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151.
152.
Mitsuji Yamashita Lakonda Nagaprasada Rao Valluru Krishna Reddy Motoki Maeda Tatsuo Oshikawa Masaki Takahashi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6-7):1661-1665
Novel pentofuranose analogs of phospha sugar derivatives were synthesized starting from 1-phenyl-2-phospholene 1-oxide ( 1 ). First, the allylic oxidation of 1-phenyl-2-phospholene 1-oxide ( 1 ) with CrO 3 in Ac 2 O-AcOH or 3-hydroxy-1-phenyl-2-phospholene ( 2 ) with MnO 2 afforded 1-phenyl-4-oxo-2-phospholene 1-oxide ( 3 ). The C-5 alkylation of 3 in the presence of NaH by using benzyl bromide or methyl iodide as electrophiles afforded the target title compounds. 相似文献
153.
Krishna C. Joshi Diwakar Sharma Bidya S. Joshi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):33-36
Abstract The synthesis of some new sulfur-containing spiroindole derivatives is reported. Fluorinated 3′-aryl-2′-phenylimino-spiro[3H-indole-3,6′[4,5′-pyrazolin][4,3-d]thiazolo]2(1H)-ones were prepared by the reaction of 5-(2-oxo-3-indolinylidene)-3-aryl-2-phenylimino-4-thiazolidinones with hydrazine hydrate. The compounds have been characterized on the basis of elemental and spectral studies. 相似文献
154.
Harika Patnala Hanna S. Abbo Krishna Murthy Potla 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):1035-1039
AbstractAn efficient and eco-friendly protocol has been accomplished for a series of novel α-diaminophosphonates by a one-pot, three-component system via Kabachnik-Fields reaction of 4,4′-methylenedianiline, a variety of aryl/heteroaryl aldehydes and diphenylphosphite employing polyethylene glycol (PEG-400) as a green solvent at 80?°C. All products were obtained in good to excellent yields (80–95%). The identity of the new synthesized compounds was confirmed by IR, 1H, 13C, and 31P NMR, LC-MS and elemental analysis. In vivo anti-viral activity was evaluated against tobacco mosaic virus (TMV). Compounds 4b, 4c, 4j and 4k exhibited the highest anti-viral activities against tobacco mosaic virus (TMV) when compared with the standard drug ningnanmycin. 相似文献
155.
Abstract The kinetics of the radical copolymerization of acrylonitrile with methyl acrylate complexed by zinc chloride (ZnCl2) in dimethylformamide (DMF) was investigated at 60, 65, and 70°C. The kinetic data revealed that Rp was an inverse function of ZnCl2 concentration and directly related to monomers concentration. The increase in the activation energy from 11.85 to 19.25 kJ·mol?1 and the decrease in the value of the ratio of the propagation to termination rate constants (kp 2/kt ) from 0.08 to 0.06 L·mol?1·s?1 on the addition of ZnCl2 indicated its retarding effect. The chain transfer constant of DMF for the system was 16.25 × 10?4, accordingly the degree of polymerization decreased. The structure and composition of the copolymers determined by 1H-NMR and elemental analysis was found to be alternating. The nonideal behavior of the glass transition temperatures determined by DSC also favors the alternation of monomer units in the copolymer. The reaction proceeds via a cross-propagation mechanism. 相似文献
156.
Vishwanath Bhat H. R Shivakumar Rai K. Sheshappa Sanjeev Ganesh P. Prasad G. S. Guru 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(11):920-926
Blends of Pullulan (PU) and Polyacrylamide (PAM) having biomedical applications were prepared and characterized in order to evaluate the miscibility of natural component with the synthetic one. Blends with different composition ratios were prepared using water as common solvent. Viscosity, ultrasonic velocity and density were measured at 30 and 40°C. Furthermore, the blend films were prepared by a solution casting method and analyzed by DSC, FTIR and TGA methods. Results of ultrasonic and density methods revealed the semi-miscibility of the blend. Using viscosity data, interaction parameters (Chee's ‘μ’ and Sun's ‘α’) were computed. The values confirmed that the blend is miscible when the Pullulan content is less than 20% in the blend. Change in temperature had no effect on the miscibility nature of the blends. Intermolecular interactions of hydrogen bonding type were confirmed by DSC and FTIR methods. Thermal behavior of blends was investigated using TGA method. 相似文献
157.
