JPS59200778A - Manufacture of 1-triacontanol - Google Patents

Abstract

PURPOSE:To manufacture safely 1-triacontanol in a high yield by subjecting long-chain dicarboxylic monoester and long-chain carboxylic acid to electrolytic condensation and by reducing the resulting triacontanoic ester with a specified reducing agent. CONSTITUTION:Long-chain dicarboxylic acid represented by a general formula HOOC(CH2)mCOOH (where m is an integer of 12-20) is reacted with alcohol represented by a general formula ROH (where R is alkyl) to prepare long-chain dicarboxylic monoester represented by a general formula HOOC(CH2)mCOOR (where m is an integer of 12-20, and R is alkyl). This monoester and long-chain carboxylic acid represented by a general formula CH3(CH2)nCOOH (where n is an integer of 8-16) are subjected to crossed Kolbe electrolytic condensation in an alcohol solvent such as methanol to prepare triacontanoic ester represented by a general formula CH3(CH2)n(CH2)mCOOR. The amount (mole) of the carboxylic acid used is 0.5-2 times the amount of the monoester. The triacontanoic ester is reduced with a composite reducing agent. 1-Triacontanol represented by a general formula CH3(CH2)28CH2OH is safely manufactured in a high yield.

Description

[Detailed description of the invention] The present invention relates to a method for producing 1-triacontanol.

1-1-Liacontanol is an extremely valuable compound that significantly increases the yield of agricultural crops in the presence of trace amounts of metal ions such as calcium and lanthanum, and is a compound that is expected to be an innovative plant growth promoter. be. Conventionally, 1
- As a method for producing triacontanol, for example, the method of Gibson et al. [J.

Ory, chem, 46.1821 (1981); T
etrahedron Lett,, 1982°15
7] and the method described in Japanese Unexamined Patent Publication No. 57-181027 are known. However, all of the conventionally known methods have the following problems: the yield of the target l-triacontanol is low, the reagents used are expensive, the reaction selectivity is poor and there are many by-products, and there are many reaction steps. This method has drawbacks such as complicated reaction operations, and is an extremely disadvantageous method from an industrial perspective. That is, in the former method, as shown in reaction formula A below, 1-hexadecene is metathesized to obtain 15-triacontin, and then 15-triacontin is converted into the corresponding vl-containing metal corrosion compound by hydrozirconation. This is followed by oxidation with tert-butyl hydroperoxide to obtain 1-triacontanol.

Reaction formula A CH3(CH2)13CH= CH2→CF1t3(C
I(2)18CH= CH(CH2)18C'H.

Cp2ZrHCI CH8(CH2)13CH2-CH2(c) (2 pieces,
CH,, -C%-ZrCpf, 1 liter (E Cl0
(CH2)28CH20H In the method shown in the above reaction formula A, a large amount of byproducts are produced in the metathesis stage, and the desired 1-triacontanol can only be obtained in a low yield of about 39%. Furthermore, the reagents used in the hydrozirconation and oxidation steps are expensive, and furthermore, large-scale reactions have fatal drawbacks such as a high risk of explosion and fire.

In addition, in the latter method, as shown in Reaction Formula B below, cyclododecanone and morpholine are first reacted to obtain 1-morpholino-1-cyclododecene, and then stenteric acid chloride is reacted with this to obtain 1-morpholino-1-cyclododecene under acidic conditions. The resulting diketone is reacted with an alkali metal hydroxide and diethylene glycol, and then with hydrazine hydrate, acidified to give melisic acid, and finally, this is reduced with a borane/methyl sulfide complex to give 1-triazine. This is how to obtain contanol.

Reaction formula B K OH ■N I(!N H2・H2O ■I('l-) In the method shown in reaction formula B above, the reaction steps are extremely long, and the yield of the target product, 1-triacontanol, is approximately 2
It is extremely low at 9%, the reaction operation is complicated, and the reaction reagents used are expensive, making this method unsuitable for industrial use.

The present inventors have conducted intensive research to develop an industrially advantageous manufacturing method for 1-triacontanol under the current circumstances, and have finally completed the present invention.

