DE1294949B - Process for the preparation of perfluoroalkyl-alkyl-ethers - Google Patents

Description

1 2

It has been found that corresponding end products of the formula (1) which are perfluorinated on one side can be carried out

aliphatic ethers of the general formula (1) splitting off of hydrogen halide in known

j way in the corresponding perfluorinated vinyl ethers

I ^{f of} the general formula

CF ₃ - (CF ₂ VC- O - R ² (1) ⁵ R \

F CF ₃ - (CF ₂ ) "- CO-CH =

in which R) a trifluoromethyl group or an io

Fluorine atom, η is an integer from 0 to 6 and R ^{2 is} a

straight-chain or branched alkyl radical from 1 to are converted.

18 carbon atoms, the one in the «position or a suitable one, towards the reactants

more distant position to the oxygen bridge, substituted inert solvents are, for example, acetone, can be ated, means obtained when perfluoro 15 tetrahydrofuran, acetonitrile, preferably diglycol

carbonyl compounds of the general formula (2) dimethyl ether, dimethylformamide and dimethyl

sulfoxide.

Rf While one usually, as described above,

I (2) ben, proceed in such a way that one first uses the potassium fluoride

CF ₃ - (CF2) »- C = O ao added to the perfluorocarbonyl compound, with it

It is expedient to use the potassium fluoride in the inert ιοί η which RJ and _n the abovementioned meanings in suspension, but after addition of potassium fluoride one can also proceed in such a way that the compound is inert with respect to the reactants mentioned general formula (3) to add solvents with compounds of the general 35 of the potassium fluoride suspension and the formula (3) reaction by adding the Perfluorcarbonylverbin-

X - R ² (3) to get going.

The compounds produced according to the method

in which R ^{2 has} the meaning given above, narcotics and valuable intermediates for and X is a chlorine or bromine atom or an alkyl 30 production of narcotics and polymers.

sulfuric acid radical of the general formula (4) _,. . , "

^{& w} example 1

170 g of a methyl or ethyl group are reacted in a reaction vessel equipped with a stirrer, cold cooler and gas inlet where R ^{3 is} an alkyl group, preferably a pipe. '35' (1.35 mol) dimethyl sulfate, 80 g (1.38%) Mole) potassium

The radical R ² preferably contains 1 to 6 carbon fluoride and 250 g of diglycol dimethyl ether initially charged, substance atoms. It can, for example, be at room temperature with vigorous stirring

^ Jj, j QQQ cjj _ cjj _ cpj Q qq_ 166 g (1 mole) of hexafluoroacetone initiated. Man

²⁵² 'then warms the reaction mixture for 6 hours

Cyano or carbalkoxy group, by a halogen 40 to reflux temperature (about 45 ⁰ C). The reaction atom, preferably a chlorine or bromine atom, or product, together with part of the solution, will be substituted by an alkoxy group, preferably a methoxy agent in vacuo in traps cooled to -80 ° C or an ethoxy group. '-' ■ '- ■■ distilled and then a fractional distillation

Subject to the process .llation with regard to the quantitative proportions. To give 190 g Heptafluorisogemäß to implement entering Reaktionskompo- 45 propyl methyl ether of boiling point 29 ⁰ C, which it is one of components appropriate to 1 mole Perfluorcarbonyl- yield of 95 ° / ₀ of theory, based on the einverbindung the general formula (2-mentioned ) with set hexafluoroacetone corresponds. 1 mole of potassium fluoride and the intermediate formed in this way. . ₁

product with 1 mole of the compound of the all- JJ ei spie W

implement common formula (3). The potassium fluoride so in a suspension of 405 g (7 mol) of potassium fluoride can also be used in a 1.1 to 1.5 times molar excess in 1000 g (6 mol) of ethyl bromoacetate and 1400 g shot can be applied. The compound of diglycol dimethyl ether, which is in a stirrer, general formula (3) can be used in excess will. action vessel are located, are stirred vigorously

