Chlorotrifluoroethylene reaction

Chlorotrifluoroethylene, reaction with aqueous sodium cyanide to form 3-chloro-2,2,3-trifluoropropionic acid, 11... 

Chloro-2,2,3-trifluoropropionic acid has been prepared by permanganate oxidation of 3-chloro-2,2,3-trifluoropropanol which is one of the telomerization products of chlorotrifluoroethylene with methanol. The present procedure is a modification of one reported earlier and is undoubtedly the method of choice for making propionic acids containing 2 fluorine atoms, i.e., 2,2,3,3-tetrafluoropropionic acid, 3,3-dichloro-2,2-difluoropropionic acid, and 3-bromo-2,2,3-trifluoropropionic acid. When preparing 2,2,3,3-tetrafluoropropionic acid from tetrafluoroethylene, it is desirable to use an additional 50 ml. of acetonitrile and externally applied heat to initiate the reaction. 

A -Halogenated compounds such as iV-chlorotnfluoroacetamide, A -chloro-imidosulfuryl fluonde and N N dichlorotnfluoromethylamine add across C=C bonds to form saturated amides [14] tmidosulfury I fluorides [15] and amines [16], respectively Allylic halogenation also occurs with the use of A-bromo- or A-chIo roperfluoroamides The primary amine A,A-dichlorotrifluororaethylamine selectively affords 11 or 2 1 adducts with either tetrafluoroethylene or chlorotrifluoroethylene [16] (equation 7) The reaction mechanism is believed to involve thermal free radicals, with control achieved principally by reaction temperature The 1 1 adduct is formed even in the presence of a large excess of olefin... 

Perfluoroisobutylene undergoes cycloadditions with azides only at elevated temperatures, the reaction can lead to subsequent loss of nitrogen [6] (equation 4) In another high-temperature reaction, chlorotrifluoroethylene undergoes cy cloaddition with the azomethineylide generated from the thermal electrocyclic nng opening of an azindine, a reaction that contributes to a good overall synthesis of 3,4-difluoropyrroles [7] (equation 5)... 

The synthesis of 2-chloro-2,3,3-trifluorocyclobutyl acetate illustrates a general method of preparing cyclobutanes by heating chlorotrifluoroethylene, tetrafluoroethylene, and other highly fluorinated ethylenes with alkenes. The reaction has recently been reviewed.11 Chlorotrifluoroethylene has been shown to form cyclobutanes in this way with acrylonitrile,6 vinylidene chloride,3 phenylacetylene,7 and methyl propiolate.3 A far greater number of cyclobutanes have been prepared from tetrafluoroethylene and alkenes 4,11 when tetrafluoroethylene is used, care must be exercised because of the danger of explosion. The fluorinated cyclobutanes can be converted to a variety of cyclobutanes, cyclobutenes, and butadienes. 

The photoinitiated reaction of 1,2-dibromo-l-chlorotrifluoroethane with chlorotrifluoroethylene gives the first two telomers (ref. 28). 

With chlorotrifluoroethylene the following peroxidation reaction was iderrtified ... 

Many vinyl monomers were reported to have been grafted onto fluoropolymers, such as (meth)acrylic acid and (meth)acrylates, acrylamide, acrylonitryl, styrene, 4-vinyl pyridine, N-vinyl pyrrolidone, and vinyl acetate. Many fluoropolymers have been used as supports, such as PTFE, copolymers of TFE with HFP, PFAVE, VDF and ethylene, PCTFE, PVDF, polyvinyl fluoride, copolymers ofVDF with HFP, vinyl fluoride and chlorotrifluoroethylene (CTFE). The source of irradiation has been primarily y-rays and electron beams. The grafting can be carried out under either direct irradiation or through the use of preliminary irradiated fluoropolymers. Ordinary radical inhibitors can be added to the reaction mixture to avoid homopolymerization of functional monomers. 

Multinuclear NMR spectroscopy is being used increasingly to study catalytic reactions. In order for such studies to be possible, all contact betv een the sample solutions and the metal part of the cell body has to be avoided because of possible catalytic effects. All materials in contact vith the sample solution have to be chemically inert and nonmetallic quartz, glass, PTFE, Vespel (polyimide polymer, Dupont de Nemours), PCTFE (poly-chlorotrifluoroethylene), Viton seals, etc. 

