ADDITION OF HYDROFLUOROCARBONS TO FLUOROOLEFINS

Abstract: A process is disclosed for forming adducts of the formula: RR<1>R<2>CCR<1>R<2>F or (FR<1>R<2>CCRR<2>CH2)2 where R is CH3, CH2F, C2H4F or F(CF2)nCH2CH2 (where n is an integer from 1 to 10) each R<1> is H, Cl, F or CF3 and each R<2> is H, F or CF3. The process involves reacting a saturated compound of the formula RF with an olefin of the formula R<1>R<2>C=CR<1>R<2> in the liquid phase in the presence of antimony pentafluoride catalyst (provided that when (FR<1>R<2>CCR<1>R<2>CH2)2 is formed, the saturated compound is CH3CHF2 or CH2FCH2F and anhydrous HF is present).

Description: 8/42645 TITLE PCT/US98/05541 ADDITION OF HYDROFLUOROCARBONS TO FLLOROOLEFINS FIELD OF THF INVENTION This invention concerns a process for the antimony pentafluoride catalyzed addition of hydrofluorocarbons across the carbon-carbon double bond of fluoroolefins. BACKGROUND Processes for the addition of 1, 1 , 1-trifluoroethane to fluorinated olefins using antimony pentafluoride as a catalyst have been described (see G. G. Belen' ii and L. S. German,Soviet Scientific Reviews, Sect. B, pp. 195-6 , M. E. Volpin ed. , (Harwood Academic Publishers, 1984). Processes for the addition of trifluoromethanes, including CHF 3 , to certain fluorinated olefins using aluminum chlorofluoride as a catalyst have also been described (see U.S. Patent Application No. 06/000,720 and International Application No. PCT/US96/10872). Hydrofluorocarbons can be prepared by both processes. Hydrofluorocarbon products are useful as refrigerants, fire extinguisnaflts, heat transfer media, propellants, foaming agents, gaseous dielectrics, sterilant carriers, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, displacement drying agents and power cycle working fluids. There is an interest in developing more efficient processes for the manufacture of hydrofluoroalkanes. SUMMARY OF TH-R INVENTION A process is provided for forming an adduct of the formula RR l R 2 CCR 1 R 2 F or (FR 1 R 2 CCRR2CH 2 ) 2 wherein R is selected from the group consisting of CH 3 , CH 2 F, C 2 H 4 F and F(CF 2 ) n CH 2 CH 2 where n is an integer from 1 to 10, each R 1 is independently selected from the group consisting of H, Cl, F and CF 3 and each R 2 is independently selected from the group consisting of H, F and CF3. The process comprises reacting a saturated compound of the formula RF with an olefin of the formula R i R 2 C=CR l R 2 in the liquid phase in the presence of antimony pentafluoride catalyst; provided that when (FR 1 R 2 CCR 1 R 2 CH 2 ) 2 is formed, the saturated compound is CH 3 CHF 2 or CH 2 FCH2F and anhydrous HF is present. DETAILED DESCRIPTION OF THE INVENTION This invention provides a liquid phase process for the addition of (a) saturated compounds of the formula RF, where R is selected from the group consisting of CH 3 , CH 2 F, C 2 H 4 F and F(CF 2 ) n CH 2 CH 2 , where n is an integer from 1 to 10 , to (b) olefins of the formula R l R 2 C =CR l R 2 where each R 1 is independently selected from the group consisting of H, Cl, F and CF 3 and each R 2 is independently selected from the group consisting