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Of aromatic compounds

The nitration, sulphonation and Friedel-Crafts acylation of aromatic compounds (e.g. benzene) are typical examples of electrophilic aromatic substitution. [Pg.155]

Hammen equation A correlation between the structure and reactivity in the side chain derivatives of aromatic compounds. Its derivation follows from many comparisons between rate constants for various reactions and the equilibrium constants for other reactions, or other functions of molecules which can be measured (e g. the i.r. carbonyl group stretching frequency). For example the dissociation constants of a series of para substituted (O2N —, MeO —, Cl —, etc.) benzoic acids correlate with the rate constant k for the alkaline hydrolysis of para substituted benzyl chlorides. If log Kq is plotted against log k, the data fall on a straight line. Similar results are obtained for meta substituted derivatives but not for orthosubstituted derivatives. [Pg.199]

We will show here the classification procedure with a specific dataset [28]. A reaction center, the addition of a C-H bond to a C=C double bond, was chosen that comprised a variety of different reaction types such as Michael additions, Friedel-Crafts alkylation of aromatic compounds by alkenes, or photochemical reactions. We wanted to see whether these different reaction types can be discerned by this... [Pg.193]

The catalyst is inactive for the hydrogenation of the (isolated) benzene nucleus and so may bo used for the hydrogenation of aromatic compounds containing aldehyde, keto, carbalkoxy or amide groups to the corresponding alcohols, amines, etc., e.g., ethyl benzoate to benzyl alcohol methyl p-toluate to p-methylbenzyl alcohol ethyl cinnamate to 3 phenyl 1-propanol. [Pg.873]

Determination of purity. The ultraviolet and visible absorption is often a fairly intensive property thus e values of high intensity bands may be of the order of 10 -10 . In infrared spectra e values rarely exceed 10 . It is therefore often easy to pick out a characteristic band of a substance present in small concentration in admixture with other materials. Thus small amounts of aromatic compounds can be detected in hexane or in cyclohexane. [Pg.1149]

Studies on a large number of aromatic compounds have revealed that for CTAB the largest shift occurs for the alkyl chain protons near the surfactant headgroup, whereas in SDS nearly all proton signals are shifted significantly " ". For SDS, the most pronounced shifts are observed for protons around the centre of the chain. This result has been interpreted in terms of deeper penetration of... [Pg.145]

During my Cleveland years, I also continued and extended my studies in nitration, which I started in the early 1950s in Hungary. Conventional nitration of aromatic compounds uses mixed acid (mixture of nitric acid and sulfuric acid). The water formed in the reaetion dilutes the acid, and spent aeid disposal is beeoming a serious environ-... [Pg.104]

Nitronium salts in solution in inert organie solvents have been used in reeent years to nitrate a wide range of aromatic compounds. Yields are generally good, but in preparative work the method is advantageous only in speeial cases, notably where the aromatie contains a hydrolysable substituent ( 4.4). [Pg.2]

A simple kinetic order for the nitration of aromatic compounds was first established by Martinsen for nitration in sulphuric acid (Martin-sen also first observed the occurrence of a maximum in the rate of nitration, occurrii for nitration in sulphuric acid of 89-90 % concentration). The rate of nitration of nitrobenzene was found to obey a second-order rate law, first order in the concentration of the aromatic and of nitric acid. The same law certainly holds (and in many cases was explicitly demonstrated) for the compounds listed in table 2.3. [Pg.15]

Investigations of the solubilities of aromatic compounds in concentrated and aqueous sulphuric acids showed the activity coefficients of nitrocompounds to behave unusually when the nitro-compound was dissolved in acid much more dilute than required to effect protonation. This behaviour is thought to arise from changes in the hydrogenbonding of the nitro group with the solvent. [Pg.18]

The activity coefficients in sulphuric acid of a series of aromatic compounds have been determined. The values for three nitro-com-pounds are given in fig. 2.2. The nitration of these three compounds over a wide range of acidity was also studied, and it was shown that if the rates of nitration were corrected for the decrease of the activity coefficients, the corrected rate constant, varied only slightly... [Pg.18]

Olah s original preparative nitrations were carried out with mixtures of the aromatic compound and nitronium salt alone or in ether, and later with sulpholan as the solvent. High yields of nitro-compounds were obtained from a wide range of aromatic compounds, and the anhydrous conditions have obvious advantages when functional groups such as cyano, alkoxycarbonyl, or halogenocarbonyl are present. The presence of basic fimctions raises difficulties with pyridine no C-nitration occurs, i-nitropyridinium being formed. ... [Pg.61]

