DE2835480A1 - FLUORINE 1.3-DIENES, THEIR PRODUCTION AND THEIR USE - Google Patents

Description

28354? *

HOECHST AKTIENGESELLSCHAFT HOE 78 / F 922 Dr.SC/ba Gendorf plant

Fluorine-containing 1,3-dienes, their production and their use.

The invention relates to fluorine-containing 1,3-dienes, a process for their production and their use for Production of polymers.

It is known that in the reaction of 1,4-dihalo-2-alkenes dienes with conjugated double bonds are formed by dehalogenation with suitable metals [/ cf. "Methods of Organic Chemistry" (Houben-Weyl) Volume V / 1c, Pages 155 to 16OJ. According to previous knowledge - and as the cited reference, page 155, expressly noted - fluorine is used in such 1.4-dehalogenations not attacked. On the contrary, zinc generally even enables the selective elimination of geminal substances other halogen atoms bonded to fluorine.

It was therefore surprising to find that when 1-perfluoroalkyl-A-haloalkenes of the formula R ^ -CF ₂ -CR = CR -CR ^ RX are reacted with metallic Häbgenakzeptoren in polar, aprotic solvents with elimination of X and F the corresponding 1.3-diene can win in good yields.

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ORIGINAL

The invention thus includes i-fluoro-i-perfluoroalkyl-1,3-dienes the formula

wherein

R ₊ . means a perfluoroalkyl radical having 1 to 12 carbon atoms

12 3 4
and R ₁ R, R, R, which can be identical or different, for hydrogen, for an alkyl radical with 1 to 10 carbon atoms, for the cyclohexyl, phenyl, benzyl, naphthyl radical or for an alkylphenyl or alkylnaphthyl radical with an alkyl chain of 1 to 5 carbon atoms.

The invention further comprises a process for the preparation of a 1-fluoro-i-perfluoroalkyl-i.3-diene according to the above formula I, which is characterized in that a _{haloalkene of the formula R 1 -CF 0} -CR = CR -CR ³ RX, where R ^, R,

2 3 4
R, R ^ and R have the abovementioned meaning and X = Cl, Br or J, with at least the stoichiometrically calculated amount of a metallic halogen acceptor in the presence of a polar, aprotic solvent at temperatures of 40 to 150 ⁰ C is implemented.

The 1-perfluoroalkyl-4-haloalkenes of the above formula used as starting material can be prepared by methods known from the literature. For example, the 4-chloro-substituted compounds are obtained by treating the corresponding perfluoroalkyl-substituted, unsaturated alcohols with chlorinating agents [see J. Amer. Chem. Soc ^ 8J5 (1961), pages 325t to 3258 and Synthesis, 1977 , page 297J. The corresponding bromine and iodine compounds can be obtained from the 4-chloro-substituted compounds by substituting the chlorine with the aid of alkali metal bromides or iodides .

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ORIGINAL INSPECTED

Of the haloalkenes used in the process according to the invention the above formula as the starting compound

12 3 fertilize those are preferred in which R, R, R ^ and R, identical or different, H or a short-chain alkyl radical with 1 to 3 carbon atoms, in particular a methyl radical, and also a benzyl, tolyl, ■ naphthyl or in particular represent a phenyl radical. The perfluoroalkyl chain in these haloalkenes can be branched, especially in the form of an ether be methyl branched, but it is preferably straight chain. The products obtained are also corresponding of the formula I with the substituents mentioned are preferred.

The reactivity of the haloalkenes mentioned as starting compounds falls in the series X = J > Br> C1.

As metallic halogen acceptors within the scope of the invention Process used are mainly metallic zinc and magnesium. Calcium, Cadmium, iron or lead-sodium alloys are examples of other metallic halogen acceptors that are suitable are. Zinc is particularly preferably used in the form of an activated metal pair of zinc with a second metal .

Magnesium is used as the halogen-accepting metal, the process according to the invention is best performed that one or continuously adding the serving as the starting compound of the above formula haloalkene portionwise to ainer heated and vigorously agitated suspension of magnesium turnings in a dialkyl ether. The minimum temperature required for the reaction to start is expediently 40 to 60 ^° C. for iodides and 60 to 80 ^° C. for bromides. Chlorides react very slowly, even at temperatures above 100 ^° C.

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ORIGINAL

-Each- 283548)

In a similar form, the reaction can also be carried out with finely divided metallic zinc.

