Synthesis dichloroethylene

Dichloroethylene can be produced by direct chlorination of acetylene at 40°C. It is often produced as a by-product ia the chlorination of chloriaated compounds (2) and recycled as an iatermediate for the synthesis of more useful chloriaated ethylenes (3). 1,2-Dichloroethylene can be formed by contiauous oxychloriaation of ethylene by use of a cupric chloride—potassium chloride catalyst, as the first step ia the manufacture of vinyl chloride [75-01-4] (4). 

Dichloroethylene can be used as a low temperature extraction solvent for organic materials such as dyes, perfumes, lacquers, and thermoplastics (13—15). It is also used as a chemical intermediate in the synthesis of other chlorinated solvents and compounds (2). 

Uses Copolymerized with methyl acrylate, methyl methacrylate, vinyl acetate, vinyl chloride, or 1,1-dichloroethylene to produce acrylic and modacrylic fibers and high-strength fibers ABS (acrylonitrile-butadiene-styrene) and acrylonitrile-styrene copolymers nitrile rubber cyano-ethylation of cotton synthetic soil block (acrylonitrile polymerized in wood pulp) manufacture of adhesives organic synthesis grain fumigant pesticide monomer for a semi-conductive polymer that can be used similar to inorganic oxide catalysts in dehydrogenation of tert-butyl alcohol to isobutylene and water pharmaceuticals antioxidants dyes and surfactants. 

Uses Synthetic fibers and adhesives chemical intermediate in vinylidene fluoride synthesis production of poly(vinyl dichloroethylene) and LLl trichloroethane comonomer for food packaging, coating resins, and modacrylic fibers. 

The first total synthesis of kelsoene was achieved by Mehta and Srinivas [7, 8]. The tricyclic scaffold was established by an intermolecular [2+2]-photocycloaddition of diquinane enone rac-6 and 1,2-dichloroethylene (7) as the key step (Scheme 2). As a consequence of the steric hindrance implemented... 

Uses. 1,2-Dichloroethylene is used as a solvent for organic materials and as an intermediate in the synthesis of other chlorinated compounds it may be produced by the chlorination of acetylene but is often produced as a by-product in the manufacture of other chlorinated compounds. 

Forkert, P.G, Forkert, L., Farooqui, M. Reynolds, E.S. (1985) Lung injury and repair DNA synthesis following 1,1-dichloroethylene. Toxicology, 36, 199-214... 

Another approach to the synthesis of polyimides from chloral derivatives involves the use of dianhydrides of isomeric tetracarboxylic acids containing central carbonyl or 1,1-dichloroethylene groups and two ether bonds as the starting electrophilic compounds [31-33] (Scheme 3.8). 

Vinyl chlorides. In the presence of Ni[P(CAH5)3]4 (6, 570)5 Grignard reagents reacts stereospecifically with (E)- or (Z)-dichloroethylene to form (E)- or (Z)-l-chloro-alkencs, respectively. The reaction has been used for an efficient synthesis of the 1,3-diene 1. the sex pheromone of Lobesia botrane (equation 1). 

As shown in Figure 1.17, there are three possible dichloroethylene compounds, all clear, colorless liquids. Vinylidene chloride forms a copolymer with vinyl chloride used in some kinds of coating materials. The geometrically isomeric 1,2-dichloroethylenes are used as organic synthesis intermediates and as solvents. Trichloroethylene is a clear, colorless, nonflammable, volatile liquid. It is an excellent degreasing and dry-cleaning solvent and has been used as a household solvent and for food extraction (for example, in decaffeination of coffee). Colorless, nonflammable liquid tetrachloroethylene has properties and uses similar to those of trichloroethylene. Hexachloro-butadiene, a colorless liquid with an odor somewhat like that of turpentine, is used as a solvent for higher hydrocarbons and elastomers, as a hydraulic fluid, in transformers, and for heat transfer. 

As shown in Figure 16.2, there are three possible dichloroethylene compounds, all clear, colorless liquids. Vinylidene chloride forms a copolymer with vinyl chloride, used in some kinds of coating materials. The geometrically isomeric 1,2-dichloroethylenes are used as organic synthesis intermediates and as solvents. 

Chiral cyclohexenones have been frequently employed in intermolecular [2 + 2]-photocydoaddition reactions directed towards natural product synthesis. A further case in point is the reaction of cydohexenone 32 with trans-1,2-dichloroethylene... 

