DE1014088B - Process for the preparation of primary alcohols - Google Patents

Description

GERMAN

It is generally known that certain organometallic compounds are able to react very easily with oxygen. For example, the alkyl and aryl compounds of the alkali metals, magnesium, zinc, boron, aluminum and some other metals are spontaneously flammable in air. From this known property nothing can be inferred about the nature of the first products of the action of oxygen on these metal alkyls. You can find out more about this by reacting such organometallic compounds under the mildest possible conditions, for example with dilute oxygen and / or in solutions. A number of experiences with experiments of this kind have become known from the literature. It is found that even under such mild conditions, the reactions ¹ S NEN of the organometallic compounds with oxygen slightly proceed smoothly and that usually a plurality of reaction products are thereby obtained. Among these are often the alcohols corresponding to the organometallic compounds. According to Müller and Töpel (reports of the Deutsche Chemischen Gesellschaft, Vol. 72 [1939], pp. 273 to 290), lithium alkyls go very smoothly into lower alcoholates when oxidized with oxygen, which can be converted into alcohols with water in a known manner. This reaction of the lithium alkyls is of no practical importance, since the organic lithium compounds are usually produced from the corresponding chlorides, which in turn are obtained from the alcohols.

Magnesium compounds, e.g. B. Grignard compounds do not produce uniform compounds during autoxidation, so that oxidation has little preparative value (see Franz Runge, " Organometallverbindungen ", Stuttgart, 1944, p. 299).

Organic compounds of another element of Group II of the Periodic System, zinc, produce a one-sided oxidation with oxygen according to R. Demuth and V. Meyer (reports of the German Chemical Society, Vol. 23 [1890], p. 396) Peroxide of the formula C ₂ H ₆ - Zn - O - O - C ₂ H ₅ . The second ethyl residue remains unaffected by the oxidation.

Finally, the oxidation of the boron alkyls regularly continues with the formation of monoalkyl boric acid dialkyl esters stand, even if one re-oxidizes with pure oxygen (Krause-Grosse, »Chemistry of the organometallic Connections ", Berlin, 1937, pp. 199 to 200).

With regard to this different behavior of the lithium, magnesium, zinc and boron alkyls, in do not foresee in any way how the aluminum alkyls will behave.

It has now been observed that aluminum hydrocarbons, in particular those organic aluminum compounds which contain the group —CH ₂ - al ( ^{a1 = 1} I ₈ Al), can be prepared using suitable processes
primary alcohols

Applicant:

Dr. Dr Eh Karl Ziegler,
Mülheim / Ruhr, Kaiser-Wilhelm-Platz 2

Dr. Dr. E. h. Karl Ziegler, Mülheim / Ruhr,
has been named as the inventor

chose experimental conditions with very good yields in many cases, practically quantitatively, to oxidize the corresponding aluminum alcoholates with the grouping - CH ₂ - O - al. According to the invention, aluminum _{hydrocarbons which contain aluminum bonded to the group —CH 2} — CHR ₁ R ₂ , in which R ₁ and R _{2 are} hydrogen or any hydrocarbon radicals, are autoxidized and the aluminum alcoholates obtained are decomposed with water and / or acids. As a by-product, alumina is also obtained in a particularly pure form.

Today, aluminum alkyls can be produced very conveniently and at low cost by several processes will. In particular, the processes of Belgian patent 535 235 have the aluminum triisobutyl very easily made available, and because of this material according to the method of the Belgian patent 540 135 through sales with olefins the saturated aluminum hydrocarbons corresponding to the olefins in great variety can be obtained, the isobutene being recovered according to the following equation:

C ₄ H ₉ al + C _n H _2n = C _n H _{2n + 1} - al -f- C ₄ H ₈

the isobutylaluminum acts here practically like aluminum hydride, and the conversion of the olefins into the corresponding aluminum compounds of the saturated hydrocarbons simply results ^{in the addition of 1} Z _{3 AlH 3} to the olefin. The costs of this conversion are essentially only due to the expenditure for the aluminum and the hydrogen. However, this is relatively very low, especially in the case of olefins of not too low a molecular weight in relation to the amount of olefin converted.

