DE1668554C - Process for the production of fluoroolefins - Google Patents

Description

A process for the preparation of fluorine- necessary catalyst is in the liquid medium

olefins düich reaction of alkynes with 2 to distributed. In such a liquid reaction medium

10 carbon atoms, phenylacetylene or mono- can hydrogen fluoride and "acetylene (or a

chloroacetylene with hydrogen fluoride in the presence of a similar alkyne) in essentially equimolecular proportions

Mercury compound found as a catalyst that has 5 (stoichiometric) ratios (usually in

is characterized in that the reaction form of gases) are introduced, namely before

in the liquid medium with the equimolar amount, preferably below the liquid level.

Hydrogen fluoride and in the presence of an organic The temperatures can be used for the implementation

Fluoride · or an alkali fluoride. of the procedure can be chosen differently

Vinyl fluoride can be known by vapor phase io but preferably between -15 and +90 ⁰ C. Although

hydrofluorination of acetylene are produced, usually at or near atmospheric

where one will usually work using a suitable pressure (up to 5 atmospheres absolute),

Catalysts works. Suitable catalysts, it is also possible, sub-atmospheric or higher

are mentioned in the relevant literature, are to be used as the stated pressures if appropriate

Mercury compounds. In general, the 15 Safety Precautions to be Taken When Acety-

Vapor phase hydrofluorination, however, has the disadvantage of len or other alkynes that are sensitive to pressure

on that significant amounts of a by-product are to be handled. Among the usual

z. B. ethylidene fluoride are formed. The prevailing pressure and temperature conditions

Driving is further disadvantaged by the fact that vinyl fluoride is gaseous.

Catalysts only have a limited service life. The reaction should preferably be carried out in this way

wise, d. i.e., the catalyst activity decreases as the end product, e.g. B. the vinyl fluoride,

Processed in a relatively short time. leaves the reaction mixture as a gas. The conditions

The reaction medium consists of organic genes, especially the residence time of the reaction fluorides. Hydrofluorides of amines, especially participants, must be selected so that secondary and tertiary amines, including tri- »5 j _m substantially complete hydrofluorination of the ethylamine, tri-n-heptylamine and triisopropylamine, is achieved. This means that they are particularly useful. Sufficient amounts of hydrogen fluoride are particularly suitable (about 1 mole are also liquid media that contain hydrofluorides of aro- per mole of alkyne + the amount of hydrogen fluoride, the matic tertiary amines such as dimethylaniline form fluorine escaping from the reaction medium. Other tertiary anilines including N, N -Di- 30 must replace hydrogen) and that alkyl anilines such as N-ethyl-N-methylaniline are also useful for a sufficiently large amount of liquid reaction for the purposes of the invention. Also medium is available. Temperature and pressure primary amines such as aniline can be used. conditions must be chosen so that a heterocyclic amine, especially heterocyclic volatilization of the liquid medium to a mini-compound containing a ring nitrogen atom, is limited to 35 mum, without the development such as pyridine, piperidine, piperazine, Ciiinuüri, methyl is hindered by vinyl fluoride from the medium, morpholine, triethylenediamine, quinuclidine, isochino- The liquid medium with the fluoride must be chosen so lin, quinaldine as well as <x- and /? - picoline are combined that at sufficiently high temperatures also with hydrogen fluoride below Formation can be carried out in a suitable manner without the formation of any noteworthy fluoride. Quinoline hydrofluoride or - how the 4 ° volatilization of the medium occurs.
Compound is sometimes called - quinolinium-. 11
fluoride is an organic fluoride that is used for the purposes of Example 1
of the invention is particularly suitable. The reaction vessel is arranged vertically

According to a preferred embodiment, tube made of polytetrafluoroethylene, commercially under the

Quinoline hydrofluoride with 3 to 9 mol (preferably 45 called »Teflon« available, with an inner

about 7 moles) hydrogen fluoride per mole of the compound diameter 6.35 cm, height 61 cm

combined; into the particularly effective and approximate volume of 1700 cm ^{3 obtained in this way} .

