DE2363000A1 - PROCESS FOR THE PRODUCTION OF ALCOHOLS - Google Patents

Description

Process for the production of alcohols

The invention relates to a process for the preparation of alcohols of higher molecular weight by condensation at least one lower molecular weight primary alcohol that is adjacent to the hydroxylated carbon atom has a methylene group; it relates in particular to the condensation of primary alcohols to form alcohol products with a higher molecular weight, especially an improvement in the condensation of primary alcohols with a methylene group adjacent to the hydroxylated carbon atom to form alcohols with a carbon content, which corresponds to the sum of the carbon atoms of the two starting alcohols on the ß-carbon atom are branched.

ÜFach the well-known Guerbet reaction can be a primary odex ¹ secondary alcohol containing a methylene group adjacent to the hydroxylated carbon atom, with itself or

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be condensed with another alcohol of the same class to form a higher alcohol as the main product, which contains the sum of the carbon atoms of the starting alcohols his Aiko "holats exists g sodium" and potassium hydroxide and the like _e have been set up already many theories relating to the mechanism of Heaktion (see _o ζ ,, Β * US Patent · = - provisions 2004350 "2 9 1 033, 2 829 177 and 3 558 16) and ss "there has so far been little agreement (see US Pat. No. 2,762 84-7) what reactions or reactions during the conversion of the lower alcohols in fact, the higher alcohols occur _o Tn the last-mentioned patent is shown further thereon executed = that probably a variety of different Eeaktionen occurs so that the process is very empfindli ch is mid the effect of the respective catalysts cannot be predicted _e

As a result of the overall reaction, a reaction product mixture naturally arises which contains not only the higher alcohols, but also corresponding higher aldehydes and higher unsaturated alcohols, as well as various other byproducts as a result of weaving reactions, the higher aldehydes and the higher unsaturated alcohols and Aldehydes pose few problems since they are converted into the desired higher alcohols when the reaction product is hydrogenated. The other by-products which have been described so far include carboxylic acids and salts and esters thereof _; tana in eggs usually it is desirable ₉ keep their formation minimally au * Sin method sur reduction of Ifabenprodukte that in cL'äs? US Pat. No. 3,328 Q ^ G has been proposed to include the use of "less than 3 mole percent alkali catalyst and the application of temperatures within the range.

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Ches from 200 to 300 ⁰ O, the water formed during the reaction being removed continuously. On the other hand, it is known that in order to achieve acceptable reaction rates, relatively high temperatures (for example 290 ^° C.) and relatively large amounts of alkali: catalyst must be applied or used; however, considerable amounts of undesirable by-products are also obtained under these conditions. It was therefore necessary to adapt the reaction rate to the tolerable by-products in the Guerbet standard reaction.

There has been considerable development activity of various methods to improve the reaction rate of this process while at the same time Reduction or at least no increase in by-products developed. Among the various attempts that include the use of certain phosphates as cocatalysts (US Pat. No. 2,762,847), the use of a special combination of a catalyst mixture consisting of potassium carbonate, magnesium oxide and copper chromite (U.S. Patent 2,971,033), and the use of certain compounds of platinum, palladium, ruthenium and rhodium (US Patents 3,479,412 and 3,514,493).

Much effort has also been devoted to the use of dehydrogenation catalysts, apparently on the assumption that the alcohol starting material is first dehydrogenated prior to condensation in the Guerbet reaction and that by catalyzing this dehydrogenation increases the overall reaction rate (cf. the French patent 784 656, the German patent specification 754 468 and the US patents 2,457,866, 2,757,139 and 2,836,628). To the various dehydrogenation catalysts described in these patents include different connections

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of copper, zinc and nickel. These compounds are along with iron, aluminum, chromium, silver and magnesium also in German patents 748 040, 911 730 and 855 108 mentioned. With these known dehydrogenation catalysts various effects were achieved; for example, US Pat. No. 2,457,866 indicates that zinc stearate as a dehydrogenation catalyst, the condensation of a mixture of 5-ethylnonanol-2 and 2-ethylhexanol-1 catalyzes that, however, to achieve -liner yield of 46%, based on the 2-ethylhexanol, a reaction time of J1 hours is required »In the German patent specification 855 107 is also stated that zinc chloride is an effective catalyst for the Guerbet condensation of Butanol is that, however, as will be shown below, it is much less effective than that proposed by the present invention Improvement of this procedure.

For an explanation of the empirical nature of the catalysis of the reaction, reference is made to US Pat. No. 2,829,177, in which iron (III) ions are used as a promoter for the alkali-catalyzed condensation, while other, closely related materials such as iron (II) ion, are ineffective or too little effect _s are to justify their use.

It has now surprisingly been found that in the Guerbet reaction of primary alcohols with methylene groups adjacent to the hydroxylated carbon atoms one considerably improved reaction speed can be achieved or significantly milder reaction conditions (temperature, Pressure) can be applied when starting the reaction in the presence of certain organic zinc compounds performs which, contrary to the teachings of the prior art, are not dehydrogenation catalysts under the reaction conditions. This not only increases the reaction speed improved, but also the selectivity

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did the overall process essentially retained how shows the hydrogenated product. In addition, as already mentioned above, the reaction product as a whole are hydrogenated to the higher aldehydes and the higher unsaturated alcohols and aldehydes in the corresponding to convict higher alcohol products. With respect to the reaction products resulting from mixtures of alcohol reactants according to the Guerbet standard reaction, i.e. in the case of the simple Alkali-catalyzed condensation of alcohols arise, it has now been found that after this hydrogenation a product is obtained which contains considerable amounts of mixed Contains paraffins, some of which have boiling points similar to those of the desired higher alcohol products and thus cannot be separated using conventional distillation methods. It is believed that this Paraffins from the during the condensation reaction as Dimeric dienes formed by byproducts arise.

