Catalyst carbon tetrachloride

Under the influence of a ruthenium catalyst, carbon tetrachloride adds across the olefinic bond of unsaturated esters to give -trichloromethyl derivatives which, on hydrolysis, afford /8-chloro-a, w-diacids. ... 

C. Manufactured by the action of HF on CCI4 using SbClj as a catalyst. Known commercially as Freon-12 or Arcton-12. Widely used as a refrigerant and aerosol propellant. It is much less toxic than carbon tetrachloride. 

Acid Chloride Formation. Monoacid chlorides of maleic and fumaric acid are not known. Treatment of maleic anhydride or maleic acid with various reagents such as phosgene [75-44-5] (qv), phthaloyl chloride [88-95-9] phosphoms pentachloride [10026-13-8] or thionyl chloride [7719-09-7] gives 5,5-dichloro-2(5JT)furanone [133565-92-1] (4) (26). Similar conditions convert fumaric acid to fumaryl chloride [627-63-4] (5) (26,27). NoncycHc maleyl chloride [22542-53-6] (6) forms in 11% yield at 220°C in the reaction of one mole of maleic anhydride with six moles of carbon tetrachloride [56-23-5] over an activated carbon [7440-44-4] catalyst (28). 

Preparation. Thiophosgene forms from the reaction of carbon tetrachloride with hydrogen sulfide, sulfur, or various sulfides at elevated temperatures. Of more preparative value is the reduction of trichi oromethanesulfenyl chloride [594-42-3] by various reducing agents, eg, tin and hydrochloric acid, staimous chloride, iron and acetic acid, phosphoms, copper, sulfur dioxide with iodine catalyst, or hydrogen sulfide over charcoal or sihca gel catalyst (42,43). 

Manufacture. Trichloromethanesulfenyl chloride is made commercially by chlorination of carbon disulfide with the careful exclusion of iron or other metals, which cataly2e the chlorinolysis of the C—S bond to produce carbon tetrachloride. Various catalysts, notably iodine and activated carbon, are effective. The product is purified by fractional distillation to a minimum purity of 95%. Continuous processes have been described wherein carbon disulfide chlorination takes place on a granular charcoal column (59,60). A series of patents describes means for yield improvement by chlorination in the presence of dihinctional carbonyl compounds, phosphonates, phosphonites, phosphites, phosphates, or lead acetate (61). 

The sulfur monochloride formed in this reaction can be treated with additional carbon disulfide in the presence of a catalyst to yield carbon tetrachloride and sulfur. Alternatively, the sulfur monochloride and carbon tetrachloride can be... 

Carbon disulfide and chlorine react in the presence of iron catalysts to give carbon tetrachloride [56-23-5] and sulfur monochloride [10025-67-9] ... 

A typical reactor operates at 600—900°C with no catalyst and a residence time of 10—12 s. It produces a 92—93% yield of carbon tetrachloride and tetrachloroethylene, based on the chlorine input. The principal steps in the process include (/) chlorination of the hydrocarbon (2) quenching of reactor effluents 3) separation of hydrogen chloride and chlorine (4) recycling of chlorine to the reactor and (i) distillation to separate reaction products from the hydrogen chloride by-product. Advantages of this process include the use of cheap raw materials, flexibiUty of the ratios of carbon tetrachloride and tetrachloroethylene produced, and utilization of waste chlorinated residues that are used as a feedstock to the reactor. The hydrogen chloride by-product can be recycled to an oxychlorination unit (30) or sold as anhydrous or aqueous hydrogen chloride. 

Methylene chloride can also be made by reducing either chloroform or carbon tetrachloride with hydrogen over a platinum catalyst (20) or with metal hydrides (21). Chloroform is slowly reduced to methylene chloride upon warming with trisHane, Si Hg, in the absence of air as shown in equation 3. 

Hydrogenation of Carbon Tetrachloride. Carbon tetrachloride can be hydrogenated, ie, hydrodechlorinated, to chloroform over a catalyst (25,26) or thermally (27). Although there are no industrial examples of this process at this time, it will receive more attention as more carbon tetrachloride becomes available as the CFC-11 and -12 markets decline (see, Chlorocarbons and chlorohydrocarbons, carbon tetrachloride). Chloroform can be further hydrodechlorinated to methylene chloride (28,29). 

Carbon tetrachloride can be reduced to chloroform using a platinum catalyst (10) or zinc and acid. With potassium amalgam and water, carbon tetrachloride can be totally reduced to methane. It is widely employed as an initiator in the dehydrochlorination of chloroethanes at 400—600°C ... 

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). 

Hexachloroethane is formed in minor amounts in many industrial chlorination processes designed to produce lower chlorinated hydrocarbons, usually via a sequential chlorination step. Chlorination of tetrachloroethylene, in the presence of ferric chloride, at 100—140°C is one convenient method of preparing hexachloroethane (142). Oxychlorination of tetrachloroethylene, using a copper chloride catalyst (143) has also been used. Photochemical chlorination of tetrachloroethylene under pressure and below 60°C has been studied (144) and patented as a method of producing hexachloroethane (145), as has recovery of hexachloroethane from a mixture of other perchlorinated hydrocarbon derivatives via crystalH2ation in carbon tetrachloride. Chlorination of hexachlorobutadiene has also been used to produce hexachloroethane (146). 

