Acetates sodium

Sodium acetate (SO-dee-um ASS-uh-tate) is a colorless, odorless crystalline solid that often occurs as the trihydrate NaCjHjOj HjO. A hydrate is a chemical compound formed when one or more molecules of water is physically added to the molecule of some other substance. Sodium acetate trihydrate has three molecules of water of hydration for every NaC2H302 unit. Anhydrous sodium acetate readily converts to the trihydrate because it is very hygroscopic. A hygroscopic compound is one that readily absorbs moisture from the air. 

Sodium acetate is prepared by reacting either sodium hydroxide (NaOH) or sodium carbonate (Na2C03) with acetic acid (HC2H302). With sodium hydroxide, for example, the reaction is  

The sodium acetate forms as the trihydrate, which is then recovered by evaporating the reacting solution. The 

Sodium acetate trihydrate. Red atoms are oxygen hydrogen atoms are white black atoms are carbon turquoise atom is sodium. Gray stick indicates double bond. PUBLISHERS RESOURCE GROUP 

Sodium acetate is used in a number of industries. In the textile industry, it is used as a mordant in the dyeing of fabrics and to stabilize and improve the finish of fabrics. The 

BP Sodium acetate JP Sodium acetate PhEur Natrii acetas trihydricus USP Sodium acetate 

Acetic acid, sodium salt E262 sodium ethanoate. 

Note that the trihydrate is the material described in the JP2001, PhEur 2005 and USP 28, although the PhEur 2005 is the only pharmacopeia that makes this explicit with the title of the monograph. 

Antimicrobial preservative buffering agent flavoring agent, stabilizing agent. 

Sodium acetate is used as a buffering agent in various intramuscular, intravenous, topical, ophthalmic, nasal, oral, otic, and subcutaneous formulations. It may be used to reduce the bitterness of oral pharmaceuticals. It can be used to enhance the antimicrobial properties of formulations it has been shown to inhibit the growth of S. aureus and E. coli, but not C. albicans in protein hydrolysate solutions. It is widely used in the food industry as a preservative. Sodium acetate has also been used therapeutically for the treatment of metabolic acidosis in premature infants, and in hemodialysis solutions.  

The following reagents are employed for the prepara tion of acetyl derivatives from organic compounds con 

Acetyl bromide has been used for the acetylation of certain sugars the products are aceto bromides and usually crystallize well. 

This reagent has also been employed occasionally. A collection has been made of references in the literature to hydroxyl derivatives which are not capable of acetylation. Vide also p. 143. 

Acetyl derivatives are isolated by pouring the product of the reaction into water. The excess of acetic acid may also be removed by the addition of methyl c 

The various acetyl derivatives of a compound usually differ little in percentage composition, so that elementary analysis seldom affords information as to the number of acetyl groups which have entered the orig- 

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Streaming potential measurements are to be made using a glass capillary tube and a particular electrolyte solution, for example, O.OIM sodium acetate in water. Discuss whether the streaming potential should or should not vary appreciably with temperature. 

Since hydroxylamine is usually available only in the form of its salts, e.g., the hydrochloride or sulphate, the aqueous solution of these salts is treated with sodium acetate or hydroxide to liberate the base before treatment with the aldehyde or ketone. Most oximes are weakly amphoteric in character, and may dissolve in aqueous sodium hydroxide as the sodium salt, from which they can be liberated by the addition of a weak acid, e.g., acetic acid. 

The residual liquid in the flask is a dilute alkaline solution of sodium acetate. To liberate the acetic acid, add dilute sulphuric acid until the solution is definitely acid to litmus, and then distil off about 20 ml. Perform on this aqueous distillate the tests for acetic acid given on p. 347-... 

For complete acetylation of polyhydric compounds, such as glucose (p. 141) and mannitol (p. I42), even undiluted acetic anhydride is insufficient, and a catalyst must also be employed. In such cases, the addition of zinc chloride or anhydrous sodium acetate to the acetic anhydride usually induces complete acetylation. ... 

Required Anhydrous sodium acetate, 21 g. acetyl chloride, IS ml. 

