Fittig synthesis

IV,1. n-Butylberkzene Wurtz - Fittig synthesis) IV,2. i o-Propylbenzene (cumene)... 

Ullmann reaction org chem A variation of the Fittig synthesis, using copper powder instead of sodium. ol-mon re,ak-sh3n ... 

The Vuitz or Wnrtz-Fittig synthesis is usually thought of as a coupling reaction of two molecules of a halide or different halides by metallic sodium. In the liquid phase, as the reaction is generally carried out, alkylsodium compounds are intermediates and the coupling stage or second step is comparable to the reactions discussed above. °... 

Perkin-Fittig Synthesis.—The first step in the synthesis is analogous to the aldol condensation. It consists in the addition of a sodium salt of an acid, usually acetic acid, to a saturated aldehyde, whereby condensation is effected and a > /a-hydroxy acid is formed. The beta-... 

This is the simplest case of the reaction but it has been mostly used in the synthesis of higher members of the unsaturated acid series, e.g., the nine carbon acid, nonylenic acid, which is prepared from the seven carbon aldehyde known as oenanthylic aldehyde, or oenanthol, obtained from castor oil. Even more important than its application in the synthesis of higher acids of the ethylene series is the use of the reaction in the synthesis of aromatic unsaturated cLcids derived from benzene and containing an unsaturated side chain (see cinnamic acid. Part II). The reaction is known as the Perkin Synthesis or as the Perkin-Fittig Synthesis from the men who suggested and explained it. 

From Acetaldehyde and Malonic Acid.—Another synthesis proves the constitution of crotonic acid as A2-butenoic acid. A di-basic acid known as malonic acid has the constitution of di-carhoxy methane HOOC—CH2—COOH. When this acid is heated with acetaldehyde (paraldehyde) and glacial acetic acid condensation occurs as in the synthesis of crotonic aldehyde and in the Perkin-Fittig synthesis (p. 172). A dibasic acid is obtained which loses carbon dioxide and yields a mono-basic acid which is crotonic acid. 

Fittig s Synthesis.—When Kekule brought out his benzene theory the relation between toluene and benzene, the first two members of the homologous series of benzene hydrocarbons, was not known. It was worked out by Fittig and Tollens by means of what is known as the Fittig synthesis, which is based on a reaction exactly analogous to the Wurtz reaction for the synthesis of the homologous members of the aliphatic series of hydrocarbons. 

Ullman reaction. Synthesis of biaryls by copper-induced coupling of aryl halides. Similar coupling of aryl halides with aroxides yields diaryl ethers. (A modification of the Fittig synthesis in which copper powder is used instead of sodium.)... 

NOTE.—(a) In the preparation of hydrocarbons by the Fittig synthesis the halides used are often diluted with ether in order to moderate the reaction the volume of ether used ordinarily is twice that of the halogen compounds. Benzene and petroleum ether are also used as diluents, especially in the ease of very active substances, when it is desired to have the reaction take place very slowly. When reaction takes place sluggishly, the mixture without diluents can be heated on a water-bath or in an oil-bath. The reaction between halides and sodium is catalyzed by a few drops of ethyl acetate or methyl cyanide. 

Although the classical Wurtz-Fittig synthesis has been widely replaced by procedures using milder reaction conditions (see following chapters), alkali metals like potassium in dimethoxyethane (DME) have been used in the dimerization of 1,1 binaphthyls (e.g. 47, see Scheme 21) to perylene derivatives (e.g. 

Fittig (Fittig synthesis) discovered that aromatic and aliphatic aldehydes (i.e., 1) react readily with sodium succinate 23 and acetic anhydride at 100 °C, to give y-phenyl and y-alkyl paraconic acid (i.e., 24) in satisfactory yield. The acid loses carbon dioxide upon heating to form a p,y-unsaturated acid 25.2... 

When an organolithium compound reacts with an organic halide the product is usually a hydrocarbon, reaction being analogous to a Wurtz-Fittig synthesis. However, the action of alkyl- or aryl-lithiums replaces the halogen by lithium in several halogenated heterocycles, aromatic ethers, and alkyl... 

Condensation of tin tetrachloride and organic halides by means of metallic sodium,423-425 analogous to a Wurtz-Fittig synthesis, is very widely applicable to synthesis of tetraalkyl- and tetraaryl-tins ... 

Two or more benzene rings can be united by the application of the Fittig synthesis. Bromobenzene and sodium yield diphenyl —... 

Other methods of preparation analogous to the Fittig synthesis are frequently used. In the case of certain compounds the halogen atoms are more readily removed by zinc or silver. Tetraphenylethane is conveniently prepared by treating a solution of diphenylbromomethane with zinc —... 

The need for a thermally stable, solvent-resistant polymer was met by the use of a Wurtz-Fittig synthesis of polyphenylene sulfide. The need for an impact-resistant clear polymer was fulfilled by the reaction of phosgene and the sodium salt of bisphenol A. Admittedly, polymers of formaldehyde, which are found as a sediment in formalin bottles, was investigated by Nobel Laurate Hermann Staudinger in the 1920 s but this polymer lacked integrity until DuPont and Celanese chemists produced thermally stable, injection moldable polyoxymethylene. 

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