The addition of the potassium fluoride is expediently carried out at room temperature 800 g (4.80 mol) of hexafluoride initiated at temperatures between about -60 and about acetone. The mixture becomes within + 30 ° C, preferably between about -40 and about 4 hours heated to 80 ° C and 9 hours on this + 20 ° C, the implementation of the intermediate temperature is maintained. The resulting precipitate products containing the compounds mentioned are filtered off and the filtrate is fractionally distilled, general formula (3) at temperatures between 60. 1081 g of heptafluoroisopropoxyacetic acid are obtained, for example 30 and about 130 ° C, preferably between about ethyl ester boiling point 138 to 139 ° C, what a about 40 and about 80 ° C. Yield of 83% of theory, based on the

The reaction can be carried out in an autoclave, hexafluoroacetone, corresponds to be guided. . .

If, in accordance with the procedure, with compounds of Example 3

mentioned general formula (3) is implemented, In a with stirrer, cold cooler and gas inlet

where R ^{2 is} a /? - halogenated alkyl radical, for example a reaction vessel provided with a tube

Claims (3)

70 g (1.20 mol) of potassium fluoride and 250 g of solution contains 32 g of heptafluoroisopropyl vinyl ether produced by the boiling agent. The solvents used are a) aceto point 29 to 30 ° C. nitrile, b) diglycol dimethyl ether, c) dimethyl sulfoxide _R. . . . or d) dimethylformamide is used. At room temperature, 166 g (1 mol) of hexafluoroacetone are introduced into the mixture under vigorous stirring. 29 g (0.50 mol) of potassium fluoride, 77 g (0.50 mol). The reaction mixture is then heated. In the case of ethyl sulfate and 200 ml of diglycol dimethyl ether above a) or b), a reflux occurs at 60 and 70 ° C., respectively. After the car has been closed and evacuated during c) and d) without reflux to 90 ° C., 48 g can be warmed at room temperature with stirring. The stated temperatures were initiated 10 (0.42 mole) fluoracetyl fluoride and held for 9 hours for 12 hours. After the separation, the mixture was stirred at 60.degree. The crude product is filtered with precipitation, the filtrate is subjected to a 200 torr distillation fractionated into a receiver cooled to -80 ° C. Distilled on hepta and matured by fractional distillation, ethyl fluoroisopropoxy-acetic acid ester is obtained. 59 g of pentafluoroethyl-ethyl in the case of 5 ether with a boiling point of 26 to 28 ° C. are obtained, which is a yield of 85% of theory, based on the tri- a) 20 g (yield 7% of theory, based on a fluoroacetyl fluoride, corresponds. set hexafluoroacetone); Example 7 b) 55 g (yield 20% of theory, based on hexafluoroacetone used); ^ao ^ ^{n emem} w ith gas inlet pipe, thermometer and , Cold cooler equipped stirred flask will be 32 g c) 215 g (yield 79% of theory, based on ( _Oj 55 mol) potassium fluoride, 93 g (0.60 mol) diethyl hexafluoroacetone used); _{sulfate and 250ml} dimethylformamide submitted, d) 239 g (yield 88% of theory, based on what 83 g (0.50 mol) in the mixture with stirring hexafluoroacetone used). as perfluoropropionyl fluoride. To 6 hours of heating at 50 ° C, the reaction Example 4 mixture decomposed by steam distillation, the Crude product separated from the distillate, with various In a reaction vessel provided with a stirrer, cold condenser and gas inlet, warm sodium hydroxide solution, washed and separated, 70 g of ₃₀ and calcium chloride are dried. By fractional (1.20 mol) potassium fluoride, 149 g (1.20 mol) 1-brominated distillation, 57 g of n-heptafluoropropylpropane and 250 g of dimethylformamide are presented. Obtained in ethyl ether with a boiling point of 51 ° to 52 ° C., what this mixture is passed with stirring, 166 g (1 mol), a yield of 53% of theory, to hexafluoroacetone used at room temperature. The perfluoropropionyl fluoride related corresponds to. The reaction mixture is then set to 35 for 50 hours 75 to 80 ° C and then under vermin- Example 8 dertem pressure in at - 8O ⁰ C cooled falling off in a verde distilled with thermometer and reflux condenser. 