For this preparation, it is particularly necessary that the sodium acetate should be free from traces of water. The anhydrous material can be prepared by gently heating the hydrated salt (CHsCOONa,3HjO) in an esaporating-basin over a small Bunsen flame. The salt dissolves in its water of ciystallisation and resolidifies as this water is driven off further heating then causes the anhydrous material to melt. Stir the molten anhydrous material to avoid charring, and then allow it to cool in a desiccator. Powder the cold material rapidly in a mortar, and bottle without delay. 

Dissolve 36 g. of sodium hydroxide in 160 ml. of water contained in a 500 ml. conical flask, and chill the stirred solution to 0-5° in ice-water. Now add io-8 ml. (32-4 g.) of bromine slowly to the stirred solution exercise care in manipulating liquid bromine ) during this addition the temperature rises slightly, and it should again be reduced to 0-5°. Add a solution of 12 g. of acetamide in 20 ml. of water, in small portions, to the stirred hypobromite solution so that the temperature of the mixture does not exceed 20° the sodium acet-bromoamide is thus obtained in the alkaline solution. Now remove the flask from the ice-water, and set it aside at room temperature for 30 minutes. 

B) [i-PENTACETYLGLUCOSE. Required Anhydrous sodium acetate, 2 5 g. acetic anhydride, 25 ml. glucose, 5 g. 

Carry out this preparation precisely as described for the a-compound, but instead of zinc chloride add 2 5 g. of anhydrous powdered sodium acetate (preparation, p. 116) to the acetic anhydride. When this mixture has been heated on the water-bath for 5 minutes, and the greater part of the acetate has dissolved, add the 5 g. of powdered glucose. After heating for I hour, pour into cold water as before. The viscous oil crystallises more readily than that obtained in the preparation of the a-compound. Filter the solid material at the pump, breaking up any lumps as before, wash thoroughly with water and drain. (Yield of crude product, io o-io 5 g.). Recrystallise from rectified spirit until the pure -pentacetylglucose is obtained as colourless crystals, m.p- 130-131° again two recrystallisations are usually sufficient for this purpose. 

Mannitol, CH,0H(CH0Hi4CH40H, is a hexahydric alcohol obtained by the reduction of mannose. Since ring formation does not occur in mannitol, the hexacetyl derivative can exist in only one form, and therefore either zinc chloride or sodium acetate can be used as a catalyst for the acetylation. 

Place 80 g, of hydroxylamine sulphate (or 68-5 g. of the hydrochloride), 25 g. of hydrated sodium acetate, and 100 ml. of water in a 500 ml. flask fitted with a stirrer and a reflux water-condenser, and heat the stirred solution to 55-60°. Run in 35 g (42 nil,) of -hexyl methyl ketone, and continue the heating and vigorous stirring for ij hours. (The mixture can conveniently be set aside overnight after this stage.) Extract the oily oxime from the cold mixture twice with ether. Wash the united ethereal extract once with a small quantity of water, and dry it with sodium sulphate. Then distil off the ether from the filtered extract, preferably using a distillation flask of type shown in Fig. 41 (p. 65) and of ca, 50 ml, capacity, the extract being run in as fast as the ether distils, and then fractionally distil the oxime at water-pump pressure. Collect the liquid ketoxime, b.p. 110-111713 mm. Yield, 30-32 g. 

Phenylhydrazine is usually dissolved in acetic acid for hydrazone formation if a salt of phenylhydrazine with an inorganic acid is used, it must be mixed with an excess of sodium acetate (see preparation of osazones, p. 137). 

Cinnamic acid is usually prepared by Perkin s reaction, benzaldehyde being heated with sodium acetate in the presence of acetic anhydride. It is probable that the benzaldehyde and the acetic anhydride combine under the catalytic action of the sodium acetate, and the product then readily loses water to give mono-benzylidene acetic anhydride (. ). The latter, when subsequently... 

Required Benzaldehyde, 20 ml. acetic anhydride, 30 ml. anhydrous sodium acetate, 10 g. 

This compound is similar in type to the sodium acet-bromoamide, CHjCONNaBr, which is an intermediate compound in Hofmann s amine synthesis (p. 127). If a weak acid (such as acetic acid) is now added to the solution of the chloro-sodio-amide, the latter compound reacts with the hypo-chlorous acid giving the sulphon-dichloro amide, which being insoluble in water, rapidly separates ... 

