DE1283228B - Process for the preparation of vinyl esters - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

German class:

Number:
File number:
Registration date:
Display day:

C07c

BOIj

12 ο -19/03

12 g-11/00

P 12 83 228.9-42 (S 103040)

April 5, 1966

November 21, 1968

CO CO (M

in US Pat. No. 2,066,075, R e ρ ρ e described the vinylation of carboxylic acid with at least 5 carbon atoms by reaction in the liquid phase with acetylene in the presence of a Carboxylic acid salt of zinc or cadmium.

The zinc salt of the acid to be vinylated can also be used as a catalyst in the reaction in the liquid phase used itself (German Patent 588 352 and USA Patent 2 228 365) and as a carboxylic acid a those with a tertiary or quaternary carbon atom in the α position are used (British patent specification 992 648).

Processes for vinylation in the gas phase have also been proposed, e.g. B. in the French Patent specification 1252 416. In U.S. Patent 2,381,338 it is even mentioned that the Pivalic acid can only vinylate in the gas phase because acetylene cannot with the acid in the liquid phase react. Nevertheless, vinylation in the liquid phase has advantages, e.g. B. the opportunity for better Control of the reaction temperature, a higher reaction rate, a better selectivity and consequently fewer by-products.

The invention relates to a process for the preparation of vinyl esters of carboxylic acids with a tertiary or quaternary carbon atom by reacting this acid with acetylene in liquid Phase at elevated temperature and in the presence of a zinc salt of a carboxylic acid as a catalyst and is characterized in that the reaction is carried out in the presence of a catalyst, which contains a metal-containing Lewis acid as a cocatalyst.

According to the definition (cf. e.g. O 1 a h, »Friedel-Crafts and related reactions «, Intersc. Publ. 1963, Vol. I, p. 173 ff.) Lewis acids are those compounds which can accept a pair of electrons to form a covalent bond. According to the invention Process for the production of vinyl esters

Applicant:

Shell

International Research Maatschappij N.V.,

The hague

Representative:

Dr.-Ing. Franz Wuesthoff,
Dipl.-Ing. Gerhard Puls,
and Dipl.-Chem. Dr. rer. nat.
Eckehart Baron von Pechmann,
Patent Attorneys, 8000 Munich

Named as inventor:

Hans Jürgen Arpe, 5201 Kohlkaul

should those Lewis acids be used that have a metal atom as the electron pair-accepting central atom, including boron. In this context, boron is understood as a metal. Examples such suitable Lewis acids are the halides, especially the chlorides of lithium, beryllium, Zinc, palladium, boron, aluminum, gallium, didymium, cerium, iron, chromium, zirconium and uranium. As is well known Commercially available didymium consists mostly of a mixture of rare earths made of lanthanum and neodymium as well as small amounts of praseodymium and samarium. Such a material is with the following composition

La ₂ O ₃ = 45%; Nd ₂ O ₃ = 38%; PrJ ₁₁ = 11%; SmO ₃ = 4%

commercially available and mostly comes from the processing of monazite sand on cerium. In the case of iron, aluminum or didymium, the sulfates or phosphates can also be used instead of the halides. Good results have been obtained in particular with aluminum chloride and didymium chloride (DyCl ₈ ).

It has been observed that the use of cocatalysts containing water of crystallization, such as DyCl ₃ · 6 H ₂ O and AlCl 3 · 6 H ₂ O, has advantages, as can be seen from a comparison of Examples 8 and 9. The same advantages can be achieved if small amounts of water are added continuously or discontinuously to the reaction mixture, e.g. B. in the form of an acetylene stream laden with steam.

