[1]3 @ 3 2 6 , 9 7 6 United States Pateiit Office Patented June 20, 1967 3,326,976 FLUORINATED GE4M-DIAMINES AND FLUORINATED GEM-ALKYLDIAMINES AND THE PROCESS FOR TBIEIR PREPARATION 5 William J. Mddleton, Wilmington, Del., assignor to E. 1. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware No Drawing. Filed Dec. 11, 1963, Ser. No. 329,904 13 Claims. (Cl. 260-583) 10@ This application is a continuation-in-part of my coassigned application, Serial No. 134,815, filed August 30, 1961, now abandoned. This invention relates to new fluorinated nitrogen-containing compounds and to their preparation. 15 The formula, CF2(NH2)2, is disclosed in the literature [C.A. 51, 6077C (1957)]. However, ct-fluoro primary amines, the class of which the above represented compound is a member, are known to be unstable :and lose hydrogen fluoride readily. For example, a-aminoper20 fluoropropane, prepared by reacting hydrogen fluoride with hexafluoroisopropylideneimine, c ! F3ccF3 @H 25 is unstable and easily loses hydrogen fluoride. At page 243 of Simons, "Fluorine Chemistry," volume 2, the author states that amines which contain fluorine atoms vicinal to the primary amino group have not been reported but that such compounds would be expected to yield nitriles by 30 loss of hydro.-en fluoride according to the equation: XCF,CF,NHT->XCF,CN+2HF Further, compounds having two amino groups attached to the same carbon atom are known to be unstable (Whit35 more, "Organic Chemistry," second edition, page 329). Illustrative is diaminomethane, CH2(NH2)2, which has never been reported as existing in the free state. Only its hydrohalide salts, which can be prepared from formamide, are known to be stable. (See Whitmore, cited 40 above, and Ber. 47, 2698) - The present invention represents a great advance in the art by providin .- compounds which have two amino groups attached to the same carbon atom but nevertheless are found, quite unexpectedly, tobe stable, as evidenced 45 by their use as polymer intermediates. This stability is completely unpredictable from the heretbfore known properties of such compounds, i.e., gem-diamines. In contrast to the above-discussed a-fluoroamines, the amines of this invention contain no fluorine atoms on the carbon to 50 which the amino groups are attached and therefore do not decompose by loss of hydrogen fluoride. The compounds of this invention are of the general formula: R 55 I CF2 Y I / XHN-0-N I \ CF2 Z 60 wherein R and RI, which can be the same or different, are hydrogen, halogen, perhaloalkyl of up to 18 catbons, or whydroperhaloalkyl of up to 18 carbons, the halogens in each instance being of atomic number 9, to 17, i.e. 65 chlorine or fluorine; X is hydrogen, alkyl of up to 18 carbons, cycloalkyl of up to 7 carbons, or aryl of up to 14 carbons; Y taken singly is hydrogen, alkyl of up to 18 carbons, cycloalkyl of up to 7 carbons, aryl of up to 14 carbons, or amino, including mono- and disubstituted 70 alkylamino of up to 18 carbons and monosubstituted arylamino of up to 14 carbons; and Z taken singly is 2 hydrogen, alkyl of up to 18 carbons, or cycloalkyl of up to 7 carbons' The products o' this inventioii are prepared by the general process which comprises reacting an alkylidenimine of the formula: NX R-CF2-0 11 CF2-R' in which X, R and R' -have the above indicated meanings, with at least an equivalent molar amount of ammonia a primary or secondary alkyl amine of up to 18 carbons: a primary arylamine of up to 14 carbons, a primary or secondary cycloalkylamine of up to 7 carbons, hydrazine, a mono- or sym. or unsym. disubstituted hydrazine in which the substituent is of the group consisting of alkyl of up to 18 carbons, aryl of up to 14 carbons, orcycloalkyl of up to 7 carbons. After addition of the ammonia, amine, etc., is completed, the