Acetylene is introduced into the reaction medium; Vinyl- The reaction vessel is curved with a U-shape

fluoride can be withdrawn as a reaction product. Heating coil made of copper, a cylindrical gas

Another useful reaction medium consists of an inlet tube (1.27 cm in outer diameter and

for example from a product in which 3 to 4.14 cm in length), removal device at the bottom

7, preferably about 5 moles of hydrogen fluoride per end, catalyst feed tube (0.8 cm outer

Moles of dimethylaniline are bound. Diameter; the tube extends to two inches

Alkali fluorides, such as sodium, lithium, potassium below the normal liquid level in the reaction imd Ammonium fluoride, are also useful. 55 vessel) and a gas pipe. Leaves In the case of these inorganic salts, the liquid one consists of the U-shaped copper snake during Rcaktionsmcdium apparently zirdes from a solution of charging the reaction vessel with ice water Salt in hydrogen fluoride, d. that is, the fluoro water, this serves as a coolant at this point in time serves as a solvent. device so that hydrogen fluoride condenses

When the hydrofluorination is carried out, it becomes ⁵ °. During the reaction, under thermo-

a suitable liquid reaction medium, which static conditions hot water through the

which contains fluoride, first produced, and indeed sent copper snake so that it

if the fluoride is either generated in situ or the medium is heated.

by inserting the previously formed salt into the reactor.

tion vessel transferred. For example, you can put a 65 interconnected steel cooler and then through a

Prepare a liquid mixture by passing 2 to 9 mol of the Druckentspar.nungssystem to the pressure

Hydrogen fluoride per mole of quinoline, dimethylaniline of the exiting gases to atmospheric pressure

or a similar organic base is used. The bc- relax (if at superatmospheric pressures

3 4

has been worked). The atmospheric pressure materials in the ratio of 1.10 moles of HF

Bring gases are then fed in two polyethylene per mole of acetylene. After 5 hours

Washers washed, each of which was 25 weight operating time, the vinyl fluoride content in the deductible

percent aqueous KOH solution (to remove the gas flow to about 55%; to this

from HF). The HF-free gas was released by 5 time point, which was converted by addition

a wet measuring device, dryer and removal of 0.005 mol of catalyst to almost 100%

Caution raised for gas-liquid chromatography. During the experiment contained the liquid

and passed a rotameter and finally through a medium \ on 7 (at the beginning) to 6 (at the end) moles of HF

Extractor hood extracted. _per MpI quinoline.

Using the above-described io

Equipment and the work described above- B eis ρ ie 1 4
Vinyl fluoride was wisely made from acetylene and hydrogen fluoride. 2.5 mol (322 g) quinoline The equipment and procedure are used in the nitrogen-filled reaction according to Example 1, but the pressure vessel is filled while ice water is conveyed through the U-15 of 0.84 kg / cm ² . In the course of a 10-hour vermige copper snake, until the quinoline was found, 319 kg of vinyl fluoride per kilogram were assumed to have a temperature of about 5 to 10 ° C. Diphenyl mercury catalyst (mercury base). The gas inlet was then used, with HF and acetylene being introduced into the quinoline in the molar ratio of tube HF, up to about 17.5 mol of 1.28: 1. Almost during the (350.2 g) HF were present, what a total of the whole experiment was the vinyl fluoride content in the settling of the liquid of about 7 moles of HF per mole of withdrawing gas after washing corresponds to a quinoline only. initial catalyst addition of 0.005 mol

The catalyst was in the form of a solution of nearly \ 00%. During the experiment, the HF

Diphenylmercury fed into quinoline. The Kon- quinoline ratio in the liquid medium between

The concentration of diphenylmercury was such that 25 6 and 7: 1.