The conversion of the starting haloalkenes into the 1-perfluoroalkyl-substituted However, 1-fluoro-1,3-dienes of the formula I, including the chloroalkenes (X = Cl), are successful preferably with zinc, which is in the form of an activated metal pair. As a second component for such In principle, metal pairs are suitable for all metals that are more electropositive than zinc. Preferably are to name cadmium, lead, mercury and palladium. The concentration of the second metal should be 0.002 to 0.05 Gram atom, preferably 0.005 to 0.015 gram atom, based on 1 gram atom of zinc, are »particularly suitable are zinc-copper-metal pairs, their manufacture for example in "Methods of Organic Chemistry" (Houben-Weyl), Volume XIII / 2a, pages 570 to 573.

The zinc-metal pair is expediently used in finely divided form. To achieve optimal yields an excess of zinc is advisable. In general, an excess of 0.5 to 1 gram atom of zinc is recommended per mole of starting haloalkene.

As aprotic solvents in which the process according to the invention takes place, apart from those already mentioned, are suitable Dialkyl ethers, in particular dialkyl formamides, for example Dimethylformamide, or dialkyl sulfoxides, for example Dimethyl sulfoxide.

In a particularly expedient form of the process according to the invention, the Ausjangs halogen alkene becomes a heated zinc-copper suspension in anhydrous dimethylformamide was added with vigorous stirring.

The temperature required to start the reaction depends on the type of starting haloalkene and is between

030009/0152

ORIGINAL

40 and 120 ^° C., preferably between 40 and 100 ^° C. The reaction itself is exothermic, so that heat does not have to be added until the end of the reaction in order to complete it.

It is essential that the reaction take place under anhydrous conditions is carried out. In order to ensure the exclusion of moisture, it is expedient to use an inert gas atmosphere to implement.

As far as the 1-perfluoroalkyl-substituted 1-fluoro-1,3-dienes formed of formula I have a low boiling point, they can to the extent of their formation from the reaction mixture are distilled off. If the dienes mentioned have high boiling points, they are, if appropriate, after the reaction has ended after separating off the excess metallic halogen acceptor by filtration or centrifugation, after customary methods, for example by fractional distillation, isolated. .

The 1-fluoro-1-perfluoroalkyl-1,3-dienes according to the invention Formula I can be polymerized by customary processes, products with good thermal stability and high Chemical resistance can be obtained. The polymerization can be initiated photochemically or thermally or in the presence of radical-forming or cationic initiators are carried out.

Depending on the polymerization conditions, elastomeric or glass-like products are obtained which are consistently have very good oil and water repellent properties;

The elastomeric polymers can be prepared by customary methods vulcanize, products with the character! stika of synthetic rubber with high thermal resistance and good low-temperature elasticity.

030009/0152

ORIGINAL INSPECTED

Furthermore, the glassy poly-M-fluoro-i-perfluoroalkyl-1,3-dieneJ processed thermoplastically. In this way, they can be light and oxidation resistant Protective layers for metal surfaces are produced. In particular, the new polymers can be used to obtain of cable sheaths with good insulating properties and high dielectric strength.

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- ir '' -

3 28354 * 0

The following examples are intended to explain the invention in more detail. Carefully dried solvents were used in all examples and reactions were excluded made of moisture in a nitrogen atmosphere. The products were characterized by elemental analyzes, nuclear magnetic resonance spectra and infrared spectra. The proton resonance spectra were recorded at 60 MHz with tetramethylsilane as the internal standard, the fluororesonance spectra registered at 56.45 MHz with trifluoroacetic acid as an external standard.

Manufacture of the zinc-copper pair used;

1 g of copper (II) acetate (0.005 mole) is dissolved at 40 to 50 ⁰ C in 100 ml of dimethylformamide (hereinafter abbreviated as DMF) * Then, there was 35.5 g of zinc dust (0.5 gram atom) and 20 ml of glacial acetic acid, the mixture is stirred 30 minutes, the metal pair formed is filtered off and washed four times with 20 ml of DMF each time. If the further reaction in other solvents (e.g. dimethyl sulfoxide, di-n-butyl ether) is planned, these are used as washing liquids. The Zn / Cu pair is converted in a freshly prepared state in order to avoid a loss of activity due to aging.

