Patented Aug. 26, 1947 2,426,172 UNITED STATES PATENT OFFICE 2,426,172 FLUORINATION OF UNSATURATED coMPounds Anthony F. Benning, Woodstown, N.J., assignor to Kinetic Chemicals, Inc., Wilmington, Del, a corporation of Delaware . No Drawing. Application May 12, 1942, Serial No. 442,662 3 Claims. (C. 260-653) 1. 2 A. This invention relates to the preparation solving the unsaturated compound in a suit of fluorine Compounds and has particular rela able solvent or by liquefying the olefine under tion to the fluorination of unsaturated aliphatic pressure. and unsaturated carbocyclic hydrocarbons. G. The following examples illustrate the in B. An object of this invention is to prepare vention. They do not limit it. Unless other certain fluorinated compounds by a process hav wise specified, the examples were run at One ing advantages over those which are known to atmosphere pressure and the parts are by weight. the prior art. A particular object of the inven tion is to prepare the compound C2Fs and CaF5C1. Eacample I Another object of the invention is to add at least O Forty-two parts of essentially dry C2F4. (B. P. two fluorine atoms to an unsaturated organic -76) were passed through 59 parts of SbF5 in compound by a simple method. Another object a brass reaction chamber during the course of of the invention is to prepare organic fluorine four hours. The reaction Was first carried Out compounds, which could previously be obtained at about atmospheric pressure then gradually only by the reaction of elemental fluorine, by a lowered to about 50 mm. Hg pressure, while the simpler and better process. Another object of 15 temperature varied Over the range 25 to 98° C. the invention is to prepare compounds which Approximately 9.2 parts of material were con cannot be obtained at all or can be obtained densed and 25 parts of a mixture of C2F4 and only with difficulty by prior art methods. Other C2Fs were collected Over Water. objects of the invention will be in part apparent The products were all transferred to one gas and in part hereinafter Set forth. 20. receiver and treated with an excess of bromine C. The objects of the invention are accom in order to convert the unreacted C2F4 to C2F4Br2. plished, generally Speaking, by reacting unsat The mixture was allowed to stand in Sunlight urated hydrocarbons, which may contain sub and the excess bromine then removed by sodium stituent groups, with antimony pentafluoride. Sulfite Solution. The reaction may be carried out in the vapor 25 The organic material was fractionated, most phase or in the liquid phase and the tempera of the material distilling at about -79. C. After ture at which the optimum reaction occurs dif further purification the vapor density of the gas fers with the particular compound being acted was found to be 1,673 g/l. at 26.6° C. and 230 upon. The temperature used should be chosen 30 mm. Hg pressure. This is equivalent to a molec to give the maximum yield of the desired prod ular weight of 136.2 as compared to a theoretical luct. The pressures used are also to be selected value of 138 for CFs. A boiling point of -78.2° according to the products which are in reaction. C. is reported in the literature for C2Fs. (Ruff, When a vapor phase reaction is used, the vapors Z. ftir anorg. und allg. Chemie, 210, 180 (1933).) of the organic material are preferably passed through liquid antimony pentafluoride, but may 35 Eacample II be simply passed over the surface of it. The hy About 41 parts of CF3Cl (B. P. -28) was drocarbon vapors may be preheated or precooled treated with 60 parts of SbF5 in a manner sim before admitting them to the reaction chamber, ilar to that used in Example I. The reaction was the treatment depending upon the question of 40 carried out at a temperature of about 95° C. and efficiency of reaction. at a pressure varying from 500-700 mm. Hg D. The reaction tube may be made out of any absolute. material which is substantially inert to the re The condensed reaction products were first actants and the products. A very Wide selection purged free of air and fractionated. Most of of materials is suitable, for example, copper, the material distilled at about -37 C. (uncorr.). brass, silver and platinum. 45 Bromine treatment was used to remove small E. After the reaction is completed, the re traces of unreacted C2F3Cl and the organic mate action products are separated by any method rial refractionated to obtain pure CF'sCl with a which accomplishes it. A satisfactory method boiling point of -37 C. Literature gives -38" of Separating products from reactants is to react 50 C. as the boiling point of C2F5Cl (Henne, Jour. the un-reacted starting materials with elemental Am. Chem. Soc. 56, 1726 (1934)). bromine and separate the products of reaction therefrom by distillation. Other methods of sep Eacample III aration may be adopted within the skill of the Acetylene dried by passage through concen art. 55 trated sulfuric acid was bubbled slowly through F. The temperatures of reaction are Capable SbF5 contained in a steel cylinder. The reac of greatest variation. For example, tempera tion was carried out at room temperature. The tures from -20 and -125 have been success effluent gases were then washed free of acid, fully used. If the process is carried out in liquid dried and fractionated. Material boiling at phase, the liquefaction may be obtained by dis- 60-64 C. at 360 mm. Hg pressure was obtained

