DE1418313A1 - Process for the preparation of perfluoroalkylalkanols - Google Patents

Description

Minnesota Mining and Manufacturing Cumpany, St. Paul, Minnesota, V.St.A. ;

Process for the preparation of perfluoroalkylalkanores

The invention relates to a method of making Perfluoroalkylalkanols.

Perfluoroalkylalkanols are already known in which the carbon atom carrying the hydroxyl group has two hydrogen atoms, while the other carbon atoms are completely fluorinated, that is to say 1,1-dihydrogen perfluoroalkylalkanols. These alcohols are produced by reducing perfluorinated aliphatic monocarboxylic acids of the formula ^c _I v ^F 2n + 1 ~ ⁱ '' ^00I * ^{> of the} carboxylic acid chlorides or the methyl esters with lithium alanate. They have pronounced oleophobic and hydrophobic properties, but are to a certain extent soluble in organic solutions.

909834/1439

Urüeriagen ^ ⁷ ^ ^{J At} · - · * ^No · '

· · ^; fj ³

-2- M 743

The invention relates to a process for the production of PerfluoroalkylalKanolen, and is characterized in that for the production of u) -perfluoroalkyl-substituted alkanols with up to 12 methylene groups per molecule, the perfluoroalkyl radical having 3 to 12 carbon atoms, the corresponding perfluoroalkylsulfonyl halides in the presence of a peroxide catalyst in is catalytically reacted in a manner known per se with unsaturated alcohols or the corresponding perfluoroalkylsulfonyl halides are reacted with unsaturated acids or their esters in a manner known per se and the reaction products formed are reduced to the alcohol in a manner known per se.

It has been found that the terminally or &) -perfluoroalkyl-substituted alcohols prepared according to the invention, in which a chain or pressure containing up to 12 ethylene groups is arranged between the perfluoroalkyl radical and the hydroxyl group, have particularly favorable properties for reducing the surface tension in aqueous Own systems.

According to the invention, the O) -perfluoroalkylalkanols are prepared by reducing the halogen-substituted perfluoroalkylalkanols which are produced by the addition of perfluoroalkanesulfonyl chlorides . with SOp escaping to unsaturated oil canols, such as allyl alcohol and its homologues, as shown in the following equation:

BAD ORlOIMAL 909834 / U39

K18313

-3- M 743

CH ₂ = CH-GH ₂ UH catalyst

iiauH

Analogous corresponding addition reactions of perfluoroalkanesulfonyl halides with unsaturated esters and acids and subsequent reductive elimination of hydrogen halide also lead, according to the invention, to <iJ-perfluoroalkylalkanols, either by saponifying the esters obtained or reducing the corresponding Cd -perfluoroalkylsubstituted aliphatic aluminum acids or their esters, e.g. with lithium aluminum hydride .. These conversions are explained by the following equations: - - - ".

H-CiO ₉ -Cl + GHpsCH-CHp-CHpO-CO-CHo - ^ B-CH ₉ -CHCI-CH ₉ -O-Co-CH '!

Raney nickel, - H ₂ , alkali / Kf (CH ₂ ) ₄ -Ü-Cu »CH ₃ - ^ H _f (CH ₂ ) ₄ -0H

R _f -üü ₂ -Cl + CH ₂ = CH- (CH ₂ ) ₈ -C0 ₂ H - φ H _f -CH ₂ CHC1- (CH ₂ ) ₈ -CO ₂ E _:

Raney nickel, R ₉ , alkali / 1 ^ - (CHp ₁₀ -CO ₂ H ^ ier NaBH ^ H ^ - (CH ₂ ) _1Q -CH ₂ 0H

Examples of i-perfluoroalkyl-substituted to be prepared according to the invention ^ ilkanols' with up to 12 methylene groups are 3- (perfluorooctyl) propanol, 12- (perfluorobutyl) -dodeQan-1-ol, 6- (Perfluurdecyl) -hexane-1-pl,

BATH 909 834 / U39

H18313

- 4 - M 745

5- (perfluoropropyl) -pentan-1-ol, 12- (perfluorododeeyl) -dodeeanl-ol and 7- {perfluoroetyl) -heptan-1-ol.