Another method to get aluminum hydrocarbons is that of the German patents 917 006

709 658/404

3 4

and 889,229. In both patents the addition of is extremely rapid; the last requires a longer postoxyethylene to z. B. aluminum triethyl described, and dation at ordinary or slightly increased although in the German patent 917 006 the addition of temperature. It is therefore expedient to start the autoxy relatively little ethylene (up to 6 molecules), in the dation with a gas containing little oxygen in German patent 889 229 that of more ethylene. 5 to, for example a nitrogen mixed with little air, and In each case arise from the aluminum trialkyl, the oxygen concentration increases gradually in the process ₂ H ₅ - (C ₂ H ₄ ) “al, and these, too, can expediently work with pure oxygen. In any case, of course, according to the case according to the invention, the gases used for oxidation must be very well dried in processes with oxygen into alcoholates or alcohols, because otherwise carbon conversion through side reactions. As a result, as can readily be seen from hydrogen residues in non-oxidized form as carbon, the higher primary fatty alcohols are accessible to ethylene from hydrogen in the process according to the invention. whereby the yield goes down. Of course, higher fatty alcohols of the same type can be obtained during autoxidation, also with the aid of aluminum triisobutyl, and the oxygen can be fed to the convenient carrier for aluminum hydride at one point.

when using long-chain paraffins, e.g. B. the high-boiling In many cases, the resulting aluminum

Part of the Fischer-Tropsch synthesis, initially cracking, alcoholate liquids of fairly low viscosity Products are created that do a very high percentage. In these cases you can use the autoxidation content of α-olefins. These then go with the 20 carry out the undiluted aluminum alkyl; However Aluminum triisobutyl in higher primary aluminum must then be especially pre-alkyl at the beginning of the experiment over, from which over the autoxidation visible in the measurement of the oxygen content of the oxy-aluminum alcoholate and alcohols can be obtained. be ding gas mixture. In other cases it is

In all manufacturing methods described here, indicated to work in the presence of solvents, those of the starting materials of the process according to the invention are primarily aliphatic or aromatic rens, the aluminum on a primary carbon atom is hydrocarbons as a diluent in question, bound. That depends with certain regularities to ensure the highest possible yields

Together, the fertilization in the formation of such aluminum compound alcohols is to be observed in the process according to the invention and that of K. Ziegler in the still pay attention to the following. In the presentation of the Zeitschrift für Angewandte Chemie, Vol. 64, p. 324, 3 ° aluminum hydrocarbons are used as they were originally written. Therefore, according to the invention materials are used for the process according to the invention, the process according to the invention will, as a rule, very predominantly, it occasionally happens that primary alcohols are obtained as reaction products. A particular advantage of the products, not only of compounds of the general form of the present invention, is to be seen when they _{form with R 3} Al, but also in more or less large amounts in combination with the various production quantities of those of the formula R ₂ AlH. Also this · ^; ways for aluminum alkyls is used. So far hydrogen on aluminum containing aluminum ^! In fact, it was usually not possible, without large hydrocarbons, according to the invention, primary holates or alcohols can be oxidized to produce a detour, for example through the addition of water. It is therefore possible to obtain these alcohols from olefins. The addition of water to a hydrogen atom on aluminum containing aluminum »to _{α-olefins of the type R - CH = CH 2} with acids leads, as is well known, always as equivalents to secondary alcohols of the formula for the compounds of the general formula AlR ₈ i R - CHOH - CH ₃ , and asymmetrically disubstituted. Alone the yields of alcohols, ierte Ethylenes of the formula R ₂ C = CH ₂ in the oxidation of such compounds are essential water addition with acids tertiary alcohols. After lent lower yields than those obtained in the process according to the invention, they can very easily be obtained by autoxidation of compounds of the form AlR ₃ via the corresponding aluminum compounds. Of course, only a maximum of 2 alcohol moles can in principle be converted from a compound of primary alcohols of the formula R ₂ CH - CH ₂ OH in relation to R _{2 AlH.} Thus, according to the invention, per mole of aluminum compound are formed, but if processes would not only involve many already known alcohols compared to this already reduced amount, there would also be a great many completely new, so far only yields of about two thirds of the theoretically unknown substances become accessible. table amount received. The missing third is in the

