Chlorobenzene, derivative

A change in space group has also been observed for [Fe(3-OEt-salA-PA)2]C104-C6H5X (X=C1, Br) [128]. The space group for the chlorobenzene derivative is P2 /c at 296 K and converts to P2i/a at 158 K. A similar trans-... 

Challenged by Thorpe ("The polarity theory explains everything and predicts nothing"), 120 Robinson made two specific predictions for substitution in nitrobenzene and chlorobenzene derivatives, which he said would be verified in his laboratory by Mr. Oxford. 121... 

Derivatives of chlorobenzene are of course the most important, as they are the most readily available. For certain syntheses nitro derivatives of fluoro- or bromo-benzene are used, They may be of value sometimes, since the former are less reactive and the latter more reactive than chlorobenzene derivatives. For example, recently 2,4-dinitrofluorobenzene has been widely applied in the elucidation of the structure of peptides (Sanger [1]). 

Aryne intermediate An intermediate formed in the substitution reaction of a chlorobenzene derivative when treated with a very strong base such as sodamide. The intermediate has a triple bond in the ring. 

Further examples of phosphine-ffee Pd-catalyzed Suzuki coupling were reported by Shreeve et al. [224]. They applied the monoquaternary 2,2 -bisimidazolium-based ionic liquid shown above in Table 5.3-9 (entry 1) as ionic liquid and ligand and reported good results for the transformation of phenylboronic acid with chlorobenzene derivatives. The system remained active for 14 consecutive rans with yields of 80-90%, depending on the electron-donating or -withdrawing properties of the substituents at the chlorobenzene substrate. 

In these cases, the chlorobenzenes act as electron acceptors while the benzidine molecule behaves as an electron donor. The effect of chlorine substitution on the aromaticity of the planar benzene ring of the chlorobenzene derivatives is assessed from the nucleus independent chemical shift (NICS) criterion proposed by Schleyer et al. [338]. Among the various global and local molecular descriptors, electrophilicity (m) is found to be the most appropriate reactivity parameter regarding toxicity... 

Other significant processes for the conversion of benzene include hydrogenation to produce cyclohexane, oxidation to manufacture maleic anhydride, nitration to obtain nitrobenzene as an intermediate in the production of aniline, and halogenation to obtain chlorobenzene derivatives. 

COCl, and — PO2CI2 binding groups of p-chlorobenzene derivatives. The large decrease in CPD down to —770 mV, thatis. 

Fig. 11 The change in contact potential difference of modified ITO as a function of (a) benzoyl chlorides with various terminal groups and (b) —SO2CI, —COCl, and —PO2CI2 binding groups of p-chlorobenzene derivatives [312].

Tab. 7 Work function of SAM modified ITO with —SO2CI, —COCI, and —PO2CI2 binding groups ofp-chlorobenzene derivatives estimated from Vcpd and the work function of 4.5 0.1 eV for cleaned ITO [312]...

Methyl iodide ethyl bromide ethyl iodide, higher alkyl halides, chloroform, iodoform, carbon tetrachloride, chlorobenzene, bromobenzene, iodobenzene, benzyl chloride (and nuclear substituted derivatives)... 

The name D.D.T. is derived from dichlorodiphenylfrichloroethane this is a misnomer since the name represents 27 different compounds. As commonly employed it refers to 2 2-6ts(p-chlorophenyl)-l 1 1-trichloroethane. It is conveniently prepared by the condensation of chlorobenzene and chloral hydrate in the presence of concentrated sulphuric acid ... 

The relative rate is derived from the kinetic data " by stepwise comparison with m-nicrotoluene, chlorobenzene and benzene. Kinetic data are available for the acidity range 8o-o-Q5-6 % sulphuric acid. See also ref. 43. 

Chlorides are inert. However, the reaction ofp-chlorobenzophenone (9) with a styrene derivative proceeds satisfactorily at 150 C by u.sing dippb [l,4-bis(-diisopropylphosphino)butane] as a ligand to give the stilbene derivative 10. However, dippp [l,3-bis(diisopropylphosphino)propane] is an ineffective ligand[13]. On the other hand, the coupling of chlorobenzene with styrene proceeds in the presence of Zn under base-free conditions to afford the cis-stilbene 11 as a main product with evolution of H . As the ligand, dippp is... 