example 1

A mixture of 26/8 g (0.052 mol) of perfluoro tansulfony 1 chloride and 5.0 g (0.050 mol) of 4-pentenoic acid (allyl acetic acid) is in the presence of about 120 ° to 145 ° C. for 4 hours a catalytic amount (1.0 g) of di-tert-butyl peroxide am Heated to reflux. The reaction mixture is reduced under reduced temp Pressure fractionally distilled and the at 100 ° C below The fraction boiling 0.01 mm is collected. After recrystallization the 4-chloro-5- (perfluoroethyl) pentanoic acid obtained melts from a mixture of chloroform and carbon disulfide at around 89 - 90 ° C.

The 4-chloro-4- (perfluoroetyl) pentanoic acid produced in this way is obtained by shaking a solution of 8.00 g (0.0145 mol) of acid and 2.5 g for 3 hours <0.062 mol) sodium hydroxide in a mixture of 50 ecm water and 50 ecm A * 1äianol at 14o ° C in a high-pressure vibrator reservoir in

2 Presence of 4 g Raneyniekel with hydrogen below 175 kg / cm hydrogenated. After the catalyst has been separated off and evaporated to dryness, an amorphous residue of sodium 5 ~ (perfluoroethyl) pentanoate is obtained obtain. By dissolving this residue in water and then acidifying the resulting solution becomes the saturated aliphatic chain formed by hydrogenation Perfluoroalky! Carboxylic acid as a waxy white solid substance

909834/1439

obtained, which are distilled at 100 ° C below 0.02 mm can. After recrystallization from carbon disulfide the 5- (perfluorooctyl) pentanoic acid obtained melts about 86.5 ° to 87.3 ° C.

A suspension of 30 parts of 5- (perfluoroethyl) pentanoic acid in ether becomes a solution of 3 parts of lithium aluminum hydride given in about 200 parts of anhydrous ether. The reaction mixture is stirred for about 48 hours and then with Treated water and neutralized sulfuric acid The reaction mixture is extracted several times with ether and the ether extracts are combined, dried and in vacuo fractionally distilled. 5- (PeiQ-uorooctyl) pentanol, which is used in boiling about 108 ° C below 2.5 mm was obtained.

In the same way, 10-indenoic acid is used instead of allyl acetic acid II- (perfluorooctyl) undecanoic acid obtained, which after reduction lI- (perfluorooctyl) -undecanol, which boils at about 122-126 ° C below 0.10-0.15 mm Hg, results.

Example 2

About J g of di-tert-butyl peroxide are added to a mixture of 80 g of perfluoroetylsulfonyl chloride and J51 g of allyl acetate, and the reaction mixture is slowly heated to about 80.degree. C., whereupon the temperature rises spontaneously to about 130.degree. After this reaction has subsided, will

909834/1439

1413313

- β - H 145

a further amount of di-tert-butyl peroxide was added. It is heated for a further 14 hours to about 110 ° C with further addition of peroxide after about 8 hours. The reaction mixture is then fractionally distilled in vacuo and the 2-chloro-5- (perf luoroc ty 1) -ally laoe tat, which has been gefcLldet in the reaction, as a fraction between 155 ° and 158 ⁰ C at 37 mm pressure. A little more than the theoretical amount of sodium methylate in methanolic solution is added to a solution of 50.5 g of this substance in 50 ecm of anhydrous methanol, which contains phenolphthalein as an indicator. The reaction mixture becomes pale reddish and sodium chloride precipitates. After 48 hours of standing at room temperature, the reaction mixture is treated with about 10 ecm of water and further sodium methylate and then heated to about 50 ° C. for about 4 hours. The organic phase is then removed and fractionally distilled, the fraction above the range of 129 14 ° C. being collected at 37 mm. The 3- (perfluorooctyl) allyl alcohol obtained in this way has the refractive index ■ -n ^ = 1.3328. A mixture of 42 g of 3- (perfluorooctyl) allyl alcohol, 1.8 g of Raney nickel, 45 ecm of ethanol and 1 g of potassium hydroxide is placed in an autoclave and hydrogen is injected under 15Ο atmospheric pressure. The hydrogenation to the corresponding saturated alcohol taking place can be recognized by a pressure drop within about an hour. The contents of the autoclave are filtered, and the filtrate is fractionated in vacuo. 3- (Perfluoroc tyl) propanol is obtained, which at a

