A process for producing E-1,1,1,4,4,4-hexafluorobut-2-ene comprises contacting 1,1,2,4,4-pentachlorobuta-1,3-diene with hydrogen fluoride in the vapor phase in the presence of a fluorination catalyst. A process for producing Z-1,1,1,4,4,4-hexafluorobut-2-ene further comprises contacting E-1,1,1,4,4,4-hexafluoro-2-butene with chlorine in the presence of a catalyst to produce 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane, followed by reaction with base to produce 1,1,1,4,4,4-hexafluoro-2-butyne, and subsequently hydrogenating hexafluoro-2-butyne to produce Z-1,1,1,4,4,4-hexafluoro-2-butene.

A process for producing E-1,1,1,4,4,4-hexafluorobut-2-ene comprises contacting 1,1,2,4,4-pentachlorobuta-1,3-diene with hydrogen fluoride in the vapor phase in the presence of a fluorination catalyst. A process for producing Z-1,1,1,4,4,4-hexafluorobut-2-ene further comprises contacting E-1,1,1,4,4,4-hexafluoro-2-butene with chlorine in the presence of a catalyst to produce 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane, followed by reaction with base to produce 1,1,1,4,4,4-hexafluoro-2-butyne, and subsequently hydrogenating hexafluoro-2-butyne to produce Z-1,1,1,4,4,4-hexafluoro-2-butene.

Disclosed are compositions comprising HCFC-243db, HCFO-1233xf, HCFC-244db and/or HFO-1234yf and at least one additional compound. For the composition comprising 1234yf, the additional compound is selected from the group consisting of HFO-1234ze, HFO-1243zf, HCFC-243db, HCFC-244db, HFC-245cb, HFC-245fa, HCFO-1233xf, HCFO-1233zd, HCFC-253fb, HCFC-234ab, HCFC-243fa, ethylene, HFC-23, CFC-13, HFC-143a, HFC-152a, HFC-236fa, HCO-1130, HCO-1130a, HFO-1336, HCFC-133a, HCFC-254fb, CHFCHCl, HFO-1141, HCFO-1242zf, HCFO-1223xd, HCFC-233ab, HCFC-226ba, and HFC-227ca. Compositions comprising HCFC-243db, HCFO-1233xf, and/or HCFC-244 db are useful in processes to make HFO-1234yf. Compositions comprising HFO-1234yf are useful, among other uses, as heat transfer compositions for use in refrigeration, air-conditioning and heat pump systems.

There is provided a method for producing chlorofluorobutane (CFB) by forming chlorinated butadiene by dimerizing trichloroethylene (TCE) and fluorinating hydrogen atoms of the chlorinated butadiene. Trichloroethylene (TCE) is dimerized by using a dimer represented by the following formula (1) as a solvent and in the presence of a free radical generating agent at a temperature of 100 C. or higher. Hexachlorobutadiene (C.sub.4Cl.sub.6) is produced from the above dimer by chlorination and dehydrochlorination reaction, and further, the chlorofluorobutane (CFB) is produced by fluorinating the hexachlorobutadiene.

##STR00001##

There is provided a method for producing chlorofluorobutane (CFB) by forming chlorinated butadiene by dimerizing trichloroethylene (TCE) and fluorinating hydrogen atoms of the chlorinated butadiene. Trichloroethylene (TCE) is dimerized by using a dimer represented by the following formula (1) as a solvent and in the presence of a free radical generating agent at a temperature of 100 C. or higher. Hexachlorobutadiene (C.sub.4Cl.sub.6) is produced from the above dimer by chlorination and dehydrochlorination reaction, and further, the chlorofluorobutane (CFB) is produced by fluorinating the hexachlorobutadiene.

##STR00001##

A process for producing E-1,1,1,4,4,4-hexafluorobut-2-ene comprises contacting 1,1,2,4,4-pentachlorobuta-1,3-diene with hydrogen fluoride in the vapor phase in the presence of a fluorination catalyst. A process for producing Z-1,1,1,4,4,4-hexafluorobut-2-ene further comprises contacting E-1,1,1,4,4,4-hexafluoro-2-butene with chlorine in the presence of a catalyst to produce 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane, followed by reaction with base to produce 1,1,1,4,4,4-hexafluoro-2-butyne, and subsequently hydrogenating hexafluoro-2-butyne to produce Z-1,1,1,4,4,4-hexafluoro-2-butene.

A process for producing E-1,1,1,4,4,4-hexafluorobut-2-ene comprises contacting 1,1,2,4,4-pentachlorobuta-1,3-diene with hydrogen fluoride in the vapor phase in the presence of a fluorination catalyst. A process for producing Z-1,1,1,4,4,4-hexafluorobut-2-ene further comprises contacting E-1,1,1,4,4,4-hexafluoro-2-butene with chlorine in the presence of a catalyst to produce 2,3-dichloro-1,1,1,4,4,4-hexafluorobutane, followed by reaction with base to produce 1,1,1,4,4,4-hexafluoro-2-butyne, and subsequently hydrogenating hexafluoro-2-butyne to produce Z-1,1,1,4,4,4-hexafluoro-2-butene.