reaction mixture is maintained under reflux for at least 15 minutes. Thereafter, the reaction mixture is removed from the reactor and the desired products are isolated by conventional means e.g., the solvent is removed by evaporation, and the residue is then distilled to isolate the desired product. Preferably, the ammonia, amine, etc., and imine are present in equimolar amounts. The reaction can be carried out in the presence or absence of a medium which can be any mutual solvent which is normally liquid and which will not react with the reactants or reaction products. Examples of suitable solvents are chloroform, methylene chloride, dimethyl and diethyl ethers, tetrahydrofuran, cyclohexane, etc. Since the reaction is effected under reflux conditions, the temperatur6 of reaction will depend upon the particular solvent and reactants employed. The operating pressure is not critical, and therefore, it is most convenient to operate at am@bient pressure. Thereafter, the desirect products are isolated by conventional means, e.g., by fractional distillation, etc. The above process is illustrated generically by the equation: NX y H-N-X 11 / , I ROF2-c-CF2R' + HN RCFa-cCF2R, \Z z y in which R, W, Y, Z, and X have the already indicated meanings. Alkylideneimines of the general formula: R-CF2-C-C F2-R' HN in which the R's have the already indicated meanings are made by reacting a polyhalothioketone, in which each of the carb6ns adjacent to, the thiocarbonyl group contain at least two fluorine atoms, with hydrazoic acid. Although not essential, in the method which produces the alkylideneimines from the polyhalothioketone and hydrazoic acid, as,a safetymeasure, it is desirable to conduct the reaction in two steps. In the first step the addition of the hydrazoic acid to the polyhalothioketone is carried out at -50' C. to O' C.; and, after the addition is complete, the mixture is heated to between 20' and 100' C. until reaction is complete, as evidenced by cessation of gas evolution. This makes it possible to keep the reaction under control when using elementary reaction equipment not suitable for rigorous process conditions. Preferably, the acid and thioketone are contacted at a temperature between -20' C. and O' C., and the reaction mixture is thereafter warmed to a temperature between 40' C. iand 60' C.
[2]3,326,976 3 The pressure at which the reaction is conducted is not critical; and therefore, it is most convenient to operate at ambient pressure. The hydrazoic acid and polyhalothioketone react in equimolar amounts, and therefore, these reactants are 5 preferably used in a 1: 1 molar ratio. However, an excess of either reactant can be employed at the expense of process efficiency. Although it is not essential, it is preferred that the hydrazoic acid and polyhalothioketone be contacted in a 10 mutually iner-t organic solvent. Any mutual solvent which is normally liquid and which will not react with the reactants and products is satisfactory. Examples of suitable solvent,s -are chloroform, methylene chloride, diw-ethyl and diethyl ethers, tetrahydrofuran, cyclohexane, etc. The 15 amount of solvent, if any, is not critical and it can equal or exceed the weight of reactants by many fold. The polyhalothioketones useful in preparing the imine intermediates employed in the preparation of the compounds of this invention ;are those which correspond in 20 structure to R-CF2-C-CF2--R' 11 s 4 (B) Oll N@t I dehydrating agent 11 R-CF2--c CF2-R' R-CF2-C-Cr@2-R' I - In step A the polyhaloketone is contacted with at least one molar equivalent of ammonia (X@H) or an amine (X=alkyl or cycloalkyl) at a temperature in the range o' - 50' C. to 10' C. A normally liquid reaction medium is 1- preferably used to assist in the dissipation of the heat of reaction. For