9 0 9 8 3 A / U 3 9 _{BAD omGmAL}

kis l43 °

- 7 - M 7 * 3

l43 ° C boils under 38 mm pressure and the expansion

24

index n ~ s = 1., 3JJ12 has. The infrared spectrogram of this sub punch indicates that it is completely saturated.

Example 3

Approximately equimolar amounts of ethyl perfluorobutyrate, methy lace tat and sodium methoxide are used. The ethyl perfluorobutyrate is added to a cooled solution of sodium methoxide in absolute liquid with further cooling. After this mixture has been stirred for about 2 hours, the methyl acetate is added, whereupon a clear solution forms. The solution is stirred for about 16 hours and then fractionated under reduced pressure, distilled to remove the solvents, giving methyl 3 ~ (perfluoropropyl) ~ 3-keto-propionate as the main product. The keto ester obtained in this way is hydrogenated under pressure with Raney nickel in an ethereal solution under the usual conditions for about 2 hours. The catalyst is filtered off and the filtrate is fractionally distilled in vacuo, whereupon methyl 3- (perfluoropropyl) -j5-oxypropionate, which boils at about 85 ° G under 15 mm pressure and has the refractive index nj ^ = 1.3513 is obtained. About 157 parts of the hydroxy ester obtained in this way and 175 parts of phosphorus pentoxide are mixed and left to stand for about 16 hours (a rather strong exothermic reaction occurs shortly after mixing). The reaction mixture is then filtered and the filtrate is purified by fractional distillation. Meäiyl-3- (perfluoropropyl) acrylate is

909834/1439

. ■ ■. - 8th - . M 743

hold that at 121 -124 ° C at 732 mm pressure: boils and has the refractive index n ^ = 1.3362. The acrylic acid ester is hydrogenated in ethereal solution with Raney nickel under high pressure and under the usual conditions. The reaction mixture is filtered and the piltrate is fractionally distilled under reduced pressure. The corresponding saturated ester, methyl 3- (perfluoropropyl) propionate, which boils at 42 ° C. under 12 mm pressure and has the refractive index n ^ = 1.3276, is obtained.

To a solution of 7 * 6 g (0.2 mol) of lithium aluminum hydride , in 500 ecm of ether are 49 g (0.101 mol) of methylene 1-3- (heptafluoropropyl) propionate, Dissolved in 100 ecm of ether, added so quickly that the solution boils vigorously at reflux. The mixture is then stirred for 1 hour and an excess of methanol is added to hydrolyze the complex. The reaction mixture is then acidified with dilute sulfuric acid. The ether layer is separated and the aqueous layer again extracted with about the same volume of ether. The United Ether phases are evaporated to remove the ether and the residue is fractionally distilled. This here The 3- (heptafluoropropyl) propanol obtained boils at about 14o 14 ° C at 745 mm pressure and has the refractive index Πρ = 1.3270.

Pat tans claims:

90 9834 / U3 9

Claims (2)

- 9 - M 743 claims 1. Process for the preparation of perfluoroalkylalkanols, characterized in that for the preparation τοπ & J -perfluuralkyl-substituted alkanols with up to 12 ethylene groups per molecule, the perfluoroalkyl radical having 3 to 12 cooling atoms, the corresponding perfluoroalkylsulfonylhalugeniue
in the presence of a peroxide catalyst in per se known
Catalytically reacted way with unsaturated alcohols or the corresponding perfluoroalkylsulfonyl halides with unsaturated acids or their esters in a manner also known per se
Way and the resulting reaction products in an
as is known, reduced to alcohol. 2. The method according to claim 1, characterized in that aass
the unsaturated alcohols used are allyl alcohol and its homologues. 909834/1439 'BATH