Sodium acetate bicarbonate

Sodium acetate reacts with carbon dioxide in aqueous solution to produce acetic anhydride and sodium bicarbonate (49). Under suitable conditions, the sodium bicarbonate precipitates and can be removed by centrifugal separation. Presumably, the cold water solution can be extracted with an organic solvent, eg, chloroform or ethyl acetate, to furnish acetic anhydride. The half-life of aqueous acetic anhydride at 19°C is said to be no more than 1 h (2) and some other data suggests a 6 min half-life at 20°C (50). The free energy of acetic anhydride hydrolysis is given as —65.7 kJ/mol (—15.7 kcal/mol) (51) in water. In wet chloroform, an extractant for anhydride, the free energy of hydrolysis is strangely much lower, —50.0 kJ/mol (—12.0 kcal/mol) (51). Half-life of anhydride in moist chloroform maybe as much as 120 min. Ethyl acetate, chloroform, isooctane, and / -octane may have promise for extraction of acetic anhydride. Benzene extracts acetic anhydride from acetic acid—water solutions (52). 

Into a suspension of 8 g of sodium acetate m 400 mL of a solution of 1 part acetic acid and 10 parts fluorotnchloromethane is passed at -75 C a stream of fluonne diluted to 10% with nitrogen The reacuon is stirred with a Vibromixer A solution of 4-methylacetanilide (20 mmol) in a mixture of dichloromethane and fluorotnchloromethane cooled to -75 °C i s added to 20 mmol of acetyl hypofluonte as determined by titration with potassium iodide After 5 min the mixture is poured into water, and the orgamc layer is washed with sodium bicarbonate soluaon and dried over anhydrous magnesium sulfate After concentrauon and column chromatography over silica gel and elution with chloroform, 2-fluoro-4-methylacetanilide IS obtained m 85% yield... 

B. N-Nitroso-N-(2-phenylethyl)benzamide. A solution of 10.4 g. (0.046 mole) of the crude N-(2-phenylethyl)benzamide, 7.36 g. (0.09 mole) of anhydrous sodium acetate, and-50 ml. of glacial acetic acid is placed in a 250-ml. Erlenmeyer flask equipped with a drying tube, and the mixture is cooled to the crystallization point of the acetic acid (Note 1). A solution of dinitrogen tetroxide (Notes 2, 3) in glacial acetic acid (85 ml. of a solution approximately 1M in N2O4) is then added with stirring. The reaction mixture is allowed to warm to about 15° (15 minutes), and then it is poured into a mixture of ice and water. The yellow solid nitroso derivative is dissolved in 75 ml. of carbon tetrachloride, and this solution is washed with 5% sodium bicarbonate, water, and dried. The solution is used directly in the next step. 

Tetrakis(tripheiiylphosphine)palladium(0) is often used for this reaction. However, Pd(II) complexes such as bis(triphenylphosphine)palladium dichloride or palladium acetate are also commonly employed for convenience, as they are stable in ah. The base is typically a secondary or tertiary amine such as triethy-lamine. Weak bases such as sodium (potassium) acetate, bicarbonate, or carbonate are also used. 

Klyuchnikov et al. have described an alternative substrate for the cycli-zation process, namely o-hydroxylaminonitro derivatives. These entities, previously synthesized or generated in situ, cycle in presence of a base, i.e., sodium bicarbonate and sodium acetate, producing the 1,2,5-oxadiazole N-oxide system (Fig. 2) [21-23]. 

Acetylcyclohexanone. Method A. Place a mixture of 24-6 g. of cyclohexanone (regenerated from the bisulphite compound) and 61 g. (47 5 ml.) of A.R. acetic anhydride in a 500 ml. three-necked flask, fitted with an efficient sealed stirrer, a gas inlet tube reaching to within 1-2 cm. of the surface of the liquid combined with a thermometer immersed in the liquid (compare Fig. II, 7, 12, 6), and (in the third neck) a gas outlet tube leading to an alkali or water trap (Fig. II, 8, 1). Immerse the flask in a bath of Dry Ice - acetone, stir the mixture vigorously and pass commercial boron trifluoride (via an empty wash bottle and then through 95 per cent, sulphuric acid) as fast as possible (10-20 minutes) until the mixture, kept at 0-10°, is saturated (copious evolution of white fumes when the outlet tube is disconnected from the trap). Replace the Dry Ice-acetone bath by an ice bath and pass the gas in at a slower rate to ensure maximum absorption. Stir for 3 6 hours whilst allowing the ice bath to attain room temperature slowly. Pour the reaction mixture into a solution of 136 g. of hydrated sodium acetate in 250 ml. of water, reflux for 60 minutes (or until the boron fluoride complexes are hydrolysed), cool in ice and extract with three 50 ml. portions of petroleum ether, b.p. 40-60° (1), wash the combined extracts free of acid with sodium bicarbonate solution, dry over anhydrous calcium sulphate, remove the solvent by... 

Potassium phosphate injection Ringer s injection Lactated ringer s injection Sodium acetate injection Sodium bicarbonate injection Sodium chloride injection Sodium lactate injection Sodium phosphate injection... 

The sodium acetate-acetic acid combination is one of the most widely used buffers, and is usually referred to simply as acetate buffer. Other buffer combinations commonly employed in chemistry and biochemistry include carbonate-bicarbonate (sodium carbonate-sodium hydrogen carbonate), citrate (citric acid-trisodium citrate), phosphate (sodium dihydrogen phosphate-disodium hydrogen phosphate), and tris [tris(hydroxymethyl)amino-methane-HCl]. 