Quantitative eomparisons of aromatic reactivities were made by using the competitive method with solutions of nitronium tetrafluoroborate in sulpholan, and a concentration of aromatic compounds 10 times that of the salt. To achieve this condition considerable proportions of the aromatic compoimds were added to the medium, thus depriving the sulpholan of its role as true solvent thus, in the nitration of the alkyl- and halogeno-benzenes, the description of the experimental method shows that about 50-60 cm of mixed aromatic compounds were dissolved in a total of 130 cm of sulpholan. [Pg.62]

TABLE 4.1 Nitration of aromatic compounds relative rates at 25 °C... [Pg.63]

TABLE 4.2 Nitration of aromatic compounds isomer proportions and partial rate factors ... [Pg.64]

The authors of this work were concerned chiefly with additions to alkenes, and evidence about the mechanism of aromatic nitration arises by analogy. Certain aspects of their work have been repeated to investigate whether the nitration of aromatic compounds shows the same phenomena ( 5-3-6). It was shown that solutions of acetyl nitrate in acetic anhydride were more powerful nitrating media for anisole and biphenyl than the corresponding solutions of nitric acid in which acetyl nitrate had not been formed furthermore, it appeared that the formation of acetyl nitrate was faster when 95-98% nitric acid was used than when 70 % nitric acid was used. [Pg.85]

Recent experiments have shown that the concentration of aromatic compound needed to maintain zeroth-order kinetics (see below) was much greater than for nitrations with solutions of nitric acid in some inert organic solvents reactions which were first order in the concentration of the aromatic were obtained when [ArH] < c. 2 x io mol 1 . ... [Pg.86]

Remembering that the observed second-order rate constant is merely the rate divided by the product of the stoichiometric concentrations of aromatic compound and nitric acid, the following relationship can be... [Pg.147]

Akhrem, A. A. Reshetova, I. G. Titov, Yu. A. 1972, Birch Reduction of Aromatic Compound, Plenum New York... [Pg.361]

Palladation of aromatic compounds with Pd(OAc)2 gives the arylpalladium acetate 25 as an unstable intermediate (see Chapter 3, Section 5). A similar complex 26 is formed by the transmetallation of PdX2 with arylmetal compounds of main group metals such as Hg Those intermediates which have the Pd—C cr-bonds react with nucleophiles or undergo alkene insertion to give oxidized products and Pd(0) as shown below. Hence, these reactions proceed by consuming stoichiometric amounts of Pd(II) compounds, which are reduced to the Pd(0) state. Sometimes, but not always, the reduced Pd(0) is reoxidized in situ to the Pd(II) state. In such a case, the whole oxidation process becomes a catalytic cycle with regard to the Pd(II) compounds. This catalytic reaction is different mechanistically, however, from the Pd(0)-catalyzed reactions described in the next section. These stoichiometric and catalytic reactions are treated in Chapter 3. [Pg.14]

Similarly to mercuration reactions, Pd(OAc)2 undergoes facile palladation of aromatic compounds. On the other hand, no reaction of aromatic compounds takes place with PdClj. PdCl2 reacts only in the presence of bases. The aro-... [Pg.55]

Mechanistic studies show that the arylation of alkenes proceeds via the palladation of aromatic compounds to form a rr-aryl-Pd bond (261), into which insertion of alkene takes place to form 262. The final step is i3-elimina-tion to form the arylated alkenes 259 and Pd(0). [Pg.56]

Three oxidative reactions of benzene with Pd(OAc)2 via reactive rr-aryl-Pd complexes are known. The insertion of alkenes and elimination afford arylalk-enes. The oxidative functionalization of alkenes with aromatics is treated in Section 2.8. Two other reactions, oxidative homocoupling[324,325] and the acetoxylation[326], are treated in this section. The palladation of aromatic compounds is possible only with Pd(OAc)2. No reaction takes place with PdCl2. [Pg.74]

Thallation of aromatic compounds with thallium tris(trifluoroacetate) proceeds more easily than mercuration. Transmetallation of organothallium compounds with Pd(II) is used for synthetic purposes. The reaction of alkenes with arylthallium compounds in the presence of Pd(Il) salt gives styrene derivatives (433). The reaction can be made catalytic by use of CuCl7[393,394], The aryla-tion of methyl vinyl ketone was carried out with the arylthallium compound 434[395]. The /9-alkoxythallium compound 435, obtained by oxythallation of styrene, is converted into acetophenone by the treatment with PdCh[396]. [Pg.83]

