Benzoyl chloride, Friedel-Crafts reaction

Prepared by the dehydration of benzamide. Hydrolysed by dilute acids and alkalis to benzoic acid. Good solvent. benzopheDone,C]3HioO,PhC(0)Ph. Colourless rhombic prisms, m.p. 49 C, b.p. 306°C. Characteristic smell. It is prepared by the action of benzoyl chloride upon benzene in the presence of aluminium chloride (Friedel-Crafts reaction) or by the oxidation of di-phenylmethane. It is much used in perfumery. Forms a kelyl with sodium. 

Two diphenylaminophthalides have been synthesized The 3,3-diphenyl-6-aminophthalide [24] was synthesized in 20% yield by the following sequence of reactions which was patterned after early work °. This series involved nitration of phthalimide, hydrolysis and dehydration to 4-nitrophthalic anhydride, Friedel-Crafts reaction with benzene to 2-benzoyl-5-nitrobenzoic acid, cyclization with thionyl chloride to the pseudoacid chloride, Friedel-Crafts reactions with benzene, and, finally reduction of the nitro group to the amino function with Adams catalyst. 

Benzophenone is produced by the oxidation of diphenylmethane (350). This free from chlorine (FCC) route is favored for perfume uses. The Friedel-Crafts reaction of benzene and benzoyl chloride in the presence of aluminum chloride is also possible this reaction may proceed in the absence of catalyst at a temperature of 370°C and pressure of 1.4 MPa (351). 

Benzoyl chloride is an important benzoylating agent. In this use the benzoyl radical is introduced into alcohols, phenols, amines, and other compounds through the Friedel-Crafts reaction and the Schotten-Baumaim reaction. Other significant uses are in the production of benzoyl peroxide [94-56-0], benzophenone [119-61-9], and in derivatives employed in the fields of dyes, resins, perfumes, pharmaceuticals, and as polymerization catalysts. 

Olah et al. (1999) have been able to realize selective cyclisation of o-benzoyl benzoic acid to anthraquinone using dichlorobenzene as a solvent and Nafion-H as a catalyst. This may lead to avoidance of the Friedel-Crafts reaction using a stoichiometric amount of aluminium chloride and resulting in a lot of wa,ste. Many other examples of similar reactions have been reported. 

Friedel-Crafts reaction with benzoyl chloride... 

Sometimes acylium ions lose carbon monoxide to generate an ordinary carbonium ion. It will be recalled that free acyl radicals exhibit similar behavior at high temperatures. Whether or not the loss of carbon monoxide takes place seems to depend on the stability of the resulting carbonium ion and on the speed with which the acylium ion is removed by competing reactions. Thus no decarbonylation is observed in Friedel-Crafts reactions of benzoyl chloride, the phenyl cation being rather unstable. But attempts to make pivaloyl benzene by the Friedel-Crafts reaction produce tert-butyl benzene instead. With compound XLIV cyclization competes with decarbonylation, but this competition is not successful in the case of compound XLV in which the ring is deactivated.263... 

When (190) was subjected to a Friedel-Crafts reaction with benzoyl chloride, the result was an analog of coralyne with a phenyl rather than a methyl group at position 8. Kametani et al. (74YZ478) have carried out a parallel study using the Vilsmeier-Haack reaction to produce norcoralyne. 

Rhodium acetylacetonate differed considerably from the other metal chelates in the acetylation reaction (26). Under the same conditions that had given extensive acetylation of the cobalt and chromium acetylacetonates, the rhodium chelate reacted very slowly and formed only a small amount of the monoacetylated compound (XX). Fortunately, the hydrolytic stability of rhodium acetylacetonate is such that the Friedel-Crafts reaction can be carried out under vigorous conditions that would rapidly degrade the chromium and cobalt chelates. Thus treatment of rhodium acetylacetonate with acetyl chloride and aluminum chloride in dichloroethane afforded the mono- and diacetylated chelates (XX and XXI). No triacetylated chelate was isolated from this reaction. In a similar manner butyryl-and benzoyl-substituted rhodium chelates (XXIII and XXIV) have been prepared. These and other experiments indicate that the rhodium acetylacetonate ring is less reactive than the cobalt or chromium rings. 

