JPS6357408B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing higher α-olefins using higher internal olefins as starting materials.

Higher α-olefins are important substances as raw materials for producing higher linear primary alcohols, amines, aldehydes, or fatty acids, and have been produced by polymerization of ethylene, decomposition of paraffin, etc. However, high-grade α-
Olefins are a mixture of olefins with different carbon chain lengths, and it is extremely difficult to obtain pure α-olefins having 20 or more carbon atoms using the above method.
Among the linear primary alcohols easily derived from α-olefin, 1-triacontanol has recently attracted attention as a plant growth regulator, as well as linear fatty acids, aldehydes, and amines that have physiological activity. Therefore, it is desired to develop a method for synthesizing these pure compounds.

However, one method for synthesizing pure α-olefins uses acids, alkalis, halogen atoms, boron, aluminum, zinc, etc. to synthesize olefins with double bonds inside the carbon chain (hereinafter referred to as internal olefins). Methods are known to shift the position of a double bond, but this method can only shift the double bond by a few carbon atoms; for example, if the double bond is moved across a chain of 10 or more carbons It has been extremely difficult to transfer bonds with good yield.

Also, the general formula CH ₃ (CH ₂ ) _n CH=CH (CH ₂ ) _o CH ₃
Among the internal olefins expressed as m+n≦10
_The lower _internal olefin, which _{is o+3} ]
After converting to ₃ B, a lower olefin is added to perform alkylation, resulting in an α-olefin in which the double bond has moved to the chain end, that is, CH ₃ (CH ₂ ) _n+o+1 CH=
It has been reported that CH ₂ can be isomerized (Brown, HC et al. J. Am. CHem. Soc., 81, page
6434-6437 (1959)).

However, no example has yet been published in which the above reaction is carried out for higher internal olefins (m+n≧16 for the above-mentioned internal olefins).

The present invention is based on the general formula CH ₃ (CH ₂ ) _n CH=CH (CH ₂ ) _o CH ₃ () (where m and n are integers, 30≧m+n≧16
It is. ) using high-grade internal olefin as raw material,
A secondary alkylborane is synthesized and further reacted with an α-olefin represented by the general formula CH ₃ (CH ₂ ) _p CH=CH ₂ ( ) (in the formula, p≦17) to produce a trialkylborane. i and j are 0 or positive integers, i+j=3. ) and heated to produce trinormal alkylborane ([CH ₃ (CH ₂ ) _p+2 ] _i B [(CH ₂ ) _n+o+3 CH ₃ ] _j , i and j are the same as above.) A method of isomerizing the trinormal alkyl borane obtained by this isomerization with an α-olefin having 10 or less carbon atoms to obtain the general formula CH ₃ (CH ₂ ) _n+o+1 CH=CH ₂ An object of the present invention is to provide a method for producing a higher linear α-olefin represented by (namely, a method for isomerizing olefin).

The present invention will be explained in detail below.

The higher internal olefin used as a raw material in the present invention has the general formula CH ₃ (CH ₂ ) _n CH=CH (CH ₂ ) _o CH ₃ () (where m and n are integers, 30≧m+n≧16
It is. ) and may be obtained by a known method.
For example, higher internal olefins represented by nm in the formula can be easily synthesized by the following method.

That is, as shown in Example 1 below, 15-
Triaconten CH ₃ (CH ₂ ) ₁₃ CH=CH
(CH ₂ ) ₁₃ CH ₁₃ can be obtained. The above-mentioned 15-triacontanol is a new substance with a melting point of 51 to 53°C and an M ⁺ 420 by mass spectrometry, and is 1-triacontanol _CH3 , which is useful as a plant growth regulator.
(CH ₂ ) ₂₉ OH is a suitable raw material. The olefin () used in the present invention can be used alone or in combination depending on the purpose.

In the alkylborane synthesis using the above-mentioned olefin () and borane, the reaction is carried out at a molar ratio of olefin () and borane of 2 or less, preferably 1.5 or less, and more preferably 1.2 to 0.8. In this reaction, borane is usually used in the form of BH ₃ or B ₂ H ₆ dissolved in, for example, tetrahydrofuran, but there is no particular limitation as long as the system generates BH ₃ within the reaction system. Preferred reaction solvents include diethylene glycol dimethyl ether and triethylene glycol dimethyl ether, but ether solvents can also be used in addition to these. Although reaction conditions can be arbitrarily selected, the reaction temperature is preferably 0 to 60°C, particularly preferably room temperature to 40°C, and the reaction time is 1 to 5 hours.

