2.2- Dichloroethane

2-Dichloroethane (ethylene dichloride) is used in the production of vinyl chloride. The odor threshold in water is 20 mg L-1 and has been shown to cause cancer in rats and mice. 

1-Dichloroethane is used as a precursor material for the production of the tri-chloroethanes. From numerous production routes, the catalytical addition of HCl to vinylchloride is industrially used 

Data were last reviewed in lARC (1979) and the compound was classified in lARC Monographs Supplement 7 (1987a). 

107-06-2 Chem. Abstr. Name-. 1,2-Dichloroethane lUPAC Systematic Name-. 1,2-Dichlorocthane Synonym Ethylene dichloride 

2 Structural and molecular formulae and relative molecular mass 

World production capacities in 1988 for 1,2-dichloroethane have been reported as follow s (thousand tonnes) North America, 9445 western Europe, 9830 Japan, 3068 and other, 8351 (Snedecor, 1993). Production in the United States has been reported as follows (thousand tonnes) 1983, 5200 1990, 6300 1991, 6200 1992, 6900 1993, 8100 (United States National Library of Medicine, 1997). The total aimual production in Canada in 1990 was estimated to be 922 thousand tormes more than 1000 thousand tonnes were produced in the United Kingdom in 1991 (WHO, 1995). 

Current occupational exposure to 1,2-dichloroethane in North America occurs predominantly during the manufacture of other chemicals, such as vinyl chloride, where 1,2-dichloroethane is used as an intermediate. In a 1982 National Occupational Exposure Survey by the United States National Institute for Occupational Safety and Health (NIOSH), 28% of employees working with adhesives and solvents were exposed to 1,2-dichloroethane, while between 5 and 9% of workers were exposed to the substance in the medicinals and botanicals, biological products, petroleum refining and organic chemicals industries, and in museums and art galleries (United States Department of Labor, 1989). 

Cleansing agent degreaser solvent for plastics, oils, and fats grain fumigant chemical intermediate formerly used as an anesthetic 

Toxicology. At high concentrations 1,1-dichloroethane causes central nervous system depression. 

There have been no reported cases of human overexposure by inhalation. In the past, 

1- dichloroethane was used as an anesthetic at levels of approximately 25,000ppm. Use was discontinued when it was discovered that cardiac arrhythmias might be induced. Cardiovascular toxicity has not been reported in animals after exposure. 

No bistopathological alterations were noted in tbe liver, kidneys, or lungs of male mice that ingested up to 2500mg/liter 1,1-dicbloroetbane in drinking water for 52 weeks.  

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BrCHi CHjBr. A colourless liquid with a sweet odour, m.p. 10°C, b.p. 132°C. Manufactured by passing ethene through bromine or bromine and water at about 20 C. Chemical properties similar to those of 1,2-dichloroethane when heated with alkali hydroxides, vinyl bromide is formed. Used extensively in petrols to combine with the lead formed by the decomposition of lead tetraethyl, as a fumigant for stored products and as a nematocide. 

The hexahydrate fonns colourless crystals, m.p. 44 C (104 C when anhydrous), b.p. 126 C. Made by the action of alcoholic ammonia on 1,2-dichloroethane, piperazine is used in human and veterinary medicine in the treatment of threadworm and roundworm infestations. 

The most common way to describe a molecule by its internal coordinates is the so-called Z-matrix. Figure 2-92 shows the Z-matrix of 1,2-dichloroethane. 

Figure 2-91. Internal coordinates of 1,2-dichloroethane bond lengths and r2, bond angle a, and torsion angle r.

Figure 7.13 reprinted with permission from Jorgensen W L, R C Binning Jr and B Bigot. Structures md Properties of Organic Liquids u-Butane and 1,2-Dichloroethane and Their Conformational Equilibria. The Journal of the American Chemical Society 103 4393-4399. 1981 American Chemical Society. 

Method I. This procedure is used for most ketone reactions. A representative example is the reductive amination of cyclopenta-none [P2P] with hexamethyleneimine [MeNHa] Hexamethyl-eneamine (I.Og, lOmmol) and cylclopentanone (0.84g, lOmmol) were mixed in 1,2-dichloroethane (35mL) and then treated with... 

To a suspension of AICI3 (89 g, 0.67 mol) in 1,2-dichloroethane (600 ml) chloroacctyl chloride (56ml, 0.70mol) was added dropwise at 0°C. After the addition was complete the mixture was kept at ambient temperature for 15 min, at which lime l-(2,2-dimethylpropanoyl)indole (30 g, 0.15 mol) was added over 3 h. After completion of the addition, the mixture was stirred for 15 min and then poured into ice-cold water. The mixture was extracted with 1,2-dichloroethane. The extract was washed with water (3 x) and aq. 5% NaHCOj (3 X), dried (Na2S04) and concentrated in vacuo. The residue was... 

Methyl-5-aminothia2ole-4-carboxylic acid is diazotized with isoamyl nitrite in the presence of furan in 1.2-dichloroethane to give a mixture of products 163 (53%), 164 (33%). 165 (11%), and 166 (3%) (Scheme 104) (334). This reactivity experiment was carried out to examine the possibility of the occurrence of 4,5-dehydrothiazole (hetaryne). Hetaryne intermediates seem not to be involved as an intermediate in the reaction. The formation of 163 through 166 can be rationalized in terms of the intermediacy of 166a. 

Nucleophilic substitution is one of a variety of mechanisms by which living systems detoxify halogenated organic compounds introduced into the environment Enzymes that catalyze these reactions are known as haloalkane dehalogenases The hydrolysis of 1 2 dichloroethane to 2 chloroethanol for example is a biological nude ophilic substitution catalyzed by a dehalogenase... 

This stage of the reaction proceeds by a mechanism that will be discussed in Chapter 20 Both stages are faster than the reaction of 1 2 dichloroethane with water in the absence of the enzyme... 

IR spectroscopy is an inherently faster method than NMR and an IR spectrum is a superposition of the spectra of the various conformations rather than an average of them When 1 2 dichloroethane is cooled below its freezing point the crystalline matenal gives an IR spectrum consistent with a single species that has a center of symmetry At room temperature the IR spec trum of liquid 1 2 dichloroethane retains the peaks present in the solid but includes new peaks as well Explain these observations... 

A hydroxyl group is a very powerful activating substituent and electrophilic aro matic substitution m phenols occurs far faster and under milder conditions than m ben zene The hrst entry m Table 24 4 for example shows the monobrommation of phenol m high yield at low temperature and m the absence of any catalyst In this case the reac tion was carried out m the nonpolar solvent 1 2 dichloroethane In polar solvents such as water it is difficult to limit the brommation of phenols to monosubstitution In the fol lowing example all three positions that are ortho or para to the hydroxyl undergo rapid substitution... 

The principle of headspace sampling is introduced in this experiment using a mixture of methanol, chloroform, 1,2-dichloroethane, 1,1,1-trichloroethane, benzene, toluene, and p-xylene. Directions are given for evaluating the distribution coefficient for the partitioning of a volatile species between the liquid and vapor phase and for its quantitative analysis in the liquid phase. Both packed (OV-101) and capillary (5% phenyl silicone) columns were used. The GG is equipped with a flame ionization detector. 

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