15 g (0.26 mol) of potassium-nated distillation, 173 g of heptafluoroisopropyl-n-propyl fluoride, 33 g (0.26 mol) of dimethyl sulfate, 64 g (0.15 mol) of ether are made from the distillate through fractional stirred flasks Boiling point 67 to 68 ⁰ C obtained, which presented a 40 perfluorooctanoyl fluoride and 100 ml dimethylform yield of 76% of theory, based on one amide. The mixture is placed under intense hexafluoroacetone, corresponds. Stirring heated to 45 to 50 ° C for 24 hours. At- . -ic then the reaction mixture is adjusted to pH 7 to 8 Example 5 provided, steam distilled and the crude product Separated from the distillate in one with a stirrer, cold cooler and gas inlet. After drying, a reaction vessel provided with a conduit tube, 122 g of some calcium chloride is distilled on a small column (2.1 mol) of potassium fluoride, 507 g (2.6 mol) of 1,2-dibromo. After 5 g of first run from boiling point 140 to ethane and 500 g of dimethylformamide submitted. In 146 ⁰ C 54 g heptadecafluorooctyl-methyl ether, this mixture can be obtained, with stirring, 332 g (2.0 mol) of boiling point 147 to 149 ° C. The yield hexafluoroacetone initiated at room temperature. The 50 is 50.5% of theory, based on the reaction mixture used, then perfluorooctanoyl fluoride is used for 12 hours. 80 to 85 ⁰ C heated. The cooled reaction mixture is shaken with 21 ice water. The lower phase forming the patent claims is separated and with Calcium chloride dried. Through the following distillation process, one-sidedly per- lation will be 396 g of a fraction of the boiling point of fluorinated aliphatic ethers of the general 103 to 107 ⁰ C obtained, which is about 60% from hepta formula (1) fluoroisopropyl - /? - bromoethyl ether. The rest of RJ the fraction consists of glycol-bis- (heptafluoriso- | propyl ether) and dibromoethane. 60 CF ₃ - (CFg) _n - C - O - R ² (1) To a mixture of 168 g (3 mol) of powdered 1 Potassium hydroxide and 250 g of diethyl glycol are left at P 80 ° C with stirring 293 g of the mixture obtained in the manner described above are added dropwise. in which RJ is a trifluoromethyl group or a straight-chain or branched alkyl radical condenses in a cold trap con-a straight-chain or branched alkyl radical from 65 fluorine atoms, η an integer from 0 to 6 and R ^a through a reflux condenser kept at 30 ° C, η an integer from 0 to 6 and until nothing passes over . The crude product 1 to 18 carbon atoms, which is in the α-position or is purified by fractional distillation. Man a more distant position to the oxygen bridge can be substituted, means, characterized in that that one perfluorocarbonyl compounds of the general formula (2) CF ₃ - (CF ₂ ) ^ - C = (2) in which Rf and η have the meanings given above, after addition of potassium fluoride in a solvent which is inert with respect to the reactants with compounds of the general formula (3) X —R ^a (3) in which R ^{a has} the meaning given above and X is a chlorine or bromine atom or an alkylsulfuric acid radical of the general formula (4) R ³ - SO ₂ -O means in which R ^{3 represents} an alkyl group, preferably a methyl or ethyl group, is converted. 2. The method according to claim 1, characterized in that the reaction in acetone, Tetrahydrofuran, acetonitrile, diglycol dimethyl ether, Performs dimethylformamide or dimethyl sulfoxide. 3. Process according to Claim 1 and 2, characterized in that the compounds obtained in the reaction with compounds of the formula (3) in which R ^{a represents} a / J-halogenated alkyl radical are converted into the corresponding perfluorinated vinyl ethers by splitting off hydrogen halide.