Abstract The films of poly(4,4′-cyclohexylidene diphenylene-m-benzene disulfonate) (PSBB, 0.610 mm thick) and poly(4,4′-cyclohexylidene diphenylene-toluene-2,4-disulfonate) (PSBT, 0.537 mm thick) showed 8.23 ± 0.25 and 9.6 ± 0.245 kV, respectively, as the dielectric breakdown voltage (ac) in air at room temperature. The same films have 8.8 × 1011 and 7.2 × 1014 ω°Cm volume resistivity. PSBB (40 μm thick) and PSBT (50 μm thick) films have tensile strengths of 1971 and 1677 kg/cm2 and percent elongations of 1.3 and 1.2, respectively. The static hardnesses of PSBB (0.178 mm thick) and PSBT (0.190 mm thick) at three different loads (15–60 g) are 12.8–15.5 and 14.5–16.5 kg/mm2, respectively. PSBB and PSBT are thermally stable up to about 355°C in an N2 atmosphere and involve two-step degradation. DSC and DTA showed T g at about 125–127 and 138–142°C, respectively, for PSBB and PSBT in N2. PSBB and PSBT have comparable breakdown voltages and volume resistivity with some useful plastics whereas they have superior T g and thermal stability with retention of excellent solubility in common solvents over polysulfonates without a cardo group. Thus, the cardo (cyclo-hexyl) group has enhanced thermal and mechanical properties with excellent solubility and easy processing. 相似文献
158.
A proton-conducting nanocomposite gel polymer electrolyte (GPE) system, [35{(25 poly(methylmethacrylate) (PMMA) + 75 poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-HFP))?+?xSiO2}?+?65{1 M NH4SCN in ethylene carbonate (EC) + propylene carbonate (PC)}], where x?=?0, 1, 2, 4, 6, 8, 10, and 12, has been reported. The free standing films of the gel electrolyte are obtained by solution cast technique. Films exhibit an amorphous and porous structure as observed from X-ray diffractometry (XRD) and scanning electron microscopy (SEM) studies. Fourier transform infrared spectrophotometry (FTIR) studies indicate ion–filler–polymer interactions in the nanocomposite blend GPE. The room temperature ionic conductivity of the gel electrolyte has been measured with different silica concentrations. The maximum ionic conductivity at room temperature has been observed as 4.3?×?10?3?S?cm?1 with 2 wt.% of SiO2 dispersion. The temperature dependence of ionic conductivity shows a typical Vogel-Tamman-Fulcher (VTF) behavior. The electrochemical potential window of the nanocomposite GPE film has been observed between ?1.6 V and 1.6 V. The optimized composition of the gel electrolyte has been used to fabricate a proton battery with Zn/ZnSO4·7H2O anode and PbO2/V2O5 cathode. The open circuit voltage (OCV) of the battery has been obtained as 1.55 V. The highest energy density of the cell has been obtained as 6.11 Wh?kg?1 for low current drain. The battery shows rechargeability up to 3 cycles and thereafter, its discharge capacity fades away substantially. 相似文献
159.
Krishna Sai Gajula Naresh Mameda Srujana Kodumuri Durgaiah Chevella Rammurthy Banothu Vasu Amrutham 《合成通讯》2013,43(22):2866-2876
The synthesis of 2,3-dihydroquinazolin-4(1H)-ones by cyclocondensation of anthranilamide with ketones in aqueous media using Hβ zeolite is reported. The scope of the reaction was explored by various ketones such as aromatic, aliphatic and cyclic ketones. Based on the preliminary mechanistic results, a tentative mechanism for the formation of 2,3-dihydroquinazolin-4(1H)-ones using zeolite catalyst (Hβ) is predicted. The reusability study, large-scale experiment and water as solvent showed significant benefits of this catalytic protocol in comparing to earlier methods. 相似文献
160.
Mallikarjun Reddy Sura Vasu Govardhana Reddy Peddiahgari Rajendra Prasad Reddy Bhoomireddy Rama Krishna Vadde 《Journal of heterocyclic chemistry》2013,50(6):1395-1399
A new series of 2,4‐diaryl‐6‐methyl‐5‐nitropyrimidines ( 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i ) were synthesized in good yields by Suzuki–Miyaura coupling of 2,4‐dichloro‐6‐methyl‐5‐nitropyrimidine ( 3 ) with various aryl boronic esters ( 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i ) in the presence of 1,1′‐ bis(diphenylphosphino)ferrocene dichloropalladium(II) (Pd(dppf)2Cl2). Further, antibacterial and antioxidant properties were screened for the title compounds 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i . Most of the compounds possessed significant activity against Gram‐positive bacteria Staphylococcus aureus and Bacillus subtilis and Gram‐negative bacteria Escherichia coli and Klebsiella pneumoniae. The antioxidant activity of the title compounds showed significant antioxidant activity when compared with vitamin C. 相似文献