With the present invention it is now possible to reduce the amount of these paraffins in the hydrogenated reaction product, which is a direct result of the reduction in the amount of dimers formed during the condensation reaction Serve is. This makes it possible to obtain a higher alcohol product with a higher purity using conventional distillation methods to manufacture. It should be emphasized, however, that the selectivity of the process remains practically unchanged to the extent that it is apparent despite reducing the amount of precursors for that Paraffins (dimeric dienes) a corresponding increase in other by-products occurs, which easily occurs through distillation can be separated. Thus, although the selectivity of the process remains practically the same, what is desired higher alcohol products and the compounds which can be converted into these by hydrogenation, the distribution of the By-product types in favor of increasing the amount of easy separable high-boiling by-products compared to the

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By-products that are more difficult to separate (paraffins) are changed after the hydrogenation of the reaction product.

The invention is a process for the preparation of alcohols with higher molecular weight by condensing at least one primary alkanol with lower molecular weight, which has a methylene group adjacent to the hydroxylated carbon atom, which is characterized in that the condensation in the liquid phase in the presence of an alkali catalyst and a organic zinc compound with simultaneous removal of the formed
Water is carried out, with an alkali metal alcoholate or a precursor thereof which forms the alcoholate in the reaction system as the alkali catalyst, and as organic
Zinc compound a compound of the general formula can be used

0
(E -CO) ₂ Zn (I)

EAR"
(R »_G-C = G-0) ₂ Zn or (II)

(R '"- S0 ₃ ) ₂ Zn · (III)

wherein R ¹ , R "and R" ¹ are each independently saturated or unsaturated, cyclic or acyclic, branched-chain or straight-chain (unbranched) hydrocarbon groups.

The alkanols which can be used according to the invention are
are primary alkanols with methylene groups adjacent to the hydroxylated carbon atoms «These alkanols can be represented by the general formula

R-CH ₀ -GH ₂ OH

C.

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wherein R is a straight or branched chain alkyl group means. Although the number of carbon atoms in the Substituents R is theoretically unlimited, contains R in in practice, preferably from about 2 to about 28 carbon atoms. The preferred primary alkanols are therefore those which are branched or straight-chain (unbranched) are, 4 to JO carbon atoms and a methylene group in proximity to the hydroxylated carbon atom. Examples of these preferred primary alkanols are 1-butanol, 1-octanol, 1-hexadecanol, 1-octadecanol, 1-eicosanol, 1-dodecanol, 1-heptadecanol, 1-hexacosanol, 1-tetracosanol, 1-pentanol, 1-tetradecanol, 3i3-dimethyl-1-butanol, 4 ~ methyl-1-pentanol, 4-methyl-i-heptanol, 3-methyl-1-heptanol, 3,3-dimethyl-1-heptanol, 3,3-dimethyl-1-hexanol, 4,4-dimethyl-i-heptanol, 4, ^ - dimethyl-i-hexanol, 3, -4 - ^ imethyl-1-heptanol, 3 »4 - dimethyl-1-hexanol and the like.

The alcohols can be reacted in pure form or in the form of mixtures. In particular alcohol mixtures, such as e.g. those commonly referred to as "oxo alcohols" and methylene groups adjacent to the hydroxylated carbon atoms are suitable as mixtures of linear alcohols.

The aforementioned alkanols are in the presence of an alkali catalyst, as known per se andv with respect to the Guerbet reaction described in the literature, implemented. These alkali catalysts include the alkali metals, Alkali metal hydroxides, alkali metal oxides and alkali metal alcoholates. The metals, hydroxides and oxides form naturally in the reaction system, the alcoholates, in which the hydrocarbon portion of the alcoholate is the hydrocarbon portion of the alcohol reactant. If previously made If alkali metal alcoholates are used, it is not necessary that they correspond to the alcohol reactants. Examples of suitable alkali catalysts are metallic

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Sodium or potassium, lithium hydroxide, sodium hydroxide, Potassium hydroxide, sodium oxide, potassium oxide, sodium alcoholates, Potassium alcoholates and the like. However, other alkali metal compounds can also be used can be used, provided that they contain the corresponding alcoholates under the reaction conditions form. Such compounds include, for example, the alkali metal bisulfites.

The amount of alkali catalyst used and the effects vary Quantities of this catalyst are known per se. Because large amounts of alkali catalyst lead to increased amounts of lead to undesirable by-products and because of the inventive improved process at low levels of alkali catalyst achieved good reaction rates it is usually neither convenient nor necessary to add more than such an amount of alkali catalyst use that about 4 moles of alkali metal for every 100 moles of alcohol reactants is equivalent to. In general, an amount of alkali catalyst can be used to achieve satisfactory results corresponding to about 0.1 to about 4 moles of alkali metal per 100 moles of alcohol reactants, with preferred Amounts from about 0.5 to about 4 moles of alkali metal, based on moles of alcohol reactants.