The NMR spectra of thiazoles show the same behavior as those of aromatic compounds, but the chemical shifts also depend on the two heteroatoms. [Pg.342]

All compounds that contain a benzene ring are aromatic and substituted derivatives of benzene make up the largest class of aromatic compounds Many such compounds are named by attaching the name of the substituent as a prefix to benzene... [Pg.432]

We 11 examine the chemical properties of aromatic compounds from two different perspectives... [Pg.438]

Because acylation of an aromatic ring can be accomplished without rearrangement it is frequently used as the first step m a procedure for the alkylation of aromatic compounds by acylation-reduction As we saw m Section 12 6 Friedel-Crafts alkylation of ben zene with primary alkyl halides normally yields products having rearranged alkyl groups as substituents When a compound of the type ArCH2R is desired a two step sequence IS used m which the first step is a Friedel-Crafts acylation... [Pg.486]

Friedel-Crafts acylation of aromatic compounds (Section 12 7) Acyl chlorides and carboxylic acid anhydrides acylate aromatic rings in the presence of alumi num chloride The reaction is electrophil ic aromatic substitution in which acylium ions are generated and attack the ring... [Pg.710]


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Acylation of aromatic compounds

Addition of radicals to aromatic compounds

Alkenylation of aromatic compounds

Alkylation of aromatic compounds

Alkylation of aromatic nitro compound

Alkylations of aromatic compounds

Amination, of aromatic compound

And halogenation of aromatic compounds

And nitration of aromatic compounds

And oxidation of aromatic compounds

Aromatic Amines and Other Reduction Products of Nitro Compounds

Aromatic Compounds of Antimony

Aromatic compounds biosynthesis of, from D-glucose

Aromatic compounds nomenclature of benzene derivatives

Aromatic compounds oxidation of substituents

Aromaticity of Organosulphur Compounds

Aromaticity of heterocyclic compounds

Aromatization of alicyclic compounds

Aromatization of dihydro compounds

Arylation of aromatic compounds

Basic Principles Synthons and Reagents Synthesis of Aromatic Compounds

Biodegradation of aromatic compounds

Biosynthesis of aromatic compounds from

Birch reduction of aromatic compounds

Black Sheep of the Family Heterocyclic Aromatic Compounds

Bromination of aromatic compounds

Bromination of aromatic compounds, comparison

Cathodic Reduction of Aromatic and Heterocyclic Halogen Compounds

Chemical reactions of aromatic compounds

Chemistry of Aromatic Compounds

Chlorination of aromatic compounds

Chloromethylation, of aromatic compounds

Complex Formation of Anionic Surfactants with Aromatic Compounds

Complex Formation of Aromatic Compounds Containing an Hetero Ring

Compounds of Aromatic Ring Systems

Compounds of Aromatic Ring Systems E. O. Fischer and H. P. Fritz

Compounds of Aromatic Ring Systems and Metals

Cyanation of aromatic compounds

Cycloaddition Reactions of Aromatic Compounds

Degradation of aromatic compounds

Derivatives of Aromatic Heterocyclic Compounds

Dihydroxylation of aromatic compounds

Dimetallation of Aromatic Compounds

Direct Hydroxylation of Aromatic Compounds

Effect of Heavy Atoms on Intercombinational Transitions in Aromatic Compounds

Electrolysis of Aromatic Compounds

Electron-transfer Reactions of Aromatic Compounds

Electrophilic aromatic substitution of heteroaromatic compounds

Electrophilic substitution of aromatic compounds

Examples of aromatic compounds

Excited States of Lignin Aromatic Carbonyl Model Compounds

Fluorination of aromatic compounds

Formation of Surfactants with Aromatic Compounds and their Pharmaceutical Applications

Formation of aromatic compounds

Formylation: of aromatic compounds

Fractionation of aromatic compounds

Glucose biosynthesis of aromatic compounds

Halogenation of aromatic compounds

Homocoupling and Oxidative Substitution Reactions of Aromatic Compounds

Hydrogenation of Heterocyclic Aromatic Compounds

Hydrogenation of aromatic compounds

Hydrogenation of aromatic nitro compounds

Hydroxylation of Unsaturated or Aromatic Compounds and the NIH Shift

Hydroxylation of aliphatic and aromatic compounds

Hydroxylation of aromatic compounds

Induced Circular Dichroism of Aromatic Compounds Bound to Proteins

Interactions of Cyclic Peptides with Aromatic Compounds

Iodination of aromatic compounds

Lithiation of Aromatic Compounds (2-Dimethylamino-5-methylphenyl)diphenylcarbinol

