Potassium bicarbonate, reduction

The reduction is carried out much as described in Procedure 2. Ammonia (950 ml) is distilled into a 5-liter reaction flask and 950 ml of /-amyl alcohol and a solution of the ketal in 950 ml of methylcyclohexane are added with good stirring. Sodium (57 g, 2.5 g-atoms) is added in portions. The reaction mixture becomes blue within 30-45 min after the sodium is added and the metal is consumed within about 3 hr after the blue color appears. After the mixture becomes colorless, 200 ml of ethanol is added and the ammonia is allowed to boil off through a mercury trap. Then 500 ml of water and 500 ml 0% potassium bicarbonate solution are added and the organic layer is separated. The organic layer is washed once with 10 % potassium bicarbonate... 

The crude ketal from the Birch reduction is dissolved in a mixture of 700 ml ethyl acetate, 1260 ml absolute ethanol and 31.5 ml water. To this solution is added 198 ml of 0.01 Mp-toluenesulfonic acid in absolute ethanol. (Methanol cannot be substituted for the ethanol nor can denatured ethanol containing methanol be used. In the presence of methanol, the diethyl ketal forms the mixed methyl ethyl ketal at C-17 and this mixed ketal hydrolyzes at a much slower rate than does the diethyl ketal.) The mixture is stirred at room temperature under nitrogen for 10 min and 56 ml of 10% potassium bicarbonate solution is added to neutralize the toluenesulfonic acid. The organic solvents are removed in a rotary vacuum evaporator and water is added as the organic solvents distill. When all of the organic solvents have been distilled, the granular precipitate of 1,4-dihydroestrone 3- methyl ether is collected on a filter and washed well with cold water. The solid is sucked dry and is dissolved in 800 ml of methyl ethyl ketone. To this solution is added 1600 ml of 1 1 methanol-water mixture and the resulting mixture is cooled in an ice bath for 1 hr. The solid is collected, rinsed with cold methanol-water (1 1), air-dried, and finally dried in a vacuum oven at 60° yield, 71.5 g (81 % based on estrone methyl ether actually carried into the Birch reduction as the ketal) mp 139-141°, reported mp 141-141.5°. The material has an enol ether assay of 99%, a residual aromatics content of 0.6% and a 19-norandrost-5(10)-ene-3,17-dione content of 0.5% (from hydrolysis of the 3-enol ether). It contains less than 0.1 % of 17-ol and only a trace of ketal formed by addition of ethanol to the 3-enol ether. 

Many complexes are unstable in 4.5 N H2SO4, which is used as electrolyte in the fuel cell, even at room temperature. Where tiffs was the case, measurements were carried out in potassium carbonate/potassium bicarbonate buffer solution (pH 9.3). We were thus able to determine the reactivity of a wide range of substances, in particular for the catalytic reduction of oxygen. 

After sterilization, yeast is added to initiate fermentation. McConnell and Schramm (1995) recommend inoculation with no less than 10% by volume. Moreover, as the pH of honey is naturally low and because it is poorly buffered, the pH of must may drop during fermentation to a point limiting yeast efficiency. pH reduction can result from the synthesis of acetic and succinic acids by the yeast cells (Sroka and Tuszynski, 2007). While a rapid decline in pH inhibits undesirable microbial activity (Sroka and Tuszynski, 2007), it also reduces the dissociation of fatty acids in the wort, potentially slowing yeast metabolic action. For this, addition of a buffer is important to maintain the pH within a range of 3.7-4.0 throughout fermentation (McConnell and Schramm, 1995). Calcium carbonate, potassium carbonate, potassium bicarbonate, and tartaric acid are potential candidates. However, as some of these salts can add a bitter-salty... 

The original procedure for the bromination-oxidation-reduction route used bromine in aqueous potassium hydroxide, followed by oxidation with nitric acid-hydrogen peroxide and reduction with alkaline ethanol. This procedure was improved by using NBS in aqueous sodium bicarbonate for the initial oxime bromination, followed by oxidation with nitric acid and final reduction of the Q -bromonitroalkane with sodium borohydride in methanol. It is possible to convert oximes to nitroalkanes via this procedure without isolating or purifying any of the intermediates. This procedure is reported to give yields of between 10 and 55 % for a range of oxime to nitroalkane conversions. ... 