5 cm ^{3 of} the solution 0.8845 g of diphenylmercury (ent- _R ...., -

i.e. 0.5 g of mercury). Example ο

It was at atmospheric pressure and a Rea- The procedure according to Example 4 was again-

tion temperature of 70 ° C worked. It was fetched, but it was worked at 50 ° C, and it was

at least about 1 mol (occasionally a little more, e.g. 30 equimolecular amounts of HF and acetylene added

1.1 mol) of hydrogen fluoride and 1 mol of acetylene, so that 199 kg of vinyl fluoride per kilogram

guided. The catalyst solution was periodically generated catalyst (mercury base),
added; the procedure was a total of 36 hours

operated. The amount of vinyl fluoride in the exiting example 6

Gas flow increased depending on the age of the catalytic converter

starting from 100 percent by volume, using the device and the working

the higher values immediately after addition, according to Example 1, was determined in the course of a 30-hour

of the catalyst (5 cm ⁸ or about 0.0025 mol of diene attempted vinyl fluoride in an average

phenylmercury) observed during the experiment borrowed amount of 440 kg per kilogram of catalyst.

became. The catalyst solution was generated at intervals of 40 sator (mercury basis). It was with one

added when observation indicated that the pressure of 0.84 kg / cm * worked. The liquid me-

The vinyl fluoride content in the exiting gas was about dium in the reactor at the beginning of the experiment

Had decreased by 50 or 60 percent by volume. Made by adding 17.5 moles of HF and 2.5 moles

At the end of the operation, the molar ratio of dimethylaniline introduced changed; during the experiment

from HF to quinoline in the liquid reaction between 1.1 and 1.33 moles of HF per mole of acetylene

medium between 5.5 and 7: 1. fed.

The higher HF-quinoline ratios in Example 7
Fluid then showed up when a little more than

1 mole of HF per mole of acetylene in the reactor. Example 6 was repeated once more, however

was conducted. 5 ° with a medium which initially contains 21 moles of HF

_n ". “·, Τ and 3 moles of dimethylaniline; it was vinyl

fluoride generated.

Using the equipment (without gas- Example 8
inlet pipe) and using the procedure of Example 1, the system was repeated one more time in Example 7, operating at a pressure of 0.42 kg / cm ^{2 for} 10 hours. however, mercury oxide was used as a catalyst. Diphenylmercury was only used once to begin with; during a 55 hour run were fed as a catalyst. In the specified time, 683 kg of vinyl fluoride per kilogram of catalyst, about 227 kg of vinyl fluoride per kilogram (mercury basis) were produced.
Mercury scores at conversions of 60 to 60

80%. The HF-quinoline ratio fell during Example 9
Attempt from 7: 1 to 6: 1.

The device and the mode of operation according to

Example 3 Example 1 were used in the course of a

With the equipment and the procedure according to 65 8-hour experiment methylacetylene to hydrofluoric

For example, 264 kg of vinyl fluoride per kilo and 2-fluoropropene were produced. The attempt grams of catalyst (mercury base) in the course was run at 70 ° C; there were both

of a 12-month insurance, whereby the Au «; - diphenylmercury and mercury oxide (HgO)

introduced as catalysts in the liquid medium. The ratio of HF to diniethylaniline in the liquid medium was 6: 1. The average conversion was about 61%.

Example 10

As in Example 9 methylacetylene was hydrofluoriert, but C has now worked at 85 ^0th There was a slightly higher conversion (about 77%) to 2-fluoropropene.

Examples 9 and 10 prove that the inventive method for hydrofluorination of other acetylenically unsaturated compounds, d. H. Alkynes, can be used as acetylene. The hydrofluorination of the acerylenic bond is generally carried out according to Markownikoff's Usually (methylacetylene is mainly converted to 2-fluoropropene) · It is therefore generally possible lower alkynes and substituted acetylenes such as phenylacetylene and monochloroacetylene as well other compounds with 3 to 10 carbon atoms easily hydrofluorinated.

Example 11

A reaction vessel made of chlorotrifluorethylene was used 13 g (0.1 mol) of quinoline and 1 g of the catalyst mentioned in the table below were used together with the specified molar amount Hydrogen fluoride supplied; the latter was in

ίο the mixture of quinoline and catalyst initiated at the temperature given in the table. The acetylene was then ^{added at 70 °} C., and a start was made at a rate of 0.065 mol per hour. The gas flowing out of the reaction vessel was washed with water, mixed with carbon dioxide at a rate of 0.015 mol per hour and analyzed by gas chromatography.
In the following Table I are the various

ao reaction conditions and the results of the experiments are compiled.

Table I.