According to the method of the present invention, the reaction steps are short, the reaction operation is simple, and the desired yield of 1-triacontanol is 50% or more, in some cases 60% or more, under mild reaction conditions. Moreover, it can be produced with high purity of 99% or more. Furthermore, the present invention does not require the use of special reaction reagents, and all of the starting materials used are readily available and inexpensive compounds. Therefore, the method of the present invention is industrially extremely advantageous.

According to the method of the present invention, first, the general formula %formula% [In the formula, R represents an alkyl group, and m represents an integer of 12 to 20.

A long-chain dicarboxylic acid monoester represented by the formula % and a long-chain carboxylic acid represented by the general formula % (21 [in the formula, n represents an integer of 8 to 16]) were mixed in an alcohol solution with a crossed Kolbe trowel. By electrolytic condensation, a triacontanoic acid ester represented by the general formula % (31 [in the formula, R, , m and n are the same as above, but the sum of m and n is 28] was obtained, and then this 1-) Reacontanol represented by the formula 0 formula %) is produced by reducing .

The long-chain dicarboxylic acid monoester ill and the long-chain carboxylic acid (2) used as starting materials in the present invention are both easily available known compounds. Examples of the alkyl group represented by R in the above general formula fil include methyl group, ethyl group, n-propyl group, inpropyl group, n-butyl group,
Examples include alkyl groups having 1 to 6 carbon atoms such as tert-butyl group, n-pentyl group, and n-hexyl group, preferably methyl group or ethyl group. Specifically, the long-chain dicarboxylic acid monoester is dodecane-1,12-
Monomethyl dicarboxylate, monoethyl dodecane-1,12-dicarboxylate, monomethyl tabucate, monoethyl tabucate, monomethyl hexadecane-1,16-dicarboxylate, monoethyl hexadecane-1,16-dicarboxylate, octadecane-1,18-dicarboxylic acid Monomethyl, monoethyl octadecane-1,18-dicarboxylate, mono-n- octadecane-1,18-dicarboxylate
Propyl, monoisopropyl octadecane-1,18-dicarboxylate, mono-n-butyl octadecane-1,18-dicarboxylate, mono-n-pentyl octadecane-1,18-dicarboxylate, mono-n-octadecane-1,18-dicarboxylate Examples include hexyl, monomethyl eicosane-1,20-dicarboxylate, and monoethyl eicosane-1,20-dicarboxylate. Further, specific examples of long-chain carboxylic acids include capric acid, lauric acid, myristic acid, palmitic acid, and stearic acid.

The ratio of the long-chain dicarboxylic acid monoester to the long-chain carboxylic acid is not particularly limited and can be appropriately selected within a wide range, but the ratio of the latter to the former is usually at least 0.5@mol, preferably It is preferable to use about equimolar to twice the molar amount. In the electrolytic synthesis of the present invention, the long-chain dicarboxylic acid monoester and long-chain carboxylic acid as raw materials can be carried out batchwise for a certain period of time (until they run out), or continuously so that the raw material concentration is maintained at a constant concentration. You may do so.

In the present invention, alcohol used as a solvent may be used such as methanol, ethanol, impropatol, or a mixture thereof. These alcohols may contain some calm water. The concentration of water is usually 5% or less, preferably about 0.15 to 8.5%. The concentrations of the long-chain dicarboxylic acid monoester and long-chain carbonic acid, which are the starting materials of the present invention, to be present in the reaction system are as follows:
2 to 30 weight in total amount of current: 2, preferably 2 to 20
It is better to use Chonghui%.

In the present invention, it is preferable to include a neutralizing base as a gatekeeper in the reaction system in order to improve the conductivity during electrolytic condensation. Neutralization tM
Examples of M include hydroxides, carbonates, bicarbonates, methylates, ethylates, and amine salts of lithium, potassium, sodium, calcium, magnesium, and the like. Among these, it is particularly preferable to use sodium and potassium hydroxides, carbonates, and methylates. The amount of neutralizing base added is not particularly limited, but it is usually determined by the degree of neutralization of the mixture of long-chain dicarboxylic acid monoester and long-chain carboxylic acid (hereinafter referred to as "mixed acid") (neutralization of the mixed acid). It is preferable to add CO so that the molar proportion neutralized by the base is 2 to 40 mol%, preferably 5 to 40 mol%.

