JPH03279336A - Production of branched dimerized alcohol - Google Patents

Abstract

PURPOSE:To perform the reaction in the presence of a solvent soluble in a primary alcohol but insoluble in water under a condition that both the solvents and the produced water are distilled outside, when the primary alcohol or its mixture with any other compound are subjected to a dehydrative condensation reaction to provide a branched dimerized alcohol. CONSTITUTION:When a compound of formula I (R<1> is straight chain or branched chain 1-6C alkyl, alkenyl) and a compound of formula II (R<2> is straight chain or branched 1-22C alkyl, alkenyl, cycloalkyl, phenylalkyl) are condensed with each other in the presence of an alkaline substance (e.g. KOH) and, if necessary, a dehydrogenation catalyst (e.g. Pt-C) to provide the subject substance, the reaction is carried out in the presence of a solvent soluble in a primary alcohol and slightly soluble in water at 150-280 deg.C while refluxing the alcohols and the solvent and distilling the produced water outside. The solvent is preferably a hydrocarbon (e.g. benzene) having a boiling point of 75-200 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field] The present invention relates to a process for dehydrating and condensing primary alcohols or mixtures thereof to obtain branched trimerized alcohols. The branched dimerized alcohol produced by the present invention is a substance useful directly or as an intermediate raw material for surfactants, textile oils, softeners, cosmetics, etc.

[Conventional technology]

Conventionally, when primary alcohol is dehydrated and condensed in the presence of an alkaline substance or in the presence of an alkaline substance and a dehydrogenation catalyst, one molecule of branched dimerized alcohol and one molecule of water are produced from two molecules of raw alcohol. is widely known and is called the Guerbet reaction, and is expressed by the following reaction formula.

R In this reaction, studies have been made to optimize the type of dehydrogenation catalyst, type of alkaline substance, and reaction conditions for the purpose of increasing the reaction rate, improving the quality of the alcohol produced, or suppressing side reactions, and many improvement proposals have been made (Japanese Patent Publication No. 45 -5521
, Special Publication No. 51-17525, Special Publication No. 61-59612,
Japanese Patent Publication No. 61-6806, etc.), and these methods are widely used for industrial production.

[Problem to be solved by the invention]

However, when at least one of the raw material primary alcohols has carbon atoms of 8 or less, particularly 6 or less, the conventional technique is not a satisfactory method. That is, the reaction is a dehydration reaction, and it is common to proceed with the reaction while removing water generated during the reaction from the system. When the boiling point of the raw alcohol and the reaction temperature are different, dehydration is performed under increased pressure or reduced pressure), or a method is used in which reaction water is removed from the system while blowing inert gas such as nitrogen gas.

However, in this method, when the number of carbon atoms in the raw material primary alcohol is 8 or less, the reaction product water is dissolved in the refluxing raw material alcohol, so the reaction product water cannot be removed from the reaction system, and as a result, the reaction product water cannot be removed from the reaction system. A phenomenon occurs in which the process does not progress. For this reason, complicated operations are required, such as distilling the raw alcohol containing reaction product water out of the system, separating and purifying the water and raw primary alcohol by rectification, and reusing only the raw primary alcohol. Met. In addition, if raw alcohol is continuously distilled, if the raw alcohol is not continuously replenished to match the distilled amount, the yield will drop significantly or a tri-membered alcohol with a constant composition will not be obtained. Complicated operations such as replenishing alcohol were required. If this produced water can be removed efficiently without using a rectification column, it will be possible to shorten reaction time, simplify reaction equipment, reduce nitrogenity, and reduce the production cost of tri-membered alcohols. becomes.

[Means to solve the problem]

Therefore, the present inventors have proposed that when producing a three-membered alcohol by a Guerbet reaction using a highly water-soluble alcohol, that is, an alcohol having 8 or less carbon atoms, especially 6 or less carbon atoms, a known alkaline substance or an alkaline substance is used. In the presence of a dehydrogenation catalyst, add a poorly water-soluble solvent that is soluble in the water-soluble raw material primary alcohol, or a poorly water-soluble solvent that is soluble in the water-soluble raw material alcohol and is azeotropic with water to the reaction system. However, they discovered that the target Guerbet alcohol could be produced in good yield by distilling the solvent and the produced water out of the reaction system, and completed the present invention.

