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41.
Gary M. Coppola 《Journal of heterocyclic chemistry》1979,16(5):897-901
Novel fused tricyclic phosphorus heterocycles 9 and 11 and the tetracycle 15 were synthesized by cyclization of 1-haloalkyl (or 3-haloalkyl)-2,3-dihydro-1,3,2-benzodiazaphosphorin-4(1H)one 2-oxides with sodium hydride. Some spectral data of the products are also discussed. 相似文献
42.
43.
Moetaz I. Attalla Geoffrey R. Burnett Lindsay A. Summers 《Journal of heterocyclic chemistry》1985,22(2):319-320
3-(3′-Pyridinyloxymethyl)pyridine is prepared by reaction of 3-hydroxymethylpyridine with 3-bromopyridine and converted to the 1,1′-dimethyl and 1,1′-diethyl diquaternary salts with alkyl iodides. The salts are reduced polarographically at a potential (Eo) of about - 1.02 to - 1.10 V in the pH range of 5.5-8.5. 相似文献
44.
Pulsed IR radiation from a CO2 TEA laser has been shown to cause dehydrohalogenation of CF3CH3, CF2ClCH3 and C2H5Cl under collisionless conditions. IR emission has been observed and is attributed to HF2 and CF2CH22 from CF3CH3, and to HF2 and HCl2 from CF2ClCH3. 相似文献
45.
In an extension of recently reported syntheses of the I-azaphenoxathiin nucleus as well as several 7-substituted analogs, the synthesis of several 9-substituted members of this series is now reported. In addition, the first 13C-nmr spectral evidence of an interaction between a sulfur atom and the oxygen of an ortho-nilro group which has been previously observed only in X-ray erystallographic studies is also described. The possible consequences of this interaction on the reaction pathway leading to the cyclization of the 9-substituted J-azaphenoxathiin nucleus is also presented. 相似文献
46.
Summary A sensitive method has been developed for analysis of trace amounts of arsenic in biological materials using the heteropoly blue method. The method employs a closed apparatus and a nitrogen atmosphere, and allows the detection of arsenic in ppm concentration using samples of 100 mg.
Presented at the 6th Annual Northeast Regional Meeting of the American Chemical Society, Burlington, Vermont, August 19, 1974. 相似文献
Zusammenfassung Eine empfindliche Methode zur Bestimmung von Arsenspuren in biologischem Material im Wege der Molybdänblaumethode wurde ausgearbeitet. Man arbeitet dabei in einer geschlossenen Apparatur in Stickstoffatmosphäre und kann so in 100-mg-Proben Arsenkonzentrationen in der Größenordnung von ppm bestimmen.
Presented at the 6th Annual Northeast Regional Meeting of the American Chemical Society, Burlington, Vermont, August 19, 1974. 相似文献
47.
Burlage Robert S. Palumbo Anthony V. Heitzer Armin Sayler Gary 《Applied biochemistry and biotechnology》1994,45(1):731-740
Applied Biochemistry and Biotechnology - Reporter strains of bacteria were tested using soil samples from several sites near a leaking fuel oil storage facility. The reporter bacteria utilized the... 相似文献
48.
Gary L. Anderson 《Journal of heterocyclic chemistry》1985,22(5):1469-1470
The reaction of diethyl ethoxymethylenemalonate ( 1 ) and 6-amino-1,3-dimethyluracil ( 2 ) was determined to be regioselective. Under acidic conditions the product was the previously isolated 7-oxopyrido[2,3-d]pyrimidine ( 3 ), while in the presence of one equivalent of base followed by thermal cyclization, the isomeric 5-oxopyrido[2,3-d]pyrimidine ( 5 ) is formed. 相似文献
49.
William H. McCarroll Cynthia Darling Gary Jakubicki 《Journal of solid state chemistry》1983,48(2):189-195
Fused salt electrolysis has been used to prepare a number of reduced oxides of molybdenum with lanthanum, neodymium, and yttrium in single crystal or oriented polycrystalline form. The average valence of molybdenum in the various compounds ranged from 5.67 to 3.50. Previously unreported compounds include La5Mo4O16 (triclinica = 5.64 Å,b = 20.7 0Å,c = 5.64 Å, α = 86.55°, β = 90.0°, γ = 93.45°); La2Mo2O7 (orthorhombic,a = 12.19 Å,b = 6.05 Å,c = 3.87 Å); LaMo2O5 (hexagonal,a = 8.378 Å,c = 19.26 Å). In addition, single crystal specimens have been prepared of Y2MoO5,Ln5Mo3O16(Ln =La, Nd) and metal atom cluster compounds of theA2Mo3O8 type (A = Mg, Co, Ni, Zn). 相似文献
50.
The separation of a selected group of naturally occurring, heterocyclic nitrosoamino acids was achieved by capillary zone electrophoresis and the resolution of the syn and anti conformers improved as the temperature was lowered to 5 °C. The double peaks observed for each nitrosoamino acid are probably caused by the slow kinetics of conformational isomerism. The experimental setup consisted of a P/ACE 5510 electrophoresis system, a 57 cm polyacrylamidecoated capillary, and a 10 mM phosphate buffer, pH 7.2, containing 2 mM of 3-(N-N-dimethylmyristylammonio)propanesulfonate (DMMAPS) and 0.1% Tween 20. Our study shows that (a) the lower the temperature, the greater the resolution and the longer the migration times; and (b) different nitrosoamino acid conformers were resolved at different temperatures because of differences in the rate of isomerization. For example, the conformers of N-nitrosothiazolidine-4-carboxylic acid were partially resolved at 30 °C while those of N-nitrosoproline were well resolved at the same temperature. 相似文献