303-04-8

The invention discloses a gas-phase continuous synthesis method of cis-1,1,1,4,4,4-hexafluoro-2-butene. The method includes the following preparation steps: (1) mixing 1,1,1-trifluorotrichloroethane with hydrogen for a reaction so as to obtain a product stream I, transferring the product stream I to a first separation tower, absorbing the mixed product stream obtained at the tower top through a HCl absorption tower, and returning the mixed product stream to a reactor I so as to obtain 1,1,1,4,4,4-hexafluoro-2,3-dichloro-2-butene in the tower kettle; (2) transferring the tower kettle liquid obtained in the step (1) to a preheater II, introducing hydrogen at the same time, performing mixing and preheating until 200 DEG C, transferring the preheated mixture to a reactor II, performing a hydrodechlorination reaction under the action of a catalyst so as to obtain a product stream II, transferring the product stream II to a second separation tower, and circulating the tower kettle liquid tothe reactor II; and (3) transferring the tower top product obtained in the step (2) to a preheater III, performing preheating to 260 DEG C, transferring the preheated product to a reactor III, performing an isomerization reaction under the action of a catalyst so as to obtain a product stream III, transferring the product stream III to a third separation tower so as to obtain cis-1 1,1,4,4,4-hexafluoro-2-butene in the tower kettle.

The invention discloses a preparation method of 1,1,1,4,4,4-hexafluoro-2-butene. The method comprises the following preparation steps: (1) reacting a raw material 1,1,1-trifluorotrichloroethane with hydrogen under the action of a catalyst to obtain a first product 1,1,1,4,4,4-hexafluoro-2,3-dichloro-2-butene; (2) reacting the 1,1,1,4,4,4-hexafluoro-2,3-dichloro-2-butene obtained in step (1) with hydrogen under the action of a catalyst to obtain a second product 1,1,1,4,4,4-hexafluoro-2-chloro-2-butene; (3) carrying out a gas-phase dehydrochlorination reaction on the 1,1,1,4,4,4-hexafluoro-2-chloro-2-butene obtained in step (2) under the action of a catalyst to obtain a third product hexafluoro-2-butyne; and (4) carrying out a selective hydrogenation reaction on the hexafluoro-2-butyne under the action of a catalyst to obtain the final product 1,1,1,4,4,4-hexafluoro-2-butene. The preparation method has the advantages of conventional and easily obtained raw material, simple process, convenience in operation, environmentally-friendly preparation process, small pollution, and suitableness for industrial production, and the prepared 1,1,1,4,4,4-hexafluoro-2-butene has an excellent selectivity and an excellent conversion rate.

The invention relates to a method for preparing 1,1,1,4,4,4-hexafluoro-2-butene. The method for preparing the 1,1,1,4,4,4-hexafluoro-2-butene comprises the following steps: (1) carrying out a reactionon 1,1,1-trifluorochloroethane and/or 1,1,1-trifluoro-2,2-dichloroethane used as raw materials in lights by using chlorine as a catalyst to generate 1,1,1,4,4,4,4-hexafluoro-2,2,3,3-tetrachlorobutane; (2) dechlorinating the 1,1,1,4,4,4,4-hexafluoro-2,2,3,3-tetrachlorobutane obtained in step (1) with zinc powder to prepare 1,1,1,4,4,4-hexafluoro-2,3-dichlorobutene; and (3) reacting the 1,1,1,4,4,4-hexafluoro-2,3-dichlorobutene obtained in step (2) with hydrogen in the presence of a hydrogenation catalyst to obtain the 1,1,1,4,4,4-hexafluoro-2-butene. The method has the advantages of easily available catalyst and raw materials, production of the final product from the above intermediate in multiple paths, and high yield.