optimum control of the reaction, it is preferred that all of the ammonia or amine be added incrementally to a cold (- 15' C. or less) solution of the polyhaloketone while the temperature of the reaction mixture is maintained at (@ or less. The amin I ohydroxy polyhaloalkane produced can'be isolated, if desired, by known techniques. In Step B the intermediate from Step A is dehydrated by warming a mixture of the intermediaie, a dehydrating agent (POC13), and an acid acceptor (pyridine) to at least the reflux temperature of the mixttire. The intermediate from Step A can be employed in this step either in its pare or crude form, i.e., the dehydrating agent and acid acceptor can be added directly to the product mixture ftom Step wherein R and R' have the previously indicated meanings. 25 A. The desired imine can be removed from the product E,xamples of such polyhalothioketones are octafIuoro-2-butathione s CF3-C-CF2-CF3 30 ,tetradecafluoro-4-heptathione s 11 CF3-CF2-CF2-c-CF2-CF2-CFa, hexafluoro-2-propa,thione 35 s 11 CF3-C-CF3 4II-heptafluoro-2-butathione 40 HCFz-CF2-C-CFS 1-chloroheptafluoro-3-butathione s 11 Cl-CF2-CF2-c-CF3 .15 and the like. The above are known compounds, prepared as described in U.S. Patent 2,970,173 by any of the following: (1) reacting a secondary polyfluoroalkyl iodide of at least three carbons in the alkyl group with a phosphorus 50 polysulfide, e.g., P2S5 Or P4S3, in the liquid or vapor state at elevated temperatures; (2) heating a polyfluoroketone with phosphorlis pentagulfide for several hours at 200' to 300' C. under autogenous pressure; 55 (3) reacting a secondary perfluoroalkanethiol with a hydrogen fluoride acceptor, e.g., sodium fluoride; (4) reacting sulfur with a perfluoroolefin of at least three carbon atoriis at 400' to 650' C; or (5) thermal decomposition of selected po lyfluorinated 60 dithietanes at 450' to 700' C. A method for preparing alkylideneimines of the forniula NX 11 135 R-CF2-C-CF2-R, in which the R!s are as ;already defined and X is alkyl or cycloalkyl, comprises a two-step process which is, in part, schematically represented as follows: 70 0 OH 11 R-CF2-u-u -L, 2-it- -@- -L'4112X -- R-CF2-C-C F2-R, I mixture either by permitting it to distill off during the dehydration step or subsequently distilling the product mixture. The imine can then be purified by fractional distillation. A method for preparing N-aryl-al-kylideneimines of the formula: N-aryl 11 nU I' 2-U-C F2R' in which R and R' are as already defined comprises reacting a polyfluoroketone with an aryl isocyanate, in accord -with the equation: R-CF2-C-CF2-R' + aryl-N=C=O CsF 11 0 R-CF2-C-CF2-R' + C02 11 N-aryl The above synthesis is illustrated by the second part of Example IV. Examples of arnines and hydrazines usefully employable in converting the alkylideneimines to the products of this invention are ammonia, cyclohexylamine, methylcyclohexylamine, ethylamine, butylamine, hexylamine, d@decy@amine, octadecylamine, aniline, a-naphthylamine, piperazine, hydrazine, N-methylhydrazine, N-phenylhydrazine, N,N-diphenylhydrazine, N-naphthylhydrazine, N,Ndinaphthylhydrazine, and the like. It is obvious that the heretofore disclosed alkyl amines, aryl amines, and lalkyl, alkylamino, haloalkyl, hydrohaloalkyl, aryl, and arylamino substituents containing seven or fewer carbon atoms are lea:st expensive and most available, and to that extent preferred. But there is to be no question of the operability of, or of the intent to disclose and include within the present invention, any arylamine or aryl or arylamino substituent of up to 14 car@bon atoms and any alkyl amine, or alkyl, alkylamino, pherhaloalkyl, or w-hydroperhaloalkyl group of -up to 18 carbon !atoms. The widest variation of cdmpounds or groups within this definition does not in any way detract from the fundamentail characteristics of either the prbduct or of the process features of the present invention. The exa@mples which follow are intended to illustrate, but do not li-rnit, this invention. EXAMPLE I s N-H 11 11 C F3-C-C F3 -F TIN3 - C F3-C-C Fa + S + N2 One hundred milliliters of IN hydrazoic acid in chloroXNH 75 form was cooled to -15' C. and 18.2 g. (0.1 mole) of