------2,426,172 ... -- 3. --- 4. hich extrapolated to -52° C. at 760 mm. pres A rapid reaction took place with the sure, the boiling point of CHFCFa. A molec formation of some tar. The liquid product was ular weight of 88 was obtained for this material, Washed, dried and distilled. A product with a The theory for pure CHF=CF, 82. boiling range of 70-65 C, was obtained. Eacample IV Eacample XII About 5.5 parts of . C2C14 (B. P. 121) were Eight parts of dihydronaphthalene (B. P. slowly added to about 2.5 parts of SbF5 in a 212° C.) were added to three parts of SbF5. platinum-lined tube and the reaction allowed to The reaction mixture was extracted with ben proceed at room temperature for about 10-15 0. Zene, Washed with dilute HCl solution, washed minutes. The reaction products were Washed free of acid, dried and distilled. A boiling range free of acid, dried and distilled. A product of 50° to 220 C. was obtained for the product, with a distillation range of 85-120° C. Was ob slight decomposition occurring at about 200° C. tained, having a definite fraction at 92-93 C. H. This invention provides a new method of Addition of tWO atoms of F to C2Cl4 took place, fluorination and a new reaction. It has a The boiling point of CCF-CCl2F is 92.8° C. 5 tendency to introduce fluorine symmetrically Eacample V and to make possible the synthesis of compounds Whose Synthesis was heretofore considered diffic. Five parts of C2HCl3 were added to two parts cult. The reaction is easily controlled and per of SbF6 and allowed to react as in Example IV. mits the synthesis of highly fluorinated com The reaction mixture Was Washed with dilute 20 pounds which were previously obtainable only by hydrochloric acid, dried and distilled. A prod the use of elementary fluorine. In particular it uct with a boiling range of 71-90 was obtained, provides a new and more efficient method of having a definite cut at 72-73 C. The boil making the useful compounds C2F5C1 and C2Fs. ing point, of C2HCl3F2 is 72.5 C. Addition of 25 I. AS many apparently Widely different emi tWO atons of fluorine to C2HCl3 took place. bodiments of this invention may be made Without Eacample VI departing from the spirit and scope thereof, it is About nine parts of alpha-pinene, C10H16 to be understood that I do not limit myself to the (B. P. 154 C.), were added to five parts of SbF5 specific embodiments thereof except as defined in a platinum-lined tube. A violent reaction 30 in the appended claims. took place at room temperature. More pinene I claim: was added to lessen the Violence of the reaction. 1. The process of preparing C2Fs which com After wishing and drying the reaction mixture prises reacting C2F4 with SbF5 at a temperature WaS distilled. The product had a boiling range from about 25 to about 98° C. and at a pres of 90°-158 C. The fraction boiling at 90°-05 Sure between atmospheric and about 50 mm. C. upon analysis was found to contain fluorine. mercury, condensing the vapors from the reac tion, and separating the C2Fs. Eacample VII 2. The process of preparing C2F5C1 which About nine parts of styrene, C6H5C2H3 (B. P. comprises reacting CFC) substantially solely 146), were added to two parts of SbF5 in a 40 With SbF5 at a temperature of about 95° C. and platinum dish. The Washed and dried liquid a pressure of from 500 to 700 mm. of mercury reaction products upon distillation showed a absolute, and separating the C2F5C1. boiling range of 80-145° C. This material was 3. The process of preparing a halogenated found upon analysis to contain fluorine. ethane in which at least two halogen atoms are Eacample VIII 45 fluorine which comprises reacting a halogenated Six parts of 1,3-dichlorobutene-2, C4HgCl2 ethylene containing at least three halogen atoms (B. P. 128 C.) cooled to 0° C. Were added to two from the group consisting of fluorine and parts of SbF5 in a platinum-lined tube. The chlorine, with antimony pentafluoride at temper reaction was carried out at 0° C. The reaction 50 atures of from room temperature to 98° C., the mixture was treated with dilute hydrochloric halogenated ethylene and the antimony penta acid, Washed free of acid, dried and distilled. A fluoride being the sole reactants, and separating product with a boiling range of 75°-148° C. Was the halogenated ethane. obtained. Eacample IX 55 ANTHONY F. BENNING. Fourt parts of hexene-3 REFERENCES CTED (CH3CH2CH-CH-CH2CH3) (B. P. 70° C.) were added to three parts of The following references are of record in the SbF5 cooled to 0° C. The reaction product was file of this patent: Washed with HCl and water, washed free of acid, UNITED STATES PATENTS dried and distilled. A fraction boiling in the range 55 to 175° C. was obtained, as well as a Number Name Date tarry residue. 2,122,278 Clark ------June 28, 1938 Eacample X 65 2,146,725 Dunphy ------Feb. 14, 1939 1,677,831 Krause ------July 17, 1928 About four barts of cyclohexene (B. P. 83° C.) 1,754,656 StroSacker ------Apr. 15, 1930 Were added to two parts of SbF5 cooled to 0° C. in a platinum-lined reaction tube. The prod OTHER REFERENCES luct was treated as in Example IX and distilled, 70 Mellor, "Comprehensive Treatise on Inorganic A product with a boiling range of 35°-85° C. Was and Theoretical Chemistry," vol. 9, pp. 467-9. obtained. (Copy in Div. 59.) Eacample XI Ruff, "Berichte der Deutsche Chemische About eight parts of camphene (B. P. 159° C.) Gesellschaft, vol. 39, pages 4310-18 (1906). Were added in liquid phase to three parts of 5 (Copy in Patent Office Scientific Library.)