Dehydrofluorination process to manufacture hydrofluoroolefins
View Patent ↗Disclosed is a process for the manufacture of hydrofluoroolefins of the structure CF 3 CF═CHY, wherein Y can be H or F, comprising reacting at least one fluoropropane reactant of the structure CF 3 CFXCFYH, wherein X can be either F or H, and Y can be either F or H, provided that both X and Y′ are not both F, with a basic aqueous solution in the presence of a non-aqueous, non-alcoholic solvent, and in the presence of a phase transfer catalyst.
1. A process for the manufacture of hydrofluoroolefins of the structure CF 3 CF═CHY, wherein Y can be H or F, comprising reacting at least one fluoropropane reactant of the structure CF 3 CFXCFY′H, wherein X can be either F or H, and Y′ can be either F or H, provided that both X and Y′ are not both F, with a basic aqueous solution in the presence of a nonaqueous, nonalcoholic solvent, and in the presence of a phase transfer catalyst wherein the solvent is a ketone or an alkyl or aryl ether and wherein the yield of the reaction is at least 96%.
2. The process of claim 1 wherein the pH of the basic aqueous solution is greater than 8.
3. The process of claim 1 wherein the pH of the basic aqueous solution is between about 10 and about 13.
4. The process of claim 1 wherein the basic aqueous solution is made from a base selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium oxide, calcium oxide, sodium carbonate, potassium carbonate, sodium phosphate, potassium phosphate, and mixtures thereof.
5. The process of claim 1 wherein the phase transfer is catalyst is selected from the group consisting of crown ethers, onium salts, cryptands, polyalkylene glycols, and mixtures thereof.
6. The process of claim 1 wherein Y is F, X is F, and Y′ is H, or wherein Y is F, X is H, and Y′ is F, or wherein Y is H, X is H and Y′ is H.
7. The process of claim 5 wherein the phase transfer catalyst is either 18-crown-6, 15-crown-5, a quaternary ammonium salt or mixtures thereof.
8. The process of claim 7 wherein the base in the basic aqueous solution is potassium hydroxide and the phase transfer catalyst is either 18-crown-6, methyltrioctylammonium chloride or mixtures thereof.
9. The process of claim 1 wherein the dehydrofluorination is conducted at a temperature of from about 20° C. to about 150° C.
10. The process of claim 1 wherein the nonaqueous, nonalcoholic solvent is selected from the group consisting of 2-methyltetrahydrofuran, tetrahydrofuran, dioxane, diglyme, tetraglyme and mixtures thereof.
11. The process of claim 1 wherein the molar ratio of base in the basic aqueous solution to fluoropropane is from about 0.75:1 to about 10:1.
12. The process of claim 1 wherein the molar ratio of base to fluoropropane is from about 1:1 to about 4:1.
13. A composition comprising a hydrofluoroolefin of the structure CF 3 CF═CHY, wherein Y can be H or F, produced by the process comprising reacting at least one fluoropropane reactant of the structure CF 3 CFXCFY′H, wherein X can be either F or H, and Y′ can be either F or H, provided that both X and Y′ are not both F, with a basic aqueous solution in a nonaqueous, nonalcoholic solvent, and in the presence of a phase transfer catalyst ether and wherein the yield of the reaction is at least 96%.
14. The composition of claim 13 wherein the base in basic aqueous solution is selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium oxide, calcium oxide, sodium carbonate, potassium carbonate, sodium phosphate, potassium phosphate, and mixtures thereof.