As mentioned above, the improvement achieved by the present invention is that the condensation reaction the above-described primary alkanols catalyzed by the above-mentioned alkali catalysts in the presence of certain organic zinc compounds is carried out under the conditions of the condensation reaction are not dehydrogenation catalysts. The organic zinc compounds that can be used are Salts of certain carboxylic acids, ß-diketones and sulfonic acids and they can be represented by the following general formulas being represented:

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(R ¹ -CO) ₂ Zn (I)

0 HR "(R" -CC = C-0) ₂ Zn and (II)

(R " ¹ -SO ^) ₂ Zn (III)

where in the above formulas R ¹ , R "and R ¹ ", independently of one another, are in each case saturated or unsaturated, cyclic or acyclic, branched-chain or straight-chain hydrocarbon groups. Mixtures of these salts can also be used.

The organic zinc compounds defined by the formula I given above include those compounds in which R ^{1 contains} 1 to 30 carbon atoms. Examples of such compounds are zinc salts of acetic acid, butyric acid, propionic acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, eicosanic acid, behenic acid, isobutyric acid, isovaleric acid, isovaleric acid, 2 ~ , Undecylenic acid, oleic acid, linoleic acid, benzoic acid, o-, m- and p-toluic acid, dimethylbenzoic acid, naphthoic acid, abietic acid, tall oil fatty acids, naphthenic acid (mixtures of Cg-Cjq acids, as described by Fieser and Fieser in "Advanced Organic Chemistry", 3 . Edition, 1956, pages 24-7 to 248, indicated), resin acids and the like.

The organic zinc compounds defined by the above formula II include those compounds in which the Substituents R "independently of one another each have 1 to 10 carbon atoms. Examples of such compounds are zinc salts of ß-diketones, such as 2,4-pentanedione (in general referred to as zinc acetylacetonate), 2,4-heptanedione, 3,5-heptanedione, 2,6-dimethyl-3,5 ~ heptanedione, 2,4-honanedione, 3,5-nonanedione, 4-, 6-nonanedione, 3,7-undecanedione, 2,2,6,6-tetramethyl-3,5-heptanedione, 1,3-diphenyl-1,3-propanedione and the like.

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The organic zinc compounds defined by the above formula III include those compounds in which E '"has 6 to 54 carbon atoms. Examples of such Compounds are zinc salts of p-toluenesulfonic acid, haphthalene-ß-sulfonic acid, Benzenesulfonic acid, alkyl and dialkylbenzo! Sulfonic acids, v / orin the alkyl groups have 2 to 24 carbon atoms, such as dodecylbenzenesulfonic acid, octylbenzenesulfonic acid, Didodecylbenzenesulfonic acid, decylbenzenesulfonic acid, Hexadecylbenzenesulfonic acid, ditetradecylbenzenesulfonic acid, Dinonylbenzenesulfonic acid, heptadecylsulfonic acid, Dibutylbenzenesulfonic acid and tridecylbenzenesulfonic acid; Sulfonic acids, those of monoolefins (both 1-olefins and olefins with a lateral or internal double bond), preferably derived from olefins having 8 to 30 carbon atoms are, such as 1-dodecene sulfonic acid, 1-eicosene sulfonic acid, 2-heptene sulfonic acid, 1-pentadecene sulfonic acid, 2-ti? Idecene sulfonic acid and 1-tetradecene sulfonic acid (of course these sulfonic acids derived from monoolefins can also be mixed with hydroxyalkanesulfonic acids, as described in the U.S. Patent 3,409,64? are described, which are all zinc salts form, present); Alkyl sulfonic acids in which the alkyl group contains 6 to 30 carbon atoms, such as decyl sulfonic acid, Dodecylsulfonic acid, 2-ethylhexylsulfonic acid, heptadecylsulf acid, pentadecylsulphonic acid and tridecylsulphone " acid; Cyclohexylsulfonic acid and the like.

The above zinc compounds can be used as such or dissolved in a solvent as in the case of the commercially available Zinc naphthenate is used.

In the Guerbet reaction improved according to the invention catalytic amounts of the organic zinc compounds defined above are used in general by an amount sufficient to add at least 10 ppm zinc metal based on the primary alkanol reactants deliver. Although theoretically no upper limit on

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the amount of zinc that may be present "consists of it should be noted that very large quantities (e.g. 500 ppm) can interfere with the alkali catalyst so that the use of larger amounts of the alkali catalyst than normal is necessary to achieve the desired reaction parameters. Preferably about 50 to about 200 ppm zinc metal, based on the alkanol reactants, is used, but the invention is in no way limited thereto.

The improved reaction according to the invention can in general can be carried out over a wide temperature range, as is known for Guerbet reactions. These temperatures are generally within the range from about 80 to about 300, preferably from about 200 up to about 300 ° C. The particular temperature employed will depend on the primary alkanol reactants used alkaline condensing agents and other process conditions as known.

It is important that the water formed in the condensation reaction is removed as the reaction proceeds, otherwise the oxidation of the alcohols to carboxylic acids is increased, corresponding to a loss of alkali catalyst by the subsequent neutralization of the acids. As already stated in the introduction, the removal of the water take place from the Guerbet reaction by using a dehydrating agent, such as calcium oxide or magnesium oxide, used. However, the water is preferably removed by azeotropic distillation. The latter procedure is particularly advantageous in the condensation of a low molecular weight alcohol, which is below Atmospheric pressure and overpressure is carried out.

