-(3-deoxy-beta-D-erythro-pentofuranosyl)-9H-purine (9), which was readily obtained from inosine (5), is described. Fluorination at the C2'-beta position of the purine 3'-deoxynucleoside with diethylaminosulfur trifluoride was improved by the introduction of a 6-Chloro Group and proceeded in moderate yield. Purine 3'-deoxynucleoside derivatives were also subjected to nucleophilic reactions with triethylamine trihydrofluoride and gave the desired fluorinated nucleoside in good yield. The safety and yield of the fluorination process were greatly improved by the use of triethylamine trihydrofluoride. The influence of the sugar ring conformation and 6-Chloro Group on the rate of the nucleophilic reaction against elimination are also discussed.

  • Practical synthesis of 9-(2,3-dideoxy-2-fluoro-β-d-threo-pentofuranosyl)adenine (FddA) via a purine 3′-deoxynucleoside
    Tetrahedron Letters, 2001
    Co-Authors: S Takamatsu, T Maruyama, S Katayama, N Hirose, M Naito, K Izawa
    Abstract:

    A synthesis of 9-(2,3-dideoxy-2-fluoro-beta-D-threo-pentofuranosyl)adenine (1, FddA) via a 6-Chloro-9-(3-deoxy-beta-D-erythro-pentofuranosyl)-9H-purine (9), which was readily obtained from inosine (5), is described. Fluorination at the C2'-beta position of the purine 3'-deoxynucleoside with diethylaminosulfur trifluoride was improved by the introduction of a 6-Chloro Group and proceeded in moderate yield. Purine 3'-deoxynucleoside derivatives were also subjected to nucleophilic reactions with triethylamine trihydrofluoride and gave the desired fluorinated nucleoside in good yield. The safety and yield of the fluorination process were greatly improved by the use of triethylamine trihydrofluoride. The influence of the sugar ring conformation and 6-Chloro Group on the rate of the nucleophilic reaction against elimination are also discussed.

Hartmut Fuess - One of the best experts on this subject based on the ideXlab platform.

  • N-(2,5-DiChloro-phen-yl)benzene-sulfonamide.
    Acta Crystallographica Section E Structure Reports Online, 2010
    Co-Authors: B.t. Gowda, Sabine Foro, P.g. Nirmala, Hartmut Fuess
    Abstract:

    In the title compound, C12H9Cl2NO2S, the conformation of the N—H bond is syn to the 2-Chloro Group and anti to the 3-Chloro Group of the aniline benzene ring. The mol­ecule is bent at the S atom with a C—SO2—NH—C torsion angle of 66.4 (2)°. The two rings form a dihedral angle of 73.3 (1)° and an intra­molecular N—H⋯Cl hydrogen bond occurs. The crystal structure features chains linked by N—H⋯O hydrogen bonds.

  • N-(3-Chloro-phen-yl)-4-methyl-benzene-sulfonamide.
    Acta crystallographica. Section E Structure reports online, 2010
    Co-Authors: B.t. Gowda, Sabine Foro, P.g. Nirmala, Hartmut Fuess
    Abstract:

    In the title compound, C(13)H(12)ClNO(2)S, the conformation of the N-H bond is anti to the 3-Chloro Group in the aniline benzene ring. The dihedral angle between the two benzene rings is 73.7 (1)°. The crystal structure features inversion-related dimers linked by pairs of N-H⋯O hydrogen bonds.

  • N-(3-Chlorophenyl)-4-methylbenzenesulfonamide
    Acta Crystallographica Section E Structure Reports Online, 2010
    Co-Authors: B.t. Gowda, Sabine Foro, P.g. Nirmala, Hartmut Fuess
    Abstract:

    In the title compound, C13H12ClNO2S, the conformation of the N—H bond is anti to the 3-Chloro Group in the aniline benzene ring. The dihedral angle between the two benzene rings is 73.7 (1)°. The crystal structure features inversion-related dimers linked by pairs of N—H...O hydrogen bonds

  • 2-Chloro-N-(3-Chloro-phen-yl)benzamide.
    Acta Crystallographica Section E Structure Reports Online, 2008
    Co-Authors: B.t. Gowda, Sabine Foro, B.p. Sowmya, Hartmut Fuess
    Abstract:

    In the structure of the the title compound, C13H9Cl2NO, the N—H and C=O Groups are mutually trans. Furthermore, the conformation of the C=O Group is syn to the ortho-Chloro Group in the benzoyl ring, while the N—H bond is anti to the meta-Chloro Group in the aniline ring. The amide Group forms dihedral angles of 89.11 (19) and 22.58 (37)°, respectively, with the benzoyl and aniline rings, while the benzoyl and aniline rings form a dihedral angle of 69.74 (14)°. The mol­ecules are linked into infinite chains through inter­molecular N—H⋯O hydrogen bonds.

  • 2,2-DiChloro-N-(3-nitro-phen-yl)acetamide.
    Acta Crystallographica Section E Structure Reports Online, 2008
    Co-Authors: B T Gowda, Sabine Foro, Hartmut Fuess
    Abstract:

    The conformation of the N—H bond in the structure of the title compound (3NPDCA), C8H6Cl2N2O3, is anti to the meta-nitro Group, similar to that in the structures of 2-Chloro-N-(3-nitro­phen­yl)acetamide (3NPCA) and 2,2,2-triChloro-N-(3-nitro­phen­yl)acetamide (3NPTCA), and the meta-Chloro Group in 2,2-diChloro-N-(3-Chloro­phen­yl)acetamide (3CPDCA). The geometric parameters of 3NPDCA are similar to those of 2,2-diChloro-N-phenyl­acetamide, 3CPDCA, 3NPCA, 3NPTCA and other acetanilides. Inter­molecular N—H⋯O hydrogen bonds link the mol­ecules into chains running along the b axis.

Vishal Modi - One of the best experts on this subject based on the ideXlab platform.

  • Bent-shaped mesogenic oxadiazole and thiadiazole derivatives from rod-shaped mesogenic hydrazide containing polar Chloro Group
    Liquid Crystals, 2010
    Co-Authors: A. K. Prajapati, Vishal Modi
    Abstract:

    Rod-shaped mesogenic hydrazide (series I) derivatives have been synthesised by the Schotten-Baumann reaction of 4-Chlorobenzhydrazide with 4-n-alkoxybenzoyl chloride using pyridine as a solvent. Rod-shaped mesogenic hydrazide (series I) have been cyclised to bent-shaped mesogenic oxadiazole (series II) and thiadiazole (series III) derivatives using POCl3 and P2S5, respectively. The synthesised compounds are characterised by a combination of elemental analysis and standard spectroscopic methods. All the compounds of present series I–III exhibit smectic A mesophase. The mesomorphic properties of the present series I–III are compared with each other and with the other structurally related mesogenic homologous series to evaluate the effect of bent-shape and different heterocyclic moiety on mesomorphism.