For the sake of simplicity, all chemical reaction products in the form of the hydrocarbons RH tongues have been explained on formers that have found an equivalent. Apparently the first product of action al = ¹ I ₃ Al is contained. In reality, one always has to do from oxygen to a compound R ₂ AlH a hydro, first of all with aluminum trialkylene of the general peroxide R ₂ AlO O H. This contains a mobile water, my formula: substance atom, which then contains a radical R in the form of

R RH from the not yet oxidized portion of the aluminum

../_ "Makes minium connection free. ^:;

\ If one wants to avoid losses of this kind, one has;

R 60 ensure that the starting materials for the ö'xy ^ ■■ * ■

dation as far as possible no such organic aluminum ^!

In the course of autoxidation, the compounds contain miniumhydrogen compounds. One can ^{achieve 1} in the order by various measures, e.g. B. there-

_{nT? nT? n} by that one in the preparation of the aluminum alkyls

/ ^U / ^UK / ^UK 65 according to the procedure of Belgian patent 540135

Al; —R Al ς — OR and Al —- OR next works with excess hydrocarbon

\ jj \ jj OR ^unc ^ this excess as gently as possible with a *

as low a temperature as possible, which is also iri>

above. The oxygen uptake in the individual stages of the variant is possible by first adding & | occurs with different degrees of ease. The first two are oxidized and in the presence of the excess olefin

5 6

Olefin is then subsequently stronger than that in the oxidation. It is therefore best to set up the apparatus in such a way that aluminum alcoholate formed is separated off by distillation. that one has the oxygen uptake under control and if one wishes, which especially in the case of olefins of relatively, only breaks off when ^{the case can be above at least 1} J ₂ up to a high value, the carbon used no more oxygen absorbed hydrogen for 1 hour as possible completely using a 5. The gases used are very carefully due to an excess of the aluminum compound in the desiccant, e. B. to 400 ° heated, dehydrated speaking alcohol, it can be indicated and applied to pumice stone or potassium hydroxide to dry the hydrocarbon first with excess magnesium perchlorate. During the aluminum triisobutyl to the corresponding aluminum oxidation, the initially thin aluminum compound will be converted. Under these circumstances bilio trioctyl is viscous, but the reaction can be carried out without the regular reaction products or compounds. The gene finally obtained of the type R ₂ AlH contains, since, as has been described in the thick oil aluminum octylate by the addition of the method of patent 942 026, water and decomposes with heating. Then aluminum isobutyl is easily driven in the heat, an isobutylene, the octyl alcohol formed is lost by steam and converted into diisobutylaluminum hydride. 15 distillation. The oil which has passed over with the distillate In these cases it is expedient, after the treatment, the olefin is separated off and dried over potassium carbonate, the reaction is carried out with the aluminum triisobutyl. Then it is distilled, expediently in vacuo. The product is again treated with an olefin before the oxidation, 320 to 350 g of the completely constant at 81.5 ° / 8 mm, expediently after-treated with isobutylene, at the lowest possible boiling primary normal octyl alcohol from off temperature, is obtained, in order to all of the reaction shown Smell quality.

Mixing existing Al-H-bonds in Al-R-Grup- The residue remains in the steam distillation

pen, especially when using isobutylene in iso- an aluminum hydroxide pulp from which the aluminum butyl radicals convict. As a by-product, hydroxide is easily formed in a known manner by filtration or then separated a certain amount of isobutyl centrifugation during the oxidation and then through a alcohol. For this, however, the conversion of the dehydration into an alumina takes place at a very high level set, corresponding to the desired reaction product - degree of purity can be converted, the olefins in the alcohol are much smoother than when. .

this aftertreatment with an olefin is omitted. eispiei

As a particular advantage of the invention, one initially provides according to Example 3 of the Belgian