No examples have been found in which either an eight-membered ring or a four- or three-membered ring has been fbrmed by intramolecular acylation. The failure of phenylacetyl chloride and benzoyl chloride to cyclize under the conditions of the Friedel-Crafts reaction has been reported.12... 

The Friedel-Crafts reaction has limited application in pyrazole chemistry, as the acyl group can be introduced only in the 4-position. The reaction is easier with 1-arylpyrazoles which are less inclined to form pyrazole cations.822,828 Heating N-substituted pyrazoles with benzoyl chloride at 200-230° for some hours gives high yields of 4-benz-oylpyrazoles (60) even in the absence of catalysts.48,505,647,624,825... 

Benzylation of toluene with benzyl chloride, which is a typical example of Friedel-Crafts alkylation, is known to be catalyzed by Lewis-type superacids such as A1C13 and BF3. This type of catalyst has been mostly used for the Friedel-Crafts reaction, which is one of the most studied of organic reactions. This reaction was performed over several metal oxides and sulfates, and iron sulfates showed an unexpected effectiveness for the reaction (102-104). The catalytic activities of FeS04 and Fe2(S04)3 for the reaction were examined in detail the activities were remarkably dependent on calcination temperature, the maximum activity being observed with calcination at 700°C (105-107). Catalytic actions analogous to the above case were also observed with other Friedel-Crafts reactions, the benzoyl-ation of toluene with benzoyl chloride (108), the isopropylation of toluene with isopropyl halides (109), and the polycondensation of benzyl chloride UIO). 

For the preparation of unsymmetrical ferrocenes, two ways by which only mono-substituted derivatives are produced have been suggested. One route starts from iron tetracarbonyl and a substituted cyclopenta-diene the other from monocyclopentadienyl iron dicarbonyl bromide, which on treatment with a substituted cyclopentadienyl lithium is finally converted into the corresponding mono-substituted ferrocene. Experience shows the first method to be more suitable for the preparation of aryl, and the latter method for the preparation of alkyl, derivatives (57). Corresponding work already carried out on substitution in Ru(C5H6)2 and Os CsH5)2 has also been fruitful. It is found that in the Friedel-Crafts reaction with acetyl or benzoyl chloride there is a distinct predominance of mono- over disubstitution as the atomic weight of the central atom increases (47, 72). 

On oxidation with Cr03, the 2-carboxy-derivative is readily obtained, which can be converted with diazomethane into the methoxycarbonyl analogue. The carboxy-compound gives an acid chloride with PC15 and a benzoyl derivative on Friedel-Crafts reaction with benzene.92... 

In a brief preliminary note Heine, Cottle, and Van Mater reported comparative results showing that zirconium tetrachloride is generally superior to aluminum chloride for the Friedel-Crafts p-acetylation of toluene with acetyl chloride. However, the results were less consistent with ZrCl, than with AICI3. Gore and Hoskins studied the Friedel-Crafts reaction of benzoyl chloride with anthracene in ethylene dichloride at 0° in the presence of 14 different catalysts. The best yields of very pure 9-benzoylanthracene were with zirconium tetrachloride (97% yield after lihrs.) and with aluminum chloride (86% yield after U hrs., 99% yield after 99 hrs.). 

Friedel-Crafts reaction on a polymeric support (Scheme 132) [106] To a vial charged with AICI3 (253 mg, 1.9 mmol) and CH2CI2 (5 mL) was added benzoyl chloride (0.133 mL, 1.14 mmol). After agitation for 0.5 h at r. t., resin-bound indole (635) (312 mg, 0.32 mmol) was added in one portion. After agitation for 12 h at r.t., the resin was washed as follows ... 

