Potassium persulfate-Silver nitrate

Potassium persulfate-Silver nitrate [1, 954, before Potassium thiocyanate]. This combination is about as satisfactory as Attenburrow manganese dioxide for the oxidation of 5-hydroxyuracil to uracil-5-aldehyde.1... 

Ammonium persulfate-Silver nitrate (see Potassium persuifate-Silver nitrate, 1,954 2, 348-349). 

Sahcylaldehyde is readily oxidized, however, to sahcyhc acid by reaction with solutions of potassium permanganate, or aqueous silver oxide suspension. 4-Hydroxybenzaldehyde can be oxidized to 4-hydroxybenzoic acid with aqueous silver nitrate (44). Organic peracids, in basic organic solvents, can also be used for these transformations into benzoic acids (45). Another type of oxidation is the reaction of sahcylaldehyde with alkaline potassium persulfate, which yields 2,5-dihydroxybenzaldehyde (46). 

Silver(ll) oxide is prepared by reacting silver nitrate with potassium persulfate in the presence of a base. 

Xanthydrol is oxidized by potassium persulfate (56MI22400), whilst xanthydryl chloride yields xanthone on reaction with silver nitrate (59JCS458). 

A solution of 1.25 of silver nitrate in 25ml of distilled water is mixed with 10ml of pure pyridine, and the mixture is stirred into 15 of fresh potassium persulfate dissolved in 500ml of cold distilled water. The liquid immediately assumes an orange color the product soon begins to precipitate, and this is complete in about 30 minutes. After it is filtered, the orange material is washed with two 10ml portions of ice-cold water and then dried for an hour or two in vacuo over solid alkali. 

Preparation.1 The reagent is prepared by the reaction of picolinic acid (pyridine-2-carboxylic acid) with silver nitrate and potassium persulfate. The material is stable on storage in the dark at room temperature for several months. 

In the early oxidation nitration preparation of DNPOH, the yield is relatively low (59-63 %), the product needs further purification, there is formaldehyde condensation reaction and other serious problems. Jeong et al. [63] modified the oxidation nitration process to optimize the oxidation nitration conditions of silver nitrate, in which aqueous formaldehyde solution (mass fraction of 35 %) was used for hy-droxymethylation and its reaction conditions were optimized, and a yellow solid DNPOH was obtained after extraction with methylene chloride and distillation. The average yield of DNPOH was more than 90 % and the mass fraction was more than 97 %. Based on these results, Grakauskas et al. [40-42, 65] used potassium ferri-cyanide as catalyst and potassium persulfate as oxidant to synthesize DNPOH. In this method, with potassium(sodium) ferricyanide and over potassium(sodium) persulfate, nitrite substitution reaction of nitroethane with sodium nitrite occurred, and then further reacted with formaldehyde under basic conditions, and finally DNPOH was extracted out with ethyl acetate under acidic conditions. Product was obtained through potassium distillation. The reaction mechanism is ... 

In the improvement of DNPDOH (2,2-dinitro-1,3-propanediol) [66], used sodium nitrite was reduced from 4 times to the equal amount, the amounts of sodium persulfate and potassium ferricyanide were adjusted, which reduced the impact of carbon emission pollution on the environment, and the cost of synthesis was reduced. The synthesis yield was 68 % after improvement, and lower than the production cost is much lower than that of silver nitration method. Major improvement in electrochemical synthesis of DNPOH is that In the first step, sodium hydroxide solution was added to an aqueous solution of 2-nitropropanol after 45 min of stirring at room temperature, lithium perchlorate solution and sodium nitrite solution were added to prepare the deprotonated 2-nitropropanol solution in the second step, deprotonated 2-nitro-propanol solution is added into the working electrode chamber and the reference electrode chamber of the electrolytic cell, and electrolytic reaction is continued for about 1 h under nitrogen for 20 min. Finally DNPOH will be obtained with a yield of about 40 %. The reaction mechanism is ... 

A new approach for direct arylation of pyridine W-oxides with arylboronic acids through C-H functionalization has been developed (Scheme 45) [99]. This reaction can be performed at room temperature using catalytic silver (I) nitrate in the presence of potassium persulfate, thus giving 2-aryl derivatives of pyridine W-oxides. 

Potassium metabisulfite Potassium persulfate Propyl alcohol Pyrocatechol Silver iodide Silver nitrate Silver potassium cyanide Sodium alum Sodium arsenite Sodium benzoate... 

Benzoyliminopyridinium ylide couples with phenylboronic acids at C-2 and C-4 (Scheme 37).This direct C-H arylation occurs at room temperature with an inexpensive catalyst silver nitrate with potassium persulfate. An excess of the phenylboronic acid was necessary for a high conversion additionally, using phenylboronic acid pinacol ester decreased the yield. Coupling a quinoline ylide also resulted in a mixture of C-2 and C-4 arylation, with a slight preference for the C-2. Alkylated pyridine ylides also coupled with a mixture of C-2 and C-4 arylations when possible (14SL1413). 

Procedure. A drop of the test solution is mixed on a spot plate with a drop of a saturated solution of potassium persulfate and a drop of a 2 % silver nitrate solution, and allowed to stand for 2 or 3 minutes. On adding a drop of 1 % alcoholic diphenylcarbazide solution, a violet to red color is formed this fades on long standing. 

Keywords Electron-deficient heteroarenes, triazenes, silver nitrate, potassium persulfate, trifluoroacetic acid, dichloromethane-water (3 5), room temperature, open-flask C-H functionalization, C-arylation, substituted heteroarenes... 

To a stirred solution of heteroarene (2 0.4 mmol) in dichloromethane (1.5 mL) at ambient temperature under open-flask was added TFA (0.32 mL) and triazene (1 0.6 mmol), the mixture was then stirred vigorously for 5 min. Then water (1.5 mL) and silver nitrate solution (20 mol % in 1.0 mL water) and potassium persulfate (0.32 g) was added successively, and the stirring was continued up to 24 h (TLC monitored). Upon completion of the reaction, 2N NaOH was added to quench excess TFA, extracted with dichlorometahne (5 x 20 mL), and dried over anhydrous sodium sulfate. Solvent was evaporated under reduced pressure and the crude residue was purified by silica gel flash chromatography (10% MeOH in CH2CI2) to furnish pure substituted het-eroaren 3, characterized by means of spectral studies. 

Heteroaryl phosphonates are common motifs in biological compounds and have stimulated the development of transition metal-catalyzed methodologies for C-P bond formation [68]. Phosphonated thiophenes 43 are accessible via silver-catalyzed dehydrogenative cross-coupling of thiophene 1 with dialkyl phosphites 42 (Scheme 19) [69]. The reaction is performed in aqueous dichloromethane, proceeds regioselectively at the a-position, and utilizes silver(l) nitrate as catalyst and the oxidant potassium persulfate. 

Upon cooling, sulfuric acid and diphenylcarbazide were added which produced a violet-red color (Cazeneuve reaction (17)), the intensity of which was measured in a Pulfrioh photometer with an S-53 filter. Potassium persulfate and silver nitrate were unsatisfactory as oxidizing agents. Marenzi and Cardini (60) used this method for the determination of choline in the lecithin and sphingomyelin fractions of blood with apparent good results. 

Other C-H arylation conditions use p-tolyl boronic acid, silver(I) nitrate, potassium persulfate, and trifluoroacetic acid (eq 12). In this case, the regioselectivity is controlled by the inherent reactivity of the substrate and the transformation is reminiscent of the Minisci conditions. Here, it is suggested that pyridazine reacts with a reactive p-tolyl radical generated in situ fromp-tolyl boronic acid. 

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