Under polymerisation conditions, the active center of the transition-metal haHde is reduced to a lower valence state, ultimately to which is unable to polymerise monomers other than ethylene. The ratio /V +, in particular, under reactor conditions is the determining factor for catalyst activity to produce EPM and EPDM species. This ratio /V + can be upgraded by adding to the reaction mixture a promoter, which causes oxidation of to Examples of promoters in the eadier Hterature were carbon tetrachloride, hexachlorocyclopentadiene, trichloroacetic ester, and hensotrichloride (8). Later, butyl perchlorocrotonate and other proprietary compounds were introduced (9,10). 

The submitters report that both l,4-diazabicyclo[2.2.2]octane and triethylamine have been used to catalyze this decomposition. Tri-ethylamine was less satisfactory as a catalyst because of its relatively rapid reaction with the solvent, carbon tetrachloride, to form triethylamine hydrochloride and because of difficulty encountered in separating triethylamine from the dicarbonate pi oduct. The 1,4-diazabicyclo-[2.2.2]octane was efficiently separated from the dicarbonate product by the procedure described in which the crude product was washed with very dilute aqueous acid. 

Polyethylene can be chlorinated in solution in carbon tetrachloride or in suspension in the piescnce ot a catalyst. Below 55-60% chlorine, it is more stable and more compatible with many polymers, especially polyvinyl chloride, to which it gives increased impact strength. The low pressure process copolymerizes polyethylene with propylene and butylene to increase its resistance to stress cracking. Copolymerization with vinyl acetate at high pressure increases flexibility, resistance to stress cracking, and seal ability of value to the food industry. 

Carbon disulfide is primarily used to produce rayon and cellophane (regenerated cellulose). CS2 is also used to produce carbon tetrachloride using iron powder as a catalyst at 30°C ... 

Carbon tetrachloride is used to produce chlorofluorocarbons by the reaction with hydrogen fluoride using an antimony pentachloride (SbCls) catalyst ... 

Zinc chloride is also a catalyst for a liquid-phase process using concentrated hydrochloric acid at 100-150°C. Hydrochloric acid may be generated in situ by reacting sodium chloride with sulfuric acid. As mentioned earlier, methyl chloride may also be produced directly from methane with other chloromethanes. However, methyl chloride from methanol may be further chlorinated to produce dichloromethane, chloroform, and carbon tetrachloride. 

Oxa-4,5-benzotricyclo[4.1.0.02-7]heptene was readily converted to 1-benzoxepin (1) on treatment with silver(I) perchlorate. Dicarbonylrhodium chloride dimer or j3-allylpalladium chloride dimer can also be used as catalyst. Thermolysis of the starting material in carbon tetrachloride solution gives 2a,7b-dihydrocyclobuta[6]benzofuran (2) as a new isomer. Depending on the temperature the proportion of 2 varies from 50% (150°C) to 100% (225°C).110... 

Carbon tetrachloride-hydrogen sulfide-water ternary system, 49, 51, 52 Carboniuin ion polymerization, 158 Carboxylic groups initiator, 174 Catalyst clathrates equilibrium, 35 Cell partition function, in calculation of thermodynamic quantities of clathrates, 26... 

The data on the determination of the number of the propagation centers on chromium oxide catalysts by the inhibition method were given in several papers water (61), carbon tetrachloride (167), and diethylamine (69) were used as inhibitors. It was found that the number of propagation centers is about 10% (61), 1% (167), and 20% (69) of the total content of chromium in the catalyst. 

The effect of catalysis by trifluoroacetic acid on chlorination in carbon tetrachloride has also been determined272. For 1,2,4,5-tetramethylbenzene, with low concentrations of catalyst, the order in catalyst is three-halves, but for toluene (which requires a higher concentration) the order is mixed three- and five-halves the indication is, therefore, that a minimum of three catalyst monomers (or one monomer and one dimer) are necessary. Since trifluoroacetic acid is very likely to be dimeric in carbon tetrachloride, the concentration of monomer is pro-... 

Catalysis by hydrogen chloride or iodine monochloride in chlorination in carbon tetrachloride has also been examined. For the chlorination of pentamethylbenzene, the reaction was first-order in both aromatic and chlorine and either three-halves, or mixed first- and second-order in hydrogen chloride, but iodine monochloride was more effective as a catalyst and the chlorination of mesitylene was first-order in iodine monochloride the activation energy for this latter reaction (determined from data at 1.2 and 25.0 °C) was only 0.4 273. 

In the literature a number of different techniques for the preparation of a-sulfo fatty acid esters can be found. There is equipment for small-scale and commercial scale sulfonation. Stirton et al. added liquid sulfur trioxide dropwise to the fatty acids dispersed or dissolved in chloroform, carbon tetrachloride, or tetrachoroethylene [44]. The molar ratio of S03/fatty acid was 1.5-1.7 and the reaction temperature was increased to 65 °C in the Final stage of sulfonation. The yield was 75-85% of the dark colored a-sulfonated acid. The esterification of the acid was carried out with either the a-sulfonic acid alone, in which case the free sulfonic acid served as its own catalyst, or with the monosodium salt and a mineral catalyst. 

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