According to the present invention, a Guerbet reaction is carried out using a highly water-soluble alconope, that is, an alcohol having 8 or less carbon atoms, particularly 6 or less, or a mixed alcohol containing an alcohol having 8 or less carbon atoms, to produce a branched dimerized alcohol. When manufacturing,
In the presence of a known alkaline substance or in the presence of an alkaline substance and a dehydrogenation catalyst, a solvent that is soluble in the raw material primary alcohol and poorly soluble in water is added to the reaction system, and under atmospheric pressure or pressurization,
The raw alcohol and solvent are refluxed at a temperature of 150 to 280°C, the water produced by the reaction is continuously removed from the reaction system together with the solvent, and the distilled raw alcohol and solvent are returned to the reaction system to carry out the Guerbet reaction. By doing so, a branched trimerized alcohol is produced.

That is, the present invention is based on the general formula CI) R'-C)la-CHaOHCI) [wherein R1 represents a group selected from the group consisting of a linear or branched alkyl group having 1 to 6 carbon atoms and an alkenyl group] ] A primary alcohol represented by the general formula (II) R''-CHz-CH2-OHCII and a group selected from the group consisting of phenylalkyl groups] and a primary alcohol represented by In this branching process, the reaction is carried out in the presence of a solvent that is soluble in the primary alcohol and is sparingly soluble in water, under conditions such that the solvent and the water produced are distilled out of the reaction system. This invention relates to a method for producing dimerized alcohol.

In the present invention, the primary alcohol represented by the general formula CI) includes propatool, butanol, pentano-/
L/, hexanol, octano-)pedecanol, dodecanol, tetradecanol, hexadecanol, octadecanol, eicosanopeoctadecenol, etc., and the primary alcohol represented by the general formula CIII includes propanol butanol. , pentanol, hexanonopeoctanol, decanol, dodecanonobetetradecanol, hexadecanol, octadecanonopeicosanonopeoctadecenonopecyclohexylmethanope2-cyclohexylethanol, etc. It is.

The poorly soluble solvent used in the present invention is preferably a hydrocarbon compound having a boiling point of 75 to 200°C at normal pressure. It is preferable to select a solvent that is azeotropic with water or a solvent that has a boiling point close to that of the raw alcohol (in the case of a mixed alcohol, the alcohol with the lowest boiling point).

Specific examples of the solvent used in the present invention include aromatic hydrocarbon compounds such as benzene, xylene, and toluene, or aliphatic hydrocarbon compounds such as octane and decane, which are stable against alkalis and react with the raw material alcohol. Examples include solvents that do not cause Moreover, these hydrocarbon compounds may be used in a mixture of two or more types.

Examples of the alkaline substance used in the present invention include sodium metal, sodium alcoholade, sodium hydroxide, sodium carbonate, sodium amide, potassium metal, potassium amide, potassium hydroxide, potassium carbonate, potassium phosphate, and the like. Among them, potassium hydroxide is preferred.

The amount of alkaline catalyst to be used can be added in an appropriate weight ratio to the primary alcohol used, but if too much is used, alkali melting will occur and the raw material primary alcohol will be converted to the corresponding fatty acid soap. Since a decrease in yield occurs, the amount is generally the same as in the conventional method, i.e.
It is used in an amount of 10% by weight, preferably in the range of 1 to 5% by weight.

Further, the dehydrogenation catalyst used in the present invention is not particularly limited, and may be any catalyst that has a suitable dehydrogenation ability, such as copper chromite, copper powder, copper zinc, zinc oxide, zinc chromite, stabilized Nickel, alumina silicate, nickel supported on activated carbon, platinum, palladium, ruthenium, rhodium, or Raney alloys (nickel, chromium, copper, etc.) can be used.