C13H10O, Mt 182.22, bp(,3 kPa 200.5 °C, d50 1.976, has been identified as a flavor component of grapes. It is a colorless, crystalline solid (mp 48.1 °C) with a rosy, slightly geranium-like odor. It can be prepared in several ways, for example, by Friedel-Crafts reaction of benzene and benzoyl chloride with aluminum chloride, or of benzene and carbon tetrachloride, and subsequent hydrolysis of the resulting a,a-dichlorodiphenylmethane. Benzophenone can also be prepared by oxidation of diphenylmethane. It is used in flower compositions and as a fixative. 

Mekonnen and Crank also found the same reaction dichotomy in Friedel-Crafts reactions of 622 (X = O) with acid chlorides or acid anhydrides. In general, acylation of 622 (X = O, R = CH3) with acetic anhydride or benzoyl chloride/ pyridine afforded the corresponding 2-(acylamino)-4-methyloxazole 630a and 630b (Scheme 1.174). However, low-temperature acetylation or aroylation of 622 (X = O, R = CH3) in the presence of two equivalents of AICI3 produced a 5-acyl-2-amino-4-methyloxazole 631 in low to modest yield. The authors reported that AICI3 was the most effective Lewis acid (SnCLj and TiCL) and that the reaction required two equivalents of Lewis acid. Selected examples are shown in Table 1.48. 

Friedel-Crafts reaction of the benzoyl chloride (459) with thiophene (460) gave the ketone (461) which was deprotected and reduced to the amine... 

Benzophenone is obtained by the reaction of benzoyl chloride with benzene under Friedel-Crafts reaction conditions. Benzophenone is used as a perfume component and as an additive in the production of printing inks. 

Also obtained by Friedel-Crafts reaction between-benzoyl chloride and pyrocatechol dimethyl ether, followed by demethylation of the product so obtained [1505]. 

Friedel-Crafts Reactions. Aluminum trifluoromethanesulfonate has been used for the Friedel-Crafts alkylation reaction of toluene with isopropyl and tert-butyl chlorides (eq 1), and for the acylation of benzene and toluene with acetyl and benzoyl chlorides in low to moderate yields. Intramolecular Friedel-Crafts acylation of an aromatic compound with Meldrum s acid has also been reported using catalytic amounts of Al(OTf)3. Acylation of 2-methoxynaphthalene with acetic anhydride has been reported using Al(OTf)3 and lithium perchlorate as an additive to afford the corresponding 6-acetylated adduct in 83% yield. Effective acylation of arenes with carboxylic acids has also been disclosed using polystyrene-supported Al(OTf)3. ... 

Friedel-Crafts Acylation. The Friedel-Crafts acylation procedure is the most important method for preparing aromatic ketones and thein derivatives. Acetyl chloride (acetic anhydride) reacts with benzene ia the presence of aluminum chloride or acid catalysts to produce acetophenone [98-86-2], CgHgO (1-phenylethanone). Benzene can also be condensed with dicarboxyHc acid anhydrides to yield benzoyl derivatives of carboxyHc acids. These benzoyl derivatives are often used for constmcting polycycHc molecules (Haworth reaction). For example, benzene reacts with succinic anhydride ia the presence of aluminum chloride to produce P-benzoylpropionic acid [2051-95-8] which is converted iato a-tetralone [529-34-0] (30). 

An alternative route to anthraquinone, which involves Friedel-Crafts acylation, is illustrated in Scheme 4.3. This route uses benzene and phthalic anhydride as starting materials. In the presence of aluminium(m) chloride, a Lewis acid catalyst, these compounds react to form 2-benzoyl-benzene-1-carboxylic acid, 74. The intermediate 74 is then heated with concentrated sulfuric acid under which conditions cyclisation to anthraquinone 52 takes place. Both stages of this reaction sequence involve Friedel-Crafts acylation reactions. In the first stage the reaction is inter-molecular, while the second step in which cyclisation takes place, involves an intramolecular reaction. In contrast to the oxidation route, the Friedel-Crafts route offers considerable versatility. A range of substituted... 

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