[3]5 hexafluorothioacetone was added dropwise. A vigorous evolution of nitro-,en occurred. The blue color faded and a yellow precipitate forined. The reaction mixture was then warmed to 50' C. in 5 to 10 minutes and the gases that evolved were condensed in an ice-cooled trap. The condensate was distilled tlirough a spinning band still to give 5 ml. of hexafluoropropylideneimine as a colorless liquid, B.P. 15 to 17' C., contaminated with about 6% of choloroform, as determined by vapor-phase chromatographic analysis. A purer sample of hexafl uoroisopropylldeneimine was iprepared by substituting chlorobenzene and tetra@chloroethane, respectively, for the chlor(>form, but in both cases a lower yield was obtained. The pure imine bas a B.P. of 16-16.5' C., M.P. Ca. -47' C., doli ca. 1.51. Nuclear magnetic fresdnance, infrared, and mass spectro,-raphic data are consistent with the assignment of the str,ucture NH 11 OF3-c-CF3 to the product. Analysis.-Caled, for C3H-F6N: C, 21.83; H, 0.61; F, 69.07; N, 8.46. Found: C, 21.81; H, 0.76; F, 68.81; N, 8.16. Hexafluoropropane-2,2-diamine NH NH2 11 CF3-C-CF3 + NH3 @ CFZ-C CF3 I NH2 Ammonia, 8.5 g. (0.5 -mole), was distilled into a flask cooled in an ice bath and containing 39 g. (0.25 mole) of hexafluoroisopropylideneimine, prepared as described, above. After the addition, the mixture was refluxed for five minutes and then distilled. There was obtained 42.5 g. of hexafluoropropane-2,2-dianiine as a colorless liquid, 25 1.3229. B.P. 91-91.5' C., nD Analysis.-Calcd. for C3H4F6N2: C, 19.79; H, 2.21; N, 15.39; F, 62.61. Found: C, 20.11; H, 2.28; N, 15.82; F, 62.27. EXAMPLE 11 NH CF3 11 CFa-C-CF3 + NH3 - li2iN-U-NH2 1 uF3 Ammonia, 0.1 ml., was added to a Tefluxing solution of 5.5,ml. (0.05 mole) of hexaflurorlsopropylideneimine, prepared as in Example 1, in 15 ml. of diinethyl ether. Since no visible reaction occurred after one hour, an additional I ml. of ammonia was added. The mixture then became yellow and a solid formed. The reaction mixture was stirred under reflux for two hours. The solvent was evaporated and the residue was distihed to gi-ve 4.48 g. of hexafluoropropane-2,2- diamine,as a colorless liquid, B.P. 91' C. M.P. 20.5' C., nD2!.5 1.3329. Ana -Cal,,:d. for C3H4F6N2: C, 19.79; H, 2.21; F, 62.61- N, 15.39. Found: C, 20.38; H, 2.31; F. 62.75; N, 15.66. The infrared specram indicated the presence of NH2 at 2.92p& and 3.OA. Both the fluorine and hydrogen ii-m-r spectra contained a sin.-le unsplit Tesonance lineEXAMPLE HI 1,3-dichloro-1,1,3,3-tetrafluoro-2,2-propanediamiize NH N]12 CF2CI-C-CF201 + NH3 - CFgCl-C-CF2CI I NH2 Ammonia, 6.6 mil., at -78' C. (about 0.3 mole) was distilled into a flask containing 39.6 g. (0.2 mole) of 1,3 - dichloro-1,1,3,3-tetrafluoroisopropylideneimine, prepared ias described in Table 1. The reaction niixture was aeowed to reflux under a solid carbon dioxide cooled condenser for two hours and then distieed. There was obtained 38.3 g. of1,3-dichloro-1,1,3,3-tetrafluoro-2,2- propanediamine as a colorless oil, B.P. 44.5-450 (10 mm.), 3,326,976 6 nD 25 1.4105. The F'9 ii-m-r spectrum contained a single peak at -214 c.p.s. relative to Freon@. Analysis.