Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Ethylene glycol, sodium reaction

A valuable route to benzofurazans is provided by deoxygenation of the corresponding benzofuroxan. This may be accomplished either directly using trialkyl phosphites, tributyl-or triphe nyl-phosphine, or indirectly via the quinone dioxime using, for example, methanol and potassium hydroxide, hydroxylamine and alkali, sodium azide in DMSO or ethylene glycol, sodium borohydride, and occasionally thermolysis alone. More detailed discussion of these reactions is included in Section 4.22.3.2.4. [Pg.419]

Other bases may be employed, e.g. lithium hydride, sodium hydride, sodium amide or sodium in ethylene glycol with sodium in ethylene glycol, the reaction is called the Bamford-Stevens reaction. Aldehyde tosylhydrazones (200) do not form dianions with organolithiums, but the reagent adds to the carbon-nitrogen double bond to give the dilithium derivative (201) which decomposes to the organolithium compound (202). [Pg.218]

Displacement of Cl or Br. Bunnett and Conner improved a previous procedure for the preparation of 2,4-dinitroiodobenzene from the chloro compound by using dimethylformamide as solvent in place of ethylene glycol. Sodium iodide was taken in fivefold molar excess, presumably on the ground that the reaction is reversible. [Pg.1277]

The base-mediated conversion of arylsulfonylhydrazones to alkenes was first observed by Bamford and Stevens in 1952.6 In a representative transformation, tosylhydrazone 3 was converted to cyclohexene (4) in quantitative yield after refluxing for 90 minutes in an alkoxide solution derived from dissolution of sodium in ethylene glycol. These reactions are believed to proceed via intermediate diazo compounds, which are transformed to alkenes by thermal elimination processes. [Pg.405]

Reaction by-products include poly(ethylene oxide) and ethylene glycol. Sodium hydroxide is not consumed. [Pg.49]

A provocative reaction of ethylene glycol direcdy with siUcon dioxide that leads to a complex mixture of oligomeric and cycHc ester species has been reported (32). This reaction proceeds in the presence of sodium hydroxide or in the presence of high boiling tertiary amines (33). [Pg.39]

The addition product, C QHgNa, called naphthalenesodium or sodium naphthalene complex, may be regarded as a resonance hybrid. The ether is more than just a solvent that promotes the reaction. StabiUty of the complex depends on the presence of the ether, and sodium can be Hberated by evaporating the ether or by dilution using an indifferent solvent, such as ethyl ether. A number of ether-type solvents are effective in complex preparation, such as methyl ethyl ether, ethylene glycol dimethyl ether, dioxane, and THF. Trimethyl amine also promotes complex formation. This reaction proceeds with all alkah metals. Other aromatic compounds, eg, diphenyl, anthracene, and phenanthrene, also form sodium complexes (16,20). [Pg.163]

With Phenols. The 2-hydroxylethyl aryl ethers are prepared from the reaction of ethylene oxide with phenols at elevated temperatures and pressures (78,79). 2-Phenoxyethyl alcohol is a perfume fixative. The water-soluble alkylphenol ethers of the higher poly(ethylene glycol)s are important surface-active agents. They are made by adding ethylene oxide to the alkylphenol at ca 200°C and 200—250 kPa (>2 atm), using sodium acetate or... [Pg.453]

In 1928 J. C. Patrick attempted to produce ethylene glycol by reacting ethylene dichloride with sodium polysulphide. In fact a rubbery polymer was formed by the reaction ... [Pg.551]

Dinitroiodobenzene has been prepared by the nitration of 0- or /)-nitroiodobenzene, by treatment of 2,4-dinitrobenzenedi-azonium sulfate with potassium iodide, and by the reaction of sodium iodide with 2,4-dinitrochlorobenzene in refluxing ethylene glycol. The present procedure is a modification of the last-mentioned one. [Pg.36]

For unsubstitUted or lower alkylated dioxotriazines, it is advantageous to cyclize semicarbazones by sodium ethylate in ethylene glycol as described by Chang and XJlbricht. In this reaction 6-aza-uracil is obtained in 66% yield. The procedure was used for the preparation of labeled 6-azauracil ° and later for the synthesis of a number of 6-alkyl derivatives including 6-azathymine. °... [Pg.206]