In general, it must be said that a solution of aluminum triplic (phenylhydrogen mixtures containing ethyl) in hexane can be used without further ado and oxidizes this in the example 1 only partly from olefins of the suitable structure described way. The work-up carried out as in Example 1 (ie from olefins which _{contain the group = CH 2} ) leads to phenylethyl alcohol. The desired reaction products are then C ₆ H ₅ - CH ₂ - CH ₂ - OH from the boiling point 98 to the end of the oxidation in the form of the corresponding 35 101 ° / 8 mm or 220 ° at ordinary pressure, as aluminum alcoholates of which exist all that corresponds to the reference. The yield is starting olefins admixed inactive hydrocarbons - about 70% of theory, substances extremely easily by distillation,. .

can optionally be removed in vacuo. The example

Decomposition of the non-volatile aluminum alcoholates, 40 10 kg one by cracking from higher fishermen remain in the residue, then immediately provides product obtained with Tropsch paraffins from the boiling water Reaction products that practically exclusively point 180 to 230 ° with a solid by bromine titration Alcohols exist and no other carbon olefin content of 8 mol olefin / kg and one Contain more hydrogen. This is an advantage of the α-ol according to the invention, which is determined spectroscopically in the infrared Method compared to other known 45 content of 5.8 mol / kg were initially with 3 kg aluminum methods, which also mixed olefins in oxygen-containing miniumtriisobutyl and then according to Example 5 Allow bonds to be transferred, e.g. compared to that of the Belgian patent 540 135 at 120 to 130 ° in a vacuum so-called Oxo process. As is known, this can be converted into the aluminum compound. The educated if one looks at the preparation of pure reaction products, solution of the aluminum alkyls in the indifferent ones not working towards hydrocarbon mixtures of 50 accompanying substances of the ct-olefins was then turned into a high large boiling range, because the separation of the cylindrical and the outside provided with water cooling Aldehydes formed as reaction products are transferred from the iron vessel and carefully at first, later like-boiling hydrocarbons become more and more intensive with very well-dried air due to distillation not possible. blow. The cooling of the reaction mixture is regulated

. 55 and the gas velocity so that the temperature

Example 1 does not exceed + 30 ° if possible. Finally increases

With 366 g of aluminum-tri-n-octyl, produced after the temperature is raised to 50 ° and still about oxidized following the procedure of Belgian patent 540 135 and 2 hours with pure oxygen. The thus obtained Aluminum triisobutyl was solution of the aluminum compounds formed in a circulation apparatus Blown nitrogen through. The cycle was followed by a 60 alcohol is then transferred to a still Carefully place oxygen in such a way that the and by heating in vacuum as completely as possible Oxygen content in the circuit was about 5%. That freed from the hydrocarbon components. You hang up Aluminum-tri-n-octyl heats up, and that related an absolute freedom of the alcohols to be obtained from The reaction vessel is expediently cooled from the outside. In hydrocarbons special value, so one can im the extent to which the heat in the reaction vessel 65 is followed by the expulsion of the hydrocarbons becomes lower, the oxygen content of the liquid aluminum circuit remaining in the residue is increased initially to 10 to 20%, and finally alcoholate still superheated vapors go to a relatively low level one over to pure oxygen. The oxidation requires boiling hydrocarbon, e.g. B. Benzene, blow through, 3 to 8 hours depending on the intensity of the cooling. whereupon the last to the liquid aluminum alcoholate In the end, the oxygen uptake slows down 70 residues of the higher hydrocarbons that are still adhering

be driven off, or one uses a very effective continuous to drive off the hydrocarbons working thin-film vacuum evaporator.

In any case, you get the oily alcoholate, which then is expediently worked up by decomposition with water according to Example 1. The higher boiling parts of the The alcohols obtained are finally separated from the aluminum hydroxide pulp by distillation superheated steam in a vacuum. The aluminum hydroxide pulp can easily be recovered by calcination. can be converted into pure clay. The entire organic content of the distillate is collected.

