DE1943784A1 - Process for splitting off water from beta-oxycarboxylic acids or for splitting off hydrogen chloride from beta-chlorocarboxylic acids - Google Patents

Description

DR. ELISABETH JUNG. DR. VOLKER VOSSIUS, DIPL.-ING. GERHARD COLDEWEY TELEPHONE 340067. TELEGRAM ADDRESS: INVENT / MDNCHEN

TELEX 5 29 686

. Aug 1969

P 1690 (Pi / J / Jcä)

SHELL IBTEEHATIONALE RESEARCH HAATSCHAPPIJ NV ₀ , The Hague, The Netherlands

"Process for splitting off water from ß-oxycarboxylic acids or for splitting off hydrogen chloride from ß-chlorocarboxylic acids"

Priority: 30 August 1968, Great Britain, No. 41 520/68

The invention relates to a method for splitting off water ß-oxycarboxylic acids or toc elimination of hydrogen chloride ß-chlorocarboxylic acids; each of which is unsubstituted Carboxylic acids of the general formula I

R ³ - C - COOH (I)

τ ρ " ³ p
derive, - in which R% H and H are identical or different and alkyl

1 2

They have 1 to 4 carbon atoms are _0. The radicals R and R are preferably methyl groups, the radical P is an ethyl or methyl group., If, all three radicals are methyl groups are _p so the unsubstituted otric acid is pivalic acid, and the from the early derived ^ 'ilatituierten carboxylic acids, dit; a " ¹ 3 output"? v ·? fbindungen böi-i / experienced de ;? invention di ^ uen. ^ onneu, are Ox'- · - ■■■

009810 / ϊ 7L "p

BAO

Chlorpivallnsäur® ₉

There are known methods, the aforementioned. Type "in which H ₂ O aue fi-oxycarboxylic acids or HCl is split off from ß-chlorocarboxylic acids = In general, lactones and / or monolefinically unsaturated aliphatic carboxylic acids are formed from the rest of the molecules of the acids used as starting compounds"

The object of the invention is to provide a method for splitting off HgO from ß ~ oxycarboxylic acids or from HCl from ß-chloroic acids make available au, in which new catalysts are used.

The invention thus relates to a method for splitting off water from ß-oxycarboxylic acids or from HCl from B-chlorocarboxylic acids, the eich of non-substituted carboxylic acids of the general formula I.

H ¹
R ² - C - CCOH (I)

12 3
derive, in which R , R and H are identical or different and alkyl radicals with 1 to 4 carbon atoms, which is characterized in that the starting compounds in the vapor phase at a temperature above 100 ° C, but below $ enex temperature, at which the starting compounds and / or the washing products begin to decompose, not bringing them into contact with a solid catalyst, which consists of at least one nlchtbaeieohea? Hetallsalsi is coated by aifidesteae of such an inorganic acid derived from asn salt fisssls & ua ums. Äuegangs ^ e -: - fo

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fertilize HgO or HCl which are split off during the non-decomposition is (are) not released _o

The Reaktionetemperatur should generally be at most 500 C ο temperatures of 150 to 45O ⁰ C are very zweckmäesig usually. Preferably carried out at 200 to 400 ⁰ C _f in particular at 250 to 35O ° C *

Examples of non-basic metal salts which can be used in the process according to the invention are 3alae _f die aich from Li _t Ua _p K _f Ca, Mg, Cd _f Al, Cr _t Ti _f Tl _r V ₁ In »Zn _f Mn _r Fe, Sb , Co and Hi on the one hand and from öchwefeü-. On the other hand, derive phosphoric or a hydrohalic acid _t in particular from hydrofluoric and ealic acid _{r «}

As mentioned ready v / urde _f can be using the same starting compounds in the method of the invention UmEetzunßSprodukte two categories obtained »ämlich lactones one hand and on the other hand unsaturated carboxylic acids. It can, however, product UmsetzungB-in connections in one of these two categories predominate, possibly so much that _for the connections of the other category in vernachläesigbaren shares or are virtually non-existent. On the other hand, compounds of both categories can also arise in substantial quantities, possibly even in roughly equal proportions,

