1- -2-propene Friedel-Crafts reaction with

Urea-formaldehyde resins can be cured with isopropylbenzene production wastes containing 200 to 300 g/liter of AICI3 as an acid hardener [189]. Isopropylbenzene is formed as an intermediate in the Hock process by a Friedel-Crafts reaction from propene and benzene. The mixture hardens in 45 to 90 minutes and develops an adhesion to rock and metal of 0.19 to 0.28 MPa for 0.2% AICI3 and 0.01 to 0.07 MPa for 0.4% AICI3, respectively. A particular advantage is the increased pot life of the formulation. 

Despite the early use of phosphonium salt melts as reaction media [12, 18, 25], the use of standard ionic liquids of type 1 and 2 as solvents for homogeneous transition metal catalysts was described for the first time in the case of chloroaluminate melts for the Ni-catalyzed dimerization of propene [5] and for the titanium-catalyzed polymerization of ethylene [6]. These inherently Lewis-acidic systems were also used for Friedel-Crafts chemistry with no added catalyst in homogeneous [7] as well as heterogeneous fashion [8], but ionic liquids which exhibit an enhanced stability toward hydrolysis, i. e., most non-chloroaluminate systems, have been shown to be of advantage in handling and for many homogeneously catalyzed reactions [la]. The Friedel-Crafts alkylation is possible in the latter media if Sc(OTf)3 is added as the catalyst [9]. 

Si-H is believed to be equivalent to H-H and hence Si-H can add a C-C multiple bond to produce SiC-CH. The reaction is usually mediated by precious metal complexes such as chloroplatinic acid in a homogeneous liquid phase. This reaction may correspond to the alkylation of Si compounds with olefins and unsaturated compounds. A typical alkylation reaction is an acid catalyzed Friedel-Crafts reaction, e.g. an alkylation of benzene with propene to yield... 

Friedel-Crafts alkylation of benzo[6]thiophene has received little attention. The published results, which deserve reexamination, indicate that exclusive 3-substitution occurs in some cases, whereas in others, 2-substitution predominates. Benzo[6]thiophene is alkylated with isopropyl chloride, isopropanol, or propene in the presence of various acid catalysts under a variety of reaction conditions to give a mixture of 2- and 3-isopropylbenzo[6]thiophene in which the 2-isomer predominates (78-92%).358 410 In contrast, alkylation with isobutene in the presence of either 80% sulfuric acid415 or 100% phosphoric acid416 is said to afford exclusively 3-/er<-butylbenzo[6]thiophene in yields of 100 and 75%, respectively. In neither case was the structure of the product rigorously confirmed. Likewise, 3-Jeri-amylbenzo [63-thiophene is the exclusive product of alkylation with tert-amyl alcohol in the presence of stannic chloride414 alkylation with pent-l-ene, hex-l-ene, and a Ci8 propylene polymer is also claimed to give... 

Friedel Crafts alkylation has been studied by Poliakoff in a continuous-flow reactor (Hitzler et al., 1998a). The reaction of mesitylene and anisole with propene or 2-propanol over a solid acid catalyst (based on a Deloxan support) in sc C02 provided exclusive formation of the monoalkylated products at 50% conversion. Use of the continuous-flow reactor prevents catalyst deactivation, and permits use of comparatively small reactors. The... 

The process is based upon three different reactions (i) Friedel-Crafts alkylation of benzene with propene to afford cumene (isopropylbenzene) (ii) cumene oxidation with oxygen to give cumyl hydroperoxide and (iii) cleavage of cumyl hydroperoxide in acidic medium to afford phenol and acetone (Equation 13.2) ... 

In the cumene process, cumene is produced from benzene and propene by Friedel-Crafts alkylation. In modern cumene plants, zeolite catalysts are used with high yields of more than 99.7% at temperatures and pressures of approximately 150 °C and 30 bar, respectively. The reaction heat is 98 kj/mol. 

Conventional Method of Producing Cumene (Fig. 75). In the past, the Friedel -Crafts alkylation of benzene was carried out together with the conversion of the polyalkylated isopropylbenzenes in a single reactor (a). The catalyst was produced directly in the reaction mixture from aluminum chippings and HCl. It formed a second separate organic phase in the reactor. The water present in the propene was simply removed mechanically, whereas the benzene used was dried over. sodium hydroxide. 

In the cumene process, benzene is first converted, via the action of propene, to isopropylbenzene (cumene) in a Friedel-Crafts type reaction. Catalysts such as AICI3, sulfuric acid, or phosphoric acid are necessary. Treating cumene with oxygen results in the formation of a hydroperoxide at the tertiary C atom, and this can be decomposed to phenol and acetone. 

The mechanism of each of the reactions in the synthesis of phenol from benzene and propene via cumene hydroperoxide requires some comment. The first reaction is a familiar one. The isopropyl cation generated by the reaction of propene with the acid (H3PO4) alkylates benzene in a typical Friedel-Crafts electrophilic aromatic substitution ... 

Friedel-Crafts type alkylations occur in systems other than alkyl halides. When 2-methyl-l-propene is treated with a catalytic amount of sulfuric acid in the presence of benzene, for example, an alkylbenzene is formed. Draw that product and draw a mechanism for its formation. Similarly, when tert-butanol is treated with a catalytic amount of sulfuric acid in the presence of toluene, a Friedel-Crafts type reaction occurs. Draw the product or products of this reaction and give a mechanism for its or their formation. 

Phenol production is typically carried out by add induced conversion of cumene hydroperoxide to phenol and acetone (Hock process). Cumene hydroperoxide is obtained by oxidation of cumene. The cumene feedstock for the latter reaction is provided by Friedel-Crafts alkylation of benzene with propene. Alternative routes (chlorobenzene hydrolysis, cydohexanol dehydrogenation, oxidative decarboxylation of benzoic acid) exist but are of much lower industrial relevance. 

Hitzler et al. (316) report the Friedel-Crafts alkylation of mesitylene (C6H3Me3) and anisole with propene or 2-propanol using a heterogeneous polysiloxane-supported solid acid catalyst (Degussa s Deloxan) in a small fixed-bed continuous reactor (10-ml volume) using SCF propene or CO2 as the reaction solvent. For the alkylation of mesitylene with propene at 160-180°C and 200 bar, yield of the monoalkylated product (l-isopropyl-2,4,6-trimethylbenzene) was only approximately 25% due to the formation of the dialkylated product as well as dimers and trimers of propene. Selectivity to the monoalkylated product was significantly higher (40% yield) for alkylation with 2-propanol in scCOa. 

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