When carrying out the method according to the invention, it is

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it is generally expedient to use alkali catalysts which contain a minimum of water, since any water introduced with the catalyst must subsequently be removed during the reaction, as indicated above. That is not to say that water must not be introduced in this way and in some cases it can be very advantageous from a materials handling standpoint to add the alkali catalyst in the form of a reasonably concentrated aqueous solution. It is believed, however, that when using such organic zinc compounds which have limited solubility in the alkanol phase, care should be exercised to avoid the introduction of such amounts of water which would have the effect of preferentially dissolving the zinc compounds and thereby causing the through To prevent the improvement of the catalytic effects achieved by the invention. Such caution should be exercised in particular with organic zinc compounds of the formula I in which R ^{1 contains} fewer than 4 or 5 carbon atoms. Except that the above considerations can influence the course of the reaction, the pressure is not an essential aspect of the process according to the invention. However, it is desirable to maintain the reactants in a liquid state so that sufficient pressure is applied, if necessary, to achieve this physical state. Inert diluents can be used in the reaction, if desired. Such diluents include hydrocarbons such as paraffins, olefins, benzene, toluene, xylene and the like.

As indicated above, the reaction product contains the condensation reaction generally in addition to the higher molecular weight saturated alcohols, higher molecular weight aldehydes Molecular weight and unsaturated alcohols and aldehydes of higher molecular weight and a certain smaller amount

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other by-products. Because of the presence of the aldehydes and unsaturated alcohols and aldehydes it is it is generally advantageous to hydrogenate the reaction product before the product alcohols are separated off. this has the consequence that the aldehydes and unsaturated alcohols and aldehydes with higher molecular weight in product alcohols be transferred, thereby reducing the overall yield of the desired Product is increased.

When separating the product alcohols from the hydrogenated Conventional distillation methods can be used for reaction product, whereby first unreacted alcohols with The lower molecular weight are separated, followed by the product alcohols, while the higher-boiling ones By-products remain in the still residue. When using a single alkanol reactant, the Hydrogenation converts any dimeric diene present in the reaction product to the corresponding paraffin and can be separated from the higher product alcohols by distillation. However, if a mixture of alcohol reactants is used, some of the dimeric dienes are converted into paraffins during hydrogenation, because of the similarity With regard to the boiling points, they cannot be easily separated from the higher product alcohols by simple distillation. This again shows one of the aforementioned advantages of the process according to the invention when using mixed alkanol reactants, in which the distribution of the By-products in the Guerbet reaction from the dimers is shifted to the higher-boiling by-products. By reducing the amount of dimeric dienes in the Guerbet reaction product a lower content of contaminating paraffins is obtained in the mixed product alcohols after hydrogenation and separation by distillation.

The invention is illustrated in more detail by the following examples, without, however, being restricted thereto.

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example 1

To the effectiveness of the improvement according to the invention in relation to the considerable reduction in the reaction time while maintaining relatively mild reaction conditions in the Guerbet reaction and with respect to the Change in the distribution of the by-products, essentially reducing the selectivity of the process for the preparation of higher alcohols and from higher saturated aldehydes, unsaturated aldehydes and unsaturated alcohols, the by simple hydrogenation in which higher alcohols are convertible, are to be demonstrated Comparative tests carried out.

The control experiment was performed by introducing 250 grams (1.58 moles) of 1-decanol and 2.1 grams (0.0318 moles) of KOH pellets (85 % KOH, 15% water) into a Dean-Stark azeotrope - Trap and a 500 ml three-necked flask equipped with a reflux condenser, thermometer and stirrer. The reaction mixture was heated to reflux temperature and refluxed until about 8 ml of water was formed and collected. This corresponded to about 50% conversion of the 1-decanol, with 1 ml of water coming from the KOH pellets and 7 ml v / water from the condensation reaction. The time required for the last 7 ml of water to form was about 7/25 hours. To remove the alkali catalyst, the crude reaction mixture was first washed with 25% iger ^ SO ^ acid and then washed with water. After removal of the water, the entire reaction mixture gaschromat OGR aphis ch analyzed The reaction product was, with an approximately 51 "wt .-% conversion of 1-decanol was found consisted how the analysis showed to about 89 wt -..% Of a saturated alcohol having 20 carbon atoms, about 4 % by weight of an alcohol precursor having 20 carbon atoms (a saturated aldehyde and an unsaturated aldehyde and alcohol), about 5% by weight of a dimeric diene having 20 carbon atoms and about about 2 wt% off higher

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boiling by-products.

In a first attempt according to the invention carried out the above method was carried out with the additional use of 0 _s O32 ml of a Zinknaphthenatlösung (8% Zn), which is commercially available from the company Carlisle Chemical. The zinc naphthenate was completely miscible with the reaction mixture and the amount used was sufficient to provide about 10 ppm zinc based on the 1-decanol. The reaction time required to form the last 7 ml of water was about 2.7 hours. After the crude reaction mixture had been worked up as described in the above experiment, a gas chromatographic analysis was carried out which showed an approximately 53% by weight conversion of the 1-decanol, the reaction product being about 90.4% by weight. from a saturated alcohol with 20 carbon atoms, to about 3.9% by weight of an alcohol precursor with 20 carbon atoms, to about 2.8% by weight of a dimeric agent with 20 carbon atoms and to about 2.9% by weight % consisted of higher boiling by-products.