-Calcd. for C3H4Cl2FIN2: C, 16.75; H, 1.88; Cl, 32.98; F, 35.36; N, 1303. Found: C, 17.01; H, 1.94; Cl, 32.82; F, 35.29; N, 12.37. EXAMPLE rV N - phenyl-1-1,3-dichloro-1,1,3,3-tetrafluoi-o-2,2-propanediamine 10 NA EINO 11 CF2CI-C-CF2CI + NH3 @ CF2CI-C-CF2cl I NH2 Ammonia, 2 ml., at -78' C. was slowly distired into 15 13.4 g. (0.049 mole) of N-,phenyl-1,3-dichloro1,1,3,3tetrafluoroisopropylideneimine, prepared as described bellow, and the reaction -mixture was stirmd overnight. The briglit yellow color of the reaction mixture faded during this time. Distillation gave 10.8 g. of N-phenyl-1,3-di20 chloro-1,1,3,3-tetrafluoro-2,2-propanediamine as a colorless oil, B.P. 79-80' C. (0.3 mm.), nD@5 1.4983. The proton n-m@r spectrum showed a multiplet at 3.08 r (area 5) and singlets at 5.99 T (area 1) and 8.16 r (area 2). 25 An@alysis.-Calcd. for C9H8Cl2F4N2: C, 37.14; H, 2.77; Cl, 24.39; F, 26.12; N, 9.62. Found: C, 38.01; H, 2.89; Cl, 23.63; F ' 25.05; N, 9.84. The N-phenyl-1,3-dichloro - 1,1,3,3-tetrafluoropropylideneimine used in the above experiment was prepared 30 as follows: A 240 ml. Hastelloy reactor was charged with 10 g. of cesitim fluoride, 100 g. (0.5 mole) of S-dichlorotetrafluoroacetone, and 50 g. of phenylisocyanate. The charge was heated at 1000 C. for 2 hours, at 125' C. for 2 hours, 35 and 150' C. for 8 hours. Thereafter the reactor was permitted to cool to ambient temperature, vented to the atinosphere, disrharged, and the residual liquid distilled. From the distillation there were recovered 10.5 g. of a yellow oil, B.P. 72 to 73' C. (5.5 mm.), nD 25 1.4750. The 40 infrared spectrum contained a band at 5.92,u for CN, and the fluorine n-n2-r (56.4 mc.), when determined on a cold sample, showed two triplets centered at -775 c.p.s. and -602 c.p.s. (J. 19 c.p.s.) shifted from Freon 112@. The analytical data indicate that the product, obtained 45 above, was N-phenyl-1,3-dichloro - 1,1,3,3-tetra fluoropropylideneimine formed according to the equation: 0 11 OF2cl-,C-CFgCl + CoHs-N=C=O 50 N-C6Hs CF201-C-CF3CI + C02 EXAMPLE V ]-(1,1,1,3,3,3-hexafluoro@2-phenylamino@propyl)hy55 dr azine CF3 C6H6NH CF3 C OH5N=C + H2NNH2 C OF2 H2N-NH CF3 60 TO a stirred mixture of 1.1 ml. (ca. 1.1 g.) of anhydrous hydrazine in 25 nil. of ether at room temperature was added a solution of 8.6 g. of N-phe nylhexafluoropropylideneimine, prepared as described subsequently, in 25 ml. of ether. A slight exothermic effect was noted and 65 the solution refluxed -ently. The mixture was heated under reflux for two hours, at which point solid had separated an the walls of the flask. The addition of an additional 0.2 ml. of hydrazine gave no apparent change. The mixture was evaporated to dryness and the,white solid Yesidue 70 was treated with pentane and filtered to give 6.41 g. of pale Yellow crystalline 1[1,1,1,3,3,3-hexaftuoro - 2-phe nylamino)-propyl]-hydrazine, M.P. 76.3-77 ' 9' C. A second crop of 1.64 g., M.P. 77.5-78.31 C. (total 8.05 g., 83% conversion) was obtained by cooling the filtrate. Two re75 crystallizations of the first crop fr@o@m ether/pentane using
[4]7 activated carbon gave a coloi@less crystalline product, M.P. 74.2-74.7' C. Infrared spectrum: 2.95, 3.06, 3.14, 3.19A (NH and NH2); 3.24, 3.8,8t4 (=CH); 6.21, 6.43, 6.47A (NH2 and arom. C=C); strong absorption 8-9,u for C-F; 13-29, 14@391A (monosubstitlited aromatic). Proton n-m-r spectrum (in CHC12): 2.887 (arom. H, 5X peak); 5.74,r (broad) and 6.63,r (sharp) of equal size for NH and NH2. Fluorine n-m-r spectrum (in ether): single resonan@ce for CF3. Titration in ethanol-water with O.lN NAOH showed buffering at pH 3.5-4.5 and a neutral equivalent of 276. Analysis.-Caled. for C9H9F6N3: F, 41.8; N,'15.4; N.E., 273. Found: F, 41.74; N. 15.06; N.E., 276. , The- N-phenylhexafluoroisopropylideneimine used in the above experiment was prepared as follows: A 240 ml. Hastelloy pressure reactor was char.