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151.
Tadashi Arai Katsuhiro Takahashi Akinori Kubo Shinsuke Nakahara Sadao Sato Kimie Aiba Chihiro Tamura 《Tetrahedron letters》1979,20(25):2355-2358
The structure of saframycin C(3) has been established by an X-ray crystallographic analysis; this result allows the assignment of structure to the closely related saframycin B(2) by 13C NMR spectroscopy. 相似文献
152.
Riko Ozao Hiroshi Ogura Moyuru Ochiai Sadao Tsutsumi 《Journal of Thermal Analysis and Calorimetry》1997,49(2):961-970
How a DSC result is influenced by the particle size distribution of a powder sample is shown, and a simple and optimal method to be included in a routine DSC analysis (e.g., purity determination) to improve the reliability of the analysis is proposed. In case of-Al2O3 powder, most reliable heat capacity data can be obtained by preparing a powder with a self-similar particle size distribution with a distribution constant of 0.7, and by compressing it under a pressure of 1.5 MPa for a duration of 5 min or longer.This work is partially supported by the Research Fund of North Shore College of SONY Institute. R.O. wishes to express her gratitude to the support. 相似文献
153.
Takashi Suzuki Ko-ichi Saeki Yoshinori Mayama Toshihiro Hirai Sadao Hayashi 《Reaction Kinetics and Catalysis Letters》1991,44(2):489-497
Hydrogenation of carbon dioxide was carried out over reduced Fe3O4 catalyst. Effect of reduction temperature of the catalyst, reaction temperature, space velocity, and component of feed gas were examined on the catalyst. From various experiments, the proper conditions for the hydrogenation of carbon dioxide are proposed. In addition, oxidation of the catalyst took place simultaneously during the hydrogenation of CO2.
Fe3O4. , , . , . CO2 .相似文献
154.
Keitaro Senga Kiyoko Fukami Hashime Kanazawa Sadao Nishigaki 《Journal of heterocyclic chemistry》1982,19(4):805-808
New synthetic routes to pyrido[3,2-d]pyrimidines starting with 5-amino-1,3,6-trimethyluracil (I) or 1,3,6-trimethyl-5-nitrouracil (X) are described. Thus, condensation of I with arylaldehydes gave 5-arylideneamino-1,3,6-trimethyluracils (IIa-h), which upon heating with dimethylformamide dimethylacetal afforded 6-aryl-1,3-dimethylpyrido[3,2-d]pyrimidine-2,4(1H,3H)-diones (Va-h) via 5-arylideneamino-1,3-dimethyl-6-(2-dimethylaminovinyl)uracils (IIIa-h). On the other hand, reaction of X with phenylacetaldehyde in the presence of base yielded Va and its 5-oxide (XI). 相似文献
155.
A method for the determination of seven alkylphenols and bisphenol A by stir bar sorptive extraction (SBSE) with in situ derivatization-thermal desorption (TD)-gas chromatography (GC)-mass spectrometry (MS) is described. SBSE was performed with in situ acetylation and without derivatization for comparison. For 4-tert-butylphenol and bisphenol A, in situ acetylation improved the responses in SBSE-TD-GC-MS. The method detection limits ranged from 0.1 to 3.2 ng/l. The recoveries of the analytes from a river water sample spiked with standards at 10 and 100 ng/l were 85.3-105.9% (R.S.D., 3.0-11.0%) and 88.3-105.8% (R.S.D., 1.6-8.3%), respectively. 相似文献
156.
