382-21-8

-

-

-

-

The invention discloses a method for synthesizing fluoroisobutylene by taking hexafluoropropylene as an initial raw material. The method comprises the following steps: (1) gas phase addition reaction: in the presence of a block catalyst, hexafluoropropylene and fluoromethane CHFXY (X, Y = F or H) are subjected to gas phase addition to obtain (CF3)2CFCHXY, and (2) dehydrofluorination reaction: in the presence of a dehydrofluorination catalyst, the (CF3)2CFCHXY as a raw material is subjected to dehydrofluorination reaction to obtain (CF3)2C = CXY. The block catalyst and the dehydrofluorination catalyst in the invention have the characteristics of high activity and long service life, and can be used for high-efficiency and gas-phase continuous cycle production of fluoroisobutylene.

A new method is described for producing 3,3,3-trifluoroethyl isocyanate from perfluoroisobutene (PFIB). Isocyanate was used for synthesis of carbamates and ureas. A series of trifluoroethyl-substituted ureas has been tested in the National Cancer Institute (NCI, Bethesda, USA) by the NCI-60 DTP Human Tumor Cell Line Screening Program at a single high dose (10-5 M). The moderate anticancer activity was shown against some types of cancer on the individual human cell lines for leukemia, non-small cell lung cancer and renal cancer.

A process for depolymerizing fluoropolymers includes continuously feeding a solid fluoropolymer, in particulate form, into a horizontal cylindrical first reaction zone. The fluoropolymer particles enter the first reaction zone at one end. Within the first reaction zone, a central axle from which protrudes at least one paddle, continuously rotates. The rotating paddle serves to advance the fluoropolymer particles along the reaction zone while agitating them. As the fluoropolymer particles pass along the reaction zone, they are subjected to an elevated temperature, thereby depolymerizing the fluoropolymer into a fluoro-containing compound-rich gas phase. A residual solids phase is withdrawn at the other end of the first reaction zone, as is the gas phase. Optionally, the gas phase is passed through a second reaction zone which is also at an elevated temperature. The gas phase is quenched, thereby to recover the fluoro-containing compounds as gaseous products.

The present invention relates to the pyrolysis of hydrochlorofluorocarbons to form fluoromonomers such as tetrafluoroethylene, the pyrolysis being carried out in a reaction zone lined with nickel and mechanically supported by a jacket of other corrosion resistant metal, the nickel lining providing an improved yield of valuable reaction products.

A simple and practical method has been developed for the synthesis and characterization of several interesting classes of volatile organofluorine compounds from fluorophosphonium salts via their in situ generated corresponding ylides. The fluorinated phosphonium ylides react with hexafluoroacetone in DMF to generate perfluoroisobutylene, whereas in the presence of bromine or iodine containing electrophiles, tetrafluoroethylene, perfluoro-2-butene, perfluorocyclobutane, and 1H-heptafluoropropane are obtained.

Processes for producing a fluoromonomer from a fluoropolymer, among which one that can be carried out more simply is a process wherein thermal decomposition of a fluoropolymer is preformed by means of a rotary kiln (5) so as to produce a fluoromonomer, the process comprising feeding a fluoropolymer and steam (3) into a rotary kiln and heating the fluoropolymer.

Mono-, di- and tri-substituted fluorine-containing α-oxides have been shown to enter into reactions with trialkyl phosphites which proceed through cleavage of the C-C and C-O bonds in the epoxide ring.The trialkoxyphosphorus ylides II, V, VII and VIII were obtained from the epoxides I, IV, VII and XVI.Triethoxyfluorocarbonylfluorophosphorane (IIIb) has been isolated and characterized.Further conversions of IIIb have been studied and the formation of trialkoxyphosphorus ylides XXIV containing a fluorine atom in the position α to the phosphorus atom has been noted.It has been shown that when propylene oxide reacts with triethyl phosphite, vinyl ethers are obtained through the intermediate formation of tetrafluoroethylidenetriethoxyphosphorane (XX).

Unlike its hydrocarbon counterpart, perfluoro-2-(trifluoromethyl)propene is a highly reactive compound.It participates in both heterolytic and homolytic reactions.It readily reacts with nucleophiles and sluggishly with electrophiles.It reacts as well with common organic solvents, such as dimethylformamide, ethanol and others.In this communication we describe its reactions with trifluoromethylthiocopper, sulfur trioxide and tributyltin cyanide, the mechanism of formation of the various products and their mass spectral data.

The title perfluoro-α-lactam (1) was found to react with N,N-dimethylformamide to give initially a betaine (2) which undergoes ring enlargement to produce the isomeric 2-dimethylamino-3,4,4-tri(perfluoroalkyl)substituted 5-oxazolidone (3).Related betaines were also obtained on reaction of 1 with pyridine, quinoline, benzalaniline, and p-dimethylaminobenzaldehyde.

The thermal stability of perfluorinated iodides depends on their structure and decreases in the order of RFCF2CF2I>RFCF2CF(CF3)I>RFOCF(CF3)I=RFCF2C(CF3)2I.The major decomposition path consists of the elimination of an unsaturated compound (CF2=CF2, CF2=CF-CF3, O=CF-CF3, CF2=C(CF3)2, respectively) with concomitant formation of RFI.The highest selectivities were found for tertiary iodides and 2-iodo-3-oxaalkanes, whose decomposition is virtually irreversible.UV-photolysis of the iodo-compounds gave the same products as the thermolysis reactions.

-

-

Two novel perfluoro-tert-alkyl iodides CF3(CF2)n+1C(CF3)2I have been obtained from F-alkenes CF3(CF2)n-CF=C(CF3)2 (n = 0 and 1) by formal additions of iodine fluoride; these required substantial alterations of known procedures.The F-tert-alkyl iodides are the most reactive alkyl halides known so far, and they are also very toxic.The following types of reactions have been studied: (a) Nucleophilic attack of anions at the iodine, leading to F-alkenes, (b) elimination of iodine fluoride, caused by metals or metal complexes, (c) pyrolysis, to give very selectively F-isobutene and n-perfluoroalkyl iodides, (d) photolysis, and (e) thermally induced insertions into the carbon-iodine bond.Screening results on the inhalation toxicity of the iodides and of some other fluoro-compounds are also reported.

-

-

-

-

-

-

-

-

-