of H, F and CF 3 ; to form adducts of the formula RR ^CCR' R-F or ( FR l R CCR ' R-CH : ) : in the presence of antimony pentafluoride catalyst (provided that when ( FR' R 2 CCR 1 R 2 CH : ) 2 is formed, the saturated compound is CH 3 CHF 2 or CH FCH 2 F and anhydrous HF is present). Examples of olefins of the formula R 1 R 2 C =CR 1 R 2 which can be used in the process of this invention include CF 2 =CF 2 , CF 3 CF=CF 2 , CC1F=CF 2 . CC1F=CC1F, CHF=CF 2 , CH 2 =CF 2 , CF 3 CH=CF 2 , CHF=CFCF 3 and CH 2 =C(CF 3 )CF 3 . Some of the olefins are commercially available, the others can be prepared by known methods. Examples of saturated compounds of the formula RF which can be used in the process of this invention include CH 3 F, CH 2 F 2 and CH 3 CHF 2 . Solvents or diluents may be employed in the process of the present invention. The solvent or diluent is selected so that it will not be reactive in the process or lead to the deactivation of the antimony fluoride catalyst. Suitable solvents or diluents may be selected from the group consisting of perfluoroalkanes ©r perftaoethers (e.g., perfluorocyclobutane); the cyclic dimer of hexafluoropropene (i.e., the isomeric perfluorodimethylcyclobutanes); perfluoroethers or perfluoro tertiary amines. Preferred on the basis of its ready availability to those skilled in the art is the cyclic dimer of hexafluoropropene. In one embodiment a one to one adduct of the saturated compound and the olefin is formed. It is noted in this regard that the saturated compounds of the formula F(CF2) n CH 2 CH 2 F can themselves be produced as one to one adducts. For example, the addition reaction of CH 2 FCH 2 F to CF 2 =CF 2 can be used to produce F(CF 2 ) 2 CH 2 CH 2 F. In a second embodiment of this invention the addition of the hydrofluorocarbons CH 3 CHF 2 and/or FCH 2 CH 2 F to olefins of the formula R 1 R 2 C=CR 1 R 2 in the presence of antimony pentafluoride can be done in the presence of anhydrous HF. The molar ratio of HF:SbF5 is in the range of 10:1 to 40: 1, preferably 20: 1. The addition product or adduct is (FR 1 R 2 CCR 1 R 2 CH 2 ) 2 . Without wishing to be bound by theory, it is believed that when CH 3 CHF 2 is used it isomerizes to FCH 2 CH 2 F before reaction with the olefin. When the addition product (adduct) contains chlorine, the chlorine can be removed by either reaction with HF in the presence of a fluorination catalyst (e.g., Cr 2 O 3 ) or by reaction with hydrogen in die presence of a hydrogenation catalyst (e.g. , palladium supported on carbon). The adduct is thereby converted from a hydrochlorofluorocarbon to a hydrofluorocarbon. The temperature employed tn the process of the present invention t ypically ranges from about - 10°C to about 100 5 C. The preferred temperature range is from about 0°C to 80°C. Reaction time is not critical and typically ranges from about 5 seconds to about 24 hours. From about 1 to 16 hours, are usually sufficient. The pressure employed in the reaction is not critical. The reaction is normally run at pressures in the range of from 0 to 300 psig (101 kPa to 2169 kPa). Autogenous pressures are usually employed; however