The benzoic acid derivative 457 is formed by the carbonylation of iodoben-zene in aqueous DMF (1 1) without using a phosphine ligand at room temperature and 1 atm[311]. As optimum conditions for the technical synthesis of the anthranilic acid derivative 458, it has been found that A-acetyl protection, which has a chelating effect, is important[312]. Phase-transfer catalysis is combined with the Pd-catalyzed carbonylation of halides[3l3]. Carbonylation of 1,1-dibromoalkenes in the presence of a phase-transfer catalyst gives the gem-inal dicarboxylic acid 459. Use of a polar solvent is important[314]. Interestingly, addition of trimethylsilyl chloride (2 equiv.) increased yield of the lactone 460 remarkabiy[3l5]. Formate esters as a CO source and NaOR are used for the carbonylation of aryl iodides under a nitrogen atmosphere without using CO[316]. Chlorobenzene coordinated by Cr(CO)j is carbonylated with ethyl formate[3l7]. 

Halides derived from certain heterocyclic aromatic compounds are often quite reac tive toward nucleophiles 2 Chloropyridme for example reacts with sodium methoxide some 230 million times faster than chlorobenzene at 50°C... 

Above 100°C, most polyolefins dissolve in various aHphatic and aromatic hydrocarbons and their halogenated derivatives. For example, polybutene dissolves in benzene, toluene, decalin, tetralin, chloroform, and chlorobenzenes. As with other polyolefins, solubiHty of PB depends on temperature, molecular weight, and crystallinity. 

A Methylamino)phenol. This derivative, also named 4-hydroxy-/V-methy1ani1ine (19), forms needles from benzene which are slightly soluble in ethanol andinsoluble in diethyl ether. Industrial synthesis involves decarboxylation of A/-(4-hydroxyphenyl)glycine [122-87-2] at elevated temperature in such solvents as chlorobenzene—cyclohexanone (184,185). It also can be prepared by the methylation of 4-aminophenol, or from methylamiae [74-89-5] by heating with 4-chlorophenol [106-48-9] and copper sulfate at 135°C in aqueous solution, or with hydroquinone [123-31 -9] 2l. 200—250°C in alcohoHc solution (186). 

Nucleophilic Substitutions of Benzene Derivatives. Benzene itself does not normally react with nucleophiles such as haUde ions, cyanide, hydroxide, or alkoxides (7). However, aromatic rings containing one or more electron-withdrawing groups, usually halogen, react with nucleophiles to give substitution products. An example of this type of reaction is the industrial conversion of chlorobenzene to phenol with sodium hydroxide at 400°C (8). 

Ortho- and/ i ra-phenylphenols are commercially significant biphenyl derivatives that do not involve biphenyl as a starting material. Both are produced as by-products from the hydrolysis of chlorobenzene [108-90-7] with aqueous sodium hydroxide (68). o-Phenylphenol, ie, l,l-biphenyl-2-ol [90-43-7], particularly as its sodium salt, is widely used as a germicide or fungicide. Pi ra-phenylphenol [92-69-3] with formaldehyde forms a resin used in surface coatings. 

Organic chemicals made directly from chlorine include derivatives of methane methyl chloride, methylene chloride, chloroform, carbon tetrachloride, chlorobenzene ortho- and para-dichlorobenzenes ethyl chloride, and ethylene chloride. 

Tnfluoroacetic anhydnde in a mixture with sulfuric acid is an efficient reagent for the sulfonylation of aromatic compounds [44] The reaction of benzene with this system in nitromethane at room temperature gives diphenyl sulfone in 61% yield Alkyl and alkoxy benzenes under similar conditions form the corresponding diaryl sulfones in almost quantitative yield, whereas yields of sulfones from deactivated arenes such as chlorobenzene are substantially lower [44] The same reagent (tnfluoroacetic anhydride-sulfunc acid) reacts with adamantane and its derivatives with formation of isomeric adamantanols, adamantanones, and cyclic sultones [45]... 

Predict the products formed when each of the following isotopically substituted derivatives of chlorobenzene is treated with sodium amide in liquid ammonia. Estimate as quantitatively as possible the composition of the product mixture. The asterisk ( ) in part (a) designates C, and D in part (b) is H. 

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). 

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