Another experiment carried out according to the invention was like described above, but this time about 0.18 ml of a zinc naphthenate solution was used to supply about 50 ppm zinc in the reaction system, based on 1-decanol. The amount required to obtain the last 7 ml of water The reaction time was about 1.1 hours. Gas chromatographic analysis showed about 57 weight percent conversion of 1-decanol and a reaction product which is about 86.1% by weight from a saturated alcohol with 20 carbon atoms, about 6.3% by weight of an alcohol precursor with 20 carbon atoms, to about 2.0 wt .-% of a dimeric diene with 20 carbon atoms and about 5j6% by weight of higher boiling By-products.

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A further experiment carried out in accordance with the invention was carried out as described above, but this time about 0.35 ml of a zinc naphthenate solution was used to provide about 100 ppm of zinc in the reaction system, based on 1-decanol. The reaction time required to form the last 7 ml of water was about 1.2 hours. Gas chromatographic analysis showed a conversion of the 1-decanol of about 59% by weight. The analysis showed that the reaction product consisted of about 86.0% by weight of a saturated alcohol having 20 carbon atoms, about 6.7 wt .-% s from an alcohol precursor having 20 carbon atoms to about 1.8 wt .-% of a dimeric diene having 20 carbon atoms and to about 5 wt _.-%} 5 from higher-boiling by-product.

Another experiment carried out according to the invention, which was carried out as described above, but this time the zinc naphthenate was replaced by about 3.5 g of zinc octoate. The zinc octoate was also completely miscible with the reaction mixture and the amount used was sufficient to provide about 2500 ppm zinc based on the 1-decanol. The reaction time required to form the last 7 rail of water was about 1.8 hours. Gas chromatographic analysis showed a conversion of the 1-decanol of about 52% by weight. As the analysis showed, the reaction product consisted of about 87.2% by weight of a saturated alcohol with 20 carbon atoms, of about 8 _? 6 wt -.% Of an alcohol precursor having 20 carbon atoms to about 1.3 wt .-% of a dimeric diene having 20 carbon atoms and from about 2.9 wt .-% of higher boiling by-products.

The data given above are summarized in Table I below.

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CO ■ Ρ- OJ

CD

Reaction 7.25 r ³ 1.3 conversion a kesa C ₂₀ -AICOHOL
(Wt%) , 0 Table I. Service
(Weight , 0 a Zn $ ppm) time (hrs.) 2.7 (Wt%) 89 5 ,8th ΗΒ ^α
(Wt%) 0 1.1 . 51 90 ,1 2 "O 2.0 10 ^a 100 ^a 1.2 53 86 , 0 Reaction product 2 ,8th 2.9 50 ^a 25OC 57 86 , 2 C ₂₀ -AIkOhOl-
precursor
(Wt%) 1 , 3 5.6 a - 59. 87 4.0 1 5.5 b - 52 · 3.9 2.9 c - from zinc naphthenate η aide 6.3 ättif from zinc octoate kills 6.7 unees consisting of 8.6 3; th aldehyde fcnrd and a

and alcohol easily separable _ä higher boiling by-products.

cc CT; CC

O O

- -1" _

It should be noted that the reaction products given in Table I above lead, after hydrogenation, to a total amount of the desired product _{alcohol having 20 carbon atoms which corresponds to the sum of the amounts given of C 20} alcohol and Cp ^ alcohol precursors. The diene is converted into the corresponding paraffin with 20 carbon atoms. It is therefore clear that the overall selectivity for the desired products (Cp ₀ alcohol and Cp ^ alcohol precursors) remains practically the same in each experiment. However, the content of dimeric diene in the undesired by-products is considerably reduced.

Example 2

A number of tests were carried out in which the improvement according to the invention is given with the information in German patent specification 855 107, in which the use of zinc chloride for carrying out the Guerbet reaction for the preparation of alcohols with a higher molecular weight, and also with the use of zinc oxide, a known dehydrogenation catalyst as proposed in the prior art. In each of the experiments, 250 g of 1-decanol, 2.1 g of KOH pellets (85 % KOH) and a certain amount of zinc salt sufficient to produce the amounts of zinc in ppm given in Table II below, based on the 1- Decanol, to provide, into a 500 ml three-necked reaction flask equipped with a Dean-Stark azeotrope, reflux condenser, thermometer, and stirrer. The reaction mixture was heated to reflux temperature and refluxed until about 8 ml of water had been formed and collected, resulting in about 50% conversion of the 1-decanol (1 ml v / water from the KOH and 7 nil water The time required for the formation of the last 7 ml of water was measured and is given in Table II below.

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Belle II also the control experiment from Example 1, in which no zinc was used.

Table II - reaction time Zn-SaIz Concentration temp. 228-248 (Hours.) (ppm Zn) 225-248 7.25 control - 229-245 2.7 oxide 100 225-247 2.6 chloride 100 230-248 1.3 acetate 100 1.2 Octoat 100 1.1 Naphthenate 50.

From the above data it can be seen that zinc oxide and zinc chloride although a certain improvement in the Guerbet reaction with respect to the reaction rate result, but that the organic zinc compounds used according to the invention give reaction rates which are considerably better are than those obtained with zinc chloride.

Example 5

Following the procedure of Example 2, 250 g of 1-decanol, 2.1 g KOH pellets (85% KOH) and 0.05 S zinc acetylacetonate (corresponding to about 50 ppm Zn, based on the alkanol) in introduced the reaction flask. The reaction was started by heating the reaction mixture to reflux temperature and Maintaining the reflux conditions (228 to 247 ° C) until approximately 8 ml V / water has been formed and collected, indicating about 50% conversion of the alkanol. The amount necessary to sanmieln the last 7 ml of water Reaction time was about 1.5 hours.