the pressure should not be allowed to rise above 300 psig when using tetrafluoroethylene because of safety considerations. Where the reaction conditions are heterogeneous, some degree of agitation is often desirable. Since the catalysts are water sensitive, reagents and equipment should be dried before use. The proportion of catalyst to the olefin reactant is typically from about 0.01:1 to about 0.5:1; a range of from 0.1:1 to about 0.5:1 is preferred. The proportion of saturated compound to olefin is preferably at least about preferably 1: 1, when forming RR 1 R 2 CCR 1 R 2 F and preferably at least about 2:1 when forming (FR 1 R 2 CCR 1 R 2 CH 2 )2- Of note are embodiments which use saturated compounds as a solvent such that they are present in substantial excess. The reaction can be done in batch, semi-batch, semi-continuous or continuous modes in one or more reaction vessels. On a laboratory scale, the reaction can be done in shaker tubes, where all reagents are combined before the reaction vessel is sealed and the reaction begun. It can also be done in autoclaves equipped with an agitator. Product(s) may be isolated by standard chemical engineering techniques, e.g., fractional distillation. Without further elaboration, it is believed that one skilled in the art can, using the description herein, utilize the present invention to its fullest extent. The following specific embodiments are, therefore, to be construed as merely illustrative, and do not constrain the remainder of the disclosure in any way whatsoever. EXAMPLES EXAMPLE 1 CH ? F 7 + CF 9 =CFτ → CH 7 FCF?CF Difluoromethane (39.0 g, 0.75 mol), antimony pentafluoride (45 g, 0.2 mol ) and tetrafluoroethylene (30.0 g, 0.3 mol) were added to a 250 mL steel autoclave. The reaction mixture was stirred at 50°C for 8 hours, additional tetrafluoroethylene (30.0 g, 0.3 mol) added, and stirring was maintained at 50°C for 8 more hours. The gaseous reaction products were condensed in a trap, then distilled to yield CH 2 FCF 2 CF 3 (75 g, 80% yield), b.p. 0- l °C. l'F NMR (δ, pp , relative to CF 3 CO 2 H) of CH 2 F CF 2 B CF 3 : A 8 5> B 51.5, C 167.6, J F A C is 9 Hz, J p B. H \ s 12 Hz, J F C . H is 45 Hz. l H NMR (δ, ppm, relative to TMS): 5.26 (CH 2 ). COMPARATIVE EXAMPLE A CH 7 F? + CF 7 =CF 7 → No Reaction ) Difluoromethane (26 g), aluminum chlorofluoride (AlCl x F y where χ +y=3, 5 g) and tetrafluoroethylene (30 g) were added to a 400 mL Hastelloy™ -nickel alloy shaker tube. The aluminum chlorofluoride was prepared by the reaction of A1C1 3 and CC1 3 F according to the method described in U.S. Pat. No. 5,162,594, column 4, lines 35-57. The reaction mixture was agitated at 25°C for 12 hours. No reaction was detected. CH,F, + CF, CFCF, → CH,FCF(CF,) ? Difluoromethane (39.0 g, 0.75 mol), antimony pentafluoride (45 g, 0.2 mol) and perfluoropropylene (66 g, 0.44 mol) were added to a 250 mL steel autoclave. The reaction mixture was stirred at 80°C for 20 hours. The reaction products were condensed in a trap, then distilled to yield CH 2 FCF(CF 3 )2 (80 g, 90% yield), b.p. 22-24°C. 19F NMR (δ) of CH 2 F C CFB(CF 3 A) 2 : F A 0.5, F B 114, F