As for the electrode materials used in the electrolytic condensation of the present invention, platinum, rhodium, ruthenium, iridium, etc. are used alone or in an alloy for the cathode, and are usually used as plating, and titanium, tantalum, etc. are used for the plating substrate. used. Further, the cathode preferably has a low hydrogen overvoltage, but is not particularly limited, and platinum, iron, stainless steel, titanium, etc. can be used.

The electrolytic condensation of the present invention is usually 1 to 40 A/6 m2,
Preferably, it is carried out at 5 to 6 m2, and the temperature of the electrolyte is usually 20 to 65°C, preferably 50 to 65°C.
It is carried out within the range of

As the electrolytic cell used for the electrolytic condensation of the present invention, a wide variety of electrolytic cells that are used in ordinary organic electrode reactions can be used, and for example, a beaker-shaped or box-shaped electrolytic cell may be used, or a filter press type may be used.

Next, the triacontanic acid ester represented by the general formula (3) obtained above is reduced to obtain 1-triacontanol. This reaction is usually used to convert the carboxylic acid ester to the corresponding primary alcohol. Reaction conditions for various reduction reactions can be widely applied. In the present invention, in particular, a reduction reaction using a composite reducing agent of sodium borohydride and a metal halide (aluminum chloride, calcium chloride, etc.),
It is desirable to employ reaction conditions such as a reduction reaction using a metal hydride such as lithium aluminum hydride, a catalytic reduction reaction, and the like.

More specifically, when using the above-mentioned composite reducing agent or metal hydride, these catalysts are usually used in an amount of about 1 to 2 times the mole of the 1-triacontanoic acid ester, preferably about 1,5 times the mole of the catalyst. It is better to use twice the molar amount. This reduction reaction is usually carried out in an ether solvent such as ethyl ether, tetrahydrofuran, or diglyme. The reaction temperature can be appropriately selected from room temperature to around the boiling point of the solvent, and the reaction is generally completed within about 2 to 24 hours. In addition, when using a catalytic reduction catalyst, a wide range of commonly used catalysts such as copper-chromium catalysts can be used as the catalytic reduction catalyst, and the catalyst is usually 0.1 to 0.7
It is preferable to use it in an amount of about 0.5 M% by weight.

The reduction reaction is usually carried out at 150 to 250 atmospheres and 200 to 1000 mm.
The reaction is preferably carried out at a temperature of about 200 atm and about 200°C, and the reaction is generally completed within 2 to 3 hours.

The long-chain dicarboxylic acid monoester used as a starting material in the present invention is preferably prepared by the method shown below. That is, a long-chain dicarboxylic acid represented by the general formula % (51 [wherein m is the same as above]) and an alcohol represented by the general formula % (61 [wherein R is the same as above]) are reacted. The reaction mixture obtained is extracted with hot n-hexane, and the long-chain dicarboxylic acid monoester represented by the general formula +1) precipitated by cooling the extract can be isolated.

A wide range of conventional esterification reaction conditions can be applied to the reaction between the long-chain dicarboxylic acid (6) and the alcohol (6). The ratio of long-chain dicarboxylic acid (5) and alcohol (6) to be used is not particularly limited and can be appropriately selected within a wide range, but usually the latter is used in an equimolar amount to 10 times the former, preferably an equimolar amount. It is better to use -2 times the mole. As the catalyst to be used, a wide variety of common esterification catalysts can be used, such as sulfuric acid, phosphoric acid, hydrochloric acid, p-toluenesulfonic acid, and the like. The amount of such catalyst used is usually 0.1 to 1% by weight, preferably 0.2 to 0.4% by weight based on the long chain dicarboxylic acid (5). The reaction is generally carried out in an aromatic hydrocarbon solvent such as toluene or xylene. The reaction is usually carried out at 70 to 150°C, preferably 80 to 110°C, and is generally completed in 1 to 5 hours. In addition to the long-chain dicarboxylic acid monoester, the long-chain dicarboxylic acid diester and unreacted long-chain dicarboxylic acid are present in the reaction mixture after the completion of the above reaction. Although these have similar boiling points and are difficult to separate by distillation or the like, the present inventors succeeded in isolating and purifying long-chain dicarboxylic acid monoester from the reaction mixture by using n-hexane. This is because long-chain dicarboxylic acid monoesters are soluble in hot n-hexane and insoluble in cold n-hexane, and long-chain dicarboxylic acid diesters are soluble in both hot and cold n-hexane. This method utilizes the property that unreacted long-chain dicarboxylic acid is insoluble in both hot and cold n-hexane, and this property was first discovered by the present inventors.