-ed with 24 g. of phenylisocyanate and 4.8 g. of powdered cesium fluoride (tube precooled, N2 atm.) and then 50 g. of hexafluoroacetone was added. The mixture was thereafter heated under autogenous pressure at 100' C. for 2 hours, at 125' C. for 2 hours, and at 150' C. for 8 hours. The reactor was allowed to cool, and 16 g. of v6latile product was collected in a stainless steel cylinder. This material was found by infrared and gas chromatographic analysis to contain carbon dioxide as the major component, alon.with unreacte-d hexafluoroacetone. The non-volatile product, 53 g., was filtered, and the filtrate, 39 g., @on distillaiion with a spinning band column gave 35.9 g. (75% conversion) of Nphenylhexafluoroisopropylidencimine as a yellow liquid, 13.P. 48 to 50' C. at 22 mm. The inftared spectrum showed bands at 3.26 (CH), 6.25, 6.30, and 6.70A (arom. C=C), 5.78A (C=N), 13.24 and 14.46/L (monosubstituted benzene),and strong absorption in the 8/i, region (CF) in support -of this structure. The UV spectrum in etbanol showed k3420A=5.95 and k233OA-13.5 The fluorine n-nz-r spectr-um (56.4 mc@, "Freon 112" ref.) showed two resonances in the CF3 region at -255 and +245 c.p.s. The proton n-m-r resonance showed several peaks in the aromatic region, 400 to 350 c.p.s. from (CH3)4Si at 60 me. I Analysis.-Caled. for C9H5F6N: F, 47.3; N, 5.81. Found: F, 47.19; N, 5.79, 5.87, 5.64. EXAMPLE VI 2-amino--],@1,1,,,3,3,3-hexafluoi-o-2-propylhydrazine NH NHNH2 11 CFa-C-CF3 + N112NH2 - CF2-C-CFs NHs Helxafluoroisopropylideneimine, prepared as described in Exarnple 1, 33 g. (20 ml. at -10' C., 0.2 mole), was slowly distilled into a flask containing 6.4 g. (0.2 mole) of hydrazine. The reaction mixture was cooled in an ice bath during the addition. - Distillation at reduced pressure gave 33.7 g. of 2-amino-1,1,1,3,3,3-hexafluoro-2-propylhydrazine as a colorless liquid, B.P. 73-74' C. (45 mm@), ill) 25 1.3565. The F'9 n-m-i- (56.4 me.) showed a singlet at 635 c.p.s. from Freon 112@ and the proton n-m-r (60 inc.) showed three broad singlets at 5.6 r (area 1), 6.5 r (area 2), and 7.5 T (area 2). . Analysis.-Calcd. for C3H5F6N3: C, 18.31; H, 2.56; F, 57.84; N, 21.32. Found: C, 18.57; H, 2.67; F, 57.68; N, 21.59. EYAMPLE VII 2-amino-2-ph,enylamino-1,1,1,3,3,3-hexafluot-opropWne HN-0 OF,-C-CFa + NH3 @ CF3C-CF3 I Nrf2 3,326,976 Ammonia, 5.g., was slowly distihed into a flask connected to a solid carbon dioxide-cooled reflux condenser and containing 18.4 g. of stirred Nphenylhexafluoropropylideneimine, prepared as described in Example VI. The yellow color of the reaction mixture faded near the end of the addition. The reaction mixture was distilled to give 17.1 g. of 2-amino-2- phenylamino-1,1,1,3,3,3,-hexafluoropropane as a colorless liquid, B.P. 48' C. (0.4 mm.), nD25 1.4392. The infrared spectrum contained bands at 10 2.93g 2.98g and 3.lA for NH and NH2, The proton n-m-r showed a multiplet centered at 3.0 7 (area 5), a singlet at 6. 10 r (area I) and a singlet at 8.23 r (area 2). Analysis.-Calcd. for C9H8F6N2: C, 41.86; H. 3.13; F, 44.16; N, 10.85@ Found: C, 42.44; H, 3.14; F, 44.23; 15 N, 11.44. EXAMPLE VIII 2-tn@ethylamino-2-dimethylaininoperfluoropi-opane 20 CF3 I CFa-c-CF3 + HN(CH3)2 @ (CH3)N-C-NHCH3 CF3 25 A mixture of 1.8 g. of N-methylperfluoroisopropylideneimine, prepared as described subsequently, and 2 ml. of dimethylamine was heated at reflux for 10 minutes and then distilled. There was obtained 1.5 g. of 2-methyl30 amino-2-dimethylaminoperfluoropropane as a colorless liquid, B.P. 58-59' C. (100 min.). Analy-yis.-Calcd. for C6HIOF6N2: C, 32.13; H, 4.50; F, 50.88; N, 12.49. Found: C, 32.87; H, 4.61; F, 51.20; N, 12.07. 