Benzene, alkylation chlorination

The spectra separate Into two large well separated groups. In the first, smaller clusters can be recognized ortho dlols, para-alkyl phenols, meta-alkyl phenols, ortho-chloro phenols, and multiply chlorinated benzenes. In the second group, these subclusters can be found ortho-alkyl phenols, benzenes bearing chlorine on alkyl side chains, and ortho-chlorotoluenes. 

The substances detected included herbicides, such as Alachlor, butachlor, atrazine, cyanazine, propazine, and simazine insecticides, such as chlordane, heptachlor, dield-rin, eldrin, and DDE as a DDT metabolite and industrial organics, which included alkylbenzenes such as toluene, xylenes, ethylbenzene alkanes such as decane through pentadecane naphtalene and methylnaphtalenes alkyl phthalates, used as plasticizers chlorinated methanes and ethanes, especially CHCI3 chlorinated benzenes and chlorinates phenols benzaldehyde dicyclopentadiene, etc. Of these compounds, the hydrocarbons are typical of oil refinery operations, and the chlorinated benzenes and phenols are associated with herbicide and insecticide production. 

The alkylation with chlorinated paraffin is used as before for the production of LAB, higher benzene alkylates and other alkylaromatics. To avoid the formation of many by-products a high excess of aromatics to chloroparaffin (ca. 10 1) is generally chosen. Unreacted benzene, di-and trialkylates are returned into the process. The ratio between AICI3 used as an alkylation catalyst and chloroparaffin is critical too. The reaction takes place at 35-90 °C and pressures of ca. 3 bar where the residence time is 5 to 60 minutes [56]. 

Like benzenes, alkyl benzenes when treated with chlorine or bromine at low temperature, in the absence of light, and in the presence of a halogen carrier undergo nuclear halogenation. 

AlClj Alkylation Process. The first step in the AIQ. process is the chlorination of / -paraffins to form primary monochloroparaffin. Then in the second step, the monochloroparaffin is alkylated with benzene in the presence of AIQ. catalyst (75,76). Considerable amounts of indane (2,3-dihydro-lH-indene [496-11-7]) and tetralin (1,2,3,4-tetrahydronaphthalene [119-64-2]) derivatives are formed as by-products because of the dichlorination of paraffins in the first step (77). Only a few industrial plants built during the early 1960s use this technology to produce LAB from linear paraffins. The C q—CC olefins also can be alkylated with benzene using this catalyst system. 

The reduction of the C— Br and C—1 group moments from 1.10 and 0.90 in bromo- and iodo-benzene to about 0.80 and 0.50 in 2-bromo- and 2-iodo-thiophene has been ascribed to the larger weight of resonance forms such as (8) and (9) in the thiophene series. The chlorine, nuclear, quadrupole, resonance frequencies of chloro-substituted thiophenes are much higher than those of the corresponding benzene derivatives. This has been ascribed to a relayed inductive effect originating in the polarity of the C—S o-bond in thiophenes. The refractive indices, densities, and surface tension of thiophene, alkyl- and halo-thiophenes, and of some other derivatives have been... 

The reactivity of Ce, C7, Cg aromatics is mainly associated with the benzene ring. Aromatic compounds in general are liable for electrophilic substitution. Most of the chemicals produced directly from benzene are obtained from its reactions with electrophilic reagents. Benzene could be alkylated, nitrated, or chlorinated to important chemicals that are precursors for many commercial products. 

Similar to the alkylation and the chlorination of benzene, the nitration reaction is an electrophilic substitution of a benzene hydrogen (a proton) with a nitronium ion (NO ). The liquid-phase reaction occurs in presence of both concentrated nitric and sulfuric acids at approximately 50°C. Concentrated sulfuric acid has two functions it reacts with nitric acid to form the nitronium ion, and it absorbs the water formed during the reaction, which shifts the equilibrium to the formation of nitrobenzene ... 

Dichloronitrotoluenes are indicated by the presence of an odd molecular ion with chlorine isotopes showing two chlorine atoms and losses of 30 and 46 Daltons. Again, when the chlorine atoms are on the benzene ring, the loss of chlorine from the molecular ion does not occur. An M - Cl ion indicates that at least one of the chlorines is on the alkyl group. 

Second-order rate coefficients have been obtained for chlorination of alkyl-benzenes in acetic acid solutions (containing up to 27.6 M of water) at temperatures between 0 and 35 °C, and enthalpies and entropies of activation (determined over 25 °C range) are given in Table 63 for the substitution at the position indicated266. 

The necessary C10/13 cut for the hydrophobic part of the molecule can be obtained by various methods. Suitable paraffins were obtained in the USA from kerosene (distillation range 200-250°C). The kerosene was extracted above all from Pennsylvania oil. These mainly straight chain paraffins with 12-14 C atoms were chlorinated and their reaction products alkylated with benzene in the presence of a Lewis acid and sulfonated with oleum. The first products in the USA were called Nacconol NR and NRSF (National Aniline and Chemical Co., NACCO ), as well as Santomerse 1 (Monsanto) [4]. 

In the second process the /z-paraffins are partially chlorinated with chlorine gas in a multistage reactor. The resulting product, a mixture of /z-paraffins and chloroparaffins, is fed, together with excess benzene, into a reactor where AlCl3-catalyzed alkylation is performed. The catalyst suspended or dissolved in the crude alkylate is then separated, while the benzene and unconverted ti-paraffins are recovered by distillation and recycled to the previous reaction stages. In the last step of the process, the LAB is separated from the heavy alkylates. This second process needs to be integrated with a chlorine production unit and with an additional industrial transformation plant which makes use of the corrosive HC1 byproduct. 

The substituent effect of vinylsilanes is similar to that of allylsilanes. The reactivity of vinylsilanes increased as the number of chlorine atoms on the silicon increased, but decreased as the number of methyl groups increased. However, vinyltrimethylsilane does not react with benzene to give alkylated products. " In the aluminum chloride-catalyzed alkylation of arenes with allylsilanes or vinylsilanes, one or more chlorine substituents on the silicon atom of silanes are required. 

Vinyldialkylsilanes and vinyltrimethylsilane having no chlorine atoms do not undergo alkylation with benzene derivatives in the presenee of aluminum chloride but vinylchlorosilanes react with benzene to give the alkylation products. The reaetivities of vinylchlorosilanes decrease in the following order vinyl(methyl)di-chlorosilane > vinyltrichlorosilane > vinyl(dimethyl)chlorosilane. 

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