Of greater versatility is an extension of Albert and Royer s acridine synthesis. The first successful use of this in the quinazoline series was for the removal of the chlorine atom in 2-chloro-4-phenylquin-azoline, although it had been used previously to prepare 8-nitro-6-methoxyquinazoline in very poor yield. The 4-chloroquinazoline is converted to its 4-(A -toluene-p-sulfonylhydrazino) quinazoline hydrochloride derivative which is decomposed with alkali in aqueous ethylene glycol at lOO C (Scheme 13). The yields are high (60-70%) when R is Me, Cl, OMe but low when R is NO2, and in the latter case it is preferable to use dilute sodium carbonate as the base. This reaction is unsatisfactory if the unsubstituted pyrimidine ring is unstable towards alkali, as in 1,3,8-triazanaphthalene where the pyrimi-... [Pg.299]

A mixture of cyclohexanone (11.8 g, 0.12 mole), ethylene glycol (8.2 g, 0.13 mole), /j-toluenesulfonic acid monohydrate (0.05 g), and 50 ml of benzene is placed in a 250-ml round-bottom flask fitted with a water separator and a condenser (drying tube). The flask is refluxed (mantle) until the theoretical amount of water (approx. 2.2 ml) has collected in the separator trap. The cooled reaction mixture is washed with 20 ml of 10 % sodium hydroxide solution followed by five 10-ml washes with water, dried over anhydrous potassium carbonate, and filtered. The benzene is removed (rotary evaporator) and the residue is distilled, affording l,4-dioxaspiro[4.5]decane, bp 65-67713 mm, 1.4565-1.4575, in about 80% yield. [Pg.64]

Scheme 3b). It is instructive at this point to reiterate that the furan nucleus can be used in synthesis as a progenitor for a 1,4-dicarbonyl. Whereas the action of aqueous acid on a furan is known to provide direct access to a 1,4-dicarbonyl compound, exposure of a furan to an alcohol and an acid catalyst should result in the formation of a 1,4-diketal. Indeed, when a solution of intermediate 15 in benzene is treated with excess ethylene glycol, a catalytic amount of / ara-toluenesulfonic acid, and a trace of hydroquinone at reflux, bisethylene ketal 14 is formed in a yield of 71 %. The azeotropic removal of water provides a driving force for the ketalization reaction, and the presence of a trace of hydroquinone suppresses the formation of polymeric material. Through a Finkelstein reaction,14 the action of sodium iodide on primary bromide 14 results in the formation of primary iodide 23, a substance which is then treated, in crude form, with triphenylphosphine to give crystalline phosphonium iodide 24 in a yield of 93 % from 14. Scheme 3b). It is instructive at this point to reiterate that the furan nucleus can be used in synthesis as a progenitor for a 1,4-dicarbonyl. Whereas the action of aqueous acid on a furan is known to provide direct access to a 1,4-dicarbonyl compound, exposure of a furan to an alcohol and an acid catalyst should result in the formation of a 1,4-diketal. Indeed, when a solution of intermediate 15 in benzene is treated with excess ethylene glycol, a catalytic amount of / ara-toluenesulfonic acid, and a trace of hydroquinone at reflux, bisethylene ketal 14 is formed in a yield of 71 %. The azeotropic removal of water provides a driving force for the ketalization reaction, and the presence of a trace of hydroquinone suppresses the formation of polymeric material. Through a Finkelstein reaction,14 the action of sodium iodide on primary bromide 14 results in the formation of primary iodide 23, a substance which is then treated, in crude form, with triphenylphosphine to give crystalline phosphonium iodide 24 in a yield of 93 % from 14.
Aqueous solutions of many salts, of the common strong acids (hydrochloric, nitric and sulphuric), and of bases such as sodium hydroxide and potassium hydroxide are good conductors of electricity, whereas pure water shows only a very poor conducting capability. The above solutes are therefore termed electrolytes. On the other hand, certain solutes, for example ethane-1,2-diol (ethylene glycol) which is used as antifreeze , produce solutions which show a conducting capability only little different from that of water such solutes are referred to as non-electrolytes. Most reactions of analytical importance occurring in aqueous solution involve electrolytes, and it is necessary to consider the nature of such solutions. [Pg.19]