Next, in the reaction between an alkylborane and an olefin (), the molar ratio of (olefin () + olefin ())/borane is preferably 3, but is not particularly limited to this.

Olefin () used in the present invention
Any olefin having 20 carbon atoms or less can be used, but the trialkylborane after isomerization is subjected to an exchange reaction or a substitution reaction to form a higher linear α-
When producing olefin, other amines, aldehydes, ketones, etc. as a target product, it is desirable to select an olefin () that can be easily separated from the target product. Furthermore, for the purpose of isomerization, it is better to use a sterically bulkier olefin (). Olefins () that meet these conditions include 1-butene, isobutene,
2,3-dimethyl-butene-1,1-hexene,
1-octene, 1-decene, 1-dodecene, 1-
Examples include single compounds of hexadecene, 1-octadecene and styrene, or mixtures thereof, if necessary. The above trialkylborane synthesis conditions are not particularly limited, but the reaction temperature is usually room temperature to 100°C, preferably
The temperature may be 40 to 60°C and the reaction time may be about 1 to 5 hours.

The isomerization of the trialkylborane thus obtained is usually carried out at a temperature of 150°C while the above synthesis reaction is still being carried out.
The reaction is completed by increasing the temperature to ˜250° C. and maintaining the reaction at that temperature for 5 to 72 hours.

When an α-olefin having 10 or fewer carbon atoms, such as 1-hexene, is added to the isomerized trinormal alkyl borane and heated under reflux, the general formula CH ₃ (CH ₂ ) is obtained.
A higher linear α-olefin represented by _n+o+1 CH=CH ₂ can be obtained.

As is clear from the above explanation, according to the present invention, it is possible to easily produce a single high-grade linear α-olefin in high yield, which could only be easily produced as a mixture in the past. The above contribution is significant.

The present invention will be specifically explained below by way of examples.

Example 1 Production of 1-triacontene (1) Production of 15-triacontene A flask equipped with a reflux condenser was purged with argon, and the entire system was then placed under an argon atmosphere until the reaction was completed. A trichloroethylene solution (22 ml) of 1-hexadecene (30 mmol) and tungsten hexachloride (1.4 mmol) and a trichloroethylene solution (2 ml) of acetonitrile (0.96 mmol) and tetrabutyltin (0.96 mmol) were respectively injected into the above flask with a syringe. The mixture was heated to 80°C and stirred for 5 hours. The reaction solution was put into a column packed with alumina, the column was washed with petroleum ether, leaving only the tungsten compound in the column, the solvent was evaporated from the effluent, and the residue was distilled under reduced pressure to obtain 172-174
A fraction of °C/0.015 Torr was collected and recrystallized to obtain white crystals. Melting point 51-53℃, M ⁺ 420 by mass spectrometry spectrum, infrared absorption band 960 cm ^-1 (trans
CHR = identified as CH out-of-plane bending vibration of CHR), nuclear magnetic resonance absorption (δ) 5.24 (vinyl proton), 1.92 (allyl proton), 1.24 (methylene proton) and
0.87ppm (methyl proton).

This crystal was ozonized to ozonide, and decomposed with sodium borohydride to obtain 1-pentadecanol. From the above results, this crystal is 15-
It was confirmed that it was Triaconten.