C 167.5, j F A F B i s 7 Hz, J F A . F C is 9.5 Hz, J p C . F B i s 12.5 Hz, J F A . H is 11 Hz. *H NMR (δ): 5.25 (CH 2 ), J F C - is 45 Hz, JpB-H is 16 Hz. Mass spectrum (m/z, assignment, %): 201 (M-H) + 0.03, 183 (M-F)+ 2.04, 163 (C 4 HF 6 )+ 1.4, 150 (C 3 F 6 )+ 34.4, 133 (C 3 H 2 F 5 ) + 3.4, 131 (C 3 F 5 )+ 6.3, 119 (C 2 F 5 )+ 4.4, 114 (C 3 H 2 F 4 )+ 229, 113 (C 3 HF 4 )+ 27.3, 100 (C 2 F 4 )+ 22.6, 69 (CF 3 )+ 100. EXAMPLE 3 CH 3 F + CF ? =CF -> CH,CF ? CF 3 Fluoromethane (35.0 g), antimony pentafluoride (15 g) and tetrafluoroethylene (50 g) were added to a 400 mL Hastelloy™ nickel alloy shaker tube. The reaction mixmre was agitated at 25 °C for 6 hours followed by agitation at 50°C for 10 hours. The reaction products were condensed in a dry- ice trap, then distilled to yield 99% pure CH 3 CF 2 CF 3 (HFC-245cb, 45 g), b.p. -13 to -12°C. The yield of HFC-245cb was 67%. COMPARATIVE EXAMPLE B CHF^ + CF, =CF, → PTFE Trifluoromethane (21 g), antimony pentafluoride (7 g) and tetrafluoroethylene (30 g) were added to a 400 mL Hastelloy™ nickel alloy shaker be. The reaction mixture was agitated at 25 °C for 12 hours. The only product isolated was polytetrafluoroethylene (PTFE, 15 g). EXAMPLE 4 CH 3 F + CF 2 =CFCF 3 → (CF 3 ) 2 CHF + (CF 3 ) 2 CFCH 3 + (CF,),CFC(CH,h + (CF,) 7 CFC 7 H Fluoromethane (20 g), antimony pentafluoride (15 g) and hexafluoro- propylene (75 g) were added to a 400 mL Hastelloy™ nickel alloy shaker mbe. The reaction mixture was agitated at 50°C for 14 hours. The reaction products were condensed in a dry-ice trap, then distilled to yield a mixmre (68 g) containing, based on *H and 1*F NMR, 66 % (CF 3 ) 2 CHF, 11 % (CF 3 )2CFCH 3 , 5% (CF3) 2 CFC 2 H 5 , 9% (CF 3 ) 2 CFC(CH 3 ) 3 . The yield of (CF 3 )2CFCH3 was EXA P E 5 CH?F + CC1F=CF? - C1CF CF ? CH 3 + CF„CF ? CH 3 + CF 3 CC1FCH 3 Fluoromethane (17 g), antimony pentafluoride (15 g) and chlorotrifluoroethylene (59 g) were added to a 400 mL Hastelloy™ nickel alloy shaker tube. The reaction mixture was agitated at 50°C for 12 hours. The reaction products were condensed in a dry-ice trap, then distilled to yield a mixture (12 g) containing, based on l K and 19 F NMR, 87.5% C1CF 2 CF 2 CH 3 , 6.5% CF 3 CF 2 CH 3 , 4% CF 3 CFC1CH 3 and 1 % unidentified product. The yield of chlorofluoropropanes was 17.4%. EXAMPLE 6 CH 3 F + CHF=CF, → CH 3 CHFCF 3 + CH?FCF 3 Fluoromethane (10 g), antimony pentafluoride (10 g) and trifluoroethylene (24 g) were added to a 400 mL Hastelloy™ nickel alloy shaker mbe. The reaction mixmre was agitated at 25 °C for 14 hours. The reaction products were condensed in a dry-ice trap, then distilled to yield a mixmre (12 g, b.p. 0 to 2°C) containing, based on { H and 19 F NMR, 90% CH 3 CHFCF 3 and 10% CH 2 FCF 3 . The yield of CH 3 CHFCF 3 was 38.6%. EXAMPLE 7 CH 2 F 2 + CC1F=CC1F → CH 7 C1CF 7 CF 7 C1 Difluoromethane (18 L, 0.7 mol), antimony pentafluoride (22 g, 0.1 mol) and 1 ,2-dichlorodifIuoroethylene (26.6 g, 0.2 mol) were added to a 250 mL steel autoclave. The reaction mixture was stirred at room temperamre for 8 hours followed by heating the autoclave in a boiling water bath. The reaction products were condensed in a trap cooled to -78°C. Excess difluoromethane was separated by distillation. The residue was washed with water, dried and distilled to give in 32% yield CH 2 CICF 2 CF 2 C1 (12 g, b.p. 62°C to 64°C). 