Ferric chloride, as catalyst

Preparation of 1,3-Diphenyl-2,2-Dimethylpropanone-1 Sodamide was prepared from 12.5 grams of sodium added in small portions to 600 cc of liquid ammonia with 1 gram of hydrous ferric chloride as catalyst. The ammonia was replaced by 200 cc of dry toluene and without delay a solution of 74 grams of isobutyrophenone and 76.5 grams of benzyl bromide in 200 cc of benzene was slowly added with stirring. The reaction mixture was heated on a boiling water bath for 48 hours. Water was then added, the organic layer separated and the product isolated by distillation. The 1,3-diphenyl-2,2-dimethylpropanone-1 boiled from 142°-143°C at a pressure of 3 mm, t ° 1.5652. 

The polymerisation of benzene through repeated nucleophilic substitutions on the rings was studied by Kovacic et al. using ferric chloride as catalyst and water as cocatalyst. This system is of course outeide the realm of cationic polymerisation throu the double bcmd of an olefin, but illustrates well the role of water in Friedel-Crafts polycondensations. The authors showed that the rate of this reaction went throu a maximum at a catalyst/cocatalyst ratio of one and attributed this observation to the high activity of ferric chloride monohydrate ... 

Alkenylation of Grignard re emts. Facile vinylation of a Giignard reagent can be achieved with vinyl bromide with ferric chloride as catalyst and THF as solvent. For example, the reaction of S-hexenylmagnesium bromide with vinyl bromide in THF at 25° catalyzed by ferric chloride gives 1,7-octadiene in 64% yield ... 

Sodium amide is prepared by the reaction of sodium and ammonia in the presence of ferric chloride as catalyst. 

AUenes. Allenes are formed in moderate to high yield by the reaction of propargylic chlorides (terminal and nonterminal) with primary and secondary Grignard reagents (25-50% excess) in the presence of ferric chloride as catalyst. Examples ... 

Use of ferric chloride as catalyst in SmE mediated coupling reactions... 

Because of isomerization, alkylation of benzene with tertiary alkyl haUdes can also yield secondary alkylbenzenes rather than only tertiary alkylbenzenes (20). For example, the / fAhexylbenzene, which is first formed by the reaction of benzene with 2-chloro-2,3-dimethylbutane and AlCl isomerizes largely to 2,2-dimethyl-3-phenylbutane by a 1,2-CH2 shift. With ferric chloride as the catalyst, / fAhexylbenzene does not undergo isomerization and is isolated as such. 

Carbon Disulfide Chlorination. The chlorination of carbon disulfide [75-15-0] is a very old method of producing carbon tetrachloride that is still practiced commercially in the United States. In this process CS2 reacts continuously with chlorine in an annular reactor at 105—130°C. Product CCl is separated by distillation to a CS2 content of 0—5 ppm. By-product S2CI2 is reduced in a reactor at 450°C with hydrogen without a catalyst to give sulfur of 99.985% purity (32). Other processes use ferric chloride as a catalyst (33,34). 

Dichloroethane is produced by the vapor- (28) or Hquid-phase chlorination of ethylene. Most Hquid-phase processes use small amounts of ferric chloride as the catalyst. Other catalysts claimed in the patent Hterature include aluminum chloride, antimony pentachloride, and cupric chloride and an ammonium, alkaU, or alkaline-earth tetrachloroferrate (29). The chlorination is carried out at 40—50°C with 5% air or other free-radical inhibitors (30) added to prevent substitution chlorination of the product. Selectivities under these conditions are nearly stoichiometric to the desired product. The exothermic heat of reaction vapori2es the 1,2-dichloroethane product, which is purified by distillation. 

