Potassium Acetate Solution Bromide

Unsaturation value can be determined by the reaction of the akyl or propenyl end group with mercuric acetate ia a methanolic solution to give acetoxymercuric methoxy compounds and acetic acid (ASTM D4671-87). The amount of acetic acid released ia this equimolar reaction is determined by titration with standard alcohoHc potassium hydroxide. Sodium bromide is normally added to convert the iasoluble mercuric oxide (a titration iaterference) to mercuric bromide. The value is usually expressed as meg KOH/g polyol which can be converted to OH No. units usiag multiplication by 56.1 or to percentage of vinyl usiag multiplication by 2.7. 

The submitters report that -iodobenzyl alcohol can be prepared in a similar manner, and that it is unnecessary to isolate the acetate. A mixture of 148 g. of />-iodobenzyl bromide, 52 g. of potassium acetate, and 750 ml. of 95% ethanol is refluxed for 8 hours, cooled, and filtered from the salt. To the filtrate is added 33.6 g. of potassium hydroxide, and the solution is refluxed... 

Chau and Terry [146] reported the formation of penta-fluorobenzyl derivatives of ten herbicidal acids including 4-chloro-2-methyl-phenoxy acetic acid [145]. They found that 5h was an optimum reaction time at room temperature with pentafluorobenzyl bromide in the presence of potassium carbonate solution. Agemian and Chau [147] studied the residue analysis of 4-chloro-2-methyl phenoxy acetic acid and 4-chloro-2-methyl phenoxy butyric acid from water samples by making the pentafluorobenzyl derivatives. Bromination [148], nitrification [149] and esterification with halogenated alcohol [145] have also been used to study the residue analysis of 4-chloro-2-methyl phenoxy acetic acid and 4-chloro-2-methyl phenoxybutyric acid. Recently pentafluorobenzyl derivatives of phenols and carboxylic acids were prepared for detection by electron capture at very low levels [150, 151]. Pentafluorobenzyl bromide has also been used for the analytical determination of organophosphorus pesticides [152],... 

Refluxing a solution of 2-formylphenyl tellurium bromide, hydroxylaminc hydrochloride, and potassium acetate in absolute ethanol produced the corresponding oxime2. 

For the determination of phenoxy groups in phenoxyphenylsilanes, bomb fusion with potassium hydroxide is carried out and an aliquot of an aqueous solution of the melt is analysed for phenoxide by titration with potassium bromide-potassium bromate solution. Phenylphenoxy groups in phenyl(phenylphenoxy)silanes are similarly determined, but the melt is dissolved in anhydrous acetic acid138. 

Potassium nitrite solution iodine is liberated when this reagent is added to an iodide solution acidified with dilute acetic or sulphuric acid (difference from bromide and chloride). The iodine may be identified by colouring starch paste blue, or chloroform violet. 

The reaction progress was followed by titrating the unreacted carboxyl groups in samples removed from the reaction mixture at different times of reaction, with a standard methanolic potassium hydroxide solution. The oxirane groups were also titrated in some of the samples, using the hydrogen bromide in glacial acetic acid titration technique (21). 

Attempts to carry out a similar sequence of reactions on j8-bromo-cyanolycopodine LIV were thwarted for a long time by the tendency of this compound to eliminate hydrogen bromide. Treatment with potassium acetate in methanol, amines, and other bases always led to the same nonketonic, very unreactive compound, which was eventually shown to be the enol ether LV 41). With silver acetate in benzene, however, LIV yielded a mixture of LV and an acetoxy compound in an approximate ratio of 3 1. Treatment of the acetate in the same sequence of reactions used in the a-series gave the carboxylic acid LVI. When LVI was treated with sodium borohydride and the acidified reaction mixture extracted into chloroform a neutral compound was isolated. In its IR-spectrum it had 1743 cm in Nujol which shifted to 1761 cm i in chloroform solution, but there was no absorption in the hydroxyl region. The IR-speetrum and the elemental analysis were in agreement with the lactone structure LVII. When this work was carried out, however, the IR-evidence alone was not sufficient to differentiate between a y- and a S-lactone ([Pg.331]

Preparation by reaction of potassium bromate and bromide on 2,4-diethyl-6-hydroxyacetophenone in solution of acetic acid-carbon tetrachloride mixture (quantitative yield) [2965],... 

