Chlorobenzene, benzoylation

Halogen compounds. re-Butyl bromide Chlorobenzene AUyl bromide Benzoyl chloride. 

Halogen compounds. n-Butyl bromide Chlorobenzene Allyl bromide Benzoyl chloride. 

The reaction of diaminomethylenemalonate (1306) and benzoyl chloride in the presence of triethylamine in boiling chlorobenzene for 6 hr afforded 2-azetin-4-ones (1307) in 48-73% yields (77ZOR954). 

The rate expression Eq. 3-32 requires a first-order dependence of the polymerization rate on the monomer concentration and is observed for many polymerizations [Kamachi et al., 1978], Figure 3-2 shows the first-order relationship for the polymerization of methyl methacrylate [Sugimura and Minoura, 1966], However, there are many polymerizations where Rp shows a higher than first-order dependence on [M], Thus the rate of polymerization depends on the -power of the monomer concentration in the polymerization of styrene in chlorobenzene solution at 120°C initiated by t-butyl peresters [Misra and Mathiu, 1967]. The benzoyl peroxide initiated polymerization of styrene in toluene at 80°C shows an increasing order of dependence of Rp on [M] as [M] decreases [Horikx and Hermans, 1953], The dependence is 1.18-order at [M] = 1.8 and increases to 1.36-order at [M] = 0.4. These effects may be caused by a dependence of the initiation rate on the monomer concentration. Equation 3-28 was derived on the assumption that Rt is independent of [M], The initiation rate can be monomer-dependent in several ways. The initiator efficiency / may vary directly with the monomer concentration... 

To a solution of 40 g (1.0 moles) of sodium hydroxide in 500 ml of methanol was added 242 g (l.Omoles) of 2.6-dichloro-4-bromophenol. The pH was adjusted between 9.0 and 10.0 (preferably 9.5) by means of one or another of the reactants. The pH was determined by diluting a 2.5 g aliquot with 100 ml of 50% aqueous methanol. The alcohol and water were removed by distillation, fn a one liter round bottom flask there was introduced 100 g of the sodium salt of 2.6-dichloro-4-bromophenol, 350 ml of chlorobenzene and 40 ml of N,N-dimethylformamide. The mixture was agitated until the salt was in solution then immediately there was added 26 ml of dimethylsulfoxide. A suspension forms. The air was removed by alternate evacuation and introduction of nitrogen then there was added 1.0 g of benzoyl peroxide dissolved in 10 ml of toluene. The mixture was stirred for 80 min at 29—33° C then for 5 hours at 54—59° C. The formation of polymer was indicated by the disappearance of the particles of the suspension and an increase in the viscosity of the solution. The polymer was isolated by precipitation into acetone. After filtration the polymer was washed thoroughly with water, then with acetone and then dried at 100° C. There was obtained 60 g (theoretical) of poly-(2.6-dichloro-1.4-phenylene ether). 

Alkaline hydrolysis rates of a series of thiophenyl 4-X-benzoates (47 X = H, Me, N02) was significantly enhanced in the presence of cyclodextrins (CDs), and this was attributed to strong binding of the benzoyl moiety within the CD cavity and covalent catalysis by secondary hydroxy groups of the CDs (48).63 The effect of MeCN and MeOH on the alkaline hydrolysis of acetylsalicylic acid in aqueous micellar solutions was reported.64 Butylaminolysis of p-nitrophenyl acetate in chlorobenzene in the presence of different kinds of phase-transfer catalysts (crown ethers and gly-mes) supported the existence of a novel reaction pathway exhibiting a first-order dependence on the concentration of the phase-transfer catalyst and a second-order... 

An attempt has been made to analyse whether the electrophilicity index is a reliable descriptor of the kinetic behaviour. Relative experimental rates of Friedel-Crafts benzylation, acetylation, and benzoylation reactions were found to correlate well with the corresponding calculated electrophilicity values. In the case of chlorination of various substituted ethylenes and nitration of toluene and chlorobenzene, the correlation was generally poor but somewhat better in the case of the experimental and the calculated activation energies for selected Markovnikov and anti-Markovnikov addition reactions. Reaction electrophilicity, local electrophilicity, and activation hardness were used together to provide a transparent picture of reaction rates and also the orientation of aromatic electrophilic substitution reactions. Ambiguity in the definition of the electrophilicity was highlighted.15... 

