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31.
R. Krishna Mohan Rao Kallury Pramod V. Upadhyaya Tumbalam G. Surendra Nath Vankipuram R. Srinivasan 《Journal of mass spectrometry : JMS》1977,12(5):307-312
The mass spectra of eight 1,2,4-triazole derivaties have been recorded and found tao reveal extensive hydrogen and skeletal migrations. The structures of the fragments have been confirmed by deuterium labelling and exact mass measurement. The compounds revealed striking differences in their spectra depending on the nature of the substituents. 相似文献
32.
Krishna C. Joshi Vijai N. Pathak Raj Pal Singh 《Monatshefte für Chemie / Chemical Monthly》1980,111(6):1343-1350
Several new 2-(fluoroaryl)-3-dialkylaminomethylindoles, 3-acetyl-2-(fluoroaryl)-indoles, 2-(fluoroaryl)-3-indolylglyoxamides and corresponding tryptamines have been prepared as possible psychopharmacological agents. 2-(Fluoroaryl)-indoles have been synthesized by theFischer indole synthesis. 2-(Fluoroaryl)-indoles on treatment with oxalyl chloride and subsequent reaction with amines, gave 2-(fluoroaryl)-3-indolylglyoxamides. Some of these indolylglyoxamides were reducted with lithium aluminium hydride, to the corresponding tryptamines. 2-(Fluoroaryl)-indoles when subjected toMannich reaction afforded 3-dialkylaminomethyl-2-(fluoroaryl)-indoles. All these new compounds have been characterized by IR spectral studies.Possible Psychopharmacological Agents, Part XII, Part XI, J. Indian. Chem. Soc.57, 423 (1980). 相似文献
33.
Krishna K. Verma D. Sc. 《Mikrochimica acta》1980,74(3-4):211-217
Summary
-Amino acids are determined by reaction with perinaphthindan-2,3,4-trione hydrate to form dihydroxyperinaphthindenone which is titrated with chloramine-T in the presence of acidified bromide and methyl red. The thiol group of cysteine is blocked by cyano-ethylation before determination. Some amino acids can be directly titrated with chloramine-T in the presence of bromide and methyl red, e. g., cysteine (after cyanoethylation), methionine and lanthionine, or in the presence of iodide and starch, e. g., cysteine (after tetrathionate reaction) when concomitant amino acids do not interfere. These methods are used to analyze model mixtures of cysteine with serine, methionine with glycine and cysteine with methionine.
Analyse bestimmter Gemische von -Aminosäuren
Zusammenfassung -Aminosäuren werden mit Peri-Naphthindan-2,3,4-trion-hydrat umgesetzt, wobei sich Dihydroxyperinaphthindenon bildet, das mit Chloramin T in der Gegenwart von angesäuertem Bromid und Methylrot titriert wird. Die Thiolgruppe des Cysteins wird vor der Bestimmung durch Cyanoäthylierung blockiert. Manche Aminosäuren können unmittelbar mit Chloramin T in der Gegenwart von Bromid und Methylrot titriert werden, z. B. Cystein (nach Cyanoäthylierung), Methionin und Lanthionin, oder in Gegenwart von Jodid und Stärke Cystein (nach Umsetzung mit Tetrathionat), wenn die begleitende Aminosäure nicht stört. Diese Verfahren wurden benutzt, um Modellgemische von Cystein mit Serin, Methionin mit Glycin und Cystein mit Methionin zu analysieren.相似文献
34.
Efficient and simple colorimetric fluoride ion sensor based on receptors having urea and thiourea binding sites 总被引:6,自引:0,他引:6
[structure: see text] Novel colorimetric receptors for selective fluoride ion sensing containing anthraquinone as chromogenic signaling subunit and urea (N,N' '-(9,10-dihydro-9,10-dioxo-1,2-anthracenediyl)bis[N'-phenyl])/thiourea (N,N' '-(9,10-dihydro-9,10-dihydro-9,10-dioxo-1,2-antrhacenediyl)bis[N-phenyl]) binding sites have been reported. These receptors have shown no affinity for other halide ions (Cl-, Br-, and I- ions). Well-defined color change in the visible region of the spectrum was observed upon addition of fluoride ion in DMSO/CH3CN solution of the receptors 1 and 2. 相似文献
35.
