METHOD FOR PRODUCTION OF POLYFLUOROALKANES Russian patent published in 1996 - IPC

FIELD: production of surfactants, monomers and solvents. SUBSTANCE: method is carried out by oxidizing decarboxylation of salts of RCOOH acids or mixture of RCOOH and R′COOH to produce polyfluoroalkanes having common formula R-R or R-R′ respectively. Said reaction takes place at 90-110 C in aqueous solution of persulfates of alkali metals, initial concentration of origin salts being 28-55 mass %. Sodium salt of perfluorobutyric acid R = C₃F₇ having essential formula C₄F₇NaO₂ is used as reagent 1. Sodium salt off hydroperfluoranante acid R = C₆HF₁₃ having essential formula C₇HF₁₃NaO₂ . Desired products are: perfluoro hexane having essential formula C₆F₁₄ and boiling point 57.2 C, hydroperfluoro nonane having essential formula C₉HF₁₉ and boiling point 139 C, dihydroperfluoro dodecane having essential formula C₁₂H₂F₂₄, and boiling point is 202-204 C, and melting point is 68-69 C. Sodium salt of perfluorovaleric acid R = C₄F₉ having essential formula C₄F₉NaO₂ and sodium salt of 5-hydroperfluoro valeric acid R = C₄HF₈ having essential formula C₄HF₈NaO₂ are used as reagents 2. Desired products are perfluoro octane having essential formula C₈F₁₈ and boiling point 104 C, hydroperfluoro octane having essential formula C₈HF₁₇ and boiling point 114-115 C, dihydroperfluoro octane having essential formula C₈H₂F₁₆ and boiling point 134-135 C. Sodium salt of perfluorobutyric acid R = C₃F₇ having essential formula C₄F₇NaO₂, sodium salt of 7-chloroperfluoroenanthic acid R = C₆ClF₁₃ having essential formula C₇ClF₁₃NaO₂ are used as reagents 3. Desired products are: 1-chloroperfluoro nonane having essential formula C₉ClF₁₉ and boiling point 151.5 C, dichloroperfluoro dodecane having essential formula C₁₉Cl₂F₂₄ and boiling point 221-222 C and melting point 90-91 C. Sodium salt of 9-hydroperfluoropelargonic acid R = C₈HF₁₆ having essential formula C₉H₁₆NaO₂ is used as reagent 4. Desired product is 1,16-dihydroperfluoro hexadecane having essential formula C₁₆H₂F₃₂ and boiling point 262 C and melting point 120-123 C. Sodium salt of 5,6-dichloroperfluorocaprylic acid R = C₇Cl₂F₁₃ having essential formula C₈Cl₂F₁₃NaO₂ is used as reagent 5. Desired product is 2,3,12,13-tetrachlorperfluoro tetradecane having essential formula C₁₄Cl₄F₂₆ and boiling point 290 C. Sodium salt of 13-hydroperfluorotridecanoic acid R = C₁₃HF₂₆ having essential formula C₁₄HF₂₆NaO₂ is used as reagent 6. Desired product is 1,24-dihydroperfluoro tetracosane having essential formula C₂₆H₂F₅₂ and melting point 222 C. EFFECT: improves efficiency of method. 1 tbl