That the chalcone units combined in a head-to-tail manner was conclusively decided by showing that the thiolane could be dehydrogenated by dichlorodicyanoquinone in boiling chlorobenzene to a dibenzoyldiphenylthiophene, 8, whose 13C NMR revealed the presence of two different benzoyl groups (18). It followed that each of the two possible modes of head-to-nead fusion of chalcone units in a thiolane could be rejected. 

Under a nitrogen blanket, a mixture of 3 g of 4-(2-piperidinoethoxy)benzoic acid hydrochloride, 2 drops of dimethylformamide, 2.5 ml of thionyl chloride and 40 ml of chlorobenzene was heated at 70°-75°C for about one hour. The excess thionyl chloride and 15-20 ml of solvent were then distilled off. The remaining suspension was cooled to ambient temperature, and to it were added 100 ml of dichloromethane, 2.7 g of 6-methoxy-2-(4-methoxyphenyl) benzo[b]thiophene and 10 g of aluminum chloride. The solution was stirred for about one hour, 7.5 ml of ethanethiol was added, and the mixture was stirred for 45 minutes more. Then 40 ml of tetrahydrofuran was added, followed by 15 ml of 20% hydrochloric acid, with an exotherm to reflux. Fifty ml of water and 25 ml of saturated aqueous sodium chloride was added. The mixture was stirred and allowed to cool to ambient temperature. The precipitate was collected by filtration and washed successively with 30 ml of water, 40 ml of 25% aqueous tetrahydrofuran, and 35 ml of water. The solids were then dried at 40°C under vacuum to obtain 5.05 g of product, which was identified by NMR as 6-hydroxy-2-(4-hydroxyphenyl)-3-[4-(2-piperidinoethoxy)benzoyl] benzo[b]thiophene hydrochloride melting point 217°C. 

Venkatesan, C., Jaimol, T., Moreau, P., Finiels, A., Ramaswamy, A. V. and Singh, A. P. Liquid phase selective benzoylation of chlorobenzene to 4,4 -dichlorobenzophenone over zeolite H-beta, Catal. Lett., 2001, 75, 119-123. 

Nitration of monosubstituted aromatics, toluene in particular, has been extensively studied using zeolites in order to direct the reaction towards the formation of the desired para-isomer. Toluene has been nitrated para-selectively with benzoyl nitrate over zeolite catalysts.[14,15] For example, when mordenite is used as a catalyst, MNTs are formed in almost quantitative yields, giving 67 % of the para-isomer in 10 min, but tetrachloromethane is required as solvent. However, the main problems associated with the use of benzoyl nitrate are handling difficulties due to its sensitivity toward decomposition, and the tendency toward detonation upon contact with rough surfaces. Nagy et a/.[19 21] reported the nitration of benzene, chlorobenzene, toluene and o-xylene with benzoyl nitrate in the presence of an amorphous aluminosilicate, as well as with zeolites HY and ZSM-11, in hexane as a... 

An analogous reagent with an azido instead of a cyano group was generated in situ and used for the azidation of polycyclic hydrocarbons such as adamantane and norbomane catalysis by benzoyl peroxide was necessary, in refluxing chlorobenzene [17]. 

The most characteristic catalytic activity of the rhodium complex was observed with the reaction of aroyl halides. The decarbonylation of aroyl halides was not satisfactory with palladium catalyst whereas they decarbonylated smoothly on heating to 200°C. with the rhodium complex. For example, when benzoyl chloride was heated with the complex at 200°C., chlorobenzene distilled oflF rapidly ith the evolution of carbon monoxide. Benzoyl bromide reacts similarly to give bromo-benzene. Phenylacetyl chloride was coi verted into benzyl chloride. Additional results are in Table II. 