This procedure is a modification of the method described for the preparation of 2-chlorophenylhydroquinone.s 2-/>-Acetyl-phenylquinone has been prepared by carrying out the coupling in alcohol solution in the presence of sodium acetate instead of sodium bicarbonate.2 Reduction by zinc, acetic acid, and a small amount of concentrated hydrochloric acid yielded 2- -ace-tylphenylhydroquinone.2... 

The common ion effect must also be considered, since it affects each one of the crystallization equilibrium, both in supercritical and subcritical water. Adding sodium acetate, for instance, to a solution containing sodium salts would favour sodium bicarbonate precipitation (formed from oxidation of acetate), thus avoiding the precipitation of more corrosive salts, such as the chloride or sulfate [28],... 

C 2-Bromo-4-methylbenzaldehyde A 3-1. three-necked flask is equipped with an efficient stirrer, a dropping funnel (Note 2), and a thermometer. The aqueous 10% formaldoxime prepared in step A is placed in the flask, and to it are added 6 5 g (0.026 mole) of hydrated cupric sulfate, 1.0 g. (0 0079 mole) of sodium sulfite, and a solution of 160 g of hydrated sodium acetate in 180 ml. of water The solution is maintained at 10-15° by means of a cold-water bath and stirred vigorously. The neutral diazonium salt solution prepared in step B is slowly introduced below the surface of the formaldoxime solution (Notes 3 and 4). After the addition of the diazonium salt solution is complete, the stirring is continued for an additional hour and then the mixture is treated with 230 ml. of concentrated hydrochloric acid. The stirrer and the dropping funnel are replaced by stoppers, and the mixture is gently heated under reflux for 2 hours The flask is set up for steam distillation, and the reaction product is steam-distilled. The distillate is saturated with sodium chloride, extracted with three 150-ml portions of ether, and the ethereal extracts are washed successively with three 20-ml portions of a saturated sodium chloride solution, three 20-ml. portions of an aqueous 10% sodium bicarbonate solution, and again with three 20-ml portions of a saturated sodium chloride solution. 

C and THF (20 mL) was added. Sulfur dioxide was then passed through the surface of the mixture for 30 min. The mixture was warmed to ambient temperature and stirred for an additional 15 min. The volatiles were evaporated and to the residue was added water (50 mL) and sodium acetate trihydrate (9.55 g, 70.2 mmol). The solution was cooled on an ice bath and hydroxylamine-O-sulfonic acid (4.62 g, 40.9 mmol) was added. The mixture was stirred at ambient temperature for 1 h, extracted with ethyl acetate (3x100 mL) and the combined extracts were washed with a sodium bicarbonate solution, brine and dried over molecular sieves. Evaporation to dryness gave a viscous liquid (4.93 g), which was chromatographed (silica, eluting with 33% ethyl acetate-hexane) to give a solid 3-(2,5,5-trimethyl-l,3-dioxane-2-yl)-2-thiophenesulfonamide (2.47 g, 72%) m.p. 200°-202°C. 

The last one (6.2 g, 18.4 mmol) was converted into 3,4-dihydro-4-hydroxy-2-(2-methoxy)ethyl-2H-thieno[3,2-e]-l,2-thiazine-6-sulfonamide 1,1-dioxide (4.87 g, 77%) m.p. 187°C by using the reaction with n-butyl lithium in anhydrous THF at -40°C for 40 min, and then bubbling sulfur dioxide gas for 20 min after which time the mixture was warmed to room temperature. After 30 min at room temperature the mixture was concentrated the residue was dissolved in water, cooled (0°C), sodium acetate trihydrate was added followed by hydroxylamine-O-sulfonic acid. The reaction mixture was stirred at room temperature for 18 h after which time was basified with solid sodium bicarbonate and extracted with ethyl acetate. 

To a 5 L 3-neck round bottom flask was added the crude carbonylbenzyloxy-3-aminopropanal (115 g, 0.555 mol) followed by addition of water (400 mL) and methanol (1600 mL). The reaction mixture was maintained at 25°C throughout the course of the reaction. After the solution became homogeneous. (S)-Valine methyl ester hydrochloride (90.2 g, 0.538 mol) was added in one portion followed by rapid addition of sodium acetate trihydrate (151 g, 1.11 mol) and sodium cycanoborohydride (73.2 g, 1.17 mol). The reaction mixture was allowed to stir at room temperature for 0.5 hour and was concentrated in vacuo. To this solution, saturated aq sodium bicarbonate (400 mL) was added and the mixture was extracted with isopropyl acetate (1 L). The organic layer was washed with water, dried over sodium sulfate, and concentrated to yield 150 g of crude product, which was dissolved in isopropyl acetate (300 mL) and heptane (2400 mL). Dry HCI was bubbled in and an oily solid precipitated out of solution. The liquid was decanted away from and the solid was dissolved in dichloromethane (3 L). The solution was washed with water (600 mL) and saturated aq sodium bicarbonate (600 mL) and dried over sodium sulfate. It was concentrated in vacuo to yield 105 g (59%) of N-(N-(benzyloxycarbonyl-3-amino)-propyl)valine methyl ester as a light yellow oil. 

---