A zinc salt of the carboxylic acid which is vinylated according to the invention is preferably used as the catalyst shall be. However, one can also start from salts of other acids. Only then it slowly becomes Anion of the other acid exchanged for the anion of the acid to be vinylated. These salts can can be easily produced by e.g. B. zinc oxide,

809 638/1721

3 4

Polymerize zinc hydroxide or zinc carbonate with the acid in saturated compounds or, more commonly, copoly Way. You can merize the salt beforehand. Draw the (co) polymers obtained or it emerges from the reaction mixture itself due to its good chemical resistance. she leave. are used, among other things, as thickening

The liquid phase in which the vinylation is carried out, emulsifiers, dispersants, as a compo should be, z. B. by the melt of the component in alkyd and epoxy resins and as a viscosity zinc carboxylate be formed themselves. Useful improver in lubricating oils.

however, a high-boiling, i.e. H. one above is preferably used in the vinylation

250 ⁰ C, preferably above 300 ⁰ C, boiling Lö- atmospheric pressure. With the use of spesmittel used in which the zinc salt and the io cial precautions to reduce the explo-cocatalyst are dissolved. Without adding the risk of corrosion, it is also possible to use higher pressures; the catalyst is often the zinc salt in the solvent, possibly also under reduced pressure. The molar is not soluble. The cocatalyst ratio of acetylene to carboxylic acid cannot be dissolved in the allsator in the absence of the tin salt either. The average is between 1: 1 and 30: 1, and in general catalyst concentrations between 2: 1 and 10: 1 are preferably used.

between 0.5 and 20, in particular between 5 and The reaction temperature is between 200 and

15 percent by weight zinc salt, based on solution 300 ° C, preferably between 225 and 290 ° C. at middle. The cocatalyst concentration is expediently lower temperatures there is a risk that moderately between 5 and 150, in particular the catalyst complex precipitates and that the conversion between 10 and 80 mole percent, based on zinc-20 decreases.

carboxylate. The space velocity at which the acid passes through

The solvent should be carried out under the reaction conditions, the liquid phase is generally conditions should be as inert as possible. Suitable are e.g. B. between 20 and 300, preferably between 50 and Hydrocarbons such as paraffins and cycloparaffins 200 grams of acid per kilogram of liquid phase per having at least 16 carbon atoms. As an advantageous 25 hours. Unproven under the given reaction conditions Petroleum fragments boiling above 300 ° C is the concentration of the acid in the liquid functions, such as desulphurized gas oil fractions, spindle phase only slightly and is z. B. below 5 weight oils, medicinal oils, which under the designation "shell percent, mostly still below 3 to 1 weight ondine" 33 are commercially available and a percent.

mixes paraffinic naphthenic oil with a 30 The vinyl ester and the unreacted acid boiling range are from 400 to 470 ° C. Others vaporize from the liquid phase and can escape from the Suitable solvents are the anhydrides removed from the reaction vessel and condensed, branched acids, which are difficult to hydrolyze and expediently one used above the Boiling sufficiently high, polyethylene and polypropylene liquid phase introduced inert gas stream, z. B. glycol or polyphenyl ether. ■ 35 nitrogen. Preferably, the invention

It has further been found that the use of vinylation in the absence of oxygen through high-boiling Ester oils thereby offers advantages that led.

the service life of the catalyst solution is considerable. The continuous or discontinuous addition

can be extended. Suitable esters are e.g. B. of smaller amounts of hydrochloric acid during the invention-Dilaurylsebacinsäureester, chlorinated polyphenyls or 40 proper, continuous vinylation has Laurylpivalinsäureester. Very favorable results have been shown to be advantageous because the life of the catalyst obtained with esters of geminal polymethanol catalysts is thereby extended. Preferably compounds such as trimethylolpropane esters of are added to the reaction mixture per hour of branched carboxylic acids, in particular with the ester continuously ¹ J ₂ to 20 mol HCl per mol in the mixture of 1,1-dimethylolcyclohexane and the catalyst present to.

from diisobutylene. Under certain circumstances you can still extend the service life

The catalyst solution is preferably further extended beforehand by adding it during the reaction activated by having them at temperatures between further smaller amounts - z. B. 5 to 20 mol-250 and 300 ° C for some time, e.g. V2 to 2 hours, percent, based on zinc carboxylate - of co-together heated with the reaction components. 50 catalyst.