A stereoselective synthesis of the pentaketide lactone (3R,4S,5S,9S)-3,5,9-trihydroxy-4-methylundecanoic acid δ-lactone has been achieved. 相似文献
36.
A new sphingolipid, (2S,3R,4E)-1,3-dihydroxy-2-[(nonadecanoyl) amino]-octadec-4-ene (1) along with ubiquitous batyl alcohol is isolated from the gorgonian, Junceella juncea Pallas (Gorgonaceae) of the Indian Ocean. The structure of 1 is determined on the basis of 1H- and 13C-NMR, COSY, FABMS, and GC-EIMS experiments. 相似文献
37.
Shaik Lateef SrinivasuluReddyKrishna Mohan Rudraraju Rameshraju SrinivasuluReddyJayarama Reddy 《Helvetica chimica acta》2006,89(6):1254-1257
Both aliphatic and aromatic amino sulfonamides such as mafenide ( 1a ) were synthesized in good yields (80–86%) by direct electrochemical hydrogenation of the corresponding nitriles in an undivided cell containing a Ni cathode, a Pt anode, and Raney Ni as catalyst (Table 1). The reaction can be performed without external supply of pressurized gas by in situ generation of H2. Slightly elevated temperatures (45°) and low current densities (10 mA/cm2) are favorable conditions for this type of electrochemical nitrile hydrogenation. Our synthetic protocol does not require high‐pressure equipment or chemical hazards, is environmentally very friendly, and more economical than traditional methods. The concentration of adsorbed H. radicals on the catalyst surface can be easily controlled by adjusting the electric potential, which may lead to improved product selectivity and, at the same time, reduces the risk of explosion and fire. 相似文献
38.
A general synthetic strategy for the rapid construction of poly(ether imine) dendrons and dendrimers with a nitrogen core, originating from 3-amino-propan-1-ol, is described. A new trifunctional monomer, namely, 3-[bis-(3-hydroxypropyl)amino]propan-1-ol, was used in a divergent synthesis of dendrimers up to the third generation. This method permitted installation of, either alcohol, amine, nitrile, ester or carboxylic acid groups at the peripheries the dendrimers. Cytotoxicity studies on water-soluble carboxylic acid terminated dendrimers were conducted and these studies revealed that poly(ether imine) dendrimers were non-toxic. These results illustrate that poly(ether imine) dendrimers are useful for biological studies. 相似文献
39.
P. V. Subba Rao G. S. R. Krishna Rao K. Ramakrishna P. S. N. Murty 《Reaction Kinetics and Catalysis Letters》1991,43(1):209-216
The micellar effet of sodium dodecyl sulfate (SDS) on the initial stages of the reaction between (1) Fe(II) and p-benzoquinone, and (2) Fe(III) and hydroquinone have been investigated. In the former case acceleration was observed, the rate-[surfactant] profile showing a maximum. SDS has an inhibitory effect on the latter reaction. Kinetic analysis has been carried out using Berezin's approach.
() 1) Fe(II) 2) Fe(III) . - . . , .相似文献
40.
E.p.r. spectra of [Cu(et2dtc)2], Na[Cu(asp/glut)(et2dtc)] and Na2[Cu(asp/glut)(et2dtc)2] in the polycrystalline state have
been recorded and discussed. The complexes display an antiferromagnetic exchange interaction, increasing in the order: Na2[Cu(asp/glut)(et2dtc)2]
< Na[Cu(asp/glut)(et2dtc)] < [Cu(et2dtc)2]
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献