MOLECULAR ORBITALS OF AROMATIC AND ANTIAROMATIC COMPOUNDS

Mercuration, of aromatic compounds

Methods for the Preparation of Aromatic and Heteroaromatic Diazo Compounds

Nitration of Aromatic Compounds Using a Recyclable Catalyst

Nitration of aromatic and heterocyclic compounds

Nitration of aromatic compounds

Nomenclature of aromatic compounds

OXIDATIVE DIMERIZATION OF AROMATIC AMINES TO AZO COMPOUNDS

Of oxygenated aromatic compounds

Of polycyclic aromatic compounds

Oxidation and Reduction of Aromatic Compounds

Oxidation of Aromatic Compounds to Quinones

Oxidation of aromatic amines and nitroso compounds

Oxidation of aromatic compounds

Oxidative coupling of aromatic compounds

Oxidative degradation, of aromatic compounds, by Pseudomonas

Oxidative of aromatic compounds

PHOTOCHEMISTRY OF AROMATIC NITRO COMPOUNDS

PROPERTIES OF AROMATIC COMPOUNDS

Palladation of Aromatic Compounds

Partial reduction, of aromatic compounds

Phosphorescence of Aromatic Compounds

Photo-Diels-Alder Cycloaddition Reactions of Aromatic Compounds

Photo-Induced Hydrogen Abstraction and Addition Reactions of Aromatic Compounds

Photochemical Isomerisation of Aromatic Compounds

Photochemical Reactions of Aromatic Compounds

Photochemistry of Aromatic Compounds

Photocycloaddition of Aromatic Compounds

Photodimerization Reactions of Aromatic Compounds

Photodimerization and Photocycloaddition Reactions of Aromatic Compounds

Photoisomerization Reactions of Aromatic Compounds

Photorearrangement Reactions of Aromatic Compounds

Photosubstitution Reactions of Aromatic Compounds

Polycylic aromatic musk compounds in sewage treatment plant effluents of Canada and Sweden

Propargylation of Aromatic Compounds with Propargylic Alcohols

Propargylation of Heteroaromatic and Aromatic Compounds with Propargylic Alcohols

Propargylation of aromatic compounds

Properties and Uses of Aromatic Compounds

Protonation, of aromatic compounds

REACTIVITY OF NON-AROMATIC COMPOUNDS

Radical Reactions of Aromatic Compounds with Captodative Substitution

Raman frequencies of aromatic compounds

Reaction Bromination of an Aromatic Compound

Reaction C.—Oxidation of the Side Chain in Aromatic Compounds

Reaction XLIX.—(a) Action of Cuprous Potassium Cyanide on Aromatic Diazonium Compounds (Sandmeyer)

Reactions and characterisation of aromatic nitro compounds

Reactions in Side Chains of Aromatic Compounds

Reactions of Aromatic Compounds

Reactions of Aromatic Compounds Electrophilic Substitution

Reactions of NO2 with Aromatic Compounds

Reactions of Non-aromatic Compounds

Reactions of Polycyclic Aromatic Compounds

Reactivity of Polycyclic Aromatic Compounds

Reduction of aromatic compounds

Reduction of aromatic compounds to dihydroaromatics by sodium and ammonia

Reduction of aromatic nitro compound

Regioselective Synthesis of Disubstituted Aromatic Compounds

Relative Reactivities of Several Aromatic Compounds

Replacement of NH2 in aromatic compounds by Cl or Br (Schwechten reaction)

Replacement of NH2 in aromatic compounds by iodine

Replacement of NH2 in aromatic or heterocyclic compounds by fluorine (Schiemann reaction)

Replacement of hydrogen by halogen in aromatic compounds general

Replacement of hydrogen by halogen in aromatic nitro compounds

Ring current of aromatic compounds

SYNTHESIS OF SUBSTITUTED AROMATIC COMPOUNDS

Selective dealkylation of aromatic alkoxylated compounds

Silylation of aromatic compound

Sources and Names of Aromatic Compounds

Spectroscopy of aromatic compounds

Substitution reactions of aromatic compounds

Sulfonation of aromatic compounds

Sulfonylation, of aromatic compounds

Summary Reactions of Aromatic Compounds

Synthesis of Aromatic Compounds

THE VILSMEIER REACTION OF NON-AROMATIC COMPOUNDS

Thallation of aromatic compounds

Toxicity of aromatic compounds

Trifluoromethylation of aromatic compounds

Tropospheric Chemistry of Aromatic Compounds Emitted from Anthropogenic Sources

Valence-bond Isomers of Aromatic Compounds

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