Friedel-Crafts reaction naphthalene

The commercial product, m.p. 53-55°, may be used. Alternatively the methyl -naphthyl ketone may be prepared from naphthalene as described in Section IV,136. The Friedel - Crafts reaction in nitrobenzene solution yields about 90 per cent, of the p-ketone and 10 per cent, of the a-ketone in carbon disulphide solution at — 15°, the proportions ore 65 per cent, of the a- and 35 per cent, of the p-isomer. With chlorobenzene ns the reaction medium, a high proportion of the a-ketone is also formed. Separation of the liquid a-isomer from the solid p-isomer in Such mixtures (which remain liquid at the ordinary temp>erature) is readily effected through the picrates the picrate of the liquid a-aceto compound is less soluble and the higher melting. 

Isopropylnaphthalenes produced by alkylation of naphthalene with propjdene have gained commercial importance as chemical intermediates, eg, 2-isopropylnaphthalene [2027-17-OJ, and as multipurpose solvents, eg, mixed isopropylnaphthalenes. Alkylation of naphthalene with alkyl haUdes (except methyl hahdes), acid chlorides, and acid anhydrides proceeds in the presence of anhydrous aluminum chloride by Friedel-Crafts reactions (qv). The products are alkylnaphthalenes or alkyl naphthyl ketones, respectively (see Alkylation). 

Typically in ring-opening reactions of aziridines, the amine functional group is retained in the product molecule. An example of such a reaction where the amine group has been lost has recently been reported <06TL977>. An intramolecular Friedel-Craft reaction of aziridine 91 leads to the expected product as an intermediate. Under the rather drastic reaction conditions, the sulfonamide is lost leading to formation of the naphthalene ring. 

The acid, referred to as tetra acid , is prepared as follows In a Friedel-Crafts reaction, acenaphthene 72 is reacted with malonic dinitrile and aluminum chloride. The resulting condensation product 75 is oxidized with sodium chlorate/hy-drochloric acid to form the dichloroacenaphthindandione 76. Oxidation with sodium hypochlorite solution/sodium permanganate affords naphthalene tetracar-boxylic acid 68, mostly existing as the monoanhydride 68a. The dianhydride, on the other hand, evolves only after drying at approx. 150°C. 

This procedure is based upon a study 1 of the method outlined in the patent literature.2 The procedure is a general one and may be used for the condensation of succinic anhydride with naphthalene and with the mono- and dimethylnaphthalenes, although in no other case are the purification and separation of isomers so easily accomplished. In this particular type of condensation, as well as in certain other types of Friedel-Crafts reactions, nitrobenzene is far superior to the solvents which are more frequently employed. This is partly because of its great solvent power and partly because it forms a molecular compound with aluminum chloride, and so decreases the activity of the catalyst in promoting side reactions. 

Under conditions of the Friedel-Crafts reaction, 1,5-naphthalene-bis-thioglycolic acid chloride forms a mixture of peri- and ortho-annelated isomers 309 and 310, with major predominance of the latter (49G286 ... 

Naphthalene is the simplest and most important of the fused ring hydrocarbons. Five percent of all constituents of coal tar are naphthalene. Naphthalene can be manufactured using the Friedel-Crafts reaction via the reaction pathway shown in Scheme I. 

Grignard reagent (see Chapter 10), followed by dehydration and arom-atization (Scheme 12.2). The use of substituted benzenes in the first stage of the sequence enables variously substituted derivatives of naphthalene to be obtained. Of course, the substituents should not interfere with the Friedel-Crafts reaction with succinic anhydride. 

Naphthalene, anthracene and phenantlirene can be prepared by an intramolecular Friedel-Crafts reaction in which initially a cyclic anhydride reacts with benzene or naphthalene. 

This test is given by any aromatic compound that can undergo the Friedel-Crafts reaction, with the particular color produced being characteristic of the aromatic system involved orange to red from halobenzenes, blue from naphthalene purple from phenanthrene, green from anthracene (Chap. 30). 

Shudo and coworkers have reported that 0,0-diprotonated nitroalkenes (16) behave as novel electrophilic species which can efficiently alkylate aromatics such as benzene, anisole, chlorobenzene, naphthalene, etc. under extremely mild conditions (equation 28). The reaction enables the synthesis of a-arylated ketones (17) which are difficult to synthesize by conventional Friedel-Crafts reactions. 

Chloroform is useful as solvent for Friedel-Crafts reactions not only because It dissolves the aluminum chloride-acetyl chloride complex but also because it hai an orienting effect. Thus the reaction of naphthalene with 2 equivalents each of... 

If one considers that in the modifications, in place of the hydrocarbons, ethers, mono- and poly-add phenols, naphthalene, thiophene, diphenyl,naphthol-ethers, and many other compounds can be used, the great value of the Friedel-Crafts reaction will be readily understood. 

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