Chlorobenzene, benzylation

Problem 11.44 Use + and - signs for positive and negative tests in tabulating rapid chemical reactions that an be used to distinguish among the following compounds (a) chlorobenzene, benzyl chloride and cyclohexyl hloride (b) ethylbenzene, styrene, and phenylacetylene. ... 

Reactions Chlorobenzene Benzyl chloride Cyclohexyl chloride... 

REACTIONS CHLOROBENZENE BENZYL CHLORIDE CYCLOHEXYL CHLORIDE... 

Methyl iodide, ethyl bromide and iodide, higher alpihatic halides chloroform, iodoform, carbon tetrachloride chlorobenzene, bromobenzene, iodobenzene benzyl chloride. 

Chlorobenzene, CjHjCl, bromobenzene, CgHgBr, and iodobenzene possess aromatic odours. Benzyl chloride, CgHjCHgCl, has a sharp irritating odour and is lachrymatory. 

The following liquids may be used (boiling points are given in parentheses) — chlorobenzene (132-3°) bromobenzene (155°) p cymene (176°) o-dichloro-benzene (180°) aniline (184°) methyl benzoate (200°) teti-alin (207°) ethyl benzoate (212°) 1 2 4-trichlorobenzene (213°) iaopropyl benzoate (218°) methyl salicylate (223°) n-propyl benzoate (231°) diethyleneglycol (244°) n-butyl benzoate (250°) diphenyl (255°) diphenyl ether (259°) dimethyl phth ate (282°) diethyl phthalate (296°) diphenylamine (302°) benzophenone (305)° benzyl benzoate (316°). 

The formation of alkylbenzenes, largely free from unaaturated compounds, provides another interesting application of organosodium compounds. Thus pure M-butylbenzene is readily obtained in good yield from benzyl sodium and n-propyl bromide. Benzyl-sodium is conveniently prepared by first forming phenyl-sodium by reaction between sodium and chlorobenzene in a toluene medium, followed by heating the toluene suspension of the phenyl-sodium at 105° for about 35 minutes ... 

Other sources of by-product HCl include allyl chloride, chlorobenzenes, chlorinated paraffins, linear alkylbenzene, siHcone fluids and elastomers, magnesium, fluoropolymers, chlorotoluenes, benzyl chloride, potassium sulfate, and agricultural chemicals. 

NOTE - Petrochemical plants also generate significant amounts of solid wastes and sludges, some of which may be considered hazardous because of the presence of toxic organics and heavy metals. Spent caustic and other hazardous wastes may be generated in significant quantities examples are distillation residues associated with units handling acetaldehyde, acetonitrile, benzyl chloride, carbon tetrachloride, cumene, phthallic anhydride, nitrobenzene, methyl ethyl pyridine, toluene diisocyanate, trichloroethane, trichloroethylene, perchloro-ethylene, aniline, chlorobenzenes, dimethyl hydrazine, ethylene dibromide, toluenediamine, epichlorohydrin, ethyl chloride, ethylene dichloride, and vinyl chloride. 

Amino-2-phenyl-2//-benzotriazole reacted with epichlorhydrin in chlorobenzene at 140-145°C to give the A-benzyl-7-hydroxy-6,7,8,9-tetrahydrotriazolo-quinoline derivative 194. This was benzylated and rearranged by heating in DMSO to give the isomeric 7-benzyloxy derivative 195 (Scheme 59) (77MI2). 

It has been found that aryl groups can also be introduced into the a-position of sulphoxides. Corey and Chaykovsky have demonstrated that chlorobenzene reacts at room temperature with an excess of sodium methylsulphinyl carbanion to give methyl benzyl sulphoxide in 41% yield. The authors believe that a benzyne intermediate may be involved in the reaction400,401 (equation 174). 

Poly(arylene ether ketone)s can also be modified by introducing the functional groups using similar approaches to polysulfones. For example, poly(arylene ether ketone)s were sulfonated.189 In addition, o-dibenzoylbenzene moieties in the poly(arylene ether)s can be transformed to heterocycles by cyclization with small molecules. These polymers can react with hydrazine monohydrate in the presence of a mild acid in chlorobenzene or with benzylamine in a basic medium.190 Another example of the use of the o-benzyl cyclization strategy is the intramolecular ring closure of poly(arylene ketone)s containing 2,2/-dibenzoylbiphenyl units to form poly(arylene ether phenanthrenes).191... 

Oxidation of benzene (and also chlorobenzene and toluene) by Mn(III) acetate in glacial acetic acid gives a mixture of products including benzyl acetate (from benzene) indicating an initial attack on the aromatic by CH2C02H . The kinetics and actual rate of disappearance of Mn(III) are the same for CgHs and... 

Sulphated zirconia catalysts can be acidic or superacidic depending on the method of treatment. A variety of acid-catalysed reactions, referred to earlier in this section, can be carried out with sulphated zirconia. Yadav and Nair (1999) have given a state-of-the art review on this subject. Examples of benzylation of benzene with benzyl chloride / benzyl alcohol, alkylation of o-xylene with. styrene, alkylation of diphenyl oxide with 1-dodecene, isomerization of epoxides to aldehydes, acylation of benzene / chlorobenzene with p-chloro benzoylchloride, etc. are covered in the review. 

Besides benzyl chloride, methyl- and/or chlorine-substituted benzyl chlorides, phenethyl chloride, etc. are also successfully employed to give 2 -diaralkylaminofluorans in excellent yield. However, aryl halides such as chlorobenzene and bromobenzene hardly enable the reaction, though aryl iodides such as iodobenzene give 2 -diarylaminofluorans in low yield. 

DMI) for the condensation of the m-hydroxy-benzyl alcohol (15) with chlorobenzene. 

In g/L Benzyl benzoate (420), carbon tetrachloride (450), chlorobenzene (740), cyclohexanone... 

Benzene bromide, see Bromobenzene Benzene carbinol, see Benzyl alcohol Benzenecarboxylic acid, see Benzoic acid Benzene chloride, see Chlorobenzene Benzene-1,4-diamine, see p-Phenylenediamine... 

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