Polymer X Elvanol 7130-M (100% hydrolyzed PVA) was dried in a vacuum oven at 37°C and at 8 mm Hg for 24 hours. The dried PVA was placed in molecular sieve-dried-pyridine (5% wt/vol) and heated at 70°C for 6 hours. A mixture of 0.35 mole equivalents of p-methoxycinnamoyl chloride, and 0.55 mole equivalents of benzoyl chloride was added to the swollen PVA gel in two portions. First, half the mixture was added and the reaction was stirred at 70°C for 12 hours followed by addition of the other half. After the addition of the acid chloride was complete the reaction was stirred an additional 12 hours. The reaction solution was cooled and the precipitated pyridine hydrochloride was collected by filtration. The clear pyridine solution was slowly poured into distilled water under vigorous agitation and the precipitated polymer was collected and dried. Polymer X displayed a Tg = 92°C and an I.V. = 1.15 (phenol/chlorobenzene). 

This system has been cited frequently (e.g. [96]) as a method for the production of aromatic acids. Hence, benzoic acid is formed from the hydroiysis of benzoyl chloride, prepared from benzene and an excess of liquid phosgene in the presence of dissolved aluminium(III) chloride [1754]. Toluene or chlorobenzene react similarly to give 4-chloro- or 4-methyIbenzoic acids via the corresponding acid chlorides. 

The benzoylation of both activated and deactivated aromatic compounds with benzoic acids (BACs) is achieved by using bismuth triflate (10% mol) in the presence of TFAA or heptafluorobutyric anhydride (HFBA).27 meffl-Xylene undergoes acetylation with 100% yield by using acetic acid (AAC) in the presence of TFAA under bismuth or scandium triflate catalysis (10% mol). The bismuth-triflate-catalyzed reaction can be extended to different aromatics as well as to aliphatic and aromatic carboxylic acids, giving ketones in nearly quantitative yield. Benzene and chlorobenzene are benzoylated with a BAC/HFBA mixture in the presence of bismuth triflate (10% mol), giving the corresponding BPs in 90%... 

Acylation of anisole with A AN is carried out in a mixture of GALDEN SV 135, a suitable fluorous solvent, and chlorobenzene in the presence of hafnium tetra[bis(perfluorooctanesulfonyl)amide] (1% mol) at 70°C-120°C for 1 to 5 h, giving para-methoxyacetophenone in 80% yield and 100% selectivity. It is significant to underline that aluminum chloride gives the mentioned product in only 2% yield under the present mild reaction conditions. The catalyst can be very easily recycled by directly reusing the lower fluorous catalytic phase in the successive reaction with another mixture of reactants, affording the product more than three times without decrease in catalytic activity. The catalytic process can be applied to dimethoxybenzenes and mesitylene with both aliphatic and aromatic acyl chlorides and anhydrides (80%-97% yield). Benzoylation of toluene gives para-methylbenzophenone in 35% yield. 

Benzoylation of anisole with BC at the para-position is performed in the presence of a catalytic amount of iron(III) oxide (85% yield) lower yields of 4-halobenzophenones are achieved with the weakly deactivated chlorobenzene (33%), bromobenzene (31%), and iodobenzene (30%). However, taking into account the possible leaching of active iron trichloride produced by the reaction of iron(III) oxide with hydrogen chloride, the contribution of the homogeneous iron-based Lewis acid form is strongly suspected. 

Recently Bartlett and Shimizu"3 demonstrated that triplet acetone derived from dioxetane lb chemisensitized the decomposition of benzoyl peroxide in carbon tetrachloride, affording chlorobenzene, which exhibited a photo-CINDP effect. Finally, we observed that the / -peroxylactone (60) afforded exclusively tetramethylethylene oxide when chemisensitized by lb, as shown in Eq. (46).116... 

The kinetic study of the acylation reaction of thiophene with acyl chlorides over dealuminated HY zeolites, in chlorobenzene as solvent, has been shown to follow a Langmuir-Hinshelwood type kinetic law. In liquid phase conditions, thiophene is slightly more adsorbed than the acyl chloride. Moreover, the study of the reaction with various substituted benzoyl chlorides X-CgH4-COCl shows that the nature of the substituent has very little influence on the initial rate. 

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