One can see the Mo! Ratio of the connections between the two categories set in the conversion product by the reaction conditions, e.g. by the type of catalyst, the reaction temperature and the prints,

As a rule, one obtains urno higher proportions of Laotons and urneo lower proportions of unsaturated carboxylic acids, the lower the reaction temperature iet ₀

It should be noted that when using salts belonging to the group of so-called "Lewis acids", such as SbCl ,, AlCl ,, PeCl, or ZnCl ₂ * ala catalysts, there is a tendency towards the predominant formation of unsaturated carboxylic acids »However, this is No rule of thumb If salts are used as catalysts that cannot be referred to as "Lewis acids", such as the sulfates, phosphates and halides of Li _P Wa, K, Ca, Mn, Co or Ni, there is the tendency towards the formation of lactones as main products _c

The nichtbasiechen metal salts preferably used are the fluorides and in particular the chlorides, the preferably used "Lewis Sliure" is zinc chloride _c The salts preferably used _t not to the Lewis acids include, LiCl and CoCl ₂ are =

Although one bonsäure when using a single ß-oxy or fl-Chlorcar ale Auegangsverbindung generally a single lactone is obtained as a product, the inclination can the formation of mixtures of isomeric unsaturated carboxylic acids consist »Z ₀ B are in the reaction mixture usually Angelica and tiglinic acid $> and even <¥ -A "thylaeryl acid found if oxy- or chloropivalic acid is used as the starting compound

The catalysts used in the process according to the invention contain a particulate and porous support material

a specific surface area of at least 0.1 m / g ₀ If one

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all main products want to receive lactones »should die Speaiflache In general, the maximum surface area is 5 m / g. The education unsaturated carboxylic acids, however, is promoted »if the spe-

Specific surface area is about 100 m / g.

Any conventional catalyst support material can be used use. In general, however, aluminum trioxide is preferred, Silicon dioxide or aluminum silicates, as well as mixtures of such compounds o If you want to produce predominantly lactones, aluminum nitrate dioxide is particularly preferred, if, on the other hand, unsaturated ones Carboxylic acids are desired as main products, beiondtr Silicon dioxide.

The proportion of the metal salt or salts that are applied to a Carrier applied can be within a wide range. In general, you get very good results if you a metal content of 0.1 to 7% by weight, preferably of 1 up to 4 parts by weight, based on the carrier, used.

The carrier can be coated with the metal salt * or metal salts in a manner known per se. Very satisfactory results are generally achieved if the carrier is first impregnated with a solution, in particular an aqueous solution, of the metal salt or metal salts, the excess solution is removed and the impregnated carrier is dried. In the last stage of the process, the carrier can be callined if necessary or optionally. The impregnation can be carried out at Haumtemperatur or ■ aasig detected temperature "Drying is iw * ec" äsaig won at temperatures from 50 to 120 ⁰ C, preferably from 60 to 80 ₉ 0. Bie temperature it bsiüi calcining be expedient

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moderately from 200 to 500 C. Further, it may sweokmäseig Ain, dleee sequence of process steps (impregnation, drying, and optionally luletst Galsinieren) once or more repeating su "before the catalyst is used obtained leg erfinduzigegeafttaen method.