19F NMR (δ) of CH 2 C1CF 2 B CF 2 A C1: -50 s (2F A ): 41.5 t (2F B ). Η NMR (δ): 3.8; J [H - F B ] is 14 Hz. Mass spectrum (m/z, assignment, %): 184 (M+, C 3 H 2 C1 2 F 4 + . 0.5); 165 (M-F, C 3 H 2 C1 2 F 3 + , 0.3); 149 (M-Cl, C 3 H 2 CIF 4 + , 17.7): 99 (C 2 H 2 C1F 2 + , 100); 85 (CC1F 2 +, 33); 64 (C 2 H 2 F 2 + , 12). EXAMPLE 8 CH CHF ? + CF ? =CF ? → CH^CHFCF ? CF 3 + CH 9 FCH?CF 7 CF 3 1,1-Difluoroethane (53 g, 0.8 mol), antimony pentafluoride (44 g, 0.2 mol) and tetrafluoroethylene (8.5 L, 0.3 mol) were added to a 250 mL steel autoclave. The reaction mixture was stirred at 40°C to 50°C for 10 hours. The reaction products were bubbled through a gas-washing bottle containing water and condensed in a trap cooled to -78°C. Excess 1,1-difluoroethane was separated by distillation. The residue was washed with water, dried and distilled to yield a mixture in 40% yield (20 g, b.p. 23°C to 27°C) containing CH 3 CHFCF 2 CF 3 (89%) and CH 2 FCH 2 CF 2 CF 3 (11 %). l*F NMR (δ) of CH 3 lCH2FDCF A F B CF 3 : 7.5 (3F A ); 55 (F A , F B , AB-system); 120 (FD); J p C_ F D is 10 H z; is 16 Hz; -H 2 ] is 17 Hz; J [F D. H 2 ] is 45 Hz. *H NMR (δ): 1. 7 Hz. 19 F NMR (δ) of CH 2 1 F C CH 2 2 CF 2 B CF 3 A : 11.5 (3F A ); 42.5 (2F B ); 147.5 (FC); 55 (F B ); J(F B -FC) is 5 Hz; J(F B _ H *) is 18 Hz; J(F C . H 2 ) is 45 Hz; J(FC. H l) is 28 Hz. EXAMPLE 9 CH.CHF, + CF ? =CF, → (CF,CF,),(CH ? ), + CF,CF=CHCH ? CF,CF 3 Anhydrous HF (80 mL), 1,1-difluoroethane (11 g, 0.2 mol), antimony pentafluoride (45 g, 0.2 mol) and tetrafluoroethylene (40 g, 0.4 mol) were added to a 250 mL steel autoclave. The reaction mixmre was agitated at room temperamre for 8 hours followed by heating the autoclave in a boiling water bath. The reaction products were collected in a gas-washing bottle containing water. The organic layer was separated, washed with water, dried and distilled to yield a mixmre in 50% yield (27 g, b.p. 46 to 58°C) containing CF 3 CF 2 CH 2 CH 2 CF 2 CF 3 (70%) and CF 3 CF=CHCH 2 CF 2 CF 3 (30%). The reaction mixmre also contained a small amount of l -perfluoroethyl-2.2.3.3- tetrafluorocyclobutane »9F NMR (δ) of CF 3 CF 2 CH : CH 2 CF 2 CF 3 : 1 1 (CF 3 ); 44.5 (CF 2 ): J H . F was 16 Hz. l H NMR (δ): 2.5 (2CH 2 ). Mass spectrum (m/z. assignment, %): 247 (M-F, C 6 H F 9 + . 0. 1): 227 (C 6 H 3 F 8 + , 9.7); 197 (C 5 H 4 F 7 + , 18.9); 177 (C 5 H 3 F 6 + , 29.6); 157 (C 5 H 2 F 5 + , 6.7); 127 (C 4 H 3 F 4 + , 24.3); 119 (C 2 F 5 + , 5.6); 113 (C 3 HF 4 +, 31.3); 100 (C 2 F 4 + , 3.9); 77 (C 3 H 3 F 2 +, 43.3); 69 (CF 3 + , 68.4). l*F NMR (δ) of CF 3 CF B =CH CH 2 1 CF 2 C CF 3 D : -1.2 (3F a ); 10.5 (3FD); 42.5 (2F C ); 55 (F B ); J(F -F B ) is 10 Hz. l H NMR (δ): 3.1 (2H 1 ); 5.8 (1H 2 ); J(H 2 -F B ) is 30 Hz; J(H l -H 2 ) is 7.5 Hz; J(U l -F ) is 10 Hz. Raman spectrum (v, cm *1 ): 1728. Masδ spectrum (m/z, assignment, %): 246 (M + , C5H3F9+, 9.6); 227 ( H3F8+, 8.5); 207 (C 6 H 2 F 7 +, 