With aromatic compounds

Tellurium tetrachloride readily reacts with aromatic compounds that contain substituents promoting electrophilic attack. Thus, heating an excess of methoxybenzene and tellurium tetrachloride at 180° leads to the formation of bi 4-methoxyphenyl] tellurium dichloride (Vol. IX, p. 1068). At lower temperatures, e.g., refluxing chloroform, only 4-methoxyphenyl tellurium trichloride is formed. This two-step reaction to diaryl tellurium dichlorides is promoted by elevated temperatures and the presence of an excess of the organic compound. 

Irgolic Organo Tellurium Compounds with 2 Te —C Bonds or 1 Te=C Bond 

Bis[2-hydroxy-5-methylphenyl] Tellurium Dichloride In a 250 ml, two-necked flask fitted with a reflux condenser and a nitrogen inlet are placed 5.0 g (18 mmol) of tellurium tetrachloride, 4g (37 mmol) of l-hydroxy-4-methylbenzenc, and 100 m/ of carbon tetrachloride. The mixture is heated to reflux under nitrogen until evolution of hydrogen chloride ceases (100 h). The mixture is then allowed to cool, the precipitate is collected and washed thoroughly with carbon tetrachloride to remove excess cresol followed by benzene to remove unrcacted tellurium tetrachloride. The residue is recrystallized from methanol yield 2.8 g (36%) m.p. 206-212°. 

Similar reactions with 1,4-dihydroxybenzene and para-substituted methoxybenzenes did not produce the expected diaryl tellurium dichlorides.  

Aromatic compounds without substituents promoting electrophilic substitution or with substituents poor in this respect can be forced to condense with tellurium tetrachloride at higher temperatures in the presence of aluminum trichloride (Table 16, p. 529). In this manner, benzene, toluene, chlorobenzene, and bromobenzene were converted to diaryl tellurium dichlorides. 

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Aromaticity (Section 114) Special stability associated with aromatic compounds... 

A combination of Cp nCX —A CXC) (where = cyclopentadienyl) effectively promotes the Friedel-Crafts coupling of glycosyl fluorides with aromatic compounds, such as trimethoxyben2ene or methoxynaphthalenes. The derived C-aryl glycosides are potent antitumor agents (39). 

Uses. The reaction of S2CI2 with aromatic compounds can yield disulfides or mixtures of mono-, di-, and polysulfides. 

Side-chain anionic alkylation reactions with aromatic compounds take place when cataly2ed with strong basic catalysts, like Na—K (228). The yield is 83% when o-xylene reacts with butadiene... 

It resembles tetracyanoethylene in that it adds reagents such as hydrogen (31), sulfurous acid (31), and tetrahydrofuran (32) to the ends of the conjugated system of carbon atoms suffers displacement of one or two cyano groups by nucleophilic reagents such as amines (33) or sodiomalononittile (34) forms TT-complexes with aromatic compounds (35) and takes an electron from iodide ion, copper, or tertiary amines to form an anion radical (35,36). The anion radical has been isolated as salts of the formula (TCNQ) where is a metal or ammonium cation, and n = 1, 1.5, or 2. Some of these salts have... 

These are subdivided into (a) compounds isomeric with aromatic compounds in which the ring contains two double bonds but also an hybridized carbon (7 systems Scheme 6) or a quaternary nitrogen atom (9 systems Scheme 7). 

Following the classification of Chapter 4.01, three classes will be considered, (a) Compounds isomeric with aromatic compounds (6), (7) and (8). The quaternary, non-aromatic salts (Scheme 7, Chapter 4.01) will be discussed only in connection with protonation studies which lead to the conclusion of their non-existence. The carbonyl derivatives (9), (10), (13) and (14) will also be included here because it is possible to write an aromatic tautomer for each one, (9 )-(14 ), even if it is energetically unfavoured, (b) Dihydro compounds. In this class not only pyrazolines (15), (16) and (17) but also pyrazolidinones (18) and pyrazolinediones like (1) are included, (c) Tetrahydro compounds. Besides the pyrazolidines (19), the pyrazolidinetriones (2) are included here. 

In 1968 the Monsanto Company announced the availability of novel soluble low molecular weight polyphenylene resins. These may be used to impregnate asbestos or carbon fibre and then cross-linked to produce heat-resistant laminates. The basic patent (BP 1037111) indicates that these resins are prepared by heating aromatic sulphonyl halides (e.g. benzene-1,3-disulphonyl dichloride) with aromatic compounds having replaceable nuclear hydrogen (e.g. bisphenoxy-benzenes, sexiphenyl and diphenyl ether). Copper halides are effective catalysts. The molecular weight is limited initially by a deficiency in one component. This is added later with further catalyst to cure the polymer. 

The mechanism of reaction with steroids has not been elucidated. Various nonquantitative reactions occur simultaneously. Cyclopentenyl cations have been postulated as intermediates which condense with anisaldehyde to yield colored compounds [4]. It is probable that triphenylmethane dyes are also formed with aromatic compounds. 

Tetracyanoethylene yields a colored it-complex with aromatic compounds in the case of aromatic amines, phenols and indoles these then react to yield the corresponding tricyanovinyl derivatives [3, 4]. 

Reaction of perfluoroalkanesulfonyl chlorides with aromatic compounds m the presence of dichloro bis(triphenylphosphine)ruthemum (II) gives perfluoro alkylated products [/i52] (equation 139)... 

The photochemical cycloadditions of alkenes and alkynes with aromatic compounds have received by far the most attention. Yields of [2+2] cydoadducts can be good, but reaction times are often long and secondary rearrangement products are common [139, 140, 141,142, 143,144, 145,146] (equations 63-65). The pioneering mechanistic and synthetic work on aromatic photocycloadditions has been reviewed [147],... 

Chirality center, 292 detection of, 292-293 Eischer projections and, 975-978 R,S configuration of, 297-300 Chitin, structure of, 1002 Chloral hydrate, structure of, 707 Chloramphenicol, structure of, 304 Chlorine, reaction with alkanes, 91-92,335-338 reaction with alkenes, 215-218 reaction with alkynes, 262-263 reaction with aromatic compounds, 550 Chloro group, directing effect of, 567-568... 

Aromatic compounds that do not contain meta-directing groups can be converted to diarylamines by treatment with aryl azides in the presence of phenol at — 60°C ArH -f- Ar N3 —> ArNHAr. Diarylamines are also obtained by the reaction of N-arylhydroxylamines with aromatic compounds (benzene, toluene, anisole) in the presence of F3CCOOH ArH -f Ar NHOH ArNHAr. ... 

The highly reactive species methylene inserts into C—H bonds,both aliphatic and aromatic,though with aromatic compounds ring expansion is also possible (see 15-62). This version of the reaction is useless for synthetic purposes because of its nonselectivity (see p. 248). This contrasts with the metal carbene insertion reaction, which can be highly selective, and is very useful in synthesis. Alkylcarbenes usually rearrange rather than give insertion (p. 249), but, when this is impossible. 

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