In the process according to the invention at Horaaldruok, however , you can also work at overpressure or underpressure. It is preferable to work at pressures of 10 to 100 Torr, in particular from 20 to 50 Torr mixed inert diluent gas. Examples of suitable inorganic diluent gases are nitrogen, neon, helium and xenon. However, it is also possible to use vapors of organic compounds such as vapors of at least one paraffinic hydrocarbon, ester or lower alcohol, preferably methanol or ethanol, as well as vapors of various acids, such as pivalic acid, higher ketones such as methyl isobutyl ketone, and aromatic compounds such as nitrobenzene or toluene The preferred inorganic gas is nitrogen, while the preferred organic compounds are the aromatic compounds, as these apparently act as synergists »Of course, a gaseous mixture of one or more inorganic and / or one or more organic compounds can also be used as a diluent

The molar ratio of starting compounds can be used in the heating zone to the catalyst lie within a wide range. However, it is preferable to work in such a way that there is a constant excess of water of the catalyst, based on the AusgatigavOTMöduageae has available »One can 100 moles or more, is.B» 1000 moles or

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use even 10,000 Hol catalyst per mole of the AuBgangeverbindungen <> The proportion of matched with the catalyst per unit time in contacting the starting compounds may be within eineβ wide range _c The related to the weight Rauageschwindigküit, d "h = the per unit time and per part by weight of The amount of starting compounds passed through the reaction zone of the catalyst (carrier + at least one non-basic salt) was expediently 0 _f 2 to 5 kg / kg, h, preferably 0.5 to 2.5 kg / kg _e ho

The reaction product obtained in the process of the invention can be worked up by any known process, preferably by distillation any unreacted starting compounds contained therein can be recycled or reinstated.

Both types of reaction products obtained in the process of the invention, in other words the unsaturated aliphatic carboxylic acids on the one hand and the lactones on the other hand are as Intermediate compounds can be used in organic synthesis processes, in particular for the production of macromolecular compounds, where they homo- or copolymerized with other suitable comonomers will.

The process according to the invention can be continuous or semicontinuous or carried out discontinuously

When carrying out the process according to the invention on an industrial scale, it may be advantageous to use a so-called "alternating Reactor system "to work, which includes several reactors" The implementation takes place in at least one reaction

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tor _F while in at least one other reactor the catalyst, which has been consumed in terms of activity, is regenerated by burning off carbonaceous deposits.

The example explains the invention _o

example

In a tube reactor aue glass with an IXirchnieeser of 1.5 om and a total length of 75 cm, which is filled with the respective catalyst over a length of 26 cm, becomes a number of Experiments carried out The starting compounds are heated to the required reaction temperature in a preheating zone before they are introduced into the reactor, Aueser in 2 attempts In all cases, the catalysts used contain the same carrier, namely pellets made of aluminum nitrate oxide with a diameter of 3 to 5 mm and a specific surface area of a few

less than 5 m / g, a pore volume determined by the nitrogen method of 0.017 ml / g or a pore volume determined with water of 0.20 ml / g. The catalyst is always prepared by treating the respective support with a metal salt as follows: layers:

In each case 1.16 g of carrier are stirred into 1 liter of an aqueous solution of the respective metal salt at room temperature. The metal salt content of the aqueous solution, expressed in wt. Kach the impregnation of the support is filtered off and this getrocknetο at 60 G Schlieselich it is calcined for 2 hours at 500 ⁰ C, unless otherwise indicated andereβ _o

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In all experiments, monochloropivallneic acid is used as the output compound. The respective reaction product is used to determine the percentage degree of conversion, based on the monochloropivalic acid used, as well as the percentage yield of pivalolactone (referred to as "yield of L") or of unsaturated carboxylic acids (referred to as "yield of UC" ) _{s in} each case based on the converted monochloropivalic acid analyzed.

In each of the experiments, a mixture of pivalolactone and iaoraeren unsaturated carboxylic acids is obtained, namely from Angelica and tiglinic acid, as well as of ethylacrylic acid, It is found »that with predominant production of pivalolactone by recycling or reinstallation of the unreacted Monochloropivalic acid achieved high overall yields of pivalolactone can be.

The catalyst used in Experiment 1 contains 2.4 wt Jt LiCl, based on the Slower The reaction is carried out at a pressure of 40 Torr and at a temperature of 300 ⁰ C. The space velocity defined above, based on the weight, is 0.75 kg of M ^ noehlorpivalic acid / kg of catalyst. H",

The catalyst used in Experiment 2 contains 1% by weight of LiF, related to the carrier. The reaction conditions correspond those of experiment 1.