The amount of dehydrogenation catalyst used is 0.0 of the raw material primary alcohol.
02 to 1.0% by weight, preferably 0.005 to 0.2% by weight. The amount of dehydrogenation catalyst used may be greater than this range, but no improvement in effectiveness can be expected even if it is added in excess of this range. Moreover, if it is less than this range, the reaction rate will decrease.

When a dehydrogenation catalyst is not used, generally 250 to 280
It is necessary to carry out the reaction for 2 to 3 hours or more under pressure at a temperature of .degree.

If a raw alcohol with carbon number 8 or less is used, the reaction pressure will be 40 kg/cm or more in the case of 1-butanol, for example.On the other hand, if a dehydrogenation catalyst is used, it will take less time to complete the reaction within the same time. 200-220°C is sufficient;
The reaction pressure at this time is 10 to 20 kg/Cm''. Therefore, equipment costs can be reduced, which is advantageous for industrial implementation.

〔Example〕

Next, the present invention will be specifically explained using Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1 1,81 SO3316 with stirrer, thermometer, nitrogen blowing tube and condenser and separator to separate produced water
244 g (3.3 mol) of n-butanol in a reactor made of
707 g (3.3 mol) of n-myristyl alcohol,
10 g of granular potassium hydroxide, copper-nickel catalyst supported on alumina (catalyst shown in Japanese Patent Publication No. 61-59612, where the weight ratio of copper and nickel is 80:20 and the content of copper and nickel metals in the total catalyst is 40% by weight) )0.2g,)Luene8
0 g was charged, and the temperature was raised while bubbling nitrogen gas into the system at 301/hr.

The time when the temperature reaches 220°C is defined as the reaction start time.

The reaction pressure is approximately 6.8 kg/cm when the temperature reaches 220°C.
”. At this time, while drawing out the reaction water from the system,
Continue the reaction at 0°C. As the reaction progresses, the pressure inside the reaction vessel decreases (reaction temperature remains constant) and eventually reaches normal pressure. The reaction was stopped 10 hours after the start of the reaction, and the mixture was cooled. The reaction solution was filtered to remove the catalyst and the precipitated carboxylic acid potassium salt, and then washed several times with warm water to remove the dissolved carboxylic acid potassium salt and unreacted n-butanol. This water-washed filtrate was heated to 100°C at 100 mmHg.
The toluene used as a reaction product water separation solvent was distilled off to obtain 839.6 g of oil. Gas-liquid chromatography analysis revealed the following composition. Tetradecanol-112, 27%, 2-ethylhexanol-
19.50%, 2-ethylhexadecanol-1 and 2
-Butyltetradecanol-139.47%, 2-dodecylhexadecanol-133J1%, others 5.45
%.

The yield of branched trimerized alcohol based on n-butanol and n-myristyl alcohol was 79.7%.

Comparative Example 1 A reaction was carried out under the same conditions as in Example 1 except that toluene was not used as a solvent.

The reaction was carried out for 10 hours, and the same treatment as in Example 1 was performed.

Oil content: 694.7 g, composition: tetradecanol-19
4,63%, 2-ethylhexanol-10,63%,
The contents were 2-ethylhexadecanol-1 and 2-butyltetradecanol-12.60%, 2-dodecylhexadecanol-11.97%, and others 0.16%. n-
The yield of branched trimerized alcohol based on butanol and n-myristyl alcohol was 2.7%.

Example 2 Using the same equipment as in Example 1, n-heptatool 333
．． 7g (3.3 mol) and hexadecanol-170
0 g (3.3 mol), 80 g of 0-xylene, 10 g of granular potassium hydroxide, and 0.2 g of a commercially available copper-chromium catalyst were charged, and a reaction was carried out. The time when the temperature reached 220°C was defined as the reaction start time. The reaction pressure at this time was 2-Okg/(
mz, which decreased as the reaction progressed and finally reached normal pressure. The reaction was completed after a reaction time of 8 hours, and the same treatment as in Example 1 was performed. Unreacted n that could not be removed by washing with water
- Heptatool was removed at the same time as the 0-xylene removal process.

