Substitutions potassium acetate

Glycol.— This synthesis of di-hydroxy ethane was discovered by Wurtz, in 1854. The compound was named by him, glycol, because of its sweet taste. It is known also as ethylene glycol. The synthesis may be modified by substituting potassium acetate for the silver salt. Also, ethylene bromide is converted directly into the di-hydroxy compound, by boiling with dilute potassium carbonate. 

Halogen exchange with KF is not successful ia acetic acid (10). Hydrogen bonding of the acid hydrogen with the fluoride ion was postulated to cause acetate substitution for the haUde however, the products of dissolved KF ia acetic acid are potassium acetate and potassium bifluoride (11). Thus KF acts as a base rather than as a fluorinating agent ia acetic acid. 

Cellulose dissolved in suitable solvents, however, can be acetylated in a totally homogeneous manner, and several such methods have been suggested. Treatment in dimethyl sulfoxide (DMSO) with paraformaldehyde gives a soluble methylol derivative that reacts with glacial acetic acid, acetic anhydride, or acetyl chloride to form the acetate (63). The maximum degree of substitution obtained by this method is 2.0 some oxidation also occurs. Similarly, cellulose can be acetylated in solution with dimethylacetamide—paraformaldehyde and dimethylformamide-paraformaldehyde with a potassium acetate catalyst (64) to provide an almost quantitative yield of hydroxymethylceUulose acetate. 

Quinoxalin-2-one is a very weak base (pK — 1.37) and so the different orientation of substitution in acetic and sulfuric acids may mean that in acetic acid the principal species undergoing nitration is the neutral molecule, and in sulfuric acid, the mono-cation. Treatment of quinoxaline-2,3-dione, or its iViV -dimethyl derivative in sulfuric acid, with 1 equivalent of potassium nitrate, results in nitration at position 6 with 2 equivalents of potassium nitrate, 6,7-dinitro compounds are formed. When quinoxaline is boiled with aqueous nitric acid, 6-... 

It may not be appropriate to compare the thermal stability characteristics of VC/VAc copolymer to that of a VC homopolymer (PVC). The copolymerization would involve different kinetics and mechanism as compared to homopolymerization resulting structurally in quite different polymers. Hence, copolymerization of VC with VAc cannot be regarded as a substitution of chlorines in PVC by acetate groups. To eliminate the possibility of these differences Naqvi [45] substituted chlorines in PVC by acetate groups, using crown ethers (18-crown-6) to solubilize potassium acetate in organic solvents, and studied the thermal stability of the modified PVC. Following is the mechanism of the substitution reaction ... 

In onshore drilling there is no need for chlorides above these background levels. Potassium chloride has been added to some drilling fluids as an aid to controlling problem shale formations drilled. Potassium acetate or potassium carbonate are acceptable substitutes in most of these situations. 

In the context of this section it is important that Ruchardt and Tan (1970 a) found that (solid) benzenediazonium fluoroborate gave benzyne adducts with potassium acetate in the presence of aryne trapping agents such as tetracyclone or anthracene. This is, however, not the case if water is present (Cadogan, 1971). As a consequence of these observations, Cadogan et al. (1971) simplified the formation of arynes from diazonium ions by converting aniline or its substitution products into arynes in a... 

As previously discussed, solvents that dissolve cellulose by derivatization may be employed for further functionahzation, e.g., esterification. Thus, cellulose has been dissolved in paraformaldehyde/DMSO and esterified, e.g., by acetic, butyric, and phthalic anhydride, as well as by unsaturated methacrylic and maleic anhydride, in the presence of pyridine, or an acetate catalyst. DS values from 0.2 to 2.0 were obtained, being higher, 2.5 for cellulose acetate. H and NMR spectroscopy have indicated that the hydroxyl group of the methy-lol chains are preferably esterified with the anhydrides. Treatment of celliflose with this solvent system, at 90 °C, with methylene diacetate or ethylene diacetate, in the presence of potassium acetate, led to cellulose acetate with a DS of 1.5. Interestingly, the reaction with acetyl chloride or activated acid is less convenient DMAc or DMF can be substituted for DMSO [215-219]. In another set of experiments, polymer with high o -celliflose content was esterified with trimethylacetic anhydride, 1,2,4-benzenetricarboylic anhydride, trimellitic anhydride, phthalic anhydride, and a pyridine catalyst. The esters were isolated after 8h of reaction at 80-100°C, or Ih at room temperature (trimellitic anhydride). These are versatile compounds with interesting elastomeric and thermoplastic properties, and can be cast as films and membranes [220]. 