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Example 4

The effect of the present invention in terms of reducing the reaction time in the Guerbet process was also demonstrated by introducing about 250 g of 1-decanol, 2.1 g of KOH pellets (85% KOH) and 0.08 g of a zinc naphthenate solution ( 8 % Zn) to deliver about 25 ppm zinc, based on the 1-decanol, in a 500 ml three-necked reaction flask equipped with a Dean-Stark azeotrope, a reflux condenser, a thermometer and a stirrer. The reaction mixture was heated to reflux temperatures and refluxed (230 to 245 ° C) until about 8 ml of water had been formed and collected, resulting in about 50% conversion of the 1-decanol (1 ml of water from the KOH and 7 hectoliters Water from condensation reaction) · The reaction time required to form the last 7 ml of water was approximately 1.6 hours.

Example 5

According to the procedure given in Example 2, 250 g of 1-decanol and 2.1 g of KOH pellets (85 % KOH) were mixed with one another and introduced into the reaction flask, then about 0.14 g of zinc octoate (corresponding to about 100 ppm of zinc in solution) added. After thorough mixing, the reaction was carried out by heating to reflux and maintaining reflux conditions (224 to 247 ° C) until about 8 ml of water had been formed and collected, indicating about 50% conversion of the 1-decanol. The reaction time required to collect the last 7 ml of water was about 1.2 hours.

The above experiment was essentially repeated, this time the mixture of KOH and 1-decanol being heated to reflux and the water removed to substantially convert the KOH to potassium decane oxide, after which the 0.14 g Zinc octoate were added. The reflux conditions (225 his

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250 C) were maintained until 7 ml of water were formed and had been collected, which was about a 50% conversion of 1-decanol indicated. The one required to collect the 7 nil of water Reaction time was about 1.2 hours.

Example 6

According to the method described in Example 2, 2108 g of a commercial mixture of 1-alkanols with 16 to 20 carbon atoms and practically no branching (ALFOIj ~ 0-16-20-AlkOhOl), 116 ml of mixed xylenes as diluent, 23.2 g of KOH Pellets (85% KOH) and 2.6 g zinc naphthenate (corresponding to about 100 ppm Zn, based on the 1-alkanols) introduced into the reaction flask and heated to reflux. The reflux conditions (233-272 ° C) were maintained for about 2.5 hours while the water formed was continuously collected. Based on the collected water, the conversion of 1-alkanols was found to be about 80 % .

Example 7

A similar procedure was carried out as in Example 5, but this time about 320 g of an essentially straight-chain commercial mixture of 1-alkanols with 20 carbon atoms and above (ALIOIP -0-20 + alcohol) distilled up to 85% overhead product 24-0 ml of mixed xylenes diluent, 32.0 g of KOH pellets (85 % KOH) and 2.5 g of zinc naphthenate (corresponding to about 100 ppm Zn based on the 1-alkanols) were introduced into the reaction flask and refluxed heated. The reflux conditions (240 to 256 ⁰ C) were maintained for about 4.5 hours, while the water formed was continuously collected. Based on the collected water, it was calculated that about 70% conversion of the 1-alkanols had been obtained.

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Example 8

Another experiment similar to the experiments described in Examples 6 and 7 was carried out by using 500 g ALP03 ^ -Ö-16-20-alcohol, 60 ml mixed xylenes as Diluent, 5.0 g KOH pellets (85% EOH) and 0.7 g Zinc naphthenate (equivalent to about 100 ppm Zn based on the alcohol) was introduced into the reaction flask and refluxed heated. The reflux conditions (230 to 243 ° C) were held for about 2.2 hours while collecting the water formed. Because of the collected water it was calculated to be about 70% conversion of the alcohol had been received.

Example 9

A series of experiments were carried out using the general procedure described in Example 2, but this time the reaction mixture was heated so that the water evaporated without boiling the alcohol, rather than refluxing the water to remove the water while returning the alcohol to the reaction to cook. In each experiment, 250 g of 1-dodecanol, 2.1 g of KOH pellets (85% KOH) and 0.14 x g of zinc octoate (about 100 ppm Zn based on the 1-alkanol) were added to the reaction flask and reduced to about 238 g heated to 242 ⁰ C ". the temperature was maintained formed to about 8 ml of water and had been collected, indicating about 50 / o conversion of 1-dodecanol. In one experiment a, the water was removed simply by evaporation, while nitrogen purging at 50 ml / min., 120 to 140 ml / min, and 250 ml / min, respectively, were used in experiments B, G and D. The reaction times required to form the last 7 ml of water in experiment A were 1, 3 hours, in experiment B 1.4 hours, in experiment C 0.8 hours and in experiment D 0.7 hours.

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series demonstrates the effect of quick removal of water as it is formed during the reaction.