Making the 1.3 diene:

example 1

Preparation of 1-fluoro-i-trifluoromethyl-i.3-butadiene

A 250 ml four-necked flask is equipped with a stirrer, dropping funnel, internal thermometer and a distillation attachment, at the entrance of which there is a 5 cm long Vigreux adapter. The reaction vessel is charged with 35 g of Zn / Cu and 100 ml of DMF, heated to 85 ° C. and, with vigorous stirring, the dropwise addition of 48.6 g of C ₂ F ₅ —CH = CH — CH ₂ Cl (0.25 mol) is started. After adding about 5 ml

030009/0152

ORIGINAL

of the chloroalkene starts the reaction and the temperature of the mixture rises to 100 ^° C. The remaining chloroalkene is added just so quickly that the temperature ^{remains at 100 °} C. while the product is continuously distilled off and collected in a receiver cooled with dry ice. After the dropping is allowed to react for 30 minutes at 100 ⁰ C. The crude product obtained is purified by fractional distillation at normal pressure. As the main fraction obtained 27.4 g of a colorless, highly mobile liquid with a boiling point of 37 ⁰ C (yield: 78.3% of the theoretical amount).
Purity according to gas chromatographic analysis (GC) 98.9 %.

Analysis for C ₅ H ₄ F ₄ :

Calculated: C 42.87 H 2.88 F 54.25 Found: 43.0 3.0 53.7

¹ H-NMR: 6.88 to 6.30 ppm (multiplet, 1 H); 6.12 to 5.25 ppm (multiplet, 2 H).

^ F-NMR: shows 2 isomers A and B in the ratio 7. ^ ι 1.

/ " ¹ T Tr

J ^ C = C H = isomer A

F ^X C = C

H ^ H

58.0 ppm (doublet of quartets, 1 F), ³ JHF (trans) = 29.4 Hz, ³ JFF = 11.4 Hz; -9.0 ppm (doublet,

3 F).

FTT
η

C = C H = isomer B

H tt

030009/0152

At

53.1 ppm (1 F), ³ JHF (cis) = 19.2 Hz, ³ JFF = 9.0 Hz; -12.5 ppm (3 F).

IR: Tj (C = C) 1689 cm " ¹ (thick), 1615 cm" ¹ (medium).

Example 2

A suspension of 35 g of Zn / Cu in 100 ml of di-n-butyl ether is reacted in the manner described in Example 1 with 71.5 g of C ₂ F ₅ —CH =CH — CH ₂ I (0.25 mol). Redistillation of the crude product gives 23.3 g of 1-fluoro-i-trifluoromethy1-1.3-butadiene (66.5% yield). Isomer ratio A: B = 8: 1.

Example 3

A suspension of 9.72 g of magnesium turnings (0.4 gram atom) in 100 ml of di-n-butyl ether is reacted with 71.5 g of C ₂ F ₅ —CH =CH — CH ₂ I as in Example 1.

Yield of pure 1-fluoro-1-trifluoromethy1-1.3-butadiene: 19.0 g (54.3 90

Isomer ratio A r B = 7.5: 1.
Example 4

In the apparatus described in Example 1, the distillation head is replaced by a reflux condenser. A solution of 98.6 g of C ₆ F ₁₃ —CH =CH — CH ₂ Cl (0.25 mol) in 50 ml of DMF is added dropwise at 80 to 100 ^° C. with stirring to a suspension of 35 g of Zn / Cu in 100 ml of DMF and left react further after the addition for 1 hour at 100 ⁰ C. After cooling to room temperature, the mixture is stirred in 300 ml of water, the solid components are filtered off and the lower phase, which contains the majority of the product, is separated off in a separating funnel. The upper phase is extracted twice with 50 ml of diethyl ether each time. The ether extracts are combined with the lower phase and over magnesium

030009/0152

* "ORIGINAL INSPECTED

sulfate dried. Evaporation of the ether and fractional distillation gives 58.3 g of colorless, liquid 1-fluoro-1-perfluoro-n-penty1-1.3-butadiene with a boiling point of 65 ° C./80 Torr (yield: 68.6 %) .
Purity according to GC: 98.1 %

Analysis for C ₉ H ^ F ₁₂ :

Calculated: C 31.78 H 1.19 F 67.03 Found: 32.0 1.3 67.8

¹ H-NMR: 6.98 to 6.39 (multiplet, 1 H); 6.20 to 5.29 (multiplet, 2 H),

% -NMR: Vie for the trifluoromethyl compound (examples 1 to 3) stereoisomers also occur here, in the ratio A: B = 10: 1.

(A): 52.4 ppm O F); 49.0 ppm (2 F); 45.6 ppm (4 F); 40.6 ppm (2 F); 4.5 ppm (3 F).

(B): 47.9 ppm O (F); 49.0 ppm (2 F); 45.6 ppm (4 F); 37.7 ppm (2 F); 4.5 ppm (3 F).

IR: ^ (C = C-) 16 & 3 cm " ¹ (strong), 1615 cm" ^T (weak).