The second case study involved PBTD modeling of toxicodynamic interactions between trichloroethylene (TCE) and 1,1-dichloroethylene (DCE) regarding their binding and depletion of hepatic glutathione (GSH) in relation to the intrinsic hepatic GSFI synthesis (El-Masri et al. 1996b), which is a protective mechanism... 

The preparation of orthoformic acid esters from chloroform and alkali metal alkoxides is a long known procedure, " which can be performed under phase transfer catalysis. If small amounts of alcohol are present in the phase-catalyz process, cyclopropanes (372 Scheme 67) can be produced by aHHifinn of dichlorocarbene to l,2-dialkoxy-l,2-dichloroethylenes, which are thought to be intermediates. " Al-kenes of this kind, e.g. (373 equation 176), have been observed as byproducts in the synthesis of tri-r-butylorthoformate from chlorodifluoromethane or dichlorofluoromethane and potassium r-butoxide. Trimethoxyacetonitrile was prepared from trichloroacetonitrile and sodium methoxide. ... 

The coupling reaction between sp - and ip-carbon centers is stereospecific with (Z)- and ( )-vinylic bromides. For example, (Z)-methyl-3-bromoacrylate reacts with 1 -hexyne in the presence of a Pd catalyst to form the (Z)-enzyne as the only product (Scheme 24). This technique has also been applied in the stereoselective synthesis of 1 -chloroenynes from (Z)-dichloroethylene (Scheme 25). Trimethylsilylacetylene affords the 2 1 coupled endiyne product (37) in a stereospecific manner on coupling with geometrical isomers of 1,2-dichloroethylene (Scheme 26). In the absence of copper(I) iodide, no reaction occurs. ... 

An alternative synthesis of 2,3-dihydro-1,4-dithiin employs an unsaturated dithiolate ion. Thus, c/5-l,2-ethylenedithiolate, generated from 1,2-dichloroethylene as shown, reacts with 1,2-dibromo-ethane to give the desired compound (Scheme 7) <91SM2093). 

Bulk polymerization of vinylene carbonate (VCA) initiated by 60Co y-rays was studied at 30°-110°C at a constant dose rate of 1 - 105 rad/hr. An overall activation energy of 5.0 kcal/mole and a maximum reaction rate of 1 10 3 mole/l-sec were obtained. As has been reported, purification of the monomer is a crucial point because inhibiting impurities are formed during the synthesis. From experiments with chlorine-substituted ethylene and vinylene carbonates, we tentatively conclude that, in addition to mono- and dichloroethylene carbonate, dichloro-vinylene carbonate is mainly responsible for the inhibition. The copolymerization behavior of VC A with some chlorine-substituted olefins was studied. Chlorotrifluoroethylene (CTFE) is an especially suitable comonomer the reactivity ratios found were rVCA = 0.42 and rCXFE = 0.48. 

The properties of polynaphthoylenebenzimidazoles can be affected by the introduction of 1,1-dichloroethylene and 1,1-dibromoethylene groupings into the macromolecules using the application of the corresponding bis(naphthalic anhydrides) [148-151, 196]. Synthesis of polynaphthoylenebenzimidazoles containing 1,1-dichloroethylene and 1,1-dibromoethylene bridging groups [114,148-151,196] was carried out in m-cresol using benzoic acid as a catalyst ... 

Aryl iodides, bromides, and inflates are used for Sonogashira coupling. But so far few smooth reactions of aryl chlorides with alkynes have been reported. On the other hand, smooth coupling takes place with alkenyl chlorides. The Pd-catalyzed reaction of 1-alkynes with alkenyl chlorides, which are inert in many other Pd-catalyzed reactions, proceeds smoothly without special activation of the chlorides. For example, cw-l,2-dichloroethylene (31) can be coupled with 1-alkynes smoothly, and the coupling has wide synthetic applications, particularly for the synthesis of enediyne structures [30]. The reaction of 31 with two different 1-alkynes is extensively used for construction of highly strained enediyne structures present in naturally occurring anticancer antibiotics such as espermicin and calichemicin [31,32]. The asymmetric (Z)-enediyne 34 can be prepared by a one-pot reaction of 31 with two different 1-alkynes 32 and 33. Similarly the asymmetric ( )-enediyne 37 was obtained in a one-pot reaction of 1-alkynes 33 and 23 with 1,2-dichloroethylene 35. 

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