Example 10

A series of continuous reactions were carried out in a 1 liter stainless steel reaction vessel equipped with a stirrer, Dean-Stark azeotrope, reflux condenser, and temperature recorder. In each experiment, an alcohol solution and either a solution of zinc naphthenate [(8% Zn) 1.3 g / 1000 g alcohol, corresponding to about 100 ppm] or zinc octoate [0.56 g / 1000 g alcohol, corresponding to about 100 ppm] were used continuously at a specified rate along with a specified rate of the aqueous KOH (4-5 %) was introduced into the central portion of the reaction vessel. A control experiment was carried out in which the zinc compound was omitted. The reactions were carried out under reflux conditions and some pressure. The water was continuously removed overhead and the reaction product was continuously withdrawn from the lower section of the reactor at a rate sufficient to achieve the predetermined residence time taking into account the feed rates of the reactants and the overhead removal of the water. After each reaction reached equilibrium, a sample of the reaction product was washed first with 25% H ₂ SO ^ and then with water and then dried. The sample was then hydrogenated using standard methods with a -Hickel / Kieseigur catalyst and then analyzed by gas chromatography to determine conversion and selectivity. Gas chromatographic analysis was not performed in three experiments and the conversion was determined based on the water collected. The conditions used in these experiments and the results obtained are given in Table III below.

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Table III

Supply!

search speed

Ur. alcohol

fast-W / h)

KOH

Temp. Pressure

because- ( ⁰ G)

Time

(Hours.)

Conversion kg / cm lung (psig) C / 0

Selectivity (wt%)

Product ** paraffins ***

high-boiling components

1-Δ 2-B 3-B 4-B 5-B 6-B 7-B 8-C 9-D

400 400 400 400 400 500 400 200 400

4.1 4.1 2.1

4.2 5.4 4.1 2.1 4.1

1,284 5.92 (70)

1,261 3.81 (40)

1,277 5.92 (70)

1,266 4.16 (45) 55-60 *

1 260 3.81 (40)

0.5 278 5.22 (60) 56 -

1 262 3.81 (40) 50-55 *

2 240 2.55 (22)

1,288 5.99 (71) 35-40 *

92.8
93.8
95.5

91.8
92.8

3.4

1.9
2.8

2.2
2.6

96.1 1.3

3.8 4.3 1.7

5.9 4.6

2.6

1-alkanols with 6 to

A - control, without zinc compound, mixed

Carbon atoms as starting material J)
B - Zinc naphthenate solution @ 5 ₎ (8 % Zn; and ALF03S »-G-6-10 alcohol starting material
C - zinc octoate and ALFOi ^ -O-6-IO alcohol starting material
D - zinc naphthenate solution (8% Zn) and mixture of essentially straight-chain 1-alkano-

len with 7, 9 and 11 carbon atoms (Santicizer 7-11) as starting material
* - calculated conversion, based on the formed water / water
** - alcohol with 12 to 20 carbon atoms

*** - Paraffins with 12 to 20 carbon atoms (some of which were due to their similar Boiling points cannot be easily separated from the product by customary distillation).

(J) to

As stated above, the organic zinc compounds do not constitute dehydrogenation catalysts under the reaction conditions This was demonstrated by a few simple dehydration experiments with 1-decanol and also with 2-octanol and 2-undecanol were carried out as expected would have been that the 2-alkanols are more easily dehydrated than the 1-alkanols.

Example 11

A sample of 1-decanol (ALIOIJ ^ -linear C-10 alcohol) was first applied to his by the usual colorimetric method using 2,4-dinitrophenylhydrazine The carbonyl content was analyzed and found to contain about 14 ppm carbonyl function. Then were used to determination the effectiveness of zinc naphthenate as a dehydrogenation catalyst 250 g of the 1-decanol and such an amount Zinc naphthenate, which provided 100 ppm of zinc metal based on the 1-decanol, in one with a magnetic stirrer and one Reaction flask equipped with a reflux condenser was introduced. The materials were sealed with a nitrogen blanket and then for about 2 hours at about 229 to 2 ^ 1 ° C boiled under reflux, which would lead to a dehydrogenation of the 1-decanol to carbonyl compounds, if the zinc naphthenate acts as a dehydrogenation catalyst. After this time a sample of the refluxed material was taken removed, the zinc removed and the carbonyl content analyzed as described above. The carbonyl content found of the refluxed 1-decanol was about 131 ppm. The results show that zinc naphthenate is not considered to be Dehydrogenation catalyst can be viewed.

Example 12

In terms of ease with the 2-alkanols how to

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expect v / ar who were dehydrated, similar attempts were made carried out as in Example 11 using a 2-octanol obtained from Eastman Chemicals. That as Starting material used was 2-octanol at the beginning analyzed for its carbonyl content and found to be about 2480 ppm. About 20 g of the 2-octanol and an amount of zinc naphthenate sufficient to provide about 100 ppm zinc metal based on the 2-octanol introduced into a reaction flask equipped with a magnetic stirrer and a reflux condenser. Subject of education With a nitrogen blanket over the materials, the materials were heated to reflux temperature (about 170 ° C.) and held at this temperature for about 5 1/2 hours. The refluxed 2-octanol was then analyzed and it was found to have about 2272 ppm carbonyl function contained. These experiments also show that the zinc compounds used according to the invention are not used as dehydrogenation catalysts act.

Example 1 3

A series of experiments similar to those described in Example 12 and 12 were carried out using 2-undecanol, a secondary alcohol with a boiling point similar to 1-decanol.

The 2-Unäecanol was first prepared by hydrogenating the obtained from Eastman Chemicals 2-Undecanons in a usual manner, followed by distillation, wherein the 2-undecanol in the form of a fraction was obtained which (was taken between 122 and 124- ⁰ C for about 7 ¹ ? % By weight of the total product). This 2-undecanol was analyzed and found to contain about 4-61 ppm carbonyl function.

