Potassium ethanoate

Colourless, volatile liquid with a strong pearlike odour, b.p. 138-5 C. Manufactured by heating amyl alcohol (1-pentanol) with potassium ethanoate and sulphuric acid or by heating amyl alcohol with ethyl ethanoate in the presence of a little sulphuric acid. Commercial... 

Exercise 17-11 The direct halogenation of aldehydes under either acidic or basic conditions is complicated by side reactions involving either oxidation of the aldehyde —CHO group or additions to the—CH—0 double bond. Therefore the synthesis of a-halo aldehydes by the procedure described for ketones is not of much practical value. a-Haio aldehydes can be prepared indirectly from the enol ethanoate of the aldehyde. The enol ethanoate is made by treating the aldehyde with ethanoic anhydride and potassium ethanoate. The overall sequence follows ... 

Write the structures of the intermediate products, B and C, and the steps involved in each of the reactions to produce A, B, C, and 2-bromopropanal. What is the function of potassium ethanoate in the formation of A (You may wish to review Sections 15-4D and 15-4E.)... 

The [2 + 2] cycloadduct of tetrafluoroethene and 1,3-cyclopentadiene, when pyrolyzed at 700° to 750° and 5-mm pressure, produces (as the result of a sigmatropic rearrangement Section 21-10) a mixture of two new substances, each having two double bonds. The pyrolysis mixture, when heated in aqueous ethanoic acid containing potassium ethanoate, forms tropolone in 70% yield. Write equations for the reactions involved, with particular attention to possible structures for the pyrolysis products. 

Acetic acid, potassium salt Diuretic salt EINECS 204-822-2 FEMA No. 2920 Octan draselny Potassium acetate Potassium ethanoate Sal diureticum. Dehydrating agent, textile conditioner, analytical reagent, medicine, cacodylic derivatives, crystal glass, synthetic flavors. An alkalizer has been used to treat veterinary cardiac arrhythmias. Crystals mp = 292° d = 1.8000 soluble in H2O (200 g/100 ml), poorly soluble in organic solvents LDso (rat orl) = 3.25 g/kg. Am. Inti. Chem. EM Ind Inc. General Chem Heico Honeywell Stein Niacet. 

The use of chiral substrates has allowed the importance of solvent and nucleophile-associated cation to be probed. For example, as shown in Scheme 7.10, when chiral 1-chloro-l-phenylethane is heated in ethanoic acid (acetic acid,CH3C02H]) at 50°C in the presence of potassium ethanoate (potassium acetate, CH3C02 K+), the ethanoic acid (acetic acid, CH3CO2H) ester of 1-phenylethanol is obtained. In this weakly nucleophilic system, about 15% excess inverted product is found (i.e., 85% of the product is racemic and the substitution reaction occurred with about 57.5% inversion and 42.5% retention). Presumably, the carbocation formed first and then... 

Potassium ethanoate CH3COOK [CH3COO- K1 Ethanoate and potassium... 

The salts formed in the three reactions above are called sodium ethanoate, magnesium ethanoate and potassium ethanoate, respectively. 

CHjCOCOOH. A colourless liquid with an odour resembling that of ethanoic acid, m.p. 13 C, b.p. 65 C/lOmm. It is an intermediate in the breakdown of sugars to alcohol by yeast. Prepared by distilling tartaric acid with potassium hydrogen sulphate. Tends 10 polymerize to a solid (m.p. 92 C). Oxidized to oxalic acid or ethanoic acid. Reduced to ( + )-Iactic acid. 

Addition of excess potassium nitrite acidified with ethanoic acid gives a precipitate of the potassium hexanitro-cobaltate(lll), K3[Co(N02)6] (P. 403). 

Chloroquinoline (401) reacts well with potassium fluoride in dimethylsulfone while its monocyclic analog 2-chloropyridine does not. Greater reactivity of derivatives of the bicyclic azine is evident also from the kinetic data (Table X, p. 336). 2-Chloroquinoline is alkoxylated by brief heating with methanolic methoxide or ethano-lic potassium hydroxide and is converted in very high yield into the thioether by trituration with thiocresol (20°, few hrs). It also reacts with active methylene carbanions (45-100% yield). The less reactive 3-halogen can be replaced under vigorous conditions (160°, aqueous ammonia-copper sulfate), as used for 3-bromoquino-line or its iV-oxide. 4-Chloroquinoline (406) is substituted by alcoholic hydrazine hydrate (80°, < 8 hr, 20% yield) and by methanolic methoxide (140°, < 3 hr, > 90% yield). This apparent reversal of the relative reactivity does not appear to be reliable in the face of the kinetic data (Tables X and XI, pp. 336 and 338) and the other qualitative comparisons presented here. 