Experiment 3 differs from Experiment 2 only in that the reaction temperature is 275 ⁰ C instead of ⁰ 3CO C.

Experiment 4 differs from experiment 1 only in that the catalyst contains 2.4 G3W "- # HaCl (instead of LiCl),

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based on the carrier “-.

Experiment 5 differs from experiment 1 only in ^{"j 5} that the catalyst is 2.4 wt _o ~ # LigSO. (Instead of LiCl), based on the carrier.

Experiment 6 differs from experiment 1 only in that the catalyst contains 2.4 wt .- # CaClp (instead of LiCl), related to the carrier »

Experiment 7 differs from experiment 6 only in that the reaction temperature is 275.degree. C. instead of 300.degree.

Experiments 8 to 16 differ from experiment 1 in that the catalysts contain the following salts instead of LiCl; TlCl, BiCl _5, CuCl _2, CdCl _2, HgCl _2, TiCl _5, MnCl _{2, 2} HICL bswo CoCIpβ In the preparation of these catalysts, the calcination (Runs 8, -9, 12 and 13) leads at 25O ⁰ C or at 400 ^° C. (experiment 11) or at 300 ^° C. (other experiments).

In Verβuch 17 the catalyst contains 0.5 wt _o -S6 ZnCl _2, based on the carrier. The temperature of calcination is 200 ⁰ C ₀ The pressure is 20 Torr, the reaction tempera door 275 ⁰ C ₀

In experiments 18 to 19, the same catalyst is used as in experiment 1. In experiment 20, the catalyst contains 2.4% by weight of CoCl ₂ (instead of LiCl), based on the support. In experiments 18, 19 and 20, the same heating temperature and pressure as in experiment 1 are used. The monochloropivalic acid used as the starting compound is, however, in each case with an organic compound, namely in experiment 18 with nitrobene sol and in experiments 19 or " 20 old foluene,

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diluted where in all 3 experiments the same parts by weight of the respective diluent on the one hand and the monochloropivalic acid on the other hand are used. The space velocity based on weight for the mixture of monochloropivalic acid + diluent is 1 _f 5 kg / kg> h _r so that the space velocity applicable to monochloropivalic acid alone is 0.75 kg / kg _e h as in experiment 1

Run 21 differs from Experiment 18 _t dasβ only in the diluent used is isobutyl ketone used and the DAEs based on the weight space velocity is slightly lower. This is l _f 4 instead of 1.5 kg / kg. h for the mixture ,, doh. 0 _t 7 instead of 0.75 kg / kg <, h for the monochloropivalic acid alone * In experiment 22, the conditions correspond to those of Ver ~ Euch 21p, but the weight-related space velocity for the mixture is 0 _r 4 kg / kg <■ h _r those for monochloropivalic acid alone 0.2 kg / kg ₀ ho

In the tests 23 to 28, the diluent is toluene, respectively, wherein the weight ratio of toluene to the dee Monochlorpivalinsäure in the experiments 23 to 25 1 i l _f in the experiments, however 2SVm 28 4 ι 1. The catalyst carrier in the experiments 27 and 28 also consists of a commercially available silica-Aluminiumtrioxydo The catalysts used in the experiments 23, 24, 25, 27 and 28 each contain 5 wt _e -j6 LiCIp based on the carrier. The catalyst from experiment 26 contains 10 Orew _e - # LiCl, based on the carrier "

The table below shows the results of all of the aforementioned experiments «.