The amount of oil obtained was 939.9 g, and the composition was 14.1% tetradecanol and 1% 2-butyl octanoyl.
11.1%, 2-butylhexadecanol-1 and 2-
Hebutyltetradecanol-142.0%, 2-dodecylhexadecanol-133.3%, and others 9.5%. The yield of branched trimerized alcohol based on n-heptatool and hexadecanol-1 was 85.6%.

Example 3 Using the same equipment as in Example 1, 244 g of n-butanol
1,707 g of tetradecanol, 80 g of toluene, and 10 g of granular potassium hydroxide were charged, and a reaction was carried out. The time when the reaction temperature reaches 210°C is the reaction start time,
The reaction pressure at this time was 9.5 kg/cm2. Raise the reaction temperature while maintaining the reaction pressure of 9.5 kg/cm'2.
The temperature was set to 40°C. Next, the reaction is continued while maintaining the reaction temperature at 240°C. As the reaction progressed, the reaction pressure decreased and finally reached normal pressure. The reaction was completed after a reaction time of 40 hours, and the same treatment as in Example 1 was performed. The amount of oil obtained is 8
It weighs 30.8 g and has a composition of tetradecanol-116.
, 6%, 2-ethylhexanol-19.5%, 2-ethylhexadecanol-1 and 2-butyltetradecanol-139.2%, 2-dodecylhexadecanol-
129.8%, others 5.0%. The yield of branched trimerized alcohol based on n-butanol and tetradecanol-1 was 75.2%.

Example 4 Using the same equipment as Example 1, 960 g of n-butanol
(13,0 mol), 10 g of granular potassium hydroxide, copper-nickel catalyst supported on alumina (same as Example 1) 0
．． Prepare 2g and 80g of toluene, and add 30r of nitrogen gas.
nf! /hr to raise the temperature while bubbling inside the system.

The time when the temperature reaches 200°C is defined as the reaction start time. 200
The reaction pressure at the time the temperature reached 10.5 kg/cm2 was reached. At this time, the reaction pressure is kept constant while the reaction water is extracted from the system, and as the reaction progresses, the reaction temperature rises.
Raise the temperature to 20°C. As the reaction progresses further, the pressure inside the reaction tank decreases (the reaction temperature remains constant), and the final weight is 1.1 kg/
Become am2. The reaction was stopped 15 hours after the start of the reaction, and the mixture was cooled. The reaction solution was filtered to remove the catalyst and precipitated carboxylic acid potassium salt, and then washed several times with warm water.
Dissolved carboxylic acid potassium salt and unreacted butanol were removed. This water-washed filtrate was heated to 100° C. at 100 mmHg, and toluene used as a reaction product water separation solvent was distilled off to obtain 708.3 g of oil. Gas-liquid chromatography analysis revealed the following composition. 2
-Ethylhexanol-193.82%, others 6.1
8%, the yield of branched trimerized alcohol based on n-butanol was 78.8%.

Claims (1)

[Claims] 1 General formula [I] R^1-CH_2-CH_2-OH [I] [In the formula, R^1 consists of a linear or branched alkyl group having 1 to 6 carbon atoms and an alkenyl group Represents a group selected from the group] A primary alcohol represented by the general formula [II] R^2-CH_2-CH_2-OH [II] [In the formula, R^2 is a linear or branched chain with 1 carbon number ~ represents a group selected from the group consisting of an alkyl group, an alkenyl group, a cycloalkyl group, and a phenylalkyl group] in the presence of an alkaline substance or in the presence of an alkaline substance and a dehydrogenation catalyst. Conditions for producing a branched dimerized alcohol by condensation in the presence of a solvent that is soluble in the primary alcohol and poorly soluble in water, and that the solvent and produced water are distilled out of the reaction system. 1. A method for producing a branched dimerized alcohol, the method comprising carrying out a reaction at