Example 5

In contrast to Example 4, dimethyl sulfoxide is used instead of DMF. Is added dropwise 109.5 g of C ₆ F ₁₅ -CH = CH-CH ₂ Br (00:25 mol) at 70 bis 80 ⁰ C to and stirred for 1 hour at 90 ⁰ C to react further. Working up as in Example 4 gives 36.0 g of 1-fluoro-i-perfluoro-n-penty1-1.3-butadiene (42.4 % yield).

Example 6

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ORiGFNAL

283548

When 52.1 g of C ₂ F ₅ -C (CH ₃ ) = CH-CH ₂ C1 (0.25 mol) are reacted _{analogously to Example 1, 30.3 g of the compound CF 3} -CF = C (CH ₃ ) -CH = CH are obtained ₂ obtained (78.7 % yield). Boiling point 70 ^° C. *> Purity (according to GC): 97.3 %.

Analysis for CgHgF ^:

Calculated: C 47.76 H 3.92 F 49.31 Found: 46.9 4.0 49.1 10

¹ H-NMR:

CF, ^ CH, 3 ^ 3

S 3

C = C yes. (A)

^H a ^H c

6.72 ppm (H »2 doublets of quartets), ³ JHg ₁ Hb = 16.7 Hz, ³ JH _a H _c = 10.5 Hz, ⁴ JH ₃ 1.7 Hz; 5.45 ppm (H _b , doublet); 5.31 ppm doublet); 1.83 ppm (CH ₃ ).

^^ H _b (B)

CF ₃ ^ C = C

^H a ^ ^Xh c

Differs from (A) only in the shift of H (6.80 ppm) and CH, (1.90 ppm), a j

¹⁹ F-NMR: (A): 53.5 ppm (1 F); -11.75 ppm (3 F), ³ JFF =

6.5 Hz. (B): ^p 0.7 ppm (1 F); -12.2 ppm (3 F), ³ JFF * =

8.8 Hz, ⁵ JFCH ₃ = 1.1 Hz. Ratio A: B = 1: 1.3. 35

IR: V (CC) 1669 cm " ¹ (thick), 1611 cm" ¹ (medium).

0 30009/015 2

ORIGINAL

'' 7

Example 7

50.8 g of CGF ₁₇ -CCCH ^) = CH-CH ₂ Cl (0.1 mol) as in Example 4, but reacted with a reaction time of 2 hours at 100 ⁰ C. 26.0 g of the compound C ₇ F ₁ C-CF = C (CH,) - CH = CH ₂ with a boiling point of 76 to 77 ° C./10 Torr (57.2 % yield) are obtained.

Analysis for ^C ₁₂ ^H 6 ^F 16 ^:

Calculated: C 31.74 H 1.33 F 66.93 Found: 31.7 1.4 66.7

19th

The F-NMR shows an isomer ratio of A: B = 1: IR: V (C = C) 1661 cm " ¹ (medium), 1611 cm" ¹ (weak).

Example 8

Analogously to Example 4, 67.6 g (0.25 mol) of C ₂ F ₅ -CH = CH-CH (CgH ₅ ) Cl are reacted with Zn / Cu. Working up is carried out in such a way that, after the reaction has ended, the solid fraction is centrifuged off and the liquid phase is distilled in vacuo.

41.0 g of the diene boiling at 92 ° C./10 Torr are obtained (75.9 % yield).
Analysis for C., .HgF,:

Calculated: C 61.12 H 3.73 F 35-15 Found: 61.2 3.8 35.0

¹ H-NMR: 7.20 ppm (5 H, aromatic), 6.89 to 5.68 ppm (3H, olefinic).
The main component

030009/0152

<■ ·: ORIGINAL INSPECTED

^{= Isomer}

^H b ^C 6 ^H 5

• χ

has the following coupling constants: JH F =

³ JHH. = 10.5 Hz, ³ JH, H = 15.0 Hz, ⁴ JHH ao D c ac

0.8 Hz.

¹⁹ F-NMRi isomer A: 56.4 ppm (1 F), -6.5 ppm (3 F); Isomer B: 51.2 ppm (t F), -11.2 ppm (3 F). Ratio A: B = 5.7: 1.

IR: "V (C = C) 1679 cm"" ¹ (very strong), 1624 cm" ¹ (weak)

Example 9

-1. 3 ₌ butadiene

This diene is obtained by reaction of 117.6 g

C ₆ F ₁₃ -CH = CH-CH (C ₆ H ₅₎ Cl (0.25 moles) with Zn / Cu according to Example 8, but obtained with a 2-hour reaction at 100 ⁰ C. Yield: 81.0 g (77.9%) of a colorless oil of boiling point 96 ^Q C / Q.2 Torr.