Aldehydes and ketones may frequently be identified by their semicarbazones, obtained by direct condensation with semicarbazide (or amino-urea), NH,NHCONH a compound which is a monacidic base and usually available as its monohydrochloride, NHjCONHNH, HCl. Semicarbazones are particularly useful for identification of con jounds (such as acetophenone) of which the oxime is too soluble to be readily isolated and the phenylhydrazone is unstable moreover, the high nitrogen content of semicarbazones enables very small quantities to be accurately analysed and so identified. The general conditions for the formation of semicarbazones are very similar to those for oximes and phenylhydrazones (pp. 93, 229) the free base must of course be liberated from its salts by the addition of sodium acetate. 

Required Semicarbazide hydrochloride, i g. anhydrous sodium acetate, 0-9 g. acetophenone, i ml. 

Add first I g. of powdered semicarbazide hydrochloride and then 0 9 g. of anhydrous sodium acetate (or 1-25 g. of the crystalline acetate) to 5 ml. of water, and warm gently until a clear solution is obtained. Then add a solution of i ml. (i g.) of acetophenone in 5 ml. of rectified spirit, and warm the mixed solutions gently on a water-bath for... 

Coumarin is usually prepared by heating salicylaldehyde with acetic anhydride and sodium acetate (i.e., the Perkin cinnamic acid synthesis, p. 23 6), whereby the 0" hydroxy-cinnamic acid (I) undergoes cyclisation to coumarin. Coumarins having substituents in the benzene ring can often be similarly prepared. 

Sodium acetate CH3COONa Sodium succinate (CHaCOONa), Sodium benzoate CeHjCOONa Sodium formate HCOONa i Sodium oxalate fCOONa) J Sodium salicylate HOCeH COONa... 

Ethyl acetate test. Heat i ml. of ethanol with 0-5 g. of sodium acetate and a few drops of cone. H2SO4 gently for about i minute. Cool and pour into a few ml. of water in a boiling-tube. Note fruity odour of the ethyl acetate. 

A) Semicarbazones. Prepared according to the directions given for acetophenone semicarbazone (p. 258), but use twice the amount of semicarbazide hydrochloride and sodium acetate. (M.ps., p. 549.)... 

If the commercial fused sodium acetate is available, it should be melted and maintained in the fused state for several minutes in order to remove the water absorbed during storage. 

Dissolve 2 5 g. of hydroxylamine hydrochloride and 4 g. of crystallised sodium acetate in 10 ml. of water in a small flask or in a test-tube. Warm the solution to about 40° and add 2 5 g. of cyclohexanone. Stopper the vessel securely with a cork and shake vigorously for a few minutes the oxime soon separates as a crystalline solid. Cool in ice, filter the crystals at the pump, and wash with a little cold water. RecrystaUise from light petroleum, b.p. 60-80°, and dry the crystals upon filter paper in the air. The yield of pure cycZohexanone oxime, m.p. 90°, is 2 -5 g. 

Prepare a solution of phenylhydrazine by dissolving 1 0 g. of phenyl-hydrazine hydrochloride and 1 5 g. of crystallised sodium acetate in 10 ml. of water if the resulting solution is turbid, filter. Add a solution of 0 5 ml. of cycZohexanone in 8 ml. of water to the reagent... 

Semicarbazones. Dissolve 1 g. of semicarbazide hydrochloride and 1 5g. of crystallised sodium acetate in 8-10 ml. of water add 0 - 5-1 g. of the aldehyde or ketone and shake. If the mixture is turbid, add alcohol (acetone-free) or water until a clear solution is obtained shake the mixture for a few minutes and allow to stand. Usually the semicarbazone crystallises from the cold solution on standing, the time varying from a few minutes to several hours. The reaction may be accelerated,... 

Oximes. The method given for semicarbazones (see 2) may be employed use 1 g. of hydroxylamine hydrochloride, 2 g. of crystallised sodium acetate and 0 5 g. of the aldehyde or ketone. It is usually advisable to warm on a water bath for 10 minutes. 

Acetyl chloride Sodium acetate Acetic anhydride... 

An equivalent result may be obtained by treating excess of sodium acetate with phosphorus oxychloride acetyl chloride is an intermediate product and the final result is ... 

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