Process for the manufacture of halocarbons and selected compounds and azeotropes with HF
View Patent ↗A liquid phase process is disclosed for producing halogenated alkane adducts of the formula CAR 1 R 2 CBR 3 R 4 (where A, B, R 1 , R 2 , R 3 , and R 4 are as defined in the specification) which involves contacting a corresponding halogenated alkane, AB, with a corresponding olefin, CR 1 R 2 ═CR 3 R 4 in a dinitrile or cyclic carbonate ester solvent which divides the reaction mixture into two liquid phases and in the presence of a catalyst system containing (i) at least one catalyst selected from monovalent and divalent copper; and optionally (ii) a promoter selected from aromatic or aliphatic heterocyclic compounds which contain at least one carbon-nitrogen double bond in the heterocyclic ring. When hydrochlorofluorocarbons are formed, the chlorine content may be reduced by reacting the hydrochlorofluorocarbons with HF. Azeotropes of CClF 2 CH 2 CF 3 with HF and azeotropes of CF 3 CH 2 CHF 2 with HF are also disclosed; as are process for producing such azeotropes.
1. A method of producing an azeotropic composition comprising HF and CF3CH2CHF2,
reacting CCl4 with CH2=CHCl to produce CCl3CH2CHCl2 and
reacting said CCl3CH2CHCl2 with HF to produce an azeotropic composition comprising HF and CF3CH2CHF2, wherein the azeotropic composition is from about
44 to 84 mole percent HF; and from about 56 to 16 mole percent CF3CH2CHF2; said composition exhibiting a relative volatility of about 1 at a pressure within the range of 5.5 kPa to 3850 kPa when the temperature is adjusted within the range of −50° C. to 130 C.
2. The method of claim 1 , wherein the step of reacting CCl4 with CH2=CHCl takes place in a dinitrile or cyclic carbonate ester solvent which divides the reaction mixture into two liquid phases, and in the presence of a catalyst system containing (i) at least one catalyst selected from the group consisting of monovalent and divalent copper and (ii) a promoter selected from aromatic and aliphatic heterocyclic compounds which contain at least one carbon-nitrogen double bond in the heterocyclic ring, to produce CCl3CH2CHCl2.