A first sample of the 2-undecanol (25 g) '(* which had been prepared as above, together with a zinc metal sample of 100 ppm, based on the 2-undecanol, was sufficient.

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Pour adequate amount of zinc naphthenate into one with a magnetic stirrer reaction flask equipped with a reflux condenser. After creating a nitrogen protection atmosphere the materials were brought to reflux temperature (approx 2J0 to 233 ° C) and held at this temperature for about 1 hour. The refluxed 2-undecanol was then analyzed and found to be around 1519 Contained ppm carbonyl function.

The above procedure was followed with another 25 g sample of the 2-Undecanols repeated, but this time the boil was extended to 2 hours under reflux. The refluxed 2-indenol was analyzed and it became found that it contained about 777 ppm carbonyl function.

A third sample of the 2-undecanol (25 g) was refluxed for 2 hours as described above, this time however, no zinc compound was added. The refluxed 2-undecanol was analyzed and it became found that it contained about 860 ppm carbonyl function.

From the above experiments it can be seen that di-e according to the invention zinc compounds used do not act as dehydrogenation catalysts. Oddly enough, similar attempts have made that using zinc oxide as the zinc material, it was shown that zinc oxide was also not used as a dehydrogenation catalyst functions, although this is indicated in the prior art.

Although the zinc compounds which can be used according to the invention are not act as dehydrogenation catalysts, i.e. do not catalyze a unimolecular reaction with the formation of hydrogen, they are believed to act as cocatalysts in the oxidation of the alcohols involved in some way in the overall reaction mechanism occurs.

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Although the invention has been explained in more detail above with reference to specific embodiments, it is it is clear to the person skilled in the art that these can be changed and modified in many ways without thereby affecting the The scope of the present 'invention is left.

Patent claims:

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Claims (1)

Claims / Ύ? ¹ Process for the preparation of alcohols with higher ^ molecular weight by condensing at least one primary alkanol with lower molecular weight »which has a methylene group adjacent to the hydroxylated carbon atom, characterized in that the condensation in the liquid phase in the presence of an alkali catalyst and an organic zinc compound with simultaneous removal of the formed water is carried out using an alkali metal alcoholate or a precursor thereof which forms the alcoholate in the reaction system and a compound represented by the general formula as the organic zinc compound O -CO) ₀ Zn ₁ (I) C. 0 HR "(R" -CG = C-0) _o Zn or (II) (E "'- SOj) ₂ Zn (IH) wherein R ¹ , R "and R '" each independently represent saturated or unsaturated, cyclic or acyclic, branched-chain or straight-chain hydrocarbon groups. 2. The method according to claim 1, characterized in that an organic zinc compound of the formula given in claim 1 is used in which R ¹ 1 to 30 carbon atoms, R "1 to 10 carbon atoms and R" ^{1 have} 6 to 54 carbon atoms. 3. The method according to claim 1 and / or 2, characterized in that a zinc compound of the formula I is used in which R ^{1 has} 1 to 30 carbon atoms. 409843/1097 - 50 - 4-. Process according to claim 3, characterized in that zinc compound, zinc benzoate, zinc gallate, Zinc naphthenate, zinc oleate or zinc laurate is used. 5. The method according to claim 4, characterized in that that zinc octoate or zinc naphthenate is used as the zinc compound. 6. The method according to claim 1 and / or 2, characterized in that a zinc compound of the formula II is used in which the substituents R "are each independently of the other Have 1 to 10 carbon atoms. 7. The method according to claim 6, characterized in that zinc acetylacetonate is used as the zinc compound. 8. The method according to claim 1 and / or 2, characterized in that a zinc compound of the formula III is used, wherein R " ^{1 has} 6 to ^ A carbon atoms. 9. The method according to claim 8, characterized in that the zinc compound zinc (Cp-Op ^ -aikyl) benzenesulfonate, zinc di- (C ₂ -G ₂ ^ -alkyl) benzenesulfonate, zinc (Cg-C. ^) -alkylenesulfonate, zinc (Cg-C- ^ ₀ ) -alkylsulfonate, zinc-p-toluenesulfonate, zinc naphthaline-ß-sulfonate or zincbenzenesulfonate is used. 10. The method according to at least one of claims 1 to 9 »characterized in that the alkali catalyst is sodium hydroxide, Potassium hydro: cyd, sodium alcoholate, potassium alcoholate, metallic sodium or metallic potassium is used. 11. The method according to claim 10, characterized in that the alkali catalyst in an amount corresponding to about 0.1 to about 4 moles of alkali metal is used per mole of the primary alkanol. A09843 / 1097 12. The method according to at least one of claims 1 to 11, characterized in that the zinc compound in one is used to deliver at least 10 ppm zinc metal based on the primary alkanol. 13. The method according to at least one of claims 1 to 12, characterized in that the primary alkanol with lower Molecular weight an alkanol of the general formula is used R-CH ₂ -CH ₂ OH wherein E is a straight or branched chain alkyl group with 2 to 28 carbon atoms means. Process according to Claim 13 »characterized in that a mixture of alkanols is used as the primary alkanol will. 15. The method according to claim 13 and / or 14, characterized shows that the primary alkanol is a mixture of Gg-G ^ o " Alkanols is used. 16. The method according to claim 13 and / or 14, characterized in that a mixture of ^ <] ß ~ ^ 20 alkanols is used as the primary alkanol. 409843 / 1-097