Lewis acid catalyzed conjugated iodofluorination of fluoroolefins

• US 5,481,028 A
• Filed: 08/12/1994
• Issued: 01/02/1996
• Est. Priority Date: 07/29/1993
• Status: Expired due to Term

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Petrov, Viacheslav A., Krespan, Carl G.
• Primary Examiner(s): SIEGEL, ALAN M
• Application Number:
  US08/290,326
• Time in Patent Office: 508 Days
• Field of Search: 570/137, 570/161, 570/165, 570/174, 570/166, 570/168, 570/184, 568/684, 560/184, 562/833
• US Class Current: 560/184
• CPC Class Codes: C07C 17/04 to unsaturated halogenated hydrocarbons
• CPC Class Codes: C07C 19/16 and iodine
• CPC Class Codes: C07C 303/22 from sulfonic acids, by reactions not involving the formation of sulfo or halosulfonyl groups; from sulfonic halides by reactions not involving the formation of halosulfonyl groups
• CPC Class Codes: C07C 309/82 of a carbon skeleton substituted by singly-bound oxygen atoms
• CPC Class Codes: C07C 41/22 by introduction of halogens; by substitution of halogen atoms by other halogen atoms
• CPC Class Codes: C07C 43/123 both carbon chains are substituted by halogen atoms

Abstract

A process for the preparation of perfluoroalkyl iodides, especially perfluoroethyl iodide, by reaction of perfluorinated compounds which contain a carbon carbon double bond with ICl in HF solvent in the presence of Lewis acid catalysts. The compounds are used as telogens for the telomerization of tetrafluoroethylene to long-chain perfluoroalkyl iodides.

Claims

1. A process for the preparation of RCFICF₂ X wherein R is selected from the group consisting of F and C_n F_2n+1, n has a value of 1-10, X is selected from the group consisting of F and OR'"'"', and R'"'"' is a perfluoroalkyl containing up to about 10 carbon atoms, branched or straight, optionally containing in-chain ether oxygen, and having F, SO₂ F, or CO₂ CH₃ as an end group, provided that when X is OR'"'"', R is F, which process comprises reacting a compound of the formula RCF═

CFX where R, X and n are as defined above, with an ICl/HF mixture in the presence of a Lewis acid catalyst which increases the Ho acidity of HF of -11 to at least -13, at a temperature of from about 0°

to about 200°

C., wherein the Lewis acid catalyst is selected from the group consisting of BF₃, TaF₅ and NbF₅, and wherein the yield of RCFICF₂ X product is at least 50%.

2. A process according to claim 1 wherein R is C_n F_2n+1 and n is 1-5.

3. A process according to claim 2 wherein X is OR'"'"' and R'"'"' is a perfluoroalkyl wherein the alkyl moiety contains from 1-3 carbon atoms.

4. A process according to claim 1 wherein R is F.

5. A process according to claim 1 wherein the molar proportion of ICI to HF is from 0.01 to 1.

6. A process according to claim 1 wherein the ratio of ICI to TFE is 1:

1.

7. A process to claim 1 wherein the molar proportion of HF to TFE is 5 to 15.

8. A process according to claim 1 wherein the Lewis acid catalyst is selected from the group consisting of BF₃ and NbF₅.

9. A process according to claim 8 wherein the Lewis acid catalyst is BF₃.

10. A process according to claim 1 wherein the compound of the formula RCF═

CRX is RCF═

CF₂.

11. A process according to claim 1 wherein the RCF═

CFX is FSO₂ CF₂ CF₂ OCF(CF₃)CF₂ OCF═

CF₂.

12. A process according to claim 1 wherein the RCF═

CFX is CH₃ OC(═

O)CF₂ CF₂ OCF(CF₃)CF₂ OCF═

CF₂.

13. A process according to claim 9 wherein the compound of the formula RCF═

CFX is RCF═

CROR'"'"' wherein R'"'"' is a perfluoroalkyl wherein the alkyl moiety contains from 1-3 carbon atoms.

14. A process according to claims 1 where the ICI/HF mixture is formed by mixing I₂, Cl₂ and HF.

15. The process of claim 1 carried out at a temperature of about 20°

C. to about 100°

C.

16. A process for the preparation of C₂ F₅ I comprising reacting tetrafluoroethylene with ICl/HF mixture in the presence of BF₃.

17. A process for the preparation of ICF₂ CF₂ OCF₃ comprising reacting perfluoro-methyl vinyl ether with ICl/HF in the presence of BF₃.

18. A process for the preparation of ICF₂ CF₂ OCF₂ CF₂ CF₃ comprising reacting perfluoro-n-propylvinyl ether with ICl/HF mixture in the presence of BF₃.

19. A process for the preparation of RCFICF₂ X wherein R is selected from the group consisting of F and CnF_2n+1, n has a value of 1-10, X is selected from the group consisting of F and OR'"'"', and R'"'"' is a perfluoroalkyl containing up to about 10 carbon atoms, branched or straight, optionally containing -n-chain ether oxygen, and having F, SO₂ F, or CO₂ CH₃ as an end group, provided that when X is OR'"'"', R is F, which process comprises reacting a compound of the formula RCF═

CFX where R, X and n are as defined above, with an ICl/HF mixture in the presence of a BF₃ Lewis acid catalyst which increases the --Ho acidity of HF of 11 to at least 13 and and wherein the yield of RCFICF₂ X product is at least 60%.