The procedure described here is based on a method outlined in U. S. patent 2,444,536.2 N-Phenylmaleimide has also been prepared by the dry distillation of the aniline salt of malic acid, 4 by treating the aniline salt of malic acid with phosphorus pent-oxide,5 and by treating maleanilic acid with phosphorus trichloride or with phosphorus pentoxide.5 Ring-substituted N-phenylmaleimides, viz., N-(/>-methoxyphenyl)-, N-(p-ethoxy-phenyl)-, and N-(/>-nitrophenyl)maleimide, have been prepared by treatment of the appropriate maleanilic acids with acetic anhydride and fused potassium acetate.7... 

Hydroxymethyl polystyrene has been prepared from chloromethyl polystyrene, either by conversion into the acetate by nucleophilic substitution followed by saponification, or directly by treatment with a mixture of potassium acetate and tetrabutyl-ammonium hydroxide in 1,2-dichlorobenzene/water (85 °C, 2 d [61]). 

Electrochemical oxidation of pentafluoroaniline (1) at a platinum anode at a potential of +1.5 to 1.6 V (vs SCE) using an acctonc/water/potassium acetate electrolyte leads to decafluoro-diphenyldiazene (3) and octafluorophenazine (2) in 18% and 6% yield, respectively. The phenazine heterocycle is formed by a sequence of oxidation/substitution steps in which nitrogen radical intermediates substitute fluorine atoms. The low yield in this reaction is due to a laborious workup.203 204... 

Gomberg-Bachmann biphenyl synthesis. Reaction of stable arenediazonium tet-rafluoroborates or hexafluorophosphates in an aromatic solvent with potassium acetate (2 equiv.) and a phase-transfer catalyst results in biar Is in high yield. Crown ethers, Aliquat 336, and tetrabutylammonium hydrogen sulfate arc all effective catalysts. The reaction is useful for synthesis of unsymmetrical biaryls. The ortho-isomer predominates in reactions with a monosubstituted benzene. The most selective method is to couple a substituted arenediazonium salt with a symmetrical arene. 

A certain double substitution reaction produced sUver chloride and potassium acetate. What were the reactants ... 

Although it is known that a chlorine atom at the 4-(or 5-)position is more reactive than at the 3- or 6-position for nucleophilic substitution, 3-acetamido-(or amino-)5-chloro-6-methoxypyridazine is resistant to hot aqueous sodium hydroxide and 30% sodium hydrogen sulfide solution, but susceptible to solvolysis in acetic acid containing anhydrous potassium acetate to yield the 5-hydroxy derivative. 

The retention times are 8.2 min for [Cl-(CH2)3]g(SiOi 5)5, 16.0 min for [Cl-(CH2)3],o(SiOi 5)10 and 37.4 min for [Cl-(CH2)3]i2(SiOi 5)12 at 7 mL min flow rate. The substitution of the chlorine atoms at octa [(3-chloropropyl)-silsesquioxane] by acetoxy- or cyano groups is possible by using potassium acetate or sodium cyanide and 18-crown-6 as phase transfer catalyst in acetonitrile. In addition to the observed substitution, partial rearrangement to the greater deca- and dodeca-silsesquioxane cages, also took place. 

The reaction is usually carried out be heating equimolar quantities of the aldehyde and salt with excess of the anhydride for 8 hours at 170-180°. Lower temperatures are often employed when potassium acetate or trialkylamines are used as condensing agents. Continuous removal of acetic acid during the reaction was found to have no effect on the yield of cinnamic acid. Substitution of diacetimide for acetic anhydride gives cinnamide (77%). ... 

The systematic study of nucleophilic substitutions of steroid alcohols and halides, pursued by Shoppee since 1946 [47], has yielded many examples of reactions which proceed with stereochemical inversion (Walden Inversion) [48] at the reaction centre. Acetolysis of the epimeric 3-chloro-5a- [4 ] and 3-chloro-5/ -cholestanes [4g] with potassium acetate in acetic acid gives 3-acetoxy derivatives of inverted configurations (Fig. 14) cholestenes, derived by elimination reactions, are... 

If 3jS tosyloxy-As steroids are solvolysed in weakly basic buffered media e.g. potassium acetate in aqueous acetone or in methanol) under mild conditions, the usual products are 6 substituted 3,5-cyclo-steroids (3), commonly referred to as "i-steroids . These are derived by nucleophilic attack of solvent or an anion upon the 6/5-position in the mesomeric cation 2). The theoretical significance and practical utility of this reaction have been studied intensively since its discovery by Stoll in 1932, and the present survey collects results of mechanistic importance from some eighty papers bearing on the subject. 

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