Synthesis of some 2-aryl-6-amino-2,3-dihydro-1,2,4-benzotriazin-3-ones

1980 ◽  
Vol 45 (5) ◽  
pp. 1379-1387 ◽  
Author(s):  
Jan Slouka ◽  
Vojtěch Bekárek
Keyword(s):  
Ir Spectroscopy ◽  
Acid Medium ◽  
Ethyl Chloroformate ◽  
High Yields ◽  
Simultaneous Splitting

Acylation of 2,4-diaminobenzene and its derivatives Ia-Ih with ethyl chloroformate gives high yields of the corresponding 2,4-bis(ethoxycarbonylamino)azobenzenes IIa-IIh which, on boiling in acid medium, are cyclized with simultaneous splitting off of the second ethoxycarbonyl group to give the mesomeric 6-amino-2-aryl-3-oxo-2,3-dihydro-1,2,4-benzotriazinium cations IIIa-IIIh; the latter have been transformed into the free bases IVa-IVh or their tautomers Va-Vh. Constitution of the prepared compounds has been studied by IR spectroscopy. Influence of medium on valence vibrations of the carbamate NH groups in the compounds II has also been studied.

Synthesis and cyclization of some N-oxides of 2-pyridylhydrazones of mesoxalic acid derivatives

1988 ◽  
Vol 53 (3) ◽  
pp. 626-632 ◽  
Author(s):  
Jan Slouka ◽  
Vojtěch Bekárek
Keyword(s):  
Ir Spectroscopy ◽  
Acid Medium ◽  
Tautomeric Forms

Coupling of diazotized 2-aminopyridine-1-oxide with ethyl cyanoacetylcarbamate, cyanoacetamide, malononitrile, and 2-benzimidazolylacetonitrile in an acid medium afforded N-oxides of the corresponding 2-pyridylhydrazones Ia-Id, which also exist in the N-hydroxyazine tautomeric forms IIa-IId as confirmed by IR spectroscopy. Hydrazone Ia was thermally cyclized to give 2-(pyridine-1-oxide-2-yl)-3,5-dioxo-2,3,4,5-tetrahydro-1,2,4-triazine-6-carbonitrile (IIIa) which was converted into the corresponding thioamide IIIb, acid IIIc, and amidoxime IIId.

Dimeric Ecdysteroid Analogues and Their Interaction with the Drosophila Ecdysteroid Receptor

2006 ◽  
Vol 71 (8) ◽  
pp. 1229-1238 ◽  
Author(s):  
Juraj Harmatha ◽  
Miloš Buděšínský ◽  
Karel Vokáč ◽  
Laurence Dinan ◽  
René Lafont
Keyword(s):  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Oxygen Atmosphere ◽  
Inert Gas ◽  
Photochemical Transformation ◽  
Dimer Formation ◽  
Ecdysteroid Receptor ◽  
Gas Atmosphere ◽  
Agonistic Activity ◽  
High Yields

Three structurally related specific ecdysteroid derivatives, 7,7'-dimers of 14-deoxy-8(14)-ene transformed 20-hydroxyecdysone, ponasterone A and ajugasterone C, were obtained by photochemical transformation. The structures of the dimeric ecdysteroids were identified mainly by NMR spectroscopy supported by MS and IR spectroscopy. Yields of the dimerisation products were dependent on the reactant concentrations and photoreaction conditions. Inert gas atmosphere supported high yields, whereas oxygen atmosphere fully prevented the dimer formation. All the three dimers retained a rather high agonistic activity at the ecdysteroid receptor in the Drosophila BII bioassay when compared with the relevant original ecdysteroids.

A new 2-oxy-N,N-dioctylacetamide grafted resin for the separation of trivalent actinides from nitric acid medium

2015 ◽  
Vol 103 (2) ◽  
Author(s):  
B. Robert Selvan ◽  
T. Prathibha ◽  
K. A. Venkatesan ◽  
M. P. Antony ◽  
P. R. Vasudeva Rao
Keyword(s):  
Nitric Acid ◽  
Ir Spectroscopy ◽  
Acid Medium ◽  
Elemental Analysis ◽  
Sodium Nitrate ◽  
Nitric Acid Medium ◽  
Extraction Behavior ◽  
Trivalent Actinides ◽  
Merrifield Resin ◽  
First Time

AbstractA novel 2-oxy-N,N-dioctylacetamide anchored on Merrifield resin was synthesized and characterized by elemental analysis, TG-DTA and IR spectroscopy, for the first time. The extraction behavior of Am(III) and Eu(III) from nitric acid medium in the dioctylacetamide anchored resin (R-DOA) was studied as a function of various parameters such as duration of equilibration, concentration of nitric acid and sodium nitrate etc. The distribution coefficient (

