Potassium bicarbonates

Potassium bicarbonate (poe-TAS-ee-yum buy-KAR-bo-nate) is a colorless crystalline solid or white powder with no odor and a salty taste. It occurs naturally in salt beds, sea water, silicate rocks, and a number of foods, primarily fruits and vegetables. Potassium bicarbonate is also present in the tissues of humans and other animals, where it is involved in a number of essential biological processes, including digestion, muscle contraction, and heartbeat. It is used primarily in cooking and baking, as a food additive, and in fire extinguishers. 

Potassium bicarbonate is made by passing carbon dioxide gas through an aqueous solution of potassium carbonate K2C03 + C02 + H20 - 2KHCO3 

One of the most familiar applications of potassium bicarbonate is as an antacid to treat the symptoms of upset stomach. The compound reacts with stomach acid-hydrochloric acid  

Potassium bicarbonate. Red atoms are oxygen, white atom is hydrogen black atom is carbon and turquoise atom is potassium. Gray stick indicates double bond, publishers 

HCl-to relieve gaseous distress, stomach pain, and heartburn. The compound can also he used to treat potassium deficiency in the body. Some research suggests that potassium bicarbonate may help restore muscle and bone tissue, particularly in women with the degenerative bone disease osteoporosis. The compound is also used as a food additive, as a leavening agent, to maintain proper acidity in foods, to supply potassium to a diet, and to provide the bubble and fizz in carbonated drinks. 

BP Potassium bicarbonate PhEur Kalii hydrogenocarbonas USP Potassium bicarbonate 

Potassium bicarbonate occurs as colorless, transparent crystals or as a white granular or crystalline powder. It is odorless, with a saline or weakly alkaline taste. 

Carbonic acid monopotassium salt E501 monopotassium carbonate potassium acid carbonate potassium hydrogen carbonate. 

As an excipient, potassium bicarbonate is generally used in formulations as a source of carbon dioxide in effervescent preparations, at concentrations of 25-50% w/w. It is of particular use in formulations where sodium bicarbonate is unsuitable, for example, when the presence of sodium ions in a formulation needs to be limited or is undesirable. Potassium bicarbonate is often formulated with citric acid or tartaric acid in effervescent tablets or granules on contact with water, carbon dioxide is released through chemical reaction, and the product disintegrates. On occasion, the presence of potassium bicarbonate alone may be sufficient in tablet formulations, as reaction with gastric acid can be sufficient to cause effervescence and product disintegration. 

Potassium bicarbonate has also been investigated as a gasforming agent in alginate raft systems.  

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JNH HCO, and potassium bicarbonate [298-14-6] KHCO, are used as well. When used alone, sodium bicarbonate reacts to give products a bitter, soapy flavor. Thus it is always combiaed with a leavening acid. 

Some dry-chemical fire extinguishers contain sodium or potassium bicarbonate these should not be used on nitromethane or nitroethane fires. Dry chemical extinguishers can be used on nitropropane fires. 

Benzenetetrol. 1,2,3,5-Tetrahydroxybenzene (64) forms needles (mp 165°C) from water. The compound is easily soluble ia water, alcohol, and ethyl acetate and is iasoluble ia chloroform and benzene. In aqueous potassium bicarbonate solution sparged with carbon dioxide,... 

Potassium bicarbonate is used in foods and medicine. It is approximately twice as effective as NaHC03 in dry-powder fire extinguishers, perhaps because the potassium affects the free-radical mechanism of flame propagation. However, the material does not have good handling characteristics. 

Amino-2-hydroxybenzoic acid is manufactured by carboxylation of 3-amiaophenol under pressure with ammonium carbonate at 110 °C (182) or with potassium bicarbonate and carbon dioxide at 85—90°C (183) with subsequent acidification. 

A.ctivated Carbonate Process. The activated carbonate process is based on absorption of CO2 by potassium carbonate (57) to give potassium bicarbonate. When the bicarbonate is heated it releases CO2, regenerating potassium carbonate. 