Utilizing such properties, in the present invention, the reaction mixture is first extracted with warm n-hexane. The temperature of n-hexane is usually 50°C or higher, preferably 55 to 65°C. After hot n-hexane extraction, long chain dicarboxylic acid monoesters and long chain dicarboxylic acid diesters are extracted. Next, this extract is usually 10°C or less, preferably 0 to 10°C.
When cooled to a certain degree, only the desired long-chain dicarboxylic acid monoester is precipitated, which can be isolated and purified.

1-Triacontanol produced in the present invention can be easily isolated and purified from the reaction mixture by conventionally known conventional means such as recrystallization, gas chromatography, 45 chromatography, column chromatography, etc. after the completion of the above reaction. Ru.

Examples are given below to further clarify the present invention.

Example 1 500y of octadecane-1,18-dicarboxylic acid and 50F of methanol are dissolved in toluene, then para-toluenesulfonic acid 21 is added as an esterification catalyst, and esterification is carried out at a temperature of 80' to 100°C. The water produced by the reaction is removed. After completion of the reaction, the reaction mixture was analyzed by gas chromatography, and it was found that octadecane-1,18-dicarboxylic acid, monomethyl octadecane-1,18-dicarboxylate, and dimethyl octadecane-1,18-dicarboxylate were 88.3% and 505%, respectively. %, it was included at a rate of 11.2%.

After washing the reaction mixture with water to remove the catalyst, toluene was recovered, and then 31 n-hexane was added and after boiling and stirring,
Dispose of the furnace immediately. Octadecane-1,1 from the insoluble part
210 g of 8-dicarboxylic acid were obtained. On the other hand, the p solution mainly contains monomethyl octadecane-1.18-dicarboxylate and dimethyl ophtadecane-1.18-dicarboxylate. Next, this P liquid is cooled to 5° C. and then separated into furnaces.

Collect n-hexane from the furnace liquid and convert it to octadecane-1,1
45 pieces of dimethyl 8-dicarboxylate were obtained.

Further, 245 g of crystals were obtained from the insoluble portion. This crystal C consists of 95 monomethyl octadecane-1,18-dicarboxylate.
．． It is contained in a proportion of 5%, and the rest is octadecane-1.
, 18-dicarboxylic acid 3.5%, octadecane-1,1
Dimethyl 8-dicarboxylate was 1.0%. Furthermore, this crystal was crystallized again with n-hexane to obtain 226 octadecane-1,18-dicarboxylic acid monomethyl with a purity of 98%.
I got 2.

Melting point 77.8-78.8℃, neutralization value 158.2 Example
2 (a) A 1 mm thick titanium plate (3.0 cm x 8
．． 0C77Z) plated with 4 micron platinum, and a 1 mm thick stainless steel plate (8,0C77Z) as the cathode.
cm x 8. (Ocm) at intervals of approximately 5 cm. Additionally, install a thermometer and reflux condenser.

