نتایج جستجو برای: phosphorus pentoxide
تعداد نتایج: 42283 فیلتر نتایج به سال:
The paper will introduce a simple new method on the synthesis of both hafnium and zirconium nitrate precursors. The intermediate product, dinitrogen pentoxide produced from the water extraction from fume nitric acid via phosphorus pentoxide, was condensed by liquid nitrogen trap into a flask equipped with hafnium or zirconium tetrachloride. To give the high yield, the mixture of fume nitric aci...
An inductively coupled plasma atomic emission spectrometry (ICP-AES) method was developed for the determination of phosphorus in fertilizers. Total phosphorus, direct extraction available phosphorus (EDTA), and water-soluble phosphorus, reported as phosphorus pentoxide (P205), in 15 Magruder check fertilizers were measured by ICP-AES, and the results were compared with those obtained by the AOA...
silica supported phosphorus pentoxide (p2o5·sio2) is an efficient catalyst for synthesis of 1,3,5-substituted pyrazoles via the condensation of 1,3-diketones and hydrazines. simplicity of procedure, mild condition, being solvent-free, high yields, and easy workup are some advantages of this protocol.
Caps in α-Keggin-type polyoxometalates [PM2Nb12O40](9-) (M: Nb[double bond, length as m-dash]O or V[double bond, length as m-dash]O) can be removed in basic condition to produce uncapped [PNb12O40](15-). Transmetalation or capping occurs from the reaction of [PNb14O42](9-) or [PNb12O40](15-) with either Sb2O3 or V2O5 to form [PSb2Nb12O40](9-) or [PV2Nb12O42](9-), respectively.
An expeditious, one-pot method for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones using a mixture of phosphorus pentoxide-methanesulfonic acid (Eaton's reagent) at room temperature under solvent-free conditions is described. The salient features of this method include short reaction time, green aspects, high yields, and simple procedure.
A simple and efficient approach towards one step synthesis of 6-amino-5-cyano-4-phenyl-2-mercapto pyrimidine and its hydroxyl derivatives have been developed by three component condensation of aromatic aldehydes, malononitrile and thiourea/urea in presence of phosphorus pentoxide (Scheme 1).
In necrosis of the liver of the dog produced by haemotoxic immune sera, the increased excretion of uric acid, purin bases and inorganic phosphorus pentoxide is the result of the hydrolysis of nuclear material occurring during the autolysis of the necrotic tissue.
The condensation of aromatic aldehydes, dimedone, ethylacetoacetate and ammonium acetate promoted by was Phosphorus pentoxide supported on alumina carried out under solvent-free conditions to afford corresponding polyhydroquinolinederivatives. This method provides several advantages including highyields, low reaction times, easy work up and little catalyst loading.
Silica supported phosphorus pentoxide (P2O5·SiO2) is an efficient catalyst for synthesis of 1,3,5-substituted pyrazoles via the condensation of 1,3-diketones and hydrazines. Simplicity of procedure, mild condition, being solvent-free, high yields, and easy workup are some advantages of this protocol.
The isoniazid, after recrystallization from ethanol and drying over calcium chloride and then over phosphorus pentoxide, had m.p. 1700. Potentiometric titration with alkali (0.1 N-KOH), making use of the pK 10-8 (Albert, 1953) and ultraviolet spectrophotometry (at 262 m,u.), indicated a purity of 99.84%. This material was used to evaluate the published methods of iodometric titration. That cond...
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