The process according to the invention can be applied to the reaction according to the invention in particular

Use carboxylic acids that have a tertiary or suitable for the continuous vinylation of carquaternaries Carbon atom in position to the carboxylic acids. If necessary, you can see the reaction own oxyl group, preferably carry out on monocarbon but also rudimentary, acids with at least 5 carbon atoms, such as iso-55

butyric acid and pivalic acid. Such acids can be examples

obtained in a simple manner by the Koch synthesis

be, d. H. by reacting olefins such as iso- The glass reaction vessel that is commercially available under

butylene, diisobutylene, cracked olefins with 6 to 8 or the designation "Pyrex glass" is available, 8 to 10 or 12 to 14 carbon atoms, propylene-60 was electrically heated. The reactants - pivatrimer or tetramer, with CO / H ₂ O in the presence of iic acid and acetylene - were thrown through the axis of an acidic catalyst. The invention is guided by a "vibromixer" into the reaction mixture, a particular advantage for the vinylation of Koch. The pressure in the reaction vessel was about acids with 5 to 9 carbon atoms, which are 1.1 at. The gases introduced were previously washed in an oxygen-free pyrogallol solution which is only poorly or excessively alkaline according to the known method and not vinylated at all in the liquid phase permit. and then dried. A stream of nitrogen The vinyl esters obtainable from these α-branched acids were constantly passed over the reaction mixture

converted acid. These were collected in cold traps (0 and -60 ⁰ C); the composition of the condensate and the exhaust gases was determined by gas chromatography. The condensate consisted mainly of pivalic acid and vinyl pivalate. The ester was separated off by distillation: Κρ. _7β0 = 112 ⁰ C; n% ° 1.4058. It was stabilized with 0.1 percent by weight hydroquinone.

The liquid catalyst phase was prepared in 100 ml of an oil commercially available under the name "Shell Ondina" 33, which is a high-boiling paraffinic and cycloparaffinic hydrocarbon mixture, by adding zinc pivalate and the cocatalyst. The mixture was heated for 15 minutes 25O ⁰ C. Any water of hydration present was removed by passing nitrogen over it. The catalyst solution was activated by passing the reactants (pivalic acid, acetylene and optionally hydrochloric acid) ^{through at 270 °} C. for 1 hour. The reaction temperature was then set. Zinc pivalate was made from zinc hydroxide and a 50% excess of pivalic acid in ethanol. The zinc pivalate crystallized out on cooling.

The catalyst solution used in Examples 1 to 10 contained 14.35 percent by weight of zinc pivalate in "Shell Ondina" 33 and 10 mol percent (on Zn pivalate) of cocatalyst. Space velocity: 72 g Pivalic acid per kilogram of catalyst solution per hour. Molar ratio of acetylene to pivalic acid = 3.79. The results can be seen from the following table:

at
game 5 1 Cocatalyst Tempe
rature Acetylene-
Sales*) yield
of vinyl
pivalate **) 2 (Mol (Mol 3 ( ⁰ C) percent) percent) 10 4 LiCl 280 93 51 5 ZnCl ₂ 280 46 46 6th ZnCl ₂ 260 54 52 7th PdCl ₂ 280 139 86 8th PdCl ₂ 260 82 53 15 9 CrCl ₃ 280 70 56 10 FeCl ₃ 280 121 76 AlCl ₃ 260 79 70 AlCl ₃ · 6 H ₂ O 260 100 90 DiCl ₃ • 6 H ₂ O 260 106 73

*) Based on the amount of pivalic acid imported. If the conversion was more than 100%, polyacetylene was probably formed.
**) Based on the pivalic acid used.