(2) Isomerization of 15-triacone ) and a separately prepared tetrahydrofuran solution (50 ml) of diborane (12 mmol) were added to this flask and stirred at room temperature for 2 hours, then 1-hexene (20 mmol) was added thereto and the temperature was raised to 50 °C. The mixture was stirred for 2 hours, and the temperature was further raised to 160°C, and heating was continued for 16 hours to reflux. After cooling this to room temperature, 1
- Add hexene (0.1 mmol) and make 160 again
The flask was immersed in an oil bath at 0.degree. C. and refluxed for 2 hours.
This reaction solution was distilled under reduced pressure to remove 1-hexene, the solvent, and trihexylborane (a substance produced by the exchange reaction), and a fraction at 160 to 200°C/0.1 Torr was collected to obtain a triacontene mixture. White crystals were obtained by recrystallizing this from ligroin several times. Melting point 61.5-62.5℃, from mass spectrum
M ⁺ 420, nuclear magnetic resonance spectra (δ) 0.9 (methyl proton), 1.27 (methylene proton), 1.94 (allyl proton), 4.76~5.22 ( _CH2 =) and 5.4~
It was 6.2 ppm (=CH-). From these results, it was confirmed that the product was 1-triacontene. That is, it was confirmed that 15-triacontene was isomerized to 1-triacontene.

Example 2 (1) Production of triacontene mixture Diethylene glycol dimethyl ether (200 ml) and 15-triacontene (10 mmol) prepared in Example 1 were placed in a flask equipped with a reflux condenser on top connected to an absorption bottle containing a mercury bubbler and acetone. A separately prepared solution of diborane (12 mmol) in tetrahydrofuran (50 ml) was added thereto, and the mixture was stirred at 50°C for 2 hours.The temperature was further raised to 160°C, and heating was continued for 16 hours to reflux. After cooling this to room temperature, 1-hexene (30 mmol) was added and again
It was immersed in an oil solution at 160°C and refluxed for 2 hours. This reaction solution was distilled under reduced pressure to remove 1-hexene, solvent and trihexylborane, and the mixture was distilled at 155-200℃/0.1Torr.
The fractions were collected to obtain a triacontene mixture.

The product was determined by gas chromatography to contain 17% 1-triacontene and 15-triacontene.
It was a triacontene mixture containing 26% of other triacontene and 48% of other triacontene.

(2) Production of 1-triacontene from a triacontene mixture In a flask equipped with a reflux condenser on top connected to an absorption bottle containing a mercury bubbler and acetone, add diethylene glycol dimethyl ether (20 ml) and a triacontene mixture (1-triacontene 17%). , 15 - tria content 26%, other tria content 48
%, 1 mmol) and a separately prepared solution of diborane (1.2 mmol) in tetrahydrofuran (5
ml) and stirred at 50°C for 2 hours, then a solution of 1-hexadecene (2 mmol) in diethylene glycol dimethyl ether (10 ml) was added, the temperature was raised to 60°C, and after stirring for 3 hours, the temperature was further increased. The temperature was increased to 160°C, and the mixture was heated under reflux for 12 hours.

Next, a transalkylation reaction was carried out according to Example 1 (2), and the reaction solution was distilled under reduced pressure to remove 1-hexene, the solvent, and trihexylborane, and the mixture was heated at 160 to 200°C/
A fraction of 0.1Torr was collected. As a result of measuring this by gas chromatography, it was confirmed that it contained 76% 1-triacontene.

Claims (1)

[Claims] 1 General formula CH ₃ (CH ₂ ) _n CH=CH (CH ₂ ) _o CH ₃ () (wherein m and n are integers, and 30≧m+
n≧16. ) The reaction product of olefin () represented by borane and olefin () represented by the general formula CH ₃ (CH ₂ ) _p CH=CH ₂ () (in the formula, p is an integer satisfying p≦17) is further reacted to form the general formula (In the formula, i and j are 0 or positive integers, and i+j=3). After producing a trialkylborane represented by
The general formula CH ₃ (CH ₂ ) _n+o+1 CH=CH ₂ (in the formula, m and n represent the same meanings as above), characterized in that the alkylation is carried out by adding 10 or less α-olefins. ) A method for producing a high-grade α-olefin. 2 Olefin () has the formula CH ₃ (CH ₂ ) _n CH=CH(CH ₂ ) _o CH ₃ (where m and n are equal integers, and 30≧m
+n≧16. ) The method according to claim 1, which is represented by: 3. The method according to claim 1, wherein the olefin () is 15-triacontene. 4 Olefin () is 1-butene, isobutene, 2,3-dimethylbutene-1,1-hexene, 1-octene, 1-decene, 1-dodecene,
4. A method according to any one of claims 1 to 3, wherein the material is selected from the group consisting of 1-hexadecene, 1-octadecene and styrene or mixtures thereof.