Sodium phenoxide, alkylation

Dialkylaminoethyl acryhc esters are readily prepared by transesterification of the corresponding dialkylaminoethanol (102,103). Catalysts include strong acids and tetraalkyl titanates for higher alkyl esters and titanates, sodium phenoxides, magnesium alkoxides, and dialkyitin oxides, as well as titanium and zirconium chelates, for the preparation of functional esters. Because of loss of catalyst activity during the reaction, incremental or continuous additions may be required to maintain an adequate reaction rate. 

In an alternate synthesis of the intermediate ketone, the benzylic halide, 69, is used to alkylate sodium phenoxide. Cyclization of the acid (70) obtained on hydrolysis of the ester by means of trifluoroacetic anhydride again gives 67... 

Ethers can be prepared by reaction of an alkoxide or phenoxide ion with a primary alkyl halide. Anisole, for instance, results from reaction of sodium phenoxide with iodomethane. What kind of reaction is occurring Show the mechanism. 

Relative rates of reaction of alkyl bromides (in toluene) with aqueous sodium phenoxide under triphase conditions ... 

Although there have been few new developments in the period since 1993, halogenopyrazines 42 have been convenient precursors for a variety of pyrazine derivatives. For example, the halogenopyrazines 42 are cyanated by palladium-catalyzed cross-coupling with alkali cyanide or by treatment with copper cyanide in refluxing picoline, to yield cyanopyrazines 48. Alkoxypyrazines 49 are produced by treatment with alkoxide-alcohol, and aminopyrazines 50 are prepared by amination with ammonia or appropriate amines. The nucleophilic substitution of chloropyrazine with sodium alkoxide, phenoxide, alkyl- or arylthiolate is efficiently effected under focused microwave irradiation <2002T887>. 

The Williamson synthesis, using a sodium phenoxide and allyl bromide in methanol solution, is more rapid than the procedure using acetone and potassium carbonate and gives good results.16-36 441 66 Aqueous acetone also has been used as the reaction medium with allyl bromide and sodium hydroxide this method likewise is rapid and sometimes leads to better yields than the procedure using potassium carbonate and acetone.34 Allylation of 2-hydroxy-l,4-naphthoquinone has been carried out by treating the silver salt, in benzene, with allyl bromide 84 some C-alkylation as well as O-alkylation was observed. 

Answer Procedure XI1-6 which requires the use of a Uiazo-niuni salt and procedure VII-I, the Wiliiamsorysyntliesis which requires u sodium phenoxide and an alkyl liaiidc. 

Dialkoxyaldehydes of the type RCH(OCHj)CR(OCH,)CHO ate prepared from the corresponding a,/3-dichloroaldehydes by the action of very dilute solutions of sodium alkoxide below 15° (70-85%). In these preparations, the presence of potassium iodide or an alkyl iodide has been helpful. The yield of phenoxyacetone from chloroacetone and sodium phenoxide is increased from 16-23% to more than 90% chiefly by the presence of potassium iodide in the reaction mixture. The reaction of alkyl iodides with phenolic aldehydes in methanolic potassium hydroxide gives p-alkoxy-benzaldehydes (60-75%). ... 

Aromatic and aliphatic amino ethers have been synthesized by this method. An example of the formation of a cyano ether is the preparation of p-cyano benzyl methyl ether from the substituted benzyl bromide and sodium methoxide (84%). Also, certain aryloxyacetonitriles, AtOCHjCN, are made by the condensation of chloroacetonitrile with sodium phenoxides in a solution of methyl ethyl ketone containing a small amount of sodium iodide (70-80%). Aromatic nitro ethers, like o- and p-nitrodiphenyl ether, have been prepared by the Ullmann procedure (84%). The synthesis of alkyl p-nitrophenyl ethers has also been accomplished with good yields (55-92%). ... 

Pyridyl aryl or alkyl ethers are made by condensing 2-bromopyridine with the appropriate sodium phenoxide or sodium alkoxide, copper powder being an effective catalyst in certain instances. ... 

In the Williamson synthesis an alkyl halide (or substituted alkyl halide) is allowed to react with a sodium alkoxide or a sodium phenoxide ... 

It takes place at atmospheric pressme, in the presence of catalysts based on strong acids (sulfuric add) or alkyl titauates (teomsopropyl titan te) to obtain the higher acrylates, sodium phenoxides, magnesium or thaffium qjkoxides, alkyltin orides..etc. to. produce functional esters. 

Claisen had reported that the proportion of C- to O-alkylation could be greatly enhanced by the use of sodium phenoxides in benzene suspension and indeed this method has been beneficially employed for o-C-isoprenylation. In a general procedure (ref.9), an ethereal solution of the phenol (0.05 mole), was treated with metallic sodium (0.2 mole) and after 1.5 hours the prenyl chloride (RCI) was introduced. Upon refluxing for 10 hours, removal of excess sodium and acidic work-up, monohydric phenols afforded yields from 66-90%. For example, 2-methylphenolwith3-methylbuten-2-ylchloridegave2-methyl-6-(3-methylbuten-2-... 

Since the groups participating in the ether linkage are not identical, the ether to be synthesized is a-symmetrical. One method of producing asjTnmetrical ethers is through the Williamson synthesis. In this reaction, an alkyl halide (or substituted alkyl halide) is allowed to react with a sodium alkoxide or a sodium phenoxide as shown ... 

Acyl imidazoUdes. These compounds resemble acyl chlorides in reactivity and are thus useful in synthesis. Masamune has observed that they can be prepared by reaction of phenyl and 2,2,2-trifluoroethyl esters with N-(trimethyl-silyl)imidazole at 20° in the presence of a trace of sodium phenoxide (1). Alkyl... 

Other Methods of Alkylation. A useful method for the preparation of certain alkylated phenols is that devised by Claisen and extended by a number of investigators. The nuclear alkylation of phenols is accomplished by treating the sodium phenoxide with an active halide of... 

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