In comparative tests it was found:

a) showed in the absence of LiCl Zinkpivalat not yet ZnCl ₂ up to 300 ⁰ C Vinylierungsaktivität;

b) it is possible to dissolve about 10% zinc pivalate in the oil used after adding pivalic acid the zinc pivalate largely precipitates and is therefore no longer catalytically active. In general only has zinc pivalate as a catalyst for the vinylation of pivalic acid without a cocatalyst very little activity;

c) neither didympivalate nor lithium pivalate are catalytically active per se.

In further experiments with LiCl as cocatalyst, the above reaction conditions were varied, as can be seen from the following table:

Zn pivalate LiCl space Molar ratio temperature sales Yield to example (Weight (Mol speed C ₂ H ₂ / pivaline ( ⁰ C) QH ₂ Vinyl pivalate percent) percent) (g / kg / hour) acid 300 (Mole percent) (Mole percent) 11 10.25 125 68 3.3 280 99 57.4 12th 10.25 125 66 3.2 265 88 67.0 13th 10.25 125 62 3.3 265-270 49 38.0 14th 14.35 126 65 3.2 280 56 49.3 15th 14.35 54.6 52 5.2 280 121 55.7 16 14.35 32.8 55 4.9 280 118 55.5 17th 14.35 10.9 53 5.1 280 75 48.0 18th 14.35 10.0 72 3.8 280 93 51.4 19th 14.35 4.2 68 4.0 48 36.0

In further experiments with DyCl ₃ as cocatalyst, the above reaction conditions were also varied. A space velocity of 70 g pivalin

The results can be seen in the table:

acid per kilogram of catalyst solution per hour and a molar ratio of acetylene to pivalic acid of 3.8 were used.

example Zinc pivalate
Weight percent DyCl ₃ · _{7.5H 2} O temperature Pivalic acid
sales selectivity
Mole percent based in "Ondina" (Mole percent) ( ⁰ C) (Mole percent) on vinyl pivalate 20th 14.35 10 250 54.7 98 21 14.35 20th 250 66.9 97.4 22nd 14.35 30th 250 71.9 96.8 23 7.18 10 240 40.7 99 24 7.18 20th 240 51.3 98.9 25th 7.26 18.7 230 26.7 100 26th 7.26 27.9 230 43.3 98 27 7.26 37.3 230 27.7 88.3 28 7.26 46.6 230 20.7 73.2

If CeCl ₃ · aq was used instead of DyCl ₃ under the same conditions as in Example 26, a conversion of 43.7 mol percent of pivalic acid was obtained with a selectivity for vinyl pivalate of 99.5 mol percent (Example 29).

To determine the optimal space velocity, 61 / hour. of acetylene and various amounts of pivalic acid at 230 ° C through 100 ml of "Ondina oil" containing 7.26 percent by weight of zinc pivalate (based on "Ondina") and 27.9 mol percent of DyCl ₉ (based on zinc pivalate). The results can be seen from the following table:

Space velocity Pivalic acid conversion ^ pipicfivifäf productivity example (g pivalic acid / OvivJV Lx VXLdL
(Vinyl pivalate) g vinyl pivalate / kg catalyst solution (Mole percent) kg catalyst solution per hour) 67.1 (Mole percent) per hour 30th 34 43.3 99 28.4 31 68 27.3 98 36.2 32 105 11.7 100 35.9 33 171 99 24.9

That the cocatalytic activity does not depend on halogen - through 100 ml »Ondina-Ök, the 7.26 percent by weight

nide is limited, the following experiments assume zinc pivalate and 30 atomic percent (based on zinc

emerged. Acetylene (61 / hour) and pivaline ao pivalate) of a didymium salt were contained, passed the

acid (70 to 80 g / kg catalyst solution per hour) results are shown in the following table:

example Cocatalyst temperature
CQ Pivalic acid conversion
(Mole percent) selectivity
(Vinyl pivalate)
(Mole percent) 34
35 Tue ₂ (SOY ₈
DiPO ₄ 270
270 23
13th 100
100