Lauric acid 4.0y (0.02 mol), octadecane-
1,18-carboxylic acid monomethyl ester 7.4y
(0.02 mol), water 1. (l and potassium hydroxide 0.
A solution of 224y (0,004 mol) dissolved in 50y of methanol was introduced into the above electrolytic cell, and electrolysis was carried out under constant current conditions (0.45 A) at 50 to 60°C with vigorous stirring using a Magtin stirrer. conduct. Is the current carrying area of both positive and negative electrodes 1.5cr1? and the current density is 6 A/
It will be 6m2. The octadecane-1,18-dicarboxylic acid monoester reaction mixture was cooled to room temperature, and the precipitated white solid was filtered under reduced pressure. After removing methanol from the solution using a vacuum trowel, the remaining solution was acidified and extracted with ether, and 1.20P of lauryl M and some 10.25' of monomethyl octadecanedicarboxylate were recovered from the ether solution. As a result of analysis by gas chromatography, the separated solid contained the raw material monomethyl octadecane-1,18-dicarboxylate, the main product methyl triacontanoate, and a small amount of tocosan. After dissolving this solid in hot n-hexane, fractional crystallization yielded 2.0 y of methyl octadecanedicarboxylate, 4.
50y and tocosan 0.132. The grooved structure of the obtained methyl triacontanate was confirmed by comparing the behavior in various spectroscopic spectra and the melting point with the standard sample. Furthermore, as a result of gas chromatography flea analysis, it has a purity of about 98%. Consumed octadecanedicarboxylic acid monomethyl ester (reaction rate: 70%
) The yields of methyl triacontanate and tocosan were 67% and 3%, respectively.

(b) Dissolve 2.40y (0,005 mol) of methyl 1-triacontanoate obtained in (a) above in rtl of dry ethyl ether (or tetrano-hydrofuran), and hydrogenate an equimolar amount. A composite reducing agent (also ζ and lithium aluminum hydride) consisting of boron trifluoride and calcium chloride is added dropwise to suspended dry ethyl ether (or tetrahydrofuran) while cooling in a water bath. After the dropwise addition was completed, the reaction mixture was refluxed for 2 hours, and then
After treatment according to the conventional method, 1-triacontanol (5191~95%) is obtained.The purity is 99.0%~9.
9.8% Example 3 In Example 2, 0.0% palmitic acid was used instead of lauric acid.
1-triacontanol was obtained in a yield of 54% in the same manner as in Example 2(a) and (b), using 002 mol of monomethyl tabucinate instead of 02 mol and monomethyl octadecane-1,18-dicarboxylate. Ta.

Example 4 Caprin MO,0 was used instead of lauric acid in Example 2.
2 mol and 0.02 mol of eicosane-1,20-dicarboxylic acid monomethyl instead of octadecane-1,18-dicarboxylic acid monomethyl, 1-triacone was prepared in the same manner as Actual and Prediction 2(a) and (b). 58% tanol
It was obtained in a yield of .

Example 5 In Example 2, 0.0% stearic acid was used instead of lauric acid.
In the same manner as in Example 2(a) and (b), using 0.02 mol of monomethyl dodecane-1,12-dicarboxylate instead of monomethyl octadecane-1,18-dicarboxylate, Contanol 53%
It was obtained in a yield of .

(that's all)

Claims (1)

[Claims] ■ General formula % formula % [In the formula, R is an alkyl group and m is an integer of 12 to 20. ] A long chain dicarboxylic acid monoester represented by the general formula % formula % [wherein n represents an integer of 8 to 16]. A long-chain carboxylic acid represented by 1 is subjected to cross-Kolbe type electrolytic condensation in an alcohol solution to give the formula % [where R, m and n are the same as above]. However, the total of m and n is 28. ] A method for producing 1-triacontanol, which comprises obtaining a triacontanic acid ester represented by the following formula, and then reducing the same to obtain 1-triacontanol represented by the formula %. ■ General formula % formula % [In the formula, m represents an integer of 12 to 20. A long-chain dicarboxylic acid represented by the general formula [wherein R represents an alkyl group]. ] The resulting reaction mixture is extracted with warm n-hexane, and the extract is then cooled to precipitate the monoester, and then this monoester and the general Formula CFja (CH2) n C00H [in the formula, n is 8 to
Indicates 16 integers. '' is subjected to cross-Kolbe type electrolytic condensation in an alcohol solution with a long-chain carbon 0 represented by the formula % [wherein R, m and n are the same as above]. However, the total of m and n is 28. ] A method for producing 1-triacontanol, which comprises obtaining a triacontanic acid ester represented by the following formula, and further reducing the triacontanol to obtain 1-triacontanol represented by the formula %.