Other bicarbonates of considerable commercial importance are ammonium bicarbonate [1066-33-7] and potassium bicarbonate [298-14-6]. These compounds are decomposed by the oven heat, Hberating ammonia, carbon dioxide, and water to faciUtate leavening action. Their uses are limited to low moisture products such as cookies and crackers. 

Potassium Carbonate Process. The potassium carbonate process is similar to the sodium carbonate process. However, as potassium bicarbonate [298-14-6] is more soluble than the corresponding sodium salt, this process permits a more efficient absorption than the other. The equipment layout is the same and the operation technique is similar. 

Partly because of their low cost, aqueous solutions of sodium or potassium carbonate also are used for CO9 and H9S. Potassium bicarbonate has the higher solubility so the potassium salt is preferred. In view of the many competitive amine and carbonate plants that are in operation, fairly close figuring apparently is required to find an economic superiority, but other intangibles may be involved. 

Potassium bicarbonate [298-14-6] M 100.1. Crystd from water at 65-70° (1.25mL/g) by filtering, then cooling to 15°. During all operations, CO2 is passed through the stirred mixture. The crystals, sucked dry at the pump, are washed with distilled water, dried in air and then over H2SO4 in an atmosphere of CO2. 

The seventh element in order of abundance in the Earth s crust is potassium - about the same as sfjdium with similar properties. While sodium is readily available from the ocean, potassium is found and extracted from many mineral formations. About 90 percent of the potassium that is extracted goes to the production of fertilizers. Other purposes for it are ceramics and fire extinguishers for which potassium bicarbonate is better than sodium bicarbonate. 

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. 

To the epoxide dissolved in a minimal amount of chloroform or ether is added a corresponding solution of freshly prepared thiocyanic acid (20 fold excess) as described above (acetic acid has also been used as solvent). The resulting solution is allowed to stand at least 70 hr at room temperature. (Some workers have protected the reaction mixture from light during this period). The reaction mixture is worked up by washing first with a 10% solution of sodium carbonate, sodium bicarbonate or potassium bicarbonate, and then water. The remaining ether extract is dried (Na2S04) and evaporated under vacuum. The crude thiocyanatohydrin is crystallized from an appropriate solvent or treated with methanesulfonyl chloride s (see below). 

Preparation of 3a-Hydroxy-5) -pregn-17(20)-en-21-oic Acid . A solution of 15 g of 3a-acetoxy-5jS-pregnan-20-one in 290 ml of glacial acetic acid is treated with 13 g of bromine at room temperature. After complete addition of bromine the reaction mixture is heated at 40-50° for 30 min, and the product precipitated with water and filtered. The product is taken up in ethyl acetate (500-600 ml) and the resulting solution washed with dilute aqueous potassium bicarbonate. The solvent is concentrated in vacuo and the product crystallized from acetone to give 16g of dibromide mp, 173-175°. 

Hydrolysis of the intermediate epoxy acetate is generally carried out with strong alkali if base-sensitive groups are present, milder conditions (e.g., potassium bicarbonate, potassium carbonate) can be employed. If commercial peracetic acid (which contains sulfuric acid) is used for epoxidation, the intermediate epoxy acetate cannot be isolated, but is hydrolyzed in situ by the acid to the desired ketol. Acid hydrolysis will also retain 3-acetates, if present. ... 

A solution of the bromo ketone (1 g) and sodium iodide (1 g) in 40 ml of acetone is refluxed for 20 min. The hot solution is filtered and the filtrate added to a mixture of 5 g of potassium bicarbonate and 4 ml of acetic acid. This mixture is then refluxed overnight, cooled and poured into a large excess of water. The resulting white precipitate is collected by filtration, dried in vacuo and finally recrystallized twice from methanol to afford 0.49 g of 3, 21-diacetoxypregna-5,16-dien-20-one mp 153-155° [a]jj —40° (CHCI3). 

The solution concentration for a potassium carbonate system is limited by the solubility of the potassium bicarbonate (KHCO3) in the rich... 