The invention discloses a preparation method of 1,1,1,2,4,4,4-heptafluoro-2-butene. The method uses hexachlorobutadiene and hydrogen fluoride as raw materials and uses a chromium-based catalyst as a fluorine-chlorine exchange catalyst to form the 1,1,1,2,4,4,4-heptafluoro-2-butene under gas phase conditions through a plurality of gas-phase catalytic reactions. Compared with the prior art, the preparation method of the 1,1,1,2,4,4,4-heptafluoro-2-butene provided by the invention has the following advantages: 1, the gas phase fluorination method adopted in the method is a cycle fluorination method, has less three industrial wastes (waste water, waste gases and solid waste), and greatly reduces the production costs; 2, the method can realize rapid and multiple-cycle fluorination, improve a product yield, and have simple separation and purification of the product; and 3, the method has the advantages of cheap raw materials, convenient sources and simple operation, and is suitable for industrialized production.

Disclosed is a process for the preparation of fluorine-containing olefins comprising contacting a chlorofluoroalkane with hydrogen in the presence of a catalyst at a temperature sufficient to cause replacement of the chlorine substituents of the chlorofluoroalkane with hydrogen to produce a fluorine-containing olefin. Also disclosed are catalyst compositions for the hydrodechlorination of chlorofluoroalkanes comprising copper metal deposited on a support, and comprising palladium deposited on calcium fluoride, poisoned with lead and reducing the in the presence or absence of a dehydrochlorination catalyst under conditions effective to form a product stream comprising cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336).

Disclosed is a process for preparing cis-1,1,1,4,4,4-hexafluoropropene comprising the steps of (a) reacting CCl4 with a compound having the formula CF3CX═CXH, where each X is independently halogen or hydrogen, to form a compound having the formula CF3CXClCXHCCl3; (b) fluorinating the compound formed in step (a) to form a compound having the formula CF3CXHCXHCF3; (c) converting the compound formed in step (b) by a reaction selected from the group consisting of dehydrohalogenation, dehalogenation and both reactions, to form a compound having the formula CF3C≡CCF3; and (d) catalytically reducing the compound formed in step (c) with hydrogen to form the compound having the formula:

A reductive dimerization process of 1,1,1-trifluoro, 2,2,2-trichloroethane (CFC-113a) with hydrogen, with formation of 1,1,1,4,4,4-hexafluoro-2,2,3,3-tetrachlorobutane and 1,1,1,4,4,4-hexafluoro-2,2-dichlorobutene, and mixtures thereof, wherein the catalyst is constituted by metal ruthenium supported on graphitized carbon obtainable by treatment of the carbon at temperatures higher than 2000° C., in inert gas, or aluminum fluoride having an high surface area.

1,1,1-Trichloro-2,2,2-trifluoroethane or 1,1-dichloro-1,2,2,2-tetrafluoroethane, both of which have CF3 group, dimerizes over supported Ni catalysts at an elevated temperature (723 K) into corresponding C4-compounds in good to moderate yields.

CW CO2 photosensitized (SF6) homogeneous decomposition of 1-bromo-1-chloro-2,2,2-trifluoroethane yields various halobutenes and haloethanes.The former are suggested to arise from a sequence of C-Br cleavage, radical recombinations to halobutanes and conse

Direct chlorination of 2-(2H-hexafluoropropyl)-tetrahydrofuran 1 gave high yield of 2-(2-chlorohexafluoropropyl)-pentachloro-2,5-dihydrofuran 2.Bromination of 1 gave very complex mixture of products, from which three compounds, viz. 2-bromo-5-(2H-hexafluoropropyl)-furan 3, 3-bromo-5-(2Hhexafluoropropyl)-furan 4, and 2,4-dibromo-5-(2H-hexafluoropropyl)-furan 5 were isolated.Exchange fluorination of 2 with dry KF at 240 - 300 deg led to a stepwise substitution of fluorines for chlorines to give mixtures of chloro-fluoro-2-(2-chlorohexafluoropropyl)-dihydrofurans 7,8,9 and 10 together with small amounts of 2-(2-chlorohexafluoropropyl)-3,4,5-trichlorofuran 6.Exchange fluorination of 3,4-dihalo-2,2,5,5-tetrafluoro-2,5-dihydrofurans 11a and 11b led to a substitution of fluorine for one vinylic halogen to give 3-halo-2,2,4,5,5-pentafluoro-2,5-dihydrofurans 12a and 12b in good yields.Compounds 2 - 12 were characterized by n.m.r., m.s., and i.r. spectroscopy and elemental analysis.