35 The N-methylperfluoroisopropylideneimine used in the above experiment was made as follows: 0 40 11 CF3@-C-CF3 + NH2CH3 OH N-CHS 1 POC13 11 [CF,-C-CF3] Cpa-c-CF3 1 NHCH3 45 Ilexafluoroacetone, 26 ml., at -78' C. (0.25 mole) was distilled into a flask containing 125 ml. of pyridine cooled to -25' C. Methylamine, 12 ml. at -1(' C. 5o (0.25 mole), was then distilled into the reaction mixture, keeping the temperature between -20' C. and -30' C. The reaction mixture was then allowed to warm to room ternperature, and 25 ml. of phosphorus oxychloride was added dropwise over a period of 30 minutes. The mixture 55 warmed spontaneously and be.-an to boil. The evolved gases were condensed @in a trap cooled by solid carbon dioxide. The reaction mixture was heated to 90' C. for one hour. The condensate was distilled to give 39.3 g. (87% yield) ofN-methyl-1,1,1,3,3,3- hexafluoroisopropyl6o ideneimine as a colorless liquid, B.P. 34-35' C.; nn25 1.3. The infrared spectrum of this imine contained a band at 5.87/j,. The F19 n-m-r (56.4 mc.) spectrum contained two quartets (J=8 c.p.s.) further split to doublets (J=2.5 c.p.s. and J=1.8 c.p.s., respectively) centered at -17 65 c.p.s. and +345 c.p.s. relative to 1,2-difluoro1,1,2,2tetrachloroethane an 0 A7ialysis@Caled. for C4H3F6N: C, 26.82; H, 1.69; F, 63.67; N ' 7.83. Found: C, 27.94; H, 1.98; F, 63.76; N, 7.66. 70 The hexafluoropropane-2,2-diamine u-sed in the aboveexperiment was made as described in Example II. In the right column of Table I are listed the products that are obtained when the thioketones listed in the left column are substituted f4Dr the perfluorothioacetone of 75 Example I in the process of Example 1.
[5]9 TABLD' I Reactants Products NH 11 CFS-U-CFiCFs +HNs @ CF30CF30F: s NEE 11 CiFT--LI-CIFI, + NHa - C3F7-c-c5Fll s NEE 11 HCF2CFI-C-CFi + HNs - HCFjCFr-8-CF3 s NH 11 11 CICFiCFt-C-CFs + HNs @ CICF2C I-C-C s NH CF3Cl-@l-CF2CI +HNs @ CFjCl-@l-CFICI NH C7Fir-C-C7Fis + HN3 - C7F,s-c-c7F,s In the right column of Table II are listed the diamines that are obtained when the imines listed in the left column are substituted for the h exafluoroisopropylideneimide of Example I in the process of Example 11. TABLEII Reantants Products NH NH2 11 1 CFA-C-CiFa + NHs, CFa-C-C2Fa NH NH2 11- I C:FT--c C&FI, +NH3 C3F7--c-C5Fll I NH3 NH NHi 11- HCF2CF%--c CF3 + NH3 HCF2CFr-@-CFs I NRi NH NHi 11 1 ClCFSCFS-C-CFs + NHs @ ClcF3cF3-C-CF: @Hs NH NHi 11 CF2C@u-CFICI + NH3 - CF2Cl-c-cF3cl kH2 NII NH2 11 I C7F,5-c-C7F,o + NHs - C7Fir--C-C7Fzs 1 NH2 The new diamines of this invention are useful as polymer intermediates and as inhibit4ars in vinyl-type polymerizations. Thus, they react with diisocyanates to give polyureas which have valuable properties and inhibit the polymerization of styrene, as illustrated below: CF3 I N(02H5)3 H2N-C-NHi + OCN-<::_:@-CHi @F3 NC 0 CFAH 0 H -c-N-C-N CH3 @Fal -1@@>- N-CJ. A mixture of 182 mg. (0.001 mole) of hexfluoropropa ne-2,2-diamine, prepared as in Example II, 179 mg. (0.001 mole) of toluene-2,4-diisocyanate, and lone microdrop of @riethylamine was heated for 5 hours. On cooling, a light yellow, extremely viscous liquid was obtained. Th@is product gave a strong bond between two pieces of wood illustrating that it is useful as a laminated adhesive. A solution of 20 g. of freshly distifled styrene in 50 ml. of benzene containing 0.1 g. of a,m'-azodiisobutyronitrile was heated at reflux for five hours. Extensive polymerization occurred. The experiment was repeated with the addition of 1 g. of perfluoropropane-2,2-diamine, prepared as in Exam3,326,976 10 ple 11, to the benzene solution. No polymerization occurred after five hours of heating. Similarly, I g. of N-phenyl-1,3-dichloro-1,1,3,3-te trafluoro-2,2-propanediamine inhibited the polymerization of 20 g. of styrene. As many widely different embodiments may be made with6ut departing from the spirit and scope thereof, it is to be understood that this invention is not limited to the specific embodiments thereof except as defined in the ap10 pended claims. The embodiments of the invention in which an exclusive property or privilege is