The amount of raw alcohol to be obtained depends somewhat on the specific starting olene used. In a special case, for example, 6 kg of crude alcohol were obtained, which can be further broken down by fractional vacuum distillation. The individual fractions to be obtained here naturally depend on the sharpness of the hydrocarbon cut used. In the fraction used, boiling from 180 ° to 230 °, small amounts of C ₈ olefin were also regularly present, so that the first alcohol obtained in the distillation on an effective column in vacuo tends to be the primary octyl alcohol. You can go through

ik d

In a similar way, the alcohols with the formulas can also be obtained from limonene and camphene

CH ₃ - (

HH ₂
\

Hn

H ₉ C-CH-

CH,

c — ch:

XH ₂ -OH

CH,

-CH,

CH ₃

H ₂ C-CH-CH-CH ₂ -OH

be won.

Example 6

The procedure of Example 7 is first carried out of the Belgian patent 540 135 336 g "dimeric dodecene" (manufactured according to the method of the German patent

further distillation on an effective column of 25 878 560) with aluminum triisobutyl in the aluminum series after all primary straight-chain fatty alcohols with compound 9 to 16 carbon atoms obtained, which, however, if one starts from a hydrocarbon prepared according to Fischer-Tropsch, including certain amounts of methyl-branched ones Fatty alcohols are added. The pure primary fatty alcohols, especially the higher limbs

Al

- CHo - CH:

with 12 or more carbon atoms, can be easily extracted from the appropriate fractions by cooling to Bring to crystallize and then separate out by suction or centrifugation.

Example 4

The oxidation of a higher aluminum alkyl, which is obtained by heating together, proceeds in a very similar manner of 114 g of aluminum triethyl -f- 420 g of ethylene in an autoclave at 100 to 110 ° until the ethylene pressure disappears. As a solvent toluene is used (twice the volume of the aluminum alkyls). The work-up carried out as in Example 3 supplies the whole range of primary normal fatty alcohols, starting with n-hexyl alcohol up to the alcohols with 18 to 20 carbon atoms with one clear maximum frequency for n-dodecyl alcohol.

Example 5

118 g of the aluminum compound to be obtained from 1-venylcyclohexene (3) were diluted with 200 ecm of octane and subjected to oxidation according to Example 1. Working up gives the tetrahydrophenyl alcohol following formula:

over and oxidized this with 600 ecm of toluene, diluted in the manner described in the other examples and receives 300 g of the alcohol

NO-CH ₉ -CH:

, l / i η XZo

^ 10 "2I

H,

60

HC

HC

C-CH ₂ -CH ₂ -OH

IV

CH

H ₂

This alcohol is a colorless oil with a boiling point of up to 1075 mm. He shows < = 1.4831. The alcohol is a colorless oil with a boiling point of 164 to 166 ° at 10 ~ * mm.

Claims (7)

Claims. 1. A process for the production of primary alcohols, characterized in that aluminum hydrocarbons, the aluminum to the group -CH ₂ -CHR ₁ R ₂ contain bonded, in which R ₁ and R _{2 are} hydrogen or any hydrocarbon radicals, autoxidized and the aluminum alcoholates obtained are decomposed with water and / or acids. 2. The method according to claim 1, characterized in that in the presence of solvents is being worked on. 3. The method according to claim 1 and 2, consisting in that the oxidation with only a little oxygen containing gas mixtures started, the oxygen content increased in the course of the oxidation and is finally post-oxidized with high percentage oxygen. 4. The method according to claim 1 to 3, characterized in that at temperatures between 0 and 100 °, preferably between 30 and 60 °, is worked. 5. The method according to claim 1 to 4, characterized in that the starting material for the autoxidation Aluminum hydrocarbons containing as little aluminum hydride as possible are used. 9 10 6. The method according to claim 1 to 5, characterized in that mixtures by distillation of the aluminum that separated when using aluminum alcoholates and only then the aluminum hydride Starting materials The starting materials are decomposed before alcoholates with water and / or acids the oxidation with an olefin, especially with be. Isobutylene, are pretreated. 5 7. The method according to claim 1 to 6, characterized marked, that when using aluminum- Publications taken ^into consideration: alkylene containing distillable admixtures, reports of the German Chemical Society, 72, after the autoxidation has been carried out, see Bei- (1939), pp. 273 to 290. © 709 658/404 8.57