Reagents To 40 ml of a solution containing 4 g of KCN are added 5 ml of acetic acid and 40 ml of a solution containing 3 g of potassium bromate and 4 g of potassium bromide. Concentrated sulfuric acid (4 ml) is then added dropwise and the solution is diluted with water to make its volume 100 ml. 10% sodium acetate solution acetone 0.05% solution of benzidine in ethanol containing 2% of acetic acid. 

The reaction was carried out in reaction block. In a 40-mL vial with a septum, stir bar, and screw, the appropriate aryl bromide (3 mmol) and the boronic acid (3.6 mmol) were dissolved in a mixture of 20 mL of dioxane and 5 mL of 2 M potassium carbonate solution. Nitrogen was bubbled for 30 min through the reaction solution. Then, in a countercurrent of nitrogen, tetrakis-triphenylphosphine palladium (5 mol%) was added, the needle was removed and the vial heated for 40 h at 120 °C. The reaction mixture was poured into ethyl acetate (50 mL), filtered through silica gel with 100 mL of 1 M sodium hydroxide wash. 

Table 2 Hsts examples of compounds with taste and their associated sensory quaUties. Sour taste is primarily produced by the presence of hydrogen ion slightly modified by the types of anions present in the solution, eg, acetic acid is more sour than citric acid at the same pH or molar concentration (43). Saltiness is due to the salts of alkaU metals, the most common of which is sodium chloride. However, salts such as cesium chloride and potassium iodide are bitter potassium bromide has a mixed taste, ie, salty and bitter (44). Thus saltiness, like sourness, is modified by the presence of different anions but is a direct result of a small number of cations.

In a 25% aqueous solution of potassium bromide. The resultant solution is acidified with a 20% solution of sodium bisulfite, centrifuged, washed with water and then dried under vacuum. The product Is then recrystallized in acetic acid and 13.6 g of 2-(4 -hydroxy-3, 5 -di-bromo-benzoyl)-3-athyl coumarone obtained. MP 151°C. 

Senti and Witnauer206 have reported studies on the fiber diagrams from various alkali-amyloses. Specimens were obtained by deacetylating clamped specimens of amylose acetate with the appropriate alkali. The positions of the alkali ions and the lateral packing of the amylose chains were determined with the aid of Patterson projections. In the A - and B -modifica-tions, the fiber period was 22.6 A. (extension of 6 D-glucose units), whilst in the V -modification it was 8.0 A. These authors have also studied in detail the addition compounds of amylose and inorganic salts with special reference to the structure of the potassium bromide-amylose compound.206 Oriented alkali fibers were treated with the appropriate salt solution. Stoichiometric compounds were formed. The x-ray patterns from these showed that the addition compounds with potassium salts crystallized in... 

Preparation of 4-12-cvclohexenvloxv )-stvrene. A stirred mixture of 34.36g (0.096 mole) methyltriphenylphosphonium bromide and 10.75g (0.096 mole) potassium t-butoxide in 200ml dry THF is treated drop-wise with a solution of 16.16g (0.080 mole) of 4-(2-cyclohexenyl)-benzaldehyde in 30ml THF under inert atmosphere. Once the addition of aldehyde was completed, the mixture was stirred at room temperature for another 2 hours. Ether and water were then added to the reaction mixture until clearly separated phases were obtained with no solid residue. The organic layer was separated and washed three times with water, dried over magnesium sulfate and evaporated. The resulting semi-solid was triturated in 10% ethyl acetate-hexane mixture to remove most of the triphenylphosphine and the evaporated extract was purified by preparative HPLC using hexane as eluent. This afforded 9.35g (58%) of the pure monomer, which was fully characterized by H and C-NMR as well as mass spectrometry. 

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