Three upper rim functionalized azoresorcin4arenes have been synthesized by coupling C-tetra(propyl)resorcin4arene with diazonium salts of the three regioisomers of aminobenzoic acid. The ...characterization of these azoresorcin4arenes was carried out by elemental analysis, FT-IR and 1H NMR. The densities of their solutions in dimethylsulfoxide (DMSO) were measured in the temperature range of (293.15–313.15) K and concentrations between (0.00483 and 0.02097) mol kg−1. From these experimental data, some thermodynamic parameters were derived for the understanding of the intermolecular interactions in solution and the influence of the position of the carboxylic group on the properties was analyzed.
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•Synthesis and characterization of diazoted tetra(propyl)resorcin4arenes.•Apparent partial molar volumes of their solutions in dimethylsulfoxide (DMSO).•Effect of temperature on the value of this property in the range (293.15–313.15) K.•Intermolecular and intramolecular hydrogen bonds presence in DMSO solutions.
For the first time, an adequate selective synthesis, circumventing the formation of 2‐hydroxy‐5H‐tetrazole, of 1‐hydroxy‐5H‐tetrazole (HTO), as well as the synthesis of ...bis(1‐hydroxytetrazol‐5‐yl)triazene (H3T) are reported. Several salts thereof were synthesized and characterized which resulted in the formation of new primary and secondary explosives containing the 1‐oxidotetrazolate unit. Molecular structures are characterized by single‐crystal X‐ray diffraction, 1H and 13C NMR, IR, and elemental analysis. Calculation of the detonation performance using the Explo5 code confirmed the energetic properties of 1‐hydroxy‐5H‐tetrazole. The detonation properties can be adjusted to the requirements for those of a secondary explosive by forming the hydroxylammonium (6) or hydrazinium (7) salts, or to meet the requirements of a primary explosive by forming the silver salt 4, which shows a fast DDT on contact with a flame. The sensitivities of all compounds towards external stimuli such as impact, friction, and electrostatic discharge were measured.
The reaction of 5‐amino‐1‐hydroxytetrazole (5‐ATO) with nitrous acid is strongly dependent on the equivalents of HNO2. By applying one equivalent and copper(0)/ethanol it is possible to perform a dediazonization, resulting in 1‐hydroxytetrazole – the highlight of this work. By applying half an equivalent of HNO2 it is possible to obtain the azo‐coupled product bis(1‐hydroxytetrazol‐5‐yl)triazene. Both compounds as well as salts thereof are fully characterized in this work.
In this paper, the synthesis of alkyl aryl ethers from electron poor phenols and amines, using 1,3-propanedinitrite, is described. Due to the mild conditions, functionalized primary, secondary, and ...tertiary alkyl groups were successfully introduced, denoting a highly tolerant process that allows for unprotected alcohols and acetals. The reaction is thought to proceed through the formation of a diazonium intermediate that undergoes subsequent S
N
2 or S
N
1 reactions.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Sulfadiazine, one of the sulfonamide group's active compounds, is widely used for therapeutic production against several diseases. Veterinary drug residues can have a significant impact on human ...health conditions. This study aimed to develop a prototype of rapid test devices (RTDs) for detecting sulfadiazine residues on chicken carcasses based on the color indication.
Seven samples of carcasses collected from traditional breeders in Surabaya-Indonesia were prepared and tested using RTDs. This sample represents the population considering that in the last report, the use of antibiotics was more than 40%, while the ability to monitor RTDs was estimated at 100. The standard color of purple by Hex code standard color or decimal code color was used to compare the positive samples. A light-emitting diode (LED) lamp was used to observe purple color. Analysis of sulfonamides resulting from RTDs was compared using a ultraviolet-visible spectrophotometer.
Sulfonamides contamination levels of 50% and 100% were detected at concentrations of 0.472 μg/mL and 0.642 μg/mL, respectively. Sulfonamides contamination that was <0.395 μg/mL did not appear purple.
The study's findings showed that RTDs can be used to detect sulfonamides residues at a limit of detection 0.5 mg/mL after a 45 min exposure to an LED operating at a wavelength of 980 nm (p < 0.05). The limitation of RTDs was not being able to monitor the presence of residues bound in fat samples. Rapid test devices can be developed for commonly monitoring devices due to the limited technology available in the market.
Condensation of 1
H
-1,2,4-triazolo-5-diazonium salts with 1,3-cyclohexanedione, accompanied by cascade processes of cyclization and oxidative aromatization, brought about the synthesis of novel ...derivatives of 1,2,4triazolo5,1-
c
1,2,4benzotriazin-6-ols.
The treatment of triaminoguanidinium chloride with two equivalents of sodium nitrite under acidic conditions, followed by the cyclization with stoichiometric amounts of either sodium hydroxide ...solution or solid sodium carbonate yielded 1-amino-5-azidotetrazole (1), 5-azido-1-diazidocarbamoyltetrazole (2), and 1-(aminoazidocarbamoyl)-5-azidotetrazole (3). The three novel compounds could be isolated by short-column liquid chromatography by using chloroform in reasonable yields. The mechanism of the formation as well as the decomposition pathway of the materials was investigated and a full characterization of all three compounds is presented. Compounds 1-3 have been characterized by means of Raman and IR as well as multinuclear NMR spectroscopy, mass spectrometry, and X-ray diffraction studies. Thermal stabilities have been evaluated by differential scanning calorimetry. Theoretical calculations have been performed to ensure the assignment of the vibrational modes obtained from Raman and IR measurements. The sensitivity values obtained from our measurements reflect the behavior of the compounds, which show an extremely high sensitivity toward mechanical as well as thermal stimuli.
Methods of synthesis of 3-nitroazolo5,1-
с
1,2,4triazin-4-amines, their conversion to 1,2,4triazolo5,1-
c
1,2,4triazine-3,4-diamines, and cyclization of one of the latter to 8
H
-imidazo4,5-
e
...1,2,4triazolo5,1-
c
1,2,4triazine have been developed with stable potassium salt of nitroacetonitrile.
A comparative analysis of physicochemical properties and reactivity of 3-aryl-1
H
-pyrazole-5-diazonium tetrafluoroborates and 5-aryl-3-diazo-3
H
-pyrazoles in azo coupling reactions is presented. It ...is shown that diazonium salts have higher reactivity compared to the respective 3-diazopyrazoles, which is in agreement with their physicochemical properties. Heterocyclization of the synthesized azo compounds provided 2-arylpyrazolo5,1-
c
1,2,4benzotriazines, which were screened for antitumor activity against human uterine endothelium cancer cells (HeLa cell line) and human skin fibroblasts using the MTT assay and flow cytometry. It was found that all of the tested compounds exhibited moderate to high cytotoxic activity. The best results were obtained with 6,8-dimethoxy-2-phenylpyrazolo-5,1-
c
1,2,4benzotriazine.
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