scholarly journals SYNTHESIS AND REACTIVITY OF 4-NITRO-3-(TETRAZOL-5-YL) FURAZAN WITH N- AND O-NUCLEOPHILES

2017 ◽  
Vol 60 (5) ◽  
pp. 21
Author(s):  
Elena V. Stepanova ◽  
Andrei I. Stepanov
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
Carboxylic Acid ◽  
Total Yield ◽  
Cycloaddition Reaction ◽  
Chemical Properties ◽  
Amino Group ◽  
Nuclear Magnetic Resonance Spectra ◽  
13C Nuclear Magnetic Resonance ◽  
Partial Neutralization

A rational four-stages scheme for the synthesis of 4-nitro-3-(tetrazol-5-yl)furazane is proposed. The synthesis starts from the stage of 3-amino-4-(1,2,4-oxadiazol-3-yl)-furazan preparation by condensation of amidoxime of 4-aminofurazan-3-carboxylic acid with triethyl orthoformate, further reductive ring opening of 1,2,4-oxadiazole cycle. The action of hydrazine results in amidrazone of 4-aminofurazan-3-carboxylic acid formation. On the next step the diazotization of the resulting compound with sodium nitrite in acetic acid gives 3-amino-4-(tetrazol-5-yl)furazane. At last stage the titled 4-nitro-3-(tetrazol-5-yl)furazan was synthesized by oxidation of the amino group of 3-amino-4-(tetrazol-5-yl)furazan by a solution of 30% hydrogen peroxide in concentrated sulfuric acid with 85% yield. The increase in the oxidative activity of the H2O2/H2SO4 system by carrying out the oxidation stage at an elevated temperature made possible to substantially reduce the consumption of hydrogen peroxide and sulfuric acid. The desired 4-nitro-3-(tetrazol-5-yl)furazan was isolated by partial neutralization of the reaction mixture with sodium orthophosphate, followed by extraction with ethyl acetate. The total yield of 4-nitro-3-(tetrazol-5-yl)furazane in terms of the starting amidoxime of 4-aminofurazan-3-carboxylic acid was 42-48%. It was shown that the reaction of 4-nitro-3-(tetrazol-5-yl)furazan with a number of N- and O-nucleophilic agents (sodium azide, high-basic amines, hydrazine, sodium hydroxide, methanol in the presence of potassium carbonate) resulted in the substitution of the nitro group of the selected compound by a nucleophile and formation of corresponding 4-R-3-(tetrazol-5-yl)furazane derivatives (R = N3, substituted amino group, NHNH2, OH, OMe). Some chemical properties of thereby obtained compounds are considered. Thus [3 + 2] cycloaddition reaction of 4-azido-3-(tetrazol-5-yl)furazane (R = N3) with propargyl alcohol was used at the synthesis of 4- (4-hydroxy-methyl-1,2,3-triazol-1-yl)-3-(tetrazol-5-yl)furazane. The condensation of 3-hydrazino-4-(tetrazol-5-yl)furazane (R = NHNH2) with carbonyl compounds in the case of reaction with benzaldehyde leads to the corresponding hydrazone, with β-dicarbonyl compounds (malonaldehyde, acetylacetone) pyrazole derivatives were obtained. The synthesized compounds are characterized by 1H and 13C nuclear magnetic resonance spectra, by IR and mass spectroscopy. For citation:Stepanova E.V., Stepanov A.I. Obtaining and Reactivity of 4-nitro-3-(tetrazol-5-yl) furazan with N- and O-nucleophiles. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 5. P. 21-29

KARAKTERISASI SIFAT FISIKA DAN KIMIA CUKA KAYU DARI TANDAN KOSONG KELAPA SAWIT

2014 ◽  
Vol 6 (1) ◽  
pp. 35 ◽  
Author(s):  
Rizka Karima
Keyword(s):  
Specific Gravity ◽  
Physical Properties ◽  
Solid Waste ◽  
Ph Value ◽  
Total Yield ◽  
Chemical Properties ◽  
Phenol Content ◽  
Empty Fruit Bunches ◽  
Wood Vinegar ◽  
And Chemical Properties