Sadao Nishigaki Noriko Mizushima Hashime Kanazawa Misuzu Ichiba Keitaro Senga 《Journal of heterocyclic chemistry》1985,22(4):1029-1032
Synthesis and in vitro antibacterial activity of 7-(1′-alkylhydrazino)-1,8-naphthyridines related to nalidixic acid were investigated. Namely, treatment of 7-alkylamino-1-ethyl-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acids 1a-d with sodium nitrite in the presence of hydrochloric acid gave the 1-ethyl-1,4-dihydro-7-(N-nitrosoalkylamino)-4-oxo-1,8-naphthyridine-3-carboxylic acids 2a-d , which upon reacting with zinc dust in acetic acid gave the 7-(1′-alkylhydrazino)-1-ethyl-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylicacids 3a-d. The compound 3a was alternately obtained by the reaction of 7-chloro-1-ethyl-1,4-dihydro-4-oxo-1,8-naphth-yridine-3-carboxylic acid ( 4 ) with methylhydrazine. The reaction of 7-chloro-4-hydroxy-1,8-naphthyridine-3-carboxylic acid ( 5 ) with methylhydrazine gave the 4-hydroxy-7-(1′-methylhydrazino)-4-oxo-1,8-naphthyridine-3-carboxylic acid ( 6 ), which upon treatment with alkyl halides afforded the 1-alkyl-1,4-dihydro-7-(1′-methyl-hydrazino)-4-oxo-1,8-naphthyridines 3a and 3e-g. The reaction of the appropriate 3 with ketones gave the corresponding 7-(1′-methylalkylidenehydrazino)-1,8-naphthyridines 7a-c and 8a-b. Among the compounds prepared, certain 3 and 7 exhibited good activity against Gram-negative bacteria. 相似文献
157.
Three thieno-fused analogues of benzo[a]quinolizinium ( 1 ), thieno[3,2-a]- and thieno[2,3-a]quinolizinium 4 and 5 and thiazolo[2,3-a]isoquinolinium ( 6 ), were synthesized by photocyclization of 1-(2-thienylvinyl)pyridinium salts 9a and 9b and 3-styrylthiazolium salt 9c , respectively. The nitration of the compounds 4, 5 , and 6 occurred predominantly at positions 2, 3, and 7, respectively, while the nitro group was introduced into the 8- and 10-positions of 1 in the ratio of 68:32. The nmr and uv spectral properties and reduction potentials of 4–6 were also compared with those of the parent compound 1 . 相似文献
158.
Absolute configuration of (?)-solanapyrone A was confirmed by the application of CD exciton chirality method to the dibenzoate derivative. 相似文献
159.
Takashi Suzuki Toshihiro Hirai Sadao Hayashi 《Reaction Kinetics and Catalysis Letters》1991,43(2):293-299
CO and/or ethylene adsorbed on -Al2O3 was subjected to temperature programmed desorption (TPD). When temperature of the gas adsorbed specimens was linearly raised, two peaks were observed in desorption profile of both ethylene and that of CO. When an equimolecular misture of carbon monoxide and ethylene was adsorbed over the specimen, desorption temperature of CO(H) shifted to high temperature side of 87.2 °C, whereas that of ethylene (H) shifted to low temperature side of 33.0 °C. This behavior of desorption temperature might be attributed to a strong interaction in the two adsorbates induced by an electronic effect.
CO / -Al2O3 . , CO. CO(H) (87, 2°C), (H) (33°C). , .相似文献
160.
Vanessa Pezza Franzini Cecílio Sadao Fugivara Assis Vicente Benedetti Clóvis Augusto Ribeiro Eder Tadeu Gomes Cavalheiro José Anchieta Gomes Neto 《Electroanalysis》2007,19(17):1794-1798
A sensor based on graphite electrode modified with palladium‐platinum‐palladium film is proposed for phosphite determination by flow‐injection amperometry. The modified electrode was prepared by a sequential cathodic deposition of Pd, Pt and Pd on a graphite electrode from 0.5% m/v PdCl2+28% m/v NH4OH and 2% m/v H2PtCl6+10% v/v H2SO4 solutions. After suitable conditioning, the electrode showed catalytic activity for phosphite oxidation when 0.15 V was applied. The proposed system handles approximately 50 samples per hour (0.01–0.05 mol L?1 Na2HPO3; R2=0.9997), consuming ca. 70 μL of sample per determination. The limit of detection and amperometric sensibility were 5×10?4 mol L?1 and 1.5 mA L mol?1, respectively. The proposed method was applied to analysis of fertilizer samples without pre‐treatment. Results are in agreement with those obtained by spectrophotometry and titrimetry at 95% confidence level and good recoveries (96–109%) of spiked samples were found. Relative standard deviation (n= 12) of a 0.01 mol L?1 Na2HPO3 sample was 2%. The useful lifetime of modified electrode was around 220 determinations. For routine purposes it means that this electrode can be continuously used for 5 hours. 相似文献