MoIHF catalyst temperature Mole percent in the withdrawing stream C ₁ H, C ₁ H ₃ F ⁰ C CO, 7.8 71.8 0.6 Diphenyl mercury 70 20.4 2.9 77.4 0.9 Diphenyl mercury 30th 19.7 2.5 77.7 0.9 Diphenyl mercury 30th 19.8 13.7 64.0 0.9 , - diphenylmercury 0 22.3 5.9 74.9 0.9 Mercury (I) acetate 30th 19.2 1.9 77.2 0.9 Mercury (II) oxide 30th 20.4

The above data show that the hydrofluorination ^{can be carried out both at 0 °} C. and at 70 ^° C., with different ratios of hydrogen fluoride and quinoline.

Example 12

Tables are shown (with the exception that the hydrogen fluoride at room temperature, ie about working as indicated in Example 11 and 40 25 ° C, and not at a temperature of 70 ⁰ C applies the conditions which are given in the following) the following results are obtained:

Table II

MoIHF catalyst temperature CO, Mole percent products C.H.F ⁰ C 20.0 8.5 0.9 Diphenyl mercury 0 19.4 76.6 0.9 Mercury (I) trifluoroacetate 30th 32.4 58.7 0.9 Diphenyl mercury -7 19.2 2.5 0.4 Diphenyl mercury 30th 19.0 4.9 0.4 Diphenyl mercury 70 22.6 70.5 1.5 Diphenyl mercury 30th C ₁ H, I 71.5 4.0 8.9 78.3 76.1 5.7

Example 13

The apparatus described in Example 11 is used, but a magnetic stirring bar coated with polytetrafluoroethylene is used. Acetylene was fed at a rate of 0.065 mole per hour while hydrogen fluoride was fed into the liquid mixture at a rate of 0.1 mole per hour. The latter consisted of 1 g of diphenylmercury, 13 g of quinoline and 0.3 mol of hydrogen fluoride. The composition of the reaction gases after 24 hours of operation was 18.9% CO ₂ , 26.7% C ₂ H ₂ and 54.5% vinyl fluoride (on a molar basis).

Example 14

The apparatus was used and the procedure followed according to Example 13. 1 g of diphenylmercury, 0.1 mol of the inorganic given in Table III Fluoride and 0.9 moles of hydrogen fluoride were introduced into the reactor. The results are also compiled in table 111:

Table III Fluoride, mole

0.1 NH ₄ F
0.1 NaF.

Mole percent products
CO, I CH ₂ I QH ₁₁ F

19.9
19.9

4.0

21.0

68.0
59.1

Example 15

The experimental arrangement and procedure corresponded to that of Example 11, but 0.1 mol of benzonitrile was used instead of quinoline. The gas produced was (on a molar basis) of 20.3 ° / ₀ CO _2, 16.4% C _g H, and 63.3% of vinyl fluoride.

. B e i s ρ i e 1 16

The procedure indicated in Example 11 was followed, with the exception that a solvent indicated in Table IV was used instead of quinoline. 1 g of diphenylmercury was added as a catalyst; the temperature was 30 ^° C. The following results were achieved:

Table IV

Solvent (MoI) HFMoI

Mole percent product CO ₁ C ₁ H,

C.H.F

0.10 diethylene glycol dimethyl ether

0.05 di-n-butyl adipate *

0.05 tri-n-heptylamine *

0.10 aniline *

0.20 diallyl phthalate **

0.45

22.0

22.7

40.9 34.7 61.0 38.6 28.7 71.3 3.0 96.7 43.9 33.4

* Does not contain CO ₁ .
* · At 60 ⁰ C, not at 30 ⁰ C.

When using diethylene glycol dimethyl ether small traces of Äthylidendifluoiid were also as a solvent, about 2.4 mol percent of ethyl was observed in the experiments carried out with di-n-butyllidene difluoride detected in the product gas stream. 95 adipat and aniline were carried out.

Claims (1)

Claim: Process for the production of fluoroolefins by reacting alkynes with 2 to 10 carbon atoms, Phenylacetylene or monochloroacetylene with hydrogen fluoride in the presence of a Mercury compound as a catalyst, characterized in that the Reaction in the liquid medium with the equimolar amount of hydrogen fluoride and in the presence an organic fluoride or an alkali fluoride. 209632/266