Preference for reaction with the unlike monomer occurs when ri is less than 1. When r and T2 are approximately equal to 1, the conditions are said to be ideal, with a random (not alternating) copolymer produced, in accordance with the Wall equation. Thus, a random copolymer (ideal copolymer) would be produced when chlorotrifluoroethylene is copolymerized with tetrafluoroethylene (Table 7.1). 

Chlorotrifluoroethylene (Note 2) is introduced at such a rate, controlled by the needle valve, that it is essentially all absorbed in the reaction tube C, as indicated by the escape of little or no... 

When the required amount of chlorotrifluoroethylene has been absorbed, the reaction mixture is poured into 500 ml. of water. The product separates as a light-yellow oil, which is separated, washed with 250 ml. of water, and dried over 20 g. of anhydrous calcium chloride. From 233 g. of chlorotrifluoroethylene (2 moles), the yield of crude product is 300-315 g. (92-97%). This material is suitable for use in preparation of ethyl chlorofluoro-acetate.2 It may be fractionated through an efficient column to give 285-300 g. (88-92%) of pure chlorotrifluoroethyl ethyl ether, b.p. 87-88°, d 1-3427. 

The amount of chlorotrifluoroethylene absorbed is determined by weighing the reaction tube C and contents. A convenient alternative is to note the increase in volume of the reaction mixture, which in this case amounts to 165 ml. 

Trifluorovinyllithium was first prepared by Seyferth et al via the reaction of phenyltris(trifluorovinyl)tin and phenyllithium in ether at -40°C [111] and then more conveniently obtained via lithium-halogen exchange reaction of bromotrifluoroethylene with -butyllithium or methyllithium at -78°C [112]. Later Normant reported an inexpensive route to trifluorovinyllithium by reaction of the readily available chlorotrifluoroethylene with sec-butyllithium or terf-butyllithium [113] (Scheme 40). 

Among the fluorine-containing polymers of commercial importance, our polymer of choice was PCTFE, the homopolymer of chlorotrifluoroethylene. The reason for choosing this polymer was the assumption that the chloride group would have sufficient reactivity to allow chemical modifications (Equation 1), but, in the most likely case that such modifications were incomplete, would be inert toward the ultimate reagents and substrates when the functionalized polymers were applied in their subsequent uses in carrying out organic reactions. 

A fluorinated enol ether formed by the reaction of sodium ethoxide with chlorotrifluoroethylene is much less reactive than the starting fluoroolefin To replace the second fluonne atom, it is necessary to reflux the reaction mixture. The nucleophilic substitution proceeds by the addition-elimination mechanism [30] (equation 26). 

The apparatus consists of a simple vacuum manifold similar to that shown in Fig. 4. The vacuum manifold should be fabricated from nickel or Monel metal, with silver-soldered or Swagelok connections. Valves should be of Monel metal, and the traps and scrubber, the function of which is to remove hydrogen fluoride vapor from the C103 F product, may be constructed conveniently of poly(chlorotrifluoroethylene) (Kel-F) tubing. A nickel cylinder of 500-ml. or 1-1. capacity serves as a reaction vessel, and a 500-ml. Monel bulb or similar vessel may be used as a product receiver. The scrubber (about 1-in. o.d.) is charged with pellets of sodium fluoride prepared in a separate operation by heating sodium... 

In contrast to reaction of CF3S020X (see Eq. 100), addition of C10S02F or BrOS02F to chlorotrifluoroethylene leads to formation of two regioisomers. Reaction of bromine tris (fluorosulfate) with fluoroolefins was reported to pro-... 

The data for competition between formation of (19) and (20) in aliphatic systems are more limited, but they are only partly accounted for by the carbanionic theory. Attack on chlorotrifluoroethylene, for example, is nucleophile-dependent fluorine from the CF2 group is replaced on reaction with PhMgBr (Tarrant and Warner, 1954), PhLi (Dixon, 1956) and LiNBu2 (Yakubovich et al., 1966), while Re(CO) ... 

Addition of hydrogen bromide to chlorotrifluoroethylene may take place in two directions. Bromine may become attached to the carbon linked to two fluorines, or to the carbon with chlorine and fluorine. What is the product of the reaction ... 

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