Biphenyl was once used extensively for the production of polychlorinated biphenyls (PCBs) before their production was banned in the United States in 1979. PCBs are formed by direct substitution of hydrogen atoms in biphenyl with chlorine using chlorine gas under pressure with a ferric chloride (FeCl3) catalyst. There are 209 possible PCB compounds referred to as congeners. PCBs were discovered in 1865 as a by-product of coal tar and first synthesized in 1881. Commercial production of PCBs, originally called chlorinated diphenyls, began in 1929 by the Swann Chemical Company located in Anniston, Alabama. Swann was taken over by Monsanto in 1935. 

Since nitric acid, especially red fuming nitric acid RFNA which contains a small amount of nitrogen oxides, reacts vigorously with aromatic amines, during World War II the Germans employed solutions of these amines (e.g. aniline or phenylenediamine) in benzene or xylene as the combustible component. They added a small amount of ferric chloride as a reaction catalyst to the nitric acid. It was also shown that the addition of vinyl ethers to amine solutions reduces the induction period. 

This reaction was studied by MacMullin with anhydrous ferric chloride as a catalyst at 55°C in the experiments the amount of chlorine introduced was varied with the change in reaction time. 

Polyfluorene was first synthesized by Fukuda et al. via oxidative polymerization of huorene monomers using ferric chloride as a catalyst.2,11 Both mono- and dialkyl-substituted polyfluorenes were synthesized. Figure 10.1 shows the repeat unit of poly(9,9/-dialkyl-huorene-2,7-diyl). The polymers are soluble in common solvents such as chloroform, dichloromethane, and toluene. Figure 10.2 shows the absorption and fluorescence spectra of a solution of poly(9,9/-dihexylfluorene-2,7-diyl) (PDHF) in chloroform.11 The onset of the tt-tt absorption is at 420 nm, rising to a peak at 380 nm, yielding an optical gap of 2.95 eV. The fluorescence spectrum contains vibronic peaks at 417 and 440 nm and a shoulder at 470 480 nm. 

Liquid phase Chlorination of Benzene. The chlorination of benzene is carried out in iron vessels, usually with ferric chloride as a catalyst. Anhydrous benzene takes up chlorine readily in the presence of a carrier, and the heat of the reaction must be controlled by cooling or refluxing systems to maintain optimum temperature. When only monochlorobenzene is desired, optimum yields may be obtained in a batch reactor at 30-40 C, using 0.6 mole of chlorine per mole of benzene. 

Let us imagine ourselves in the mid-nineteenth century and examine the evidence on which chemists attempted to build a model for the structure of benzene. First, because the molecular formula of benzene is CeHe, it seemed clear that the molecule must be highly unsaturated. Yet benzene does not show the chemical properties of alkenes, the only unsaturated hydrocarbons known at that time. Benzene does undergo chemical reactions, but its characteristic reaction is substitution rather than addition. When benzene is treated with bromine in the presence of ferric chloride as a catalyst, for example, only one compound with the molecular formula CeHsBr forms ... 

The first real attempt to prepare H-H PVC was made somewhat later the starting material polybutadiene had 95 - 98% cis-1,4 structure. The chlorination was carried out in trichloroacetonitrile at 0°C. with ferric chloride as the catalyst in order to avoid substitution reactions. Initial work also resulted in crosslinked polymers, but later it was found that when the reaction was carried out in dilute solution, completely soluble polymers with inherent viscosities ranging from 1 to 5 were obtained. 

Wu and collaborators devised a palladium-catalyzed one-pot synthesis of 4-imino-3,4-dihydroquinazolin-2-ylphosphonates 88, involving the treatment of 2-iodoarylcarbodiimides 89 with isocyanides, and phosphites in the presence of palladium(II) acetate as the catalyst, 1,1 -bis(diphenylphosphino) ferrocene (dppf) as the ligand, ferric chloride as the Lewis acid, which aids... 

Chemists concluded, therefore, that aU six hydrogens of benzene must be equivalent. When bromobenzene is treated with bromine in the presence of ferric chloride as a catalyst, three isomeric dibromobenzenes are formed. 

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