Catalysis and reaction mechanisms of N-formylation of amines using Fe(III)-exchanged sepiolite

2014 ◽  
Vol 68 (5) ◽  
Author(s):  
Bilge Eren ◽  
Reyhan Aydin ◽  
Erdal Eren
Keyword(s):  
Ir Spectroscopy ◽  
Formic Acid ◽  
Thermal Desorption ◽  
Lewis Acid ◽  
Reaction Mechanisms ◽  
Adsorption Mechanism ◽  
Catalytic Properties ◽  
Temperature Range ◽  
High Yields

AbstractThis study presents a rapid, economical and “green” N-formylation of anilines with formic acid (FA) using Fe(III)-exchanged sepiolite (IES) as a catalyst. The IES exhibited excellent catalytic properties and the reactions were complete within 20.90 min to afford products with high yields. The adsorption mechanism of FA on the IES sample was studied by infrared (IR) spectroscopy at a temperature range of 120–400°C. The thermal desorption of pyridine was detected by the IR technique to estimate the acidity of IES. Lewis acid-bound pyridine bands at 1618–1631 cm-1 and 1443–1445 cm-1 were observed even after the IES sample was heated above 400°C.

IR SPECTROSCOPY WITH SURFACE ELECTROMAGNETIC WAVES

1984 ◽  
Vol 45 (C5) ◽  
pp. C5-167-C5-178
Author(s):  
A. J. Sievers ◽  
Z. Schlesinger ◽  
Y. J. Chabal
Keyword(s):  
Ir Spectroscopy ◽  
Electromagnetic Waves ◽  
Surface Electromagnetic Waves

A Simple Method for Preparing Fibrinogen

1966 ◽  
Vol 16 (01/02) ◽  
pp. 198-206 ◽  
Author(s):  
W Straughn ◽  
R. H Wagner
Keyword(s):  
Barium Sulfate ◽  
Caproic Acid ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Human Fibrinogen ◽  
Simple Method ◽  
High Yields ◽  
Marked Stability

SummaryA simple new procedure is reported for the isolation of canine, bovine, porcine, and human fibrinogen. Two molar β-alanine is used to precipitate fibrinogen from barium sulfate adsorbed plasma. The procedure is characterized by dependability and high yields. The material is 95% to 98% clottable protein but still contains impurities such as plasminogen and fibrin-stabilizing factor. Plasminogen may be removed by adsorption with charcoal. The fibrinogen preparations exhibit marked stability to freezing, lyophilization, and dialysis. Epsilon-amino-n-caproic acid and gamma-aminobutyric acid which were also studied have the property of precipitating proteins from plasma but lack the specificity for fibrinogen found with β-alanine.

A Novel Method for the Rapid Purification of Human and Rat Fibrin(OGEN) Degradation Products in High Yields

1979 ◽  
Author(s):  
W. Nieuwenhuizen ◽  
I. A. M. van Ruijven-Vermeer ◽  
F. Haverkate ◽  
G. Timan
Keyword(s):  
Degradation Products ◽  
Complete Separation ◽  
Purification Method ◽  
Amino Terminal ◽  
Novel Method ◽  
Rapid Purification ◽  
The One ◽  
High Yields ◽  
Size Heterogeneity ◽  
D Dimer

A novel method will be described for the preparation and purification of fibrin(ogen) degradation products in high yields. The high yields are due to two factors. on the one hand an improved preparation method in which the size heterogeneity of the degradation products D is strongly reduced by plasmin digestion at well-controlled calcium concentrations. At calcium concentrations of 2mM exclusively D fragments, M.W.= 93-000 (Dcate) were formed; in the presence of 1OmM EGTA only fragments M.W.= 80.000 (D EGTA) were formed as described. on the other hand a new purification method, which includes Sephadex G-200 filtration to purify the D:E complexes and separation of the D and E fragments by a 16 hrs. preparative isoelectric focussing. The latter step gives a complete separation of D (fragments) (pH = 6.5) and E fragments (at pH = 4.5) without any overlap, thus allowing a nearly 100% recovery in this step. The overall recoveries are around 75% of the theoretical values. These recoveries are superior to those of existing procedures. Moreover the conditions of this purification procedure are very mild and probably do not affect the native configuration of the products. Amino-terminal amino acids of human Dcate, D EGTA and D-dimer are identical i.e. val, asx and ser. in the ratgly, asx and ser were found. E 1% for rat Dcate=17-8 for rat D EGTA=16.2 and for rat D- dimer=l8.3. for the corresponding human fragments, these values were all 20.0 ± 0.2.

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