Bases Potassium bicarbonate

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. 

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. 

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. ... 

The base-catalyzed homogeneous WGS reaction was studied by Yoneda and coworkers as early as the 1940s.3-5 They ran water gas shift in aqueous solutions of potassium bicarbonate and formate3 in the range of 250-325 °C and 150 atm, and... 

Potassium bases, 20 604-605 Potassium benzoate, 3 632t, 633-634, 635 Potassium P-alumina, 2 406t Potassium bicarbonate, 20 632 Potassium bifluoride, 11 838 Potassium borohydride, 13 615, 620 production process for, 13 617 Potassium bromate, 4 334-335 20 630 Potassium bromide, 20 630... 

Tank car loading racks should be provided with one potassium bicarbonate dry chemical extinguisher (120-B C) at the base of the platform stairway. One (160-B C) unit should also be provided on the platform at every fourth tank car station. In addition, at least one potassium bicarbonate wheeled extinguisher (640-B C) should be located near the rack. 

The activated carbonate process is based on absorption of CO2 by potassium carbonate to give potassium bicarbonate (configuration 2). When potassium bicarbonate is heated it releases CO2 while potassium carbonate is formed back again. The original hot carbonate process was found too corrosive for carbon steel reactor walls. Nowadays, however, improvements in additives and optimisation of operation have made activated carbonate processes competitive with state-of-the-art MDEA systems. 

Contact with ammonia, strong acids may cause sensitization, which can lead to explosions. Mixtures with hydrocarbons and other combustible materials may cause fire and explosions. Incompatible with bases, metal oxides, hydroxides, potassium hydride, sodium bicarbonate, potassium bicarbonate. Attacks some plastics, rubber, and coatings. 

The waters were analyzed for Si02 (aq), aluminum, iron, magnesium, calcium, sodium, potassium, bicarbonate, chloride, and sulfate (Table II). The pH was measured in the field using a glass electrode. The average compositions of these waters are shown in Table III. The stream composition represents the average of 18 samples taken at base... 

Turnkey Process for Celiprolol Celiprolol has a unique Af,Af-diethylurea in its structural framework we wished to integrate HKR into a process. The existing route starts with 4-ethoxyaniline which was treated with diethylcarbamoyl chloride in the presence of potassium bicarbonate to give A -p-ethoxyphenylacetamide (Scheme 30.7). Friedel-Crafts acylation with acetyl chloride and anhydrous aluminum chloride followed by acid hydrolysis furnished the acetophenone derivative. Reaction of the urea derivative with epichlorohydrin followed by treatment with hydrobromic acid yielded a bromohydrin. Celiprolol was obtained as a free base by reaction of this bromohydrin with feri-butylamine in the presence of triethylamine, and was later converted to its hydrochloride salt. 

Analysis of the gas phase after 73 h gave a composition of 5.6% H2, 6.5% CO2, plus 88% CO, while analysis after 144 h gave 10.4% H2, 8.5% CO2, plus 77% CO. Also, the catalyst activity remains approximately constant or is perhaps slightly enhanced after flushing the system with fresh CO and restarting. When the temperature of reaction solutions is raised to 110 °C the rate of H2 formation is approximately quadrupled over that at 100 °C and a similar increase is noted again for the 10 °C raise to 120 °C. Over a period of 30 days the total hydrogen produced by this system equalled 3 x 10 mol, which represents a ratio of 150 mol of H2 per mole of Ru3(CO)i2 initially added or 3 mol of H2 per mole of KOH added. Thus, formation of H2 clearly exceeds the molar quantities of KOH and Ru3(CO)i2 added and thus cannot represent the stoichiometric reaction of base with coordinated carbon monoxide. That this system can be catalytic in base imdoubtedly results from the fact that under the reaction conditions potassium bicarbonate in ethoxyethanol is unstable and decomposes to CO2 plus KOH. 

Aqueous alkali or basic medium is generally used as the catalyst for the preparation of epoxy resins. Useful base compounds include alkali and alkaline earth metal bicarbonates, carbonates, hydroxides or hydrides or alkoxides. A few of such compounds are sodium carbonate (Na2C03), potassium carbonate (K2CO3), lithium carbonate (Li2C03), calcium carbonate (CaC03), sodium hydroxide (NaOH), potassium hydroxide (KOH), lithium hydroxide (LiOH), calcium hydroxide (Cao.sOH), sodium bicarbonate (NaHC03), potassium bicarbonate (KHCO3), lithium bicarbonate... 

When solutions of chromium(III) nitrate and potassium bicarbonate are mixed, a gas bubbles off and a light-green precipitate forms. Write a net ionic equation and explain the acid-base reactions. 

Thiols. 5-Acetyl derivatives can be prepared by the reaction of acetic anhydride and a thiol in the presence of potassium bicarbonate. Several disadvantages to the 5-acetyl group in peptide synthesis include /3-elimination upon base-catalyzed hydrolysis. Also, sulfur to nitrogen acyl migration may be problematic. 

The original screening study used mefeylamine, potassium bicarbonate, potassium carbonate, ethanolamine, lithium hydride, dibasic potassium phosphate, potassium t-butoxide, DBU, potassium mefeoxide and N,N-diisopropylefeylamine as representative bases. Solvents included in fee screen were water, tetrahydrofuran, acetonitrile, ethyl acetate, methanol, ethanol, and 2-propanol. A tofel of 66 experiments was performed using 50 pinole (12 mg) of substrate, 2 equivalents of base, and 0.2 mL of solvent in each reaction. All... 

Additional vapor-liquid equilibrium data based on published iitformation and ejqterimen-tal work have been reported by Bocard and Mayland (1962). Other physical data on the potassium carbonate-potassium bicarbonate-carbon dioxide system are shown in Figures 5-11 to 5-14. The data of Bocard and Mayland (1962) have been converted to a series of nomographs by Mapstone (1966). 

A high yield chemical pulp, eg, 52—53% bleached yield from softwoods, can be obtained, but strength properties ate inferior to those obtained from the kraft process. If a protector, eg, potassium iodide, is added, an additional 2—3% yield is obtained, as is an improvement in all strength properties. The gas penetration problem can be minimized if ftbetization is accompHshed before treatment with oxygen. Oxygen treatment of virtually all types of semichemical and mechanical pulps has been explored (55). Caustic, sodium bicarbonate, and sodium carbonate have been used as the source of base (56,57). In all cases, the replacement of the kraft by these other processes has not been justified over the alternative of pollution abatement procedures. 

However, many salts such as the hydroquinone or biphenol salt are so insoluble diat they do not work well by this procedure. Furthermore, a stoichiometric amount of base used for die reaction is critical to obtain high-molecular-weight polymers. Moreover, die sd ong base may undesirably hydrolyze the dihalides to afford deactivated diphenolates, which upset the stoichiometry. Clendining et al. reported that potassium carbonate or bicarbonate could be used in these reactions instead of corresponding hydroxides.60 McGrath and co-workers were the first to systematically study die use of the weak base K2C03 instead of a strong base to obtain phenolate salts.8,61,62 Potassium carbonate was found to be better than... 

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