A solution of 88.5 parts of L-phenylalanine methyl ester hydrochloride in 100 parts of water is neutralized by the addition of dilute aqueous potassium bicarbonate, then is extracted with approximately 900 parts of ethyl acetate. The resulting organic solution is washed with water and dried over anhydrous magnesium sulfate. To that solution is then added 200 parts of N-benzyloxycarbonyl-L-aspartic acid-a-p-nitrophenyl, -benzyl diester, and that reaction mixture is kept at room temperature for about 24 hours, then at approximately 65°C for about 24 hours. The reaction mixture is cooled to room temperature, diluted with approximately 390 parts of cyclohexane, then cooled to approximately -18°C in order to complete crystallization. The resulting crystalline product is isolated by filtration and dried to afford -benzyl N-benzyloxycarbonvI-L-aspartyl-L-phenylalanine methyl ester, melting at about 118.5°-119.5°C. 

The pH of the mixture was adjusted to 7.5 by adding a saturated sodium bicarbonate solution. After being washed twice with diethyl ether, the reaction solution was acidified to pH 2 with dilute hydrochloric acid and extracted with ether. The ether solution containing the free penicillin was washed twice with water and then extracted with 50 ml of N potassium bicarbonate solution. After freeze drying of the obtained neutral solution, the potassium salt of o-azidobenzylpenicillin was obtained as a slightly colored powder (11.2 grams, 54% yield) with a purity of 55% as determined by the hydroxylamine method (the potassium salt of penicillin G being used as a standard). 

A mixture of 200 grams of 2-benzoyloxyethanol in 2 liters of pyridine at -5°C is treated with 275 grams of p-toluenesulfonyl chloride and the resulting mixture is stirred at O C for 2 hours. Water is added slowly at O " to 5°C. Extracting with chloroform, washing the extract with dilute hydrochloric acid, water and potassium bicarbonate, and evaporating the solvent leaves benzyloxyethyl p-toluenesulfonate. 

Methylprednisone-21 -ecetate Potassium bicarbonate Bacterium Bacillus sphaericus var. fusifermis Nutrient broth... 

Methylprednisone 21-acetate (0.5 g), when hydrolyzed by means of aqueous alcoholic potassium bicarbonate yields 16 fnethylprednisone. An alternative method of the preparation of the compound of this example is as follows. Bacillus sphaericus var. fusifermis (A.T.C.C. 7055) is incubated on a nutrient agar (composed of Bacto-beef extract, 3 g Bacto-peptone,... 

To a solution of 6.36 parts of 17(3-hydroxy-17a-methyl-5o -androst-Ten-3-one in 95 parts of acetic acid and 12 parts of water is added 40 parts of lead tetracetate and 0.6 part of osmium tetroxide. This mixture is stored at room temperature for about 24 hours, then is treated with 2 parts of lead tetracetate. Evaporation to dryness at reduced pressure affords a residue, which is extracted with benzene. The benzene extract is washed with water, and extracted with aqueous potassium bicarbonate. The aqueous extract is washed with ether, acidified with dilute sulfuric acid, then extracted with ethyl acetate-benzene. This organic extract is washed with water, dried over anhydrous sodium sulfate, and concentrated to dryness in vacuo. To a solution of the residual crude product in 20 parts of pyridine is added 10 parts of 20% aqueous sodium bisulfite and the mixture is stirred for about 20 minutes at room temperature. 

An aqueous slurry of 6 parts of 17/3-hydroxy-17a -methyl-1-oxo-1,2-seco-A-nor-5a -androstan-2-oic acid in 200 parts of water is made alkaline to pH 10 by the addition of dilute aqueous sodium hydroxide, then is treated with 6 parts of sodium borohydride. This mixture is allowed to react at room temperature for about 3 hours. Benzene is added and the resulting mixture is acidified carefully with dilute hydrochloric acid. The benzene layer is separated, and the aqueous layer is further extracted with benzene. The combined benzene extracts are washed successively with aqueous potassium bicarbonate and water, dried over anhydrous sodium sulfate, then evaporated to dryness in vacuo. The resulting residue is triturated with ether to afford pure 17/3-hydroxy-17a -methyl-2-oxa-5a -androstan-3-one,... 

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