Drugs of this group inhibit activity of carbonic anhydrase, an enzyme that catalyzes the reversible reaction of water and carbon dioxide, which forms carbonic acid. The mechanism of action of this group of drags is not fuUy understood. However, inhibition of carbonic anhydrase activity leads to a reduction of carbonic acid formation and an increase in bicarbonate, sodium, and potassium excretion with urine, which eventually leads to a significant increase in the process of excreting water from the organism. 

Acid-base and electrolyte balance High therapeutic dose especially when used in rheumatic fever, stimulates respiration and causes respiratory alkalosis. Reduction in bicarbonate and potassium level reduces the buffering capacity of the extracellular and intracellular fluid. Hypokalemia may lead to dehydration and hypernatremia. They also interfere with carbohydrate metabolism resulting in accumulation of pyruvic acid and lactic acid. 

Isoxazoles have been used to transpose functionality within a,/3-unsaturated carbonyl compounds (72JA9128). Thus, on exposing either (E)- or (Z)-/3-ionone oxime (449) to a mixture of iodine-potassium iodide in hot aqueous THF containing sodium bicarbonate, the isoxazole (450) was formed in high yield. Catalytic reduction of this isoxazole led... 

To estimate arsenite and arsenate when present together, the former may first be determined in a portion of the solution by titration with iodine in the presence of sodium bicarbonate. Another portion is acidified strongly with hydrochloric acid, some ferrous sulphate and potassium bromide are added and the whole of the arsenic is distilled off as chloride and collected in water.2 The reduction may also be accomplished by cuprous chloride.3 The arsenious acid in the aqueous distillate is determined as above and the arsenic acid found by difference. 

A one-pot, two-step reaction of the pyrazolodithiazolium chlorides (29) afforded the 5H-pyrazolo[3,4-c/]-l,2,3-thiadiazoles (41), representing a new heterocyclic ring system (Scheme 25). Hydrolysis and reduction of the salts (29) with base and sodium dithionite followed by treatment with sodium nitrite and subsequent acidification afforded derivatives (41) (30-55%). Potassium hydroxide was the base of choice for substrates (29a,b), while sodium bicarbonate was found to be superior for substrates (29c,d). A significant quantity of disulfide (43) may form on reaction of compound (29c) this can be converted in situ, or isolated and converted to the desired product (41c) in good yield (Scheme 25) <84JOCi224>. 

Isoxeaoks. Oximes of certain oi, -unsaturated ketones are oxidized by iodine-potassium iodide in aqueous THF containing sodium bicarbonate to isoxazoles. Thus treatment of the oxime of either (E)- or (Z)-P-ionone (1) with this combination of reagents gives the isoxazole (2) in 91 % yield. The expensive potassium iodide is needed only in catalytic amount. Reduction of (2) tvith sodium and 3 eq. of (-butanol in liquid... 

Reduction of urine acidity can be accomplished by the administration of sodium bicarbonate or Shohl s solution (40 g citric acid and 98 g sodium citrate per liter). With the former, 2 to 6 g/day is given in equally divided doses at 6- to 8-hour intervals. A dose of 20 to 60 mL of ShohTs solution per day, given in three or four divided doses, provides an equivalent amount of alkali. If use of a sodium salt is contraindicated, potassium citrate may be used instead. 

The marked increase in the serum urea with the modest increase in the serum creatinine would indicate the presence of pre-renal uraemia. Pyrexial patients are frequently hypercatabolic which will contribute to his high serum urea. His urine osmolality of 629 mmol/kg would support this, for if his pre-renal uraemia were purely due to dehydration his urine osmolality would be much higher. His low serum bicarbonate and high anion gap indicates that he has a metabolic acidosis. This acidosis will cause the potassium to move from the intracellular to the extracellular compartment. The reduction in his glomerular filtration rate results in his inability to maintain a normal serum potassium in the face of this efflux as both these factors contribute to his hyperkalaemia. 

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