Analysis for C ₁ ^ HqF ₁₂ S

Calculated: C 43.29 H t.94 F 54.78
Found: 43.2 2.1 54.5

¹⁹ F-NMR: shows an isomer ratio A: B = 4: 1.

IR: ν (C = C) 1672 cm " ¹ (strong), 1623 cm" ¹ (weak).

03 ^ 009/0152

ORIGINAL INSPECTED

. ^ _ 2835450.

Manufacture of polymers

Example 10
Poly-JCF ₃ -CF = CH-CH = CH ₂ ]

A mixture of 5 g of i-fluoro-i-trifluoromethyl-i.3-butadiene and 0.05 g of azo-bis-isobutyronitrile is kept in a sealed ampoule at 85 ^° C. for 50 hours. This gives a product which ^{melts at 162 °} C. and thermally ^{decomposes from 250 °} C. and has elastomeric properties.

The ^ H-NMR spectrum in CD ₃ OH shows signals for olefinic protons (6.12 to 5.12 ppm) and saturated protons (2.97 to 2.27 ppm) in a ratio of 1: 1.

Example 11

Poly- [CF ₅ -CF =

A vial containing a mixture of the monomer with 1 part by wichts- # azo-bis-isobutyronitrile is first 10 hours at 80 ° C then _t a further 10 hours at 90 ⁰ C heated. A colorless, transparent and glass-hard polymer is obtained.

Thermal behavior: The polymer is at 80 ⁰ C glassy "turns slowly brown from 165" ⁰ C and begins to decompose recognizable at 220 ⁰ C .. The differential Theraoanalyse shows a number starting at 190 ⁰ C and above 225 ⁰ C rapidly progressive decomposition.

A sample purified by dissolving in benzene and precipitating with methanol has the following proton resonance spectrum (in C ₆ D ₆ ): 5.95 ppm (1 H); 3.28 ppm (1 H) i 2.88 pp «(1 H) and 2.00 pp» (CH ₃ ).

IR spectrum: y (C = C) 1670 cm "" ¹ , (weak).

GSO0Ö9 / QT52

ORIGINAL INSPECTED

The spectra show that the polymer goes through head Tail linkage of the monomer units is formed and essentially has the following structure:

-CH.

CF-

: (ch ₃ ) = ch-ch ₂

Example 12

Poly- [C ₇ F ₁₅ -CF = C (CH ₃ ) -CH = CH ₂ J

The monomer is polymerized analogously to Example 11. This gives a solid, colorless product which softens at 120 ⁰ C and decomposes 280-290 ⁰ C. The proton resonance spectrum of this product is identical to that of the product of Example 11.

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Claims (6)

Claims Hoe 78 / F 922 , 1. ii-Fluoro-i-perfluoroalkyl-i ^ -dienes of the formula R _f R ^{3 N} C = CR ¹ -CR ² = ^ (I), F ^ V wherein R _{f is} a perfluoroalkyl radical having 1 to 12 carbon atoms and Λ Ο " ³ J 4 R, R, R, R, which can be the same or different, for hydrogen, for an alkyl radical with 1 to 10 carbon atoms, for the cyclohexyl, phenyl, benzyl, naphthyl radical or represents an alkylphenyl or alkylnaphthyl radical with an alkyl chain of 1 to 5 carbon atoms. 2. Process for the preparation of 1-fluoro-1-perfluoroalkyl-1,3-serve according to claim 1, characterized. that a halogen alkene of the formula R - CF ₀ ^{-CR 1} = CR ² -CR ³ RX, 1 2 ^ 4 ¹ ^ where R _f , R, R, V / and R have the abovementioned meaning and X = Cl, Br or J, with at least the stoichiometrically calculated amount of a metallic halogen acceptor in the presence of a polar, aprotic solvent at temperatures from 40 to 150 ⁰ C is implemented. 3. The method according to claim 2, characterized in that an activated metal pair as the metallic halogen acceptor, consisting of zinc and a metal, which is more electropositive than zinc, is used. 4. The method according to claim 3, characterized in that the activated metal pair consists of zinc and copper. 5. The method according to claim 2 to 4, characterized in that the polar, aprotic solvent Dimethy! Formamide, Dimethyl sulfoxide, a dialkyl ether or Mixtures of these solvents are used. 030009/0152 ORIGINAL INSPECTED -S- 28354? = 6. Use of the 1-fluoro-i-perfluoroalkyl-i.3-dienes for the production of polymers « 030009/0152 ORIGINAL