Extension of these studies to formic acid media (containing 4 vol. % ethylene glycol and 1.3 vol. % water) showed that for protodeboronation of 4-methoxy-benzeneboronic acid at 25 °C) rates were invariant of a tenfold variation in acidity produced by adding sodium formate (0.05-0.20 M) to the medium (Table 194), and in this range the concentration of molecular formic acid is essentially constant. This was, therefore, assumed to be the reactive species. At higher acidities the rate increased, which was attributed to the increase in concentration of hydronium ions and protonated formic acid ions which bring about reaction more readily625. [Pg.291]

Example 2. Reactor Experiment.66 Waste PET (110 g), 800 g of ethylene glycol, and 93 g of 50% aqueous sodium hydroxide were introduced into a reactor. The reaction mixture was heated to 170° C with agitation while collecting distillate (mostly water with some ethylene glycol). The slurry, which consisted of disodium terephthalate in ethylene glycol, was filtered at a temperature of 170° C in a vacuum filter. The disodium terephthalate obtained was pressed as dry as possible and the ethylene glycol was recovered. The filter cake was washed with room temperature EG to remove impurities and to cool the disodium terephthalate to less than 100° C, followed by washing with a saturated solution of disodium terephthalate in water (maintained at 90-100° C). [Pg.560]

A method of converting polycarbonate (PC) to bishydroxyethyl ether of bisphenol A (BHE-BPA) was studied, with a view to recycling PC plastic wastes. Treating PC in ethylene glycol with a catalytic amount of sodium hydroxide produced the monohydroxyethyl ether of bisphenol A (MHE-BPA, 42%), BHE-BPA (11%) and BPA (42%). BHE-BPA was produced quantitatively when 1.6 mol. equiv. ethylene carbonate was added to this reaction system. The reaction of BPA with EC produced both BHE-BPA and MHE-BPA, indicating that ethylene carbonate was formed as an intermediate in the base catalysed reaction of PC with ethylene glycol. A large proportion of this ethylene carbonate formed from PC was, however, lost by decarboxylation so additional ethylene carbonate must be provided for the quantitative preparation of BHE-BPA. 12 refs. [Pg.42]

Polyphosphazenes sulfonates XIX with the anion covalently attached to the polymer are a new class of cation conductors that have been synthesized by Shriver [625]. They were obtained by reaction of Na0C2H4S03Na with an excess of polydichlorophosphazene in the presence of 15-crown-5, followed by the reaction of the partially substituted product with the sodium salt of poly(ethylene glycol methyl ether). The conductivity at 80 °C of the polymer with x=1.8, m=7.22 is 1.7x10 S cm This low conductivity can be attributed to an extensive ion pair formation between the sodium and sulfonate ions. [Pg.212]

P 20] The reaction was carried out using ethylene glycol/water (60 40 wt.-%) and hydrogen [63, 66]. To stabilize the gas/liquid interface, sodium dodecyl sulfate was added as surfactant. By this means, a foam stable for at least 6 min at 60 °C was achieved. Bubbles of a typical size of 200 pm were formed. The liquid content in the foam amounted to 20%. [Pg.633]

Ethylene glycol reacts dangerously with sodium hydroxide at a temperature starting at 230°C a highly exothermic decomposition, which emits a lot of hydrogen occurs. If the reaction takes place in a closed reactor, the apparatus detonates systematically. [Pg.249]


See other pages where Ethylene glycol, sodium reaction is mentioned: [Pg.403]    [Pg.449]    [Pg.93]    [Pg.74]    [Pg.86]    [Pg.308]    [Pg.49]    [Pg.87]    [Pg.100]    [Pg.98]    [Pg.101]    [Pg.103]    [Pg.23]    [Pg.112]    [Pg.41]    [Pg.170]    [Pg.542]    [Pg.953]    [Pg.543]    [Pg.545]    [Pg.547]    [Pg.560]    [Pg.85]    [Pg.466]    [Pg.32]    [Pg.267]    [Pg.953]   
See also in sourсe #XX -- [ Pg.248 ]




SEARCH



Ethylene glycol reactions

Ethylene reactions

Glycols reactions

Sodium ethylene glycolate

Sodium glycollate

© 2024 chempedia.info