A weighed amount of sample is dissolved in a mixture of propanone and ethanoic acid and titrated potentiometrically with standard lead nitrate solution, using glass and platinum electrodes in combination with a ferro-ferricyanide redox indicator system consisting of 1 mg lead ferrocyanide and 0.5 ml 10% potassium ferricyanide solution. The endpoint of the titration is located by graphical extrapolation of two branches of the titration plot. A standard solution of sodium sulfate is titrated in the same way and the sodium sulfate content is calculated from the amounts of titrant used for sample and standard. (d) Water. Two methods are currently available for the determination of water. 

Figure 2.1(A) shows raw fruit. The crisp, sharp-tasting fruit hecomes soft and sweet when it is cooked. Figure 2.1(B) shows a chemist accelerating the tranformation of ethanol into ethanoic acid, hy adding potassium dichromate and sulfuric acid.

Examples of salts from weak acids and strong bases include sodium ethanoate and potassium carbonate. 

Potassium standard solutions, 100 and 0-10 pg K+ mh - pipette 10 ml of the stock solution into a 100-ml volumetric flask and dilute with M ammonium ethanoate reagent to the mark and mix to give a solution of 100 pg K+ ml k Pipette 0, 2, 4, 6, 8 and 10 ml of this solution into 100-ml volumetric flasks and dilute to the mark with M ammonium ethanoate reagent and mix. These will contain 0, 2, 4, 6, 8 and 10 pg K+ ml k... 

Ethanol can be oxidised to ethanoic acid (an organic acid also called acetic acid) by powerful oxidising agents, such as warm acidified potassium dichromate(vi), or potassium manganate(vu). 

During the reaction the orange colour of potassium dichromate(vi) changes to a dark green (Figure 15.5) as the ethanol is oxidised to ethanoic acid. 

Figure 15.5 Orange potassium dichromate(vi) slowly turns green as it oxidises ethanol to ethanoic acid. Potassium manganate(vn) turns from purple to colourless.

This double Claisen-Schmidt reaction takes place under the influence of ethano-lic potassium hydroxide (Expt 7.7) and presumably proceeds in the stepwise manner (cf. formulation in Section 6.12.2, p. 1032). The four aryl groups in tetra-cyclopentadienone effectively stabilise the cyclopentadienone system, which otherwise has only a transient existence and readily undergoes dimerisation by way of a diene-dienophile interaction (Diels-Alder reaction, Section 7.6). The use of tetracyclone as a dienophile for the preparation of 3,4,5,6-tetraphenyl-dihydrophthalic anhydride is noted on p. 1121. 

Eschenmoser s pyrone 38 on treatment with cyclopropenone ketal 39 in refluxing benzene afforded lactone 40 (73%). Lactone 40 on hydrolysis with acetic acid at 100°C afforded, after deprotection and decarboxylation, tropone 37 (70%). Introduction of the tropolonic hydroxyl group was achieved with hydrazine hydrate in ethanol, to give a mixture of deacetyl-colchiceinamides 41 (53%) and 42 (37%), followed by reaction with ethano-lic potassium hydroxide, which afforded tropolones 43 and 44, respectively. Tropolone 43 was converted to 44 which, therefore, became the major reaction product. Methylation of 44 gave a mixture of enol ether 18 and 45 which were separated by chromatography. 

Acidified potassium dichromatc(VI) was used to oxidise ethanol to ethanoic acid using the apparatus in the diagram. 

When the reactants and the catalyst are in the same physical state the catalyst is called a homogeneous catalyst e.g. concentrated sulfuric acid speeds up the reaction between ethanoic acid and ethanol to form the ester, ethyl ethanoate. Manganese(IV) oxide catalyses the thermal decomposition of potassium chlorate(V) to give oxygen. 

Kolbe described the product derived from the electrolysis of potassium acetate (ethanoate) as a methyl radical with the formula C2H3. We now know that the product is ethane (C2H6), which is actually a product of dimerization of two methyl radicals ( CH3).6... 

To a three-necked round-bottomed flask (1 L) equipped with a reflux condenser, thermometer, a dropping funnel (250 mL), and a magnetic stirrer bar, add dimethylformamide (300 mL) and anhydrous potassium carbonate (69.1 g, 0.5 mol). Using a powder funnel, add methyl p-hydroxybenzoate (60 g, 0.40 mol) together with the potassium iodide. Heat the solution to 90°C and add 6-chlorohexyl ethanoate (97.4 g, 0.54 mol) drop-wise over several hours. Stir the solution for a total of 24 h whereupon TLC (silica gel, 3 2 petroleum ether ethyl acetate) should indicate the complete conversion of starting material. 

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