There’s so many pal solid waste or palm empty fruit bunches, but the utilization is not maximized, this research its to optimized utilization of palm solid waste to be wood vinegar and want to know the composition physical properties and chemical properties of wood vinegar from palm empty fruit bunches. Total yield of wood vinegar from palm empty fruit bunches its 15,94 % and total yield of charcoal its 64,58 %. GCMS result showing chemical properties from wood vinegar of burning < 100oC its obtained 19 compound and burning >100 oC its obtained 6 compound. The result physichal properties testing from crued wood vinegar its obtained specific gravity 1,0005 and 1,0010, pH value are 3,233 and 3,186, TAT content are 9,36 % and 11,12 %, phenol content its 0,44 %. The result physical properties testing from wood vinegar which has decolorizatin by activated carbon its obtained specific gravity are 0,9987 and 0,999, pH value are 3,036 and 3,012, TAT content are 8,29 % and 9,27 % and phenol content its 0,01 %.Keywords: palm bunches, wood vinegar, liquid smoke

Decomposition of hydrogen peroxide on nickel-silver two-component catalyst

1984 ◽  
Vol 49 (10) ◽  
pp. 2222-2230 ◽  
Author(s):  
Viliam Múčka ◽  
Rostislav Silber
Keyword(s):  
Hydrogen Peroxide ◽  
Chemical Properties ◽  
Silver Ions ◽  
Surface Concentration ◽  
Chloride Ions ◽  
Nickel Silver ◽  
Silver Catalysts ◽  
Physico Chemical ◽  
Low Degree ◽  
Defective Crystal

The catalytic and physico-chemical properties of low-temperature nickel-silver catalysts with nickel oxide concentrations up to 43.8% (m/m) are examined via decomposition of hydrogen peroxide in aqueous solution. The mixed catalysts prepared at 250°C are composed of partly decomposed silver carbonate or oxide and nickel carbonate or hydroxide decomposed to a low degree only and exhibiting a very defective crystal structure. The activity of these catalysts is determined by the surface concentration of silver ions, which is affected by the nickel component present. The latter also contributes to the thermal stability of the catalytic centres of the silver component, viz. the Ag+ ions. The concentration of these ions varies with the temperature of the catalyst treatment, the activity varies qualitatively in the same manner, and the system approaches the Ag-NiO composition. The catalytic centres are very susceptible to poisoning by chloride ions. A previous exposition of the catalyst to a gamma dose of 10 kGy from a 60Co source has no measurable effect on the physico-chemical properties of the system.

scholarly journals Effective Recovery Process of Copper from Waste Printed Circuit Boards Utilizing Recycling of Leachate

JOM ◽  
2020 ◽  
Author(s):  
Joona Rajahalme ◽  
Siiri Perämäki ◽  
Roshan Budhathoki ◽  
Ari Väisänen
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
Printed Circuit Boards ◽  
Sulfuric Acid Concentration ◽  
Recovery Process ◽  
Copper Recovery ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Acid Consumption

AbstractThis study presents an optimized leaching and electrowinning process for the recovery of copper from waste printed circuit boards including studies of chemical consumption and recirculation of leachate. Optimization of leaching was performed using response surface methodology in diluted sulfuric acid and hydrogen peroxide media. Optimum leaching conditions for copper were found by using 3.6 mol L−1 sulfuric acid, 6 vol.% hydrogen peroxide, pulp density of 75 g L−1 with 186 min leaching time at 20°C resulting in complete leaching of copper followed by over 92% recovery and purity of 99.9% in the electrowinning. Study of chemical consumption showed total decomposition of hydrogen peroxide during leaching, while changes in sulfuric acid concentration were minor. During recirculation of the leachate with up to 5 cycles, copper recovery and product purity remained at high levels while acid consumption was reduced by 60%.

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