The life of the catalyst solution can be extended by adding hydrochloric acid during the reaction, as can be seen from the examples below. Reaction conditions: 7.26 percent by weight zinc pivalate and 30 mol percent DyCl ₃ (on

Zn pivalate) in 100 ml "Ondina oil"; 61 acetylene each Hour; Reaction temperature 250 ° C; Selectivity greater than 95 mole percent. HCl gas became continuous added as indicated in the table:

Space velocity HCl lifespan Vinyl pivalate exploitation on average maximum all in all example (g / kg catalyst solution per hour) of the catalyst *) Mole percent Mole percent G Pivalic acid 0.02 hours 60.5 70 108 36 67 0.05 22.5 56.8 64.4 191 37 87 0.11 34.0 57.6 74.0 256 38 77 0.21 48.5 63.0 76.4 240 39 69 46.5 54.0 70 210 40 76 40.5

*) The life of the catalyst solution is defined as the time in which the yield of vinyl pivalate has reached a value drops by 25 mole percent.

The use of high-boiling esters as solvents also has a beneficial effect on the life of the catalyst solution and the overall yield of vinyl pivalate. This goes out of the The following examples show, in which the same reaction conditions as in Examples 36 to 40 were used. HCl was added continuously in an amount of 0.05 g / kg of catalyst solution per hour

returned. Ester A was obtained by esterification of the hydroxypivalic acid, on the one hand with Lauryl alcohol, on the other hand with "Versatic 9 acid", a "cooking acid" made from diisobutylene. Ester B consisted of from lauryl pivalate, ester C was a diester of 1,1-cyclohexanedimethanol and "Versatic-9-acid". the The results can be seen in the following table:

solvent Space velocity T? duration of the deal Yield of vinyl pivalate total example (g pivalic acid / kg cataly JL \ .w & Ak vJLV / A IO Ud UwJL on average S. Cetane solution per hour) (Hours) Mole percent 148 41 Ester A 87 27 49.3 342 42 Ester B 95 52 60.7 388 43 Ester C 84 ι 70 56.0 762 44 Glycerol tripivalin 76 155.5 54.8 44a acid ester 220 88 41 51.6

ίο

While the preceding examples related to the vinylation of pivalic acid, the following examples show that the present invention can also be used advantageously in the vinylation of other acids. In these experiments 80 to g "Versatic 9 acid" were vinylated per kg of catalyst solution similar to the preceding examples per hour with 6 1 acetylene / hour at 250 ⁰ C. The catalyst solution consisted of 100 ml of "Ondina 33-01" which contained 8.85 g of the zinc salt of the "Versatic 9 acid" and various cocatalysts (see table). "Versatic-9 acid" is a "cooking acid" made from diisobutylene.

example Cocatalyst Mole percent Reaction time
(Hours) Vinyl ester
Yield in the end
(Mole percent) 45 FeCl ₃ 30th 10 86 46 FeCl ₃ 30th 20.5 88 48 ZnCl ₂ 30th 10 83 49 DiCl ₃ aq 15th 10 69 50 DiCl ₃ aq 30th 10 63 51 LiCl 30th 10 63 52 Tue ₂ (SO ₄ ) ₃ 30th 10 52 - 10 21 - - - 26.5 21

Claims (1)

Claim: Process for the preparation of vinyl esters of carboxylic acids with a tertiary and quaternary «-Carbon atom by reacting this acid with acetylene in the liquid phase at increased Temperature and in the presence of a zinc salt of a carboxylic acid as a catalyst, thereby characterized in that the reaction is carried out in the presence of a catalyst which contains a metal-containing Lewis acid as a cocatalyst. Considered publications:
German Patent No. 588 352;
German Auslegeschrift No. 1 237 557;
U.S. Patent No. 2,228,365;
British Patent No. 998,648.