2.3); 177 (C 5 H 3 F 6 +, 7); 157 (C 5 H 2 F 5 +, 0.7); 127 (C 4 H 3 F 4 +, 66); 119 (C 2 F 5 +, 2.6); 113 (C 3 HF 4 +, 20.3); 77 (C 3 H 3 F 2 +, 100); 6 (CF 3 +, 68.4). Mass spectrum (m/z, assignment, %): 227 (MF + , C 6 H 3 F 8 +, 0.8); 207 (C 6 H 2 F 7 +, 1.6); 177 (C 5 H 3 F 6 +, 1.8); 157 (C 5 H 2 F 5 +, 1.9); 127 (C 4 H 3 F 4 +, 4.5); 113 (C 3 HF 4 +, 9.7); 100 (C 2 F 4 +, 13); 77 (C 3 H 3 F 2 +, 12); 69 (CF 3 +, 10.6); 64 (C 2 H 2 F2 + , 100). COMPARATIVE EXAMPLE C (CH 3 ) ? CHF + CF 9 =CF ? - Tar Isopropyl fluoride (25 g), antimony pentafluoride (25 g) and tetrafluoroethylene (40 g) were added to a 400 mL Hastelloy™ nickel alloy shaker mbe. The reaction mixture was agitated at 25 °C for 12 hours. Only a tarry product was isolated. COMPARATIVE EXAMPLE D CF 3 CH ? F + CF?=CF? - PTFE 1,1, 1,2-Tetrafluoroethane (50 g), antimony pentafluoride (5 g) and te t rafluoroethylene (40 g) were added to a 400 mL Hastelloy™ nickel alloy shaker mbe. The reaction mixmre was agitated at 50 °C for 12 hours. The product isolated was polytetrafluoroethylene (PTFE, 10 g) along with recovered CF 3 CH 2 F (46 g). COMPARATIVE EXAMPLE E HCF ? CF ? CH 7 F -I- CF 7 =CF 7 → PTFE 1 , 1 ,2 , 2,3-Pentafluoropropane (55 g), antimony pentafluoride (20 g) and tetrafluoroethylene (30 g) were added to a 400 mL Hastelloy™ nickel alloy shaker mbe. The reaction mixmre was agitated at 50°C for 12 hours. The product isolated was poly tetrafluoroethylene (PTFE, 20 g) along with recovered HCF 2 CF 2 CH 2 F (32 g). COMPARATIVE EXAMPLE F CH ? F ? + CF 2 =CF 7 → CH,FCF ? CF 3 + CF 7 -=CF 2 -» PTFE Difluoromethane (55 g), antimony pentafluoride (20 g) and tetrafluoroethylene (TFE, 50 g) were added to a 400 mL Hastelloy™ nickel alloy shaker mbe. The reaction mixmre was agitated at 50°C for 12 hours. At this time addtional TFE (50 g) was added to the reaction mixmre and agitation was continued for 12 hours at 50°C. The product isolated was polytetrafluoroethylene (PTFE, 20 g) along with recovered CF 3 CF 2 CH 2 F (32 g).

Claims: CLAIMS 1. A process for forming an adduct of the formula RR l R 2 CCR l R 2 F or (FR l R 2 CCRR 2 CH 2 )2 wherein R is selected from the group consisting of CH 3 , CH 2 F, C 2 H F and F(CF 2 ) n CH 2 CH2 here n is an integer from I to 10, each R 1 is independently selected from d e group consisting of H, Cl, F and CF 3 and each R 2 is independently selected from me group consisting of H, F and CF 3 , comprising: reacting a saturated compound of the formula RF with an olefin of the formula R 1 R 2 C=CR 1 R 2 in the liquid phase in die presence of antimony pentafluoride catalyst; provided that when (FR 1 R 2 CCR 1 R 2 CH 2 )2 is formed, the saturated compound is CH 3 CHF 2 or FCH 2 CH 2 F and anhydrous HF is present.

Inventors: BELEN KII GENNADII G, PETROV VIACHESLAV A, RESNICK PAUL R, BELEN'KII, GENNADII G., PETROV, VIACHESLAV A., RESNICK, PAUL, R.
Applicants: BELEN KII GENNADII G, DU PONT, PETROV VIACHESLAV A, RESNICK PAUL R, BELEN'KII, GENNADII G., E.I. DU PONT DE NEMOURS AND COMPANY, PETROV, VIACHESLAV A., RESNICK, PAUL, R.
Application year: 1998
Main classification: C07C17
IPC codes: C07B61, C07C17, C07C19