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!Tabel

attempt Degree of conversion of the Spoil Spoil Monochloropivalin at L ( to UC, acid * ° f> 1 30th 75 4th 2 45 51 4th 3 25th 65 2 4th 16 76 7th . 5 20th 78 6th 6th 36 59 6th 7th 19th 74 4th 8th 14th 74 6th 9 10 63 8th 10 22nd 51 10 11th 13th 71 9 12th 14th 70 8th 13th 15th 55 19th 14th 26th 73 7th 15th 24 78 5 16 33 74 5 17th 78 5 52 18th 32 80 3 19th 38 76 5 20th 50 72 8th 21 38 76 4th 22nd 41 72 5 23 34 82 3 24 41 75 4th 25th 48 69 5 ze 40 82 3 27 48 80 3 28 57 77 4th

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Claims (1)

P atentana application 'Process for the elimination of water from ß ~ oacycarboxylic acids or of HCl from fi-chlorocarboxylic acids, which differ from unsubstituted ones Carboxylic acids of the general formula I R ¹
R ³ - C - COOH (I) 12 3
derive, in which R, R and R ^ are identical or different and alkyl radicals with 1 to 4 carbon atoms, characterized in that the starting compounds in the vapor phase at a temperature above 100 ⁰ C ₉ but below the temperature at which the starting compounds and / or the reaction products begin to decompose, brought into contact with a solid catalyst which consists of a catalyst carrier coated with at least one non-basic metal salt derived from at least one such inorganic acid, which is derived from the salts through »B>, 0 or HCl split off from the starting compounds during the reaction is not (are) released» 2 "Process according to claim 1, characterized in that the conversion is carried out at temperatures from 150 to 450 ⁰ C, preferably from 200 to 400 C, in particular from 250 to 35O ⁰ C," 3o method according to claim 1 or 2 _S characterized in that the radicals R and R ^ Met !:? Lgroupei \ sind \ * nO- ues? R reads a ^ thfl- ^ the Msthj! group is * 009810 / 178S 4ο Method according to claim 3 “thereby geken n, - = draws that the starting compound is oxypivalic acid used 5ο method according to claim 3 »characterized in that that the starting compound is chloropivalic acid used 6 ο method according to claims 1 to 5? characterized by »Qt _F that at least one non-basic metal chloride is used ,, 7o method according to claim 1 to 6, characterized in that one or more non-basic Salts of lithium and / or sodium and / or calcium and / or manganese and / or nickel and / or cobalt are used, 8 »The method according to claims 6 and 7» characterized in that lithium chloride and / or cobalt chloride used 9c method according to claim 1 Ms 6, characterized in that that you have at least one to the class of Metal salt belonging to "Lewis acids" is used, 10 · Process according to claims 6 and 9 * characterized in that zinc chloride is used » 11. The method according to claim 1 to 10 _f ä a. ά u τ Q h characterized that the catalyst contains a moderate and porous support. 009810 / 178i 12 e method according to claim H ₁ . characterized! that the carrier has a specific surface 2
of at least 0.1 m / g o Having 13r method according to claim 12, characterized in that the gekennzeichne t _r! Support has a specific surface area of at most 100 m / g and preferably silicon dioxide is " 14ο The method according to claim 12 _f, characterized in that the carrier has a specific surface of at most 5 m / g and preferably aluminum trioxide is. 15 β method according to claim 1 to 14, characterized in that the catalyst has a proportion of 0.1 to 7 parts by weight jG, preferably from 1 to 4 percent, - # _t based on the carrier contains at least one non-basic metal salt. 16. The method according to claim 1 to 15, characterized in that the conversion at a pressure of 10 to 100 Torr, preferably from 20 to 50 Torr, carried out 17ο Method according to Claims 1 to 16, characterized in that the conversion is carried out at a harm rate of 0.2 to 5 kg feed / kg catalyst ₀ l ·., Preferably from 0.5 to 2 _f 5 kg feed / kg catalyst. h, performed 0 0 9 8 10/1785 18, method according to claims 1 to 17 »characterized that the gas phase contains at least one diluent 19 ο method according to claim 18 _P characterized; that the gas phase contains nitrobenzene and / or toluene vapor as a diluent » 2Oo method according to claim 1 to 19 _t characterized? that at least 100 moles of catalyst are used per mole of the starting compounds » 009810/1785